1 hostip.c explained
2 ==================
3
4 The main COMPILE-TIME DEFINES to keep in mind when reading the host*.c
5 source file are these:
6
7 CURLRES_IPV6 - this host has getaddrinfo() and family, and thus we use
8 that. The host may not be able to resolve IPv6, but we don't really have to
9 take that into account. Hosts that aren't IPv6-enabled have CURLRES_IPV4
10 defined.
11
12 CURLRES_ARES - is defined if libcurl is built to use c-ares for asynchronous
13 name resolves. It cannot have ENABLE_IPV6 defined at the same time, as c-ares
14 has no ipv6 support. This can be Windows or *nix.
15
16 CURLRES_THREADED - is defined if libcurl is built to run under (native)
17 Windows, and then the name resolve will be done in a new thread, and the
18 supported asynch API will be the same as for ares-builds.
19
20 If any of the two previous are defined, CURLRES_ASYNCH is defined too. If
21 libcurl is not built to use an asynchronous resolver, CURLRES_SYNCH is
22 defined.
23
24 The host*.c sources files are split up like this:
25
26 hostip.c   - method-independent resolver functions and utility functions
27 hostasyn.c - functions for asynchronous name resolves
28 hostsyn.c  - functions for synchronous name resolves
29 hostares.c - functions for ares-using name resolves
30 hostthre.c - functions for threaded name resolves
31 hostip4.c  - ipv4-specific functions
32 hostip6.c  - ipv6-specific functions
33
34 The hostip.h is the single united header file for all this. It defines the
35 CURLRES_* defines based on the config*.h and setup.h defines.
36