X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Futils.c;h=8655e2beb848fd0ed81456ea650ac2180f174fb0;hb=2f2bda4d1953617b945f1222e008cb53edee162a;hp=c2f4333fc783f3172dcf77bc2046b63a9de287d6;hpb=0289162552cd85375605044c696e2a3294e7aa9a;p=tinc

diff --git a/src/utils.c b/src/utils.c
index c2f4333f..8655e2be 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -18,6 +18,8 @@
     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
+#include <assert.h>
+
 #include "logger.h"
 #include "system.h"
 #include "utils.h"
@@ -79,13 +81,64 @@ 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;
 	unsigned char *udst = (unsigned char *)dst;
 
 	for(i = 0; i < length && src[i]; i++) {
-		triplet |= base64_decode[src[i] & 0xff] << (6 * (i & 3));
+		triplet |= (uint32_t)(base64_decode[src[i] & 0xff] << (6 * (i & 3)));
 
 		if((i & 3) == 3) {
 			if(triplet & 0xff000000U) {
@@ -320,3 +373,7 @@ FILE *fopenmask(const char *filename, const char *mode, mode_t perms) {
 	return f;
 }
 
+bool string_eq(const char *first, const char *second) {
+	return !first == !second &&
+	       !(first && second && strcmp(first, second));
+}