From 818ef443f0281acd952878cdb01cbdaa42195912 Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Sat, 11 Jul 2015 12:37:17 -0400 Subject: resolved: make LLMNR checks conditional Make all LLMNR related packet inspections conditional to p->protocol. Use switch-case statements while at it, which will make future additions more readable. --- src/resolve/resolved-dns-packet.c | 42 ++++++++++++++++++++++++++------------- 1 file changed, 28 insertions(+), 14 deletions(-) (limited to 'src/resolve/resolved-dns-packet.c') diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c index 47cc9751ed..fa0516f8a0 100644 --- a/src/resolve/resolved-dns-packet.c +++ b/src/resolve/resolved-dns-packet.c @@ -166,10 +166,17 @@ int dns_packet_validate_reply(DnsPacket *p) { if (DNS_PACKET_OPCODE(p) != 0) return -EBADMSG; - /* RFC 4795, Section 2.1.1. says to discard all replies with QDCOUNT != 1 */ - if (p->protocol == DNS_PROTOCOL_LLMNR && - DNS_PACKET_QDCOUNT(p) != 1) - return -EBADMSG; + switch (p->protocol) { + case DNS_PROTOCOL_LLMNR: + /* RFC 4795, Section 2.1.1. says to discard all replies with QDCOUNT != 1 */ + if (DNS_PACKET_QDCOUNT(p) != 1) + return -EBADMSG; + + break; + + default: + break; + } return 1; } @@ -192,18 +199,25 @@ int dns_packet_validate_query(DnsPacket *p) { if (DNS_PACKET_TC(p)) return -EBADMSG; - /* RFC 4795, Section 2.1.1. says to discard all queries with QDCOUNT != 1 */ - if (p->protocol == DNS_PROTOCOL_LLMNR && - DNS_PACKET_QDCOUNT(p) != 1) - return -EBADMSG; + switch (p->protocol) { + case DNS_PROTOCOL_LLMNR: + /* RFC 4795, Section 2.1.1. says to discard all queries with QDCOUNT != 1 */ + if (DNS_PACKET_QDCOUNT(p) != 1) + return -EBADMSG; - /* RFC 4795, Section 2.1.1. says to discard all queries with ANCOUNT != 0 */ - if (DNS_PACKET_ANCOUNT(p) > 0) - return -EBADMSG; + /* RFC 4795, Section 2.1.1. says to discard all queries with ANCOUNT != 0 */ + if (DNS_PACKET_ANCOUNT(p) > 0) + return -EBADMSG; - /* RFC 4795, Section 2.1.1. says to discard all queries with NSCOUNT != 0 */ - if (DNS_PACKET_NSCOUNT(p) > 0) - return -EBADMSG; + /* RFC 4795, Section 2.1.1. says to discard all queries with NSCOUNT != 0 */ + if (DNS_PACKET_NSCOUNT(p) > 0) + return -EBADMSG; + + break; + + default: + break; + } return 1; } -- cgit v1.2.3-54-g00ecf