Introduce utility safe string handling functions.

We have our versions of strdup, strlcat, and strlcpy.
This means we can avoid using snprintf() in many cases
(saving cycles), and we can get safer checks.  We use
the platform supplied versions of these if they exist
(wrapping with nni_xxx versions.)

2 files changed, 9 insertions, 3 deletions

diff --git a/src/platform/posix/posix_ipc.c b/src/platform/posix/posix_ipc.c
index 2daec4ea..f0a9a973 100644
--- a/src/platform/posix/posix_ipc.c
+++ b/src/platform/posix/posix_ipc.c
@@ -98,9 +98,14 @@ nni_plat_ipc_remove_stale(const char *path)
 	int                fd;
 	int                rv;
 	struct sockaddr_un sun;
+	size_t             sz;
 
 	sun.sun_family = AF_UNIX;
-	snprintf(sun.sun_path, sizeof(sun.sun_path), "%s", path);
+	sz             = sizeof(sun.sun_path);
+
+	if (nni_strlcpy(sun.sun_path, path, sz) >= sz) {
+		return (NNG_EADDRINVAL);
+	}
 
 	if ((fd = socket(AF_UNIX, NNI_STREAM_SOCKTYPE, 0)) < 0) {
 		return (nni_plat_errno(errno));
diff --git a/src/platform/posix/posix_sockaddr.c b/src/platform/posix/posix_sockaddr.c
index 21a2b863..ea630b01 100644
--- a/src/platform/posix/posix_sockaddr.c
+++ b/src/platform/posix/posix_sockaddr.c
@@ -31,6 +31,7 @@ nni_posix_nn2sockaddr(void *sa, const nni_sockaddr *na)
 	const nng_sockaddr_in *  nsin;
 	const nng_sockaddr_in6 * nsin6;
 	const nng_sockaddr_path *nspath;
+	size_t                   sz;
 
 	switch (na->s_un.s_family) {
 	case NNG_AF_INET:
@@ -59,8 +60,8 @@ nni_posix_nn2sockaddr(void *sa, const nni_sockaddr *na)
 		nspath = &na->s_un.s_path;
 		memset(spath, 0, sizeof(*spath));
 		// Make sure that the path fits!
-		if (snprintf(spath->sun_path, sizeof(spath->sun_path), "%s",
-		        nspath->sa_path) >= sizeof(spath->sun_path)) {
+		sz = sizeof(spath->sun_path);
+		if (nni_strlcpy(spath->sun_path, nspath->sa_path, sz) >= sz) {
 			return (-1);
 		}
 		spath->sun_family = PF_UNIX;