X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fresolve%2Fresolved-dns-packet.h;h=4fd2d408ce84c41e968866e12273906675262140;hb=cbd4560ea2c9f0ae77df1fc64685ff4e559810b6;hp=10f8f96915c19275030264c4b55af0bd3424bda2;hpb=c73ce96b569e2f10dff64b7dc0bd271972674c2a;p=elogind.git diff --git a/src/resolve/resolved-dns-packet.h b/src/resolve/resolved-dns-packet.h index 10f8f9691..4fd2d408c 100644 --- a/src/resolve/resolved-dns-packet.h +++ b/src/resolve/resolved-dns-packet.h @@ -31,6 +31,14 @@ typedef struct DnsPacket DnsPacket; #include "hashmap.h" #include "resolved-dns-rr.h" +typedef enum DnsProtocol { + DNS_PROTOCOL_DNS, + DNS_PROTOCOL_MDNS, + DNS_PROTOCOL_LLMNR, + _DNS_PROTOCOL_MAX, + _DNS_PROTOCOL_INVALID = -1 +} DnsProtocol; + struct DnsPacketHeader { uint16_t id; be16_t flags; @@ -44,16 +52,27 @@ struct DnsPacketHeader { /* The various DNS protocols deviate in how large a packet can grow, but the TCP transport has a 16bit size field, hence that appears to - be the maximum. */ + be the absolute maximum. */ #define DNS_PACKET_SIZE_MAX 0xFFFF + +/* RFC 1035 say 512 is the maximum, for classic unicast DNS */ +#define DNS_PACKET_UNICAST_SIZE_MAX 512 + #define DNS_PACKET_SIZE_START 512 struct DnsPacket { int n_ref; - int ifindex; + DnsProtocol protocol; size_t size, allocated, rindex; - Hashmap *names; /* For name compression */ void *data; + Hashmap *names; /* For name compression */ + DnsResourceRecord **rrs; + + /* Packet reception meta data */ + int ifindex; + int family; + union in_addr_union sender, destination; + uint32_t ttl; }; static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) { @@ -71,6 +90,7 @@ static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) { #define DNS_PACKET_QR(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 15) & 1) #define DNS_PACKET_OPCODE(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 11) & 15) #define DNS_PACKET_RCODE(p) (be16toh(DNS_PACKET_HEADER(p)->flags) & 15) +#define DNS_PACKET_TC(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 9) & 1) #define DNS_PACKET_QDCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->qdcount) #define DNS_PACKET_ANCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->ancount) #define DNS_PACKET_NSCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->nscount) @@ -87,9 +107,15 @@ static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) { ((uint16_t) !!cd << 4) | \ ((uint16_t) (rcode & 15))) +static inline unsigned DNS_PACKET_RRCOUNT(DnsPacket *p) { + return + (unsigned) DNS_PACKET_ANCOUNT(p) + + (unsigned) DNS_PACKET_NSCOUNT(p) + + (unsigned) DNS_PACKET_ARCOUNT(p); +} -int dns_packet_new(DnsPacket **p, size_t mtu); -int dns_packet_new_query(DnsPacket **p, size_t mtu); +int dns_packet_new(DnsPacket **p, DnsProtocol protocol, size_t mtu); +int dns_packet_new_query(DnsPacket **p, DnsProtocol protocol, size_t mtu); DnsPacket *dns_packet_ref(DnsPacket *p); DnsPacket *dns_packet_unref(DnsPacket *p); @@ -115,7 +141,10 @@ int dns_packet_read_name(DnsPacket *p, char **ret, size_t *start); int dns_packet_read_key(DnsPacket *p, DnsResourceKey *ret, size_t *start); int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start); +void dns_packet_rewind(DnsPacket *p, size_t idx); + int dns_packet_skip_question(DnsPacket *p); +int dns_packet_extract_rrs(DnsPacket *p); enum { DNS_RCODE_SUCCESS = 0, @@ -142,3 +171,9 @@ enum { const char* dns_rcode_to_string(int i) _const_; int dns_rcode_from_string(const char *s) _pure_; + +const char* dns_protocol_to_string(DnsProtocol p) _const_; +DnsProtocol dns_protocol_from_string(const char *s) _pure_; + +#define LLMNR_MULTICAST_IPV4_ADDRESS ((struct in_addr) { .s_addr = htobe32(224U << 24 | 252U) }) +#define LLMNR_MULTICAST_IPV6_ADDRESS ((struct in6_addr) { .s6_addr = { 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x03 } })