#define DNS_STREAM_TIMEOUT_USEC (10 * USEC_PER_SEC)
#define DNS_STREAMS_MAX 128
+#define DNS_QUERIES_PER_STREAM 32
+
static void dns_stream_stop(DnsStream *s) {
assert(s);
s->io_event_source = sd_event_source_unref(s->io_event_source);
s->timeout_event_source = sd_event_source_unref(s->timeout_event_source);
s->fd = safe_close(s->fd);
+
+ /* Disconnect us from the server object if we are now not usable anymore */
+ dns_stream_detach(s);
}
static int dns_stream_update_io(DnsStream *s) {
s->n_written = 0;
f |= EPOLLOUT;
}
- if (!s->read_packet || s->n_read < sizeof(s->read_size) + s->read_packet->size)
+
+ /* Let's read a packet if we haven't queued any yet. Except if we already hit a limit of parallel
+ * queries for this connection. */
+ if ((!s->read_packet || s->n_read < sizeof(s->read_size) + s->read_packet->size) &&
+ set_size(s->queries) < DNS_QUERIES_PER_STREAM)
f |= EPOLLIN;
+#if ENABLE_DNS_OVER_TLS
+ /* For handshake and clean closing purposes, TLS can override requested events */
+ if (s->dnstls_events != 0)
+ f = s->dnstls_events;
+#endif
+
return sd_event_source_set_io_events(s->io_event_source, f);
}
static int dns_stream_complete(DnsStream *s, int error) {
+ _cleanup_(dns_stream_unrefp) _unused_ DnsStream *ref = dns_stream_ref(s); /* Protect stream while we process it */
+
assert(s);
+ assert(error >= 0);
+
+ /* Error is > 0 when the connection failed for some reason in the network stack. It's == 0 if we sent
+ * and received exactly one packet each (in the LLMNR client case). */
#if ENABLE_DNS_OVER_TLS
if (s->encrypted) {
#endif
dns_stream_stop(s);
+ dns_stream_detach(s);
+
if (s->complete)
s->complete(s, error);
else /* the default action if no completion function is set is to close the stream */
}
ssize_t dns_stream_writev(DnsStream *s, const struct iovec *iov, size_t iovcnt, int flags) {
- ssize_t r;
+ ssize_t m;
assert(s);
assert(iov);
ssize_t ss;
size_t i;
- r = 0;
+ m = 0;
for (i = 0; i < iovcnt; i++) {
ss = dnstls_stream_write(s, iov[i].iov_base, iov[i].iov_len);
if (ss < 0)
return ss;
- r += ss;
+ m += ss;
if (ss != (ssize_t) iov[i].iov_len)
continue;
}
.msg_namelen = s->tfo_salen
};
- r = sendmsg(s->fd, &hdr, MSG_FASTOPEN);
- if (r < 0) {
+ m = sendmsg(s->fd, &hdr, MSG_FASTOPEN);
+ if (m < 0) {
if (errno == EOPNOTSUPP) {
s->tfo_salen = 0;
- r = connect(s->fd, &s->tfo_address.sa, s->tfo_salen);
- if (r < 0)
+ if (connect(s->fd, &s->tfo_address.sa, s->tfo_salen) < 0)
return -errno;
- r = -EAGAIN;
- } else if (errno == EINPROGRESS)
- r = -EAGAIN;
+ return -EAGAIN;
+ }
+ if (errno == EINPROGRESS)
+ return -EAGAIN;
+
+ return -errno;
} else
s->tfo_salen = 0; /* connection is made */
} else {
- r = writev(s->fd, iov, iovcnt);
- if (r < 0)
- r = -errno;
+ m = writev(s->fd, iov, iovcnt);
+ if (m < 0)
+ return -errno;
}
- return r;
+ return m;
}
static ssize_t dns_stream_read(DnsStream *s, void *buf, size_t count) {
{
ss = read(s->fd, buf, count);
if (ss < 0)
- ss = -errno;
+ return -errno;
}
return ss;
}
static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
- DnsStream *s = userdata;
+ _cleanup_(dns_stream_unrefp) DnsStream *s = dns_stream_ref(userdata); /* Protect stream while we process it */
+ bool progressed = false;
int r;
assert(s);
#if ENABLE_DNS_OVER_TLS
if (s->encrypted) {
- r = dnstls_stream_on_io(s);
-
- if (r == DNSTLS_STREAM_CLOSED || r == -EAGAIN)
+ r = dnstls_stream_on_io(s, revents);
+ if (r == DNSTLS_STREAM_CLOSED)
return 0;
- else if (r < 0)
+ if (r == -EAGAIN)
+ return dns_stream_update_io(s);
+ if (r < 0)
return dns_stream_complete(s, -r);
+
+ r = dns_stream_update_io(s);
+ if (r < 0)
+ return r;
}
#endif
struct iovec iov[2];
ssize_t ss;
- iov[0].iov_base = &s->write_size;
- iov[0].iov_len = sizeof(s->write_size);
- iov[1].iov_base = DNS_PACKET_DATA(s->write_packet);
- iov[1].iov_len = s->write_packet->size;
+ iov[0] = IOVEC_MAKE(&s->write_size, sizeof(s->write_size));
+ iov[1] = IOVEC_MAKE(DNS_PACKET_DATA(s->write_packet), s->write_packet->size);
IOVEC_INCREMENT(iov, 2, s->n_written);
if (ss < 0) {
if (!IN_SET(-ss, EINTR, EAGAIN))
return dns_stream_complete(s, -ss);
- } else
+ } else {
+ progressed = true;
s->n_written += ss;
+ }
/* Are we done? If so, disable the event source for EPOLLOUT */
if (s->n_written >= sizeof(s->write_size) + s->write_packet->size) {
return dns_stream_complete(s, -ss);
} else if (ss == 0)
return dns_stream_complete(s, ECONNRESET);
- else
+ else {
+ progressed = true;
s->n_read += ss;
+ }
}
if (s->n_read >= sizeof(s->read_size)) {
(uint8_t*) DNS_PACKET_DATA(s->read_packet) + s->n_read - sizeof(s->read_size),
sizeof(s->read_size) + be16toh(s->read_size) - s->n_read);
if (ss < 0) {
- if (!IN_SET(errno, EINTR, EAGAIN))
- return dns_stream_complete(s, errno);
+ if (!IN_SET(-ss, EINTR, EAGAIN))
+ return dns_stream_complete(s, -ss);
} else if (ss == 0)
return dns_stream_complete(s, ECONNRESET);
else
}
}
- if ((s->write_packet && s->n_written >= sizeof(s->write_size) + s->write_packet->size) &&
+ /* Call "complete" callback if finished reading and writing one packet, and there's nothing else left
+ * to write. */
+ if (s->type == DNS_STREAM_LLMNR_SEND &&
+ (s->write_packet && s->n_written >= sizeof(s->write_size) + s->write_packet->size) &&
+ ordered_set_isempty(s->write_queue) &&
(s->read_packet && s->n_read >= sizeof(s->read_size) + s->read_packet->size))
return dns_stream_complete(s, 0);
+ /* If we did something, let's restart the timeout event source */
+ if (progressed && s->timeout_event_source) {
+ r = sd_event_source_set_time(s->timeout_event_source, now(clock_boottime_or_monotonic()) + DNS_STREAM_TIMEOUT_USEC);
+ if (r < 0)
+ log_warning_errno(errno, "Couldn't restart TCP connection timeout, ignoring: %m");
+ }
+
return 0;
}
-DnsStream *dns_stream_unref(DnsStream *s) {
+static DnsStream *dns_stream_free(DnsStream *s) {
DnsPacket *p;
Iterator i;
- if (!s)
- return NULL;
-
- assert(s->n_ref > 0);
- s->n_ref--;
-
- if (s->n_ref > 0)
- return NULL;
+ assert(s);
dns_stream_stop(s);
- if (s->server && s->server->stream == s)
- s->server->stream = NULL;
-
if (s->manager) {
LIST_REMOVE(streams, s->manager->dns_streams, s);
- s->manager->n_dns_streams--;
+ s->manager->n_dns_streams[s->type]--;
}
#if ENABLE_DNS_OVER_TLS
return mfree(s);
}
-DnsStream *dns_stream_ref(DnsStream *s) {
- if (!s)
- return NULL;
+DEFINE_TRIVIAL_REF_UNREF_FUNC(DnsStream, dns_stream, dns_stream_free);
- assert(s->n_ref > 0);
- s->n_ref++;
-
- return s;
-}
+int dns_stream_new(
+ Manager *m,
+ DnsStream **ret,
+ DnsStreamType type,
+ DnsProtocol protocol,
+ int fd,
+ const union sockaddr_union *tfo_address) {
-int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd, const union sockaddr_union *tfo_address) {
_cleanup_(dns_stream_unrefp) DnsStream *s = NULL;
int r;
assert(m);
+ assert(ret);
+ assert(type >= 0);
+ assert(type < _DNS_STREAM_TYPE_MAX);
+ assert(protocol >= 0);
+ assert(protocol < _DNS_PROTOCOL_MAX);
assert(fd >= 0);
- if (m->n_dns_streams > DNS_STREAMS_MAX)
+ if (m->n_dns_streams[type] > DNS_STREAMS_MAX)
return -EBUSY;
- s = new0(DnsStream, 1);
+ s = new(DnsStream, 1);
if (!s)
return -ENOMEM;
+ *s = (DnsStream) {
+ .n_ref = 1,
+ .fd = -1,
+ .protocol = protocol,
+ };
+
r = ordered_set_ensure_allocated(&s->write_queue, &dns_packet_hash_ops);
if (r < 0)
return r;
- s->n_ref = 1;
- s->fd = -1;
- s->protocol = protocol;
-
r = sd_event_add_io(m->event, &s->io_event_source, fd, EPOLLIN, on_stream_io, s);
if (r < 0)
return r;
(void) sd_event_source_set_description(s->timeout_event_source, "dns-stream-timeout");
LIST_PREPEND(streams, m->dns_streams, s);
+ m->n_dns_streams[type]++;
s->manager = m;
+
s->fd = fd;
+
if (tfo_address) {
s->tfo_address = *tfo_address;
s->tfo_salen = tfo_address->sa.sa_family == AF_INET6 ? sizeof(tfo_address->in6) : sizeof(tfo_address->in);
}
- m->n_dns_streams++;
-
*ret = TAKE_PTR(s);
return 0;
int r;
assert(s);
+ assert(p);
r = ordered_set_put(s->write_queue, p);
if (r < 0)
return dns_stream_update_io(s);
}
+
+DnsPacket *dns_stream_take_read_packet(DnsStream *s) {
+ assert(s);
+
+ if (!s->read_packet)
+ return NULL;
+
+ if (s->n_read < sizeof(s->read_size))
+ return NULL;
+
+ if (s->n_read < sizeof(s->read_size) + be16toh(s->read_size))
+ return NULL;
+
+ s->n_read = 0;
+ return TAKE_PTR(s->read_packet);
+}
+
+void dns_stream_detach(DnsStream *s) {
+ assert(s);
+
+ if (!s->server)
+ return;
+
+ if (s->server->stream != s)
+ return;
+
+ dns_server_unref_stream(s->server);
+}
projects / thirdparty / systemd.git / blobdiff