git-daemon support for user-relative paths.

Dropped a fair amount of reundant code in favour of the library code
in path.c

Added option --strict-paths with documentation, with backwards
compatibility for whitelist entries with symlinks.

Everything that worked earlier still works insofar as I have
remembered testing it.

Signed-off-by: Andreas Ericsson <ae@op5.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/Documentation/git-daemon.txt b/Documentation/git-daemon.txt
index 3783858..972e0e1 100644 (file)
--- a/Documentation/git-daemon.txt
+++ b/Documentation/git-daemon.txt
@@ -29,9 +29,15 @@ This is ideally suited for read-only updates, ie pulling from git repositories.
 
 OPTIONS
 -------
++--strict-paths::
+       Match paths exactly (i.e. don't allow "/foo/repo" when the real path is
+       "/foo/repo.git" or "/foo/repo/.git") and don't do user-relative paths.
+       git-daemon will refuse to start when this option is enabled and no
+       whitelist is specified.
+
 --export-all::
        Allow pulling from all directories that look like GIT repositories
-       (have the 'objects' subdirectory and a 'HEAD' file), even if they
+       (have the 'objects' and 'refs' subdirectories), even if they
        do not have the 'git-daemon-export-ok' file.
 
 --inetd::
@@ -57,9 +63,15 @@ OPTIONS
 --verbose::
        Log details about the incoming connections and requested files.
 
+<directory>::
+       A directory to add to the whitelist of allowed directories. Unless
+       --strict-paths is specified this will also include subdirectories
+       of each named directory.
+
 Author
 ------
-Written by Linus Torvalds <torvalds@osdl.org> and YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
+Written by Linus Torvalds <torvalds@osdl.org>, YOSHIFUJI Hideaki
+<yoshfuji@linux-ipv6.org> and the git-list <git@vger.kernel.org>
 
 Documentation
 --------------

diff --git a/Documentation/pull-fetch-param.txt b/Documentation/pull-fetch-param.txt
index a7628aa..6413d52 100644 (file)
--- a/Documentation/pull-fetch-param.txt
+++ b/Documentation/pull-fetch-param.txt
@@ -9,15 +9,16 @@
 - http://host.xz/path/to/repo.git/
 - https://host.xz/path/to/repo.git/
 - git://host.xz/path/to/repo.git/
+- git://host.xz/~user/path/to/repo.git/
 - ssh://host.xz/path/to/repo.git/
 - ssh://host.xz/~user/path/to/repo.git/
 - ssh://host.xz/~/path/to/repo.git
 ===============================================================
 +
        SSH Is the default transport protocol and also supports an
-       scp-like syntax.  Both syntaxes support username expansion.
-       The following three are identical to the last three above,
-       respectively:
+       scp-like syntax.  Both syntaxes support username expansion,
+       as does the native git protocol. The following three are
+       identical to the last three above, respectively:
 +
 ===============================================================
 - host.xz:/path/to/repo.git/

diff --git a/daemon.c b/daemon.c
index 2b81152..ac4c94b 100644 (file)
--- a/daemon.c
+++ b/daemon.c
@@ -15,10 +15,11 @@ static int verbose;
 
 static const char daemon_usage[] =
 "git-daemon [--verbose] [--syslog] [--inetd | --port=n] [--export-all]\n"
-"           [--timeout=n] [--init-timeout=n] [directory...]";
+"           [--timeout=n] [--init-timeout=n] [--strict-paths] [directory...]";
 
 /* List of acceptable pathname prefixes */
 static char **ok_paths = NULL;
+static int strict_paths = 0;
 
 /* If this is set, git-daemon-export-ok is not required */
 static int export_all_trees = 0;
@@ -81,69 +82,56 @@ static void loginfo(const char *err, ...)
        va_end(params);
 }
 
-static int path_ok(const char *dir)
+static char *path_ok(char *dir)
 {
-       const char *p = dir;
-       char **pp;
-       int sl, ndot;
+       char *path = enter_repo(dir, strict_paths);
 
-       /* The pathname here should be an absolute path. */
-       if ( *p++ != '/' )
-               return 0;
-
-       sl = 1;  ndot = 0;
-
-       for (;;) {
-               if ( *p == '.' ) {
-                       ndot++;
-               } else if ( *p == '\0' ) {
-                       /* Reject "." and ".." at the end of the path */
-                       if ( sl && ndot > 0 && ndot < 3 )
-                               return 0;
-
-                       /* Otherwise OK */
-                       break;
-               } else if ( *p == '/' ) {
-                       /* Refuse "", "." or ".." */
-                       if ( sl && ndot < 3 )
-                               return 0;
-                       sl = 1;
-                       ndot = 0;
-               } else {
-                       sl = ndot = 0;
-               }
-               p++;
+       if (!path) {
+               logerror("'%s': unable to chdir or not a git archive", dir);
+               return NULL;
        }
 
        if ( ok_paths && *ok_paths ) {
-               int ok = 0;
+               char **pp = NULL;
                int dirlen = strlen(dir);
+               int pathlen = strlen(path);
 
                for ( pp = ok_paths ; *pp ; pp++ ) {
                        int len = strlen(*pp);
-                       if ( len <= dirlen &&
-                            !strncmp(*pp, dir, len) &&
-                            (dir[len] == '/' || dir[len] == '\0') ) {
-                               ok = 1;
-                               break;
+                       /* because of symlinks we must match both what the
+                        * user passed and the canonicalized path, otherwise
+                        * the user can send a string matching either a whitelist
+                        * entry or an actual directory exactly and still not
+                        * get through */
+                       if (len <= pathlen && !memcmp(*pp, path, len)) {
+                               if (path[len] == '\0' || (!strict_paths && path[len] == '/'))
+                                       return path;
+                       }
+                       if (len <= dirlen && !memcmp(*pp, dir, len)) {
+                               if (dir[len] == '\0' || (!strict_paths && dir[len] == '/'))
+                                       return path;
                        }
                }
-
-               if ( !ok )
-                       return 0; /* Path not in whitelist */
+       }
+       else {
+               /* be backwards compatible */
+               if (!strict_paths)
+                       return path;
        }
 
-       return 1;               /* Path acceptable */
+       logerror("'%s': not in whitelist", path);
+       return NULL;            /* Fallthrough. Deny by default */
 }
 
-static int set_dir(const char *dir)
+static int upload(char *dir)
 {
-       if (!path_ok(dir)) {
-               errno = EACCES;
-               return -1;
-       }
+       /* Timeout as string */
+       char timeout_buf[64];
+       const char *path;
+
+       loginfo("Request for '%s'", dir);
 
-       if ( chdir(dir) )
+       if (!(path = path_ok(dir)))
                return -1;
 
        /*
@@ -152,45 +140,17 @@ static int set_dir(const char *dir)
         * We want a readable HEAD, usable "objects" directory, and
         * a "git-daemon-export-ok" flag that says that the other side
         * is ok with us doing this.
+        *
+        * path_ok() uses enter_repo() and does whitelist checking.
+        * We only need to make sure the repository is exported.
         */
+
        if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
+               logerror("'%s': repository not exported.", path);
                errno = EACCES;
                return -1;
        }
 
-       if (access("objects/", X_OK) || access("HEAD", R_OK)) {
-               errno = EINVAL;
-               return -1;
-       }
-
-       /* If all this passed, we're OK */
-       return 0;
-}
-
-static int upload(char *dir)
-{
-       /* Try paths in this order */
-       static const char *paths[] = { "%s", "%s/.git", "%s.git", "%s.git/.git", NULL };
-       const char **pp;
-       /* Enough for the longest path above including final null */
-       int buflen = strlen(dir)+10;
-       char *dirbuf = xmalloc(buflen);
-       /* Timeout as string */
-       char timeout_buf[64];
-
-       loginfo("Request for '%s'", dir);
-
-       for ( pp = paths ; *pp ; pp++ ) {
-               snprintf(dirbuf, buflen, *pp, dir);
-               if ( !set_dir(dirbuf) )
-                       break;
-       }
-
-       if ( !*pp ) {
-               logerror("Cannot set directory '%s': %s", dir, strerror(errno));
-               return -1;
-       }
-
        /*
         * We'll ignore SIGTERM from now on, we have a
         * good client.
@@ -200,7 +160,7 @@ static int upload(char *dir)
        snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
 
        /* git-upload-pack only ever reads stuff, so this is safe */
-       execlp("git-upload-pack", "git-upload-pack", "--strict", timeout_buf, ".", NULL);
+       execlp("git-upload-pack", "git-upload-pack", "--strict", timeout_buf, path, NULL);
        return -1;
 }
 
@@ -216,7 +176,7 @@ static int execute(void)
        if (len && line[len-1] == '\n')
                line[--len] = 0;
 
-       if (!strncmp("git-upload-pack /", line, 17))
+       if (!strncmp("git-upload-pack ", line, 16))
                return upload(line+16);
 
        logerror("Protocol error: '%s'", line);
@@ -617,6 +577,10 @@ int main(int argc, char **argv)
                        init_timeout = atoi(arg+15);
                        continue;
                }
+               if (!strcmp(arg, "--strict-paths")) {
+                       strict_paths = 1;
+                       continue;
+               }
                if (!strcmp(arg, "--")) {
                        ok_paths = &argv[i+1];
                        break;
@@ -631,6 +595,14 @@ int main(int argc, char **argv)
        if (log_syslog)
                openlog("git-daemon", 0, LOG_DAEMON);
 
+       if (strict_paths && (!ok_paths || !*ok_paths)) {
+               if (!inetd_mode)
+                       die("git-daemon: option --strict-paths requires a whitelist");
+
+               logerror("option --strict-paths requires a whitelist");
+               exit (1);
+       }
+
        if (inetd_mode) {
                fclose(stderr); //FIXME: workaround
                return execute();