Add "-h/-H" parsing to "git grep"
[git] / daemon.c
1 #include <signal.h>
2 #include <sys/wait.h>
3 #include <sys/socket.h>
4 #include <sys/time.h>
5 #include <sys/poll.h>
6 #include <netdb.h>
7 #include <netinet/in.h>
8 #include <arpa/inet.h>
9 #include <syslog.h>
10 #include <pwd.h>
11 #include <grp.h>
12 #include "pkt-line.h"
13 #include "cache.h"
14 #include "exec_cmd.h"
15
16 static int log_syslog;
17 static int verbose;
18 static int reuseaddr;
19
20 static const char daemon_usage[] =
21 "git-daemon [--verbose] [--syslog] [--inetd | --port=n] [--export-all]\n"
22 "           [--timeout=n] [--init-timeout=n] [--strict-paths]\n"
23 "           [--base-path=path] [--user-path | --user-path=path]\n"
24 "           [--reuseaddr] [--detach] [--pid-file=file]\n"
25 "           [--[enable|disable|allow-override|forbid-override]=service]\n"
26 "           [--user=user [[--group=group]] [directory...]";
27
28 /* List of acceptable pathname prefixes */
29 static char **ok_paths;
30 static int strict_paths;
31
32 /* If this is set, git-daemon-export-ok is not required */
33 static int export_all_trees;
34
35 /* Take all paths relative to this one if non-NULL */
36 static char *base_path;
37
38 /* If defined, ~user notation is allowed and the string is inserted
39  * after ~user/.  E.g. a request to git://host/~alice/frotz would
40  * go to /home/alice/pub_git/frotz with --user-path=pub_git.
41  */
42 static const char *user_path;
43
44 /* Timeout, and initial timeout */
45 static unsigned int timeout;
46 static unsigned int init_timeout;
47
48 static void logreport(int priority, const char *err, va_list params)
49 {
50         /* We should do a single write so that it is atomic and output
51          * of several processes do not get intermingled. */
52         char buf[1024];
53         int buflen;
54         int maxlen, msglen;
55
56         /* sizeof(buf) should be big enough for "[pid] \n" */
57         buflen = snprintf(buf, sizeof(buf), "[%ld] ", (long) getpid());
58
59         maxlen = sizeof(buf) - buflen - 1; /* -1 for our own LF */
60         msglen = vsnprintf(buf + buflen, maxlen, err, params);
61
62         if (log_syslog) {
63                 syslog(priority, "%s", buf);
64                 return;
65         }
66
67         /* maxlen counted our own LF but also counts space given to
68          * vsnprintf for the terminating NUL.  We want to make sure that
69          * we have space for our own LF and NUL after the "meat" of the
70          * message, so truncate it at maxlen - 1.
71          */
72         if (msglen > maxlen - 1)
73                 msglen = maxlen - 1;
74         else if (msglen < 0)
75                 msglen = 0; /* Protect against weird return values. */
76         buflen += msglen;
77
78         buf[buflen++] = '\n';
79         buf[buflen] = '\0';
80
81         write(2, buf, buflen);
82 }
83
84 static void logerror(const char *err, ...)
85 {
86         va_list params;
87         va_start(params, err);
88         logreport(LOG_ERR, err, params);
89         va_end(params);
90 }
91
92 static void loginfo(const char *err, ...)
93 {
94         va_list params;
95         if (!verbose)
96                 return;
97         va_start(params, err);
98         logreport(LOG_INFO, err, params);
99         va_end(params);
100 }
101
102 static void NORETURN daemon_die(const char *err, va_list params)
103 {
104         logreport(LOG_ERR, err, params);
105         exit(1);
106 }
107
108 static int avoid_alias(char *p)
109 {
110         int sl, ndot;
111
112         /* 
113          * This resurrects the belts and suspenders paranoia check by HPA
114          * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
115          * does not do getcwd() based path canonicalizations.
116          *
117          * sl becomes true immediately after seeing '/' and continues to
118          * be true as long as dots continue after that without intervening
119          * non-dot character.
120          */
121         if (!p || (*p != '/' && *p != '~'))
122                 return -1;
123         sl = 1; ndot = 0;
124         p++;
125
126         while (1) {
127                 char ch = *p++;
128                 if (sl) {
129                         if (ch == '.')
130                                 ndot++;
131                         else if (ch == '/') {
132                                 if (ndot < 3)
133                                         /* reject //, /./ and /../ */
134                                         return -1;
135                                 ndot = 0;
136                         }
137                         else if (ch == 0) {
138                                 if (0 < ndot && ndot < 3)
139                                         /* reject /.$ and /..$ */
140                                         return -1;
141                                 return 0;
142                         }
143                         else
144                                 sl = ndot = 0;
145                 }
146                 else if (ch == 0)
147                         return 0;
148                 else if (ch == '/') {
149                         sl = 1;
150                         ndot = 0;
151                 }
152         }
153 }
154
155 static char *path_ok(char *dir)
156 {
157         static char rpath[PATH_MAX];
158         char *path;
159
160         if (avoid_alias(dir)) {
161                 logerror("'%s': aliased", dir);
162                 return NULL;
163         }
164
165         if (*dir == '~') {
166                 if (!user_path) {
167                         logerror("'%s': User-path not allowed", dir);
168                         return NULL;
169                 }
170                 if (*user_path) {
171                         /* Got either "~alice" or "~alice/foo";
172                          * rewrite them to "~alice/%s" or
173                          * "~alice/%s/foo".
174                          */
175                         int namlen, restlen = strlen(dir);
176                         char *slash = strchr(dir, '/');
177                         if (!slash)
178                                 slash = dir + restlen;
179                         namlen = slash - dir;
180                         restlen -= namlen;
181                         loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
182                         snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
183                                  namlen, dir, user_path, restlen, slash);
184                         dir = rpath;
185                 }
186         }
187         else if (base_path) {
188                 if (*dir != '/') {
189                         /* Allow only absolute */
190                         logerror("'%s': Non-absolute path denied (base-path active)", dir);
191                         return NULL;
192                 }
193                 else {
194                         snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
195                         dir = rpath;
196                 }
197         }
198
199         path = enter_repo(dir, strict_paths);
200
201         if (!path) {
202                 logerror("'%s': unable to chdir or not a git archive", dir);
203                 return NULL;
204         }
205
206         if ( ok_paths && *ok_paths ) {
207                 char **pp;
208                 int pathlen = strlen(path);
209
210                 /* The validation is done on the paths after enter_repo
211                  * appends optional {.git,.git/.git} and friends, but 
212                  * it does not use getcwd().  So if your /pub is
213                  * a symlink to /mnt/pub, you can whitelist /pub and
214                  * do not have to say /mnt/pub.
215                  * Do not say /pub/.
216                  */
217                 for ( pp = ok_paths ; *pp ; pp++ ) {
218                         int len = strlen(*pp);
219                         if (len <= pathlen &&
220                             !memcmp(*pp, path, len) &&
221                             (path[len] == '\0' ||
222                              (!strict_paths && path[len] == '/')))
223                                 return path;
224                 }
225         }
226         else {
227                 /* be backwards compatible */
228                 if (!strict_paths)
229                         return path;
230         }
231
232         logerror("'%s': not in whitelist", path);
233         return NULL;            /* Fallthrough. Deny by default */
234 }
235
236 typedef int (*daemon_service_fn)(void);
237 struct daemon_service {
238         const char *name;
239         const char *config_name;
240         daemon_service_fn fn;
241         int enabled;
242         int overridable;
243 };
244
245 static struct daemon_service *service_looking_at;
246 static int service_enabled;
247
248 static int git_daemon_config(const char *var, const char *value)
249 {
250         if (!strncmp(var, "daemon.", 7) &&
251             !strcmp(var + 7, service_looking_at->config_name)) {
252                 service_enabled = git_config_bool(var, value);
253                 return 0;
254         }
255
256         /* we are not interested in parsing any other configuration here */
257         return 0;
258 }
259
260 static int run_service(char *dir, struct daemon_service *service)
261 {
262         const char *path;
263         int enabled = service->enabled;
264
265         loginfo("Request %s for '%s'", service->name, dir);
266
267         if (!enabled && !service->overridable) {
268                 logerror("'%s': service not enabled.", service->name);
269                 errno = EACCES;
270                 return -1;
271         }
272
273         if (!(path = path_ok(dir)))
274                 return -1;
275
276         /*
277          * Security on the cheap.
278          *
279          * We want a readable HEAD, usable "objects" directory, and
280          * a "git-daemon-export-ok" flag that says that the other side
281          * is ok with us doing this.
282          *
283          * path_ok() uses enter_repo() and does whitelist checking.
284          * We only need to make sure the repository is exported.
285          */
286
287         if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
288                 logerror("'%s': repository not exported.", path);
289                 errno = EACCES;
290                 return -1;
291         }
292
293         if (service->overridable) {
294                 service_looking_at = service;
295                 service_enabled = -1;
296                 git_config(git_daemon_config);
297                 if (0 <= service_enabled)
298                         enabled = service_enabled;
299         }
300         if (!enabled) {
301                 logerror("'%s': service not enabled for '%s'",
302                          service->name, path);
303                 errno = EACCES;
304                 return -1;
305         }
306
307         /*
308          * We'll ignore SIGTERM from now on, we have a
309          * good client.
310          */
311         signal(SIGTERM, SIG_IGN);
312
313         return service->fn();
314 }
315
316 static int upload_pack(void)
317 {
318         /* Timeout as string */
319         char timeout_buf[64];
320
321         snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
322
323         /* git-upload-pack only ever reads stuff, so this is safe */
324         execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL);
325         return -1;
326 }
327
328 static struct daemon_service daemon_service[] = {
329         { "upload-pack", "uploadpack", upload_pack, 1, 1 },
330 };
331
332 static void enable_service(const char *name, int ena) {
333         int i;
334         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
335                 if (!strcmp(daemon_service[i].name, name)) {
336                         daemon_service[i].enabled = ena;
337                         return;
338                 }
339         }
340         die("No such service %s", name);
341 }
342
343 static void make_service_overridable(const char *name, int ena) {
344         int i;
345         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
346                 if (!strcmp(daemon_service[i].name, name)) {
347                         daemon_service[i].overridable = ena;
348                         return;
349                 }
350         }
351         die("No such service %s", name);
352 }
353
354 static int execute(struct sockaddr *addr)
355 {
356         static char line[1000];
357         int pktlen, len, i;
358
359         if (addr) {
360                 char addrbuf[256] = "";
361                 int port = -1;
362
363                 if (addr->sa_family == AF_INET) {
364                         struct sockaddr_in *sin_addr = (void *) addr;
365                         inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
366                         port = sin_addr->sin_port;
367 #ifndef NO_IPV6
368                 } else if (addr && addr->sa_family == AF_INET6) {
369                         struct sockaddr_in6 *sin6_addr = (void *) addr;
370
371                         char *buf = addrbuf;
372                         *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
373                         inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
374                         strcat(buf, "]");
375
376                         port = sin6_addr->sin6_port;
377 #endif
378                 }
379                 loginfo("Connection from %s:%d", addrbuf, port);
380         }
381
382         alarm(init_timeout ? init_timeout : timeout);
383         pktlen = packet_read_line(0, line, sizeof(line));
384         alarm(0);
385
386         len = strlen(line);
387         if (pktlen != len)
388                 loginfo("Extended attributes (%d bytes) exist <%.*s>",
389                         (int) pktlen - len,
390                         (int) pktlen - len, line + len + 1);
391         if (len && line[len-1] == '\n')
392                 line[--len] = 0;
393
394         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
395                 struct daemon_service *s = &(daemon_service[i]);
396                 int namelen = strlen(s->name);
397                 if (!strncmp("git-", line, 4) &&
398                     !strncmp(s->name, line + 4, namelen) &&
399                     line[namelen + 4] == ' ')
400                         return run_service(line + namelen + 5, s);
401         }
402
403         logerror("Protocol error: '%s'", line);
404         return -1;
405 }
406
407
408 /*
409  * We count spawned/reaped separately, just to avoid any
410  * races when updating them from signals. The SIGCHLD handler
411  * will only update children_reaped, and the fork logic will
412  * only update children_spawned.
413  *
414  * MAX_CHILDREN should be a power-of-two to make the modulus
415  * operation cheap. It should also be at least twice
416  * the maximum number of connections we will ever allow.
417  */
418 #define MAX_CHILDREN 128
419
420 static int max_connections = 25;
421
422 /* These are updated by the signal handler */
423 static volatile unsigned int children_reaped;
424 static pid_t dead_child[MAX_CHILDREN];
425
426 /* These are updated by the main loop */
427 static unsigned int children_spawned;
428 static unsigned int children_deleted;
429
430 static struct child {
431         pid_t pid;
432         int addrlen;
433         struct sockaddr_storage address;
434 } live_child[MAX_CHILDREN];
435
436 static void add_child(int idx, pid_t pid, struct sockaddr *addr, int addrlen)
437 {
438         live_child[idx].pid = pid;
439         live_child[idx].addrlen = addrlen;
440         memcpy(&live_child[idx].address, addr, addrlen);
441 }
442
443 /*
444  * Walk from "deleted" to "spawned", and remove child "pid".
445  *
446  * We move everything up by one, since the new "deleted" will
447  * be one higher.
448  */
449 static void remove_child(pid_t pid, unsigned deleted, unsigned spawned)
450 {
451         struct child n;
452
453         deleted %= MAX_CHILDREN;
454         spawned %= MAX_CHILDREN;
455         if (live_child[deleted].pid == pid) {
456                 live_child[deleted].pid = -1;
457                 return;
458         }
459         n = live_child[deleted];
460         for (;;) {
461                 struct child m;
462                 deleted = (deleted + 1) % MAX_CHILDREN;
463                 if (deleted == spawned)
464                         die("could not find dead child %d\n", pid);
465                 m = live_child[deleted];
466                 live_child[deleted] = n;
467                 if (m.pid == pid)
468                         return;
469                 n = m;
470         }
471 }
472
473 /*
474  * This gets called if the number of connections grows
475  * past "max_connections".
476  *
477  * We _should_ start off by searching for connections
478  * from the same IP, and if there is some address wth
479  * multiple connections, we should kill that first.
480  *
481  * As it is, we just "randomly" kill 25% of the connections,
482  * and our pseudo-random generator sucks too. I have no
483  * shame.
484  *
485  * Really, this is just a place-holder for a _real_ algorithm.
486  */
487 static void kill_some_children(int signo, unsigned start, unsigned stop)
488 {
489         start %= MAX_CHILDREN;
490         stop %= MAX_CHILDREN;
491         while (start != stop) {
492                 if (!(start & 3))
493                         kill(live_child[start].pid, signo);
494                 start = (start + 1) % MAX_CHILDREN;
495         }
496 }
497
498 static void check_max_connections(void)
499 {
500         for (;;) {
501                 int active;
502                 unsigned spawned, reaped, deleted;
503
504                 spawned = children_spawned;
505                 reaped = children_reaped;
506                 deleted = children_deleted;
507
508                 while (deleted < reaped) {
509                         pid_t pid = dead_child[deleted % MAX_CHILDREN];
510                         remove_child(pid, deleted, spawned);
511                         deleted++;
512                 }
513                 children_deleted = deleted;
514
515                 active = spawned - deleted;
516                 if (active <= max_connections)
517                         break;
518
519                 /* Kill some unstarted connections with SIGTERM */
520                 kill_some_children(SIGTERM, deleted, spawned);
521                 if (active <= max_connections << 1)
522                         break;
523
524                 /* If the SIGTERM thing isn't helping use SIGKILL */
525                 kill_some_children(SIGKILL, deleted, spawned);
526                 sleep(1);
527         }
528 }
529
530 static void handle(int incoming, struct sockaddr *addr, int addrlen)
531 {
532         pid_t pid = fork();
533
534         if (pid) {
535                 unsigned idx;
536
537                 close(incoming);
538                 if (pid < 0)
539                         return;
540
541                 idx = children_spawned % MAX_CHILDREN;
542                 children_spawned++;
543                 add_child(idx, pid, addr, addrlen);
544
545                 check_max_connections();
546                 return;
547         }
548
549         dup2(incoming, 0);
550         dup2(incoming, 1);
551         close(incoming);
552
553         exit(execute(addr));
554 }
555
556 static void child_handler(int signo)
557 {
558         for (;;) {
559                 int status;
560                 pid_t pid = waitpid(-1, &status, WNOHANG);
561
562                 if (pid > 0) {
563                         unsigned reaped = children_reaped;
564                         dead_child[reaped % MAX_CHILDREN] = pid;
565                         children_reaped = reaped + 1;
566                         /* XXX: Custom logging, since we don't wanna getpid() */
567                         if (verbose) {
568                                 const char *dead = "";
569                                 if (!WIFEXITED(status) || WEXITSTATUS(status) > 0)
570                                         dead = " (with error)";
571                                 if (log_syslog)
572                                         syslog(LOG_INFO, "[%d] Disconnected%s", pid, dead);
573                                 else
574                                         fprintf(stderr, "[%d] Disconnected%s\n", pid, dead);
575                         }
576                         continue;
577                 }
578                 break;
579         }
580 }
581
582 static int set_reuse_addr(int sockfd)
583 {
584         int on = 1;
585
586         if (!reuseaddr)
587                 return 0;
588         return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
589                           &on, sizeof(on));
590 }
591
592 #ifndef NO_IPV6
593
594 static int socksetup(int port, int **socklist_p)
595 {
596         int socknum = 0, *socklist = NULL;
597         int maxfd = -1;
598         char pbuf[NI_MAXSERV];
599
600         struct addrinfo hints, *ai0, *ai;
601         int gai;
602
603         sprintf(pbuf, "%d", port);
604         memset(&hints, 0, sizeof(hints));
605         hints.ai_family = AF_UNSPEC;
606         hints.ai_socktype = SOCK_STREAM;
607         hints.ai_protocol = IPPROTO_TCP;
608         hints.ai_flags = AI_PASSIVE;
609
610         gai = getaddrinfo(NULL, pbuf, &hints, &ai0);
611         if (gai)
612                 die("getaddrinfo() failed: %s\n", gai_strerror(gai));
613
614         for (ai = ai0; ai; ai = ai->ai_next) {
615                 int sockfd;
616
617                 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
618                 if (sockfd < 0)
619                         continue;
620                 if (sockfd >= FD_SETSIZE) {
621                         error("too large socket descriptor.");
622                         close(sockfd);
623                         continue;
624                 }
625
626 #ifdef IPV6_V6ONLY
627                 if (ai->ai_family == AF_INET6) {
628                         int on = 1;
629                         setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
630                                    &on, sizeof(on));
631                         /* Note: error is not fatal */
632                 }
633 #endif
634
635                 if (set_reuse_addr(sockfd)) {
636                         close(sockfd);
637                         continue;
638                 }
639
640                 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
641                         close(sockfd);
642                         continue;       /* not fatal */
643                 }
644                 if (listen(sockfd, 5) < 0) {
645                         close(sockfd);
646                         continue;       /* not fatal */
647                 }
648
649                 socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
650                 socklist[socknum++] = sockfd;
651
652                 if (maxfd < sockfd)
653                         maxfd = sockfd;
654         }
655
656         freeaddrinfo(ai0);
657
658         *socklist_p = socklist;
659         return socknum;
660 }
661
662 #else /* NO_IPV6 */
663
664 static int socksetup(int port, int **socklist_p)
665 {
666         struct sockaddr_in sin;
667         int sockfd;
668
669         sockfd = socket(AF_INET, SOCK_STREAM, 0);
670         if (sockfd < 0)
671                 return 0;
672
673         memset(&sin, 0, sizeof sin);
674         sin.sin_family = AF_INET;
675         sin.sin_addr.s_addr = htonl(INADDR_ANY);
676         sin.sin_port = htons(port);
677
678         if (set_reuse_addr(sockfd)) {
679                 close(sockfd);
680                 return 0;
681         }
682
683         if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
684                 close(sockfd);
685                 return 0;
686         }
687
688         if (listen(sockfd, 5) < 0) {
689                 close(sockfd);
690                 return 0;
691         }
692
693         *socklist_p = xmalloc(sizeof(int));
694         **socklist_p = sockfd;
695         return 1;
696 }
697
698 #endif
699
700 static int service_loop(int socknum, int *socklist)
701 {
702         struct pollfd *pfd;
703         int i;
704
705         pfd = xcalloc(socknum, sizeof(struct pollfd));
706
707         for (i = 0; i < socknum; i++) {
708                 pfd[i].fd = socklist[i];
709                 pfd[i].events = POLLIN;
710         }
711
712         signal(SIGCHLD, child_handler);
713
714         for (;;) {
715                 int i;
716
717                 if (poll(pfd, socknum, -1) < 0) {
718                         if (errno != EINTR) {
719                                 error("poll failed, resuming: %s",
720                                       strerror(errno));
721                                 sleep(1);
722                         }
723                         continue;
724                 }
725
726                 for (i = 0; i < socknum; i++) {
727                         if (pfd[i].revents & POLLIN) {
728                                 struct sockaddr_storage ss;
729                                 unsigned int sslen = sizeof(ss);
730                                 int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
731                                 if (incoming < 0) {
732                                         switch (errno) {
733                                         case EAGAIN:
734                                         case EINTR:
735                                         case ECONNABORTED:
736                                                 continue;
737                                         default:
738                                                 die("accept returned %s", strerror(errno));
739                                         }
740                                 }
741                                 handle(incoming, (struct sockaddr *)&ss, sslen);
742                         }
743                 }
744         }
745 }
746
747 /* if any standard file descriptor is missing open it to /dev/null */
748 static void sanitize_stdfds(void)
749 {
750         int fd = open("/dev/null", O_RDWR, 0);
751         while (fd != -1 && fd < 2)
752                 fd = dup(fd);
753         if (fd == -1)
754                 die("open /dev/null or dup failed: %s", strerror(errno));
755         if (fd > 2)
756                 close(fd);
757 }
758
759 static void daemonize(void)
760 {
761         switch (fork()) {
762                 case 0:
763                         break;
764                 case -1:
765                         die("fork failed: %s", strerror(errno));
766                 default:
767                         exit(0);
768         }
769         if (setsid() == -1)
770                 die("setsid failed: %s", strerror(errno));
771         close(0);
772         close(1);
773         close(2);
774         sanitize_stdfds();
775 }
776
777 static void store_pid(const char *path)
778 {
779         FILE *f = fopen(path, "w");
780         if (!f)
781                 die("cannot open pid file %s: %s", path, strerror(errno));
782         fprintf(f, "%d\n", getpid());
783         fclose(f);
784 }
785
786 static int serve(int port, struct passwd *pass, gid_t gid)
787 {
788         int socknum, *socklist;
789
790         socknum = socksetup(port, &socklist);
791         if (socknum == 0)
792                 die("unable to allocate any listen sockets on port %u", port);
793
794         if (pass && gid &&
795             (initgroups(pass->pw_name, gid) || setgid (gid) ||
796              setuid(pass->pw_uid)))
797                 die("cannot drop privileges");
798
799         return service_loop(socknum, socklist);
800 }
801
802 int main(int argc, char **argv)
803 {
804         int port = DEFAULT_GIT_PORT;
805         int inetd_mode = 0;
806         const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
807         int detach = 0;
808         struct passwd *pass = NULL;
809         struct group *group;
810         gid_t gid = 0;
811         int i;
812
813         /* Without this we cannot rely on waitpid() to tell
814          * what happened to our children.
815          */
816         signal(SIGCHLD, SIG_DFL);
817
818         for (i = 1; i < argc; i++) {
819                 char *arg = argv[i];
820
821                 if (!strncmp(arg, "--port=", 7)) {
822                         char *end;
823                         unsigned long n;
824                         n = strtoul(arg+7, &end, 0);
825                         if (arg[7] && !*end) {
826                                 port = n;
827                                 continue;
828                         }
829                 }
830                 if (!strcmp(arg, "--inetd")) {
831                         inetd_mode = 1;
832                         log_syslog = 1;
833                         continue;
834                 }
835                 if (!strcmp(arg, "--verbose")) {
836                         verbose = 1;
837                         continue;
838                 }
839                 if (!strcmp(arg, "--syslog")) {
840                         log_syslog = 1;
841                         continue;
842                 }
843                 if (!strcmp(arg, "--export-all")) {
844                         export_all_trees = 1;
845                         continue;
846                 }
847                 if (!strncmp(arg, "--timeout=", 10)) {
848                         timeout = atoi(arg+10);
849                         continue;
850                 }
851                 if (!strncmp(arg, "--init-timeout=", 15)) {
852                         init_timeout = atoi(arg+15);
853                         continue;
854                 }
855                 if (!strcmp(arg, "--strict-paths")) {
856                         strict_paths = 1;
857                         continue;
858                 }
859                 if (!strncmp(arg, "--base-path=", 12)) {
860                         base_path = arg+12;
861                         continue;
862                 }
863                 if (!strcmp(arg, "--reuseaddr")) {
864                         reuseaddr = 1;
865                         continue;
866                 }
867                 if (!strcmp(arg, "--user-path")) {
868                         user_path = "";
869                         continue;
870                 }
871                 if (!strncmp(arg, "--user-path=", 12)) {
872                         user_path = arg + 12;
873                         continue;
874                 }
875                 if (!strncmp(arg, "--pid-file=", 11)) {
876                         pid_file = arg + 11;
877                         continue;
878                 }
879                 if (!strcmp(arg, "--detach")) {
880                         detach = 1;
881                         log_syslog = 1;
882                         continue;
883                 }
884                 if (!strncmp(arg, "--user=", 7)) {
885                         user_name = arg + 7;
886                         continue;
887                 }
888                 if (!strncmp(arg, "--group=", 8)) {
889                         group_name = arg + 8;
890                         continue;
891                 }
892                 if (!strncmp(arg, "--enable=", 9)) {
893                         enable_service(arg + 9, 1);
894                         continue;
895                 }
896                 if (!strncmp(arg, "--disable=", 10)) {
897                         enable_service(arg + 10, 0);
898                         continue;
899                 }
900                 if (!strncmp(arg, "--allow-override=", 17)) {
901                         make_service_overridable(arg + 17, 1);
902                         continue;
903                 }
904                 if (!strncmp(arg, "--forbid-override=", 18)) {
905                         make_service_overridable(arg + 18, 0);
906                         continue;
907                 }
908                 if (!strcmp(arg, "--")) {
909                         ok_paths = &argv[i+1];
910                         break;
911                 } else if (arg[0] != '-') {
912                         ok_paths = &argv[i];
913                         break;
914                 }
915
916                 usage(daemon_usage);
917         }
918
919         if (inetd_mode && (group_name || user_name))
920                 die("--user and --group are incompatible with --inetd");
921
922         if (group_name && !user_name)
923                 die("--group supplied without --user");
924
925         if (user_name) {
926                 pass = getpwnam(user_name);
927                 if (!pass)
928                         die("user not found - %s", user_name);
929
930                 if (!group_name)
931                         gid = pass->pw_gid;
932                 else {
933                         group = getgrnam(group_name);
934                         if (!group)
935                                 die("group not found - %s", group_name);
936
937                         gid = group->gr_gid;
938                 }
939         }
940
941         if (log_syslog) {
942                 openlog("git-daemon", 0, LOG_DAEMON);
943                 set_die_routine(daemon_die);
944         }
945
946         if (strict_paths && (!ok_paths || !*ok_paths))
947                 die("option --strict-paths requires a whitelist");
948
949         if (inetd_mode) {
950                 struct sockaddr_storage ss;
951                 struct sockaddr *peer = (struct sockaddr *)&ss;
952                 socklen_t slen = sizeof(ss);
953
954                 freopen("/dev/null", "w", stderr);
955
956                 if (getpeername(0, peer, &slen))
957                         peer = NULL;
958
959                 return execute(peer);
960         }
961
962         if (detach)
963                 daemonize();
964         else
965                 sanitize_stdfds();
966
967         if (pid_file)
968                 store_pid(pid_file);
969
970         return serve(port, pass, gid);
971 }