return;
}
+ /* Note that we always immediately reply to all LLMNR
+ * requests, and do not wait any time, since we
+ * verified uniqueness for all records. Also see RFC
+ * 4795, Section 2.7 */
+
r = manager_send(s->manager, fd, p->ifindex, p->family, &p->sender, p->sender_port, reply);
}
}
}
+ if (t->scope->protocol == DNS_PROTOCOL_LLMNR && !t->initial_jitter) {
+ usec_t jitter;
+
+ /* RFC 4795 Section 2.7 suggests all queries should be
+ * delayed by a random time from 0 to JITTER_INTERVAL. */
+
+ t->initial_jitter = true;
+
+ random_bytes(&jitter, sizeof(jitter));
+ jitter %= LLMNR_JITTER_INTERVAL_USEC;
+
+ r = sd_event_add_time(
+ t->scope->manager->event,
+ &t->timeout_event_source,
+ clock_boottime_or_monotonic(),
+ now(clock_boottime_or_monotonic()) + jitter, LLMNR_JITTER_INTERVAL_USEC,
+ on_transaction_timeout, t);
+ if (r < 0)
+ return r;
+
+ t->n_attempts = 0;
+ t->state = DNS_TRANSACTION_PENDING;
+
+ log_debug("Delaying LLMNR transaction for " USEC_FMT "us.", jitter);
+ return 0;
+ }
+
log_debug("Cache miss!");
/* Otherwise, we need to ask the network */
DnsTransactionState state;
uint16_t id;
+ bool initial_jitter;
+
DnsPacket *sent, *received;
DnsAnswer *cached;
int cached_rcode;
#define LLMNR_TRANSACTION_TIMEOUT_USEC (1 * USEC_PER_SEC)
/* LLMNR Jitter interval, see RFC 4795 Section 7 */
-#define LLMNR_TRANSACTION_JITTER_INTERVAL_USEC (100 * USEC_PER_MSEC)
+#define LLMNR_JITTER_INTERVAL_USEC (100 * USEC_PER_MSEC)
/* Maximum attempts to send DNS requests, across all DNS servers */
#define DNS_TRANSACTION_ATTEMPTS_MAX 8