diff options
Diffstat (limited to 'src/resolve/resolved-dns-server.c')
| -rw-r--r-- | src/resolve/resolved-dns-server.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/src/resolve/resolved-dns-server.c b/src/resolve/resolved-dns-server.c index 916f5dadb8..d565f99c09 100644 --- a/src/resolve/resolved-dns-server.c +++ b/src/resolve/resolved-dns-server.c @@ -71,6 +71,7 @@ int dns_server_new( s->verified_features = _DNS_SERVER_FEATURE_LEVEL_INVALID; s->possible_features = DNS_SERVER_FEATURE_LEVEL_BEST; s->features_grace_period_usec = DNS_SERVER_FEATURE_GRACE_PERIOD_MIN_USEC; + s->received_udp_packet_max = DNS_PACKET_UNICAST_SIZE_MAX; s->type = type; s->family = family; s->address = *in_addr; @@ -223,10 +224,18 @@ void dns_server_move_back_and_unmark(DnsServer *s) { } } -void dns_server_packet_received(DnsServer *s, DnsServerFeatureLevel features, usec_t rtt) { +void dns_server_packet_received(DnsServer *s, DnsServerFeatureLevel features, usec_t rtt, size_t size) { assert(s); - if (s->verified_features < features) { + if (features == DNS_SERVER_FEATURE_LEVEL_LARGE) { + /* even if we successfully receive a reply to a request announcing + support for large packets, that does not mean we can necessarily + receive large packets. */ + if (s->verified_features < DNS_SERVER_FEATURE_LEVEL_LARGE - 1) { + s->verified_features = DNS_SERVER_FEATURE_LEVEL_LARGE - 1; + assert_se(sd_event_now(s->manager->event, clock_boottime_or_monotonic(), &s->verified_usec) >= 0); + } + } else if (s->verified_features < features) { s->verified_features = features; assert_se(sd_event_now(s->manager->event, clock_boottime_or_monotonic(), &s->verified_usec) >= 0); } @@ -234,6 +243,12 @@ void dns_server_packet_received(DnsServer *s, DnsServerFeatureLevel features, us if (s->possible_features == features) s->n_failed_attempts = 0; + /* Remember the size of the largest UDP packet we received from a server, + we know that we can always announce support for packets with at least + this size. */ + if (s->received_udp_packet_max < size) + s->received_udp_packet_max = size; + if (s->max_rtt < rtt) { s->max_rtt = rtt; s->resend_timeout = MIN(MAX(DNS_TIMEOUT_MIN_USEC, s->max_rtt * 2), DNS_TIMEOUT_MAX_USEC); @@ -480,5 +495,6 @@ static const char* const dns_server_feature_level_table[_DNS_SERVER_FEATURE_LEVE [DNS_SERVER_FEATURE_LEVEL_UDP] = "UDP", [DNS_SERVER_FEATURE_LEVEL_EDNS0] = "UDP+EDNS0", [DNS_SERVER_FEATURE_LEVEL_DO] = "UDP+EDNS0+DO", + [DNS_SERVER_FEATURE_LEVEL_LARGE] = "UDP+EDNS0+DO+LARGE", }; DEFINE_STRING_TABLE_LOOKUP(dns_server_feature_level, DnsServerFeatureLevel); |