From 8b4198373b976035e0dfc347f50b61eab40c8e00 Mon Sep 17 00:00:00 2001 From: Dmitry Rozhkov Date: Fri, 2 Dec 2016 13:54:02 +0200 Subject: [PATCH] resolved: install answers to mDNS transactions too Currently resolving mDNS requests doesn't work because in dns_transaction_process_reply() no answer gets installed into mDNS transactions. When receiving a mDNS reply we should not check for query section equivalence of the request and its corresponsing response. But still we need to install answers to mDNS transactions to make it possible to actually resolve mDNS requests. Signed-off-by: Dmitry Rozhkov --- src/resolve/resolved-dns-transaction.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c index 2fce44ec8b..ba38e0af78 100644 --- a/src/resolve/resolved-dns-transaction.c +++ b/src/resolve/resolved-dns-transaction.c @@ -1003,15 +1003,20 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { if (r > 0) /* Transaction got restarted... */ return; - if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR)) { + if (IN_SET(t->scope->protocol, DNS_PROTOCOL_DNS, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) { - /* Only consider responses with equivalent query section to the request */ - r = dns_packet_is_reply_for(p, t->key); - if (r < 0) - goto fail; - if (r == 0) { - dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); - return; + /* When dealing with protocols other than mDNS only consider responses with + * equivalent query section to the request. For mDNS this check doesn't make + * sense, because the section 6 of RFC6762 states that "Multicast DNS responses MUST NOT + * contain any questions in the Question Section". */ + if (t->scope->protocol != DNS_PROTOCOL_MDNS) { + r = dns_packet_is_reply_for(p, t->key); + if (r < 0) + goto fail; + if (r == 0) { + dns_transaction_complete(t, DNS_TRANSACTION_INVALID_REPLY); + return; + } } /* Install the answer as answer to the transaction */