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path: root/src/resolve/resolved-dns-stub.c
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Diffstat (limited to 'src/resolve/resolved-dns-stub.c')
-rw-r--r--src/resolve/resolved-dns-stub.c161
1 files changed, 101 insertions, 60 deletions
diff --git a/src/resolve/resolved-dns-stub.c b/src/resolve/resolved-dns-stub.c
index 4a3c5f612f..7afbfedfb0 100644
--- a/src/resolve/resolved-dns-stub.c
+++ b/src/resolve/resolved-dns-stub.c
@@ -29,49 +29,33 @@ static int manager_dns_stub_udp_fd(Manager *m);
static int manager_dns_stub_tcp_fd(Manager *m);
static int dns_stub_make_reply_packet(
- uint16_t id,
- int rcode,
+ DnsPacket **p,
DnsQuestion *q,
- DnsAnswer *answer,
- bool add_opt, /* add an OPT RR to this packet */
- bool edns0_do, /* set the EDNS0 DNSSEC OK bit */
- bool ad, /* set the DNSSEC authenticated data bit */
- DnsPacket **ret) {
+ DnsAnswer *answer) {
- _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
DnsResourceRecord *rr;
unsigned c = 0;
int r;
+ assert(p);
+
/* Note that we don't bother with any additional RRs, as this is stub is for local lookups only, and hence
* roundtrips aren't expensive. */
- r = dns_packet_new(&p, DNS_PROTOCOL_DNS, 0);
- if (r < 0)
- return r;
-
- /* If the client didn't do EDNS, clamp the rcode to 4 bit */
- if (!add_opt && rcode > 0xF)
- rcode = DNS_RCODE_SERVFAIL;
+ if (!*p) {
+ r = dns_packet_new(p, DNS_PROTOCOL_DNS, 0);
+ if (r < 0)
+ return r;
- DNS_PACKET_HEADER(p)->id = id;
- DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS(
- 1 /* qr */,
- 0 /* opcode */,
- 0 /* aa */,
- 0 /* tc */,
- 1 /* rd */,
- 1 /* ra */,
- ad /* ad */,
- 0 /* cd */,
- rcode));
+ r = dns_packet_append_question(*p, q);
+ if (r < 0)
+ return r;
- r = dns_packet_append_question(p, q);
- if (r < 0)
- return r;
- DNS_PACKET_HEADER(p)->qdcount = htobe16(dns_question_size(q));
+ DNS_PACKET_HEADER(*p)->qdcount = htobe16(dns_question_size(q));
+ }
DNS_ANSWER_FOREACH(rr, answer) {
+
r = dns_question_matches_rr(q, rr, NULL);
if (r < 0)
return r;
@@ -86,13 +70,55 @@ static int dns_stub_make_reply_packet(
continue;
add:
- r = dns_packet_append_rr(p, rr, NULL, NULL);
+ r = dns_packet_append_rr(*p, rr, 0, NULL, NULL);
if (r < 0)
return r;
c++;
}
- DNS_PACKET_HEADER(p)->ancount = htobe16(c);
+
+ DNS_PACKET_HEADER(*p)->ancount = htobe16(be16toh(DNS_PACKET_HEADER(*p)->ancount) + c);
+
+ return 0;
+}
+
+static int dns_stub_finish_reply_packet(
+ DnsPacket *p,
+ uint16_t id,
+ int rcode,
+ bool add_opt, /* add an OPT RR to this packet? */
+ bool edns0_do, /* set the EDNS0 DNSSEC OK bit? */
+ bool ad) { /* set the DNSSEC authenticated data bit? */
+
+ int r;
+
+ assert(p);
+
+ if (!add_opt) {
+ /* If the client can't to EDNS0, don't do DO either */
+ edns0_do = false;
+
+ /* If the client didn't do EDNS, clamp the rcode to 4 bit */
+ if (rcode > 0xF)
+ rcode = DNS_RCODE_SERVFAIL;
+ }
+
+ /* Don't set the AD bit unless DO is on, too */
+ if (!edns0_do)
+ ad = false;
+
+ DNS_PACKET_HEADER(p)->id = id;
+
+ DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS(
+ 1 /* qr */,
+ 0 /* opcode */,
+ 0 /* aa */,
+ 0 /* tc */,
+ 1 /* rd */,
+ 1 /* ra */,
+ ad /* ad */,
+ 0 /* cd */,
+ rcode));
if (add_opt) {
r = dns_packet_append_opt(p, ADVERTISE_DATAGRAM_SIZE_MAX, edns0_do, rcode, NULL);
@@ -100,9 +126,6 @@ static int dns_stub_make_reply_packet(
return r;
}
- *ret = p;
- p = NULL;
-
return 0;
}
@@ -148,14 +171,18 @@ static int dns_stub_send(Manager *m, DnsStream *s, DnsPacket *p, DnsPacket *repl
return 0;
}
-static int dns_stub_send_failure(Manager *m, DnsStream *s, DnsPacket *p, int rcode) {
+static int dns_stub_send_failure(Manager *m, DnsStream *s, DnsPacket *p, int rcode, bool authenticated) {
_cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL;
int r;
assert(m);
assert(p);
- r = dns_stub_make_reply_packet(DNS_PACKET_ID(p), rcode, p->question, NULL, !!p->opt, DNS_PACKET_DO(p), false, &reply);
+ r = dns_stub_make_reply_packet(&reply, p->question, NULL);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to make failure packet: %m");
+
+ r = dns_stub_finish_reply_packet(reply, DNS_PACKET_ID(p), rcode, !!p->opt, DNS_PACKET_DO(p), authenticated);
if (r < 0)
return log_debug_errno(r, "Failed to build failure packet: %m");
@@ -170,33 +197,47 @@ static void dns_stub_query_complete(DnsQuery *q) {
switch (q->state) {
- case DNS_TRANSACTION_SUCCESS: {
- _cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL;
+ case DNS_TRANSACTION_SUCCESS:
+
+ r = dns_stub_make_reply_packet(&q->reply_dns_packet, q->question_idna, q->answer);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to build reply packet: %m");
+ break;
+ }
- r = dns_stub_make_reply_packet(
+ r = dns_query_process_cname(q);
+ if (r == -ELOOP) {
+ (void) dns_stub_send_failure(q->manager, q->request_dns_stream, q->request_dns_packet, DNS_RCODE_SERVFAIL, false);
+ break;
+ }
+ if (r < 0) {
+ log_debug_errno(r, "Failed to process CNAME: %m");
+ break;
+ }
+ if (r == DNS_QUERY_RESTARTED)
+ return;
+
+ r = dns_stub_finish_reply_packet(
+ q->reply_dns_packet,
DNS_PACKET_ID(q->request_dns_packet),
q->answer_rcode,
- q->question_idna,
- q->answer,
!!q->request_dns_packet->opt,
DNS_PACKET_DO(q->request_dns_packet),
- DNS_PACKET_DO(q->request_dns_packet) && q->answer_authenticated,
- &reply);
+ dns_query_fully_authenticated(q));
if (r < 0) {
- log_debug_errno(r, "Failed to build reply packet: %m");
+ log_debug_errno(r, "Failed to finish reply packet: %m");
break;
}
- (void) dns_stub_send(q->manager, q->request_dns_stream, q->request_dns_packet, reply);
+ (void) dns_stub_send(q->manager, q->request_dns_stream, q->request_dns_packet, q->reply_dns_packet);
break;
- }
case DNS_TRANSACTION_RCODE_FAILURE:
- (void) dns_stub_send_failure(q->manager, q->request_dns_stream, q->request_dns_packet, q->answer_rcode);
+ (void) dns_stub_send_failure(q->manager, q->request_dns_stream, q->request_dns_packet, q->answer_rcode, dns_query_fully_authenticated(q));
break;
case DNS_TRANSACTION_NOT_FOUND:
- (void) dns_stub_send_failure(q->manager, q->request_dns_stream, q->request_dns_packet, DNS_RCODE_NXDOMAIN);
+ (void) dns_stub_send_failure(q->manager, q->request_dns_stream, q->request_dns_packet, DNS_RCODE_NXDOMAIN, dns_query_fully_authenticated(q));
break;
case DNS_TRANSACTION_TIMEOUT:
@@ -212,7 +253,7 @@ static void dns_stub_query_complete(DnsQuery *q) {
case DNS_TRANSACTION_NO_TRUST_ANCHOR:
case DNS_TRANSACTION_RR_TYPE_UNSUPPORTED:
case DNS_TRANSACTION_NETWORK_DOWN:
- (void) dns_stub_send_failure(q->manager, q->request_dns_stream, q->request_dns_packet, DNS_RCODE_SERVFAIL);
+ (void) dns_stub_send_failure(q->manager, q->request_dns_stream, q->request_dns_packet, DNS_RCODE_SERVFAIL, false);
break;
case DNS_TRANSACTION_NULL:
@@ -259,52 +300,52 @@ static void dns_stub_process_query(Manager *m, DnsStream *s, DnsPacket *p) {
if (in_addr_is_localhost(p->family, &p->sender) <= 0 ||
in_addr_is_localhost(p->family, &p->destination) <= 0) {
log_error("Got packet on unexpected IP range, refusing.");
- dns_stub_send_failure(m, s, p, DNS_RCODE_SERVFAIL);
+ dns_stub_send_failure(m, s, p, DNS_RCODE_SERVFAIL, false);
goto fail;
}
r = dns_packet_extract(p);
if (r < 0) {
log_debug_errno(r, "Failed to extract resources from incoming packet, ignoring packet: %m");
- dns_stub_send_failure(m, s, p, DNS_RCODE_FORMERR);
+ dns_stub_send_failure(m, s, p, DNS_RCODE_FORMERR, false);
goto fail;
}
if (!DNS_PACKET_VERSION_SUPPORTED(p)) {
log_debug("Got EDNS OPT field with unsupported version number.");
- dns_stub_send_failure(m, s, p, DNS_RCODE_BADVERS);
+ dns_stub_send_failure(m, s, p, DNS_RCODE_BADVERS, false);
goto fail;
}
if (dns_type_is_obsolete(p->question->keys[0]->type)) {
log_debug("Got message with obsolete key type, refusing.");
- dns_stub_send_failure(m, s, p, DNS_RCODE_NOTIMP);
+ dns_stub_send_failure(m, s, p, DNS_RCODE_NOTIMP, false);
goto fail;
}
if (dns_type_is_zone_transer(p->question->keys[0]->type)) {
log_debug("Got request for zone transfer, refusing.");
- dns_stub_send_failure(m, s, p, DNS_RCODE_NOTIMP);
+ dns_stub_send_failure(m, s, p, DNS_RCODE_NOTIMP, false);
goto fail;
}
if (!DNS_PACKET_RD(p)) {
/* If the "rd" bit is off (i.e. recursion was not requested), then refuse operation */
log_debug("Got request with recursion disabled, refusing.");
- dns_stub_send_failure(m, s, p, DNS_RCODE_REFUSED);
+ dns_stub_send_failure(m, s, p, DNS_RCODE_REFUSED, false);
goto fail;
}
if (DNS_PACKET_DO(p) && DNS_PACKET_CD(p)) {
log_debug("Got request with DNSSEC CD bit set, refusing.");
- dns_stub_send_failure(m, s, p, DNS_RCODE_NOTIMP);
+ dns_stub_send_failure(m, s, p, DNS_RCODE_NOTIMP, false);
goto fail;
}
- r = dns_query_new(m, &q, p->question, p->question, 0, SD_RESOLVED_PROTOCOLS_ALL|SD_RESOLVED_NO_SEARCH|SD_RESOLVED_NO_CNAME);
+ r = dns_query_new(m, &q, p->question, p->question, 0, SD_RESOLVED_PROTOCOLS_ALL|SD_RESOLVED_NO_SEARCH);
if (r < 0) {
log_error_errno(r, "Failed to generate query object: %m");
- dns_stub_send_failure(m, s, p, DNS_RCODE_SERVFAIL);
+ dns_stub_send_failure(m, s, p, DNS_RCODE_SERVFAIL, false);
goto fail;
}
@@ -324,7 +365,7 @@ static void dns_stub_process_query(Manager *m, DnsStream *s, DnsPacket *p) {
r = dns_query_go(q);
if (r < 0) {
log_error_errno(r, "Failed to start query: %m");
- dns_stub_send_failure(m, s, p, DNS_RCODE_SERVFAIL);
+ dns_stub_send_failure(m, s, p, DNS_RCODE_SERVFAIL, false);
goto fail;
}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-09-07 09:54:30 +0000