Honor the TTL value of SRV record lookups

Add new resolv_hostent data structure and utility functions

Resolve hosts by name from files into resolv_hostent

Resolve hosts by name from DNS into resolv_hostent

Switch resolver to using resolv_hostent and honor TTL

Conflicts:

	src/providers/fail_over.c

Provide TTL structure names for c-ares < 1.7

https://fedorahosted.org/sssd/ticket/898

In c-ares 1.7, the upstream renamed the addrttl/addr6ttl structures to
ares_addrttl/ares_addr6ttl so they are in the ares_ namespace.

Because they are committed to stable ABI, the contents are the same, just
the name changed -- so it is safe to just #define the new name for older
c-ares version in case the new one is not detected in configure time.

1 files changed, 5 insertions, 4 deletions

diff --git a/src/providers/data_provider_fo.c b/src/providers/data_provider_fo.c
index f1e1e137c..58468c820 100644
--- a/src/providers/data_provider_fo.c
+++ b/src/providers/data_provider_fo.c
@@ -453,14 +453,15 @@ static void be_resolve_server_done(struct tevent_req *subreq)
     /* all fine we got the server */
 
     if (debug_level >= 4) {
-        struct hostent *srvaddr;
+        struct resolv_hostent *srvaddr;
         char ipaddr[128];
         srvaddr = fo_get_server_hostent(state->srv);
-        inet_ntop(srvaddr->h_addrtype, srvaddr->h_addr_list[0],
+        inet_ntop(srvaddr->family, srvaddr->addr_list[0]->ipaddr,
                   ipaddr, 128);
 
-        DEBUG(4, ("Found address for server %s: [%s]\n",
-                  fo_get_server_name(state->srv), ipaddr));
+        DEBUG(4, ("Found address for server %s: [%s] TTL %d\n",
+                  fo_get_server_name(state->srv), ipaddr,
+                  srvaddr->addr_list[0]->ttl));
     }
 
     srv_status_change = fo_get_server_hostname_last_change(state->srv);