+ if (state != DNS_QUERY_SENT) {
+ dns_query_transaction_stop(t);
+ dns_query_finish(t->query);
+ }
+}
+
+static int on_tcp_ready(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+ DnsQueryTransaction *t = userdata;
+ int r;
+
+ assert(t);
+
+ if (revents & EPOLLOUT) {
+ struct iovec iov[2];
+ be16_t sz;
+ ssize_t ss;
+
+ sz = htobe16(t->sent->size);
+
+ iov[0].iov_base = &sz;
+ iov[0].iov_len = sizeof(sz);
+ iov[1].iov_base = DNS_PACKET_DATA(t->sent);
+ iov[1].iov_len = t->sent->size;
+
+ IOVEC_INCREMENT(iov, 2, t->tcp_written);
+
+ ss = writev(fd, iov, 2);
+ if (ss < 0) {
+ if (errno != EINTR && errno != EAGAIN) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return -errno;
+ }
+ } else
+ t->tcp_written += ss;
+
+ /* Are we done? If so, disable the event source for EPOLLOUT */
+ if (t->tcp_written >= sizeof(sz) + t->sent->size) {
+ r = sd_event_source_set_io_events(s, EPOLLIN);
+ if (r < 0) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return r;
+ }
+ }
+ }
+
+ if (revents & (EPOLLIN|EPOLLHUP|EPOLLRDHUP)) {
+
+ if (t->tcp_read < sizeof(t->tcp_read_size)) {
+ ssize_t ss;
+
+ ss = read(fd, (uint8_t*) &t->tcp_read_size + t->tcp_read, sizeof(t->tcp_read_size) - t->tcp_read);
+ if (ss < 0) {
+ if (errno != EINTR && errno != EAGAIN) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return -errno;
+ }
+ } else if (ss == 0) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return -EIO;
+ } else
+ t->tcp_read += ss;
+ }
+
+ if (t->tcp_read >= sizeof(t->tcp_read_size)) {
+
+ if (be16toh(t->tcp_read_size) < DNS_PACKET_HEADER_SIZE) {
+ dns_query_transaction_set_state(t, DNS_QUERY_INVALID_REPLY);
+ return -EBADMSG;
+ }
+
+ if (t->tcp_read < sizeof(t->tcp_read_size) + be16toh(t->tcp_read_size)) {
+ ssize_t ss;
+
+ if (!t->received) {
+ r = dns_packet_new(&t->received, be16toh(t->tcp_read_size));
+ if (r < 0) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return r;
+ }
+ }
+
+ ss = read(fd,
+ (uint8_t*) DNS_PACKET_DATA(t->received) + t->tcp_read - sizeof(t->tcp_read_size),
+ sizeof(t->tcp_read_size) + be16toh(t->tcp_read_size) - t->tcp_read);
+ if (ss < 0) {
+ if (errno != EINTR && errno != EAGAIN) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return -errno;
+ }
+ } else if (ss == 0) {
+ dns_query_transaction_set_state(t, DNS_QUERY_RESOURCES);
+ return -EIO;
+ } else
+ t->tcp_read += ss;
+ }
+
+ if (t->tcp_read >= sizeof(t->tcp_read_size) + be16toh(t->tcp_read_size)) {
+ t->received->size = be16toh(t->tcp_read_size);
+ dns_query_transaction_reply(t, t->received);
+ return 0;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static int dns_query_transaction_start_tcp(DnsQueryTransaction *t) {
+ int r;
+
+ assert(t);
+
+ if (t->tcp_fd >= 0)
+ return 0;
+
+ t->tcp_written = 0;
+ t->tcp_read = 0;
+ t->received = dns_packet_unref(t->received);
+
+ t->tcp_fd = dns_scope_tcp_socket(t->scope);
+ if (t->tcp_fd < 0)
+ return t->tcp_fd;
+
+ r = sd_event_add_io(t->query->manager->event, &t->tcp_event_source, t->tcp_fd, EPOLLIN|EPOLLOUT, on_tcp_ready, t);
+ if (r < 0) {
+ t->tcp_fd = safe_close(t->tcp_fd);
+ return r;
+ }