libre  0.5.0
libre Development Documentation

Development documentation for libre

libre README
============
libre is a Generic library for real-time communications with async IO support.
Copyright (C) 2010 - 2016 Creytiv.com
[![Build Status](https://travis-ci.org/creytiv/re.svg?branch=master)](https://travis-ci.org/creytiv/re)
## Features
* SIP Stack ([RFC 3261](https://tools.ietf.org/html/rfc3261))
* SDP
* RTP and RTCP
* SRTP and SRTCP (Secure RTP)
* DNS-Client
* STUN/TURN/ICE stack
* BFCP
* HTTP-stack with client/server
* Websockets
* Jitter-buffer
* Async I/O (poll, epoll, select, kqueue)
* UDP/TCP/TLS/DTLS transport
* JSON parser
## Building
libre is using GNU makefiles, and OpenSSL development headers must be
installed before building.
### Build with debug enabled
```
$ make
$ sudo make install
$ sudo ldconfig
```
### Build with release
```
$ make RELEASE=1
$ sudo make RELEASE=1 install
$ sudo ldconfig
```
### Build with clang compiler
```
$ make CC=clang
$ sudo make CC=clang install
$ sudo ldconfig
```
## Documentation
The online documentation generated with doxygen is available in
the main [website](http://creytiv.com/doxygen/re-dox/html/)
### Examples
Coding examples are available from the
[redemo](http://creytiv.com/pub/redemo-0.4.1.tar.gz) project
## License
The libre project is using the BSD license.
## Contributing
Patches can sent via Github
[Pull-Requests](https://github.com/creytiv/re/pulls) or to the RE devel
[mailing-list](http://lists.creytiv.com/mailman/listinfo/re-devel).
Currently we only accept small patches.
Please send private feedback to libre [at] creytiv.com
## Design goals
* Portable POSIX source code (ANSI C89 and ISO C99 standard)
* Robust, fast, low memory footprint
* RFC compliance
* IPv4 and IPv6 support
## Modules
| Name | Status | Description |
|----------|----------|------------------------------------------------|
| aes | unstable | AES (Advanced Encryption Standard) |
| base64 | testing | Base-64 encoding/decoding functions |
| bfcp | unstable | The Binary Floor Control Protocol (BFCP) |
| conf | testing | Configuration file parser |
| crc32 | testing | 32-bit CRC defined in ITU V.42 |
| dbg | testing | Debug printing |
| dns | stable | DNS resolving (NAPTR, SRV, A) |
| fmt | testing | Formatted printing and regular expression |
| hash | testing | Hashmap table |
| hmac | testing | HMAC: Keyed-Hashing for Message Authentication |
| http | unstable | HTTP parser (RFC 2616) |
| httpauth | testing | HTTP-based Authentication (RFC 2617) |
| ice | unstable | Interactive Connectivity Establishment (ICE) |
| jbuf | testing | Jitter buffer |
| json | unstable | JavaScript Object Notation (JSON) |
| list | stable | Sortable doubly-linked list handling |
| lock | testing | Resource locking functions |
| main | testing | Main poll loop |
| mbuf | stable | Linear memory buffers |
| md5 | stable | The MD5 Message-Digest Algorithm (RFC 1321) |
| mem | stable | Memory referencing |
| mod | testing | Run-time module loading |
| mqueue | testing | Thread-safe message queue |
| msg | unstable | Generic message component library |
| natbd | unstable | NAT Behavior Discovery using STUN |
| net | testing | Networking routines |
| odict | unstable | Ordered Dictionary |
| rtp | testing | Real-time Transport Protocol |
| sa | stable | Socket Address functions |
| sdp | testing | Session Description Protocol |
| sha | testing | Secure Hash Standard, NIST, FIPS PUB 180-1 |
| sip | stable | Core SIP library |
| sipevent | testing | SIP Event framework |
| sipreg | stable | SIP register client |
| sipsess | stable | SIP Sessions |
| srtp | unstable | Secure Real-time Transport Protocol (SRTP) |
| stun | stable | Session Traversal Utilities for NAT (STUN) |
| sys | testing | System information |
| tcp | testing | TCP transport |
| telev | testing | Telephony Events (RFC 4733) |
| tls | unstable | Transport Layer Security |
| tmr | stable | Timer handling |
| turn | stable | Obtaining Relay Addresses from STUN (TURN) |
| udp | testing | UDP transport |
| uri | testing | Generic URI library |
| websock | unstable | WebSocket Client and Server |
legend:
* *stable* - code complete; stable code and stable API
* *testing* - code complete, but API might change
* *unstable* - code complete but not completely tested
* *development* - code is under development
## Features
* [RFC 1321](https://tools.ietf.org/html/rfc1321) - The MD5 Message-Digest Algorithm
* [RFC 1886](https://tools.ietf.org/html/rfc1886) - DNS Extensions to support IP version 6
* [RFC 2032](https://tools.ietf.org/html/rfc2032) - RTP Payload Format for H.261 Video Streams
* [RFC 2616](https://tools.ietf.org/html/rfc2616) - Hypertext Transfer Protocol -- HTTP/1.1
* [RFC 2617](https://tools.ietf.org/html/rfc2617) - HTTP Authentication: Basic and Digest Access Authentication
* [RFC 2782](https://tools.ietf.org/html/rfc2782) - A DNS RR for Specifying the Location of Services (DNS SRV)
* [RFC 2915](https://tools.ietf.org/html/rfc2915) - The Naming Authority Pointer (NAPTR) DNS Resource Record
* [RFC 3261](https://tools.ietf.org/html/rfc3261) - SIP: Session Initiation Protocol
* [RFC 3263](https://tools.ietf.org/html/rfc3263) - Locating SIP Servers
* [RFC 3264](https://tools.ietf.org/html/rfc3264) - An Offer/Answer Model with SDP
* [RFC 3265](https://tools.ietf.org/html/rfc3265) - SIP-Specific Event Notification
* [RFC 3327](https://tools.ietf.org/html/rfc3327) - SIP Extension Header Field for Registering Non-Adjacent Contacts
* [RFC 3428](https://tools.ietf.org/html/rfc3428) - SIP Extension for Instant Messaging
* [RFC 3489](https://tools.ietf.org/html/rfc3489) - STUN - Simple Traversal of UDP Through NATs
* [RFC 3515](https://tools.ietf.org/html/rfc3515) - The SIP Refer Method
* [RFC 3550](https://tools.ietf.org/html/rfc3550) - RTP: A Transport Protocol for Real-Time Applications
* [RFC 3551](https://tools.ietf.org/html/rfc3551) - RTP Profile for Audio and Video Conferences with Minimal Control
* [RFC 3555](https://tools.ietf.org/html/rfc3555) - MIME Type Registration of RTP Payload Formats
* [RFC 3556](https://tools.ietf.org/html/rfc3556) - SDP Bandwidth Modifiers for RTCP Bandwidth
* [RFC 3581](https://tools.ietf.org/html/rfc3581) - An Extension to SIP for Symmetric Response Routing
* [RFC 3605](https://tools.ietf.org/html/rfc3605) - RTCP attribute in SDP
* [RFC 3711](https://tools.ietf.org/html/rfc3711) - The Secure Real-time Transport Protocol (SRTP)
* [RFC 3969](https://tools.ietf.org/html/rfc3969) - The IANA URI Parameter Registry for SIP
* [RFC 3994](https://tools.ietf.org/html/rfc3994) - Indication of Message Composition for Instant Messaging
* [RFC 4346](https://tools.ietf.org/html/rfc4346) - The TLS Protocol Version 1.1
* [RFC 4566](https://tools.ietf.org/html/rfc4566) - SDP: Session Description Protocol
* [RFC 4582](https://tools.ietf.org/html/rfc4582) - The Binary Floor Control Protocol (BFCP)
* [RFC 4582bis](https://tools.ietf.org/html/draft-ietf-bfcpbis-rfc4582bis-08) - The Binary Floor Control Protocol (BFCP)
* [RFC 4585](https://tools.ietf.org/html/rfc4585) - Extended RTP Profile for RTCP-Based Feedback
* [RFC 4733](https://tools.ietf.org/html/rfc4733) - RTP Payload for DTMF Digits, Telephony Tones, and Teleph. Signals
* [RFC 4961](https://tools.ietf.org/html/rfc4961) - Symmetric RTP / RTP Control Protocol (RTCP)
* [RFC 5118](https://tools.ietf.org/html/rfc5118) - SIP Torture Test Messages for IPv6
* [RFC 5245](https://tools.ietf.org/html/rfc5245) - Interactive Connectivity Establishment (ICE)
* [RFC 5389](https://tools.ietf.org/html/rfc5389) - Session Traversal Utilities for NAT (STUN)
* [RFC 5626](https://tools.ietf.org/html/rfc5626) - Managing Client-Initiated Connections in SIP
* [RFC 5761](https://tools.ietf.org/html/rfc5761) - Multiplexing RTP Data and Control Packets on a Single Port
* [RFC 5766](https://tools.ietf.org/html/rfc5766) - Traversal Using Relays around NAT (TURN)
* [RFC 5768](https://tools.ietf.org/html/rfc5768) - Indicating Support for ICE in SIP
* [RFC 5769](https://tools.ietf.org/html/rfc5769) - Test vectors for STUN
* [RFC 5780](https://tools.ietf.org/html/rfc5780) - NAT Behaviour Discovery Using STUN
* [RFC 6026](https://tools.ietf.org/html/rfc6026) - Correct Transaction Handling for 2xx Resp. to SIP INVITE Requests
* [RFC 6156](https://tools.ietf.org/html/rfc6156) - TURN Extension for IPv6
* [RFC 6188](https://tools.ietf.org/html/rfc6188) - The Use of AES-192 and AES-256 in Secure RTP
* [RFC 6455](https://tools.ietf.org/html/rfc6455) - The WebSocket Protocol
* [RFC 7159](https://tools.ietf.org/html/rfc7159) - JavaScript Object Notation (JSON)
* [RFC 7350](https://tools.ietf.org/html/rfc7350) - DTLS as Transport for STUN
## Supported platforms
* Linux
* FreeBSD
* OpenBSD
* NetBSD
* Solaris
* Windows
* Apple Mac OS X and iOS
* Android
### Supported versions of C Standard library
* Android bionic
* BSD libc
* GNU C Library (glibc)
* Windows C Run-Time Libraries (CRT)
* uClibc
### Supported compilers:
* gcc 3.x
* gcc 4.x
* gcc 5.x
* gcc 6.x
* ms vc2003 compiler
* clang
### Supported versions of OpenSSL
* OpenSSL version 1.0.1
* OpenSSL version 1.0.2
* OpenSSL version 1.1.0 (supported since version 0.5.0)
* LibreSSL version 2.x
## Coding guidelines
* Use enum for constants where appropriate
* Use const as much as possible (where appropriate)
* Use C99 data types (intN_t, uintN_t, bool)
* Hide data-types in .c files where possible (use struct foo)
* Avoid malloc/free, use mem_alloc/mem_deref instead
* CVS/svn/git tags are NOT allowed in the code!
* Avoid bit-fields in structs which are not portable
* Use dummy handlers for timing-critical callbacks
* return err, return alloced objects as pointer-pointers
* in allocating functions, first arg is always double pointer
* Use POSIX error-codes; EINVAL for invalid args, EBADMSG for
parse errors and EPROTO for protocol errors
## Transport protocols
| | TCP | UDP | TLS | DTLS|
|:--------|:---:|:---:|:---:|:---:|
| BFCP | - | yes | - | - |
| DNS | yes | yes | - | - |
| HTTP | yes | n/a | yes | n/a |
| ICE | - | yes | - | - |
| RTP | - | yes | - | - |
| RTCP | - | yes | - | - |
| SIP | yes | yes | yes | - |
| STUN | yes | yes | yes | yes |
| TURN | yes | yes | yes | yes |
| WEBSOCK | yes | n/a | yes | n/a |
## Related projects
* [librem](https://github.com/creytiv/rem)
* [retest](https://github.com/creytiv/retest)
* [baresip](https://github.com/alfredh/baresip)
* [restund](http://creytiv.com/restund.html)
## References
http://creytiv.com/re.html
https://github.com/creytiv/re
http://lists.creytiv.com/mailman/listinfo/re-devel

modules