[LEDE-DEV] [PATCH rpcd 2/2] sys: Check return values of chdir and write

[Florian Fainelli]

Fixes the following warnings:

rpcd/sys.c: In function 'rpc_cgi_password_set':
rpcd/sys.c:116:8: error: ignoring return value of 'chdir', declared with attribute warn_unused_result [-Werror=unused-result]
   chdir("/");
        ^
rpcd/sys.c:125:8: error: ignoring return value of 'write', declared with attribute warn_unused_result [-Werror=unused-result]
   write(fds[1], blobmsg_data(tb[RPC_P_PASSWORD]),
        ^
rpcd/sys.c:127:8: error: ignoring return value of 'write', declared with attribute warn_unused_result [-Werror=unused-result]
   write(fds[1], "\n", 1);
        ^
rpcd/sys.c:131:8: error: ignoring return value of 'write', declared with attribute warn_unused_result [-Werror=unused-result]
   write(fds[1], blobmsg_data(tb[RPC_P_PASSWORD]),
        ^
rpcd/sys.c:133:8: error: ignoring return value of 'write', declared with attribute warn_unused_result [-Werror=unused-result]
   write(fds[1], "\n", 1);
        ^
cc1: all warnings being treated as errors

Signed-off-by: Florian Fainelli <f.fainelli at gmail.com>
---
 sys.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/sys.c b/sys.c
index b90aa6b894ab..3691dfbd1f50 100644
--- a/sys.c
+++ b/sys.c
@@ -76,6 +76,8 @@ rpc_cgi_password_set(struct ubus_context *ctx, struct ubus_object *obj,
 	int fd, fds[2];
 	struct stat s;
 	struct blob_attr *tb[__RPC_P_MAX];
+	ssize_t n;
+	int ret;
 
 	blobmsg_parse(rpc_password_policy, __RPC_P_MAX, tb,
 	              blob_data(msg), blob_len(msg));
@@ -113,7 +115,9 @@ rpc_cgi_password_set(struct ubus_context *ctx, struct ubus_object *obj,
 			close(fd);
 		}
 
-		chdir("/");
+		ret = chdir("/");
+		if (ret < 0)
+			return rpc_errno_status();
 
 		if (execl("/usr/bin/passwd", "/usr/bin/passwd",
 		          blobmsg_data(tb[RPC_P_USER]), NULL))
@@ -122,15 +126,24 @@ rpc_cgi_password_set(struct ubus_context *ctx, struct ubus_object *obj,
 	default:
 		close(fds[0]);
 
-		write(fds[1], blobmsg_data(tb[RPC_P_PASSWORD]),
+		n = write(fds[1], blobmsg_data(tb[RPC_P_PASSWORD]),
 		              blobmsg_data_len(tb[RPC_P_PASSWORD]) - 1);
-		write(fds[1], "\n", 1);
+		if (n < 0)
+			return rpc_errno_status();
+
+		n = write(fds[1], "\n", 1);
+		if (n < 0)
+			return rpc_errno_status();
 
 		usleep(100 * 1000);
 
-		write(fds[1], blobmsg_data(tb[RPC_P_PASSWORD]),
+		n = write(fds[1], blobmsg_data(tb[RPC_P_PASSWORD]),
 		              blobmsg_data_len(tb[RPC_P_PASSWORD]) - 1);
-		write(fds[1], "\n", 1);
+		if (n < 0)
+			return rpc_errno_status();
+		n = write(fds[1], "\n", 1);
+		if (n < 0)
+			return rpc_errno_status();
 
 		close(fds[1]);
 
-- 
2.9.3