diff options
Diffstat (limited to 'lib/dns/resolver.c')
| -rw-r--r-- | lib/dns/resolver.c | 50 |
1 files changed, 38 insertions, 12 deletions
diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c index 4c8b144486be..503f1d23b92f 100644 --- a/lib/dns/resolver.c +++ b/lib/dns/resolver.c @@ -105,8 +105,21 @@ #define QTRACE(m) #endif +#define US_PER_SEC 1000000U +/* + * The maximum time we will wait for a single query. + */ +#define MAX_SINGLE_QUERY_TIMEOUT 9U +#define MAX_SINGLE_QUERY_TIMEOUT_US (MAX_SINGLE_QUERY_TIMEOUT*US_PER_SEC) + +/* + * We need to allow a individual query time to complete / timeout. + */ +#define MINIMUM_QUERY_TIMEOUT (MAX_SINGLE_QUERY_TIMEOUT + 1U) + +/* The default time in seconds for the whole query to live. */ #ifndef DEFAULT_QUERY_TIMEOUT -#define DEFAULT_QUERY_TIMEOUT 30 /* The default time in seconds for the whole query to live. */ +#define DEFAULT_QUERY_TIMEOUT MINIMUM_QUERY_TIMEOUT #endif #ifndef MAXIMUM_QUERY_TIMEOUT @@ -821,8 +834,8 @@ fctx_cancelquery(resquery_t **queryp, dns_dispatchevent_t **deventp, */ INSIST(no_response); rtt = query->addrinfo->srtt + 200000; - if (rtt > 10000000) - rtt = 10000000; + if (rtt > MAX_SINGLE_QUERY_TIMEOUT_US) + rtt = MAX_SINGLE_QUERY_TIMEOUT_US; /* * Replace the current RTT with our value. */ @@ -1336,12 +1349,18 @@ fctx_setretryinterval(fetchctx_t *fctx, unsigned int rtt) { us = (800000 << (fctx->restarts - 2)); /* - * Double the round-trip time. + * Add a fudge factor to the expected rtt based on the current + * estimate. */ - rtt *= 2; + if (rtt < 50000) + rtt += 50000; + else if (rtt < 100000) + rtt += 100000; + else + rtt += 200000; /* - * Always wait for at least the doubled round-trip time. + * Always wait for at least the expected rtt. */ if (us < rtt) us = rtt; @@ -1349,11 +1368,11 @@ fctx_setretryinterval(fetchctx_t *fctx, unsigned int rtt) { /* * But don't ever wait for more than 10 seconds. */ - if (us > 10000000) - us = 10000000; + if (us > MAX_SINGLE_QUERY_TIMEOUT_US) + us = MAX_SINGLE_QUERY_TIMEOUT_US; - seconds = us / 1000000; - us -= seconds * 1000000; + seconds = us / US_PER_SEC; + us -= seconds * US_PER_SEC; isc_interval_set(&fctx->interval, seconds, us * 1000); } @@ -1375,6 +1394,11 @@ fctx_query(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, task = res->buckets[fctx->bucketnum].task; srtt = addrinfo->srtt; + + /* + * A forwarder needs to make multiple queries. Give it at least + * a second to do these in. + */ if (ISFORWARDER(addrinfo) && srtt < 1000000) srtt = 1000000; @@ -8211,8 +8235,8 @@ dns_resolver_logfetch(dns_fetch_t *fetch, isc_log_t *lctx, "timeout:%u,lame:%u,neterr:%u,badresp:%u," "adberr:%u,findfail:%u,valfail:%u]", __FILE__, fctx->exitline, fctx->info, - fctx->duration / 1000000, - fctx->duration % 1000000, + fctx->duration / US_PER_SEC, + fctx->duration % US_PER_SEC, isc_result_totext(fctx->result), isc_result_totext(fctx->vresult), domainbuf, fctx->referrals, fctx->restarts, @@ -8818,6 +8842,8 @@ dns_resolver_settimeout(dns_resolver_t *resolver, unsigned int seconds) { seconds = DEFAULT_QUERY_TIMEOUT; if (seconds > MAXIMUM_QUERY_TIMEOUT) seconds = MAXIMUM_QUERY_TIMEOUT; + if (seconds < MINIMUM_QUERY_TIMEOUT) + seconds = MINIMUM_QUERY_TIMEOUT; resolver->query_timeout = seconds; } |