X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Futils.c;h=5f40b8afac98ee4d891ed7b4f1961293f4eb8400;hb=3d787920d51a35e74e442c7265be3b13b69ad8e4;hp=c395169d4ba05801cdef49d9bcdfb1fe3ff1c2e7;hpb=76de8e3924fc36e5a3e906741bf640dceb846800;p=tinc

diff --git a/src/utils.c b/src/utils.c
index c395169d..5f40b8af 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -81,6 +81,57 @@ size_t bin2hex(const void *vsrc, char *dst, size_t length) {
 	return length * 2;
 }
 
+char *absolute_path(const char *path) {
+#ifdef HAVE_WINDOWS
+	// Works for nonexistent paths
+	return _fullpath(NULL, path, 0);
+#else
+
+	if(!path || !*path) {
+		return NULL;
+	}
+
+	// If an absolute path was passed, return its copy
+	if(*path == '/') {
+		return xstrdup(path);
+	}
+
+	// Try using realpath. If it fails for any reason
+	// other than that the file was not found, bail out.
+	char *abs = realpath(path, NULL);
+
+	if(abs || errno != ENOENT) {
+		return abs;
+	}
+
+	// Since the file does not exist, we're forced to use a fallback.
+	// Get current working directory and concatenate it with the argument.
+	char cwd[PATH_MAX];
+
+	if(!getcwd(cwd, sizeof(cwd))) {
+		return NULL;
+	}
+
+	// Remove trailing slash if present since we'll be adding our own
+	size_t cwdlen = strlen(cwd);
+
+	if(cwdlen && cwd[cwdlen - 1] == '/') {
+		cwd[cwdlen - 1] = '\0';
+	}
+
+	// We don't do any normalization because it's complicated, and the payoff is small.
+	// If user passed something like '.././../foo' — that's their choice; fopen works either way.
+	xasprintf(&abs, "%s/%s", cwd, path);
+
+	if(strlen(abs) >= PATH_MAX) {
+		free(abs);
+		abs = NULL;
+	}
+
+	return abs;
+#endif
+}
+
 size_t b64decode_tinc(const char *src, void *dst, size_t length) {
 	size_t i;
 	uint32_t triplet = 0;