};
#define DNS_PACKET_HEADER_SIZE sizeof(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 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;
size_t size, allocated, rindex;
Hashmap *names; /* For name compression */
void *data;
- int ifindex;
};
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)
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);
enum {