X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fresolve%2Fresolved-dns-packet.h;h=af51f16c3c8dac822933260b3f2371bd49db2462;hp=d4c9c475f5b1559a2ec45c7425bb5e7fde192ae6;hb=2d4c5cbc0ed3ccb09dc086a040088b454c22c644;hpb=ad867662936a4c7ab2c7116d804c272338801231 diff --git a/src/resolve/resolved-dns-packet.h b/src/resolve/resolved-dns-packet.h index d4c9c475f..af51f16c3 100644 --- a/src/resolve/resolved-dns-packet.h +++ b/src/resolve/resolved-dns-packet.h @@ -21,15 +21,27 @@ along with systemd; If not, see . ***/ -typedef struct DnsPacketHeader DnsPacketHeader; -typedef struct DnsPacket DnsPacket; - #include #include "macro.h" #include "sparse-endian.h" #include "hashmap.h" +#include "in-addr-util.h" + +typedef struct DnsPacketHeader DnsPacketHeader; +typedef struct DnsPacket DnsPacket; + #include "resolved-dns-rr.h" +#include "resolved-dns-question.h" +#include "resolved-dns-answer.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; @@ -44,24 +56,39 @@ 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; + void *_data; /* don't access directly, use DNS_PACKET_DATA()! */ Hashmap *names; /* For name compression */ - void *data; + + /* Parsed data */ + DnsQuestion *question; + DnsAnswer *answer; + + /* Packet reception meta data */ + int ifindex; + int family, ipproto; + union in_addr_union sender, destination; + uint16_t sender_port, destination_port; + uint32_t ttl; }; static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) { if (_unlikely_(!p)) return NULL; - if (p->data) - return p->data; + if (p->_data) + return p->_data; return ((uint8_t*) p) + ALIGN(sizeof(DnsPacket)); } @@ -72,6 +99,8 @@ static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) { #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_C(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 10) & 1) +#define DNS_PACKET_T(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 8) & 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) @@ -88,9 +117,15 @@ 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); @@ -99,24 +134,32 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(DnsPacket*, dns_packet_unref); int dns_packet_validate(DnsPacket *p); int dns_packet_validate_reply(DnsPacket *p); +int dns_packet_validate_query(DnsPacket *p); +int dns_packet_append_blob(DnsPacket *p, const void *d, size_t sz, size_t *start); int dns_packet_append_uint8(DnsPacket *p, uint8_t v, size_t *start); int dns_packet_append_uint16(DnsPacket *p, uint16_t v, size_t *start); +int dns_packet_append_uint32(DnsPacket *p, uint32_t v, size_t *start); int dns_packet_append_string(DnsPacket *p, const char *s, size_t *start); int dns_packet_append_label(DnsPacket *p, const char *s, size_t l, size_t *start); int dns_packet_append_name(DnsPacket *p, const char *name, size_t *start); -int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *k, size_t *start); +int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *key, size_t *start); +int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start); int dns_packet_read(DnsPacket *p, size_t sz, const void **ret, size_t *start); +int dns_packet_read_blob(DnsPacket *p, void *d, size_t sz, size_t *start); int dns_packet_read_uint8(DnsPacket *p, uint8_t *ret, size_t *start); int dns_packet_read_uint16(DnsPacket *p, uint16_t *ret, size_t *start); int dns_packet_read_uint32(DnsPacket *p, uint32_t *ret, size_t *start); int dns_packet_read_string(DnsPacket *p, char **ret, size_t *start); 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_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(DnsPacket *p); enum { DNS_RCODE_SUCCESS = 0, @@ -143,3 +186,9 @@ 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 } })