777 lines
27 KiB
C
777 lines
27 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
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#include <net/if_arp.h>
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#include "errno-util.h"
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#include "fd-util.h"
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#include "missing_network.h"
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#include "missing_socket.h"
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#include "resolved-dns-stub.h"
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#include "socket-netlink.h"
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#include "socket-util.h"
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#include "string-table.h"
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/* The MTU of the loopback device is 64K on Linux, advertise that as maximum datagram size, but subtract the Ethernet,
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* IP and UDP header sizes */
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#define ADVERTISE_DATAGRAM_SIZE_MAX (65536U-14U-20U-8U)
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/* On the extra stubs, use a more conservative choice */
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#define ADVERTISE_EXTRA_DATAGRAM_SIZE_MAX DNS_PACKET_UNICAST_SIZE_LARGE_MAX
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static int manager_dns_stub_fd_extra(Manager *m, DnsStubListenerExtra *l, int type);
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static void dns_stub_listener_extra_hash_func(const DnsStubListenerExtra *a, struct siphash *state) {
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assert(a);
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siphash24_compress(&a->mode, sizeof(a->mode), state);
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siphash24_compress(&a->family, sizeof(a->family), state);
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siphash24_compress(&a->address, FAMILY_ADDRESS_SIZE(a->family), state);
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siphash24_compress(&a->port, sizeof(a->port), state);
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}
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static int dns_stub_listener_extra_compare_func(const DnsStubListenerExtra *a, const DnsStubListenerExtra *b) {
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int r;
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assert(a);
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assert(b);
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r = CMP(a->mode, b->mode);
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if (r != 0)
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return r;
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r = CMP(a->family, b->family);
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if (r != 0)
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return r;
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r = memcmp(&a->address, &b->address, FAMILY_ADDRESS_SIZE(a->family));
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if (r != 0)
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return r;
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return CMP(a->port, b->port);
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}
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DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(
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dns_stub_listener_extra_hash_ops,
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DnsStubListenerExtra,
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dns_stub_listener_extra_hash_func,
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dns_stub_listener_extra_compare_func,
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dns_stub_listener_extra_free);
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int dns_stub_listener_extra_new(
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Manager *m,
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DnsStubListenerExtra **ret) {
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DnsStubListenerExtra *l;
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l = new(DnsStubListenerExtra, 1);
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if (!l)
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return -ENOMEM;
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*l = (DnsStubListenerExtra) {
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.manager = m,
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};
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*ret = TAKE_PTR(l);
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return 0;
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}
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DnsStubListenerExtra *dns_stub_listener_extra_free(DnsStubListenerExtra *p) {
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if (!p)
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return NULL;
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p->udp_event_source = sd_event_source_unref(p->udp_event_source);
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p->tcp_event_source = sd_event_source_unref(p->tcp_event_source);
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return mfree(p);
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}
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static int dns_stub_make_reply_packet(
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DnsPacket **p,
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size_t max_size,
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DnsQuestion *q,
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DnsAnswer *answer,
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bool *ret_truncated) {
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bool truncated = false;
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DnsResourceRecord *rr;
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unsigned c = 0;
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int r;
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assert(p);
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/* Note that we don't bother with any additional RRs, as this is stub is for local lookups only, and hence
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* roundtrips aren't expensive. */
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if (!*p) {
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r = dns_packet_new(p, DNS_PROTOCOL_DNS, 0, max_size);
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if (r < 0)
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return r;
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r = dns_packet_append_question(*p, q);
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if (r < 0)
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return r;
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DNS_PACKET_HEADER(*p)->qdcount = htobe16(dns_question_size(q));
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}
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DNS_ANSWER_FOREACH(rr, answer) {
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r = dns_question_matches_rr(q, rr, NULL);
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if (r < 0)
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return r;
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if (r > 0)
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goto add;
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r = dns_question_matches_cname_or_dname(q, rr, NULL);
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if (r < 0)
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return r;
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if (r > 0)
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goto add;
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continue;
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add:
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r = dns_packet_append_rr(*p, rr, 0, NULL, NULL);
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if (r == -EMSGSIZE) {
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truncated = true;
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break;
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}
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if (r < 0)
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return r;
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c++;
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}
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if (ret_truncated)
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*ret_truncated = truncated;
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else if (truncated)
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return -EMSGSIZE;
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DNS_PACKET_HEADER(*p)->ancount = htobe16(be16toh(DNS_PACKET_HEADER(*p)->ancount) + c);
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return 0;
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}
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static int dns_stub_finish_reply_packet(
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DnsPacket *p,
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uint16_t id,
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int rcode,
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bool tc, /* set the Truncated bit? */
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bool add_opt, /* add an OPT RR to this packet? */
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bool edns0_do, /* set the EDNS0 DNSSEC OK bit? */
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bool ad, /* set the DNSSEC authenticated data bit? */
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uint16_t max_udp_size) { /* The maximum UDP datagram size to advertise to clients */
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int r;
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assert(p);
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if (add_opt) {
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r = dns_packet_append_opt(p, max_udp_size, edns0_do, /* include_rfc6975 = */ false, rcode, NULL);
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if (r == -EMSGSIZE) /* Hit the size limit? then indicate truncation */
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tc = true;
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else if (r < 0)
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return r;
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} else {
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/* If the client can't to EDNS0, don't do DO either */
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edns0_do = false;
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/* If the client didn't do EDNS, clamp the rcode to 4 bit */
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if (rcode > 0xF)
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rcode = DNS_RCODE_SERVFAIL;
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}
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/* Don't set the AD bit unless DO is on, too */
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if (!edns0_do)
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ad = false;
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DNS_PACKET_HEADER(p)->id = id;
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DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS(
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1 /* qr */,
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0 /* opcode */,
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0 /* aa */,
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tc /* tc */,
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1 /* rd */,
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1 /* ra */,
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ad /* ad */,
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0 /* cd */,
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rcode));
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return 0;
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}
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static int dns_stub_send(
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Manager *m,
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DnsStubListenerExtra *l,
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DnsStream *s,
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DnsPacket *p,
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DnsPacket *reply) {
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int r;
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assert(m);
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assert(p);
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assert(reply);
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if (s)
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r = dns_stream_write_packet(s, reply);
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else
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/* Note that it is essential here that we explicitly choose the source IP address for this packet. This
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* is because otherwise the kernel will choose it automatically based on the routing table and will
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* thus pick 127.0.0.1 rather than 127.0.0.53. */
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r = manager_send(m,
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manager_dns_stub_fd_extra(m, l, SOCK_DGRAM),
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l ? p->ifindex : LOOPBACK_IFINDEX, /* force loopback iface if this is the main listener stub */
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p->family, &p->sender, p->sender_port, &p->destination,
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reply);
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if (r < 0)
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return log_debug_errno(r, "Failed to send reply packet: %m");
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return 0;
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}
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static int dns_stub_send_failure(
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Manager *m,
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DnsStubListenerExtra *l,
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DnsStream *s,
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DnsPacket *p,
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int rcode,
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bool authenticated) {
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_cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL;
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int r;
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assert(m);
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assert(p);
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r = dns_stub_make_reply_packet(&reply, DNS_PACKET_PAYLOAD_SIZE_MAX(p), p->question, NULL, NULL);
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if (r < 0)
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return log_debug_errno(r, "Failed to make failure packet: %m");
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r = dns_stub_finish_reply_packet(
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reply,
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DNS_PACKET_ID(p),
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rcode,
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/* truncated = */ false,
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!!p->opt,
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DNS_PACKET_DO(p),
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authenticated,
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l ? ADVERTISE_EXTRA_DATAGRAM_SIZE_MAX : ADVERTISE_DATAGRAM_SIZE_MAX);
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if (r < 0)
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return log_debug_errno(r, "Failed to build failure packet: %m");
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return dns_stub_send(m, l, s, p, reply);
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}
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static void dns_stub_query_complete(DnsQuery *q) {
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int r;
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assert(q);
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assert(q->request_dns_packet);
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switch (q->state) {
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case DNS_TRANSACTION_SUCCESS: {
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bool truncated;
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r = dns_stub_make_reply_packet(&q->reply_dns_packet, DNS_PACKET_PAYLOAD_SIZE_MAX(q->request_dns_packet), q->question_idna, q->answer, &truncated);
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if (r < 0) {
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log_debug_errno(r, "Failed to build reply packet: %m");
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break;
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}
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if (!truncated) {
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r = dns_query_process_cname(q);
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if (r == -ELOOP) {
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(void) dns_stub_send_failure(q->manager, q->stub_listener_extra, q->request_dns_stream, q->request_dns_packet, DNS_RCODE_SERVFAIL, false);
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break;
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}
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if (r < 0) {
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log_debug_errno(r, "Failed to process CNAME: %m");
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break;
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}
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if (r == DNS_QUERY_RESTARTED)
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return;
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}
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r = dns_stub_finish_reply_packet(
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q->reply_dns_packet,
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DNS_PACKET_ID(q->request_dns_packet),
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q->answer_rcode,
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truncated,
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!!q->request_dns_packet->opt,
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DNS_PACKET_DO(q->request_dns_packet),
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dns_query_fully_authenticated(q),
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q->stub_listener_extra ? ADVERTISE_EXTRA_DATAGRAM_SIZE_MAX : ADVERTISE_DATAGRAM_SIZE_MAX);
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if (r < 0) {
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log_debug_errno(r, "Failed to finish reply packet: %m");
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break;
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}
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(void) dns_stub_send(q->manager, q->stub_listener_extra, q->request_dns_stream, q->request_dns_packet, q->reply_dns_packet);
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break;
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}
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case DNS_TRANSACTION_RCODE_FAILURE:
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(void) dns_stub_send_failure(q->manager, q->stub_listener_extra, q->request_dns_stream, q->request_dns_packet, q->answer_rcode, dns_query_fully_authenticated(q));
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break;
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case DNS_TRANSACTION_NOT_FOUND:
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(void) dns_stub_send_failure(q->manager, q->stub_listener_extra, q->request_dns_stream, q->request_dns_packet, DNS_RCODE_NXDOMAIN, dns_query_fully_authenticated(q));
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break;
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case DNS_TRANSACTION_TIMEOUT:
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case DNS_TRANSACTION_ATTEMPTS_MAX_REACHED:
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/* Propagate a timeout as a no packet, i.e. that the client also gets a timeout */
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break;
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case DNS_TRANSACTION_NO_SERVERS:
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case DNS_TRANSACTION_INVALID_REPLY:
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case DNS_TRANSACTION_ERRNO:
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case DNS_TRANSACTION_ABORTED:
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case DNS_TRANSACTION_DNSSEC_FAILED:
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case DNS_TRANSACTION_NO_TRUST_ANCHOR:
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case DNS_TRANSACTION_RR_TYPE_UNSUPPORTED:
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case DNS_TRANSACTION_NETWORK_DOWN:
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(void) dns_stub_send_failure(q->manager, q->stub_listener_extra, q->request_dns_stream, q->request_dns_packet, DNS_RCODE_SERVFAIL, false);
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break;
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case DNS_TRANSACTION_NULL:
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case DNS_TRANSACTION_PENDING:
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case DNS_TRANSACTION_VALIDATING:
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default:
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assert_not_reached("Impossible state");
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}
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dns_query_free(q);
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}
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static int dns_stub_stream_complete(DnsStream *s, int error) {
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assert(s);
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log_debug_errno(error, "DNS TCP connection terminated, destroying queries: %m");
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for (;;) {
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DnsQuery *q;
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q = set_first(s->queries);
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if (!q)
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break;
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dns_query_free(q);
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}
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/* This drops the implicit ref we keep around since it was allocated, as incoming stub connections
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* should be kept as long as the client wants to. */
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dns_stream_unref(s);
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return 0;
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}
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static void dns_stub_process_query(Manager *m, DnsStubListenerExtra *l, DnsStream *s, DnsPacket *p) {
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_cleanup_(dns_query_freep) DnsQuery *q = NULL;
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int r;
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assert(m);
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assert(p);
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assert(p->protocol == DNS_PROTOCOL_DNS);
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if (!l && /* l == NULL if this is the main stub */
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(in_addr_is_localhost(p->family, &p->sender) <= 0 ||
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in_addr_is_localhost(p->family, &p->destination) <= 0)) {
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log_warning("Got packet on unexpected (i.e. non-localhost) IP range, ignoring.");
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return;
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}
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r = dns_packet_extract(p);
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if (r < 0) {
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log_debug_errno(r, "Failed to extract resources from incoming packet, ignoring packet: %m");
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dns_stub_send_failure(m, l, s, p, DNS_RCODE_FORMERR, false);
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return;
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}
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if (!DNS_PACKET_VERSION_SUPPORTED(p)) {
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log_debug("Got EDNS OPT field with unsupported version number.");
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dns_stub_send_failure(m, l, s, p, DNS_RCODE_BADVERS, false);
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return;
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}
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if (dns_type_is_obsolete(p->question->keys[0]->type)) {
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log_debug("Got message with obsolete key type, refusing.");
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dns_stub_send_failure(m, l, s, p, DNS_RCODE_NOTIMP, false);
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return;
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}
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if (dns_type_is_zone_transer(p->question->keys[0]->type)) {
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log_debug("Got request for zone transfer, refusing.");
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dns_stub_send_failure(m, l, s, p, DNS_RCODE_NOTIMP, false);
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return;
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}
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if (!DNS_PACKET_RD(p)) {
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/* If the "rd" bit is off (i.e. recursion was not requested), then refuse operation */
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log_debug("Got request with recursion disabled, refusing.");
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dns_stub_send_failure(m, l, s, p, DNS_RCODE_REFUSED, false);
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return;
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}
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if (DNS_PACKET_DO(p) && DNS_PACKET_CD(p)) {
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log_debug("Got request with DNSSEC CD bit set, refusing.");
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dns_stub_send_failure(m, l, s, p, DNS_RCODE_NOTIMP, false);
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return;
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}
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r = dns_query_new(m, &q, p->question, p->question, 0, SD_RESOLVED_PROTOCOLS_ALL|SD_RESOLVED_NO_SEARCH);
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if (r < 0) {
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log_error_errno(r, "Failed to generate query object: %m");
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dns_stub_send_failure(m, l, s, p, DNS_RCODE_SERVFAIL, false);
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return;
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}
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/* Request that the TTL is corrected by the cached time for this lookup, so that we return vaguely useful TTLs */
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q->clamp_ttl = true;
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q->request_dns_packet = dns_packet_ref(p);
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q->request_dns_stream = dns_stream_ref(s); /* make sure the stream stays around until we can send a reply through it */
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q->stub_listener_extra = l;
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q->complete = dns_stub_query_complete;
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if (s) {
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/* Remember which queries belong to this stream, so that we can cancel them when the stream
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* is disconnected early */
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r = set_ensure_put(&s->queries, NULL, q);
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if (r < 0) {
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log_oom();
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return;
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}
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assert(r > 0);
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}
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r = dns_query_go(q);
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if (r < 0) {
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log_error_errno(r, "Failed to start query: %m");
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dns_stub_send_failure(m, l, s, p, DNS_RCODE_SERVFAIL, false);
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return;
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}
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log_debug("Processing query...");
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TAKE_PTR(q);
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}
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static int on_dns_stub_packet_internal(sd_event_source *s, int fd, uint32_t revents, Manager *m, DnsStubListenerExtra *l) {
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_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
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int r;
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r = manager_recv(m, fd, DNS_PROTOCOL_DNS, &p);
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if (r <= 0)
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return r;
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if (dns_packet_validate_query(p) > 0) {
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log_debug("Got DNS stub UDP query packet for id %u", DNS_PACKET_ID(p));
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dns_stub_process_query(m, l, NULL, p);
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} else
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log_debug("Invalid DNS stub UDP packet, ignoring.");
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return 0;
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}
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static int on_dns_stub_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
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return on_dns_stub_packet_internal(s, fd, revents, userdata, NULL);
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}
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static int on_dns_stub_packet_extra(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
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DnsStubListenerExtra *l = userdata;
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assert(l);
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return on_dns_stub_packet_internal(s, fd, revents, l->manager, l);
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}
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static int on_dns_stub_stream_packet(DnsStream *s) {
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_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
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|
|
assert(s);
|
|
|
|
p = dns_stream_take_read_packet(s);
|
|
assert(p);
|
|
|
|
if (dns_packet_validate_query(p) > 0) {
|
|
log_debug("Got DNS stub TCP query packet for id %u", DNS_PACKET_ID(p));
|
|
|
|
dns_stub_process_query(s->manager, s->stub_listener_extra, s, p);
|
|
} else
|
|
log_debug("Invalid DNS stub TCP packet, ignoring.");
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int on_dns_stub_stream_internal(sd_event_source *s, int fd, uint32_t revents, Manager *m, DnsStubListenerExtra *l) {
|
|
DnsStream *stream;
|
|
int cfd, r;
|
|
|
|
cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
|
|
if (cfd < 0) {
|
|
if (ERRNO_IS_ACCEPT_AGAIN(errno))
|
|
return 0;
|
|
|
|
return -errno;
|
|
}
|
|
|
|
r = dns_stream_new(m, &stream, DNS_STREAM_STUB, DNS_PROTOCOL_DNS, cfd, NULL);
|
|
if (r < 0) {
|
|
safe_close(cfd);
|
|
return r;
|
|
}
|
|
|
|
stream->stub_listener_extra = l;
|
|
stream->on_packet = on_dns_stub_stream_packet;
|
|
stream->complete = dns_stub_stream_complete;
|
|
|
|
/* We let the reference to the stream dangle here, it will be dropped later by the complete callback. */
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int on_dns_stub_stream(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
|
|
return on_dns_stub_stream_internal(s, fd, revents, userdata, NULL);
|
|
}
|
|
|
|
static int on_dns_stub_stream_extra(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
|
|
DnsStubListenerExtra *l = userdata;
|
|
|
|
assert(l);
|
|
return on_dns_stub_stream_internal(s, fd, revents, l->manager, l);
|
|
}
|
|
|
|
static int set_dns_stub_common_socket_options(int fd, int family) {
|
|
int r;
|
|
|
|
assert(fd >= 0);
|
|
assert(IN_SET(family, AF_INET, AF_INET6));
|
|
|
|
r = setsockopt_int(fd, SOL_SOCKET, SO_REUSEADDR, true);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = socket_set_recvpktinfo(fd, family, true);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = socket_set_recvttl(fd, family, true);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int manager_dns_stub_fd(Manager *m, int type) {
|
|
union sockaddr_union sa = {
|
|
.in.sin_family = AF_INET,
|
|
.in.sin_addr.s_addr = htobe32(INADDR_DNS_STUB),
|
|
.in.sin_port = htobe16(53),
|
|
};
|
|
_cleanup_close_ int fd = -1;
|
|
int r;
|
|
|
|
assert(IN_SET(type, SOCK_DGRAM, SOCK_STREAM));
|
|
|
|
sd_event_source **event_source = type == SOCK_DGRAM ? &m->dns_stub_udp_event_source : &m->dns_stub_tcp_event_source;
|
|
if (*event_source)
|
|
return sd_event_source_get_io_fd(*event_source);
|
|
|
|
fd = socket(AF_INET, type | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
|
|
if (fd < 0)
|
|
return -errno;
|
|
|
|
r = set_dns_stub_common_socket_options(fd, AF_INET);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
/* Make sure no traffic from outside the local host can leak to onto this socket */
|
|
r = socket_bind_to_ifindex(fd, LOOPBACK_IFINDEX);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = setsockopt_int(fd, IPPROTO_IP, IP_TTL, 1);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
if (bind(fd, &sa.sa, sizeof(sa.in)) < 0)
|
|
return -errno;
|
|
|
|
if (type == SOCK_STREAM &&
|
|
listen(fd, SOMAXCONN) < 0)
|
|
return -errno;
|
|
|
|
r = sd_event_add_io(m->event, event_source, fd, EPOLLIN,
|
|
type == SOCK_DGRAM ? on_dns_stub_packet : on_dns_stub_stream,
|
|
m);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = sd_event_source_set_io_fd_own(*event_source, true);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
(void) sd_event_source_set_description(*event_source,
|
|
type == SOCK_DGRAM ? "dns-stub-udp" : "dns-stub-tcp");
|
|
|
|
return TAKE_FD(fd);
|
|
}
|
|
|
|
static int manager_dns_stub_fd_extra(Manager *m, DnsStubListenerExtra *l, int type) {
|
|
_cleanup_free_ char *pretty = NULL;
|
|
_cleanup_close_ int fd = -1;
|
|
union sockaddr_union sa;
|
|
int r;
|
|
|
|
assert(m);
|
|
assert(IN_SET(type, SOCK_DGRAM, SOCK_STREAM));
|
|
|
|
if (!l)
|
|
return manager_dns_stub_fd(m, type);
|
|
|
|
sd_event_source **event_source = type == SOCK_DGRAM ? &l->udp_event_source : &l->tcp_event_source;
|
|
if (*event_source)
|
|
return sd_event_source_get_io_fd(*event_source);
|
|
|
|
if (l->family == AF_INET)
|
|
sa = (union sockaddr_union) {
|
|
.in.sin_family = l->family,
|
|
.in.sin_port = htobe16(l->port != 0 ? l->port : 53U),
|
|
.in.sin_addr = l->address.in,
|
|
};
|
|
else
|
|
sa = (union sockaddr_union) {
|
|
.in6.sin6_family = l->family,
|
|
.in6.sin6_port = htobe16(l->port != 0 ? l->port : 53U),
|
|
.in6.sin6_addr = l->address.in6,
|
|
};
|
|
|
|
fd = socket(l->family, type | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
|
|
if (fd < 0) {
|
|
r = -errno;
|
|
goto fail;
|
|
}
|
|
|
|
r = set_dns_stub_common_socket_options(fd, l->family);
|
|
if (r < 0)
|
|
goto fail;
|
|
|
|
/* Do not set IP_TTL for extra DNS stub listeners, as the address may not be local and in that case
|
|
* people may want ttl > 1. */
|
|
|
|
r = socket_set_freebind(fd, l->family, true);
|
|
if (r < 0)
|
|
goto fail;
|
|
|
|
if (bind(fd, &sa.sa, SOCKADDR_LEN(sa)) < 0) {
|
|
r = -errno;
|
|
goto fail;
|
|
}
|
|
|
|
if (type == SOCK_STREAM &&
|
|
listen(fd, SOMAXCONN) < 0) {
|
|
r = -errno;
|
|
goto fail;
|
|
}
|
|
|
|
r = sd_event_add_io(m->event, event_source, fd, EPOLLIN,
|
|
type == SOCK_DGRAM ? on_dns_stub_packet_extra : on_dns_stub_stream_extra,
|
|
l);
|
|
if (r < 0)
|
|
goto fail;
|
|
|
|
r = sd_event_source_set_io_fd_own(*event_source, true);
|
|
if (r < 0)
|
|
goto fail;
|
|
|
|
(void) sd_event_source_set_description(*event_source,
|
|
type == SOCK_DGRAM ? "dns-stub-udp-extra" : "dns-stub-tcp-extra");
|
|
|
|
if (DEBUG_LOGGING) {
|
|
(void) in_addr_port_to_string(l->family, &l->address, l->port, &pretty);
|
|
log_debug("Listening on %s socket %s.",
|
|
type == SOCK_DGRAM ? "UDP" : "TCP",
|
|
strnull(pretty));
|
|
}
|
|
|
|
return TAKE_FD(fd);
|
|
|
|
fail:
|
|
assert(r < 0);
|
|
(void) in_addr_port_to_string(l->family, &l->address, l->port, &pretty);
|
|
return log_warning_errno(r,
|
|
r == -EADDRINUSE ? "Another process is already listening on %s socket %s: %m" :
|
|
"Failed to listen on %s socket %s: %m",
|
|
type == SOCK_DGRAM ? "UDP" : "TCP",
|
|
strnull(pretty));
|
|
}
|
|
|
|
int manager_dns_stub_start(Manager *m) {
|
|
const char *t = "UDP";
|
|
int r = 0;
|
|
|
|
assert(m);
|
|
|
|
if (m->dns_stub_listener_mode == DNS_STUB_LISTENER_NO)
|
|
log_debug("Not creating stub listener.");
|
|
else
|
|
log_debug("Creating stub listener using %s.",
|
|
m->dns_stub_listener_mode == DNS_STUB_LISTENER_UDP ? "UDP" :
|
|
m->dns_stub_listener_mode == DNS_STUB_LISTENER_TCP ? "TCP" :
|
|
"UDP/TCP");
|
|
|
|
if (FLAGS_SET(m->dns_stub_listener_mode, DNS_STUB_LISTENER_UDP))
|
|
r = manager_dns_stub_fd(m, SOCK_DGRAM);
|
|
|
|
if (r >= 0 &&
|
|
FLAGS_SET(m->dns_stub_listener_mode, DNS_STUB_LISTENER_TCP)) {
|
|
t = "TCP";
|
|
r = manager_dns_stub_fd(m, SOCK_STREAM);
|
|
}
|
|
|
|
if (IN_SET(r, -EADDRINUSE, -EPERM)) {
|
|
log_warning_errno(r,
|
|
r == -EADDRINUSE ? "Another process is already listening on %s socket 127.0.0.53:53.\n"
|
|
"Turning off local DNS stub support." :
|
|
"Failed to listen on %s socket 127.0.0.53:53: %m.\n"
|
|
"Turning off local DNS stub support.",
|
|
t);
|
|
manager_dns_stub_stop(m);
|
|
} else if (r < 0)
|
|
return log_error_errno(r, "Failed to listen on %s socket 127.0.0.53:53: %m", t);
|
|
|
|
if (!ordered_set_isempty(m->dns_extra_stub_listeners)) {
|
|
DnsStubListenerExtra *l;
|
|
|
|
log_debug("Creating extra stub listeners.");
|
|
|
|
ORDERED_SET_FOREACH(l, m->dns_extra_stub_listeners) {
|
|
if (FLAGS_SET(l->mode, DNS_STUB_LISTENER_UDP))
|
|
(void) manager_dns_stub_fd_extra(m, l, SOCK_DGRAM);
|
|
if (FLAGS_SET(l->mode, DNS_STUB_LISTENER_TCP))
|
|
(void) manager_dns_stub_fd_extra(m, l, SOCK_STREAM);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void manager_dns_stub_stop(Manager *m) {
|
|
assert(m);
|
|
|
|
m->dns_stub_udp_event_source = sd_event_source_unref(m->dns_stub_udp_event_source);
|
|
m->dns_stub_tcp_event_source = sd_event_source_unref(m->dns_stub_tcp_event_source);
|
|
}
|
|
|
|
static const char* const dns_stub_listener_mode_table[_DNS_STUB_LISTENER_MODE_MAX] = {
|
|
[DNS_STUB_LISTENER_NO] = "no",
|
|
[DNS_STUB_LISTENER_UDP] = "udp",
|
|
[DNS_STUB_LISTENER_TCP] = "tcp",
|
|
[DNS_STUB_LISTENER_YES] = "yes",
|
|
};
|
|
DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(dns_stub_listener_mode, DnsStubListenerMode, DNS_STUB_LISTENER_YES);
|