dns-domain: enforce maximum DNS domain name length

[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 18ed4ba0d788fc6ddeace6cbed03b21d181d956f..99f60a15569526c2c9024279170c2e516e2b1647 100644 (file)
--- a/src/resolve/resolved-dns-packet.h
+++ b/src/resolve/resolved-dns-packet.h
@@ -41,14 +41,19 @@ struct DnsPacketHeader {
 };
 
 #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 maximum. */
+#define DNS_PACKET_SIZE_MAX 0xFFFF
 #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) {
@@ -62,6 +67,27 @@ static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) {
 }
 
 #define DNS_PACKET_HEADER(p) ((DnsPacketHeader*) DNS_PACKET_DATA(p))
+#define DNS_PACKET_ID(p) DNS_PACKET_HEADER(p)->id
+#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)
+#define DNS_PACKET_ARCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->arcount)
+
+#define DNS_PACKET_MAKE_FLAGS(qr, opcode, aa, tc, rd, ra, ad, cd, rcode) \
+        (((uint16_t) !!qr << 15) |  \
+         ((uint16_t) (opcode & 15) << 11) | \
+         ((uint16_t) !!aa << 10) | \
+         ((uint16_t) !!tc << 9) | \
+         ((uint16_t) !!rd << 8) | \
+         ((uint16_t) !!ra << 7) | \
+         ((uint16_t) !!ad << 5) | \
+         ((uint16_t) !!cd << 4) | \
+         ((uint16_t) (rcode & 15)))
+
 
 int dns_packet_new(DnsPacket **p, size_t mtu);
 int dns_packet_new_query(DnsPacket **p, size_t mtu);
@@ -90,20 +116,9 @@ 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);
 
-int dns_packet_skip_question(DnsPacket *p);
+void dns_packet_rewind(DnsPacket *p, size_t idx);
 
-#define DNS_PACKET_MAKE_FLAGS(qr, opcode, aa, tc, rd, ra, ad, cd, rcode) \
-        (((uint16_t) !!qr << 15) |  \
-         ((uint16_t) (opcode & 15) << 11) | \
-         ((uint16_t) !!aa << 10) | \
-         ((uint16_t) !!tc << 9) | \
-         ((uint16_t) !!rd << 8) | \
-         ((uint16_t) !!ra << 7) | \
-         ((uint16_t) !!ad << 5) | \
-         ((uint16_t) !!cd << 4) | \
-         ((uint16_t) (rcode & 15)))
-
-#define DNS_PACKET_RCODE(p) (be16toh(DNS_PACKET_HEADER(p)->flags) & 15)
+int dns_packet_skip_question(DnsPacket *p);
 
 enum {
         DNS_RCODE_SUCCESS = 0,