Rich Felker
d1395c43c0
the specification for freeaddrinfo allows it to be used to free "arbitrary sublists" of the list returned by getaddrinfo. it's not clearly stated how such sublists come into existence, but the interpretation seems to be that the application can edit the ai_next pointers to cut off a portion of the list and then free it. actual freeing of individual list slots is contrary to the design of our getaddrinfo implementation, which has no failure paths after making a single allocation, so that light callers can avoid linking realloc/free. freeing individual slots is also incompatible with sharing the string for ai_canonname, which the current implementation does despite no requirement that it be present except on the first result. so, rather than actually freeing individual slots, provide a way to find the start of the allocated array, and reference-count it, freeing the memory all at once after the last slot has been freed. since the language in the spec is "arbitrary sublists", no provision for handling other constructs like multiple lists glued together, circular links, etc. is made. presumably passing such a construct to freeaddrinfo produces undefined behavior.
musl libc
musl, pronounced like the word "mussel", is an MIT-licensed
implementation of the standard C library targetting the Linux syscall
API, suitable for use in a wide range of deployment environments. musl
offers efficient static and dynamic linking support, lightweight code
and low runtime overhead, strong fail-safe guarantees under correct
usage, and correctness in the sense of standards conformance and
safety. musl is built on the principle that these goals are best
achieved through simple code that is easy to understand and maintain.
The 1.1 release series for musl features coverage for all interfaces
defined in ISO C99 and POSIX 2008 base, along with a number of
non-standardized interfaces for compatibility with Linux, BSD, and
glibc functionality.
For basic installation instructions, see the included INSTALL file.
Information on full musl-targeted compiler toolchains, system
bootstrapping, and Linux distributions built on musl can be found on
the project website:
http://www.musl-libc.org/