daemon.c: fix segfault on OS X
[git/git.git] / daemon.c
1 #include "cache.h"
2 #include "pkt-line.h"
3 #include "exec_cmd.h"
4
5 #include <syslog.h>
6
7 #ifndef HOST_NAME_MAX
8 #define HOST_NAME_MAX 256
9 #endif
10
11 #ifndef NI_MAXSERV
12 #define NI_MAXSERV 32
13 #endif
14
15 static int log_syslog;
16 static int verbose;
17 static int reuseaddr;
18
19 static const char daemon_usage[] =
20 "git daemon [--verbose] [--syslog] [--export-all]\n"
21 " [--timeout=n] [--init-timeout=n] [--max-connections=n]\n"
22 " [--strict-paths] [--base-path=path] [--base-path-relaxed]\n"
23 " [--user-path | --user-path=path]\n"
24 " [--interpolated-path=path]\n"
25 " [--reuseaddr] [--detach] [--pid-file=file]\n"
26 " [--[enable|disable|allow-override|forbid-override]=service]\n"
27 " [--inetd | [--listen=host_or_ipaddr] [--port=n]\n"
28 " [--user=user [--group=group]]\n"
29 " [directory...]";
30
31 /* List of acceptable pathname prefixes */
32 static char **ok_paths;
33 static int strict_paths;
34
35 /* If this is set, git-daemon-export-ok is not required */
36 static int export_all_trees;
37
38 /* Take all paths relative to this one if non-NULL */
39 static char *base_path;
40 static char *interpolated_path;
41 static int base_path_relaxed;
42
43 /* Flag indicating client sent extra args. */
44 static int saw_extended_args;
45
46 /* If defined, ~user notation is allowed and the string is inserted
47 * after ~user/. E.g. a request to git://host/~alice/frotz would
48 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
49 */
50 static const char *user_path;
51
52 /* Timeout, and initial timeout */
53 static unsigned int timeout;
54 static unsigned int init_timeout;
55
56 static char *hostname;
57 static char *canon_hostname;
58 static char *ip_address;
59 static char *tcp_port;
60
61 static void logreport(int priority, const char *err, va_list params)
62 {
63 if (log_syslog) {
64 char buf[1024];
65 vsnprintf(buf, sizeof(buf), err, params);
66 syslog(priority, "%s", buf);
67 } else {
68 /*
69 * Since stderr is set to linebuffered mode, the
70 * logging of different processes will not overlap
71 */
72 fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
73 vfprintf(stderr, err, params);
74 fputc('\n', stderr);
75 }
76 }
77
78 static void logerror(const char *err, ...)
79 {
80 va_list params;
81 va_start(params, err);
82 logreport(LOG_ERR, err, params);
83 va_end(params);
84 }
85
86 static void loginfo(const char *err, ...)
87 {
88 va_list params;
89 if (!verbose)
90 return;
91 va_start(params, err);
92 logreport(LOG_INFO, err, params);
93 va_end(params);
94 }
95
96 static void NORETURN daemon_die(const char *err, va_list params)
97 {
98 logreport(LOG_ERR, err, params);
99 exit(1);
100 }
101
102 static int avoid_alias(char *p)
103 {
104 int sl, ndot;
105
106 /*
107 * This resurrects the belts and suspenders paranoia check by HPA
108 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
109 * does not do getcwd() based path canonicalizations.
110 *
111 * sl becomes true immediately after seeing '/' and continues to
112 * be true as long as dots continue after that without intervening
113 * non-dot character.
114 */
115 if (!p || (*p != '/' && *p != '~'))
116 return -1;
117 sl = 1; ndot = 0;
118 p++;
119
120 while (1) {
121 char ch = *p++;
122 if (sl) {
123 if (ch == '.')
124 ndot++;
125 else if (ch == '/') {
126 if (ndot < 3)
127 /* reject //, /./ and /../ */
128 return -1;
129 ndot = 0;
130 }
131 else if (ch == 0) {
132 if (0 < ndot && ndot < 3)
133 /* reject /.$ and /..$ */
134 return -1;
135 return 0;
136 }
137 else
138 sl = ndot = 0;
139 }
140 else if (ch == 0)
141 return 0;
142 else if (ch == '/') {
143 sl = 1;
144 ndot = 0;
145 }
146 }
147 }
148
149 static char *path_ok(char *directory)
150 {
151 static char rpath[PATH_MAX];
152 static char interp_path[PATH_MAX];
153 char *path;
154 char *dir;
155
156 dir = directory;
157
158 if (avoid_alias(dir)) {
159 logerror("'%s': aliased", dir);
160 return NULL;
161 }
162
163 if (*dir == '~') {
164 if (!user_path) {
165 logerror("'%s': User-path not allowed", dir);
166 return NULL;
167 }
168 if (*user_path) {
169 /* Got either "~alice" or "~alice/foo";
170 * rewrite them to "~alice/%s" or
171 * "~alice/%s/foo".
172 */
173 int namlen, restlen = strlen(dir);
174 char *slash = strchr(dir, '/');
175 if (!slash)
176 slash = dir + restlen;
177 namlen = slash - dir;
178 restlen -= namlen;
179 loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
180 snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
181 namlen, dir, user_path, restlen, slash);
182 dir = rpath;
183 }
184 }
185 else if (interpolated_path && saw_extended_args) {
186 struct strbuf expanded_path = STRBUF_INIT;
187 struct strbuf_expand_dict_entry dict[] = {
188 { "H", hostname },
189 { "CH", canon_hostname },
190 { "IP", ip_address },
191 { "P", tcp_port },
192 { "D", directory },
193 { "%", "%" },
194 { NULL }
195 };
196
197 if (*dir != '/') {
198 /* Allow only absolute */
199 logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
200 return NULL;
201 }
202
203 strbuf_expand(&expanded_path, interpolated_path,
204 strbuf_expand_dict_cb, &dict);
205 strlcpy(interp_path, expanded_path.buf, PATH_MAX);
206 strbuf_release(&expanded_path);
207 loginfo("Interpolated dir '%s'", interp_path);
208
209 dir = interp_path;
210 }
211 else if (base_path) {
212 if (*dir != '/') {
213 /* Allow only absolute */
214 logerror("'%s': Non-absolute path denied (base-path active)", dir);
215 return NULL;
216 }
217 snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
218 dir = rpath;
219 }
220
221 path = enter_repo(dir, strict_paths);
222 if (!path && base_path && base_path_relaxed) {
223 /*
224 * if we fail and base_path_relaxed is enabled, try without
225 * prefixing the base path
226 */
227 dir = directory;
228 path = enter_repo(dir, strict_paths);
229 }
230
231 if (!path) {
232 logerror("'%s' does not appear to be a git repository", dir);
233 return NULL;
234 }
235
236 if ( ok_paths && *ok_paths ) {
237 char **pp;
238 int pathlen = strlen(path);
239
240 /* The validation is done on the paths after enter_repo
241 * appends optional {.git,.git/.git} and friends, but
242 * it does not use getcwd(). So if your /pub is
243 * a symlink to /mnt/pub, you can whitelist /pub and
244 * do not have to say /mnt/pub.
245 * Do not say /pub/.
246 */
247 for ( pp = ok_paths ; *pp ; pp++ ) {
248 int len = strlen(*pp);
249 if (len <= pathlen &&
250 !memcmp(*pp, path, len) &&
251 (path[len] == '\0' ||
252 (!strict_paths && path[len] == '/')))
253 return path;
254 }
255 }
256 else {
257 /* be backwards compatible */
258 if (!strict_paths)
259 return path;
260 }
261
262 logerror("'%s': not in whitelist", path);
263 return NULL; /* Fallthrough. Deny by default */
264 }
265
266 typedef int (*daemon_service_fn)(void);
267 struct daemon_service {
268 const char *name;
269 const char *config_name;
270 daemon_service_fn fn;
271 int enabled;
272 int overridable;
273 };
274
275 static struct daemon_service *service_looking_at;
276 static int service_enabled;
277
278 static int git_daemon_config(const char *var, const char *value, void *cb)
279 {
280 if (!prefixcmp(var, "daemon.") &&
281 !strcmp(var + 7, service_looking_at->config_name)) {
282 service_enabled = git_config_bool(var, value);
283 return 0;
284 }
285
286 /* we are not interested in parsing any other configuration here */
287 return 0;
288 }
289
290 static int run_service(char *dir, struct daemon_service *service)
291 {
292 const char *path;
293 int enabled = service->enabled;
294
295 loginfo("Request %s for '%s'", service->name, dir);
296
297 if (!enabled && !service->overridable) {
298 logerror("'%s': service not enabled.", service->name);
299 errno = EACCES;
300 return -1;
301 }
302
303 if (!(path = path_ok(dir)))
304 return -1;
305
306 /*
307 * Security on the cheap.
308 *
309 * We want a readable HEAD, usable "objects" directory, and
310 * a "git-daemon-export-ok" flag that says that the other side
311 * is ok with us doing this.
312 *
313 * path_ok() uses enter_repo() and does whitelist checking.
314 * We only need to make sure the repository is exported.
315 */
316
317 if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
318 logerror("'%s': repository not exported.", path);
319 errno = EACCES;
320 return -1;
321 }
322
323 if (service->overridable) {
324 service_looking_at = service;
325 service_enabled = -1;
326 git_config(git_daemon_config, NULL);
327 if (0 <= service_enabled)
328 enabled = service_enabled;
329 }
330 if (!enabled) {
331 logerror("'%s': service not enabled for '%s'",
332 service->name, path);
333 errno = EACCES;
334 return -1;
335 }
336
337 /*
338 * We'll ignore SIGTERM from now on, we have a
339 * good client.
340 */
341 signal(SIGTERM, SIG_IGN);
342
343 return service->fn();
344 }
345
346 static int upload_pack(void)
347 {
348 /* Timeout as string */
349 char timeout_buf[64];
350
351 snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
352
353 /* git-upload-pack only ever reads stuff, so this is safe */
354 execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL);
355 return -1;
356 }
357
358 static int upload_archive(void)
359 {
360 execl_git_cmd("upload-archive", ".", NULL);
361 return -1;
362 }
363
364 static int receive_pack(void)
365 {
366 execl_git_cmd("receive-pack", ".", NULL);
367 return -1;
368 }
369
370 static struct daemon_service daemon_service[] = {
371 { "upload-archive", "uploadarch", upload_archive, 0, 1 },
372 { "upload-pack", "uploadpack", upload_pack, 1, 1 },
373 { "receive-pack", "receivepack", receive_pack, 0, 1 },
374 };
375
376 static void enable_service(const char *name, int ena)
377 {
378 int i;
379 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
380 if (!strcmp(daemon_service[i].name, name)) {
381 daemon_service[i].enabled = ena;
382 return;
383 }
384 }
385 die("No such service %s", name);
386 }
387
388 static void make_service_overridable(const char *name, int ena)
389 {
390 int i;
391 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
392 if (!strcmp(daemon_service[i].name, name)) {
393 daemon_service[i].overridable = ena;
394 return;
395 }
396 }
397 die("No such service %s", name);
398 }
399
400 static char *xstrdup_tolower(const char *str)
401 {
402 char *p, *dup = xstrdup(str);
403 for (p = dup; *p; p++)
404 *p = tolower(*p);
405 return dup;
406 }
407
408 /*
409 * Separate the "extra args" information as supplied by the client connection.
410 */
411 static void parse_extra_args(char *extra_args, int buflen)
412 {
413 char *val;
414 int vallen;
415 char *end = extra_args + buflen;
416
417 while (extra_args < end && *extra_args) {
418 saw_extended_args = 1;
419 if (strncasecmp("host=", extra_args, 5) == 0) {
420 val = extra_args + 5;
421 vallen = strlen(val) + 1;
422 if (*val) {
423 /* Split <host>:<port> at colon. */
424 char *host = val;
425 char *port = strrchr(host, ':');
426 if (port) {
427 *port = 0;
428 port++;
429 free(tcp_port);
430 tcp_port = xstrdup(port);
431 }
432 free(hostname);
433 hostname = xstrdup_tolower(host);
434 }
435
436 /* On to the next one */
437 extra_args = val + vallen;
438 }
439 }
440
441 /*
442 * Locate canonical hostname and its IP address.
443 */
444 if (hostname) {
445 #ifndef NO_IPV6
446 struct addrinfo hints;
447 struct addrinfo *ai;
448 int gai;
449 static char addrbuf[HOST_NAME_MAX + 1];
450
451 memset(&hints, 0, sizeof(hints));
452 hints.ai_flags = AI_CANONNAME;
453
454 gai = getaddrinfo(hostname, 0, &hints, &ai);
455 if (!gai) {
456 struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
457
458 inet_ntop(AF_INET, &sin_addr->sin_addr,
459 addrbuf, sizeof(addrbuf));
460 free(ip_address);
461 ip_address = xstrdup(addrbuf);
462
463 free(canon_hostname);
464 canon_hostname = xstrdup(ai->ai_canonname ?
465 ai->ai_canonname : ip_address);
466
467 freeaddrinfo(ai);
468 }
469 #else
470 struct hostent *hent;
471 struct sockaddr_in sa;
472 char **ap;
473 static char addrbuf[HOST_NAME_MAX + 1];
474
475 hent = gethostbyname(hostname);
476
477 ap = hent->h_addr_list;
478 memset(&sa, 0, sizeof sa);
479 sa.sin_family = hent->h_addrtype;
480 sa.sin_port = htons(0);
481 memcpy(&sa.sin_addr, *ap, hent->h_length);
482
483 inet_ntop(hent->h_addrtype, &sa.sin_addr,
484 addrbuf, sizeof(addrbuf));
485
486 free(canon_hostname);
487 canon_hostname = xstrdup(hent->h_name);
488 free(ip_address);
489 ip_address = xstrdup(addrbuf);
490 #endif
491 }
492 }
493
494
495 static int execute(struct sockaddr *addr)
496 {
497 static char line[1000];
498 int pktlen, len, i;
499
500 if (addr) {
501 char addrbuf[256] = "";
502 int port = -1;
503
504 if (addr->sa_family == AF_INET) {
505 struct sockaddr_in *sin_addr = (void *) addr;
506 inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
507 port = ntohs(sin_addr->sin_port);
508 #ifndef NO_IPV6
509 } else if (addr && addr->sa_family == AF_INET6) {
510 struct sockaddr_in6 *sin6_addr = (void *) addr;
511
512 char *buf = addrbuf;
513 *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
514 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
515 strcat(buf, "]");
516
517 port = ntohs(sin6_addr->sin6_port);
518 #endif
519 }
520 loginfo("Connection from %s:%d", addrbuf, port);
521 setenv("REMOTE_ADDR", addrbuf, 1);
522 }
523 else {
524 unsetenv("REMOTE_ADDR");
525 }
526
527 alarm(init_timeout ? init_timeout : timeout);
528 pktlen = packet_read_line(0, line, sizeof(line));
529 alarm(0);
530
531 len = strlen(line);
532 if (pktlen != len)
533 loginfo("Extended attributes (%d bytes) exist <%.*s>",
534 (int) pktlen - len,
535 (int) pktlen - len, line + len + 1);
536 if (len && line[len-1] == '\n') {
537 line[--len] = 0;
538 pktlen--;
539 }
540
541 free(hostname);
542 free(canon_hostname);
543 free(ip_address);
544 free(tcp_port);
545 hostname = canon_hostname = ip_address = tcp_port = NULL;
546
547 if (len != pktlen)
548 parse_extra_args(line + len + 1, pktlen - len - 1);
549
550 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
551 struct daemon_service *s = &(daemon_service[i]);
552 int namelen = strlen(s->name);
553 if (!prefixcmp(line, "git-") &&
554 !strncmp(s->name, line + 4, namelen) &&
555 line[namelen + 4] == ' ') {
556 /*
557 * Note: The directory here is probably context sensitive,
558 * and might depend on the actual service being performed.
559 */
560 return run_service(line + namelen + 5, s);
561 }
562 }
563
564 logerror("Protocol error: '%s'", line);
565 return -1;
566 }
567
568 static int max_connections = 32;
569
570 static unsigned int live_children;
571
572 static struct child {
573 struct child *next;
574 pid_t pid;
575 struct sockaddr_storage address;
576 } *firstborn;
577
578 static void add_child(pid_t pid, struct sockaddr *addr, int addrlen)
579 {
580 struct child *newborn, **cradle;
581
582 /*
583 * This must be xcalloc() -- we'll compare the whole sockaddr_storage
584 * but individual address may be shorter.
585 */
586 newborn = xcalloc(1, sizeof(*newborn));
587 live_children++;
588 newborn->pid = pid;
589 memcpy(&newborn->address, addr, addrlen);
590 for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
591 if (!memcmp(&(*cradle)->address, &newborn->address,
592 sizeof(newborn->address)))
593 break;
594 newborn->next = *cradle;
595 *cradle = newborn;
596 }
597
598 static void remove_child(pid_t pid)
599 {
600 struct child **cradle, *blanket;
601
602 for (cradle = &firstborn; (blanket = *cradle); cradle = &blanket->next)
603 if (blanket->pid == pid) {
604 *cradle = blanket->next;
605 live_children--;
606 free(blanket);
607 break;
608 }
609 }
610
611 /*
612 * This gets called if the number of connections grows
613 * past "max_connections".
614 *
615 * We kill the newest connection from a duplicate IP.
616 */
617 static void kill_some_child(void)
618 {
619 const struct child *blanket, *next;
620
621 if (!(blanket = firstborn))
622 return;
623
624 for (; (next = blanket->next); blanket = next)
625 if (!memcmp(&blanket->address, &next->address,
626 sizeof(next->address))) {
627 kill(blanket->pid, SIGTERM);
628 break;
629 }
630 }
631
632 static void check_dead_children(void)
633 {
634 int status;
635 pid_t pid;
636
637 while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
638 const char *dead = "";
639 remove_child(pid);
640 if (!WIFEXITED(status) || (WEXITSTATUS(status) > 0))
641 dead = " (with error)";
642 loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
643 }
644 }
645
646 static void handle(int incoming, struct sockaddr *addr, int addrlen)
647 {
648 pid_t pid;
649
650 if (max_connections && live_children >= max_connections) {
651 kill_some_child();
652 sleep(1); /* give it some time to die */
653 check_dead_children();
654 if (live_children >= max_connections) {
655 close(incoming);
656 logerror("Too many children, dropping connection");
657 return;
658 }
659 }
660
661 if ((pid = fork())) {
662 close(incoming);
663 if (pid < 0) {
664 logerror("Couldn't fork %s", strerror(errno));
665 return;
666 }
667
668 add_child(pid, addr, addrlen);
669 return;
670 }
671
672 dup2(incoming, 0);
673 dup2(incoming, 1);
674 close(incoming);
675
676 exit(execute(addr));
677 }
678
679 static void child_handler(int signo)
680 {
681 /*
682 * Otherwise empty handler because systemcalls will get interrupted
683 * upon signal receipt
684 * SysV needs the handler to be rearmed
685 */
686 signal(SIGCHLD, child_handler);
687 }
688
689 static int set_reuse_addr(int sockfd)
690 {
691 int on = 1;
692
693 if (!reuseaddr)
694 return 0;
695 return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
696 &on, sizeof(on));
697 }
698
699 #ifndef NO_IPV6
700
701 static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
702 {
703 int socknum = 0, *socklist = NULL;
704 int maxfd = -1;
705 char pbuf[NI_MAXSERV];
706 struct addrinfo hints, *ai0, *ai;
707 int gai;
708 long flags;
709
710 sprintf(pbuf, "%d", listen_port);
711 memset(&hints, 0, sizeof(hints));
712 hints.ai_family = AF_UNSPEC;
713 hints.ai_socktype = SOCK_STREAM;
714 hints.ai_protocol = IPPROTO_TCP;
715 hints.ai_flags = AI_PASSIVE;
716
717 gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
718 if (gai)
719 die("getaddrinfo() failed: %s", gai_strerror(gai));
720
721 for (ai = ai0; ai; ai = ai->ai_next) {
722 int sockfd;
723
724 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
725 if (sockfd < 0)
726 continue;
727 if (sockfd >= FD_SETSIZE) {
728 logerror("Socket descriptor too large");
729 close(sockfd);
730 continue;
731 }
732
733 #ifdef IPV6_V6ONLY
734 if (ai->ai_family == AF_INET6) {
735 int on = 1;
736 setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
737 &on, sizeof(on));
738 /* Note: error is not fatal */
739 }
740 #endif
741
742 if (set_reuse_addr(sockfd)) {
743 close(sockfd);
744 continue;
745 }
746
747 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
748 close(sockfd);
749 continue; /* not fatal */
750 }
751 if (listen(sockfd, 5) < 0) {
752 close(sockfd);
753 continue; /* not fatal */
754 }
755
756 flags = fcntl(sockfd, F_GETFD, 0);
757 if (flags >= 0)
758 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
759
760 socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
761 socklist[socknum++] = sockfd;
762
763 if (maxfd < sockfd)
764 maxfd = sockfd;
765 }
766
767 freeaddrinfo(ai0);
768
769 *socklist_p = socklist;
770 return socknum;
771 }
772
773 #else /* NO_IPV6 */
774
775 static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
776 {
777 struct sockaddr_in sin;
778 int sockfd;
779 long flags;
780
781 memset(&sin, 0, sizeof sin);
782 sin.sin_family = AF_INET;
783 sin.sin_port = htons(listen_port);
784
785 if (listen_addr) {
786 /* Well, host better be an IP address here. */
787 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
788 return 0;
789 } else {
790 sin.sin_addr.s_addr = htonl(INADDR_ANY);
791 }
792
793 sockfd = socket(AF_INET, SOCK_STREAM, 0);
794 if (sockfd < 0)
795 return 0;
796
797 if (set_reuse_addr(sockfd)) {
798 close(sockfd);
799 return 0;
800 }
801
802 if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
803 close(sockfd);
804 return 0;
805 }
806
807 if (listen(sockfd, 5) < 0) {
808 close(sockfd);
809 return 0;
810 }
811
812 flags = fcntl(sockfd, F_GETFD, 0);
813 if (flags >= 0)
814 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
815
816 *socklist_p = xmalloc(sizeof(int));
817 **socklist_p = sockfd;
818 return 1;
819 }
820
821 #endif
822
823 static int service_loop(int socknum, int *socklist)
824 {
825 struct pollfd *pfd;
826 int i;
827
828 pfd = xcalloc(socknum, sizeof(struct pollfd));
829
830 for (i = 0; i < socknum; i++) {
831 pfd[i].fd = socklist[i];
832 pfd[i].events = POLLIN;
833 }
834
835 signal(SIGCHLD, child_handler);
836
837 for (;;) {
838 int i;
839
840 check_dead_children();
841
842 if (poll(pfd, socknum, -1) < 0) {
843 if (errno != EINTR) {
844 logerror("Poll failed, resuming: %s",
845 strerror(errno));
846 sleep(1);
847 }
848 continue;
849 }
850
851 for (i = 0; i < socknum; i++) {
852 if (pfd[i].revents & POLLIN) {
853 struct sockaddr_storage ss;
854 unsigned int sslen = sizeof(ss);
855 int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
856 if (incoming < 0) {
857 switch (errno) {
858 case EAGAIN:
859 case EINTR:
860 case ECONNABORTED:
861 continue;
862 default:
863 die("accept returned %s", strerror(errno));
864 }
865 }
866 handle(incoming, (struct sockaddr *)&ss, sslen);
867 }
868 }
869 }
870 }
871
872 /* if any standard file descriptor is missing open it to /dev/null */
873 static void sanitize_stdfds(void)
874 {
875 int fd = open("/dev/null", O_RDWR, 0);
876 while (fd != -1 && fd < 2)
877 fd = dup(fd);
878 if (fd == -1)
879 die("open /dev/null or dup failed: %s", strerror(errno));
880 if (fd > 2)
881 close(fd);
882 }
883
884 static void daemonize(void)
885 {
886 switch (fork()) {
887 case 0:
888 break;
889 case -1:
890 die("fork failed: %s", strerror(errno));
891 default:
892 exit(0);
893 }
894 if (setsid() == -1)
895 die("setsid failed: %s", strerror(errno));
896 close(0);
897 close(1);
898 close(2);
899 sanitize_stdfds();
900 }
901
902 static void store_pid(const char *path)
903 {
904 FILE *f = fopen(path, "w");
905 if (!f)
906 die("cannot open pid file %s: %s", path, strerror(errno));
907 if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0)
908 die("failed to write pid file %s: %s", path, strerror(errno));
909 }
910
911 static int serve(char *listen_addr, int listen_port, struct passwd *pass, gid_t gid)
912 {
913 int socknum, *socklist;
914
915 socknum = socksetup(listen_addr, listen_port, &socklist);
916 if (socknum == 0)
917 die("unable to allocate any listen sockets on host %s port %u",
918 listen_addr, listen_port);
919
920 if (pass && gid &&
921 (initgroups(pass->pw_name, gid) || setgid (gid) ||
922 setuid(pass->pw_uid)))
923 die("cannot drop privileges");
924
925 return service_loop(socknum, socklist);
926 }
927
928 int main(int argc, char **argv)
929 {
930 int listen_port = 0;
931 char *listen_addr = NULL;
932 int inetd_mode = 0;
933 const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
934 int detach = 0;
935 struct passwd *pass = NULL;
936 struct group *group;
937 gid_t gid = 0;
938 int i;
939
940 git_extract_argv0_path(argv[0]);
941
942 for (i = 1; i < argc; i++) {
943 char *arg = argv[i];
944
945 if (!prefixcmp(arg, "--listen=")) {
946 listen_addr = xstrdup_tolower(arg + 9);
947 continue;
948 }
949 if (!prefixcmp(arg, "--port=")) {
950 char *end;
951 unsigned long n;
952 n = strtoul(arg+7, &end, 0);
953 if (arg[7] && !*end) {
954 listen_port = n;
955 continue;
956 }
957 }
958 if (!strcmp(arg, "--inetd")) {
959 inetd_mode = 1;
960 log_syslog = 1;
961 continue;
962 }
963 if (!strcmp(arg, "--verbose")) {
964 verbose = 1;
965 continue;
966 }
967 if (!strcmp(arg, "--syslog")) {
968 log_syslog = 1;
969 continue;
970 }
971 if (!strcmp(arg, "--export-all")) {
972 export_all_trees = 1;
973 continue;
974 }
975 if (!prefixcmp(arg, "--timeout=")) {
976 timeout = atoi(arg+10);
977 continue;
978 }
979 if (!prefixcmp(arg, "--init-timeout=")) {
980 init_timeout = atoi(arg+15);
981 continue;
982 }
983 if (!prefixcmp(arg, "--max-connections=")) {
984 max_connections = atoi(arg+18);
985 if (max_connections < 0)
986 max_connections = 0; /* unlimited */
987 continue;
988 }
989 if (!strcmp(arg, "--strict-paths")) {
990 strict_paths = 1;
991 continue;
992 }
993 if (!prefixcmp(arg, "--base-path=")) {
994 base_path = arg+12;
995 continue;
996 }
997 if (!strcmp(arg, "--base-path-relaxed")) {
998 base_path_relaxed = 1;
999 continue;
1000 }
1001 if (!prefixcmp(arg, "--interpolated-path=")) {
1002 interpolated_path = arg+20;
1003 continue;
1004 }
1005 if (!strcmp(arg, "--reuseaddr")) {
1006 reuseaddr = 1;
1007 continue;
1008 }
1009 if (!strcmp(arg, "--user-path")) {
1010 user_path = "";
1011 continue;
1012 }
1013 if (!prefixcmp(arg, "--user-path=")) {
1014 user_path = arg + 12;
1015 continue;
1016 }
1017 if (!prefixcmp(arg, "--pid-file=")) {
1018 pid_file = arg + 11;
1019 continue;
1020 }
1021 if (!strcmp(arg, "--detach")) {
1022 detach = 1;
1023 log_syslog = 1;
1024 continue;
1025 }
1026 if (!prefixcmp(arg, "--user=")) {
1027 user_name = arg + 7;
1028 continue;
1029 }
1030 if (!prefixcmp(arg, "--group=")) {
1031 group_name = arg + 8;
1032 continue;
1033 }
1034 if (!prefixcmp(arg, "--enable=")) {
1035 enable_service(arg + 9, 1);
1036 continue;
1037 }
1038 if (!prefixcmp(arg, "--disable=")) {
1039 enable_service(arg + 10, 0);
1040 continue;
1041 }
1042 if (!prefixcmp(arg, "--allow-override=")) {
1043 make_service_overridable(arg + 17, 1);
1044 continue;
1045 }
1046 if (!prefixcmp(arg, "--forbid-override=")) {
1047 make_service_overridable(arg + 18, 0);
1048 continue;
1049 }
1050 if (!strcmp(arg, "--")) {
1051 ok_paths = &argv[i+1];
1052 break;
1053 } else if (arg[0] != '-') {
1054 ok_paths = &argv[i];
1055 break;
1056 }
1057
1058 usage(daemon_usage);
1059 }
1060
1061 if (log_syslog) {
1062 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1063 set_die_routine(daemon_die);
1064 } else
1065 /* avoid splitting a message in the middle */
1066 setvbuf(stderr, NULL, _IOLBF, 0);
1067
1068 if (inetd_mode && (group_name || user_name))
1069 die("--user and --group are incompatible with --inetd");
1070
1071 if (inetd_mode && (listen_port || listen_addr))
1072 die("--listen= and --port= are incompatible with --inetd");
1073 else if (listen_port == 0)
1074 listen_port = DEFAULT_GIT_PORT;
1075
1076 if (group_name && !user_name)
1077 die("--group supplied without --user");
1078
1079 if (user_name) {
1080 pass = getpwnam(user_name);
1081 if (!pass)
1082 die("user not found - %s", user_name);
1083
1084 if (!group_name)
1085 gid = pass->pw_gid;
1086 else {
1087 group = getgrnam(group_name);
1088 if (!group)
1089 die("group not found - %s", group_name);
1090
1091 gid = group->gr_gid;
1092 }
1093 }
1094
1095 if (strict_paths && (!ok_paths || !*ok_paths))
1096 die("option --strict-paths requires a whitelist");
1097
1098 if (base_path && !is_directory(base_path))
1099 die("base-path '%s' does not exist or is not a directory",
1100 base_path);
1101
1102 if (inetd_mode) {
1103 struct sockaddr_storage ss;
1104 struct sockaddr *peer = (struct sockaddr *)&ss;
1105 socklen_t slen = sizeof(ss);
1106
1107 if (!freopen("/dev/null", "w", stderr))
1108 die("failed to redirect stderr to /dev/null: %s",
1109 strerror(errno));
1110
1111 if (getpeername(0, peer, &slen))
1112 peer = NULL;
1113
1114 return execute(peer);
1115 }
1116
1117 if (detach) {
1118 daemonize();
1119 loginfo("Ready to rumble");
1120 }
1121 else
1122 sanitize_stdfds();
1123
1124 if (pid_file)
1125 store_pid(pid_file);
1126
1127 return serve(listen_addr, listen_port, pass, gid);
1128 }