hostip.c explained | |
================== | |
The main COMPILE-TIME DEFINES to keep in mind when reading the host*.c | |
source file are these: | |
CURLRES_IPV6 - this host has getaddrinfo() and family, and thus we use | |
that. The host may not be able to resolve IPv6, but we don't really have to | |
take that into account. Hosts that aren't IPv6-enabled have CURLRES_IPV4 | |
defined. | |
CURLRES_ARES - is defined if libcurl is built to use c-ares for asynchronous | |
name resolves. It cannot have ENABLE_IPV6 defined at the same time, as c-ares | |
has no ipv6 support. This can be Windows or *nix. | |
CURLRES_THREADED - is defined if libcurl is built to run under (native) | |
Windows, and then the name resolve will be done in a new thread, and the | |
supported asynch API will be the same as for ares-builds. | |
If any of the two previous are defined, CURLRES_ASYNCH is defined too. If | |
libcurl is not built to use an asynchronous resolver, CURLRES_SYNCH is | |
defined. | |
The host*.c sources files are split up like this: | |
hostip.c - method-independent resolver functions and utility functions | |
hostasyn.c - functions for asynchronous name resolves | |
hostsyn.c - functions for synchronous name resolves | |
hostares.c - functions for ares-using name resolves | |
hostthre.c - functions for threaded name resolves | |
hostip4.c - ipv4-specific functions | |
hostip6.c - ipv6-specific functions | |
The hostip.h is the single united header file for all this. It defines the | |
CURLRES_* defines based on the config*.h and setup.h defines. |