mesh: Fix snprintf return values not being checked

Some versions of the GCC compiler complain when the return value of
snprintf is not checked. This patch cleans up the Mesh JSON parser.

1 files changed, 57 insertions, 31 deletions

diff --git a/mesh/mesh-config-json.c b/mesh/mesh-config-json.c
index f142f0e1f..5bb1e5ce0 100644
--- a/mesh/mesh-config-json.c
+++ b/mesh/mesh-config-json.c
@@ -156,7 +156,7 @@ static json_object *get_element_model(json_object *jnode, int ele_idx,
 						uint32_t mod_id, bool vendor)
 {
 	json_object *jelements, *jelement, *jmodels;
-	int i, num_mods;
+	int i, num_mods, ret;
 	size_t len;
 	char buf[9];
 
@@ -174,13 +174,15 @@ static json_object *get_element_model(json_object *jnode, int ele_idx,
 	if (!num_mods)
 		return NULL;
 
-	if (!vendor) {
-		snprintf(buf, 5, "%4.4x", (uint16_t)mod_id);
-		len = 4;
-	} else {
-		snprintf(buf, 9, "%8.8x", mod_id);
-		len = 8;
-	}
+	if (!vendor)
+		ret = snprintf(buf, 5, "%4.4x", (uint16_t)mod_id);
+	else
+		ret = snprintf(buf, 9, "%8.8x", mod_id);
+
+	if (ret < 0)
+		return NULL;
+
+	len = ret;
 
 	for (i = 0; i < num_mods; ++i) {
 		json_object *jmodel, *jvalue;
@@ -818,7 +820,7 @@ bool mesh_config_model_binding_add(struct mesh_config *cfg, uint16_t ele_addr,
 							uint16_t app_idx)
 {
 	json_object *jnode, *jmodel, *jstring, *jarray = NULL;
-	int ele_idx;
+	int ele_idx, ret;
 	char buf[5];
 
 	if (!cfg)
@@ -826,6 +828,10 @@ bool mesh_config_model_binding_add(struct mesh_config *cfg, uint16_t ele_addr,
 
 	jnode = cfg->jnode;
 
+	ret = snprintf(buf, 5, "%4.4x", app_idx);
+	if (ret < 0)
+		return false;
+
 	ele_idx = get_element_index(jnode, ele_addr);
 	if (ele_idx < 0)
 		return false;
@@ -834,8 +840,6 @@ bool mesh_config_model_binding_add(struct mesh_config *cfg, uint16_t ele_addr,
 	if (!jmodel)
 		return false;
 
-	snprintf(buf, 5, "%4.4x", app_idx);
-
 	json_object_object_get_ex(jmodel, "bind", &jarray);
 	if (jarray && jarray_has_string(jarray, buf, 4))
 		return true;
@@ -863,7 +867,7 @@ bool mesh_config_model_binding_del(struct mesh_config *cfg, uint16_t ele_addr,
 							uint16_t app_idx)
 {
 	json_object *jnode, *jmodel, *jarray;
-	int ele_idx;
+	int ele_idx, ret;
 	char buf[5];
 
 	if (!cfg)
@@ -871,6 +875,10 @@ bool mesh_config_model_binding_del(struct mesh_config *cfg, uint16_t ele_addr,
 
 	jnode = cfg->jnode;
 
+	ret = snprintf(buf, 5, "%4.4x", app_idx);
+	if (ret < 0)
+		return false;
+
 	ele_idx = get_element_index(jnode, ele_addr);
 	if (ele_idx < 0)
 		return false;
@@ -882,8 +890,6 @@ bool mesh_config_model_binding_del(struct mesh_config *cfg, uint16_t ele_addr,
 	if (!json_object_object_get_ex(jmodel, "bind", &jarray))
 		return true;
 
-	snprintf(buf, 5, "%4.4x", app_idx);
-
 	jarray_string_del(jarray, buf, 4);
 
 	if (!json_object_array_length(jarray))
@@ -1415,9 +1421,13 @@ static bool write_uint16_hex(json_object *jobj, const char *desc,
 								uint16_t value)
 {
 	json_object *jstring;
+	int ret;
 	char buf[5];
 
-	snprintf(buf, 5, "%4.4x", value);
+	ret = snprintf(buf, 5, "%4.4x", value);
+	if (ret < 0)
+		return false;
+
 	jstring = json_object_new_string(buf);
 	if (!jstring)
 		return false;
@@ -1430,9 +1440,13 @@ static bool write_uint16_hex(json_object *jobj, const char *desc,
 static bool write_uint32_hex(json_object *jobj, const char *desc, uint32_t val)
 {
 	json_object *jstring;
+	int ret;
 	char buf[9];
 
-	snprintf(buf, 9, "%8.8x", val);
+	ret = snprintf(buf, 9, "%8.8x", val);
+	if (ret < 0)
+		return false;
+
 	jstring = json_object_new_string(buf);
 	if (!jstring)
 		return false;
@@ -1716,22 +1730,24 @@ struct mesh_config *mesh_config_create(const char *cfgdir_name,
 	char uuid_buf[33];
 	char name_buf[PATH_MAX];
 	struct mesh_config *cfg;
-	size_t max_len = strlen(cfgnode_name) + strlen(bak_ext);
+	int ret;
 
 	if (!hex2str((uint8_t *) uuid, 16, uuid_buf, sizeof(uuid_buf)))
 		return NULL;
 
-	snprintf(name_buf, PATH_MAX, "%s/%s", cfgdir_name, uuid_buf);
-
-	if (strlen(name_buf) + max_len >= PATH_MAX)
+	ret = snprintf(name_buf, PATH_MAX, "%s/%s", cfgdir_name, uuid_buf);
+	if (ret < 0)
 		return NULL;
 
 	/* Create a new directory and node.json file */
 	if (mkdir(name_buf, 0755) != 0)
 		return NULL;
 
-	snprintf(name_buf, PATH_MAX, "%s/%s%s", cfgdir_name, uuid_buf,
+	ret = snprintf(name_buf, PATH_MAX, "%s/%s%s", cfgdir_name, uuid_buf,
 								cfgnode_name);
+	if (ret < 0)
+		return NULL;
+
 	l_debug("New node config %s", name_buf);
 
 	cfg = create_config(name_buf, uuid, db_node);
@@ -1904,12 +1920,14 @@ bool mesh_config_model_pub_del(struct mesh_config *cfg, uint16_t addr,
 static void del_page(json_object *jarray, uint8_t page)
 {
 	char buf[3];
-	int i, len;
+	int i, len, ret;
 
 	if (!jarray)
 		return;
 
-	snprintf(buf, 3, "%2.2x", page);
+	ret = snprintf(buf, 3, "%2.2x", page);
+	if (ret < 0)
+		return;
 
 	len = json_object_array_length(jarray);
 
@@ -1931,7 +1949,7 @@ bool mesh_config_comp_page_add(struct mesh_config *cfg, uint8_t page,
 {
 	json_object *jnode, *jstring, *jarray = NULL;
 	char *buf;
-	int len;
+	int len, ret;
 
 	if (!cfg)
 		return false;
@@ -1942,7 +1960,10 @@ bool mesh_config_comp_page_add(struct mesh_config *cfg, uint8_t page,
 
 	len = (size * 2) + 3;
 	buf = l_malloc(len);
-	snprintf(buf, len, "%2.2x", page);
+	ret = snprintf(buf, len, "%2.2x", page);
+	if (ret < 0)
+		return false;
+
 	hex2str(data, size, buf + 2, len - 2);
 
 	if (jarray && jarray_has_string(jarray, buf, len)) {
@@ -1967,12 +1988,16 @@ bool mesh_config_comp_page_mv(struct mesh_config *cfg, uint8_t old, uint8_t nw)
 	uint8_t *data;
 	char *str;
 	char old_buf[3];
-	int i, len, dlen = 0;
+	int i, len, ret, dlen = 0;
 	bool status = true;
 
 	if (!cfg || old == nw)
 		return false;
 
+	ret = snprintf(old_buf, 3, "%2.2x", old);
+	if (ret < 0)
+		return false;
+
 	jnode = cfg->jnode;
 
 	json_object_object_get_ex(jnode, "pages", &jarray);
@@ -1980,7 +2005,6 @@ bool mesh_config_comp_page_mv(struct mesh_config *cfg, uint8_t old, uint8_t nw)
 	if (!jarray)
 		return false;
 
-	snprintf(old_buf, 3, "%2.2x", old);
 	data = l_malloc(MAX_MSG_LEN);
 
 	len = json_object_array_length(jarray);
@@ -2030,8 +2054,9 @@ bool mesh_config_model_sub_add(struct mesh_config *cfg, uint16_t ele_addr,
 		return false;
 
 	if (!sub->virt) {
-		snprintf(buf, 5, "%4.4x", sub->addr.grp);
-		len = 4;
+		len = snprintf(buf, 5, "%4.4x", sub->addr.grp);
+		if (len < 0)
+			return false;
 	} else {
 		hex2str(sub->addr.label, 16, buf, 33);
 		len = 32;
@@ -2084,8 +2109,9 @@ bool mesh_config_model_sub_del(struct mesh_config *cfg, uint16_t ele_addr,
 		return true;
 
 	if (!sub->virt) {
-		snprintf(buf, 5, "%4.4x", sub->addr.grp);
-		len = 4;
+		len = snprintf(buf, 5, "%4.4x", sub->addr.grp);
+		if (len < 0)
+			return false;
 	} else {
 		hex2str(sub->addr.label, 16, buf, 33);
 		len = 32;