git-format-patch should show the correct version

[git.git] / daemon.c

diff --git a/daemon.c b/daemon.c
index 91b9656..539f6e8 100644 (file)
--- a/daemon.c
+++ b/daemon.c
@@ -82,9 +82,63 @@ static void loginfo(const char *err, ...)
        va_end(params);
 }
 
+static int avoid_alias(char *p)
+{
+       int sl, ndot;
+
+       /* 
+        * This resurrects the belts and suspenders paranoia check by HPA
+        * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
+        * does not do getcwd() based path canonicalizations.
+        *
+        * sl becomes true immediately after seeing '/' and continues to
+        * be true as long as dots continue after that without intervening
+        * non-dot character.
+        */
+       if (!p || (*p != '/' && *p != '~'))
+               return -1;
+       sl = 1; ndot = 0;
+       p++;
+
+       while (1) {
+               char ch = *p++;
+               if (sl) {
+                       if (ch == '.')
+                               ndot++;
+                       else if (ch == '/') {
+                               if (ndot < 3)
+                                       /* reject //, /./ and /../ */
+                                       return -1;
+                               ndot = 0;
+                       }
+                       else if (ch == 0) {
+                               if (0 < ndot && ndot < 3)
+                                       /* reject /.$ and /..$ */
+                                       return -1;
+                               return 0;
+                       }
+                       else
+                               sl = ndot = 0;
+               }
+               else if (ch == 0)
+                       return 0;
+               else if (ch == '/') {
+                       sl = 1;
+                       ndot = 0;
+               }
+       }
+}
+
 static char *path_ok(char *dir)
 {
-       char *path = enter_repo(dir, strict_paths);
+       char *path;
+
+       if (avoid_alias(dir)) {
+               logerror("'%s': aliased", dir);
+               return NULL;
+       }
+
+       path = enter_repo(dir, strict_paths);
 
        if (!path) {
                logerror("'%s': unable to chdir or not a git archive", dir);
@@ -96,9 +150,11 @@ static char *path_ok(char *dir)
                int pathlen = strlen(path);
 
                /* The validation is done on the paths after enter_repo
-                * canonicalization, so whitelist should be written in
-                * terms of real pathnames (i.e. after ~user is expanded
-                * and symlinks resolved).
+                * appends optional {.git,.git/.git} and friends, but 
+                * it does not use getcwd().  So if your /pub is
+                * a symlink to /mnt/pub, you can whitelist /pub and
+                * do not have to say /mnt/pub.
+                * Do not say /pub/.
                 */
                for ( pp = ok_paths ; *pp ; pp++ ) {
                        int len = strlen(*pp);