]> git.ipfire.org Git - thirdparty/systemd.git/blobdiff - src/resolve/resolved-dns-stream.c
fix(journal-gatewayd): use relative urls (not starting with '/')
[thirdparty/systemd.git] / src / resolve / resolved-dns-stream.c
index d133efa751e43d0e9267b06a743a3d191ef0dcd3..04ba1d91bcd12841b9ea249c103e9d630a4a39ec 100644 (file)
@@ -11,7 +11,7 @@
 #define DNS_STREAM_TIMEOUT_USEC (10 * USEC_PER_SEC)
 #define DNS_STREAMS_MAX 128
 
-#define WRITE_TLS_DATA 1
+#define DNS_QUERIES_PER_STREAM 32
 
 static void dns_stream_stop(DnsStream *s) {
         assert(s);
@@ -19,6 +19,9 @@ static void dns_stream_stop(DnsStream *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) {
@@ -35,29 +38,44 @@ 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 HAVE_GNUTLS
-        if (s->tls_session && IN_SET(error, ETIMEDOUT, 0)) {
+#if ENABLE_DNS_OVER_TLS
+        if (s->encrypted) {
                 int r;
 
-                r = gnutls_bye(s->tls_session, GNUTLS_SHUT_RDWR);
-                if (r == GNUTLS_E_AGAIN && !s->tls_bye) {
-                        dns_stream_ref(s); /* keep reference for closing TLS session */
-                        s->tls_bye = true;
-                } else
+                r = dnstls_stream_shutdown(s, error);
+                if (r != -EAGAIN)
                         dns_stream_stop(s);
         } else
 #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 */
@@ -191,34 +209,24 @@ static int dns_stream_identify(DnsStream *s) {
         return 0;
 }
 
-static ssize_t dns_stream_writev(DnsStream *s, const struct iovec *iov, size_t iovcnt, int flags) {
-        ssize_t r;
+ssize_t dns_stream_writev(DnsStream *s, const struct iovec *iov, size_t iovcnt, int flags) {
+        ssize_t m;
 
         assert(s);
         assert(iov);
 
-#if HAVE_GNUTLS
-        if (s->tls_session && !(flags & WRITE_TLS_DATA)) {
+#if ENABLE_DNS_OVER_TLS
+        if (s->encrypted && !(flags & DNS_STREAM_WRITE_TLS_DATA)) {
                 ssize_t ss;
                 size_t i;
 
-                r = 0;
+                m = 0;
                 for (i = 0; i < iovcnt; i++) {
-                        ss = gnutls_record_send(s->tls_session, iov[i].iov_base, iov[i].iov_len);
-                        if (ss < 0) {
-                                switch(ss) {
-
-                                case GNUTLS_E_INTERRUPTED:
-                                        return -EINTR;
-                                case GNUTLS_E_AGAIN:
-                                        return -EAGAIN;
-                                default:
-                                        log_debug("Failed to invoke gnutls_record_send: %s", gnutls_strerror(ss));
-                                        return -EIO;
-                                }
-                        }
+                        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;
                 }
@@ -232,80 +240,47 @@ static ssize_t dns_stream_writev(DnsStream *s, const struct iovec *iov, size_t i
                         .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) {
         ssize_t ss;
 
-#if HAVE_GNUTLS
-        if (s->tls_session) {
-                ss = gnutls_record_recv(s->tls_session, buf, count);
-                if (ss < 0) {
-                        switch(ss) {
-
-                        case GNUTLS_E_INTERRUPTED:
-                                return -EINTR;
-                        case GNUTLS_E_AGAIN:
-                                return -EAGAIN;
-                        default:
-                                log_debug("Failed to invoke gnutls_record_send: %s", gnutls_strerror(ss));
-                                return -EIO;
-                        }
-                } else if (s->on_connection) {
-                        int r;
-
-                        r = s->on_connection(s);
-                        s->on_connection = NULL; /* only call once */
-                        if (r < 0)
-                                return r;
-                }
-        } else
+#if ENABLE_DNS_OVER_TLS
+        if (s->encrypted)
+                ss = dnstls_stream_read(s, buf, count);
+        else
 #endif
         {
                 ss = read(s->fd, buf, count);
                 if (ss < 0)
-                        ss = -errno;
+                        return -errno;
         }
 
         return ss;
 }
 
-#if HAVE_GNUTLS
-static ssize_t dns_stream_tls_writev(gnutls_transport_ptr_t p, const giovec_t * iov, int iovcnt) {
-        int r;
-
-        assert(p);
-
-        r = dns_stream_writev((DnsStream*) p, (struct iovec*) iov, iovcnt, WRITE_TLS_DATA);
-        if (r < 0) {
-                errno = -r;
-                return -1;
-        }
-
-        return r;
-}
-#endif
-
 static int on_stream_timeout(sd_event_source *es, usec_t usec, void *userdata) {
         DnsStream *s = userdata;
 
@@ -315,42 +290,25 @@ static int on_stream_timeout(sd_event_source *es, usec_t usec, void *userdata) {
 }
 
 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 HAVE_GNUTLS
-        if (s->tls_bye) {
-                assert(s->tls_session);
-
-                r = gnutls_bye(s->tls_session, GNUTLS_SHUT_RDWR);
-                if (r != GNUTLS_E_AGAIN) {
-                        s->tls_bye = false;
-                        dns_stream_unref(s);
-                }
-
-                return 0;
-        }
-
-        if (s->tls_handshake < 0) {
-                assert(s->tls_session);
-
-                s->tls_handshake = gnutls_handshake(s->tls_session);
-                if (s->tls_handshake >= 0) {
-                        if (s->on_connection && !(gnutls_session_get_flags(s->tls_session) & GNUTLS_SFLAGS_FALSE_START)) {
-                                r = s->on_connection(s);
-                                s->on_connection = NULL; /* only call once */
-                                if (r < 0)
-                                        return r;
-                        }
-                } else {
-                        if (gnutls_error_is_fatal(s->tls_handshake))
-                                return dns_stream_complete(s, ECONNREFUSED);
-                        else
-                                return 0;
-                }
+#if ENABLE_DNS_OVER_TLS
+        if (s->encrypted) {
+                r = dnstls_stream_on_io(s, revents);
+                if (r == DNSTLS_STREAM_CLOSED)
+                        return 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
 
@@ -368,10 +326,8 @@ static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *use
                 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);
 
@@ -379,8 +335,10 @@ static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *use
                 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) {
@@ -403,8 +361,10 @@ static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *use
                                         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)) {
@@ -449,8 +409,8 @@ static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *use
                                           (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
@@ -475,39 +435,40 @@ static int on_stream_io(sd_event_source *es, int fd, uint32_t revents, void *use
                 }
         }
 
-        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 HAVE_GNUTLS
-        if (s->tls_session)
-                gnutls_deinit(s->tls_session);
+#if ENABLE_DNS_OVER_TLS
+        if (s->encrypted)
+                dnstls_stream_free(s);
 #endif
 
         ORDERED_SET_FOREACH(p, s->write_queue, i)
@@ -522,38 +483,44 @@ DnsStream *dns_stream_unref(DnsStream *s) {
         return mfree(s);
 }
 
-DnsStream *dns_stream_ref(DnsStream *s) {
-        if (!s)
-                return NULL;
-
-        assert(s->n_ref > 0);
-        s->n_ref++;
+DEFINE_TRIVIAL_REF_UNREF_FUNC(DnsStream, dns_stream, dns_stream_free);
 
-        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;
@@ -572,39 +539,26 @@ int dns_stream_new(Manager *m, DnsStream **ret, DnsProtocol protocol, int fd, co
         (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;
 }
 
-#if HAVE_GNUTLS
-int dns_stream_connect_tls(DnsStream *s, gnutls_session_t tls_session) {
-        gnutls_transport_set_ptr2(tls_session, (gnutls_transport_ptr_t) (long) s->fd, s);
-        gnutls_transport_set_vec_push_function(tls_session, &dns_stream_tls_writev);
-
-        s->encrypted = true;
-        s->tls_session = tls_session;
-        s->tls_handshake = gnutls_handshake(tls_session);
-        if (s->tls_handshake < 0 && gnutls_error_is_fatal(s->tls_handshake))
-                return -ECONNREFUSED;
-
-        return 0;
-}
-#endif
-
 int dns_stream_write_packet(DnsStream *s, DnsPacket *p) {
         int r;
 
         assert(s);
+        assert(p);
 
         r = ordered_set_put(s->write_queue, p);
         if (r < 0)
@@ -614,3 +568,31 @@ int dns_stream_write_packet(DnsStream *s, DnsPacket *p) {
 
         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);
+}