We don't make use of this yet, but later work will.
}
/* Append the OPT pseudo-RR described in RFC6891 */
-int dns_packet_append_opt(DnsPacket *p, uint16_t max_udp_size, bool edns0_do, size_t *start) {
+int dns_packet_append_opt(DnsPacket *p, uint16_t max_udp_size, bool edns0_do, int rcode, size_t *start) {
size_t saved_size;
int r;
assert(p);
/* we must never advertise supported packet size smaller than the legacy max */
assert(max_udp_size >= DNS_PACKET_UNICAST_SIZE_MAX);
+ assert(rcode >= 0);
+ assert(rcode <= _DNS_RCODE_MAX);
if (p->opt_start != (size_t) -1)
return -EBUSY;
if (r < 0)
goto fail;
- /* maximum udp packet that can be received */
+ /* class: maximum udp packet that can be received */
r = dns_packet_append_uint16(p, max_udp_size, NULL);
if (r < 0)
goto fail;
/* extended RCODE and VERSION */
- r = dns_packet_append_uint16(p, 0, NULL);
+ r = dns_packet_append_uint16(p, ((uint16_t) rcode & 0x0FF0) << 4, NULL);
if (r < 0)
goto fail;
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, size_t *rdata_start);
-int dns_packet_append_opt(DnsPacket *p, uint16_t max_udp_size, bool edns0_do, size_t *start);
+int dns_packet_append_opt(DnsPacket *p, uint16_t max_udp_size, bool edns0_do, int rcode, size_t *start);
int dns_packet_append_question(DnsPacket *p, DnsQuestion *q);
int dns_packet_append_answer(DnsPacket *p, DnsAnswer *a);
DNS_RCODE_BADNAME = 20,
DNS_RCODE_BADALG = 21,
DNS_RCODE_BADTRUNC = 22,
- _DNS_RCODE_MAX_DEFINED
+ _DNS_RCODE_MAX_DEFINED,
+ _DNS_RCODE_MAX = 4095 /* 4 bit rcode in the header plus 8 bit rcode in OPT, makes 12 bit */
};
const char* dns_rcode_to_string(int i) _const_;
else
packet_size = server->received_udp_packet_max;
- return dns_packet_append_opt(packet, packet_size, edns_do, NULL);
+ return dns_packet_append_opt(packet, packet_size, edns_do, 0, NULL);
}
int dns_server_ifindex(const DnsServer *s) {