DM: add new monitor module

This monitor module is to initialize socket intance, register
handlers to handle command from socket message, close socket,
free socket instance:
init_cmd_monitor: initialize socket intance and register handlers
to handle command.
deinit_cmd_monitor: close socket and free socket instance.

In this patch DM makefile is updated to build command monitor.

v1--v2:
	Update socket path and update log message format.
	Parse JSON format command message using libcjson lib APIs.
v2-->v3:
	Use socket path length MACRO.
	Update JSON format command message to {"command": "xxx"}.

Tracked-On: #5921

Signed-off-by: Xiangyang Wu <xiangyang.wu@intel.com>
Acked-by: Wang, Yu1 <yu1.wang@intel.com>

devicemodel/Makefile

@@ -171,6 +171,10 @@ SRCS += core/main.c
 SRCS += core/hugetlb.c
 SRCS += core/vrpmb.c
 SRCS += core/timer.c
+SRCS += core/cmd_monitor/socket.c
+SRCS += core/cmd_monitor/command.c
+SRCS += core/cmd_monitor/command_handler.c
+SRCS += core/cmd_monitor/cmd_monitor.c
 
 # arch
 SRCS += arch/x86/pm.c

devicemodel/core/cmd_monitor/cmd_monitor.c

@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2022 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <pthread.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <sys/un.h>
+#include <cjson/cJSON.h>
+#include "socket.h"
+#include "command.h"
+#include "vmmapi.h"
+#include "cmd_monitor.h"
+#include "log.h"
+#include "dm.h"
+#include "command_handler.h"
+
+struct socket_dev *sock_server; /* socket server instance */
+static char socket_path[UNIX_SOCKET_PATH_MAX];
+
+static struct command *parse_command(char *cmd_msg, int fd)
+{
+	struct command *cmd = NULL;
+	const cJSON *execute;
+	const cJSON *arguments;
+	cJSON *cmd_json;
+
+	cmd_json = cJSON_Parse(cmd_msg);
+	if (cmd_json == NULL) {
+		const char *error_ptr = cJSON_GetErrorPtr();
+		if (error_ptr != NULL) {
+			fprintf(stderr, "Error before: %s\n", error_ptr);
+        }
+        return NULL;
+	}
+	execute = cJSON_GetObjectItemCaseSensitive(cmd_json, "command");
+	if (cJSON_IsString(execute) && (execute->valuestring != NULL)) {
+		pr_info("Command name: \"%s\"\n", execute->valuestring);
+
+		cmd = find_command(execute->valuestring);
+		if (cmd != NULL) {
+			cmd->para.fd = fd;
+			arguments = cJSON_GetObjectItemCaseSensitive(cmd_json, "arguments");
+			if (cJSON_IsString(arguments) && (arguments->valuestring != NULL)) {
+				pr_info("Command arguments: \"%s\"\n", arguments->valuestring);
+				strncpy(cmd->para.option, arguments->valuestring, CMD_ARG_MAX - 1U);
+			}
+		} else {
+			pr_err("Command [%s] is not supported.\n", execute->valuestring);
+		}
+	}
+	cJSON_Delete(cmd_json);
+	return cmd;
+}
+static void monitor_cmd_dispatch(char *cmd_msg, int fd)
+{
+	struct command *cmd;
+
+	cmd = parse_command(cmd_msg, fd);
+	if (cmd != NULL) {
+		dispatch_command_handlers(cmd);
+	}
+	return;
+}
+
+int init_socket_server(void)
+{
+	int ret = 0;
+
+	if (strnlen(socket_path, UNIX_SOCKET_PATH_MAX) == 0) {
+		pr_err("Failed to initialize command monitor due to invalid socket path.\n");
+	}
+
+	sock_server = init_socket(socket_path);
+	if (sock_server == NULL)
+		return -1;
+	ret = open_socket(sock_server, monitor_cmd_dispatch);
+	if (ret < 0)
+		return ret;
+	return ret;
+}
+
+static void register_socket_message_handlers(struct vmctx *ctx)
+{
+	struct handler_args arg;
+	arg.channel_arg = sock_server;
+	arg.ctx_arg = ctx;
+	register_command_handler(user_vm_destroy_handler, &arg, DESTROY);
+	register_command_handler(user_vm_blkrescan_handler, &arg, BLKRESCAN);
+}
+
+int init_cmd_monitor(struct vmctx *ctx)
+{
+	int ret;
+	ret = init_socket_server();
+	register_socket_message_handlers(ctx);
+	return ret;
+}
+void deinit_cmd_monitor(void)
+{
+	if (sock_server != NULL) {
+		close_socket(sock_server);
+		deinit_socket(sock_server);
+	}
+}

devicemodel/include/cmd_monitor.h

@@ -0,0 +1,10 @@
+/*
+ * Copyright (C) 2022 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#ifndef _CMD_MONITOR_H_
+#define _CMD_MONITOR_H_
+
+int init_cmd_monitor(struct vmctx *ctx);
+void deinit_cmd_monitor(void);
+#endif