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=4e3001911e7c74a64e27ff9c4946c699b286a5fc;hp=77edc05a1910956f93b29f1f92812dd4107db1fe;hb=8db0d2f5c37e7e8f5bfce016cfdad7947a3ea939;hpb=3cb10d3a0b1b6a7c44f307f2abb5215104e16941
diff --git a/src/resolve/resolved-dns-packet.h b/src/resolve/resolved-dns-packet.h
index 77edc05a1..4e3001911 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;
@@ -41,22 +53,42 @@ 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 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;
+ 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));
}
@@ -66,6 +98,9 @@ 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_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)
@@ -82,9 +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);
@@ -93,24 +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,
@@ -137,3 +186,17 @@ 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 } })
+
+#define DNSKEY_FLAG_ZONE_KEY (1u << 8)
+#define DNSKEY_FLAG_SEP (1u << 0)
+
+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);
+}