rest: add shell/list

Add GET shell/list request to obtain the list of scripts available
in /opt/opengnsys/client/shell

Resquest payload structure: no paylaod

Response's structure:
{
    'scripts': ['script', 'script2']
}

src/rest.c

@@ -832,6 +832,102 @@ static int og_cmd_run_get(json_t *element, struct og_msg_params *params,
 	return 0;
 }
 
+#define OG_SCRIPT_PATH "/opt/opengnsys/client/shell"
+
+struct script_entry {
+    char name[FILENAME_MAX];
+    struct list_head list;
+};
+
+static void og_script_list_free(struct list_head *script_list)
+{
+	struct script_entry *script, *tmp;
+
+	list_for_each_entry_safe(script, tmp, script_list, list) {
+		list_del(&script->list);
+		free(script);
+	}
+}
+
+static int og_get_client_scripts(struct list_head *script_list)
+{
+	struct script_entry *script;
+	struct dirent *dent;
+	DIR *d;
+
+	d = opendir(OG_SCRIPT_PATH);
+	if (!d) {
+		syslog(LOG_ERR, "Cannot open directory %s (%s:%d)\n",
+		       OG_SCRIPT_PATH, __func__, __LINE__);
+		return -1;
+	}
+
+	dent = readdir(d);
+	while (dent) {
+		if (dent->d_type != DT_REG) {
+			dent = readdir(d);
+			continue;
+		}
+
+		script = calloc(1, sizeof(struct script_entry));
+		if (!script) {
+			closedir(d);
+			og_script_list_free(script_list);
+			return -1;
+		}
+
+		snprintf(script->name, FILENAME_MAX, "%s", dent->d_name);
+		list_add_tail(&script->list, script_list);
+
+		dent = readdir(d);
+	}
+	closedir(d);
+
+	return 0;
+}
+
+static int og_cmd_shell_list(char *buffer_reply)
+{
+	struct og_buffer og_buffer = {
+		.data = buffer_reply
+	};
+	struct script_entry *entry;
+	json_t *root, *script_arr;
+	LIST_HEAD(script_list);
+
+	if (og_get_client_scripts(&script_list) < 0)
+		return -1;
+
+	root = json_object();
+	if (!root) {
+		og_script_list_free(&script_list);
+		return -1;
+	}
+
+	script_arr = json_array();
+	if (!script_arr) {
+		og_script_list_free(&script_list);
+		json_decref(root);
+		return -1;
+	}
+
+	list_for_each_entry(entry, &script_list, list)
+		json_array_append_new(script_arr, json_string(entry->name));
+
+	json_object_set_new(root, "scripts", script_arr);
+
+	if (json_dump_callback(root, og_json_dump_clients, &og_buffer, 0)) {
+		og_script_list_free(&script_list);
+		json_decref(root);
+		return -1;
+	}
+
+	og_script_list_free(&script_list);
+	json_decref(root);
+
+	return 0;
+}
+
 static int og_cmd_session(json_t *element, struct og_msg_params *params)
 {
 	json_t *clients, *value;
@@ -7640,6 +7736,7 @@ struct {
 	[OG_URI_WOL]		= { "wol", },
 	[OG_URI_SHELL_RUN]	= { "shell/run", },
 	[OG_URI_SHELL_OUTPUT]	= { "shell/output", },
+	[OG_URI_SHELL_LIST]	= { "shell/list", },
 	[OG_URI_SESSION]	= { "session", },
 	[OG_URI_SCOPES]		= { "scopes", },
 	[OG_URI_POWEROFF]	= { "poweroff", },
@@ -8009,6 +8106,13 @@ int og_client_state_process_payload_rest(struct og_client *cli)
 		}
 
 		err = og_cmd_run_get(root, &params, buf_reply);
+	} else if (!strncmp(cmd, "shell/list", strlen("shell/list"))) {
+		if (method != OG_METHOD_GET) {
+			err = og_client_method_not_found(cli);
+			goto err_process_rest_payload;
+		}
+
+		err = og_cmd_shell_list(buf_reply);
 	} else if (!strncmp(cmd, "session", strlen("session"))) {
 		if (method != OG_METHOD_POST && method != OG_METHOD_GET) {
 			err = og_client_method_not_found(cli);

src/rest.h

@@ -105,6 +105,7 @@ enum og_rest_uri {
 	OG_URI_WOL,
 	OG_URI_SHELL_RUN,
 	OG_URI_SHELL_OUTPUT,
+	OG_URI_SHELL_LIST,
 	OG_URI_SESSION,
 	OG_URI_SCOPES,
 	OG_URI_POWEROFF,