The reSIProcate Utility Library (rutil)

rutil holds the general-purpose code that the SIP stack, the Dialog Usage Manager and the other reSIProcate libraries are built on.

Very little of it is SIP-specific; for SIP, see The reSIProcate SIP Stack library (resip) and The Dialog Usage Manager library (dum).

Strings and Parsing

• resip::Data is reSIProcate's string and byte-buffer class, used in place of std::string throughout the libraries. It can share or borrow buffers instead of copying them, and has helpers for hex, base64, URL and XML encoding, and number conversion.
• resip::ParseBuffer is a bounds-checked cursor over a buffer, used by all of the parsers.
• resip::Inserter streams any container whose elements have operator<<.

Threads and Queues

• resip::Mutex, resip::RecursiveMutex, resip::Lock and resip::Condition are now typedefs of std::mutex, std::recursive_mutex, std::unique_lock and std::condition_variable; resip::RWMutex, resip::ReadLock and resip::WriteLock provide reader/writer locking.
• resip::ThreadIf wraps a std::thread with run(), shutdown() and join(). It is kept for existing code; new code should use std::thread directly.
• resip::Fifo and resip::TimeLimitFifo are the thread-safe message queues that the libraries use to pass messages between threads.

Sockets and Event Loops

• resip::FdPollGrp waits for socket events using epoll, poll() (WSAPoll() on Windows) or select(); resip::FdPollItemIf is the interface for a socket registered with it.
• resip::SelectInterruptor wakes up a thread that is blocked waiting for socket events.
• resip::GenericIPAddress, resip::DnsUtil and the cross-platform socket functions in Socket.hxx handle IPv4 and IPv6 addresses and sockets.

DNS

The asynchronous DNS resolver used by the SIP stack lives in rutil/dns. resip::DnsStub caches results and runs queries for A, AAAA, SRV, NAPTR and CNAME records; it talks to the network through the resip::ExternalDns interface, which resip::AresDns implements using either c-ares or the bundled copy of ares.

Logging

resip::Log is configured with resip::Log::initialize(), which can log to the console, syslog, a file or an application-supplied resip::ExternalLogger, with per-thread and per-subsystem levels. Code logs through the StackLog, DebugLog, InfoLog, WarningLog, ErrLog and CritLog macros in Logger.hxx, each tagged with a resip::Subsystem.

Other Utilities

• resip::Timer: millisecond and microsecond clocks and the SIP T1, T2 and T4 timer values.
• resip::Random: pseudo-random and cryptographically secure random values, in raw, hex and base64 form.
• resip::ConfigParse: reads the command line and name = value configuration files used by repro, reTurn and the other servers.
• resip::ServerProcess: daemonizing, PID files, signal handling and dropping privileges for those servers.
• resip::DigestStream: computes MD5 and SHA digests through a std::ostream.
• resip::OpenSSLInit: one-time OpenSSL setup, when built with OpenSSL.
• resip::HepAgent: sends copies of SIP and RTCP traffic to a HEP (Homer) capture server.