libdns: Fix connect and try next nameserver when ECONNREFUSED.

* dirmngr/dns.c (dns_so_check): When EINVAL, release the association
by connect with AF_UNSPEC and try again.  Also try again for
ECONNREFUSED.
(dns_res_exec): Try next nameserver when ECONNREFUSED.

--

GnuPG-bug-id: T3374
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
This commit is contained in:
NIIBE Yutaka 2018-06-15 12:58:29 +09:00
parent 1c0b6681e4
commit bcdbf8b8eb
1 changed files with 23 additions and 2 deletions

View File

@ -7614,8 +7614,23 @@ retry:
so->state++; /* FALL THROUGH */
case DNS_SO_UDP_CONN:
udp_connect_retry:
error = dns_connect(so->udp, (struct sockaddr *)&so->remote, dns_sa_len(&so->remote));
dns_trace_sys_connect(so->trace, so->udp, SOCK_DGRAM, (struct sockaddr *)&so->remote, error);
/* Linux returns EINVAL when address was bound to
localhost and it's external IP address now. */
if (error == EINVAL) {
struct sockaddr unspec_addr;
memset (&unspec_addr, 0, sizeof unspec_addr);
unspec_addr.sa_family = AF_UNSPEC;
connect(so->udp, &unspec_addr, sizeof unspec_addr);
goto udp_connect_retry;
} else if (error == ECONNREFUSED)
/* Error for previous socket operation may
be reserverd asynchronously. */
goto udp_connect_retry;
if (error)
goto error;
@ -8824,7 +8839,10 @@ exec:
if (dns_so_elapsed(&R->so) >= dns_resconf_timeout(R->resconf))
dgoto(R->sp, DNS_R_FOREACH_A);
if ((error = dns_so_check(&R->so)))
error = dns_so_check(&R->so);
if (error == ECONNREFUSED)
dgoto(R->sp, DNS_R_FOREACH_A);
else if (error)
goto error;
if (!dns_p_setptr(&F->answer, dns_so_fetch(&R->so, &error)))
@ -8957,7 +8975,10 @@ exec:
if (dns_so_elapsed(&R->so) >= dns_resconf_timeout(R->resconf))
dgoto(R->sp, DNS_R_FOREACH_AAAA);
if ((error = dns_so_check(&R->so)))
error = dns_so_check(&R->so);
if (error == ECONNREFUSED)
dgoto(R->sp, DNS_R_FOREACH_AAAA);
else if (error)
goto error;
if (!dns_p_setptr(&F->answer, dns_so_fetch(&R->so, &error)))