[PATCH] Added support for dropping privileges to git-daemon.
Signed-off-by: Tilman Sauerbeck <tilman@code-monkey.de>
---
This one got the changes you proposed.
Not sure whether the documentation is good enough, I'm not that good at
writing tech docs in english :(
Documentation/git-daemon.txt | 18 ++++++++++++++++
daemon.c | 46 ++++++++++++++++++++++++++++++++++++++----
2 files changed, 59 insertions(+), 5 deletions(-)
diff --git a/Documentation/git-daemon.txt b/Documentation/git-daemon.txt
index 0f7d274..b591895 100644
--- a/Documentation/git-daemon.txt
+++ b/Documentation/git-daemon.txt
@@ -11,7 +11,8 @@ SYNOPSIS
'git-daemon' [--verbose] [--syslog] [--inetd | --port=n] [--export-all]
[--timeout=n] [--init-timeout=n] [--strict-paths]
[--base-path=path] [--user-path | --user-path=path]
- [--reuseaddr] [--detach] [--pid-file=file] [directory...]
+ [--reuseaddr] [--detach] [--pid-file=file]
+ [--user=user [--group=group]] [directory...]
DESCRIPTION
-----------
@@ -93,6 +94,21 @@ OPTIONS
--pid-file=file::
Save the process id in 'file'.
+--user=user::
+--group=group::
+ These two options may be used to make `git-daemon` change its uid and
+ gid before entering the server loop.
+ The uid that's used is the one of 'user'. If `group` is specified,
+ the gid is set to the one of 'group', otherwise, the default gid
+ of 'user' is used.
+
+ Both `group` and `user` need to be passed as the name of the resp of
+ the group, ie you'll get unexpected results if you pass an uid/a gid.
+
+ Note that you probably don't want to use these options if you run
+ git-daemon in inetd mode, since inetd can do the privilege dropping
+ for you.
+
<directory>::
A directory to add to the whitelist of allowed directories. Unless
--strict-paths is specified this will also include subdirectories
diff --git a/daemon.c b/daemon.c
index 012936f..4e94210 100644
--- a/daemon.c
+++ b/daemon.c
@@ -7,6 +7,8 @@ #include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <syslog.h>
+#include <pwd.h>
+#include <grp.h>
#include "pkt-line.h"
#include "cache.h"
#include "exec_cmd.h"
@@ -19,7 +21,8 @@ static const char daemon_usage[] =
"git-daemon [--verbose] [--syslog] [--inetd | --port=n] [--export-all]\n"
" [--timeout=n] [--init-timeout=n] [--strict-paths]\n"
" [--base-path=path] [--user-path | --user-path=path]\n"
-" [--reuseaddr] [--detach] [--pid-file=file] [directory...]";
+" [--reuseaddr] [--detach] [--pid-file=file]\n"
+" [--user=user [[--group=group]] [directory...]";
/* List of acceptable pathname prefixes */
static char **ok_paths;
@@ -701,7 +704,7 @@ static void store_pid(const char *path)
fclose(f);
}
-static int serve(int port)
+static int serve(int port, struct passwd *pass, gid_t gid)
{
int socknum, *socklist;
@@ -709,6 +712,11 @@ static int serve(int port)
if (socknum == 0)
die("unable to allocate any listen sockets on port %u", port);
+ if (pass && gid &&
+ (initgroups(pass->pw_name, gid) || setgid (gid) ||
+ setuid(pass->pw_uid)))
+ die("cannot drop privileges");
+
return service_loop(socknum, socklist);
}
@@ -716,8 +724,11 @@ int main(int argc, char **argv)
{
int port = DEFAULT_GIT_PORT;
int inetd_mode = 0;
- const char *pid_file = NULL;
+ const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
int detach = 0;
+ struct passwd *pass = NULL;
+ struct group *group;
+ gid_t gid = 0;
int i;
/* Without this we cannot rely on waitpid() to tell
@@ -791,6 +802,14 @@ int main(int argc, char **argv)
log_syslog = 1;
continue;
}
+ if (!strncmp(arg, "--user=", 7)) {
+ user_name = arg + 7;
+ continue;
+ }
+ if (!strncmp(arg, "--group=", 8)) {
+ group_name = arg + 8;
+ continue;
+ }
if (!strcmp(arg, "--")) {
ok_paths = &argv[i+1];
break;
@@ -802,6 +821,25 @@ int main(int argc, char **argv)
usage(daemon_usage);
}
+ if (group_name && !user_name)
+ die("--group supplied without --user");
+
+ if (user_name) {
+ pass = getpwnam(user_name);
+ if (!pass)
+ die("user not found - %s", user_name);
+
+ if (!group_name)
+ gid = pass->pw_gid;
+ else {
+ group = getgrnam(group_name);
+ if (!group)
+ die("group not found - %s", group_name);
+
+ gid = group->gr_gid;
+ }
+ }
+
if (log_syslog) {
openlog("git-daemon", 0, LOG_DAEMON);
set_die_routine(daemon_die);
@@ -831,5 +869,5 @@ int main(int argc, char **argv)
if (pid_file)
store_pid(pid_file);
- return serve(port);
+ return serve(port, pass, gid);
}
--
1.4.2