Proper strncpy null termination

3 files changed, 15 insertions, 6 deletions

diff --git a/kms/client/kms_client.c b/kms/client/kms_client.c
index 57c6ccf..1c8f634 100644
--- a/kms/client/kms_client.c
+++ b/kms/client/kms_client.c
@@ -127,7 +127,7 @@ static bool create_socket_path(char *output_path, size_t output_path_size) {
     return true;
 }
 
-static void strncpy_safe(char *dst, const char *src, int len) {
+static void string_copy(char *dst, const char *src, int len) {
     int src_len = strlen(src);
     int min_len = src_len;
     if(len - 1 < min_len)
@@ -232,7 +232,7 @@ int gsr_kms_client_init(gsr_kms_client *self, const char *card_path) {
     }
 
     local_addr.sun_family = AF_UNIX;
-    strncpy_safe(local_addr.sun_path, self->initial_socket_path, sizeof(local_addr.sun_path));
+    string_copy(local_addr.sun_path, self->initial_socket_path, sizeof(local_addr.sun_path));
 
     const mode_t prev_mask = umask(0000);
     const int bind_res = bind(self->initial_socket_fd, (struct sockaddr*)&local_addr, sizeof(local_addr.sun_family) + strlen(local_addr.sun_path));
diff --git a/kms/server/kms_server.c b/kms/server/kms_server.c
index 09deaab..2eaa1ed 100644
--- a/kms/server/kms_server.c
+++ b/kms/server/kms_server.c
@@ -379,7 +379,7 @@ static double clock_get_monotonic_seconds(void) {
     return (double)ts.tv_sec + (double)ts.tv_nsec * 0.000000001;
 }
 
-static void strncpy_safe(char *dst, const char *src, int len) {
+static void string_copy(char *dst, const char *src, int len) {
     int src_len = strlen(src);
     int min_len = src_len;
     if(len - 1 < min_len)
@@ -444,7 +444,7 @@ int main(int argc, char **argv) {
     while(clock_get_monotonic_seconds() - start_time < connect_timeout_sec) {
         struct sockaddr_un remote_addr = {0};
         remote_addr.sun_family = AF_UNIX;
-        strncpy_safe(remote_addr.sun_path, domain_socket_path, sizeof(remote_addr.sun_path));
+        string_copy(remote_addr.sun_path, domain_socket_path, sizeof(remote_addr.sun_path));
         // TODO: Check if parent disconnected
         if(connect(socket_fd, (struct sockaddr*)&remote_addr, sizeof(remote_addr.sun_family) + strlen(remote_addr.sun_path)) == -1) {
             if(errno == ECONNREFUSED || errno == ENOENT) {
diff --git a/src/utils.c b/src/utils.c
index 7dd1890..40d652e 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -414,9 +414,18 @@ static bool try_card_has_valid_plane(const char *card_path) {
     return false;
 }
 
+static void string_copy(char *dst, const char *src, int len) {
+    int src_len = strlen(src);
+    int min_len = src_len;
+    if(len - 1 < min_len)
+        min_len = len - 1;
+    memcpy(dst, src, min_len);
+    dst[min_len] = '\0';
+}
+
 bool gsr_get_valid_card_path(gsr_egl *egl, char *output) {
     if(egl->dri_card_path) {
-        strncpy(output, egl->dri_card_path, 127);
+        string_copy(output, egl->dri_card_path, 127);
         return try_card_has_valid_plane(output);
     }
 
@@ -435,7 +444,7 @@ bool gsr_card_path_get_render_path(const char *card_path, char *render_path) {
 
     char *render_path_tmp = drmGetRenderDeviceNameFromFd(fd);
     if(render_path_tmp) {
-        strncpy(render_path, render_path_tmp, 127);
+        string_copy(render_path, render_path_tmp, 127);
         free(render_path_tmp);
         close(fd);
         return true;