Merge branch 'jg/credential-cache-chdir-to-sockdir'

The "credential-cache" daemon process used to run in whatever
directory it happened to start in, but this made umount(2)ing the
filesystem that houses the repository harder; now the process
chdir()s to the directory that house its own socket on startup.

* jg/credential-cache-chdir-to-sockdir:
credential-cache--daemon: change to the socket dir on startup
credential-cache--daemon: disallow relative socket path
credential-cache--daemon: refactor check_socket_directory

diff --git a/Documentation/git-credential-cache.txt b/Documentation/git-credential-cache.txt
index 89b730632d603771f36d2c93722f57fbecb1b313..96208f822e0995f97664423038abe1f406431986 100644 (file)
--- a/Documentation/git-credential-cache.txt
+++ b/Documentation/git-credential-cache.txt
@@ -36,7 +36,7 @@ OPTIONS
        cache daemon if one is not started). Defaults to
        `~/.git-credential-cache/socket`. If your home directory is on a
        network-mounted filesystem, you may need to change this to a
-       local filesystem.
+       local filesystem. You must specify an absolute path.
 
 CONTROLLING THE DAEMON
 ----------------------

diff --git a/credential-cache--daemon.c b/credential-cache--daemon.c
index cc65a9c0d342aa51d4b307fe10c626d940e2f211..caef21e4fc91898f209709f723de1df5afc66a66 100644 (file)
--- a/credential-cache--daemon.c
+++ b/credential-cache--daemon.c
@@ -215,7 +215,7 @@ static const char permissions_advice[] =
 "users may be able to read your cached credentials. Consider running:\n"
 "\n"
 "      chmod 0700 %s";
-static void check_socket_directory(const char *path)
+static void init_socket_directory(const char *path)
 {
        struct stat st;
        char *path_copy = xstrdup(path);
@@ -224,20 +224,27 @@ static void check_socket_directory(const char *path)
        if (!stat(dir, &st)) {
                if (st.st_mode & 077)
                        die(permissions_advice, dir);
-               free(path_copy);
-               return;
+       } else {
+               /*
+                * We must be sure to create the directory with the correct mode,
+                * not just chmod it after the fact; otherwise, there is a race
+                * condition in which somebody can chdir to it, sleep, then try to open
+                * our protected socket.
+                */
+               if (safe_create_leading_directories_const(dir) < 0)
+                       die_errno("unable to create directories for '%s'", dir);
+               if (mkdir(dir, 0700) < 0)
+                       die_errno("unable to mkdir '%s'", dir);
        }
 
-       /*
-        * We must be sure to create the directory with the correct mode,
-        * not just chmod it after the fact; otherwise, there is a race
-        * condition in which somebody can chdir to it, sleep, then try to open
-        * our protected socket.
-        */
-       if (safe_create_leading_directories_const(dir) < 0)
-               die_errno("unable to create directories for '%s'", dir);
-       if (mkdir(dir, 0700) < 0)
-               die_errno("unable to mkdir '%s'", dir);
+       if (chdir(dir))
+               /*
+                * We don't actually care what our cwd is; we chdir here just to
+                * be a friendly daemon and avoid tying up our original cwd.
+                * If this fails, it's OK to just continue without that benefit.
+                */
+               ;
+
        free(path_copy);
 }
 
@@ -264,7 +271,10 @@ int main(int argc, const char **argv)
        if (!socket_path)
                usage_with_options(usage, options);
 
-       check_socket_directory(socket_path);
+       if (!is_absolute_path(socket_path))
+               die("socket directory must be an absolute path");
+
+       init_socket_directory(socket_path);
        register_tempfile(&socket_file, socket_path);
 
        if (ignore_sighup)