diff options
| author | Daniel Mack <daniel@zonque.org> | 2015-07-10 20:44:46 -0400 |
|---|---|---|
| committer | Daniel Mack <daniel@zonque.org> | 2015-12-08 16:41:45 +0100 |
| commit | 4e5bf5e15899de3f9d11c2ddfe9721d9f8b07a37 (patch) | |
| tree | 910ca3de1b0d59411ce0e5bdbce665dbff6a6510 /src | |
| parent | bc7702b098b63031767174206f5df14a8ccb45cf (diff) | |
resolved: add packet header details for mDNS
Validate mDNS queries and responses by looking at some header fields,
add mDNS flags.
Diffstat (limited to 'src')
| -rw-r--r-- | src/resolve/resolved-def.h | 6 | ||||
| -rw-r--r-- | src/resolve/resolved-dns-packet.c | 29 | ||||
| -rw-r--r-- | src/resolve/resolved-dns-packet.h | 3 | ||||
| -rw-r--r-- | src/resolve/resolved-dns-transaction.c | 12 |
4 files changed, 49 insertions, 1 deletions
diff --git a/src/resolve/resolved-def.h b/src/resolve/resolved-def.h index db5ee57b51..6014d345f3 100644 --- a/src/resolve/resolved-def.h +++ b/src/resolve/resolved-def.h @@ -24,6 +24,8 @@ #define SD_RESOLVED_DNS (UINT64_C(1) << 0) #define SD_RESOLVED_LLMNR_IPV4 (UINT64_C(1) << 1) #define SD_RESOLVED_LLMNR_IPV6 (UINT64_C(1) << 2) +#define SD_RESOLVED_MDNS_IPV4 (UINT64_C(1) << 3) +#define SD_RESOLVED_MDNS_IPV6 (UINT64_C(1) << 4) #define SD_RESOLVED_NO_CNAME (UINT64_C(1) << 5) #define SD_RESOLVED_NO_TXT (UINT64_C(1) << 6) #define SD_RESOLVED_NO_ADDRESS (UINT64_C(1) << 7) @@ -31,4 +33,6 @@ #define SD_RESOLVED_AUTHENTICATED (UINT64_C(1) << 9) #define SD_RESOLVED_LLMNR (SD_RESOLVED_LLMNR_IPV4|SD_RESOLVED_LLMNR_IPV6) -#define SD_RESOLVED_PROTOCOLS_ALL (SD_RESOLVED_LLMNR|SD_RESOLVED_DNS) +#define SD_RESOLVED_MDNS (SD_RESOLVED_MDNS_IPV4|SD_RESOLVED_MDNS_IPV6) + +#define SD_RESOLVED_PROTOCOLS_ALL (SD_RESOLVED_MDNS|SD_RESOLVED_LLMNR|SD_RESOLVED_DNS) diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c index ea776f7916..3a4482a1b7 100644 --- a/src/resolve/resolved-dns-packet.c +++ b/src/resolve/resolved-dns-packet.c @@ -88,6 +88,16 @@ int dns_packet_new_query(DnsPacket **ret, DnsProtocol protocol, size_t mtu, bool 0 /* ad */, 0 /* cd */, 0 /* rcode */)); + else if (protocol == DNS_PROTOCOL_MDNS) + h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0 /* qr */, + 0 /* opcode */, + 0 /* aa */, + 0 /* tc */, + 0 /* rd (ask for recursion) */, + 0 /* ra */, + 0 /* ad */, + 0 /* cd */, + 0 /* rcode */)); else h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0 /* qr */, 0 /* opcode */, @@ -182,6 +192,13 @@ int dns_packet_validate_reply(DnsPacket *p) { break; + case DNS_PROTOCOL_MDNS: + /* RFC 6762, Section 18 */ + if (DNS_PACKET_RCODE(p) != 0) + return -EBADMSG; + + break; + default: break; } @@ -223,6 +240,18 @@ int dns_packet_validate_query(DnsPacket *p) { break; + case DNS_PROTOCOL_MDNS: + /* RFC 6762, Section 18 */ + if (DNS_PACKET_AA(p) != 0 || + DNS_PACKET_RD(p) != 0 || + DNS_PACKET_RA(p) != 0 || + DNS_PACKET_AD(p) != 0 || + DNS_PACKET_CD(p) != 0 || + DNS_PACKET_RCODE(p) != 0) + return -EBADMSG; + + break; + default: break; } diff --git a/src/resolve/resolved-dns-packet.h b/src/resolve/resolved-dns-packet.h index aa2823cfb9..1d275f8110 100644 --- a/src/resolve/resolved-dns-packet.h +++ b/src/resolve/resolved-dns-packet.h @@ -239,6 +239,9 @@ static inline uint64_t SD_RESOLVED_FLAGS_MAKE(DnsProtocol protocol, int family, case DNS_PROTOCOL_LLMNR: return f|(family == AF_INET6 ? SD_RESOLVED_LLMNR_IPV6 : SD_RESOLVED_LLMNR_IPV4); + case DNS_PROTOCOL_MDNS: + return family == AF_INET6 ? SD_RESOLVED_MDNS_IPV6 : SD_RESOLVED_MDNS_IPV4; + default: break; } diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c index 1103a34c6f..f77931ed53 100644 --- a/src/resolve/resolved-dns-transaction.c +++ b/src/resolve/resolved-dns-transaction.c @@ -384,6 +384,18 @@ void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p) { break; + case DNS_PROTOCOL_MDNS: + assert(t->scope->link); + + /* For mDNS we will not accept any packets from other interfaces */ + if (p->ifindex != t->scope->link->ifindex) + return; + + if (p->family != t->scope->family) + return; + + break; + case DNS_PROTOCOL_DNS: break; |