resolved: add DNS cache

[elogind.git] / src / resolve / resolved-dns-packet.h

diff --git a/src/resolve/resolved-dns-packet.h b/src/resolve/resolved-dns-packet.h
index 10f8f96915c19275030264c4b55af0bd3424bda2..67c7bc3dfc62efc99d6510217150d69e28f941d7 100644 (file)
--- a/src/resolve/resolved-dns-packet.h
+++ b/src/resolve/resolved-dns-packet.h
@@ -44,8 +44,12 @@ 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 {
@@ -53,6 +57,7 @@ struct DnsPacket {
         int ifindex;
         size_t size, allocated, rindex;
         Hashmap *names; /* For name compression */
+        DnsResourceRecord **rrs;
         void *data;
 };
 
@@ -71,6 +76,7 @@ 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)
@@ -87,6 +93,12 @@ 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);
@@ -115,7 +127,10 @@ 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,