Don't skip a server if it's the only one. (Bugfix from the Google tree.)

This commit is contained in:
Steinar H. Gunderson 2007-09-28 14:26:11 +00:00
parent 0819c3a8cf
commit 54ca7d8cb2
1 changed files with 23 additions and 5 deletions

View File

@ -65,6 +65,8 @@ static void process_timeouts(ares_channel channel, time_t now);
static void process_answer(ares_channel channel, unsigned char *abuf,
int alen, int whichserver, int tcp, time_t now);
static void handle_error(ares_channel channel, int whichserver, time_t now);
static void skip_server(ares_channel channel, struct query *query,
int whichserver);
static struct query *next_server(ares_channel channel, struct query *query, time_t now);
static int open_tcp_socket(ares_channel channel, struct server_state *server);
static int open_udp_socket(ares_channel channel, struct server_state *server);
@ -474,7 +476,7 @@ static void process_answer(ares_channel channel, unsigned char *abuf,
{
if (rcode == SERVFAIL || rcode == NOTIMP || rcode == REFUSED)
{
query->skip_server[whichserver] = 1;
skip_server(channel, query, whichserver);
if (query->server == whichserver)
next_server(channel, query, now);
return;
@ -506,12 +508,28 @@ static void handle_error(ares_channel channel, int whichserver, time_t now)
next = query->next;
if (query->server == whichserver)
{
query->skip_server[whichserver] = 1;
skip_server(channel, query, whichserver);
next = next_server(channel, query, now);
}
}
}
static void skip_server(ares_channel channel, struct query *query,
int whichserver) {
/* The given server gave us problems with this query, so if we have
* the luxury of using other servers, then let's skip the
* potentially broken server and just use the others. If we only
* have one server and we need to retry then we should just go ahead
* and re-use that server, since it's our only hope; perhaps we
* just got unlucky, and retrying will work (eg, the server timed
* out our TCP connection just as we were sending another request).
*/
if (channel->nservers > 1)
{
query->skip_server[whichserver] = 1;
}
}
static struct query *next_server(ares_channel channel, struct query *query, time_t now)
{
/* Advance to the next server or try. */
@ -553,7 +571,7 @@ void ares__send_query(ares_channel channel, struct query *query, time_t now)
{
if (open_tcp_socket(channel, server) == -1)
{
query->skip_server[query->server] = 1;
skip_server(channel, query, query->server);
next_server(channel, query, now);
return;
}
@ -583,7 +601,7 @@ void ares__send_query(ares_channel channel, struct query *query, time_t now)
{
if (open_udp_socket(channel, server) == -1)
{
query->skip_server[query->server] = 1;
skip_server(channel, query, query->server);
next_server(channel, query, now);
return;
}
@ -591,7 +609,7 @@ void ares__send_query(ares_channel channel, struct query *query, time_t now)
if (swrite(server->udp_socket, query->qbuf, query->qlen) == -1)
{
/* FIXME: Handle EAGAIN here since it likely can happen. */
query->skip_server[query->server] = 1;
skip_server(channel, query, query->server);
next_server(channel, query, now);
return;
}