| Current File : //usr/share/info/libmicrohttpd.info |
This is libmicrohttpd.info, produced by makeinfo version 4.13 from
libmicrohttpd.texi.
This manual is for GNU libmicrohttpd (version 0.9.37, 24 April 2014), a
library for embedding an HTTP(S) server into C applications.
Copyright (C) 2007-2013 Christian Grothoff
Permission is granted to copy, distribute and/or modify this
document under the terms of the GNU Free Documentation License,
Version 1.3 or any later version published by the Free Software
Foundation; with no Invariant Sections, no Front-Cover Texts, and
no Back-Cover Texts. A copy of the license is included in the
section entitled "GNU Free Documentation License".
INFO-DIR-SECTION Software libraries
START-INFO-DIR-ENTRY
* libmicrohttpd: (libmicrohttpd). Embedded HTTP server library.
END-INFO-DIR-ENTRY
File: libmicrohttpd.info, Node: Top, Next: microhttpd-intro, Up: (dir)
The GNU libmicrohttpd Library
*****************************
This manual is for GNU libmicrohttpd (version 0.9.37, 24 April 2014), a
library for embedding an HTTP(S) server into C applications.
Copyright (C) 2007-2013 Christian Grothoff
Permission is granted to copy, distribute and/or modify this
document under the terms of the GNU Free Documentation License,
Version 1.3 or any later version published by the Free Software
Foundation; with no Invariant Sections, no Front-Cover Texts, and
no Back-Cover Texts. A copy of the license is included in the
section entitled "GNU Free Documentation License".
* Menu:
* microhttpd-intro:: Introduction.
* microhttpd-const:: Constants.
* microhttpd-struct:: Structures type definition.
* microhttpd-cb:: Callback functions definition.
* microhttpd-init:: Starting and stopping the server.
* microhttpd-inspect:: Implementing external `select'.
* microhttpd-requests:: Handling requests.
* microhttpd-responses:: Building responses to requests.
* microhttpd-flow:: Flow control.
* microhttpd-dauth:: Utilizing Authentication.
* microhttpd-post:: Adding a `POST' processor.
* microhttpd-info:: Obtaining and modifying status information.
Appendices
* GNU-LGPL:: The GNU Lesser General Public License says how you
can copy and share almost all of `libmicrohttpd'.
* GNU GPL with eCos Extension:: The GNU General Public License with eCos extension says how you
can copy and share some parts of `libmicrohttpd'.
* GNU-FDL:: The GNU Free Documentation License says how you
can copy and share the documentation of `libmicrohttpd'.
Indices
* Concept Index:: Index of concepts and programs.
* Function and Data Index:: Index of functions, variables and data types.
* Type Index:: Index of data types.
File: libmicrohttpd.info, Node: microhttpd-intro, Next: microhttpd-const, Prev: Top, Up: Top
1 Introduction
**************
All symbols defined in the public API start with `MHD_'. MHD is a
small HTTP daemon library. As such, it does not have any API for
logging errors (you can only enable or disable logging to stderr).
Also, it may not support all of the HTTP features directly, where
applicable, portions of HTTP may have to be handled by clients of the
library.
The library is supposed to handle everything that it must handle
(because the API would not allow clients to do this), such as basic
connection management; however, detailed interpretations of headers --
such as range requests -- and HTTP methods are left to clients. The
library does understand `HEAD' and will only send the headers of the
response and not the body, even if the client supplied a body. The
library also understands headers that control connection management
(specifically, `Connection: close' and `Expect: 100 continue' are
understood and handled automatically).
MHD understands `POST' data and is able to decode certain formats
(at the moment only `application/x-www-form-urlencoded' and
`multipart/form-data') using the post processor API. The data stream
of a POST is also provided directly to the main application, so
unsupported encodings could still be processed, just not conveniently
by MHD.
The header file defines various constants used by the HTTP protocol.
This does not mean that MHD actually interprets all of these values.
The provided constants are exported as a convenience for users of the
library. MHD does not verify that transmitted HTTP headers are part of
the standard specification; users of the library are free to define
their own extensions of the HTTP standard and use those with MHD.
All functions are guaranteed to be completely reentrant and
thread-safe. MHD checks for allocation failures and tries to recover
gracefully (for example, by closing the connection). Additionally,
clients can specify resource limits on the overall number of
connections, number of connections per IP address and memory used per
connection to avoid resource exhaustion.
1.1 Scope
=========
MHD is currently used in a wide range of implementations. Examples
based on reports we've received from developers include:
* Embedded HTTP server on a cortex M3 (128 KB code space)
* Large-scale multimedia server (reportedly serving at the
simulator limit of 7.5 GB/s)
* Administrative console (via HTTP/HTTPS) for network appliances
1.2 Thread modes and event loops
================================
MHD supports four basic thread modes and up to three event loop styes.
The four basic thread modes are external (MHD creates no threads,
event loop is fully managed by the application), internal (MHD creates
one thread for all connections), thread pool (MHD creates a thread pool
which is used to process all connections) and thread-per-connection
(MHD creates one listen thread and then one thread per accepted
connection).
These thread modes are then combined with the event loop styles.
MHD support select, poll and epoll. epoll is only available on Linux,
poll may not be available on some platforms. Note that it is possible
to combine MHD using epoll with an external select-based event loop.
The default (if no other option is passed) is "external select".
The highest performance can typically be obtained with a thread pool
using `epoll'. Apache Benchmark (ab) was used to compare the
performance of `select' and `epoll' when using a thread pool and a
large number of connections. *note fig:performance:: shows the
resulting plot from the `benchmark.c' example, which measures the
latency between an incoming request and the completion of the
transmission of the response. In this setting, the `epoll' thread pool
with four threads was able to handle more than 45,000 connections per
second on loopback (with Apache Benchmark running three processes on
the same machine).
Figure 1.1: Performance measurements for select vs. epoll (with
thread-pool).
Not all combinations of thread modes and event loop styles are
supported. This is partially to keep the API simple, and partially
because some combinations simply make no sense as others are strictly
superior. Note that the choice of style depends fist of all on the
application logic, and then on the performance requirements.
Applications that perform a blocking operation while handling a request
within the callbacks from MHD must use a thread per connection. This
is typically rather costly. Applications that do not support threads
or that must run on embedded devices without thread-support must use
the external mode. Using `epoll' is only supported on Linux, thus
portable applications must at least have a fallback option available.
*note tbl:supported:: lists the sane combinations.
select poll epoll
external yes no yes
internal yes yes yes
thread pool yes yes yes
thread-per-connection yes yes no
Table 1.1: Supported combinations of event styles and thread modes.
1.3 Compiling GNU libmicrohttpd
===============================
MHD uses the standard GNU system where the usual build process involves
running
$ ./configure
$ make
$ make install
MHD supports various options to be given to configure to tailor the
binary to a specific situation. Note that some of these options will
remove portions of the MHD code that are required for
binary-compatibility. They should only be used on embedded systems
with tight resource constraints and no concerns about library
versioning. Standard distributions including MHD are expected to
always ship with all features enabled, otherwise unexpected
incompatibilities can arise!
Here is a list of MHD-specific options that can be given to configure
(canonical configure options such as "-prefix" are also supported, for a
full list of options run "./configure -help"):
```--disable-curl'''
disable running testcases using libcurl
```--disable-largefile'''
disable support for 64-bit files
```--disable-messages'''
disable logging of error messages (smaller binary size, not so
much fun for debugging)
```--disable-https'''
disable HTTPS support, even if GNUtls is found; this option must
be used if eCOS license is desired as an option (in all cases the
resulting binary falls under a GNU LGPL-only license)
```--disable-postprocessor'''
do not include the post processor API (results in binary
incompatibility)
```--disable-dauth'''
do not include the authentication APIs (results in binary
incompatibility)
```--disable-epoll'
do not include epoll support, even on Linux (minimally smaller
binary size, good for testing portability to non-Linux systems)
```--enable-coverage'''
set flags for analysis of code-coverage with gcc/gcov (results in
slow, large binaries)
```--with-gcrypt=PATH'''
specifies path to libgcrypt installation
```--with-gnutls=PATH'''
specifies path to libgnutls installation
1.4 Including the microhttpd.h header
=====================================
Ideally, before including "microhttpd.h" you should add the necessary
includes to define the `uint64_t', `size_t', `fd_set', `socklen_t' and
`struct sockaddr' data types. Which specific headers are needed may
depend on your platform and your build system might include some tests
to provide you with the necessary conditional operations. For possible
suggestions consult `platform.h' and `configure.ac' in the MHD
distribution.
Once you have ensured that you manually (!) included the right
headers for your platform before "microhttpd.h", you should also add a
line with `#define MHD_PLATFORM_H' which will prevent the
"microhttpd.h" header from trying (and, depending on your platform,
failing) to include the right headers.
If you do not define MHD_PLATFORM_H, the "microhttpd.h" header will
automatically include headers needed on GNU/Linux systems (possibly
causing problems when porting to other platforms).
1.5 SIGPIPE
===========
MHD does not install a signal handler for SIGPIPE. On platforms where
this is possible (such as GNU/Linux), it disables SIGPIPE for its I/O
operations (by passing MSG_NOSIGNAL). On other platforms, SIGPIPE
signals may be generated from network operations by MHD and will cause
the process to die unless the developer explicitly installs a signal
handler for SIGPIPE.
Hence portable code using MHD must install a SIGPIPE handler or
explicitly block the SIGPIPE signal. MHD does not do so in order to
avoid messing with other parts of the application that may need to
handle SIGPIPE in a particular way. You can make your application
handle SIGPIPE by calling the following function in `main':
static void
catcher (int sig)
{
}
static void
ignore_sigpipe ()
{
struct sigaction oldsig;
struct sigaction sig;
sig.sa_handler = &catcher;
sigemptyset (&sig.sa_mask);
#ifdef SA_INTERRUPT
sig.sa_flags = SA_INTERRUPT; /* SunOS */
#else
sig.sa_flags = SA_RESTART;
#endif
if (0 != sigaction (SIGPIPE, &sig, &oldsig))
fprintf (stderr,
"Failed to install SIGPIPE handler: %s\n", strerror (errno));
}
1.6 MHD_UNSIGNED_LONG_LONG
==========================
Some platforms do not support `long long'. Hence MHD defines a macro
`MHD_UNSIGNED LONG_LONG' which will default to `unsigned long long'.
For standard desktop operating systems, this is all you need to know.
However, if your platform does not support `unsigned long long', you
should change "platform.h" to define `MHD_LONG_LONG' and
`MHD_UNSIGNED_LONG_LONG' to an appropriate alternative type and also
define `MHD_LONG_LONG_PRINTF' and `MHD_UNSIGNED_LONG_LONG_PRINTF' to
the corresponding format string for printing such a data type. Note
that the "signed" versions are deprecated. Also, for historical
reasons, `MHD_LONG_LONG_PRINTF' is without the percent sign, whereas
`MHD_UNSIGNED_LONG_LONG_PRINTF' is with the percent sign. Newly
written code should only use the unsigned versions. However, you need
to define both in "platform.h" if you need to change the definition for
the specific platform.
1.7 Portability to W32
======================
libmicrohttpd in general ported well to W32. Most libmicrohttpd features
are supported. W32 do not support some functions, like epoll and
corresponding MHD features are not available on W32.
1.8 Portability to z/OS
=======================
To compile MHD on z/OS, extract the archive and run
iconv -f UTF-8 -t IBM-1047 contrib/ascebc > /tmp/ascebc.sh
chmod +x /tmp/ascebc.sh
for n in `find * -type f`
do
/tmp/ascebc.sh $n
done
to convert all source files to EBCDIC. Note that you must run
`configure' from the directory where the configure script is located.
Otherwise, configure will fail to find the `contrib/xcc' script (which
is a wrapper around the z/OS c89 compiler).
File: libmicrohttpd.info, Node: microhttpd-const, Next: microhttpd-struct, Prev: microhttpd-intro, Up: Top
2 Constants
***********
-- Enumeration: MHD_FLAG
Options for the MHD daemon.
Note that if neither `MHD_USE_THREAD_PER_CONNECTION' nor
`MHD_USE_SELECT_INTERNALLY' is used, the client wants control over
the process and will call the appropriate microhttpd callbacks.
Starting the daemon may also fail if a particular option is not
implemented or not supported on the target platform (i.e. no
support for SSL, threads or IPv6). SSL support generally depends
on options given during MHD compilation. Threaded operations
(including `MHD_USE_SELECT_INTERNALLY') are not supported on
Symbian.
`MHD_NO_FLAG'
No options selected.
`MHD_USE_DEBUG'
Run in debug mode. If this flag is used, the library should
print error messages and warnings to stderr. Note that for
this run-time option to have any effect, MHD needs to be
compiled with messages enabled. This is done by default
except you ran configure with the `--disable-messages' flag
set.
`MHD_USE_SSL'
Run in HTTPS-mode. If you specify `MHD_USE_SSL' and MHD was
compiled without SSL support, `MHD_start_daemon' will return
NULL.
`MHD_USE_THREAD_PER_CONNECTION'
Run using one thread per connection.
`MHD_USE_SELECT_INTERNALLY'
Run using an internal thread doing `SELECT'.
`MHD_USE_IPv6'
Run using the IPv6 protocol (otherwise, MHD will just support
IPv4). If you specify `MHD_USE_IPV6' and the local platform
does not support it, `MHD_start_daemon' will return NULL.
If you want MHD to support IPv4 and IPv6 using a single
socket, pass MHD_USE_DUAL_STACK, otherwise, if you only pass
this option, MHD will try to bind to IPv6-only (resulting in
no IPv4 support).
`MHD_USE_DUAL_STACK'
Use a single socket for IPv4 and IPv6. Note that this will
mean that IPv4 addresses are returned by MHD in the
IPv6-mapped format (the 'struct sockaddr_in6' format will be
used for IPv4 and IPv6).
`MHD_USE_PEDANTIC_CHECKS'
Be pedantic about the protocol (as opposed to as tolerant as
possible). Specifically, at the moment, this flag causes MHD
to reject HTTP 1.1 connections without a `Host' header. This
is required by the standard, but of course in violation of
the "be as liberal as possible in what you accept" norm. It
is recommended to turn this *ON* if you are testing clients
against MHD, and *OFF* in production.
`MHD_USE_POLL'
Use poll instead of select. This allows sockets with
descriptors `>= FD_SETSIZE'. This option currently only
works in conjunction with `MHD_USE_THREAD_PER_CONNECTION' or
`MHD_USE_INTERNAL_SELECT' (at this point). If you specify
`MHD_USE_POLL' and the local platform does not support it,
`MHD_start_daemon' will return NULL.
`MHD_USE_EPOLL_LINUX_ONLY'
Use epoll instead of poll or select. This allows sockets with
descriptors `>= FD_SETSIZE'. This option is only available on
Linux systems and only works in conjunction with
`MHD_USE_THREAD_PER_CONNECTION' (at this point). If you
specify `MHD_USE_EPOLL_LINUX_ONLY' and the local platform
does not support it, `MHD_start_daemon' will return NULL.
Using epoll instead of select or poll can in some situations
result in significantly higher performance as the system call
has fundamentally lower complexity (O(1) for epoll vs. O(n)
for select/poll where n is the number of open connections).
`MHD_SUPPRESS_DATE_NO_CLOCK'
Suppress (automatically) adding the 'Date:' header to HTTP
responses. This option should ONLY be used on systems that
do not have a clock and that DO provide other mechanisms for
cache control. See also RFC 2616, section 14.18 (exception
3).
`MHD_USE_NO_LISTEN_SOCKET'
Run the HTTP server without any listen socket. This option
only makes sense if `MHD_add_connection' is going to be used
exclusively to connect HTTP clients to the HTTP server. This
option is incompatible with using a thread pool; if it is
used, `MHD_OPTION_THREAD_POOL_SIZE' is ignored.
`MHD_USE_PIPE_FOR_SHUTDOWN'
Force MHD to use a signal pipe to notify the event loop (of
threads) of our shutdown. This is required if an appliction
uses `MHD_USE_INTERNAL_SELECT' or
`MHD_USE_THREAD_PER_CONNECTION' and then performs
`MHD_quiesce_daemon' (which eliminates our ability to signal
termination via the listen socket). In these modes,
`MHD_quiesce_daemon' will fail if this option was not set.
Also, use of this option is automatic (as in, you do not even
have to specify it), if `MHD_USE_NO_LISTEN_SOCKET' is
specified. In "external" select mode, this option is always
simply ignored.
`MHD_USE_SUSPEND_RESUME'
Enables using `MHD_suspend_connection' and
`MHD_resume_connection', as performing these calls requires
some additional pipes to be created, and code not using these
calls should not pay the cost.
`MHD_USE_TCP_FASTOPEN'
Enable TCP_FASTOPEN on the listen socket. TCP_FASTOPEN is
currently supported on Linux >= 3.6. On other systems using
this option with cause `MHD_start_daemon' to fail.
-- Enumeration: MHD_OPTION
MHD options. Passed in the varargs portion of
`MHD_start_daemon()'.
`MHD_OPTION_END'
No more options / last option. This is used to terminate the
VARARGs list.
`MHD_OPTION_CONNECTION_MEMORY_LIMIT'
Maximum memory size per connection (followed by a `size_t').
The default is 32 kB (32*1024 bytes) as defined by the
internal constant `MHD_POOL_SIZE_DEFAULT'. Values above 128k
are unlikely to result in much benefit, as half of the memory
will be typically used for IO, and TCP buffers are unlikely
to support window sizes above 64k on most systems.
`MHD_OPTION_CONNECTION_MEMORY_INCREMENT'
Increment to use for growing the read buffer (followed by a
`size_t'). The default is 1024 (bytes). Increasing this
value will make MHD use memory for reading more aggressively,
which can reduce the number of `recvfrom' calls but may
increase the number of `sendto' calls. The given value must
fit within MHD_OPTION_CONNECTION_MEMORY_LIMIT.
`MHD_OPTION_CONNECTION_LIMIT'
Maximum number of concurrent connections to accept (followed
by an `unsigned int'). The default is `FD_SETSIZE - 4' (the
maximum number of file descriptors supported by `select' minus
four for `stdin', `stdout', `stderr' and the server socket).
In other words, the default is as large as possible.
Note that if you set a low connection limit, you can easily
get into trouble with browsers doing request pipelining. For
example, if your connection limit is "1", a browser may open
a first connection to access your "index.html" file, keep it
open but use a second connection to retrieve CSS files,
images and the like. In fact, modern browsers are typically
by default configured for up to 15 parallel connections to a
single server. If this happens, MHD will refuse to even
accept the second connection until the first connection is
closed -- which does not happen until timeout. As a result,
the browser will fail to render the page and seem to hang.
If you expect your server to operate close to the connection
limit, you should first consider using a lower timeout value
and also possibly add a "Connection: close" header to your
response to ensure that request pipelining is not used and
connections are closed immediately after the request has
completed:
MHD_add_response_header (response,
MHD_HTTP_HEADER_CONNECTION,
"close");
`MHD_OPTION_CONNECTION_TIMEOUT'
After how many seconds of inactivity should a connection
automatically be timed out? (followed by an `unsigned int';
use zero for no timeout). The default is zero (no timeout).
`MHD_OPTION_NOTIFY_COMPLETED'
Register a function that should be called whenever a request
has been completed (this can be used for application-specific
clean up). Requests that have never been presented to the
application (via `MHD_AccessHandlerCallback()') will not
result in notifications.
This option should be followed by *TWO* pointers. First a
pointer to a function of type `MHD_RequestCompletedCallback()'
and second a pointer to a closure to pass to the request
completed callback. The second pointer maybe `NULL'.
`MHD_OPTION_PER_IP_CONNECTION_LIMIT'
Limit on the number of (concurrent) connections made to the
server from the same IP address. Can be used to prevent one
IP from taking over all of the allowed connections. If the
same IP tries to establish more than the specified number of
connections, they will be immediately rejected. The option
should be followed by an `unsigned int'. The default is
zero, which means no limit on the number of connections from
the same IP address.
`MHD_OPTION_SOCK_ADDR'
Bind daemon to the supplied socket address. This option
should be followed by a `struct sockaddr *'. If
`MHD_USE_IPv6' is specified, the `struct sockaddr*' should
point to a `struct sockaddr_in6', otherwise to a `struct
sockaddr_in'. If this option is not specified, the daemon
will listen to incoming connections from anywhere. If you
use this option, the 'port' argument from `MHD_start_daemon'
is ignored and the port from the given `struct sockaddr *'
will be used instead.
`MHD_OPTION_URI_LOG_CALLBACK'
Specify a function that should be called before parsing the
URI from the client. The specified callback function can be
used for processing the URI (including the options) before it
is parsed. The URI after parsing will no longer contain the
options, which maybe inconvenient for logging. This option
should be followed by two arguments, the first one must be of
the form
void * my_logger(void * cls, const char * uri, struct MHD_Connection *con)
where the return value will be passed as `*con_cls' in calls
to the `MHD_AccessHandlerCallback' when this request is
processed later; returning a value of `NULL' has no special
significance; (however, note that if you return non-`NULL',
you can no longer rely on the first call to the access
handler having `NULL == *con_cls' on entry) `cls' will be set
to the second argument following MHD_OPTION_URI_LOG_CALLBACK.
Finally, `uri' will be the 0-terminated URI of the request.
Note that during the time of this call, most of the
connection's state is not initialized (as we have not yet
parsed he headers). However, information about the
connecting client (IP, socket) is available.
`MHD_OPTION_HTTPS_MEM_KEY'
Memory pointer to the private key to be used by the HTTPS
daemon. This option should be followed by an "const char*"
argument. This should be used in conjunction with
'MHD_OPTION_HTTPS_MEM_CERT'.
`MHD_OPTION_HTTPS_MEM_CERT'
Memory pointer to the certificate to be used by the HTTPS
daemon. This option should be followed by an "const char*"
argument. This should be used in conjunction with
'MHD_OPTION_HTTPS_MEM_KEY'.
`MHD_OPTION_HTTPS_MEM_TRUST'
Memory pointer to the CA certificate to be used by the HTTPS
daemon to authenticate and trust clients certificates. This
option should be followed by an "const char*" argument. The
presence of this option activates the request of certificate
to the client. The request to the client is marked optional,
and it is the responsibility of the server to check the
presence of the certificate if needed. Note that most
browsers will only present a client certificate only if they
have one matching the specified CA, not sending any
certificate otherwise.
`MHD_OPTION_HTTPS_CRED_TYPE'
Daemon credentials type. Either certificate or anonymous,
this option should be followed by one of the values listed in
"enum gnutls_credentials_type_t".
`MHD_OPTION_HTTPS_PRIORITIES'
SSL/TLS protocol version and ciphers. This option must be
followed by an "const char *" argument specifying the SSL/TLS
protocol versions and ciphers that are acceptable for the
application. The string is passed unchanged to
gnutls_priority_init. If this option is not specified,
"NORMAL" is used.
`MHD_OPTION_HTTPS_CERT_CALLBACK'
Use a callback to determine which X.509 certificate should be
used for a given HTTPS connection. This option should be
followed by a argument of type
"gnutls_certificate_retrieve_function2 *". This option
provides an alternative to MHD_OPTION_HTTPS_MEM_KEY and
MHD_OPTION_HTTPS_MEM_CERT. You must use this version if
multiple domains are to be hosted at the same IP address
using TLS's Server Name Indication (SNI) extension. In this
case, the callback is expected to select the correct
certificate based on the SNI information provided. The
callback is expected to access the SNI data using
gnutls_server_name_get(). Using this option requires GnuTLS
3.0 or higher.
`MHD_OPTION_DIGEST_AUTH_RANDOM'
Digest Authentication nonce's seed.
This option should be followed by two arguments. First an
integer of type "size_t" which specifies the size of the
buffer pointed to by the second argument in bytes. Note that
the application must ensure that the buffer of the second
argument remains allocated and unmodified while the daemon is
running. For security, you SHOULD provide a fresh random
nonce when using MHD with Digest Authentication.
`MHD_OPTION_NONCE_NC_SIZE'
Size of an array of nonce and nonce counter map. This option
must be followed by an "unsigned int" argument that have the
size (number of elements) of a map of a nonce and a
nonce-counter. If this option is not specified, a default
value of 4 will be used (which might be too small for servers
handling many requests). If you do not use digest
authentication at all, you can specify a value of zero to
save some memory.
You should calculate the value of NC_SIZE based on the number
of connections per second multiplied by your expected session
duration plus a factor of about two for hash table
collisions. For example, if you expect 100
digest-authenticated connections per second and the average
user to stay on your site for 5 minutes, then you likely need
a value of about 60000. On the other hand, if you can only
expect only 10 digest-authenticated connections per second,
tolerate browsers getting a fresh nonce for each request and
expect a HTTP request latency of 250 ms, then a value of
about 5 should be fine.
`MHD_OPTION_LISTEN_SOCKET'
Listen socket to use. Pass a listen socket for MHD to use
(systemd-style). If this option is used, MHD will not open
its own listen socket(s). The argument passed must be of type
"int" and refer to an existing socket that has been bound to
a port and is listening.
`MHD_OPTION_EXTERNAL_LOGGER'
Use the given function for logging error messages. This
option must be followed by two arguments; the first must be a
pointer to a function of type 'void fun(void * arg, const
char * fmt, va_list ap)' and the second a pointer of type
'void*' which will be passed as the "arg" argument to "fun".
Note that MHD will not generate any log messages without the
MHD_USE_DEBUG flag set and if MHD was compiled with the
"-disable-messages" flag.
`MHD_OPTION_THREAD_POOL_SIZE'
Number (unsigned int) of threads in thread pool. Enable
thread pooling by setting this value to to something greater
than 1. Currently, thread model must be
MHD_USE_SELECT_INTERNALLY if thread pooling is enabled
(`MHD_start_daemon' returns `NULL' for an unsupported thread
model).
`MHD_OPTION_ARRAY'
This option can be used for initializing MHD using options
from an array. A common use for this is writing an FFI for
MHD. The actual options given are in an array of 'struct
MHD_OptionItem', so this option requires a single argument of
type 'struct MHD_OptionItem'. The array must be terminated
with an entry `MHD_OPTION_END'.
An example for code using MHD_OPTION_ARRAY is:
struct MHD_OptionItem ops[] = {
{ MHD_OPTION_CONNECTION_LIMIT, 100, NULL },
{ MHD_OPTION_CONNECTION_TIMEOUT, 10, NULL },
{ MHD_OPTION_END, 0, NULL }
};
d = MHD_start_daemon(0, 8080, NULL, NULL, dh, NULL,
MHD_OPTION_ARRAY, ops,
MHD_OPTION_END);
For options that expect a single pointer argument, the second
member of the `struct MHD_OptionItem' is ignored. For
options that expect two pointer arguments, the first argument
must be cast to `intptr_t'.
`MHD_OPTION_UNESCAPE_CALLBACK'
Specify a function that should be called for unescaping escape
sequences in URIs and URI arguments. Note that this function
will NOT be used by the MHD_PostProcessor. If this option is
not specified, the default method will be used which decodes
escape sequences of the form "%HH". This option should be
followed by two arguments, the first one must be of the form
size_t my_unescaper(void * cls, struct MHD_Connection *c, char *s)
where the return value must be `strlen(s)' and `s' should be
updated. Note that the unescape function must not lengthen
`s' (the result must be shorter than the input and still be
0-terminated). `cls' will be set to the second argument
following MHD_OPTION_UNESCAPE_CALLBACK.
`MHD_OPTION_THREAD_STACK_SIZE'
Maximum stack size for threads created by MHD. This option
must be followed by a `size_t'). Not specifying this option
or using a value of zero means using the system default
(which is likely to differ based on your platform).
`MHD_OPTION_TCP_FASTQUEUE_QUEUE_SIZE'
When the flag `MHD_USE_TCP_FASTOPEN' is used, this option
sets the connection handshake queue size for the TCP FASTOPEN
connections. Note that a TCP FASTOPEN connection handshake
occupies more resources than a TCP handshake as the SYN
packets also contain DATA which is kept in the associate
state until handshake is completed. If this option is not
given the queue size is set to a default value of 10. This
option must be followed by a `unsigned int'.
`MHD_OPTION_HTTPS_MEM_DHPARAMS'
Memory pointer for the Diffie-Hellman parameters (dh.pem) to
be used by the HTTPS daemon for key exchange. This option
must be followed by a `const char *' argument. The argument
would be a zero-terminated string with a PEM encoded PKCS3 DH
parameters structure suitable for passing to
`gnutls_dh_parms_import_pkcs3'.
-- C Struct: MHD_OptionItem
Entry in an MHD_OPTION_ARRAY. See the `MHD_OPTION_ARRAY' option
argument for its use.
The `option' member is used to specify which option is specified
in the array. The other members specify the respective argument.
Note that for options taking only a single pointer, the
`ptr_value' member should be set. For options taking two pointer
arguments, the first pointer must be cast to `intptr_t' and both
the `value' and the `ptr_value' members should be used to pass the
two pointers.
-- Enumeration: MHD_ValueKind
The `MHD_ValueKind' specifies the source of the key-value pairs in
the HTTP protocol.
`MHD_RESPONSE_HEADER_KIND'
Response header.
`MHD_HEADER_KIND'
HTTP header.
`MHD_COOKIE_KIND'
Cookies. Note that the original HTTP header containing the
cookie(s) will still be available and intact.
`MHD_POSTDATA_KIND'
`POST' data. This is available only if a content encoding
supported by MHD is used (currently only URL encoding), and
only if the posted content fits within the available memory
pool. Note that in that case, the upload data given to the
`MHD_AccessHandlerCallback()' will be empty (since it has
already been processed).
`MHD_GET_ARGUMENT_KIND'
`GET' (URI) arguments.
`MHD_FOOTER_KIND'
HTTP footer (only for http 1.1 chunked encodings).
-- Enumeration: MHD_RequestTerminationCode
The `MHD_RequestTerminationCode' specifies reasons why a request
has been terminated (or completed).
`MHD_REQUEST_TERMINATED_COMPLETED_OK'
We finished sending the response.
`MHD_REQUEST_TERMINATED_WITH_ERROR'
Error handling the connection (resources exhausted, other
side closed connection, application error accepting request,
etc.)
`MHD_REQUEST_TERMINATED_TIMEOUT_REACHED'
No activity on the connection for the number of seconds
specified using `MHD_OPTION_CONNECTION_TIMEOUT'.
`MHD_REQUEST_TERMINATED_DAEMON_SHUTDOWN'
We had to close the session since MHD was being shut down.
-- Enumeration: MHD_ResponseMemoryMode
The `MHD_ResponeMemoryMode' specifies how MHD should treat the
memory buffer given for the response in
`MHD_create_response_from_buffer'.
`MHD_RESPMEM_PERSISTENT'
Buffer is a persistent (static/global) buffer that won't
change for at least the lifetime of the response, MHD should
just use it, not free it, not copy it, just keep an alias to
it.
`MHD_RESPMEM_MUST_FREE'
Buffer is heap-allocated with `malloc' (or equivalent) and
should be freed by MHD after processing the response has
concluded (response reference counter reaches zero).
`MHD_RESPMEM_MUST_COPY'
Buffer is in transient memory, but not on the heap (for
example, on the stack or non-malloc allocated) and only valid
during the call to `MHD_create_response_from_buffer'. MHD
must make its own private copy of the data for processing.
File: libmicrohttpd.info, Node: microhttpd-struct, Next: microhttpd-cb, Prev: microhttpd-const, Up: Top
3 Structures type definition
****************************
-- C Struct: MHD_Daemon
Handle for the daemon (listening on a socket for HTTP traffic).
-- C Struct: MHD_Connection
Handle for a connection / HTTP request. With HTTP/1.1, multiple
requests can be run over the same connection. However, MHD will
only show one request per TCP connection to the client at any
given time.
-- C Struct: MHD_Response
Handle for a response.
-- C Struct: MHD_PostProcessor
Handle for `POST' processing.
-- C Union: MHD_ConnectionInfo
Information about a connection.
-- C Union: MHD_DaemonInfo
Information about an MHD daemon.
File: libmicrohttpd.info, Node: microhttpd-cb, Next: microhttpd-init, Prev: microhttpd-struct, Up: Top
4 Callback functions definition
*******************************
-- Function Pointer: int *MHD_AcceptPolicyCallback (void *cls, const
struct sockaddr * addr, socklen_t addrlen)
Invoked in the context of a connection to allow or deny a client to
connect. This callback return `MHD_YES' if connection is allowed,
`MHD_NO' if not.
CLS
custom value selected at callback registration time;
ADDR
address information from the client;
ADDRLEN
length of the address information.
-- Function Pointer: int *MHD_AccessHandlerCallback (void *cls, struct
MHD_Connection * connection, const char *url, const char
*method, const char *version, const char *upload_data, size_t
*upload_data_size, void **con_cls)
Invoked in the context of a connection to answer a request from the
client. This callback must call MHD functions (example: the
`MHD_Response' ones) to provide content to give back to the client
and return an HTTP status code (i.e. `200' for OK, `404', etc.).
*note microhttpd-post::, for details on how to code this callback.
Must return `MHD_YES' if the connection was handled successfully,
`MHD_NO' if the socket must be closed due to a serious error while
handling the request
CLS
custom value selected at callback registration time;
URL
the URL requested by the client;
METHOD
the HTTP method used by the client (`GET', `PUT', `DELETE',
`POST', etc.);
VERSION
the HTTP version string (i.e. `HTTP/1.1');
UPLOAD_DATA
the data being uploaded (excluding headers):
* for a `POST' that fits into memory and that is encoded
with a supported encoding, the `POST' data will *NOT* be
given in UPLOAD_DATA and is instead available as part of
`MHD_get_connection_values()';
* very large `POST' data *will* be made available
incrementally in UPLOAD_DATA;
UPLOAD_DATA_SIZE
set initially to the size of the UPLOAD_DATA provided; this
callback must update this value to the number of bytes *NOT*
processed; unless external select is used, the callback maybe
required to process at least some data. If the callback
fails to process data in multi-threaded or internal-select
mode and if the read-buffer is already at the maximum size
that MHD is willing to use for reading (about half of the
maximum amount of memory allowed for the connection), then
MHD will abort handling the connection and return an internal
server error to the client. In order to avoid this, clients
must be able to process upload data incrementally and reduce
the value of `upload_data_size'.
CON_CLS
reference to a pointer, initially set to `NULL', that this
callback can set to some address and that will be preserved
by MHD for future calls for this request;
since the access handler may be called many times (i.e., for a
`PUT'/`POST' operation with plenty of upload data) this allows
the application to easily associate some request-specific
state;
if necessary, this state can be cleaned up in the global
`MHD_RequestCompletedCallback' (which can be set with the
`MHD_OPTION_NOTIFY_COMPLETED').
-- Function Pointer: void *MHD_RequestCompletedCallback (void *cls,
struct MHD_Connectionconnection, void **con_cls, enum
MHD_RequestTerminationCode toe)
Signature of the callback used by MHD to notify the application
about completed requests.
CLS
custom value selected at callback registration time;
CONNECTION
connection handle;
CON_CLS
value as set by the last call to the
`MHD_AccessHandlerCallback';
TOE
reason for request termination see
`MHD_OPTION_NOTIFY_COMPLETED'.
-- Function Pointer: int *MHD_KeyValueIterator (void *cls, enum
MHD_ValueKind kind, const char *key, const char *value)
Iterator over key-value pairs. This iterator can be used to
iterate over all of the cookies, headers, or `POST'-data fields of
a request, and also to iterate over the headers that have been
added to a response.
CLS
custom value specified when iteration was triggered;
KIND
kind of the header we are looking at
KEY
key for the value, can be an empty string
VALUE
value corresponding value, can be NULL
Return `MHD_YES' to continue iterating, `MHD_NO' to abort the
iteration.
-- Function Pointer: int *MHD_ContentReaderCallback (void *cls,
uint64_t pos, char *buf, size_t max)
Callback used by MHD in order to obtain content. The callback has
to copy at most MAX bytes of content into BUF. The total number
of bytes that has been placed into BUF should be returned.
Note that returning zero will cause MHD to try again. Thus,
returning zero should only be used in conjunction with
`MHD_suspend_connection()' to avoid busy waiting.
While usually the callback simply returns the number of bytes
written into BUF, there are two special return value:
`MHD_CONTENT_READER_END_OF_STREAM' (-1) should be returned for the
regular end of transmission (with chunked encoding, MHD will then
terminate the chunk and send any HTTP footers that might be
present; without chunked encoding and given an unknown response
size, MHD will simply close the connection; note that while
returning `MHD_CONTENT_READER_END_OF_STREAM' is not technically
legal if a response size was specified, MHD accepts this and
treats it just as `MHD_CONTENT_READER_END_WITH_ERROR'.
`MHD_CONTENT_READER_END_WITH_ERROR' (-2) is used to indicate a
server error generating the response; this will cause MHD to simply
close the connection immediately. If a response size was given or
if chunked encoding is in use, this will indicate an error to the
client. Note, however, that if the client does not know a
response size and chunked encoding is not in use, then clients
will not be able to tell the difference between
`MHD_CONTENT_READER_END_WITH_ERROR' and
`MHD_CONTENT_READER_END_OF_STREAM'. This is not a limitation of
MHD but rather of the HTTP protocol.
CLS
custom value selected at callback registration time;
POS
position in the datastream to access; note that if an
`MHD_Response' object is re-used, it is possible for the same
content reader to be queried multiple times for the same
data; however, if an `MHD_Response' is not re-used, MHD
guarantees that POS will be the sum of all non-negative
return values obtained from the content reader so far.
Return `-1' on error (MHD will no longer try to read content and
instead close the connection with the client).
-- Function Pointer: void *MHD_ContentReaderFreeCallback (void *cls)
This method is called by MHD if we are done with a content reader.
It should be used to free resources associated with the content
reader.
-- Function Pointer: int *MHD_PostDataIterator (void *cls, enum
MHD_ValueKind kind, const char *key, const char *filename,
const char *content_type, const char *transfer_encoding,
const char *data, uint64_t off, size_t size)
Iterator over key-value pairs where the value maybe made available
in increments and/or may not be zero-terminated. Used for
processing `POST' data.
CLS
custom value selected at callback registration time;
KIND
type of the value;
KEY
zero-terminated key for the value;
FILENAME
name of the uploaded file, `NULL' if not known;
CONTENT_TYPE
mime-type of the data, `NULL' if not known;
TRANSFER_ENCODING
encoding of the data, `NULL' if not known;
DATA
pointer to size bytes of data at the specified offset;
OFF
offset of data in the overall value;
SIZE
number of bytes in data available.
Return `MHD_YES' to continue iterating, `MHD_NO' to abort the
iteration.
File: libmicrohttpd.info, Node: microhttpd-init, Next: microhttpd-inspect, Prev: microhttpd-cb, Up: Top
5 Starting and stopping the server
**********************************
-- Function: void MHD_set_panic_func (MHD_PanicCallback cb, void *cls)
Set a handler for fatal errors.
CB
function to call if MHD encounters a fatal internal error.
If no handler was set explicitly, MHD will call `abort'.
CLS
closure argument for cb; the other arguments are the name of
the source file, line number and a string describing the
nature of the fatal error (which can be `NULL')
-- Function: struct MHD_Daemon * MHD_start_daemon (unsigned int flags,
unsigned short port, MHD_AcceptPolicyCallback apc, void
*apc_cls, MHD_AccessHandlerCallback dh, void *dh_cls, ...)
Start a webserver on the given port.
FLAGS
OR-ed combination of `MHD_FLAG' values;
PORT
port to bind to;
APC
callback to call to check which clients will be allowed to
connect; you can pass `NULL' in which case connections from
any IP will be accepted;
APC_CLS
extra argument to APC;
DH
default handler for all URIs;
DH_CLS
extra argument to DH.
Additional arguments are a list of options (type-value pairs,
terminated with `MHD_OPTION_END'). It is mandatory to use
`MHD_OPTION_END' as last argument, even when there are no
additional arguments.
Return `NULL' on error, handle to daemon on success.
-- Function: int MHD_quiesce_daemon (struct MHD_Daemon *daemon)
Stop accepting connections from the listening socket. Allows
clients to continue processing, but stops accepting new
connections. Note that the caller is responsible for closing the
returned socket; however, if MHD is run using threads (anything
but external select mode), it must not be closed until AFTER
`MHD_stop_daemon' has been called (as it is theoretically possible
that an existing thread is still using it).
This function is useful in the special case that a listen socket
is to be migrated to another process (i.e. a newer version of the
HTTP server) while existing connections should continue to be
processed until they are finished.
Return `-1' on error (daemon not listening), the handle to the
listen socket otherwise.
-- Function: void MHD_stop_daemon (struct MHD_Daemon *daemon)
Shutdown an HTTP daemon.
-- Function: int MHD_run (struct MHD_Daemon *daemon)
Run webserver operations (without blocking unless in client
callbacks). This method should be called by clients in
combination with `MHD_get_fdset()' if the client-controlled
`select'-method is used.
This function will work for external `poll' and `select' mode.
However, if using external `select' mode, you may want to instead
use `MHD_run_from_select', as it is more efficient.
DAEMON
daemon to process connections of
Return `MHD_YES' on success, `MHD_NO' if this daemon was not
started with the right options for this call.
-- Function: int MHD_run_from_select (struct MHD_Daemon *daemon, const
fd_set *read_fd_set, const fd_set *write_fd_set, const fd_set
*except_fd_set)
Run webserver operations given sets of ready socket handles.
This method should be called by clients in combination with
`MHD_get_fdset' if the client-controlled (external) select method
is used.
You can use this function instead of `MHD_run' if you called
`select' on the result from `MHD_get_fdset'. File descriptors in
the sets that are not controlled by MHD will be ignored. Calling
this function instead of `MHD_run' is more efficient as MHD will
not have to call `select' again to determine which operations are
ready.
DAEMON
daemon to process connections of
READ_FD_SET
set of descriptors that must be ready for reading without
blocking
WRITE_FD_SET
set of descriptors that must be ready for writing without
blocking
EXCEPT_FD_SET
ignored, can be NULL
Return `MHD_YES' on success, `MHD_NO' on serious internal errors.
-- Function: void MHD_add_connection (struct MHD_Daemon *daemon, int
client_socket, const struct sockaddr *addr, socklen_t addrlen)
Add another client connection to the set of connections managed by
MHD. This API is usually not needed (since MHD will accept
inbound connections on the server socket). Use this API in
special cases, for example if your HTTP server is behind NAT and
needs to connect out to the HTTP client, or if you are building a
proxy.
If you use this API in conjunction with a internal select or a
thread pool, you must set the option `MHD_USE_PIPE_FOR_SHUTDOWN' to
ensure that the freshly added connection is immediately processed
by MHD.
The given client socket will be managed (and closed!) by MHD after
this call and must no longer be used directly by the application
afterwards.
DAEMON
daemon that manages the connection
CLIENT_SOCKET
socket to manage (MHD will expect to receive an HTTP request
from this socket next).
ADDR
IP address of the client
ADDRLEN
number of bytes in addr
This function will return `MHD_YES' on success, `MHD_NO' if this
daemon could not handle the connection (i.e. malloc failed, etc).
The socket will be closed in any case; 'errno' is set to indicate
further details about the error.
File: libmicrohttpd.info, Node: microhttpd-inspect, Next: microhttpd-requests, Prev: microhttpd-init, Up: Top
6 Implementing external `select'
********************************
-- Function: int MHD_get_fdset (struct MHD_Daemon *daemon, fd_set *
read_fd_set, fd_set * write_fd_set, fd_set * except_fd_set,
int *max_fd)
Obtain the `select()' sets for this daemon. The daemon's socket is
added to READ_FD_SET. The list of currently existent connections
is scanned and their file descriptors added to the correct set.
After the call completed successfully: the variable referenced by
MAX_FD references the file descriptor with highest integer
identifier. The variable must be set to zero before invoking this
function.
Return `MHD_YES' on success, `MHD_NO' if: the arguments are
invalid (example: `NULL' pointers); this daemon was not started
with the right options for this call.
-- Function: int MHD_get_timeout (struct MHD_Daemon *daemon, unsigned
long long *timeout)
Obtain timeout value for select for this daemon (only needed if
connection timeout is used). The returned value is how long
`select' should at most block, not the timeout value set for
connections. This function must not be called if the
`MHD_USE_THREAD_PER_CONNECTION' mode is in use (since then it is
not meaningful to ask for a timeout, after all, there is
concurrenct activity). The function must also not be called by
user-code if `MHD_USE_INTERNAL_SELECT' is in use. In the latter
case, the behavior is undefined.
DAEMON
which daemon to obtain the timeout from.
TIMEOUT
will be set to the timeout (in milliseconds).
Return `MHD_YES' on success, `MHD_NO' if timeouts are not used (or
no connections exist that would necessiate the use of a timeout
right now).
File: libmicrohttpd.info, Node: microhttpd-requests, Next: microhttpd-responses, Prev: microhttpd-inspect, Up: Top
7 Handling requests
*******************
-- Function: int MHD_get_connection_values (struct MHD_Connection
*connection, enum MHD_ValueKind kind, MHD_KeyValueIterator
iterator, void *iterator_cls)
Get all the headers matching KIND from the request.
The ITERATOR callback is invoked once for each header, with
ITERATOR_CLS as first argument. After version 0.9.19, the headers
are iterated in the same order as they were received from the
network; previous versions iterated over the headers in reverse
order.
`MHD_get_connection_values' returns the number of entries iterated
over; this can be less than the number of headers if, while
iterating, ITERATOR returns `MHD_NO'.
ITERATOR can be `NULL': in this case this function just counts and
returns the number of headers.
In the case of `MHD_GET_ARGUMENT_KIND', the VALUE argument will be
`NULL' if the URL contained a key without an equals operator. For
example, for a HTTP request to the URL "http://foo/bar?key", the
VALUE argument is `NULL'; in contrast, a HTTP request to the URL
"http://foo/bar?key=", the VALUE argument is the empty string.
The normal case is that the URL contains "http://foo/bar?key=value"
in which case VALUE would be the string "value" and KEY would
contain the string "key".
-- Function: int MHD_set_connection_value (struct MHD_Connection
*connection, enum MHD_ValueKind kind, const char * key, const
char * value)
This function can be used to append an entry to the list of HTTP
headers of a connection (so that the `MHD_get_connection_values
function' will return them - and the MHD PostProcessor will also
see them). This maybe required in certain situations (see Mantis
#1399) where (broken) HTTP implementations fail to supply values
needed by the post processor (or other parts of the application).
This function MUST only be called from within the
MHD_AccessHandlerCallback (otherwise, access maybe improperly
synchronized). Furthermore, the client must guarantee that the
key and value arguments are 0-terminated strings that are NOT
freed until the connection is closed. (The easiest way to do this
is by passing only arguments to permanently allocated strings.).
CONNECTION is the connection for which the entry for KEY of the
given KIND should be set to the given VALUE.
The function returns `MHD_NO' if the operation could not be
performed due to insufficient memory and `MHD_YES' on success.
-- Function: const char * MHD_lookup_connection_value (struct
MHD_Connection *connection, enum MHD_ValueKind kind, const
char *key)
Get a particular header value. If multiple values match the KIND,
return one of them (the "first", whatever that means). KEY must
reference a zero-terminated ASCII-coded string representing the
header to look for: it is compared against the headers using
`strcasecmp()', so case is ignored. A value of `NULL' for KEY can
be used to lookup 'trailing' values without a key, for example if
a URI is of the form "http://example.com/?trailer", a KEY of
`NULL' can be used to access "tailer" The function returns `NULL'
if no matching item was found.
File: libmicrohttpd.info, Node: microhttpd-responses, Next: microhttpd-flow, Prev: microhttpd-requests, Up: Top
8 Building responses to requests
********************************
Response objects handling by MHD is asynchronous with respect to the
application execution flow. Instances of the `MHD_Response' structure
are not associated to a daemon and neither to a client connection: they
are managed with reference counting.
In the simplest case: we allocate a new `MHD_Response' structure for
each response, we use it once and finally we destroy it.
MHD allows more efficient resources usages.
Example: we allocate a new `MHD_Response' structure for each
response *kind*, we use it every time we have to give that response and
we finally destroy it only when the daemon shuts down.
* Menu:
* microhttpd-response enqueue:: Enqueuing a response.
* microhttpd-response create:: Creating a response object.
* microhttpd-response headers:: Adding headers to a response.
* microhttpd-response inspect:: Inspecting a response object.
File: libmicrohttpd.info, Node: microhttpd-response enqueue, Next: microhttpd-response create, Up: microhttpd-responses
8.1 Enqueuing a response
========================
-- Function: int MHD_queue_response (struct MHD_Connection
*connection, unsigned int status_code, struct MHD_Response
*response)
Queue a response to be transmitted to the client as soon as
possible but only after MHD_AccessHandlerCallback returns. This
function checks that it is legal to queue a response at this time
for the given connection. It also increments the internal
reference counter for the response object (the counter will be
decremented automatically once the response has been transmitted).
CONNECTION
the connection identifying the client;
STATUS_CODE
HTTP status code (i.e. `200' for OK);
RESPONSE
response to transmit.
Return `MHD_YES' on success or if message has been queued. Return
`MHD_NO': if arguments are invalid (example: `NULL' pointer); on
error (i.e. reply already sent).
-- Function: void MHD_destroy_response (struct MHD_Response *response)
Destroy a response object and associated resources (decrement the
reference counter). Note that MHD may keep some of the resources
around if the response is still in the queue for some clients, so
the memory may not necessarily be freed immediately.
An explanation of reference counting(1):
1. a `MHD_Response' object is allocated:
struct MHD_Response * response = MHD_create_response_from_buffer(...);
/* here: reference counter = 1 */
2. the `MHD_Response' object is enqueued in a `MHD_Connection':
MHD_queue_response(connection, , response);
/* here: reference counter = 2 */
3. the creator of the response object discharges responsibility for
it:
MHD_destroy_response(response);
/* here: reference counter = 1 */
4. the daemon handles the connection sending the response's data to
the client then decrements the reference counter by calling
`MHD_destroy_response()': the counter's value drops to zero and
the `MHD_Response' object is released.
---------- Footnotes ----------
(1) Note to readers acquainted to the Tcl API: reference counting on
`MHD_Connection' structures is handled in the same way as Tcl handles
`Tcl_Obj' structures through `Tcl_IncrRefCount()' and
`Tcl_DecrRefCount()'.
File: libmicrohttpd.info, Node: microhttpd-response create, Next: microhttpd-response headers, Prev: microhttpd-response enqueue, Up: microhttpd-responses
8.2 Creating a response object
==============================
-- Function: struct MHD_Response * MHD_create_response_from_callback
(uint64_t size, size_t block_size, MHD_ContentReaderCallback
crc, void *crc_cls, MHD_ContentReaderFreeCallback crfc)
Create a response object. The response object can be extended with
header information and then it can be used any number of times.
SIZE
size of the data portion of the response, `-1' for unknown;
BLOCK_SIZE
preferred block size for querying CRC (advisory only, MHD may
still call CRC using smaller chunks); this is essentially the
buffer size used for IO, clients should pick a value that is
appropriate for IO and memory performance requirements;
CRC
callback to use to obtain response data;
CRC_CLS
extra argument to CRC;
CRFC
callback to call to free CRC_CLS resources.
Return `NULL' on error (i.e. invalid arguments, out of memory).
-- Function: struct MHD_Response * MHD_create_response_from_fd
(uint64_t size, int fd)
Create a response object. The response object can be extended with
header information and then it can be used any number of times.
SIZE
size of the data portion of the response (should be smaller
or equal to the size of the file)
FD
file descriptor referring to a file on disk with the data;
will be closed when response is destroyed; note that 'fd'
must be an actual file descriptor (not a pipe or socket)
since MHD might use 'sendfile' or 'seek' on it. The
descriptor should be in blocking-IO mode.
Return `NULL' on error (i.e. invalid arguments, out of memory).
-- Function: struct MHD_Response *
MHD_create_response_from_fd_at_offset (uint64_t size, int fd, off_t
offset)
Create a response object. The response object can be extended with
header information and then it can be used any number of times.
Note that you need to be a bit careful about `off_t' when writing
this code. Depending on your platform, MHD is likely to have been
compiled with support for 64-bit files. When you compile your own
application, you must make sure that `off_t' is also a 64-bit
value. If not, your compiler may pass a 32-bit value as `off_t',
which will result in 32-bits of garbage.
If you use the autotools, use the `AC_SYS_LARGEFILE' autoconf
macro and make sure to include the generated `config.h' file
before `microhttpd.h' to avoid problems. If you do not have a
build system and only want to run on a GNU/Linux system, you could
also use #define _FILE_OFFSET_BITS 64
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <microhttpd.h>
to ensure 64-bit `off_t'. Note that if your operating system
does not support 64-bit files, MHD will be compiled with a 32-bit
`off_t' (in which case the above would be wrong).
SIZE
size of the data portion of the response (number of bytes to
transmit from the file starting at offset).
FD
file descriptor referring to a file on disk with the data;
will be closed when response is destroyed; note that 'fd'
must be an actual file descriptor (not a pipe or socket)
since MHD might use 'sendfile' or 'seek' on it. The
descriptor should be in blocking-IO mode.
OFFSET
offset to start reading from in the file
Return `NULL' on error (i.e. invalid arguments, out of memory).
-- Function: struct MHD_Response * MHD_create_response_from_buffer
(size_t size, void *data, enum MHD_ResponseMemoryMode mode)
Create a response object. The response object can be extended with
header information and then it can be used any number of times.
SIZE
size of the data portion of the response;
BUFFER
the data itself;
MODE
memory management options for buffer; use
MHD_RESPMEM_PERSISTENT if the buffer is static/global memory,
use MHD_RESPMEM_MUST_FREE if the buffer is heap-allocated and
should be freed by MHD and MHD_RESPMEM_MUST_COPY if the
buffer is in transient memory (i.e. on the stack) and must be
copied by MHD;
Return `NULL' on error (i.e. invalid arguments, out of memory).
-- Function: struct MHD_Response * MHD_create_response_from_data
(size_t size, void *data, int must_free, int must_copy)
Create a response object. The response object can be extended with
header information and then it can be used any number of times.
This function is deprecated, use `MHD_create_response_from_buffer'
instead.
SIZE
size of the data portion of the response;
DATA
the data itself;
MUST_FREE
if true: MHD should free data when done;
MUST_COPY
if true: MHD allocates a block of memory and use it to make a
copy of DATA embedded in the returned `MHD_Response'
structure; handling of the embedded memory is responsibility
of MHD; DATA can be released anytime after this call returns.
Return `NULL' on error (i.e. invalid arguments, out of memory).
Example: create a response from a statically allocated string:
const char * data = "<html><body><p>Error!</p></body></html>";
struct MHD_Connection * connection = ...;
struct MHD_Response * response;
response = MHD_create_response_from_buffer (strlen(data), data,
MHD_RESPMEM_PERSISTENT);
MHD_queue_response(connection, 404, response);
MHD_destroy_response(response);
File: libmicrohttpd.info, Node: microhttpd-response headers, Next: microhttpd-response inspect, Prev: microhttpd-response create, Up: microhttpd-responses
8.3 Adding headers to a response
================================
-- Function: int MHD_add_response_header (struct MHD_Response
*response, const char *header, const char *content)
Add a header line to the response. The strings referenced by
HEADER and CONTENT must be zero-terminated and they are duplicated
into memory blocks embedded in RESPONSE.
Notice that the strings must not hold newlines, carriage returns
or tab chars.
Return `MHD_NO' on error (i.e. invalid header or content format or
memory allocation error).
-- Function: int MHD_add_response_footer (struct MHD_Response
*response, const char *footer, const char *content)
Add a footer line to the response. The strings referenced by
FOOTER and CONTENT must be zero-terminated and they are duplicated
into memory blocks embedded in RESPONSE.
Notice that the strings must not hold newlines, carriage returns
or tab chars. You can add response footers at any time before
signalling the end of the response to MHD (not just before calling
'MHD_queue_response'). Footers are useful for adding
cryptographic checksums to the reply or to signal errors
encountered during data generation. This call was introduced in
MHD 0.9.3.
Return `MHD_NO' on error (i.e. invalid header or content format or
memory allocation error).
-- Function: int MHD_del_response_header (struct MHD_Response
*response, const char *header, const char *content)
Delete a header (or footer) line from the response. Return
`MHD_NO' on error (arguments are invalid or no such header known).
File: libmicrohttpd.info, Node: microhttpd-response inspect, Prev: microhttpd-response headers, Up: microhttpd-responses
8.4 Inspecting a response object
================================
-- Function: int MHD_get_response_headers (struct MHD_Response
*response, MHD_KeyValueIterator iterator, void *iterator_cls)
Get all of the headers added to a response.
Invoke the ITERATOR callback for each header in the response,
using ITERATOR_CLS as first argument. Return number of entries
iterated over. ITERATOR can be `NULL': in this case the function
just counts headers.
ITERATOR should not modify the its key and value arguments, unless
we know what we are doing.
-- Function: const char * MHD_get_response_header (struct MHD_Response
*response, const char *key)
Find and return a pointer to the value of a particular header from
the response. KEY must reference a zero-terminated string
representing the header to look for. The search is case sensitive.
Return `NULL' if header does not exist or KEY is `NULL'.
We should not modify the value, unless we know what we are doing.
File: libmicrohttpd.info, Node: microhttpd-flow, Next: microhttpd-dauth, Prev: microhttpd-responses, Up: Top
9 Flow control.
***************
Sometimes it may be possible that clients upload data faster than an
application can process it, or that an application needs an extended
period of time to generate a response. If
`MHD_USE_THREAD_PER_CONNECTION' is used, applications can simply deal
with this by performing their logic within the thread and thus
effectively blocking connection processing by MHD. In all other modes,
blocking logic must not be placed within the callbacks invoked by MHD
as this would also block processing of other requests, as a single
thread may be responsible for tens of thousands of connections.
Instead, applications using thread modes other than
`MHD_USE_THREAD_PER_CONNECTION' should use the following functions to
perform flow control.
-- Function: int MHD_suspend_connection (struct MHD_Connection
*connection)
Suspend handling of network data for a given connection. This can
be used to dequeue a connection from MHD's event loop (external
select, internal select or thread pool; not applicable to
thread-per-connection!) for a while.
If you use this API in conjunction with a internal select or a
thread pool, you must set the option `MHD_USE_SUSPEND_RESUME' to
ensure that a resumed connection is immediately processed by MHD.
Suspended connections continue to count against the total number of
connections allowed (per daemon, as well as per IP, if such limits
are set). Suspended connections will NOT time out; timeouts will
restart when the connection handling is resumed. While a
connection is suspended, MHD will not detect disconnects by the
client.
The only safe time to suspend a connection is from the
`MHD_AccessHandlerCallback'.
Finally, it is an API violation to call `MHD_stop_daemon' while
having suspended connections (this will at least create memory and
socket leaks or lead to undefined behavior). You must explicitly
resume all connections before stopping the daemon.
CONNECTION
the connection to suspend
-- Function: int MHD_resume_connection (struct MHD_Connection
*connection)
Resume handling of network data for suspended connection. It is
safe to resume a suspended connection at any time. Calling this
function on a connection that was not previously suspended will
result in undefined behavior.
CONNECTION
the connection to resume
File: libmicrohttpd.info, Node: microhttpd-dauth, Next: microhttpd-post, Prev: microhttpd-flow, Up: Top
10 Utilizing Authentication
***************************
MHD support three types of client authentication.
Basic authentication uses a simple authentication method based on
BASE64 algorithm. Username and password are exchanged in clear between
the client and the server, so this method must only be used for
non-sensitive content or when the session is protected with https.
When using basic authentication MHD will have access to the clear
password, possibly allowing to create a chained authentication toward
an external authentication server.
Digest authentication uses a one-way authentication method based on
MD5 hash algorithm. Only the hash will transit over the network, hence
protecting the user password. The nonce will prevent replay attacks.
This method is appropriate for general use, especially when https is
not used to encrypt the session.
Client certificate authentication uses a X.509 certificate from the
client. This is the strongest authentication mechanism but it requires
the use of HTTPS. Client certificate authentication can be used
simultaneously with Basic or Digest Authentication in order to provide
a two levels authentication (like for instance separate machine and
user authentication). A code example for using client certificates is
presented in the MHD tutorial.
* Menu:
* microhttpd-dauth basic:: Using Basic Authentication.
* microhttpd-dauth digest:: Using Digest Authentication.
File: libmicrohttpd.info, Node: microhttpd-dauth basic, Next: microhttpd-dauth digest, Up: microhttpd-dauth
10.1 Using Basic Authentication
===============================
-- Function: char * MHD_basic_auth_get_username_password (struct
MHD_Connection *connection, char** password)
Get the username and password from the basic authorization header
sent by the client. Return `NULL' if no username could be found,
a pointer to the username if found. If returned value is not
`NULL', the value must be `free()''ed.
PASSWORD reference a buffer to store the password. It can be
`NULL'. If returned value is not `NULL', the value must be
`free()''ed.
-- Function: int MHD_queue_basic_auth_fail_response (struct
MHD_Connection *connection, const char *realm, struct
MHD_Response *response)
Queues a response to request basic authentication from the client.
Return `MHD_YES' if successful, otherwise `MHD_NO'.
REALM must reference to a zero-terminated string representing the
realm.
RESPONSE a response structure to specify what shall be presented
to the client with a 401 HTTP status.
File: libmicrohttpd.info, Node: microhttpd-dauth digest, Prev: microhttpd-dauth basic, Up: microhttpd-dauth
10.2 Using Digest Authentication
================================
-- Function: char * MHD_digest_auth_get_username (struct
MHD_Connection *connection)
Find and return a pointer to the username value from the request
header. Return `NULL' if the value is not found or header does
not exist. If returned value is not `NULL', the value must be
`free()''ed.
-- Function: int MHD_digest_auth_check (struct MHD_Connection
*connection, const char *realm, const char *username, const
char *password, unsigned int nonce_timeout)
Checks if the provided values in the WWW-Authenticate header are
valid and sound according to RFC2716. If valid return `MHD_YES',
otherwise return `MHD_NO'.
REALM must reference to a zero-terminated string representing the
realm.
USERNAME must reference to a zero-terminated string representing
the username, it is usually the returned value from
MHD_digest_auth_get_username.
PASSWORD must reference to a zero-terminated string representing
the password, most probably it will be the result of a lookup of
the username against a local database.
NONCE_TIMEOUT is the amount of time in seconds for a nonce to be
invalid. Most of the time it is sound to specify 300 seconds as
its values.
-- Function: int MHD_queue_auth_fail_response (struct MHD_Connection
*connection, const char *realm, const char *opaque, struct
MHD_Response *response, int signal_stale)
Queues a response to request authentication from the client,
return `MHD_YES' if successful, otherwise `MHD_NO'.
REALM must reference to a zero-terminated string representing the
realm.
OPAQUE must reference to a zero-terminated string representing a
value that gets passed to the client and expected to be passed
again to the server as-is. This value can be a hexadecimal or
base64 string.
RESPONSE a response structure to specify what shall be presented
to the client with a 401 HTTP status.
SIGNAL_STALE a value that signals "stale=true" in the response
header to indicate the invalidity of the nonce and no need to ask
for authentication parameters and only a new nonce gets generated.
`MHD_YES' to generate a new nonce, `MHD_NO' to ask for
authentication parameters.
Example: handling digest authentication requests and responses.
#define PAGE "<html><head><title>libmicrohttpd demo</title></head><body>Access granted</body></html>"
#define DENIED "<html><head><title>libmicrohttpd demo</title></head><body>Access denied</body></html>"
#define OPAQUE "11733b200778ce33060f31c9af70a870ba96ddd4"
static int
ahc_echo (void *cls,
struct MHD_Connection *connection,
const char *url,
const char *method,
const char *version,
const char *upload_data, size_t *upload_data_size, void **ptr)
{
struct MHD_Response *response;
char *username;
const char *password = "testpass";
const char *realm = "test@example.com";
int ret;
username = MHD_digest_auth_get_username(connection);
if (username == NULL)
{
response = MHD_create_response_from_buffer(strlen (DENIED),
DENIED,
MHD_RESPMEM_PERSISTENT);
ret = MHD_queue_auth_fail_response(connection, realm,
OPAQUE,
response,
MHD_NO);
MHD_destroy_response(response);
return ret;
}
ret = MHD_digest_auth_check(connection, realm,
username,
password,
300);
free(username);
if ( (ret == MHD_INVALID_NONCE) ||
(ret == MHD_NO) )
{
response = MHD_create_response_from_buffer(strlen (DENIED),
DENIED,
MHD_RESPMEM_PERSISTENT);
if (NULL == response)
return MHD_NO;
ret = MHD_queue_auth_fail_response(connection, realm,
OPAQUE,
response,
(ret == MHD_INVALID_NONCE) ? MHD_YES : MHD_NO);
MHD_destroy_response(response);
return ret;
}
response = MHD_create_response_from_buffer (strlen(PAGE), PAGE,
MHD_RESPMEM_PERSISTENT);
ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
MHD_destroy_response(response);
return ret;
}
File: libmicrohttpd.info, Node: microhttpd-post, Next: microhttpd-info, Prev: microhttpd-dauth, Up: Top
11 Adding a `POST' processor
****************************
* Menu:
* microhttpd-post api:: Programming interface for the
`POST' processor.
MHD provides the post processor API to make it easier for applications
to parse the data of a client's `POST' request: the
`MHD_AccessHandlerCallback' will be invoked multiple times to process
data as it arrives; at each invocation a new chunk of data must be
processed. The arguments UPLOAD_DATA and UPLOAD_DATA_SIZE are used to
reference the chunk of data.
When `MHD_AccessHandlerCallback' is invoked for a new connection:
its `*CON_CLS' argument is set to `NULL'. When `POST' data comes in the
upload buffer it is *mandatory* to use the CON_CLS to store a reference
to per-connection data. The fact that the pointer was initially `NULL'
can be used to detect that this is a new request.
One method to detect that a new connection was established is to set
`*con_cls' to an unused integer:
int
access_handler (void *cls,
struct MHD_Connection * connection,
const char *url,
const char *method, const char *version,
const char *upload_data, size_t *upload_data_size,
void **con_cls)
{
static int old_connection_marker;
int new_connection = (NULL == *con_cls);
if (new_connection)
{
/* new connection with POST */
*con_cls = &old_connection_marker;
}
...
}
In contrast to the previous example, for `POST' requests in particular,
it is more common to use the value of `*con_cls' to keep track of
actual state used during processing, such as the post processor (or a
struct containing a post processor):
int
access_handler (void *cls,
struct MHD_Connection * connection,
const char *url,
const char *method, const char *version,
const char *upload_data, size_t *upload_data_size,
void **con_cls)
{
struct MHD_PostProcessor * pp = *con_cls;
if (pp == NULL)
{
pp = MHD_create_post_processor(connection, ...);
*con_cls = pp;
return MHD_YES;
}
if (*upload_data_size)
{
MHD_post_process(pp, upload_data, *upload_data_size);
*upload_data_size = 0;
return MHD_YES;
}
else
{
MHD_destroy_post_processor(pp);
return MHD_queue_response(...);
}
}
Note that the callback from `MHD_OPTION_NOTIFY_COMPLETED' should be
used to destroy the post processor. This cannot be done inside of the
access handler since the connection may not always terminate normally.
File: libmicrohttpd.info, Node: microhttpd-post api, Up: microhttpd-post
11.1 Programming interface for the `POST' processor
===================================================
-- Function: struct MHD_PostProcessor * MHD_create_post_processor
(struct MHD_Connection *connection, size_t buffer_size,
MHD_PostDataIterator iterator, void *iterator_cls)
Create a PostProcessor. A PostProcessor can be used to
(incrementally) parse the data portion of a `POST' request.
CONNECTION
the connection on which the `POST' is happening (used to
determine the `POST' format);
BUFFER_SIZE
maximum number of bytes to use for internal buffering (used
only for the parsing, specifically the parsing of the keys).
A tiny value (256-1024) should be sufficient; do *NOT* use a
value smaller than 256; for good performance, use 32k or 64k
(i.e. 65536).
ITERATOR
iterator to be called with the parsed data; must *NOT* be
`NULL';
ITERATOR_CLS
custom value to be used as first argument to ITERATOR.
Return `NULL' on error (out of memory, unsupported encoding),
otherwise a PP handle.
-- Function: int MHD_post_process (struct MHD_PostProcessor *pp, const
char *post_data, size_t post_data_len)
Parse and process `POST' data. Call this function when `POST'
data is available (usually during an `MHD_AccessHandlerCallback')
with the UPLOAD_DATA and UPLOAD_DATA_SIZE. Whenever possible,
this will then cause calls to the
`MHD_IncrementalKeyValueIterator'.
PP
the post processor;
POST_DATA
POST_DATA_LEN bytes of `POST' data;
POST_DATA_LEN
length of POST_DATA.
Return `MHD_YES' on success, `MHD_NO' on error (out-of-memory,
iterator aborted, parse error).
-- Function: int MHD_destroy_post_processor (struct MHD_PostProcessor
*pp)
Release PostProcessor resources. After this function is being
called, the PostProcessor is guaranteed to no longer call its
iterator. There is no special call to the iterator to indicate
the end of the post processing stream. After destroying the
PostProcessor, the programmer should perform any necessary work to
complete the processing of the iterator.
Return `MHD_YES' if processing completed nicely, `MHD_NO' if there
were spurious characters or formatting problems with the post
request. It is common to ignore the return value of this function.
File: libmicrohttpd.info, Node: microhttpd-info, Next: GNU-LGPL, Prev: microhttpd-post, Up: Top
12 Obtaining and modifying status information.
**********************************************
* Menu:
* microhttpd-info daemon:: State information about an MHD daemon
* microhttpd-info conn:: State information about a connection
* microhttpd-option conn:: Modify per-connection options
File: libmicrohttpd.info, Node: microhttpd-info daemon, Next: microhttpd-info conn, Up: microhttpd-info
12.1 Obtaining state information about an MHD daemon
====================================================
-- Function: const union MHD_DaemonInfo * MHD_get_daemon_info (struct
MHD_Daemon *daemon, enum MHD_DaemonInfoType infoType, ...)
Obtain information about the given daemon. This function is
currently not fully implemented.
DAEMON
the daemon about which information is desired;
INFOTYPE
type of information that is desired
...
additional arguments about the desired information (depending
on infoType)
Returns a union with the respective member (depending on infoType)
set to the desired information), or `NULL' in case the desired
information is not available or applicable.
-- Enumeration: MHD_DaemonInfoType
Values of this enum are used to specify what information about a
daemon is desired.
`MHD_DAEMON_INFO_KEY_SIZE'
Request information about the key size for a particular cipher
algorithm. The cipher algorithm should be passed as an extra
argument (of type 'enum MHD_GNUTLS_CipherAlgorithm'). No
longer supported, using this value will cause
MHD_get_daemon_info to return NULL.
`MHD_DAEMON_INFO_MAC_KEY_SIZE'
Request information about the key size for a particular cipher
algorithm. The cipher algorithm should be passed as an extra
argument (of type 'enum MHD_GNUTLS_HashAlgorithm'). No
longer supported, using this value will cause
MHD_get_daemon_info to return NULL.
`MHD_DAEMON_INFO_LISTEN_FD'
Request the file-descriptor number that MHD is using to
listen to the server socket. This can be useful if no port
was specified and a client needs to learn what port is
actually being used by MHD. No extra arguments should be
passed.
`MHD_DAEMON_INFO_EPOLL_FD_LINUX_ONLY'
Request the file-descriptor number that MHD is using for
epoll. If the build is not supporting epoll, NULL is
returned; if we are using a thread pool or this daemon was
not started with MHD_USE_EPOLL_LINUX_ONLY, (a pointer to) -1
is returned. If we are using MHD_USE_SELECT_INTERNALLY or
are in 'external' select mode, the internal epoll FD is
returned. This function must be used in external select mode
with epoll to obtain the FD to call epoll on. No extra
arguments should be passed.
File: libmicrohttpd.info, Node: microhttpd-info conn, Next: microhttpd-option conn, Prev: microhttpd-info daemon, Up: microhttpd-info
12.2 Obtaining state information about a connection
===================================================
-- Function: const union MHD_ConnectionInfo * MHD_get_connection_info
(struct MHD_Connection *daemon, enum MHD_ConnectionInfoType
infoType, ...)
Obtain information about the given connection.
CONNECTION
the connection about which information is desired;
INFOTYPE
type of information that is desired
...
additional arguments about the desired information (depending
on infoType)
Returns a union with the respective member (depending on infoType)
set to the desired information), or `NULL' in case the desired
information is not available or applicable.
-- Enumeration: MHD_ConnectionInfoType
Values of this enum are used to specify what information about a
connection is desired.
`MHD_CONNECTION_INFO_CIPHER_ALGO'
What cipher algorithm is being used (HTTPS connections only).
Takes no extra arguments. `NULL' is returned for non-HTTPS
connections.
`MHD_CONNECTION_INFO_PROTOCOL,'
Takes no extra arguments. Allows finding out the TLS/SSL
protocol used (HTTPS connections only). `NULL' is returned
for non-HTTPS connections.
`MHD_CONNECTION_INFO_CLIENT_ADDRESS'
Returns information about the address of the client. Returns
essentially a `struct sockaddr **' (since the API returns a
`union MHD_ConnectionInfo *' and that union contains a
`struct sockaddr *').
`MHD_CONNECTION_INFO_GNUTLS_SESSION,'
Takes no extra arguments. Allows access to the underlying
GNUtls session, including access to the underlying GNUtls
client certificate (HTTPS connections only). Takes no extra
arguments. `NULL' is returned for non-HTTPS connections.
`MHD_CONNECTION_INFO_GNUTLS_CLIENT_CERT,'
Dysfunctional (never implemented, deprecated). Use
MHD_CONNECTION_INFO_GNUTLS_SESSION to get the
`gnutls_session_t' and then call
`gnutls_certificate_get_peers()'.
`MHD_CONNECTION_INFO_DAEMON'
Returns information about `struct MHD_Daemon' which manages
this connection.
`MHD_CONNECTION_INFO_CONNECTION_FD'
Returns the file descriptor (usually a TCP socket) associated
with this connection (in the "connect-fd" member of the
returned struct). Note that manipulating the descriptor
directly can have problematic consequences (as in, break
HTTP). Applications might use this access to manipulate TCP
options, for example to set the "TCP-NODELAY" option for
COMET-like applications. Note that MHD will set TCP-CORK
after sending the HTTP header and clear it after finishing
the footers automatically (if the platform supports it). As
the connection callbacks are invoked in between, those might
be used to set different values for TCP-CORK and TCP-NODELAY
in the meantime.
File: libmicrohttpd.info, Node: microhttpd-option conn, Prev: microhttpd-info conn, Up: microhttpd-info
12.3 Setting custom options for an individual connection
========================================================
-- Function: int MHD_set_connection_option (struct MHD_Connection
*daemon, enum MHD_CONNECTION_OPTION option, ...)
Set a custom option for the given connection.
CONNECTION
the connection for which an option should be set or modified;
OPTION
option to set
...
additional arguments for the option (depending on option)
Returns `MHD_YES' on success, `MHD_NO' for errors (i.e. option
argument invalid or option unknown).
-- Enumeration: MHD_CONNECTION_OPTION
Values of this enum are used to specify which option for a
connection should be changed.
`MHD_CONNECTION_OPTION_TIMEOUT'
Set a custom timeout for the given connection. Specified as
the number of seconds, given as an `unsigned int'. Use zero
for no timeout.
File: libmicrohttpd.info, Node: GNU-LGPL, Next: GNU GPL with eCos Extension, Prev: microhttpd-info, Up: Top
GNU-LGPL
********
Version 2.1, February 1999
Copyright (C) 1991, 1999 Free Software Foundation, Inc.
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
[This is the first released version of the Lesser GPL. It also counts
as the successor of the GNU Library Public License, version 2, hence the
version number 2.1.]
Preamble
--------
The licenses for most software are designed to take away your freedom
to share and change it. By contrast, the GNU General Public Licenses
are intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users.
This license, the Lesser General Public License, applies to some
specially designated software--typically libraries--of the Free
Software Foundation and other authors who decide to use it. You can use
it too, but we suggest you first think carefully about whether this
license or the ordinary General Public License is the better strategy to
use in any particular case, based on the explanations below.
When we speak of free software, we are referring to freedom of use,
not price. Our General Public Licenses are designed to make sure that
you have the freedom to distribute copies of free software (and charge
for this service if you wish); that you receive source code or can get
it if you want it; that you can change the software and use pieces of it
in new free programs; and that you are informed that you can do these
things.
To protect your rights, we need to make restrictions that forbid
distributors to deny you these rights or to ask you to surrender these
rights. These restrictions translate to certain responsibilities for
you if you distribute copies of the library or if you modify it.
For example, if you distribute copies of the library, whether gratis
or for a fee, you must give the recipients all the rights that we gave
you. You must make sure that they, too, receive or can get the source
code. If you link other code with the library, you must provide
complete object files to the recipients, so that they can relink them
with the library after making changes to the library and recompiling
it. And you must show them these terms so they know their rights.
We protect your rights with a two-step method: (1) we copyright the
library, and (2) we offer you this license, which gives you legal
permission to copy, distribute and/or modify the library.
To protect each distributor, we want to make it very clear that
there is no warranty for the free library. Also, if the library is
modified by someone else and passed on, the recipients should know that
what they have is not the original version, so that the original
author's reputation will not be affected by problems that might be
introduced by others.
Finally, software patents pose a constant threat to the existence of
any free program. We wish to make sure that a company cannot
effectively restrict the users of a free program by obtaining a
restrictive license from a patent holder. Therefore, we insist that
any patent license obtained for a version of the library must be
consistent with the full freedom of use specified in this license.
Most GNU software, including some libraries, is covered by the
ordinary GNU General Public License. This license, the GNU Lesser
General Public License, applies to certain designated libraries, and is
quite different from the ordinary General Public License. We use this
license for certain libraries in order to permit linking those
libraries into non-free programs.
When a program is linked with a library, whether statically or using
a shared library, the combination of the two is legally speaking a
combined work, a derivative of the original library. The ordinary
General Public License therefore permits such linking only if the
entire combination fits its criteria of freedom. The Lesser General
Public License permits more lax criteria for linking other code with
the library.
We call this license the "Lesser" General Public License because it
does _Less_ to protect the user's freedom than the ordinary General
Public License. It also provides other free software developers Less
of an advantage over competing non-free programs. These disadvantages
are the reason we use the ordinary General Public License for many
libraries. However, the Lesser license provides advantages in certain
special circumstances.
For example, on rare occasions, there may be a special need to
encourage the widest possible use of a certain library, so that it
becomes a de-facto standard. To achieve this, non-free programs must be
allowed to use the library. A more frequent case is that a free
library does the same job as widely used non-free libraries. In this
case, there is little to gain by limiting the free library to free
software only, so we use the Lesser General Public License.
In other cases, permission to use a particular library in non-free
programs enables a greater number of people to use a large body of free
software. For example, permission to use the GNU C Library in non-free
programs enables many more people to use the whole GNU operating
system, as well as its variant, the GNU/Linux operating system.
Although the Lesser General Public License is Less protective of the
users' freedom, it does ensure that the user of a program that is
linked with the Library has the freedom and the wherewithal to run that
program using a modified version of the Library.
The precise terms and conditions for copying, distribution and
modification follow. Pay close attention to the difference between a
"work based on the library" and a "work that uses the library". The
former contains code derived from the library, whereas the latter must
be combined with the library in order to run.
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
---------------------------------------------------------------
0. This License Agreement applies to any software library or other
program which contains a notice placed by the copyright holder or
other authorized party saying it may be distributed under the
terms of this Lesser General Public License (also called "this
License"). Each licensee is addressed as "you".
A "library" means a collection of software functions and/or data
prepared so as to be conveniently linked with application programs
(which use some of those functions and data) to form executables.
The "Library", below, refers to any such software library or work
which has been distributed under these terms. A "work based on the
Library" means either the Library or any derivative work under
copyright law: that is to say, a work containing the Library or a
portion of it, either verbatim or with modifications and/or
translated straightforwardly into another language. (Hereinafter,
translation is included without limitation in the term
"modification".)
"Source code" for a work means the preferred form of the work for
making modifications to it. For a library, complete source code
means all the source code for all modules it contains, plus any
associated interface definition files, plus the scripts used to
control compilation and installation of the library.
Activities other than copying, distribution and modification are
not covered by this License; they are outside its scope. The act
of running a program using the Library is not restricted, and
output from such a program is covered only if its contents
constitute a work based on the Library (independent of the use of
the Library in a tool for writing it). Whether that is true
depends on what the Library does and what the program that uses
the Library does.
1. You may copy and distribute verbatim copies of the Library's
complete source code as you receive it, in any medium, provided
that you conspicuously and appropriately publish on each copy an
appropriate copyright notice and disclaimer of warranty; keep
intact all the notices that refer to this License and to the
absence of any warranty; and distribute a copy of this License
along with the Library.
You may charge a fee for the physical act of transferring a copy,
and you may at your option offer warranty protection in exchange
for a fee.
2. You may modify your copy or copies of the Library or any portion
of it, thus forming a work based on the Library, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:
a. The modified work must itself be a software library.
b. You must cause the files modified to carry prominent notices
stating that you changed the files and the date of any change.
c. You must cause the whole of the work to be licensed at no
charge to all third parties under the terms of this License.
d. If a facility in the modified Library refers to a function or
a table of data to be supplied by an application program that
uses the facility, other than as an argument passed when the
facility is invoked, then you must make a good faith effort
to ensure that, in the event an application does not supply
such function or table, the facility still operates, and
performs whatever part of its purpose remains meaningful.
(For example, a function in a library to compute square roots
has a purpose that is entirely well-defined independent of the
application. Therefore, Subsection 2d requires that any
application-supplied function or table used by this function
must be optional: if the application does not supply it, the
square root function must still compute square roots.)
These requirements apply to the modified work as a whole. If
identifiable sections of that work are not derived from the
Library, and can be reasonably considered independent and separate
works in themselves, then this License, and its terms, do not
apply to those sections when you distribute them as separate
works. But when you distribute the same sections as part of a
whole which is a work based on the Library, the distribution of
the whole must be on the terms of this License, whose permissions
for other licensees extend to the entire whole, and thus to each
and every part regardless of who wrote it.
Thus, it is not the intent of this section to claim rights or
contest your rights to work written entirely by you; rather, the
intent is to exercise the right to control the distribution of
derivative or collective works based on the Library.
In addition, mere aggregation of another work not based on the
Library with the Library (or with a work based on the Library) on
a volume of a storage or distribution medium does not bring the
other work under the scope of this License.
3. You may opt to apply the terms of the ordinary GNU General Public
License instead of this License to a given copy of the Library.
To do this, you must alter all the notices that refer to this
License, so that they refer to the ordinary GNU General Public
License, version 2, instead of to this License. (If a newer
version than version 2 of the ordinary GNU General Public License
has appeared, then you can specify that version instead if you
wish.) Do not make any other change in these notices.
Once this change is made in a given copy, it is irreversible for
that copy, so the ordinary GNU General Public License applies to
all subsequent copies and derivative works made from that copy.
This option is useful when you wish to copy part of the code of
the Library into a program that is not a library.
4. You may copy and distribute the Library (or a portion or
derivative of it, under Section 2) in object code or executable
form under the terms of Sections 1 and 2 above provided that you
accompany it with the complete corresponding machine-readable
source code, which must be distributed under the terms of Sections
1 and 2 above on a medium customarily used for software
interchange.
If distribution of object code is made by offering access to copy
from a designated place, then offering equivalent access to copy
the source code from the same place satisfies the requirement to
distribute the source code, even though third parties are not
compelled to copy the source along with the object code.
5. A program that contains no derivative of any portion of the
Library, but is designed to work with the Library by being
compiled or linked with it, is called a "work that uses the
Library". Such a work, in isolation, is not a derivative work of
the Library, and therefore falls outside the scope of this License.
However, linking a "work that uses the Library" with the Library
creates an executable that is a derivative of the Library (because
it contains portions of the Library), rather than a "work that
uses the library". The executable is therefore covered by this
License. Section 6 states terms for distribution of such
executables.
When a "work that uses the Library" uses material from a header
file that is part of the Library, the object code for the work may
be a derivative work of the Library even though the source code is
not. Whether this is true is especially significant if the work
can be linked without the Library, or if the work is itself a
library. The threshold for this to be true is not precisely
defined by law.
If such an object file uses only numerical parameters, data
structure layouts and accessors, and small macros and small inline
functions (ten lines or less in length), then the use of the object
file is unrestricted, regardless of whether it is legally a
derivative work. (Executables containing this object code plus
portions of the Library will still fall under Section 6.)
Otherwise, if the work is a derivative of the Library, you may
distribute the object code for the work under the terms of Section
6. Any executables containing that work also fall under Section 6,
whether or not they are linked directly with the Library itself.
6. As an exception to the Sections above, you may also combine or
link a "work that uses the Library" with the Library to produce a
work containing portions of the Library, and distribute that work
under terms of your choice, provided that the terms permit
modification of the work for the customer's own use and reverse
engineering for debugging such modifications.
You must give prominent notice with each copy of the work that the
Library is used in it and that the Library and its use are covered
by this License. You must supply a copy of this License. If the
work during execution displays copyright notices, you must include
the copyright notice for the Library among them, as well as a
reference directing the user to the copy of this License. Also,
you must do one of these things:
a. Accompany the work with the complete corresponding
machine-readable source code for the Library including
whatever changes were used in the work (which must be
distributed under Sections 1 and 2 above); and, if the work
is an executable linked with the Library, with the complete
machine-readable "work that uses the Library", as object code
and/or source code, so that the user can modify the Library
and then relink to produce a modified executable containing
the modified Library. (It is understood that the user who
changes the contents of definitions files in the Library will
not necessarily be able to recompile the application to use
the modified definitions.)
b. Use a suitable shared library mechanism for linking with the
Library. A suitable mechanism is one that (1) uses at run
time a copy of the library already present on the user's
computer system, rather than copying library functions into
the executable, and (2) will operate properly with a modified
version of the library, if the user installs one, as long as
the modified version is interface-compatible with the version
that the work was made with.
c. Accompany the work with a written offer, valid for at least
three years, to give the same user the materials specified in
Subsection 6a, above, for a charge no more than the cost of
performing this distribution.
d. If distribution of the work is made by offering access to copy
from a designated place, offer equivalent access to copy the
above specified materials from the same place.
e. Verify that the user has already received a copy of these
materials or that you have already sent this user a copy.
For an executable, the required form of the "work that uses the
Library" must include any data and utility programs needed for
reproducing the executable from it. However, as a special
exception, the materials to be distributed need not include
anything that is normally distributed (in either source or binary
form) with the major components (compiler, kernel, and so on) of
the operating system on which the executable runs, unless that
component itself accompanies the executable.
It may happen that this requirement contradicts the license
restrictions of other proprietary libraries that do not normally
accompany the operating system. Such a contradiction means you
cannot use both them and the Library together in an executable
that you distribute.
7. You may place library facilities that are a work based on the
Library side-by-side in a single library together with other
library facilities not covered by this License, and distribute
such a combined library, provided that the separate distribution
of the work based on the Library and of the other library
facilities is otherwise permitted, and provided that you do these
two things:
a. Accompany the combined library with a copy of the same work
based on the Library, uncombined with any other library
facilities. This must be distributed under the terms of the
Sections above.
b. Give prominent notice with the combined library of the fact
that part of it is a work based on the Library, and explaining
where to find the accompanying uncombined form of the same
work.
8. You may not copy, modify, sublicense, link with, or distribute the
Library except as expressly provided under this License. Any
attempt otherwise to copy, modify, sublicense, link with, or
distribute the Library is void, and will automatically terminate
your rights under this License. However, parties who have
received copies, or rights, from you under this License will not
have their licenses terminated so long as such parties remain in
full compliance.
9. You are not required to accept this License, since you have not
signed it. However, nothing else grants you permission to modify
or distribute the Library or its derivative works. These actions
are prohibited by law if you do not accept this License.
Therefore, by modifying or distributing the Library (or any work
based on the Library), you indicate your acceptance of this
License to do so, and all its terms and conditions for copying,
distributing or modifying the Library or works based on it.
10. Each time you redistribute the Library (or any work based on the
Library), the recipient automatically receives a license from the
original licensor to copy, distribute, link with or modify the
Library subject to these terms and conditions. You may not impose
any further restrictions on the recipients' exercise of the rights
granted herein. You are not responsible for enforcing compliance
by third parties with this License.
11. If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent
issues), conditions are imposed on you (whether by court order,
agreement or otherwise) that contradict the conditions of this
License, they do not excuse you from the conditions of this
License. If you cannot distribute so as to satisfy simultaneously
your obligations under this License and any other pertinent
obligations, then as a consequence you may not distribute the
Library at all. For example, if a patent license would not permit
royalty-free redistribution of the Library by all those who
receive copies directly or indirectly through you, then the only
way you could satisfy both it and this License would be to refrain
entirely from distribution of the Library.
If any portion of this section is held invalid or unenforceable
under any particular circumstance, the balance of the section is
intended to apply, and the section as a whole is intended to apply
in other circumstances.
It is not the purpose of this section to induce you to infringe any
patents or other property right claims or to contest validity of
any such claims; this section has the sole purpose of protecting
the integrity of the free software distribution system which is
implemented by public license practices. Many people have made
generous contributions to the wide range of software distributed
through that system in reliance on consistent application of that
system; it is up to the author/donor to decide if he or she is
willing to distribute software through any other system and a
licensee cannot impose that choice.
This section is intended to make thoroughly clear what is believed
to be a consequence of the rest of this License.
12. If the distribution and/or use of the Library is restricted in
certain countries either by patents or by copyrighted interfaces,
the original copyright holder who places the Library under this
License may add an explicit geographical distribution limitation
excluding those countries, so that distribution is permitted only
in or among countries not thus excluded. In such case, this
License incorporates the limitation as if written in the body of
this License.
13. The Free Software Foundation may publish revised and/or new
versions of the Lesser General Public License from time to time.
Such new versions will be similar in spirit to the present version,
but may differ in detail to address new problems or concerns.
Each version is given a distinguishing version number. If the
Library specifies a version number of this License which applies
to it and "any later version", you have the option of following
the terms and conditions either of that version or of any later
version published by the Free Software Foundation. If the Library
does not specify a license version number, you may choose any
version ever published by the Free Software Foundation.
14. If you wish to incorporate parts of the Library into other free
programs whose distribution conditions are incompatible with these,
write to the author to ask for permission. For software which is
copyrighted by the Free Software Foundation, write to the Free
Software Foundation; we sometimes make exceptions for this. Our
decision will be guided by the two goals of preserving the free
status of all derivatives of our free software and of promoting
the sharing and reuse of software generally.
NO WARRANTY
15. BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO
WARRANTY FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE
LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE LIBRARY "AS IS" WITHOUT
WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE
QUALITY AND PERFORMANCE OF THE LIBRARY IS WITH YOU. SHOULD THE
LIBRARY PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY
SERVICING, REPAIR OR CORRECTION.
16. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY
MODIFY AND/OR REDISTRIBUTE THE LIBRARY AS PERMITTED ABOVE, BE
LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL,
INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR
INABILITY TO USE THE LIBRARY (INCLUDING BUT NOT LIMITED TO LOSS OF
DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU
OR THIRD PARTIES OR A FAILURE OF THE LIBRARY TO OPERATE WITH ANY
OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN
ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
END OF TERMS AND CONDITIONS
---------------------------
How to Apply These Terms to Your New Libraries
----------------------------------------------
If you develop a new library, and you want it to be of the greatest
possible use to the public, we recommend making it free software that
everyone can redistribute and change. You can do so by permitting
redistribution under these terms (or, alternatively, under the terms of
the ordinary General Public License).
To apply these terms, attach the following notices to the library.
It is safest to attach them to the start of each source file to most
effectively convey the exclusion of warranty; and each file should have
at least the "copyright" line and a pointer to where the full notice is
found.
ONE LINE TO GIVE THE LIBRARY'S NAME AND AN IDEA OF WHAT IT DOES.
Copyright (C) YEAR NAME OF AUTHOR
This library is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or (at
your option) any later version.
This library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
USA.
Also add information on how to contact you by electronic and paper
mail.
You should also get your employer (if you work as a programmer) or
your school, if any, to sign a "copyright disclaimer" for the library,
if necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the library
`Frob' (a library for tweaking knobs) written by James Random Hacker.
SIGNATURE OF TY COON, 1 April 1990
Ty Coon, President of Vice
That's all there is to it!
File: libmicrohttpd.info, Node: GNU GPL with eCos Extension, Next: GNU-FDL, Prev: GNU-LGPL, Up: Top
GNU GPL with eCos Extension
***************************
Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc.
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
Preamble
--------
The licenses for most software are designed to take away your freedom
to share and change it. By contrast, the GNU General Public License is
intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users. This
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it. (Some other Free Software Foundation software is covered by
the GNU Library General Public License instead.) You can apply it to
your programs, too.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish), that you receive source code or can get it
if you want it, that you can change the software or use pieces of it in
new free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the rights.
These restrictions translate to certain responsibilities for you if you
distribute copies of the software, or if you modify it.
For example, if you distribute copies of such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have. You must make sure that they, too, receive or can get the
source code. And you must show them these terms so they know their
rights.
We protect your rights with two steps: (1) copyright the software,
and (2) offer you this license which gives you legal permission to copy,
distribute and/or modify the software.
Also, for each author's protection and ours, we want to make certain
that everyone understands that there is no warranty for this free
software. If the software is modified by someone else and passed on, we
want its recipients to know that what they have is not the original, so
that any problems introduced by others will not reflect on the original
authors' reputations.
Finally, any free program is threatened constantly by software
patents. We wish to avoid the danger that redistributors of a free
program will individually obtain patent licenses, in effect making the
program proprietary. To prevent this, we have made it clear that any
patent must be licensed for everyone's free use or not licensed at all.
The precise terms and conditions for copying, distribution and
modification follow.
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
1. This License applies to any program or other work which contains a
notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License. The "Program",
below, refers to any such program or work, and a "work based on
the Program" means either the Program or any derivative work under
copyright law: that is to say, a work containing the Program or a
portion of it, either verbatim or with modifications and/or
translated into another language. (Hereinafter, translation is
included without limitation in the term "modification".) Each
licensee is addressed as "you".
Activities other than copying, distribution and modification are
not covered by this License; they are outside its scope. The act
of running the Program is not restricted, and the output from the
Program is covered only if its contents constitute a work based on
the Program (independent of having been made by running the
Program). Whether that is true depends on what the Program does.
2. You may copy and distribute verbatim copies of the Program's
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the
notices that refer to this License and to the absence of any
warranty; and give any other recipients of the Program a copy of
this License along with the Program.
You may charge a fee for the physical act of transferring a copy,
and you may at your option offer warranty protection in exchange
for a fee.
3. You may modify your copy or copies of the Program or any portion
of it, thus forming a work based on the Program, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:
a. You must cause the modified files to carry prominent notices
stating that you changed the files and the date of any change.
b. You must cause any work that you distribute or publish, that
in whole or in part contains or is derived from the Program
or any part thereof, to be licensed as a whole at no charge
to all third parties under the terms of this License.
c. If the modified program normally reads commands interactively
when run, you must cause it, when started running for such
interactive use in the most ordinary way, to print or display
an announcement including an appropriate copyright notice and
a notice that there is no warranty (or else, saying that you
provide a warranty) and that users may redistribute the
program under these conditions, and telling the user how to
view a copy of this License. (Exception: if the Program
itself is interactive but does not normally print such an
announcement, your work based on the Program is not required
to print an announcement.)
These requirements apply to the modified work as a whole. If
identifiable sections of that work are not derived from the
Program, and can be reasonably considered independent and separate
works in themselves, then this License, and its terms, do not
apply to those sections when you distribute them as separate
works. But when you distribute the same sections as part of a
whole which is a work based on the Program, the distribution of
the whole must be on the terms of this License, whose permissions
for other licensees extend to the entire whole, and thus to each
and every part regardless of who wrote it.
Thus, it is not the intent of this section to claim rights or
contest your rights to work written entirely by you; rather, the
intent is to exercise the right to control the distribution of
derivative or collective works based on the Program.
In addition, mere aggregation of another work not based on the
Program with the Program (or with a work based on the Program) on
a volume of a storage or distribution medium does not bring the
other work under the scope of this License.
4. You may copy and distribute the Program (or a work based on it,
under Section 2) in object code or executable form under the terms
of Sections 1 and 2 above provided that you also do one of the
following:
a. Accompany it with the complete corresponding machine-readable
source code, which must be distributed under the terms of
Sections 1 and 2 above on a medium customarily used for
software interchange; or,
b. Accompany it with a written offer, valid for at least three
years, to give any third party, for a charge no more than your
cost of physically performing source distribution, a complete
machine-readable copy of the corresponding source code, to be
distributed under the terms of Sections 1 and 2 above on a
medium customarily used for software interchange; or,
c. Accompany it with the information you received as to the offer
to distribute corresponding source code. (This alternative is
allowed only for noncommercial distribution and only if you
received the program in object code or executable form with
such an offer, in accord with Subsection b above.)
The source code for a work means the preferred form of the work for
making modifications to it. For an executable work, complete
source code means all the source code for all modules it contains,
plus any associated interface definition files, plus the scripts
used to control compilation and installation of the executable.
However, as a special exception, the source code distributed need
not include anything that is normally distributed (in either
source or binary form) with the major components (compiler,
kernel, and so on) of the operating system on which the executable
runs, unless that component itself accompanies the executable.
If distribution of executable or object code is made by offering
access to copy from a designated place, then offering equivalent
access to copy the source code from the same place counts as
distribution of the source code, even though third parties are not
compelled to copy the source along with the object code.
5. You may not copy, modify, sublicense, or distribute the Program
except as expressly provided under this License. Any attempt
otherwise to copy, modify, sublicense or distribute the Program is
void, and will automatically terminate your rights under this
License. However, parties who have received copies, or rights,
from you under this License will not have their licenses
terminated so long as such parties remain in full compliance.
6. You are not required to accept this License, since you have not
signed it. However, nothing else grants you permission to modify
or distribute the Program or its derivative works. These actions
are prohibited by law if you do not accept this License.
Therefore, by modifying or distributing the Program (or any work
based on the Program), you indicate your acceptance of this
License to do so, and all its terms and conditions for copying,
distributing or modifying the Program or works based on it.
7. Each time you redistribute the Program (or any work based on the
Program), the recipient automatically receives a license from the
original licensor to copy, distribute or modify the Program
subject to these terms and conditions. You may not impose any
further restrictions on the recipients' exercise of the rights
granted herein. You are not responsible for enforcing compliance
by third parties to this License.
8. If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent
issues), conditions are imposed on you (whether by court order,
agreement or otherwise) that contradict the conditions of this
License, they do not excuse you from the conditions of this
License. If you cannot distribute so as to satisfy simultaneously
your obligations under this License and any other pertinent
obligations, then as a consequence you may not distribute the
Program at all. For example, if a patent license would not permit
royalty-free redistribution of the Program by all those who
receive copies directly or indirectly through you, then the only
way you could satisfy both it and this License would be to refrain
entirely from distribution of the Program.
If any portion of this section is held invalid or unenforceable
under any particular circumstance, the balance of the section is
intended to apply and the section as a whole is intended to apply
in other circumstances.
It is not the purpose of this section to induce you to infringe any
patents or other property right claims or to contest validity of
any such claims; this section has the sole purpose of protecting
the integrity of the free software distribution system, which is
implemented by public license practices. Many people have made
generous contributions to the wide range of software distributed
through that system in reliance on consistent application of that
system; it is up to the author/donor to decide if he or she is
willing to distribute software through any other system and a
licensee cannot impose that choice.
This section is intended to make thoroughly clear what is believed
to be a consequence of the rest of this License.
9. If the distribution and/or use of the Program is restricted in
certain countries either by patents or by copyrighted interfaces,
the original copyright holder who places the Program under this
License may add an explicit geographical distribution limitation
excluding those countries, so that distribution is permitted only
in or among countries not thus excluded. In such case, this
License incorporates the limitation as if written in the body of
this License.
10. The Free Software Foundation may publish revised and/or new
versions of the General Public License from time to time. Such
new versions will be similar in spirit to the present version, but
may differ in detail to address new problems or concerns.
Each version is given a distinguishing version number. If the
Program specifies a version number of this License which applies
to it and "any later version", you have the option of following
the terms and conditions either of that version or of any later
version published by the Free Software Foundation. If the Program
does not specify a version number of this License, you may choose
any version ever published by the Free Software Foundation.
11. If you wish to incorporate parts of the Program into other free
programs whose distribution conditions are different, write to the
author to ask for permission. For software which is copyrighted
by the Free Software Foundation, write to the Free Software
Foundation; we sometimes make exceptions for this. Our decision
will be guided by the two goals of preserving the free status of
all derivatives of our free software and of promoting the sharing
and reuse of software generally.
NO WARRANTY
12. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO
WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE
LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT
WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE
QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY
SERVICING, REPAIR OR CORRECTION.
13. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY
MODIFY AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE
LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL,
INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR
INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU
OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY
OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN
ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
ECOS EXTENSION
14. As a special exception, if other files instantiate templates or use
macros or inline functions from this file, or you compile this file
and link it with other works to produce a work based on this file,
this file does not by itself cause the resulting work to be
covered by the GNU General Public License. However the source code
for this file must still be made available in accordance with
section (3) of the GNU General Public License v2.
This exception does not invalidate any other reasons why a work
based on this file might be covered by the GNU General Public
License.
END OF TERMS AND CONDITIONS
---------------------------
How to Apply These Terms to Your New Programs
=============================================
If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these
terms.
To do so, attach the following notices to the program. It is safest
to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.
ONE LINE TO GIVE THE PROGRAM'S NAME AND AN IDEA OF WHAT IT DOES.
Copyright (C) 19YY NAME OF AUTHOR
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
Also add information on how to contact you by electronic and paper
mail.
If the program is interactive, make it output a short notice like
this when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) 19YY NAME OF AUTHOR
Gnomovision comes with ABSOLUTELY NO WARRANTY; for details
type `show w'. This is free software, and you are welcome
to redistribute it under certain conditions; type `show c'
for details.
The hypothetical commands `show w' and `show c' should show the
appropriate parts of the General Public License. Of course, the
commands you use may be called something other than `show w' and `show
c'; they could even be mouse-clicks or menu items--whatever suits your
program.
You should also get your employer (if you work as a programmer) or
your school, if any, to sign a "copyright disclaimer" for the program,
if necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright
interest in the program `Gnomovision'
(which makes passes at compilers) written
by James Hacker.
SIGNATURE OF TY COON, 1 April 1989
Ty Coon, President of Vice
This General Public License does not permit incorporating your
program into proprietary programs. If your program is a subroutine
library, you may consider it more useful to permit linking proprietary
applications with the library. If this is what you want to do, use the
GNU Library General Public License instead of this License.
File: libmicrohttpd.info, Node: GNU-FDL, Next: Concept Index, Prev: GNU GPL with eCos Extension, Up: Top
GNU-FDL
*******
Version 1.3, 3 November 2008
Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
`http://fsf.org/'
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
0. PREAMBLE
The purpose of this License is to make a manual, textbook, or other
functional and useful document "free" in the sense of freedom: to
assure everyone the effective freedom to copy and redistribute it,
with or without modifying it, either commercially or
noncommercially. Secondarily, this License preserves for the
author and publisher a way to get credit for their work, while not
being considered responsible for modifications made by others.
This License is a kind of "copyleft", which means that derivative
works of the document must themselves be free in the same sense.
It complements the GNU General Public License, which is a copyleft
license designed for free software.
We have designed this License in order to use it for manuals for
free software, because free software needs free documentation: a
free program should come with manuals providing the same freedoms
that the software does. But this License is not limited to
software manuals; it can be used for any textual work, regardless
of subject matter or whether it is published as a printed book.
We recommend this License principally for works whose purpose is
instruction or reference.
1. APPLICABILITY AND DEFINITIONS
This License applies to any manual or other work, in any medium,
that contains a notice placed by the copyright holder saying it
can be distributed under the terms of this License. Such a notice
grants a world-wide, royalty-free license, unlimited in duration,
to use that work under the conditions stated herein. The
"Document", below, refers to any such manual or work. Any member
of the public is a licensee, and is addressed as "you". You
accept the license if you copy, modify or distribute the work in a
way requiring permission under copyright law.
A "Modified Version" of the Document means any work containing the
Document or a portion of it, either copied verbatim, or with
modifications and/or translated into another language.
A "Secondary Section" is a named appendix or a front-matter section
of the Document that deals exclusively with the relationship of the
publishers or authors of the Document to the Document's overall
subject (or to related matters) and contains nothing that could
fall directly within that overall subject. (Thus, if the Document
is in part a textbook of mathematics, a Secondary Section may not
explain any mathematics.) The relationship could be a matter of
historical connection with the subject or with related matters, or
of legal, commercial, philosophical, ethical or political position
regarding them.
The "Invariant Sections" are certain Secondary Sections whose
titles are designated, as being those of Invariant Sections, in
the notice that says that the Document is released under this
License. If a section does not fit the above definition of
Secondary then it is not allowed to be designated as Invariant.
The Document may contain zero Invariant Sections. If the Document
does not identify any Invariant Sections then there are none.
The "Cover Texts" are certain short passages of text that are
listed, as Front-Cover Texts or Back-Cover Texts, in the notice
that says that the Document is released under this License. A
Front-Cover Text may be at most 5 words, and a Back-Cover Text may
be at most 25 words.
A "Transparent" copy of the Document means a machine-readable copy,
represented in a format whose specification is available to the
general public, that is suitable for revising the document
straightforwardly with generic text editors or (for images
composed of pixels) generic paint programs or (for drawings) some
widely available drawing editor, and that is suitable for input to
text formatters or for automatic translation to a variety of
formats suitable for input to text formatters. A copy made in an
otherwise Transparent file format whose markup, or absence of
markup, has been arranged to thwart or discourage subsequent
modification by readers is not Transparent. An image format is
not Transparent if used for any substantial amount of text. A
copy that is not "Transparent" is called "Opaque".
Examples of suitable formats for Transparent copies include plain
ASCII without markup, Texinfo input format, LaTeX input format,
SGML or XML using a publicly available DTD, and
standard-conforming simple HTML, PostScript or PDF designed for
human modification. Examples of transparent image formats include
PNG, XCF and JPG. Opaque formats include proprietary formats that
can be read and edited only by proprietary word processors, SGML or
XML for which the DTD and/or processing tools are not generally
available, and the machine-generated HTML, PostScript or PDF
produced by some word processors for output purposes only.
The "Title Page" means, for a printed book, the title page itself,
plus such following pages as are needed to hold, legibly, the
material this License requires to appear in the title page. For
works in formats which do not have any title page as such, "Title
Page" means the text near the most prominent appearance of the
work's title, preceding the beginning of the body of the text.
The "publisher" means any person or entity that distributes copies
of the Document to the public.
A section "Entitled XYZ" means a named subunit of the Document
whose title either is precisely XYZ or contains XYZ in parentheses
following text that translates XYZ in another language. (Here XYZ
stands for a specific section name mentioned below, such as
"Acknowledgements", "Dedications", "Endorsements", or "History".)
To "Preserve the Title" of such a section when you modify the
Document means that it remains a section "Entitled XYZ" according
to this definition.
The Document may include Warranty Disclaimers next to the notice
which states that this License applies to the Document. These
Warranty Disclaimers are considered to be included by reference in
this License, but only as regards disclaiming warranties: any other
implication that these Warranty Disclaimers may have is void and
has no effect on the meaning of this License.
2. VERBATIM COPYING
You may copy and distribute the Document in any medium, either
commercially or noncommercially, provided that this License, the
copyright notices, and the license notice saying this License
applies to the Document are reproduced in all copies, and that you
add no other conditions whatsoever to those of this License. You
may not use technical measures to obstruct or control the reading
or further copying of the copies you make or distribute. However,
you may accept compensation in exchange for copies. If you
distribute a large enough number of copies you must also follow
the conditions in section 3.
You may also lend copies, under the same conditions stated above,
and you may publicly display copies.
3. COPYING IN QUANTITY
If you publish printed copies (or copies in media that commonly
have printed covers) of the Document, numbering more than 100, and
the Document's license notice requires Cover Texts, you must
enclose the copies in covers that carry, clearly and legibly, all
these Cover Texts: Front-Cover Texts on the front cover, and
Back-Cover Texts on the back cover. Both covers must also clearly
and legibly identify you as the publisher of these copies. The
front cover must present the full title with all words of the
title equally prominent and visible. You may add other material
on the covers in addition. Copying with changes limited to the
covers, as long as they preserve the title of the Document and
satisfy these conditions, can be treated as verbatim copying in
other respects.
If the required texts for either cover are too voluminous to fit
legibly, you should put the first ones listed (as many as fit
reasonably) on the actual cover, and continue the rest onto
adjacent pages.
If you publish or distribute Opaque copies of the Document
numbering more than 100, you must either include a
machine-readable Transparent copy along with each Opaque copy, or
state in or with each Opaque copy a computer-network location from
which the general network-using public has access to download
using public-standard network protocols a complete Transparent
copy of the Document, free of added material. If you use the
latter option, you must take reasonably prudent steps, when you
begin distribution of Opaque copies in quantity, to ensure that
this Transparent copy will remain thus accessible at the stated
location until at least one year after the last time you
distribute an Opaque copy (directly or through your agents or
retailers) of that edition to the public.
It is requested, but not required, that you contact the authors of
the Document well before redistributing any large number of
copies, to give them a chance to provide you with an updated
version of the Document.
4. MODIFICATIONS
You may copy and distribute a Modified Version of the Document
under the conditions of sections 2 and 3 above, provided that you
release the Modified Version under precisely this License, with
the Modified Version filling the role of the Document, thus
licensing distribution and modification of the Modified Version to
whoever possesses a copy of it. In addition, you must do these
things in the Modified Version:
A. Use in the Title Page (and on the covers, if any) a title
distinct from that of the Document, and from those of
previous versions (which should, if there were any, be listed
in the History section of the Document). You may use the
same title as a previous version if the original publisher of
that version gives permission.
B. List on the Title Page, as authors, one or more persons or
entities responsible for authorship of the modifications in
the Modified Version, together with at least five of the
principal authors of the Document (all of its principal
authors, if it has fewer than five), unless they release you
from this requirement.
C. State on the Title page the name of the publisher of the
Modified Version, as the publisher.
D. Preserve all the copyright notices of the Document.
E. Add an appropriate copyright notice for your modifications
adjacent to the other copyright notices.
F. Include, immediately after the copyright notices, a license
notice giving the public permission to use the Modified
Version under the terms of this License, in the form shown in
the Addendum below.
G. Preserve in that license notice the full lists of Invariant
Sections and required Cover Texts given in the Document's
license notice.
H. Include an unaltered copy of this License.
I. Preserve the section Entitled "History", Preserve its Title,
and add to it an item stating at least the title, year, new
authors, and publisher of the Modified Version as given on
the Title Page. If there is no section Entitled "History" in
the Document, create one stating the title, year, authors,
and publisher of the Document as given on its Title Page,
then add an item describing the Modified Version as stated in
the previous sentence.
J. Preserve the network location, if any, given in the Document
for public access to a Transparent copy of the Document, and
likewise the network locations given in the Document for
previous versions it was based on. These may be placed in
the "History" section. You may omit a network location for a
work that was published at least four years before the
Document itself, or if the original publisher of the version
it refers to gives permission.
K. For any section Entitled "Acknowledgements" or "Dedications",
Preserve the Title of the section, and preserve in the
section all the substance and tone of each of the contributor
acknowledgements and/or dedications given therein.
L. Preserve all the Invariant Sections of the Document,
unaltered in their text and in their titles. Section numbers
or the equivalent are not considered part of the section
titles.
M. Delete any section Entitled "Endorsements". Such a section
may not be included in the Modified Version.
N. Do not retitle any existing section to be Entitled
"Endorsements" or to conflict in title with any Invariant
Section.
O. Preserve any Warranty Disclaimers.
If the Modified Version includes new front-matter sections or
appendices that qualify as Secondary Sections and contain no
material copied from the Document, you may at your option
designate some or all of these sections as invariant. To do this,
add their titles to the list of Invariant Sections in the Modified
Version's license notice. These titles must be distinct from any
other section titles.
You may add a section Entitled "Endorsements", provided it contains
nothing but endorsements of your Modified Version by various
parties--for example, statements of peer review or that the text
has been approved by an organization as the authoritative
definition of a standard.
You may add a passage of up to five words as a Front-Cover Text,
and a passage of up to 25 words as a Back-Cover Text, to the end
of the list of Cover Texts in the Modified Version. Only one
passage of Front-Cover Text and one of Back-Cover Text may be
added by (or through arrangements made by) any one entity. If the
Document already includes a cover text for the same cover,
previously added by you or by arrangement made by the same entity
you are acting on behalf of, you may not add another; but you may
replace the old one, on explicit permission from the previous
publisher that added the old one.
The author(s) and publisher(s) of the Document do not by this
License give permission to use their names for publicity for or to
assert or imply endorsement of any Modified Version.
5. COMBINING DOCUMENTS
You may combine the Document with other documents released under
this License, under the terms defined in section 4 above for
modified versions, provided that you include in the combination
all of the Invariant Sections of all of the original documents,
unmodified, and list them all as Invariant Sections of your
combined work in its license notice, and that you preserve all
their Warranty Disclaimers.
The combined work need only contain one copy of this License, and
multiple identical Invariant Sections may be replaced with a single
copy. If there are multiple Invariant Sections with the same name
but different contents, make the title of each such section unique
by adding at the end of it, in parentheses, the name of the
original author or publisher of that section if known, or else a
unique number. Make the same adjustment to the section titles in
the list of Invariant Sections in the license notice of the
combined work.
In the combination, you must combine any sections Entitled
"History" in the various original documents, forming one section
Entitled "History"; likewise combine any sections Entitled
"Acknowledgements", and any sections Entitled "Dedications". You
must delete all sections Entitled "Endorsements."
6. COLLECTIONS OF DOCUMENTS
You may make a collection consisting of the Document and other
documents released under this License, and replace the individual
copies of this License in the various documents with a single copy
that is included in the collection, provided that you follow the
rules of this License for verbatim copying of each of the
documents in all other respects.
You may extract a single document from such a collection, and
distribute it individually under this License, provided you insert
a copy of this License into the extracted document, and follow
this License in all other respects regarding verbatim copying of
that document.
7. AGGREGATION WITH INDEPENDENT WORKS
A compilation of the Document or its derivatives with other
separate and independent documents or works, in or on a volume of
a storage or distribution medium, is called an "aggregate" if the
copyright resulting from the compilation is not used to limit the
legal rights of the compilation's users beyond what the individual
works permit. When the Document is included in an aggregate, this
License does not apply to the other works in the aggregate which
are not themselves derivative works of the Document.
If the Cover Text requirement of section 3 is applicable to these
copies of the Document, then if the Document is less than one half
of the entire aggregate, the Document's Cover Texts may be placed
on covers that bracket the Document within the aggregate, or the
electronic equivalent of covers if the Document is in electronic
form. Otherwise they must appear on printed covers that bracket
the whole aggregate.
8. TRANSLATION
Translation is considered a kind of modification, so you may
distribute translations of the Document under the terms of section
4. Replacing Invariant Sections with translations requires special
permission from their copyright holders, but you may include
translations of some or all Invariant Sections in addition to the
original versions of these Invariant Sections. You may include a
translation of this License, and all the license notices in the
Document, and any Warranty Disclaimers, provided that you also
include the original English version of this License and the
original versions of those notices and disclaimers. In case of a
disagreement between the translation and the original version of
this License or a notice or disclaimer, the original version will
prevail.
If a section in the Document is Entitled "Acknowledgements",
"Dedications", or "History", the requirement (section 4) to
Preserve its Title (section 1) will typically require changing the
actual title.
9. TERMINATION
You may not copy, modify, sublicense, or distribute the Document
except as expressly provided under this License. Any attempt
otherwise to copy, modify, sublicense, or distribute it is void,
and will automatically terminate your rights under this License.
However, if you cease all violation of this License, then your
license from a particular copyright holder is reinstated (a)
provisionally, unless and until the copyright holder explicitly
and finally terminates your license, and (b) permanently, if the
copyright holder fails to notify you of the violation by some
reasonable means prior to 60 days after the cessation.
Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from
that copyright holder, and you cure the violation prior to 30 days
after your receipt of the notice.
Termination of your rights under this section does not terminate
the licenses of parties who have received copies or rights from
you under this License. If your rights have been terminated and
not permanently reinstated, receipt of a copy of some or all of
the same material does not give you any rights to use it.
10. FUTURE REVISIONS OF THIS LICENSE
The Free Software Foundation may publish new, revised versions of
the GNU Free Documentation License from time to time. Such new
versions will be similar in spirit to the present version, but may
differ in detail to address new problems or concerns. See
`http://www.gnu.org/copyleft/'.
Each version of the License is given a distinguishing version
number. If the Document specifies that a particular numbered
version of this License "or any later version" applies to it, you
have the option of following the terms and conditions either of
that specified version or of any later version that has been
published (not as a draft) by the Free Software Foundation. If
the Document does not specify a version number of this License,
you may choose any version ever published (not as a draft) by the
Free Software Foundation. If the Document specifies that a proxy
can decide which future versions of this License can be used, that
proxy's public statement of acceptance of a version permanently
authorizes you to choose that version for the Document.
11. RELICENSING
"Massive Multiauthor Collaboration Site" (or "MMC Site") means any
World Wide Web server that publishes copyrightable works and also
provides prominent facilities for anybody to edit those works. A
public wiki that anybody can edit is an example of such a server.
A "Massive Multiauthor Collaboration" (or "MMC") contained in the
site means any set of copyrightable works thus published on the MMC
site.
"CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0
license published by Creative Commons Corporation, a not-for-profit
corporation with a principal place of business in San Francisco,
California, as well as future copyleft versions of that license
published by that same organization.
"Incorporate" means to publish or republish a Document, in whole or
in part, as part of another Document.
An MMC is "eligible for relicensing" if it is licensed under this
License, and if all works that were first published under this
License somewhere other than this MMC, and subsequently
incorporated in whole or in part into the MMC, (1) had no cover
texts or invariant sections, and (2) were thus incorporated prior
to November 1, 2008.
The operator of an MMC Site may republish an MMC contained in the
site under CC-BY-SA on the same site at any time before August 1,
2009, provided the MMC is eligible for relicensing.
ADDENDUM: How to use this License for your documents
====================================================
To use this License in a document you have written, include a copy of
the License in the document and put the following copyright and license
notices just after the title page:
Copyright (C) YEAR YOUR NAME.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
Texts. A copy of the license is included in the section entitled ``GNU
Free Documentation License''.
If you have Invariant Sections, Front-Cover Texts and Back-Cover
Texts, replace the "with...Texts." line with this:
with the Invariant Sections being LIST THEIR TITLES, with
the Front-Cover Texts being LIST, and with the Back-Cover Texts
being LIST.
If you have Invariant Sections without Cover Texts, or some other
combination of the three, merge those two alternatives to suit the
situation.
If your document contains nontrivial examples of program code, we
recommend releasing these examples in parallel under your choice of
free software license, such as the GNU General Public License, to
permit their use in free software.
File: libmicrohttpd.info, Node: Concept Index, Next: Function and Data Index, Prev: GNU-FDL, Up: Top
Concept Index
*************
[index ]
* Menu:
* ARM: microhttpd-intro. (line 232)
* bind, restricting bind: microhttpd-const. (line 206)
* cipher: microhttpd-const. (line 269)
* clock: microhttpd-const. (line 88)
* compilation: microhttpd-intro. (line 112)
* connection, limiting number of connections: microhttpd-const.
(line 151)
* cookie: microhttpd-const. (line 436)
* cortex m3: microhttpd-intro. (line 232)
* date: microhttpd-const. (line 88)
* debugging: microhttpd-const. (line 24)
* DH: microhttpd-const. (line 405)
* digest auth: microhttpd-const. (line 292)
* eCos, GNU General Public License with eCos Extension: GNU GPL with eCos Extension.
(line 6)
* embedded systems <1>: microhttpd-const. (line 88)
* embedded systems: microhttpd-intro. (line 112)
* epoll <1>: microhttpd-info daemon.
(line 50)
* epoll <2>: microhttpd-const. (line 76)
* epoll: microhttpd-intro. (line 59)
* escaping: microhttpd-const. (line 373)
* FD_SETSIZE: microhttpd-const. (line 68)
* foreign-function interface: microhttpd-const. (line 351)
* GPL, GNU General Public License: GNU GPL with eCos Extension.
(line 6)
* IAR: microhttpd-intro. (line 232)
* internationalization: microhttpd-const. (line 373)
* IPv6: microhttpd-const. (line 43)
* license <1>: GNU-FDL. (line 6)
* license <2>: GNU GPL with eCos Extension.
(line 6)
* license: GNU-LGPL. (line 6)
* listen <1>: microhttpd-info daemon.
(line 43)
* listen: microhttpd-const. (line 95)
* logging: microhttpd-const. (line 217)
* long long: microhttpd-intro. (line 232)
* memory: microhttpd-const. (line 143)
* memory, limiting memory utilization: microhttpd-const. (line 135)
* MHD_LONG_LONG: microhttpd-intro. (line 232)
* microhttpd.h: microhttpd-intro. (line 172)
* options: microhttpd-const. (line 351)
* performance <1>: microhttpd-const. (line 343)
* performance: microhttpd-intro. (line 83)
* poll <1>: microhttpd-init. (line 75)
* poll <2>: microhttpd-const. (line 68)
* poll: microhttpd-intro. (line 59)
* portability: microhttpd-intro. (line 112)
* POST method <1>: microhttpd-post api. (line 6)
* POST method <2>: microhttpd-post. (line 6)
* POST method <3>: microhttpd-cb. (line 50)
* POST method <4>: microhttpd-struct. (line 19)
* POST method: microhttpd-const. (line 440)
* proxy: microhttpd-const. (line 95)
* pthread: microhttpd-const. (line 389)
* PUT method: microhttpd-cb. (line 50)
* query string: microhttpd-const. (line 217)
* quiesce <1>: microhttpd-init. (line 51)
* quiesce: microhttpd-const. (line 102)
* random: microhttpd-const. (line 292)
* replay attack: microhttpd-const. (line 303)
* select <1>: microhttpd-init. (line 75)
* select <2>: microhttpd-const. (line 68)
* select: microhttpd-intro. (line 59)
* signals: microhttpd-intro. (line 193)
* SNI: microhttpd-const. (line 277)
* SSL: microhttpd-const. (line 32)
* stack: microhttpd-const. (line 389)
* systemd: microhttpd-const. (line 325)
* thread: microhttpd-const. (line 389)
* timeout <1>: microhttpd-option conn.
(line 6)
* timeout <2>: microhttpd-inspect. (line 24)
* timeout: microhttpd-const. (line 179)
* TLS: microhttpd-const. (line 32)
File: libmicrohttpd.info, Node: Function and Data Index, Next: Type Index, Prev: Concept Index, Up: Top
Function and Data Index
***********************
[index ]
* Menu:
* *MHD_AcceptPolicyCallback: microhttpd-cb. (line 8)
* *MHD_AccessHandlerCallback: microhttpd-cb. (line 25)
* *MHD_ContentReaderCallback: microhttpd-cb. (line 133)
* *MHD_ContentReaderFreeCallback: microhttpd-cb. (line 179)
* *MHD_KeyValueIterator: microhttpd-cb. (line 110)
* *MHD_PostDataIterator: microhttpd-cb. (line 187)
* *MHD_RequestCompletedCallback: microhttpd-cb. (line 91)
* MHD_add_connection: microhttpd-init. (line 122)
* MHD_add_response_footer: microhttpd-response headers.
(line 20)
* MHD_add_response_header: microhttpd-response headers.
(line 8)
* MHD_basic_auth_get_username_password: microhttpd-dauth basic.
(line 8)
* MHD_create_post_processor: microhttpd-post api. (line 9)
* MHD_create_response_from_buffer: microhttpd-response create.
(line 93)
* MHD_create_response_from_callback: microhttpd-response create.
(line 9)
* MHD_create_response_from_data: microhttpd-response create.
(line 114)
* MHD_create_response_from_fd: microhttpd-response create.
(line 34)
* MHD_create_response_from_fd_at_offset: microhttpd-response create.
(line 53)
* MHD_del_response_header: microhttpd-response headers.
(line 37)
* MHD_destroy_post_processor: microhttpd-post api. (line 55)
* MHD_destroy_response: microhttpd-response enqueue.
(line 30)
* MHD_digest_auth_check: microhttpd-dauth digest.
(line 16)
* MHD_digest_auth_get_username: microhttpd-dauth digest.
(line 8)
* MHD_get_connection_info: microhttpd-info conn.
(line 9)
* MHD_get_connection_values: microhttpd-requests. (line 9)
* MHD_get_daemon_info: microhttpd-info daemon.
(line 8)
* MHD_get_fdset: microhttpd-inspect. (line 9)
* MHD_get_response_header: microhttpd-response inspect.
(line 20)
* MHD_get_response_headers: microhttpd-response inspect.
(line 8)
* MHD_get_timeout: microhttpd-inspect. (line 24)
* MHD_lookup_connection_value: microhttpd-requests. (line 59)
* MHD_post_process: microhttpd-post api. (line 35)
* MHD_queue_auth_fail_response: microhttpd-dauth digest.
(line 38)
* MHD_queue_basic_auth_fail_response: microhttpd-dauth basic.
(line 20)
* MHD_queue_response: microhttpd-response enqueue.
(line 9)
* MHD_quiesce_daemon: microhttpd-init. (line 51)
* MHD_resume_connection: microhttpd-flow. (line 51)
* MHD_run: microhttpd-init. (line 72)
* MHD_run_from_select: microhttpd-init. (line 90)
* MHD_set_connection_option: microhttpd-option conn.
(line 8)
* MHD_set_connection_value: microhttpd-requests. (line 36)
* MHD_set_panic_func: microhttpd-init. (line 7)
* MHD_start_daemon: microhttpd-init. (line 21)
* MHD_stop_daemon: microhttpd-init. (line 69)
* MHD_suspend_connection: microhttpd-flow. (line 22)
File: libmicrohttpd.info, Node: Type Index, Prev: Function and Data Index, Up: Top
Type Index
**********
[index ]
* Menu:
* MHD_Connection: microhttpd-struct. (line 10)
* MHD_CONNECTION_OPTION: microhttpd-option conn.
(line 23)
* MHD_ConnectionInfo: microhttpd-struct. (line 22)
* MHD_ConnectionInfoType: microhttpd-info conn.
(line 26)
* MHD_Daemon: microhttpd-struct. (line 7)
* MHD_DaemonInfo: microhttpd-struct. (line 25)
* MHD_DaemonInfoType: microhttpd-info daemon.
(line 26)
* MHD_FLAG: microhttpd-const. (line 7)
* MHD_OPTION: microhttpd-const. (line 127)
* MHD_OptionItem: microhttpd-const. (line 413)
* MHD_PostProcessor: microhttpd-struct. (line 19)
* MHD_RequestTerminationCode: microhttpd-const. (line 455)
* MHD_Response: microhttpd-struct. (line 16)
* MHD_ResponseMemoryMode: microhttpd-const. (line 474)
* MHD_ValueKind: microhttpd-const. (line 426)
Tag Table:
Node: Top816
Node: microhttpd-intro2975
Ref: fig:performance7014
Ref: tbl:supported7896
Node: microhttpd-const14024
Node: microhttpd-struct38339
Node: microhttpd-cb39119
Node: microhttpd-init47726
Node: microhttpd-inspect53476
Node: microhttpd-requests55396
Node: microhttpd-responses58879
Node: microhttpd-response enqueue59932
Ref: microhttpd-response enqueue-Footnote-162204
Node: microhttpd-response create62423
Node: microhttpd-response headers68423
Node: microhttpd-response inspect70251
Node: microhttpd-flow71422
Node: microhttpd-dauth74011
Node: microhttpd-dauth basic75557
Node: microhttpd-dauth digest76748
Node: microhttpd-post81394
Node: microhttpd-post api84337
Node: microhttpd-info86919
Node: microhttpd-info daemon87334
Node: microhttpd-info conn89991
Node: microhttpd-option conn93255
Node: GNU-LGPL94316
Node: GNU GPL with eCos Extension122435
Node: GNU-FDL142305
Node: Concept Index167410
Node: Function and Data Index173090
Node: Type Index177840
End Tag Table