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-rw-r--r--src/resolve/resolved-dns-scope.c98
-rw-r--r--src/resolve/resolved-dns-scope.h5
-rw-r--r--src/resolve/resolved-dns-transaction.c8
-rw-r--r--src/resolve/resolved-dns-transaction.h14
-rw-r--r--src/resolve/resolved-dns-zone.c1
-rw-r--r--src/resolve/resolved-mdns.h1
6 files changed, 118 insertions, 9 deletions
diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index 2c23a0df77..6616bc4e0e 100644
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -124,6 +124,8 @@ DnsScope* dns_scope_free(DnsScope *s) {
ordered_hashmap_free(s->conflict_queue);
sd_event_source_unref(s->conflict_event_source);
+ sd_event_source_unref(s->announce_event_source);
+
dns_cache_flush(&s->cache);
dns_zone_flush(&s->zone);
@@ -791,8 +793,15 @@ DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsResourceKey *key,
/* Try to find an ongoing transaction that is a equal to the
* specified question */
t = hashmap_get(scope->transactions_by_key, key);
- if (!t)
- return NULL;
+ if (!t) {
+ DnsResourceKey *key_any;
+
+ key_any = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_ANY, dns_resource_key_name(key));
+ t = hashmap_get(scope->transactions_by_key, key_any);
+ key_any = dns_resource_key_unref(key_any);
+ if (!t)
+ return NULL;
+ }
/* Refuse reusing transactions that completed based on cached
* data instead of a real packet, if that's requested. */
@@ -936,17 +945,19 @@ void dns_scope_check_conflicts(DnsScope *scope, DnsPacket *p) {
assert(scope);
assert(p);
- if (p->protocol != DNS_PROTOCOL_LLMNR)
+ if (!IN_SET(p->protocol, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS))
return;
if (DNS_PACKET_RRCOUNT(p) <= 0)
return;
- if (DNS_PACKET_LLMNR_C(p) != 0)
- return;
+ if (p->protocol == DNS_PROTOCOL_LLMNR) {
+ if (DNS_PACKET_LLMNR_C(p) != 0)
+ return;
- if (DNS_PACKET_LLMNR_T(p) != 0)
- return;
+ if (DNS_PACKET_LLMNR_T(p) != 0)
+ return;
+ }
if (manager_our_packet(scope->manager, p))
return;
@@ -1049,3 +1060,76 @@ int dns_scope_ifindex(DnsScope *s) {
return 0;
}
+
+static int on_announcement_timeout(sd_event_source *s, usec_t usec, void *userdata) {
+ DnsScope *scope = userdata;
+
+ assert(s);
+
+ scope->announce_event_source = sd_event_source_unref(scope->announce_event_source);
+
+ dns_scope_announce(scope);
+ return 0;
+}
+
+void dns_scope_announce(DnsScope *scope) {
+ _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
+ _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
+ LinkAddress *a;
+ int r;
+
+ if (!scope)
+ return;
+
+ if (scope->protocol != DNS_PROTOCOL_MDNS)
+ return;
+
+ answer = dns_answer_new(4);
+ LIST_FOREACH(addresses, a, scope->link->addresses) {
+ r = dns_answer_add(answer, a->mdns_address_rr, 0);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to add address RR to answer: %m");
+ return;
+ }
+ r = dns_answer_add(answer, a->mdns_ptr_rr, 0);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to add PTR RR to answer: %m");
+ return;
+ }
+ }
+
+ if (dns_answer_isempty(answer))
+ return;
+
+ r = dns_scope_make_reply_packet(scope, 0, DNS_RCODE_SUCCESS, NULL, answer, NULL, false, &p);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to build reply packet: %m");
+ return;
+ }
+ r = dns_scope_emit_udp(scope, -1, p);
+ if (r < 0) {
+ log_debug_errno(r, "Failed to send reply packet: %m");
+ return;
+ }
+
+ /* In section 8.3 of RFC6762: "The Multicast DNS responder MUST send at least two unsolicited
+ * responses, one second apart." */
+ if (!scope->announced) {
+ usec_t ts;
+
+ scope->announced = true;
+
+ assert_se(sd_event_now(scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0);
+ ts += MDNS_ANNOUNCE_DELAY;
+
+ r = sd_event_add_time(
+ scope->manager->event,
+ &scope->announce_event_source,
+ clock_boottime_or_monotonic(),
+ ts,
+ MDNS_JITTER_RANGE_USEC,
+ on_announcement_timeout, scope);
+ if (r < 0)
+ log_debug_errno(r, "Failed to schedule second announcement: %m");
+ }
+}
diff --git a/src/resolve/resolved-dns-scope.h b/src/resolve/resolved-dns-scope.h
index d501835e45..65b61c56aa 100644
--- a/src/resolve/resolved-dns-scope.h
+++ b/src/resolve/resolved-dns-scope.h
@@ -56,6 +56,9 @@ struct DnsScope {
OrderedHashmap *conflict_queue;
sd_event_source *conflict_event_source;
+ bool announced:1;
+ sd_event_source *announce_event_source;
+
RateLimit ratelimit;
usec_t resend_timeout;
@@ -113,3 +116,5 @@ bool dns_scope_name_needs_search_domain(DnsScope *s, const char *name);
bool dns_scope_network_good(DnsScope *s);
int dns_scope_ifindex(DnsScope *s);
+
+void dns_scope_announce(DnsScope *scope);
diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c
index 03d25dd984..bd36e5e1a1 100644
--- a/src/resolve/resolved-dns-transaction.c
+++ b/src/resolve/resolved-dns-transaction.c
@@ -363,6 +363,9 @@ void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state) {
SET_FOREACH_MOVE(z, t->notify_zone_items_done, t->notify_zone_items)
dns_zone_item_notify(z);
SWAP_TWO(t->notify_zone_items, t->notify_zone_items_done);
+ if (t->probing) {
+ dns_scope_announce(t->scope);
+ }
SET_FOREACH_MOVE(d, t->notify_transactions_done, t->notify_transactions)
dns_transaction_notify(d, t);
@@ -1209,7 +1212,10 @@ static usec_t transaction_get_resend_timeout(DnsTransaction *t) {
case DNS_PROTOCOL_MDNS:
assert(t->n_attempts > 0);
- return (1 << (t->n_attempts - 1)) * USEC_PER_SEC;
+ if (t->probing)
+ return MDNS_PROBING_INTERVAL_USEC;
+ else
+ return (1 << (t->n_attempts - 1)) * USEC_PER_SEC;
case DNS_PROTOCOL_LLMNR:
return t->scope->resend_timeout;
diff --git a/src/resolve/resolved-dns-transaction.h b/src/resolve/resolved-dns-transaction.h
index 5a1df70422..c4fb51958d 100644
--- a/src/resolve/resolved-dns-transaction.h
+++ b/src/resolve/resolved-dns-transaction.h
@@ -78,6 +78,8 @@ struct DnsTransaction {
bool clamp_ttl:1;
+ bool probing:1;
+
DnsPacket *sent, *received;
DnsAnswer *answer;
@@ -172,10 +174,20 @@ DnsTransactionSource dns_transaction_source_from_string(const char *s) _pure_;
#define MDNS_JITTER_MIN_USEC (20 * USEC_PER_MSEC)
#define MDNS_JITTER_RANGE_USEC (100 * USEC_PER_MSEC)
+/* mDNS probing interval, see RFC 6762 Section 8.1 */
+#define MDNS_PROBING_INTERVAL_USEC (250 * USEC_PER_MSEC)
+
/* Maximum attempts to send DNS requests, across all DNS servers */
#define DNS_TRANSACTION_ATTEMPTS_MAX 16
/* Maximum attempts to send LLMNR requests, see RFC 4795 Section 2.7 */
#define LLMNR_TRANSACTION_ATTEMPTS_MAX 3
-#define TRANSACTION_ATTEMPTS_MAX(p) ((p) == DNS_PROTOCOL_LLMNR ? LLMNR_TRANSACTION_ATTEMPTS_MAX : DNS_TRANSACTION_ATTEMPTS_MAX)
+/* Maximum attempts to send MDNS requests, see RFC 6762 Section 8.1 */
+#define MDNS_TRANSACTION_ATTEMPTS_MAX 3
+
+#define TRANSACTION_ATTEMPTS_MAX(p) (((p) == DNS_PROTOCOL_LLMNR) ? \
+ LLMNR_TRANSACTION_ATTEMPTS_MAX : \
+ (((p) == DNS_PROTOCOL_MDNS) ? \
+ MDNS_TRANSACTION_ATTEMPTS_MAX : \
+ DNS_TRANSACTION_ATTEMPTS_MAX))
diff --git a/src/resolve/resolved-dns-zone.c b/src/resolve/resolved-dns-zone.c
index 746a979f47..ad024b54f5 100644
--- a/src/resolve/resolved-dns-zone.c
+++ b/src/resolve/resolved-dns-zone.c
@@ -196,6 +196,7 @@ static int dns_zone_item_probe_start(DnsZoneItem *i) {
goto gc;
i->probe_transaction = t;
+ t->probing = true;
if (t->state == DNS_TRANSACTION_NULL) {
diff --git a/src/resolve/resolved-mdns.h b/src/resolve/resolved-mdns.h
index 5d274648f4..06bd3296be 100644
--- a/src/resolve/resolved-mdns.h
+++ b/src/resolve/resolved-mdns.h
@@ -22,6 +22,7 @@
#include "resolved-manager.h"
#define MDNS_PORT 5353
+#define MDNS_ANNOUNCE_DELAY (1 * USEC_PER_SEC)
int manager_mdns_ipv4_fd(Manager *m);
int manager_mdns_ipv6_fd(Manager *m);
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-10-31 21:33:00 +0000