Merge branch 'ts/daemon'

* ts/daemon:
Added support for dropping privileges to git-daemon.

diff --combined daemon.c
index 5bf5c82627beb8d8a5af71bce55c7e850ea54c46,dd3915a07ab63621a55f7c9404659c1039d336cd..66ec830b7cab775e16c3fe06539e698edd6b7aff
--- 1/daemon.c
--- 2/daemon.c
+++ b/daemon.c
@@@ -7,6 -7,8 +7,8 @@@
  #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 +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;
@@@ -526,6 -529,7 +529,6 @@@ static int socksetup(int port, int **so
  
        for (ai = ai0; ai; ai = ai->ai_next) {
                int sockfd;
 -              int *newlist;
  
                sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
                if (sockfd < 0)
@@@ -559,7 -563,11 +562,7 @@@
                        continue;       /* not fatal */
                }
  
 -              newlist = realloc(socklist, sizeof(int) * (socknum + 1));
 -              if (!newlist)
 -                      die("memory allocation failed: %s", strerror(errno));
 -
 -              socklist = newlist;
 +              socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
                socklist[socknum++] = sockfd;
  
                if (maxfd < sockfd)
@@@ -696,7 -704,7 +699,7 @@@ 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;
  
@@@ -704,6 -712,11 +707,11 @@@
        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);
  }
  
@@@ -711,8 -724,11 +719,11 @@@ 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
@@@ -786,6 -802,14 +797,14 @@@
                        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;
@@@ -797,6 -821,28 +816,28 @@@
                usage(daemon_usage);
        }
  
+       if (inetd_mode && (group_name || user_name))
+               die("--user and --group are incompatible with --inetd");
+ 
+       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);
@@@ -826,5 -872,5 +867,5 @@@
        if (pid_file)
                store_pid(pid_file);
  
-       return serve(port);
+       return serve(port, pass, gid);
  }