net: shell: Add net-sockets command

The new "net sockets" command will utilize the object core
support to track and show information about BSD sockets that
are created in the system. This command is able to show info
for all network sockets (native, offloaded etc) in the system.

Example of the output of the new command:

uart:~$ net sockets
 Creator  Name       Flags  FD   Lifetime (ms) Sent  Received

    main  af_inet46  6ST    0    3260          819   498
    main  af_inet46  4ST    1    2110          469   142
    main  af_inet46  6DU    2    2110          9941  9941
    main  af_inet46  4DU    3    2110          1375  621

4 active sockets found.

Signed-off-by: Jukka Rissanen <jukka.rissanen@nordicsemi.no>

doc/connectivity/networking/api/net_shell.rst

@@ -38,6 +38,9 @@ The following net-shell commands are implemented:
    "net ping", "Ping a network host."
    "net route", "Show IPv6 network routes. Only available if
    :kconfig:option:`CONFIG_NET_ROUTE` is set."
+   "net sockets", "Show network socket information and statistics. Only available if
+   :kconfig:option:`CONFIG_NET_SOCKETS_OBJ_CORE` and :kconfig:option:`CONFIG_OBJ_CORE`
+   are set."
    "net stats", "Show network statistics."
    "net tcp", "Connect/send data/close TCP connection. Only available if
    :kconfig:option:`CONFIG_NET_TCP` is set."

subsys/net/lib/shell/CMakeLists.txt

@@ -23,6 +23,7 @@ zephyr_library_sources(pkt.c)
 zephyr_library_sources(ppp.c)
 zephyr_library_sources(resume.c)
 zephyr_library_sources(route.c)
+zephyr_library_sources(sockets.c)
 zephyr_library_sources(stats.c)
 zephyr_library_sources(suspend.c)
 zephyr_library_sources(tcp.c)

subsys/net/lib/shell/sockets.c

@@ -0,0 +1,130 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_DECLARE(net_shell);
+
+#include "common.h"
+#include <zephyr/net/socket.h>
+
+#if defined(CONFIG_NET_SOCKETS_OBJ_CORE)
+struct socket_info {
+	int opened;
+	int closed;
+};
+
+int walk_sockets(struct k_obj_core *obj_core, void *user_data)
+{
+#if defined(CONFIG_THREAD_NAME)
+#define THREAD_NAME_LEN CONFIG_THREAD_MAX_NAME_LEN
+#else
+#define THREAD_NAME_LEN 16
+#endif
+	struct sock_obj_type_raw_stats stats = { 0 };
+	struct net_shell_user_data *data = user_data;
+	const struct shell *sh = data->sh;
+	struct socket_info *count = data->user_data;
+	char thread_name[THREAD_NAME_LEN + 1];
+	char fd[5] = { 0 };
+	struct sock_obj *obj;
+	int lifetime;
+	int ret;
+
+	obj = CONTAINER_OF(obj_core, struct sock_obj, obj_core);
+
+	if (k_thread_name_copy(obj->creator, thread_name,
+			       sizeof(thread_name) - 1) < 0) {
+		snprintk(thread_name, sizeof(thread_name) - 1, "%p",
+			 obj->creator);
+	}
+
+	thread_name[sizeof(thread_name) - 1] = '\0';
+
+	ret = k_obj_core_stats_raw(K_OBJ_CORE(obj),
+				   &stats, sizeof(stats));
+	if (ret != 0) {
+		PR_INFO("Failed to get statistics (%d)\n", ret);
+	}
+
+	if (obj->fd < 0) {
+		/* Already closed socket. The create time contains the
+		 * actual lifetime as calculated in close()
+		 */
+		lifetime = obj->create_time;
+		strncat(fd, "C", 1);
+		count->closed++;
+	} else {
+		lifetime = k_ticks_to_ms_ceil32(sys_clock_tick_get() -
+						obj->create_time);
+		snprintk(fd, sizeof(fd), "%d", obj->fd);
+		count->opened++;
+	}
+
+	PR("%16s  %-12s  %c%c%c\t%-5s%-13d   %-10" PRId64 "%-10" PRId64 "\n",
+	   thread_name, obj->reg->name,
+	   obj->socket_family == AF_INET6 ? '6' :
+	   (obj->socket_family ? '4' : ' '),
+	   obj->socket_type == SOCK_DGRAM ? 'D' :
+	   (obj->socket_type == SOCK_STREAM ? 'S' :
+	    (obj->socket_type == SOCK_RAW ? 'R' : ' ')),
+	   obj->socket_proto == IPPROTO_UDP ? 'U' :
+	   (obj->socket_proto == IPPROTO_TCP ? 'T' : ' '),
+	   fd, lifetime, stats.sent, stats.received);
+
+	return 0;
+}
+#endif /* CONFIG_NET_SOCKETS_OBJ_CORE */
+
+static int cmd_net_sockets(const struct shell *sh, size_t argc, char *argv[])
+{
+#if defined(CONFIG_NET_SOCKETS_OBJ_CORE)
+	struct net_shell_user_data user_data;
+	struct k_obj_type *obj_type;
+	struct socket_info count = { 0 };
+
+	user_data.sh = sh;
+	user_data.user_data = &count;
+
+	PR("%16s  %-12s  %-5s\t%-5s%-14s  %-10s%-10s\n",
+	   "Creator", "Name", "Flags", "FD", "Lifetime (ms)", "Sent",
+	   "Received");
+	PR("\n");
+
+	obj_type = k_obj_type_find(K_OBJ_TYPE_SOCK);
+	k_obj_type_walk_unlocked(obj_type, walk_sockets, (void *)&user_data);
+
+	if (count.opened == 0 && count.closed == 0) {
+		PR("No sockets found.\n");
+	} else {
+		if (count.opened > 0) {
+			PR("\n%d active socket%s found.\n", count.opened,
+			   count.opened == 1 ? "" : "s");
+		}
+
+		if (count.closed > 0) {
+			if (count.opened == 0) {
+				PR("\n");
+			}
+
+			PR("%d closed socket%s found.\n", count.closed,
+			   count.closed == 1 ? "" : "s");
+		}
+	}
+#else
+	ARG_UNUSED(argc);
+	ARG_UNUSED(argv);
+
+	PR_INFO("Set %s to enable %s support.\n",
+		"CONFIG_OBJ_CORE and CONFIG_NET_SOCKETS_OBJ_CORE",
+		"socket information");
+#endif
+
+	return 0;
+}
+
+SHELL_SUBCMD_ADD((net), sockets, NULL,
+		 "Show network sockets.",
+		 cmd_net_sockets, 1, 0);