In some cases, on error errinfo->err may hold an alocated error message.
Free it on an error condition.

Signed-off-by: Simo Sorce <simo@redhat.com>

glibc does not declare a number of common, useful extensions such as
asprintf unless _GNU_SOURCE is defined.  Define it early in the
configure process so that it is available for autoconf tests.

Defining _GNU_SOURCE unfortunately causes glibc to use the non-POSIX
version of strerror_r, which we now handle using the k5-platform.h
wrapper.

ticket: 7961

Include autoconf.h (either directly or via proxy) before system
headers, so that feature test macros defined there can affect the
system namespace.  Where include order was changed, eliminate some
redundant or unnecessary includes.

ticket: 7961

Take advantage of the strerror_r portability wrapper to simplify code
using it.  Remove unused macros related to strerror_r in
ldap_service_stash.c and plugins.c.

ticket: 7961

On systems where strerror_r is not the POSIX version, define it to
k5_strerror_r.  Implement k5_strerror_r in libkrb5support using
strerror_s, strerror, or the GNU strerror_r as appropriate.

ticket: 7961

Remove code to set or reference the length fields of socket addresses
(sa_len/sin_len/sin6_len), since they aren't portable and setting them
is not required.  Remove autoconf tests for those fields which are no
longer used or which were never used.

There is one exception: in localaddr.c, we still neeed to reference
sa_len for the definition of ifreq_size on platforms which have
sa_len.  Leave that behind, along with the autoconf test which defines
SA_LEN.

In socket-utils.h, replace the socklen macro with an inline function
sa_socklen which always uses the address family, even on platforms
with the sa_len sockaddr field.  This removes the need to set sa_len
in socket addresses we construct.

In setup_udp_port_1, remove the haddrbuf parameter and use paddr like
we already do for one of the log messages.  In setup_udp_port, remove
the long switch statement and just look for AF_INET/AF_INET6
addresses.  Split up udp_flags into two booleans for clarity.  Update
the comment in loop_setup_network since we did the "To do" item a long
time ago.

For example, FreeBSD has removed RTM_OLDADD and RTM_OLDDEL from its API
in March 2014, with the message:
Garbage collect long time obsoleted (or never used) stuff from routing API

Only attempt to define behavior for these cases if they are defined.

ticket: 7955 (new)
tags: pullup
target_version: 1.12.2