uxc: clean up error handling

Use negative return value to indicate errors and positive return value
for quantitative information.
Use 'bool' return type for some functions which never throw an error.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

uxc.c

@@ -124,7 +124,7 @@ static int usage(void) {
 	printf("\tenable <conf>\t\t\t\tstart container <conf> on boot\n");
 	printf("\tdisable <conf>\t\t\t\tdon't start container <conf> on boot\n");
 	printf("\tdelete <conf> [--force]\t\t\tdelete <conf>\n");
-	return EINVAL;
+	return -EINVAL;
 }
 
 enum {
@@ -161,7 +161,7 @@ static int conf_load(bool load_settings)
 	struct blob_buf *target;
 
 	if (asprintf(&globstr, "%s/%s*.json", UXC_ETC_CONFDIR, load_settings?"settings/":"") == -1)
-		return ENOMEM;
+		return -ENOMEM;
 
 	res = glob(globstr, gl_flags, NULL, &gl);
 	if (res == 0)
@@ -172,7 +172,7 @@ static int conf_load(bool load_settings)
 	if (!stat(UXC_VOL_CONFDIR, &sb)) {
 		if (sb.st_mode & S_IFDIR) {
 			if (asprintf(&globstr, "%s/%s*.json",  UXC_VOL_CONFDIR, load_settings?"settings/":"") == -1)
-				return ENOMEM;
+				return -ENOMEM;
 
 			res = glob(globstr, gl_flags, NULL, &gl);
 			free(globstr);
@@ -265,7 +265,6 @@ static void settings_free(void)
 		free(item);
 	}
 
-	blob_buf_free(&settingsbuf);
 	return;
 }
 
@@ -429,7 +428,7 @@ static int runtime_load(void)
 	avl_init(&runtime, avl_strcmp, false, NULL);
 	if (ubus_lookup_id(ctx, "container", &id) ||
 		ubus_invoke(ctx, id, "list", NULL, list_cb, &runtime, 3000))
-		return EIO;
+		return -EIO;
 
 	avl_for_each_element_safe(&runtime, item, avl, tmp)
 		get_ocistate(&item->ocistate, item->jail_name);
@@ -457,12 +456,12 @@ static inline int setup_tios(int fd, struct termios *oldtios)
 	struct termios newtios;
 
 	if (!isatty(fd)) {
-		return -1;
+		return -EIO;
 	}
 
 	/* Get current termios */
-	if (tcgetattr(fd, oldtios))
-		return -1;
+	if (tcgetattr(fd, oldtios) < 0)
+		return -errno;
 
 	newtios = *oldtios;
 
@@ -476,8 +475,8 @@ static inline int setup_tios(int fd, struct termios *oldtios)
 	newtios.c_cc[VTIME] = 0;
 
 	/* Set new attributes */
-	if (tcsetattr(fd, TCSAFLUSH, &newtios))
-	        return -1;
+	if (tcsetattr(fd, TCSAFLUSH, &newtios) < 0)
+	        return -errno;
 
 	return 0;
 }
@@ -537,7 +536,7 @@ static int uxc_attach(const char *container_name)
 	ctx = ubus_connect(NULL);
 	if (!ctx) {
 		fprintf(stderr, "can't connect to ubus!\n");
-		return -1;
+		return -ECONNREFUSED;
 	}
 
 	/* open pseudo-terminal pair */
@@ -545,7 +544,7 @@ static int uxc_attach(const char *container_name)
 	if (client_fd < 0) {
 		fprintf(stderr, "can't create virtual console!\n");
 		ubus_free(ctx);
-		return -1;
+		return -EIO;
 	}
 	setup_tios(client_fd, &oldtermios);
 	grantpt(client_fd);
@@ -555,7 +554,7 @@ static int uxc_attach(const char *container_name)
 		fprintf(stderr, "can't open virtual console!\n");
 		close(client_fd);
 		ubus_free(ctx);
-		return -1;
+		return -EIO;
 	}
 	setup_tios(server_fd, &oldtermios);
 
@@ -565,7 +564,7 @@ static int uxc_attach(const char *container_name)
 		close(server_fd);
 		close(client_fd);
 		ubus_free(ctx);
-		return -1;
+		return -EIO;
 	}
 	setup_tios(tty_fd, &oldtermios);
 
@@ -582,7 +581,7 @@ static int uxc_attach(const char *container_name)
 		close(client_fd);
 		blob_buf_free(&req);
 		ubus_free(ctx);
-		return -2;
+		return -ENXIO;
 	}
 
 	close(server_fd);
@@ -632,7 +631,7 @@ static int uxc_state(char *name)
 	if (ocistate) {
 		state = blobmsg_format_json_indent(ocistate, true, 0);
 		if (!state)
-			return 1;
+			return -ENOMEM;
 
 		printf("%s\n", state);
 		free(state);
@@ -656,7 +655,7 @@ static int uxc_state(char *name)
 	}
 
 	if (!bundle)
-		return ENOENT;
+		return -ENOENT;
 
 	blob_buf_init(&buf, 0);
 	blobmsg_add_string(&buf, "ociVersion", OCI_VERSION_STRING);
@@ -667,7 +666,7 @@ static int uxc_state(char *name)
 	tmp = blobmsg_format_json_indent(buf.head, true, 0);
 	if (!tmp) {
 		blob_buf_free(&buf);
-		return ENOMEM;
+		return -ENOMEM;
 	}
 
 	printf("%s\n", tmp);
@@ -761,7 +760,7 @@ static int uxc_list(void)
 		tmp = blobmsg_format_json_indent(buf.head, true, 0);
 		if (!tmp) {
 			blob_buf_free(&buf);
-			return ENOMEM;
+			return -ENOMEM;
 		}
 		printf("%s\n", tmp);
 		free(tmp);
@@ -777,7 +776,7 @@ static int uxc_exists(char *name)
 	rsstate = avl_find_element(&runtime, name, rsstate, avl);
 
 	if (rsstate && (rsstate->running))
-		return EEXIST;
+		return -EEXIST;
 
 	return 0;
 }
@@ -786,7 +785,7 @@ static int uxc_create(char *name, bool immediately)
 {
 	static struct blob_buf req;
 	struct blob_attr *cur, *tb[__CONF_MAX];
-	int rem, ret;
+	int rem, ret = 0;
 	uint32_t id;
 	struct settings *usettings = NULL;
 	char *path = NULL, *jailname = NULL, *pidfile = NULL, *tmprwsize = NULL, *writepath = NULL;
@@ -807,7 +806,7 @@ static int uxc_create(char *name, bool immediately)
 	}
 
 	if (!found)
-		return ENOENT;
+		return -ENOENT;
 
 	path = blobmsg_get_string(tb[CONF_PATH]);
 
@@ -862,17 +861,16 @@ static int uxc_create(char *name, bool immediately)
 		char *tmp;
 		tmp = blobmsg_format_json_indent(req.head, true, 1);
 		if (!tmp)
-			return ENOMEM;
+			return -ENOMEM;
 
 		fprintf(stderr, "adding container to procd:\n\t%s\n", tmp);
 		free(tmp);
 	}
 
-	ret = 0;
 	if (ubus_lookup_id(ctx, "container", &id) ||
 		ubus_invoke(ctx, id, "add", req.head, NULL, NULL, 3000)) {
 		blob_buf_free(&req);
-		ret = EIO;
+		ret = -EIO;
 	}
 
 	return ret;
@@ -891,10 +889,10 @@ static int uxc_start(const char *name, bool console)
 	}
 
 	if (asprintf(&objname, "container.%s", name) == -1)
-		return ENOMEM;
+		return -ENOMEM;
 
 	if (ubus_lookup_id(ctx, objname, &id))
-		return ENOENT;
+		return -ENOENT;
 
 	free(objname);
 	return ubus_invoke(ctx, id, "start", NULL, NULL, NULL, 3000);
@@ -923,27 +921,27 @@ static int uxc_kill(char *name, int signal)
 	}
 
 	if (!found)
-		return ENOENT;
+		return -ENOENT;
 
 	rsstate = avl_find_element(&runtime, name, rsstate, avl);
 
 	if (!rsstate || !(rsstate->running))
-		return ENOENT;
+		return -ENOENT;
 
 	blob_buf_init(&req, 0);
 	blobmsg_add_u32(&req, "signal", signal);
 	blobmsg_add_string(&req, "name", name);
 
 	if (asprintf(&objname, "container.%s", name) == -1)
-		return ENOMEM;
+		return -ENOMEM;
 
 	ret = ubus_lookup_id(ctx, objname, &id);
 	free(objname);
 	if (ret)
-		return ENOENT;
+		return -ENOENT;
 
 	if (ubus_invoke(ctx, id, "kill", req.head, NULL, NULL, 3000))
-		return EIO;
+		return -EIO;
 
 	return 0;
 }
@@ -980,22 +978,22 @@ static int uxc_set(char *name, char *path, signed char autostart, char *pidfile,
 	}
 
 	if (cfname && path)
-		return EEXIST;
+		return -EEXIST;
 
 	if (!cfname && !path)
-		return ENOENT;
+		return -ENOENT;
 
 	if (path) {
 		if (stat(path, &sb) == -1)
-			return ENOENT;
+			return -ENOENT;
 
 		if ((sb.st_mode & S_IFMT) != S_IFDIR)
-			return ENOTDIR;
+			return -ENOTDIR;
 	}
 
 	usettings = avl_find_element(&settings, blobmsg_get_string(tb[CONF_NAME]), usettings, avl);
 	if (path && usettings)
-		return EIO;
+		return -EIO;
 
 	if (usettings) {
 		sfname = usettings->fname;
@@ -1017,14 +1015,14 @@ static int uxc_set(char *name, char *path, signed char autostart, char *pidfile,
 		ret = mkdir(confdir, 0755);
 
 		if (ret && errno != EEXIST)
-			return ret;
+			return -errno;
 
 		if (asprintf(&fname, "%s/%s.json", confdir, name) == -1)
-			return ENOMEM;
+			return -ENOMEM;
 
 		f = open(fname, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 		if (f < 0)
-			return errno;
+			return -errno;
 
 		free(fname);
 	} else {
@@ -1037,22 +1035,22 @@ static int uxc_set(char *name, char *path, signed char autostart, char *pidfile,
 			*t2 = '\0';
 
 			if (asprintf(&t2, "%s/settings", t1, name) == -1)
-				return ENOMEM;
+				return -ENOMEM;
 
 			ret = mkdir(t2, 0755);
 			if (ret && ret != EEXIST)
-				return ret;
+				return -ret;
 
 			free(t2);
 			if (asprintf(&t2, "%s/settings/%s.json", t1, name) == -1)
-				return ENOMEM;
+				return -ENOMEM;
 
 			free(t1);
 			f = open(t2, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 			free(t2);
 		}
 		if (f < 0)
-			return errno;
+			return -errno;
 	}
 
 	blob_buf_init(&req, 0);
@@ -1096,7 +1094,7 @@ static int uxc_set(char *name, char *path, signed char autostart, char *pidfile,
 	blob_buf_free(&req);
 	close(f);
 
-	return 0;
+	return 1;
 }
 
 enum {
@@ -1118,7 +1116,7 @@ static const struct blobmsg_policy block_info_policy[__BLOCK_INFO_MAX] = {
 
 
 /* check if device 'devname' is mounted according to blockd */
-static int checkblock(const char *uuid)
+static bool checkblock(const char *uuid)
 {
 	struct blob_attr *tb[__BLOCK_INFO_MAX];
 	struct blob_attr *cur;
@@ -1131,10 +1129,10 @@ static int checkblock(const char *uuid)
 			continue;
 
 		if (!strcmp(uuid, blobmsg_get_string(tb[BLOCK_INFO_UUID])))
-			return 0;
+			return false;
 	}
 
-	return 1;
+	return true;
 }
 
 enum {
@@ -1184,17 +1182,17 @@ static const char *resolveuuid(const char *volname)
 };
 
 /* check status of each required volume */
-static int checkvolumes(struct blob_attr *volumes)
+static bool checkvolumes(struct blob_attr *volumes)
 {
 	struct blob_attr *cur;
 	int rem;
 
 	blobmsg_for_each_attr(cur, volumes, rem) {
 		if (checkblock(resolveuuid(blobmsg_get_string(cur))))
-			return 1;
+			return true;
 	}
 
-	return 0;
+	return false;
 }
 
 static void block_cb(struct ubus_request *req, int type, struct blob_attr *msg)
@@ -1220,15 +1218,15 @@ static int uxc_boot(void)
 
 	ret = ubus_lookup_id(ctx, "block", &id);
 	if (ret)
-		return ENOENT;
+		return -ENOENT;
 
 	ret = ubus_invoke(ctx, id, "info", NULL, block_cb, NULL, 3000);
 	if (ret)
-		return ENXIO;
+		return -ENXIO;
 
 	ret = ubus_lookup_id(ctx, "uci", &id);
 	if (ret)
-		return ENOENT;
+		return -ENOENT;
 
 	blob_buf_init(&req, 0);
 	blobmsg_add_string(&req, "config", "fstab");
@@ -1236,7 +1234,7 @@ static int uxc_boot(void)
 
 	ret = ubus_invoke(ctx, id, "get", req.head, fstab_cb, NULL, 3000);
 	if (ret)
-		return ENXIO;
+		return ret;
 
 	blobmsg_for_each_attr(cur, blob_data(conf.head), rem) {
 		blobmsg_parse(conf_policy, __CONF_MAX, tb, blobmsg_data(cur), blobmsg_len(cur));
@@ -1270,7 +1268,9 @@ static int uxc_boot(void)
 		if (uxc_exists(name))
 			continue;
 
-		ret += uxc_create(name, true);
+		if (uxc_create(name, true))
+			++ret;
+
 		free(name);
 	}
 
@@ -1302,7 +1302,7 @@ static int uxc_delete(char *name, bool force)
 	}
 
 	if (!cfname)
-		return ENOENT;
+		return -ENOENT;
 
 	rsstate = avl_find_element(&runtime, name, rsstate, avl);
 
@@ -1313,7 +1313,7 @@ static int uxc_delete(char *name, bool force)
 				goto errout;
 
 		} else {
-			ret = EWOULDBLOCK;
+			ret = -EWOULDBLOCK;
 			goto errout;
 		}
 	}
@@ -1329,7 +1329,7 @@ static int uxc_delete(char *name, bool force)
 
 		if (ubus_invoke(ctx, id, "delete", req.head, NULL, NULL, 3000)) {
 			blob_buf_free(&req);
-			ret = EIO;
+			ret = -EIO;
 			goto errout;
 		}
 	}
@@ -1340,23 +1340,23 @@ static int uxc_delete(char *name, bool force)
 
 	if (sfname) {
 		if (stat(sfname, &sb) == -1) {
-			ret = ENOENT;
+			ret = -ENOENT;
 			goto errout;
 		}
 
 		if (unlink(sfname) == -1) {
-			ret = errno;
+			ret = -errno;
 			goto errout;
 		}
 	}
 
 	if (stat(cfname, &sb) == -1) {
-		ret = ENOENT;
+		ret = -ENOENT;
 		goto errout;
 	}
 
 	if (unlink(cfname) == -1)
-		ret = errno;
+		ret = -errno;
 
 errout:
 	return ret;
@@ -1367,6 +1367,7 @@ static void reload_conf(void)
 	blob_buf_free(&conf);
 	conf_load(false);
 	settings_free();
+	blob_buf_free(&settingsbuf);
 	conf_load(true);
 	settings_add();
 }
@@ -1374,7 +1375,7 @@ static void reload_conf(void)
 int main(int argc, char **argv)
 {
 	enum uxc_cmd cmd = CMD_UNKNOWN;
-	int ret = EINVAL;
+	int ret = -EINVAL;
 	char *bundle = NULL;
 	char *pidfile = NULL;
 	char *tmprwsize = NULL;
@@ -1391,18 +1392,23 @@ int main(int argc, char **argv)
 
 	ctx = ubus_connect(NULL);
 	if (!ctx)
-		return ENODEV;
+		return -ENODEV;
 
 	ret = conf_load(false);
-	if (ret)
+	if (ret < 0)
 		goto out;
 
-	conf_load(true);
-	settings_add();
+	ret = conf_load(true);
+	if (ret < 0)
+		goto conf_out;
+
+	ret = settings_add();
+	if (ret < 0)
+		goto settings_out;
 
 	ret = runtime_load();
 	if (ret)
-		goto conf_out;
+		goto settings_avl_out;
 
 	while (true) {
 		int option_index = 0;
@@ -1550,10 +1556,11 @@ int main(int argc, char **argv)
 				goto runtime_out;
 
 			ret = uxc_set(argv[optind + 1], bundle, autostart, pidfile, tmprwsize, writepath, requiredmounts);
-			if (ret)
+			if (ret < 0)
 				goto runtime_out;
 
-			reload_conf();
+			if (ret > 0)
+				reload_conf();
 
 			ret = uxc_create(argv[optind + 1], false);
 			break;
@@ -1565,16 +1572,20 @@ int main(int argc, char **argv)
 	goto runtime_out;
 
 usage_out:
-	usage();
+	ret = usage();
 runtime_out:
 	runtime_free();
+settings_avl_out:
+	settings_free();
+settings_out:
+	blob_buf_free(&settingsbuf);
 conf_out:
 	blob_buf_free(&conf);
 out:
 	ubus_free(ctx);
 
-	if (ret != 0)
-		fprintf(stderr, "uxc error: %s\n", strerror(ret));
+	if (ret < 0)
+		fprintf(stderr, "uxc error: %s\n", strerror(-ret));
 
 	return ret;
 }