adopt: allow binding to parent at same time

- if protocol set, allocate own user_space

   If the child wsi wants the parent wsi user_space, it can use

       lws_wsi_user(lws_get_parent(child_wsi))

 - raw file close processing handles parent-child relationship

lib/libwebsockets.c

@@ -142,11 +142,34 @@ lws_set_timeout(struct lws *wsi, enum pending_timeout reason, int secs)
 		lws_remove_from_timeout_list(wsi);
 }
 
+static void
+lws_remove_child_from_any_parent(struct lws *wsi)
+{
+	struct lws **pwsi;
+
+	if (wsi->parent) {
+		/* detach ourselves from parent's child list */
+		pwsi = &wsi->parent->child_list;
+		while (*pwsi) {
+			if (*pwsi == wsi) {
+				//lwsl_notice("%s: detach %p from parent %p\n",
+				//		__func__, wsi, wsi->parent);
+				*pwsi = wsi->sibling_list;
+				break;
+			}
+			pwsi = &(*pwsi)->sibling_list;
+		}
+		if (*pwsi)
+			lwsl_err("%s: failed to detach from parent\n",
+					__func__);
+	}
+}
+
 void
 lws_close_free_wsi(struct lws *wsi, enum lws_close_status reason)
 {
 	struct lws_context_per_thread *pt;
-	struct lws **pwsi, *wsi1, *wsi2;
+	struct lws *wsi1, *wsi2;
 	struct lws_context *context;
 	struct lws_tokens eff_buf;
 	int n, m, ret;
@@ -154,15 +177,6 @@ lws_close_free_wsi(struct lws *wsi, enum lws_close_status reason)
 	if (!wsi)
 		return;
 
-	if (wsi->mode == LWSCM_RAW_FILEDESC) {
-		remove_wsi_socket_from_fds(wsi);
-		wsi->protocol->callback(wsi,
-			LWS_CALLBACK_RAW_CLOSE_FILE, wsi->user_space, NULL, 0);
-		lws_free_wsi(wsi);
-
-		return;
-	}
-
 	lws_access_log(wsi);
 #if defined(LWS_WITH_ESP8266)
 	if (wsi->premature_rx)
@@ -200,6 +214,17 @@ lws_close_free_wsi(struct lws *wsi, enum lws_close_status reason)
 		wsi->child_list = NULL;
 	}
 
+	if (wsi->mode == LWSCM_RAW_FILEDESC) {
+			lws_remove_child_from_any_parent(wsi);
+			remove_wsi_socket_from_fds(wsi);
+			wsi->protocol->callback(wsi,
+						LWS_CALLBACK_RAW_CLOSE_FILE,
+						wsi->user_space, NULL, 0);
+			lws_free_wsi(wsi);
+
+			return;
+	}
+
 #ifdef LWS_WITH_CGI
 	if (wsi->mode == LWSCM_CGI) {
 		/* we are not a network connection, but a handler for CGI io */
@@ -400,22 +425,8 @@ lws_close_free_wsi(struct lws *wsi, enum lws_close_status reason)
 
 just_kill_connection:
 
-	if (wsi->parent) {
-		/* detach ourselves from parent's child list */
-		pwsi = &wsi->parent->child_list;
-		while (*pwsi) {
-			if (*pwsi == wsi) {
-				//lwsl_notice("%s: detach %p from parent %p\n",
-				//		__func__, wsi, wsi->parent);
-				*pwsi = wsi->sibling_list;
-				break;
-			}
-			pwsi = &(*pwsi)->sibling_list;
-		}
-		if (*pwsi)
-			lwsl_err("%s: failed to detach from parent\n",
-					__func__);
-	}
+	lws_remove_child_from_any_parent(wsi);
+
 #if 0
 	/* manage the vhost same protocol list entry */
 

lib/libwebsockets.h

@@ -3725,9 +3725,10 @@ LWS_VISIBLE LWS_EXTERN struct lws *
 lws_adopt_socket_vhost(struct lws_vhost *vh, lws_sockfd_type accept_fd);
 
 typedef enum {
-	LWS_ADOPT_HTTP = 1,		/* absent implies RAW */
-	LWS_ADOPT_SOCKET = 2,		/* absent implies file descriptor */
-	LWS_ADOPT_ALLOW_SSL = 4		/* if set requires LWS_ADOPT_SOCKET */
+	LWS_ADOPT_RAW_FILE_DESC = 0,	/* convenience constant */
+	LWS_ADOPT_HTTP = 1,		/* flag: absent implies RAW */
+	LWS_ADOPT_SOCKET = 2,		/* flag: absent implies file descr */
+	LWS_ADOPT_ALLOW_SSL = 4		/* flag: if set requires LWS_ADOPT_SOCKET */
 } lws_adoption_type;
 
 typedef union {
@@ -3743,17 +3744,21 @@ typedef union {
 * \param type: OR-ed combinations of lws_adoption_type flags
 * \param fd: union with either .sockfd or .filefd set
 * \param vh_prot_name: NULL or vh protocol name to bind raw connection to
+* \param parent: NULL or struct lws to attach new_wsi to as a child
 *
 * Either returns new wsi bound to accept_fd, or closes accept_fd and
 * returns NULL, having cleaned up any new wsi pieces.
 *
 * If LWS_ADOPT_SOCKET is set, LWS adopts the socket in http serving mode, it's
 * ready to accept an upgrade to ws or just serve http.
+*
+* parent may be NULL, if given it should be an existing wsi that will become the
+* parent of the new wsi created by this call.
 */
 LWS_VISIBLE struct lws *
 lws_adopt_descriptor_vhost(struct lws_vhost *vh, lws_adoption_type type,
-			   lws_sock_file_fd_type fd, const char *vh_prot_name);
-
+			   lws_sock_file_fd_type fd, const char *vh_prot_name,
+			   struct lws *parent);
 
 /**
  * lws_adopt_socket_readbuf() - adopt foreign socket and first rx as if listen socket accepted it

lib/server.c

@@ -1690,7 +1690,8 @@ lws_http_transaction_completed(struct lws *wsi)
 
 LWS_VISIBLE struct lws *
 lws_adopt_descriptor_vhost(struct lws_vhost *vh, lws_adoption_type type,
-			   lws_sock_file_fd_type fd, const char *vh_prot_name)
+			   lws_sock_file_fd_type fd, const char *vh_prot_name,
+			   struct lws *parent)
 {
 	struct lws_context *context = vh->context;
 	struct lws *new_wsi = lws_create_new_server_wsi(vh);
@@ -1702,27 +1703,32 @@ lws_adopt_descriptor_vhost(struct lws_vhost *vh, lws_adoption_type type,
 		return NULL;
 	}
 
-	new_wsi->desc = fd;
-	new_wsi->protocol = &context->vhost_list->
-			protocols[vh->default_protocol_index];
+	if (parent) {
+		new_wsi->parent = parent;
+		new_wsi->sibling_list = parent->child_list;
+		parent->child_list = new_wsi;
+	}
 
-	if (!(type & LWS_ADOPT_SOCKET)) {
+	new_wsi->desc = fd;
+
+	if (vh_prot_name) {
 		new_wsi->protocol = lws_vhost_name_to_protocol(new_wsi->vhost,
-				vh_prot_name);
+							       vh_prot_name);
 		if (!new_wsi->protocol) {
 			lwsl_err("Protocol %s not enabled on vhost %s\n",
 				 vh_prot_name, new_wsi->vhost->name);
-			lws_free(new_wsi);
-
-			return NULL;
+			goto bail;
 		}
-	}
-	if (type & LWS_ADOPT_SOCKET) {
+		if (lws_ensure_user_space(new_wsi))
+			goto bail;
+	} else
+		new_wsi->protocol = &context->vhost_list->
+					protocols[vh->default_protocol_index];
 
+	if (type & LWS_ADOPT_SOCKET) { /* socket desc */
 		lwsl_debug("%s: new wsi %p, sockfd %d\n", __func__, new_wsi,
 			   (int)(size_t)fd.sockfd);
 
-
 		/* the transport is accepted... give him time to negotiate */
 		lws_set_timeout(new_wsi, PENDING_TIMEOUT_ESTABLISH_WITH_SERVER,
 				context->timeout_secs);
@@ -1732,7 +1738,7 @@ lws_adopt_descriptor_vhost(struct lws_vhost *vh, lws_adoption_type type,
 		esp8266_tcp_stream_accept(accept_fd, new_wsi);
 #endif
 #endif
-	} else  //* file desc */
+	} else /* file desc */
 		lwsl_debug("%s: new wsi %p, filefd %d\n", __func__, new_wsi,
 			   (int)(size_t)fd.filefd);
 
@@ -1756,8 +1762,7 @@ lws_adopt_descriptor_vhost(struct lws_vhost *vh, lws_adoption_type type,
 			lws_set_timeout(new_wsi, NO_PENDING_TIMEOUT, 0);
 			compatible_close(new_wsi->desc.sockfd);
 		}
-		lws_free(new_wsi);
-		return NULL;
+		goto bail;
 	}
 
 	if (!LWS_SSL_ENABLED(new_wsi->vhost) || !(type & LWS_ADOPT_ALLOW_SSL) ||
@@ -1804,6 +1809,15 @@ fail:
 		lws_close_free_wsi(new_wsi, LWS_CLOSE_STATUS_NOSTATUS);
 
 	return NULL;
+
+bail:
+	if (parent)
+		parent->child_list = new_wsi->sibling_list;
+	if (new_wsi->user_space)
+		lws_free(new_wsi->user_space);
+	lws_free(new_wsi);
+
+	return NULL;
 }
 
 LWS_VISIBLE struct lws *
@@ -1813,7 +1827,7 @@ lws_adopt_socket_vhost(struct lws_vhost *vh, lws_sockfd_type accept_fd)
 
 	fd.sockfd = accept_fd;
 	return lws_adopt_descriptor_vhost(vh, LWS_ADOPT_SOCKET |
-			LWS_ADOPT_HTTP | LWS_ADOPT_ALLOW_SSL, fd, NULL);
+			LWS_ADOPT_HTTP | LWS_ADOPT_ALLOW_SSL, fd, NULL, NULL);
 }
 
 LWS_VISIBLE struct lws *

plugins/protocol_lws_raw_test.c

@@ -101,7 +101,7 @@ callback_raw_test(struct lws *wsi, enum lws_callback_reasons reason,
 		}
 		lwsl_notice("FIFO %s created\n", vhd->fifo_path);
 		u.filefd = vhd->fifo;
-		if (!lws_adopt_descriptor_vhost(vhd->vhost, 0, u, "protocol-lws-raw-test")) {
+		if (!lws_adopt_descriptor_vhost(vhd->vhost, 0, u, "protocol-lws-raw-test", NULL)) {
 			lwsl_err("Failed to adopt fifo descriptor\n");
 			close(vhd->fifo);
 			unlink(vhd->fifo_path);
@@ -167,7 +167,7 @@ callback_raw_test(struct lws *wsi, enum lws_callback_reasons reason,
 			}
 			lwsl_notice("FIFO %s reopened\n", vhd->fifo_path);
 			u.filefd = vhd->fifo;
-			if (!lws_adopt_descriptor_vhost(vhd->vhost, 0, u, "protocol-lws-raw-test")) {
+			if (!lws_adopt_descriptor_vhost(vhd->vhost, 0, u, "protocol-lws-raw-test", NULL)) {
 				lwsl_err("Failed to adopt fifo descriptor\n");
 				close(vhd->fifo);
 				return 1;