cgmnlm

commit cb63b8ddf093711607ff98e933d4bd04154a854b
parent ec88f4558c48b3eece906143867dfba6d81e5e49
Author: Giuseppe Lumia <g.lumia@outlook.com>
Date:   Wed, 11 Nov 2020 23:52:03 +0100

Fix bug on mkdirs calls

On some systems dirname uses a static string for its return value, so
we were calling mkdirs recursively on a string that was continuosly changing.

A check was also added after the `snprintf` to make sure there's no
information loss since there is no limit to the length of the string
returned by `get_data_pathfmt`.

Closes #48.

Diffstat:
M
src/gmnlm.c
 | 
18
++++++++++++++----
M
src/tofu.c
 | 
11
++++++++---

2 files changed, 22 insertions(+), 7 deletions(-)
diff --git a/src/gmnlm.c b/src/gmnlm.c
@@ -154,8 +154,13 @@ save_bookmark(struct browser *browser)
 {
 	char *path_fmt = get_data_pathfmt();
 	static char path[PATH_MAX+1];
-	snprintf(path, sizeof(path), path_fmt, "bookmarks.gmi");
-	if (mkdirs(dirname(path), 0755) != 0) {
+	static char dname[PATH_MAX+1];
+	size_t n;
+
+	n = snprintf(path, sizeof(path), path_fmt, "bookmarks.gmi");
+	assert(n < sizeof(path));
+	strncpy(dname, dirname(path), sizeof(dname));
+	if (mkdirs(dname, 0755) != 0) {
 		snprintf(path, sizeof(path), path_fmt, "bookmarks.gmi");
 		free(path_fmt);
 		fprintf(stderr, "Error creating directory %s: %s\n",
@@ -190,8 +195,13 @@ open_bookmarks(struct browser *browser)
 {
 	char *path_fmt = get_data_pathfmt();
 	static char path[PATH_MAX+1];
-	snprintf(path, sizeof(path), path_fmt, "bookmarks.gmi");
-	if (mkdirs(dirname(path), 0755) != 0) {
+	static char dname[PATH_MAX+1];
+	size_t n;
+
+	n = snprintf(path, sizeof(path), path_fmt, "bookmarks.gmi");
+	assert(n < sizeof(path));
+	strncpy(dname, dirname(path), sizeof(dname));
+	if (mkdirs(dname, 0755) != 0) {
 		snprintf(path, sizeof(path), path_fmt, "bookmarks.gmi");
 		free(path_fmt);
 		fprintf(stderr, "Error creating directory %s: %s\n",
diff --git a/src/tofu.c b/src/tofu.c
@@ -157,10 +157,15 @@ gemini_tofu_init(struct gemini_tofu *tofu,
 		{.var = "HOME", .path = "/.local/share/gemini/%s"}
 	};
 	char *path_fmt = getpath(paths, sizeof(paths) / sizeof(paths[0]));
-	snprintf(tofu->known_hosts_path, sizeof(tofu->known_hosts_path),
+	char dname[PATH_MAX+1];
+	size_t n = 0;
+
+	n = snprintf(tofu->known_hosts_path, sizeof(tofu->known_hosts_path),
 			path_fmt, "known_hosts");
+	assert(n < sizeof(tofu->known_hosts_path));
 
-	if (mkdirs(dirname(tofu->known_hosts_path), 0755) != 0) {
+	strncpy(dname, dirname(tofu->known_hosts_path), sizeof(dname));
+	if (mkdirs(dname, 0755) != 0) {
 		snprintf(tofu->known_hosts_path, sizeof(tofu->known_hosts_path),
 				path_fmt, "known_hosts");
 		fprintf(stderr, "Error creating directory %s: %s\n",
@@ -182,7 +187,7 @@ gemini_tofu_init(struct gemini_tofu *tofu,
 	if (!f) {
 		return;
 	}
-	size_t n = 0;
+	n = 0;
 	char *line = NULL;
 	while (getline(&line, &n, f) != -1) {
 		struct known_host *host = calloc(1, sizeof(struct known_host));