]> git.ipfire.org Git - thirdparty/systemd.git/blobdiff - src/resolve/resolved-dns-packet.h
resolved: cache stringified transaction key once per transaction
[thirdparty/systemd.git] / src / resolve / resolved-dns-packet.h
index fbbabaf232d7d47e767866bbf9b35317c8c8ebaf..082e92833c3065821319dd6ad9dc9d1cb46c139d 100644 (file)
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  ***/
 
-#include <netinet/udp.h>
 #include <netinet/ip.h>
+#include <netinet/udp.h>
 
-#include "macro.h"
-#include "sparse-endian.h"
 #include "hashmap.h"
 #include "in-addr-util.h"
+#include "macro.h"
+#include "sparse-endian.h"
 
 typedef struct DnsPacketHeader DnsPacketHeader;
 typedef struct DnsPacket DnsPacket;
 
-#include "resolved-dns-rr.h"
-#include "resolved-dns-question.h"
-#include "resolved-dns-answer.h"
 #include "resolved-def.h"
+#include "resolved-dns-answer.h"
+#include "resolved-dns-question.h"
+#include "resolved-dns-rr.h"
 
 typedef enum DnsProtocol {
         DNS_PROTOCOL_DNS,
@@ -65,6 +65,9 @@ struct DnsPacketHeader {
 /* RFC 1035 say 512 is the maximum, for classic unicast DNS */
 #define DNS_PACKET_UNICAST_SIZE_MAX 512
 
+/* With EDNS0 we can use larger packets, default to 4096, which is what is commonly used */
+#define DNS_PACKET_UNICAST_SIZE_LARGE_MAX 4096
+
 #define DNS_PACKET_SIZE_START 512
 
 struct DnsPacket {
@@ -77,6 +80,7 @@ struct DnsPacket {
         /* Parsed data */
         DnsQuestion *question;
         DnsAnswer *answer;
+        DnsResourceRecord *opt;
 
         /* Packet reception metadata */
         int ifindex;
@@ -85,8 +89,13 @@ struct DnsPacket {
         uint16_t sender_port, destination_port;
         uint32_t ttl;
 
-        bool extracted;
-        bool refuse_compression;
+        /* For support of truncated packets */
+        DnsPacket *more;
+
+        bool on_stack:1;
+        bool extracted:1;
+        bool refuse_compression:1;
+        bool canonical_form:1;
 };
 
 static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) {
@@ -139,7 +148,9 @@ static inline unsigned DNS_PACKET_RRCOUNT(DnsPacket *p) {
 }
 
 int dns_packet_new(DnsPacket **p, DnsProtocol protocol, size_t mtu);
-int dns_packet_new_query(DnsPacket **p, DnsProtocol protocol, size_t mtu);
+int dns_packet_new_query(DnsPacket **p, DnsProtocol protocol, size_t mtu, bool dnssec_checking_disabled);
+
+void dns_packet_set_flags(DnsPacket *p, bool dnssec_checking_disabled, bool truncated);
 
 DnsPacket *dns_packet_ref(DnsPacket *p);
 DnsPacket *dns_packet_unref(DnsPacket *p);
@@ -150,16 +161,21 @@ int dns_packet_validate(DnsPacket *p);
 int dns_packet_validate_reply(DnsPacket *p);
 int dns_packet_validate_query(DnsPacket *p);
 
+int dns_packet_is_reply_for(DnsPacket *p, const DnsResourceKey *key);
+
 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,
-                           bool allow_compression, size_t *start);
+int dns_packet_append_raw_string(DnsPacket *p, const void *s, size_t size, size_t *start);
+int dns_packet_append_label(DnsPacket *p, const char *s, size_t l, bool canonical_candidate, size_t *start);
+int dns_packet_append_name(DnsPacket *p, const char *name, bool allow_compression, bool canonical_candidate, 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_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start, size_t *rdata_start);
+int dns_packet_append_opt_rr(DnsPacket *p, uint16_t max_udp_size, bool edns0_do, size_t *start);
+
+void dns_packet_truncate(DnsPacket *p, size_t sz);
 
 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);
@@ -167,8 +183,8 @@ 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,
-                         bool allow_compression, size_t *start);
+int dns_packet_read_raw_string(DnsPacket *p, const void **ret, size_t *size, size_t *start);
+int dns_packet_read_name(DnsPacket *p, char **ret, bool allow_compression, 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);
 
@@ -177,6 +193,14 @@ void dns_packet_rewind(DnsPacket *p, size_t idx);
 int dns_packet_skip_question(DnsPacket *p);
 int dns_packet_extract(DnsPacket *p);
 
+static inline bool DNS_PACKET_SHALL_CACHE(DnsPacket *p) {
+        /* Never cache data originating from localhost, under the
+         * assumption, that it's coming from a locally DNS forwarder
+         * or server, that is caching on its own. */
+
+        return in_addr_is_localhost(p->family, &p->sender) == 0;
+}
+
 enum {
         DNS_RCODE_SUCCESS = 0,
         DNS_RCODE_FORMERR = 1,
@@ -209,42 +233,25 @@ 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 } })
 
-#define DNSKEY_FLAG_ZONE_KEY (1u << 8)
-#define DNSKEY_FLAG_SEP      (1u << 0)
+#define MDNS_MULTICAST_IPV4_ADDRESS  ((struct in_addr) { .s_addr = htobe32(224U << 24 | 251U) })
+#define MDNS_MULTICAST_IPV6_ADDRESS  ((struct in6_addr) { .s6_addr = { 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0xfb } })
 
-static inline uint16_t dnskey_to_flags(const DnsResourceRecord *rr) {
-        return (rr->dnskey.zone_key_flag * DNSKEY_FLAG_ZONE_KEY |
-                rr->dnskey.sep_flag * DNSKEY_FLAG_SEP);
-}
-
-/* http://tools.ietf.org/html/rfc4034#appendix-A.1 */
-enum {
-        DNSSEC_ALGORITHM_RSAMD5 = 1,
-        DNSSEC_ALGORITHM_DH,
-        DNSSEC_ALGORITHM_DSA,
-        DNSSEC_ALGORITHM_ECC,
-        DNSSEC_ALGORITHM_RSASHA1,
-        DNSSEC_ALGORITHM_DSA_NSEC3_SHA1,
-        DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1,
-        DNSSEC_ALGORITHM_INDIRECT = 252,
-        DNSSEC_ALGORITHM_PRIVATEDNS,
-        DNSSEC_ALGORITHM_PRIVATEOID,
-        _DNSSEC_ALGORITHM_MAX_DEFINED
-};
-
-const char* dnssec_algorithm_to_string(int i) _const_;
-int dnssec_algorithm_from_string(const char *s) _pure_;
+static inline uint64_t SD_RESOLVED_FLAGS_MAKE(DnsProtocol protocol, int family, bool authenticated) {
+        uint64_t f;
 
-static inline uint64_t SD_RESOLVED_FLAGS_MAKE(DnsProtocol protocol, int family) {
+        /* Converts a protocol + family into a flags field as used in queries and responses */
 
-        /* Converts a protocol + family into a flags field as used in queries */
+        f = authenticated ? SD_RESOLVED_AUTHENTICATED : 0;
 
         switch (protocol) {
         case DNS_PROTOCOL_DNS:
-                return SD_RESOLVED_DNS;
+                return f|SD_RESOLVED_DNS;
 
         case DNS_PROTOCOL_LLMNR:
-                return family == AF_INET6 ? SD_RESOLVED_LLMNR_IPV6 : SD_RESOLVED_LLMNR_IPV4;
+                return f|(family == AF_INET6 ? SD_RESOLVED_LLMNR_IPV6 : SD_RESOLVED_LLMNR_IPV4);
+
+        case DNS_PROTOCOL_MDNS:
+                return family == AF_INET6 ? SD_RESOLVED_MDNS_IPV6 : SD_RESOLVED_MDNS_IPV4;
 
         default:
                 break;