[PATCH] Added support for dropping privileges to git-daemon.
Signed-off-by: Tilman Sauerbeck <tilman@code-monkey.de>
---
My idea was to keep the code simple :)
Anyway, this patch has the code you proposed.
Documentation/git-daemon.txt | 11 +++++++++-
daemon.c | 45 +++++++++++++++++++++++++++++++++++++++++-
2 files changed, 54 insertions(+), 2 deletions(-)
diff --git a/Documentation/git-daemon.txt b/Documentation/git-daemon.txt
index 0f7d274..3c1bc85 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=u [--group=g]] [directory...]
DESCRIPTION
-----------
@@ -93,6 +94,14 @@ OPTIONS
--pid-file=file::
Save the process id in 'file'.
+--user=u::
+--group=g::
+ 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 'u'. If `group` is specified,
+ the gid is set to the one of 'g', otherwise, the default gid
+ of 'u' is used.
+
<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..70be10f 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"
@@ -14,12 +16,15 @@ #include "exec_cmd.h"
static int log_syslog;
static int verbose;
static int reuseaddr;
+static const char *user;
+static const char *group;
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=u] [--group=g] [directory...]";
/* List of acceptable pathname prefixes */
static char **ok_paths;
@@ -701,6 +706,30 @@ static void store_pid(const char *path)
fclose(f);
}
+static void drop_privileges()
+{
+ struct passwd *p;
+ struct group *g;
+ gid_t gid;
+
+ p = getpwnam (user);
+ if (!p)
+ die("user not found - %s", user);
+
+ if (!group)
+ gid = p->pw_gid;
+ else {
+ g = getgrnam (group);
+ if (!g)
+ die("group not found - %s", group);
+
+ gid = g->gr_gid;
+ }
+
+ if (initgroups (p->pw_name, gid) || setgid (gid) || setuid (p->pw_uid))
+ die("cannot drop privileges");
+}
+
static int serve(int port)
{
int socknum, *socklist;
@@ -709,6 +738,9 @@ static int serve(int port)
if (socknum == 0)
die("unable to allocate any listen sockets on port %u", port);
+ if (user)
+ drop_privileges();
+
return service_loop(socknum, socklist);
}
@@ -791,6 +823,14 @@ int main(int argc, char **argv)
log_syslog = 1;
continue;
}
+ if (!strncmp(arg, "--user=", 7)) {
+ user = arg + 7;
+ continue;
+ }
+ if (!strncmp(arg, "--group=", 8)) {
+ group = arg + 8;
+ continue;
+ }
if (!strcmp(arg, "--")) {
ok_paths = &argv[i+1];
break;
@@ -802,6 +842,9 @@ int main(int argc, char **argv)
usage(daemon_usage);
}
+ if (group && !user)
+ die("--group supplied without --user");
+
if (log_syslog) {
openlog("git-daemon", 0, LOG_DAEMON);
set_die_routine(daemon_die);
--
1.4.2