This function sets a callback that is invoked after the socket is
created, but before the connection is established. This is an ideal
time to customize various socket options.
Add user-visible entrypoints ares_{get,set}_servers_ports(3), which
take struct ares_addr_port_node rather than struct ares_addr_node.
This structure includes a UDP and TCP port number; if this is set
to zero, the channel-wide port values are used as before.
Similarly, add a new ares_set_servers_ports_csv(3) entrypoint, which
is analogous to ares_set_servers(3) except it doesn't ignore any
specified port information; instead, any per-server specified port
is used as both the UDP and TCP port for that server.
The internal struct ares_addr is extended to hold the UDP/TCP ports,
stored in network order, with the convention that a value of zero
indicates that the channel-wide UDP/TCP port should be used.
For the internal implementation of ares_dup(3), shift to use the
_ports() version of the get/set functions, so port information is
transferred correctly to the new channel.
Update manpages, and add missing ares_set_servers_csv to the lists
while we're at it
Add a new ares_library_init_mem() initialization function for the
library which allows the library user to specify their own malloc,
realloc & free equivalents for use library-wide.
Store these function pointers in library-wide global variables,
defaulting to libc's malloc(), realloc() and free().
Change all calls to malloc, realloc and free to use the function pointer
instead. Also ensure that ares_strdup() is always available
(even if the local environment includes strdup(3)), and change the
library code to always use it.
Convert calls to calloc() to use ares_malloc() + memset
Add 3 new functions to set the local binding for the out-going
socket connection, and add ares_set_servers_csv() to set a
list of servers at once as a comma-separated string.
Signed-off-by: Ben Greear <greearb@candelatech.com>
that is now used by the ares_parse_*_reply() functions instead of the
ares_expand_name() simply to easier return ARES_EBADRESP for the cases where
the name expansion fails as in responses that really isn't expected.
in man resolv.conf:
causes round robin selection of nameservers from among those listed. This
has the effect of spreading the query load among all listed servers, rather
than having all clients try the first listed server first every time.
You can enable it with ARES_OPT_ROTATE
outstanding queries, and processing a DNS response packet was O(n) in the
number of outstanding queries. To speed things up in Google, we added a few circular,
doubly-linked lists of queries that are hash-bucketed based on
the attributes we care about, so most important operations are now O(1).
It might be that the number of buckets are higher than most people would need,
but on a quick calculation it should only be 100kB or so even on a 64-bit
system, so I've let it stay as-is.
Andrew Ayer
David Drysdale
Daniel Stenberg
Yang Tse
hpopescu@ixiacom.com
David Stuart
Guenter Knauf
Ben Greear
Gisle Vanem
Steinar H. Gunderson