tools: lxc-attach: add default log priority & cleanups

src/lxc/tools/lxc_attach.c

@@ -45,6 +45,21 @@
 
 lxc_log_define(lxc_attach, lxc);
 
+static int my_parser(struct lxc_arguments *args, int c, char *arg);
+static int add_to_simple_array(char ***array, ssize_t *capacity, char *value);
+static bool stdfd_is_pty(void);
+static int lxc_attach_create_log_file(const char *log_file);
+
+static int elevated_privileges;
+static signed long new_personality = -1;
+static int namespace_flags = -1;
+static int remount_sys_proc;
+static lxc_attach_env_policy_t env_policy = LXC_ATTACH_KEEP_ENV;
+static char **extra_env;
+static ssize_t extra_env_size;
+static char **extra_keep;
+static ssize_t extra_keep_size;
+
 static const struct option my_longopts[] = {
 	{"elevated-privileges", optional_argument, 0, 'e'},
 	{"arch", required_argument, 0, 'a'},
@@ -60,43 +75,60 @@ static const struct option my_longopts[] = {
 	LXC_COMMON_OPTIONS
 };
 
-static int elevated_privileges = 0;
-static signed long new_personality = -1;
-static int namespace_flags = -1;
-static int remount_sys_proc = 0;
-static lxc_attach_env_policy_t env_policy = LXC_ATTACH_KEEP_ENV;
-static char **extra_env = NULL;
-static ssize_t extra_env_size = 0;
-static char **extra_keep = NULL;
-static ssize_t extra_keep_size = 0;
-
-static int add_to_simple_array(char ***array, ssize_t *capacity, char *value)
-{
-	ssize_t count = 0;
-
-	if (!array)
-		return -1;
-
-	if (*array)
-		for (; (*array)[count]; count++);
-
-	/* we have to reallocate */
-	if (count >= *capacity - 1) {
-		ssize_t new_capacity = ((count + 1) / 32 + 1) * 32;
-		char **new_array = realloc((void*)*array, sizeof(char *) * new_capacity);
-		if (!new_array)
-			return -1;
-		memset(&new_array[count], 0, sizeof(char*)*(new_capacity - count));
-		*array = new_array;
-		*capacity = new_capacity;
-	}
-
-	if (!(*array))
-		return -1;
-
-	(*array)[count] = value;
-	return 0;
-}
+static struct lxc_arguments my_args = {
+	.progname     = "lxc-attach",
+	.help         = "\
+--name=NAME [-- COMMAND]\n\
+\n\
+Execute the specified COMMAND - enter the container NAME\n\
+\n\
+Options :\n\
+  -n, --name=NAME   NAME of the container\n\
+  -e, --elevated-privileges=PRIVILEGES\n\
+                    Use elevated privileges instead of those of the\n\
+                    container. If you don't specify privileges to be\n\
+                    elevated as OR'd list: CAP, CGROUP and LSM (capabilities,\n\
+                    cgroup and restrictions, respectively) then all of them\n\
+                    will be elevated.\n\
+                    WARNING: This may leak privileges into the container.\n\
+                    Use with care.\n\
+  -a, --arch=ARCH   Use ARCH for program instead of container's own\n\
+                    architecture.\n\
+  -s, --namespaces=FLAGS\n\
+                    Don't attach to all the namespaces of the container\n\
+                    but just to the following OR'd list of flags:\n\
+                    MOUNT, PID, UTSNAME, IPC, USER or NETWORK.\n\
+                    WARNING: Using -s implies -e with all privileges\n\
+                    elevated, it may therefore leak privileges into the\n\
+                    container. Use with care.\n\
+  -R, --remount-sys-proc\n\
+                    Remount /sys and /proc if not attaching to the\n\
+                    mount namespace when using -s in order to properly\n\
+                    reflect the correct namespace context. See the\n\
+                    lxc-attach(1) manual page for details.\n\
+      --clear-env   Clear all environment variables before attaching.\n\
+                    The attached shell/program will start with only\n\
+                    container=lxc set.\n\
+      --keep-env    Keep all current environment variables. This\n\
+                    is the current default behaviour, but is likely to\n\
+                    change in the future.\n\
+  -L, --pty-log=FILE\n\
+                    Log pty output to FILE\n\
+  -v, --set-var     Set an additional variable that is seen by the\n\
+                    attached program in the container. May be specified\n\
+                    multiple times.\n\
+      --keep-var    Keep an additional environment variable. Only\n\
+                    applicable if --clear-env is specified. May be used\n\
+                    multiple times.\n\
+  -f, --rcfile=FILE\n\
+                    Load configuration file FILE\n\
+",
+	.options      = my_longopts,
+	.parser       = my_parser,
+	.checker      = NULL,
+	.log_priority = "ERROR",
+	.log_file     = "none",
+};
 
 static int my_parser(struct lxc_arguments *args, int c, char *arg)
 {
@@ -160,65 +192,45 @@ static int my_parser(struct lxc_arguments *args, int c, char *arg)
 	return 0;
 }
 
-static struct lxc_arguments my_args = {
-	.progname = "lxc-attach",
-	.help     = "\
---name=NAME [-- COMMAND]\n\
-\n\
-Execute the specified COMMAND - enter the container NAME\n\
-\n\
-Options :\n\
-  -n, --name=NAME   NAME of the container\n\
-  -e, --elevated-privileges=PRIVILEGES\n\
-                    Use elevated privileges instead of those of the\n\
-                    container. If you don't specify privileges to be\n\
-                    elevated as OR'd list: CAP, CGROUP and LSM (capabilities,\n\
-                    cgroup and restrictions, respectively) then all of them\n\
-                    will be elevated.\n\
-                    WARNING: This may leak privileges into the container.\n\
-                    Use with care.\n\
-  -a, --arch=ARCH   Use ARCH for program instead of container's own\n\
-                    architecture.\n\
-  -s, --namespaces=FLAGS\n\
-                    Don't attach to all the namespaces of the container\n\
-                    but just to the following OR'd list of flags:\n\
-                    MOUNT, PID, UTSNAME, IPC, USER or NETWORK.\n\
-                    WARNING: Using -s implies -e with all privileges\n\
-                    elevated, it may therefore leak privileges into the\n\
-                    container. Use with care.\n\
-  -R, --remount-sys-proc\n\
-                    Remount /sys and /proc if not attaching to the\n\
-                    mount namespace when using -s in order to properly\n\
-                    reflect the correct namespace context. See the\n\
-                    lxc-attach(1) manual page for details.\n\
-      --clear-env   Clear all environment variables before attaching.\n\
-                    The attached shell/program will start with only\n\
-                    container=lxc set.\n\
-      --keep-env    Keep all current environment variables. This\n\
-                    is the current default behaviour, but is likely to\n\
-                    change in the future.\n\
-  -L, --pty-log=FILE\n\
-                    Log pty output to FILE\n\
-  -v, --set-var     Set an additional variable that is seen by the\n\
-                    attached program in the container. May be specified\n\
-                    multiple times.\n\
-      --keep-var    Keep an additional environment variable. Only\n\
-                    applicable if --clear-env is specified. May be used\n\
-                    multiple times.\n\
-  -f, --rcfile=FILE\n\
-                    Load configuration file FILE\n\
-",
-	.options  = my_longopts,
-	.parser   = my_parser,
-	.checker  = NULL,
-};
+static int add_to_simple_array(char ***array, ssize_t *capacity, char *value)
+{
+	ssize_t count = 0;
+
+	if (!array)
+		return -1;
+
+	if (*array)
+		for (; (*array)[count]; count++);
+
+	/* we have to reallocate */
+	if (count >= *capacity - 1) {
+		ssize_t new_capacity = ((count + 1) / 32 + 1) * 32;
+
+		char **new_array = realloc((void*)*array, sizeof(char *) * new_capacity);
+		if (!new_array)
+			return -1;
+
+		memset(&new_array[count], 0, sizeof(char*)*(new_capacity - count));
+
+		*array = new_array;
+		*capacity = new_capacity;
+	}
+
+	if (!(*array))
+		return -1;
+
+	(*array)[count] = value;
+	return 0;
+}
 
 static bool stdfd_is_pty(void)
 {
 	if (isatty(STDIN_FILENO))
 		return true;
+
 	if (isatty(STDOUT_FILENO))
 		return true;
+
 	if (isatty(STDERR_FILENO))
 		return true;
 
@@ -240,23 +252,19 @@ static int lxc_attach_create_log_file(const char *log_file)
 
 int main(int argc, char *argv[])
 {
-	int ret = -1, r;
+	int ret = -1;
 	int wexit = 0;
 	struct lxc_log log;
 	pid_t pid;
 	lxc_attach_options_t attach_options = LXC_ATTACH_OPTIONS_DEFAULT;
 	lxc_attach_command_t command = (lxc_attach_command_t){.program = NULL};
 
-	r = lxc_caps_init();
-	if (r)
+	if (lxc_caps_init())
 		exit(EXIT_FAILURE);
 
-	r = lxc_arguments_parse(&my_args, argc, argv);
-	if (r)
+	if (lxc_arguments_parse(&my_args, argc, argv))
 		exit(EXIT_FAILURE);
 
-	/* Only create log if explicitly instructed */
-	if (my_args.log_file || my_args.log_priority) {
 	log.name = my_args.name;
 	log.file = my_args.log_file;
 	log.level = my_args.log_priority;
@@ -266,14 +274,12 @@ int main(int argc, char *argv[])
 
 	if (lxc_log_init(&log))
 		exit(EXIT_FAILURE);
-	}
 
-	if (geteuid()) {
+	if (geteuid())
 		if (access(my_args.lxcpath[0], O_RDONLY) < 0) {
 			ERROR("You lack access to %s", my_args.lxcpath[0]);
 			exit(EXIT_FAILURE);
 		}
-	}
 
 	struct lxc_container *c = lxc_container_new(my_args.name, my_args.lxcpath[0]);
 	if (!c)