allow "0" as service name for raw sockets.

ok sthen@ bluhm@

accept and use any protocol specified by the caller.

issue spotted by naddy@

Only use the search domains for DNS lookups, as the current resolver does.
Better not diverge too much in behavior at this point.
Typo fix and doc update while there.

knf

make separate structures for pack and unpack

include yp headers if necessary.
remove unused variable.

Get rid of the hostaddr_async subquery and merge its behaviour
directly into getaddrinfo_async_run. Simplifies everything by
a great deal.

Make hostaddr_async() return a linked list of struct addrinfo. First
round of a getaddrinfo_async() simplification. The goal is to make YP
support easier to add, and eventually remove the whole host

Make hostaddr_async() return a linked list of struct addrinfo. First
round of a getaddrinfo_async() simplification. The goal is to make YP
support easier to add, and eventually remove the whole hostaddr_async
subquery.

show more ...

Improve error reporting in getnameinfo_async() and getaddrinfo_async().
They do not have to deal with h_errno at all. Also, errno is only kept
for EAI_SYSTEM. Small code cleanup while there.

Adapt

Improve error reporting in getnameinfo_async() and getaddrinfo_async().
They do not have to deal with h_errno at all. Also, errno is only kept
for EAI_SYSTEM. Small code cleanup while there.

Adapt getnameinfo() and getaddrinfo() wrappers to correctly save errno
and overwrite it in the EAI_SYSTEM case.

General errno handling issue reported by mikeb@.

show more ...

properly report EAI_SERVICE when the given servname is not defined for
the given protocol.

Better handling of servname in getaddrinfo_async. Do not necessarily
fail if there is no entry for a given protocol. Fix issue reported by
early testers.

fix a few warnings

Import asr, an experimental async resolver implementation.
The idea is to eventually replace the existing resolver with
something better. Time to start working on it in tree.

ok deraadt@