+ continue;
+ }
+ }
+
+ if(sent != (ssize_t)todo) {
+ /* We should never get a partial send at this point */
+ assert(sent <= 0);
+
+ /* Sending failed, abort all outstanding AIO buffers and send a poll callback. */
+ if(!aio_abort(mesh, channel, &channel->aio_send)) {
+ return;
+ }
+
+ len = 0;
+ break;
+ }
+
+ aio->done += sent;
+ len -= sent;
+
+ /* If we didn't finish this buffer, exit early. */
+ if(aio->done < aio->len) {
+ return;
+ }
+
+ /* Signal completion of this buffer, and go to the next one. */
+ if(!aio_finish_one(mesh, channel, &channel->aio_send)) {
+ return;
+ }
+
+ if(!len) {
+ return;
+ }
+ }
+
+ if(channel->poll_cb) {
+ channel->poll_cb(mesh, channel, len);
+ } else {
+ utcp_set_poll_cb(connection, NULL);
+ }
+}
+
+void meshlink_set_channel_poll_cb(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_channel_poll_cb_t cb) {
+ if(!mesh || !channel) {
+ meshlink_errno = MESHLINK_EINVAL;
+ return;
+ }
+
+ if(pthread_mutex_lock(&mesh->mutex) != 0) {
+ abort();
+ }
+
+ channel->poll_cb = cb;
+ utcp_set_poll_cb(channel->c, (cb || channel->aio_send) ? channel_poll : NULL);
+ pthread_mutex_unlock(&mesh->mutex);
+}
+
+void meshlink_set_channel_listen_cb(meshlink_handle_t *mesh, meshlink_channel_listen_cb_t cb) {
+ if(!mesh) {
+ meshlink_errno = MESHLINK_EINVAL;
+ return;
+ }
+
+ if(pthread_mutex_lock(&mesh->mutex) != 0) {
+ abort();
+ }
+
+ mesh->channel_listen_cb = cb;
+
+ pthread_mutex_unlock(&mesh->mutex);
+}
+
+void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_accept_cb_t cb) {
+ if(!mesh) {
+ meshlink_errno = MESHLINK_EINVAL;
+ return;
+ }
+
+ if(pthread_mutex_lock(&mesh->mutex) != 0) {
+ abort();
+ }
+
+ mesh->channel_accept_cb = cb;
+ mesh->receive_cb = channel_receive;
+
+ for splay_each(node_t, n, mesh->nodes) {
+ if(!n->utcp && n != mesh->self) {
+ n->utcp = utcp_init(channel_accept, channel_pre_accept, channel_send, n);
+ utcp_set_mtu(n->utcp, n->mtu - sizeof(meshlink_packethdr_t));
+ utcp_set_retransmit_cb(n->utcp, channel_retransmit);
+ }
+ }
+
+ pthread_mutex_unlock(&mesh->mutex);
+}
+
+void meshlink_set_channel_sndbuf(meshlink_handle_t *mesh, meshlink_channel_t *channel, size_t size) {
+ (void)mesh;
+
+ if(!channel) {
+ meshlink_errno = MESHLINK_EINVAL;
+ return;
+ }
+
+ if(pthread_mutex_lock(&mesh->mutex) != 0) {
+ abort();
+ }
+
+ utcp_set_sndbuf(channel->c, size);
+ pthread_mutex_unlock(&mesh->mutex);
+}
+
+void meshlink_set_channel_rcvbuf(meshlink_handle_t *mesh, meshlink_channel_t *channel, size_t size) {
+ (void)mesh;
+
+ if(!channel) {
+ meshlink_errno = MESHLINK_EINVAL;
+ return;
+ }
+
+ if(pthread_mutex_lock(&mesh->mutex) != 0) {
+ abort();
+ }
+
+ utcp_set_rcvbuf(channel->c, size);
+ pthread_mutex_unlock(&mesh->mutex);
+}
+
+meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_node_t *node, uint16_t port, meshlink_channel_receive_cb_t cb, const void *data, size_t len, uint32_t flags) {
+ if(data && len) {
+ abort(); // TODO: handle non-NULL data
+ }
+
+ if(!mesh || !node) {
+ meshlink_errno = MESHLINK_EINVAL;
+ return NULL;
+ }
+
+ if(pthread_mutex_lock(&mesh->mutex) != 0) {
+ abort();
+ }
+
+ node_t *n = (node_t *)node;
+
+ if(!n->utcp) {
+ n->utcp = utcp_init(channel_accept, channel_pre_accept, channel_send, n);
+ utcp_set_mtu(n->utcp, n->mtu - sizeof(meshlink_packethdr_t));
+ utcp_set_retransmit_cb(n->utcp, channel_retransmit);
+ mesh->receive_cb = channel_receive;
+
+ if(!n->utcp) {
+ meshlink_errno = errno == ENOMEM ? MESHLINK_ENOMEM : MESHLINK_EINTERNAL;
+ pthread_mutex_unlock(&mesh->mutex);
+ return NULL;