contrib/hooks/post-receive-email: remove cruft, $committer is not used
[git/git.git] / daemon.c
1 #include "cache.h"
2 #include "pkt-line.h"
3 #include "exec_cmd.h"
4 #include "interpolate.h"
5
6 #include <syslog.h>
7
8 #ifndef HOST_NAME_MAX
9 #define HOST_NAME_MAX 256
10 #endif
11
12 #ifndef NI_MAXSERV
13 #define NI_MAXSERV 32
14 #endif
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] [--export-all]\n"
22 " [--timeout=n] [--init-timeout=n] [--strict-paths]\n"
23 " [--base-path=path] [--base-path-relaxed]\n"
24 " [--user-path | --user-path=path]\n"
25 " [--interpolated-path=path]\n"
26 " [--reuseaddr] [--detach] [--pid-file=file]\n"
27 " [--[enable|disable|allow-override|forbid-override]=service]\n"
28 " [--inetd | [--listen=host_or_ipaddr] [--port=n]\n"
29 " [--user=user [--group=group]]\n"
30 " [directory...]";
31
32 /* List of acceptable pathname prefixes */
33 static char **ok_paths;
34 static int strict_paths;
35
36 /* If this is set, git-daemon-export-ok is not required */
37 static int export_all_trees;
38
39 /* Take all paths relative to this one if non-NULL */
40 static char *base_path;
41 static char *interpolated_path;
42 static int base_path_relaxed;
43
44 /* Flag indicating client sent extra args. */
45 static int saw_extended_args;
46
47 /* If defined, ~user notation is allowed and the string is inserted
48 * after ~user/. E.g. a request to git://host/~alice/frotz would
49 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
50 */
51 static const char *user_path;
52
53 /* Timeout, and initial timeout */
54 static unsigned int timeout;
55 static unsigned int init_timeout;
56
57 /*
58 * Static table for now. Ugh.
59 * Feel free to make dynamic as needed.
60 */
61 #define INTERP_SLOT_HOST (0)
62 #define INTERP_SLOT_CANON_HOST (1)
63 #define INTERP_SLOT_IP (2)
64 #define INTERP_SLOT_PORT (3)
65 #define INTERP_SLOT_DIR (4)
66 #define INTERP_SLOT_PERCENT (5)
67
68 static struct interp interp_table[] = {
69 { "%H", 0},
70 { "%CH", 0},
71 { "%IP", 0},
72 { "%P", 0},
73 { "%D", 0},
74 { "%%", 0},
75 };
76
77
78 static void logreport(int priority, const char *err, va_list params)
79 {
80 /* We should do a single write so that it is atomic and output
81 * of several processes do not get intermingled. */
82 char buf[1024];
83 int buflen;
84 int maxlen, msglen;
85
86 /* sizeof(buf) should be big enough for "[pid] \n" */
87 buflen = snprintf(buf, sizeof(buf), "[%ld] ", (long) getpid());
88
89 maxlen = sizeof(buf) - buflen - 1; /* -1 for our own LF */
90 msglen = vsnprintf(buf + buflen, maxlen, err, params);
91
92 if (log_syslog) {
93 syslog(priority, "%s", buf);
94 return;
95 }
96
97 /* maxlen counted our own LF but also counts space given to
98 * vsnprintf for the terminating NUL. We want to make sure that
99 * we have space for our own LF and NUL after the "meat" of the
100 * message, so truncate it at maxlen - 1.
101 */
102 if (msglen > maxlen - 1)
103 msglen = maxlen - 1;
104 else if (msglen < 0)
105 msglen = 0; /* Protect against weird return values. */
106 buflen += msglen;
107
108 buf[buflen++] = '\n';
109 buf[buflen] = '\0';
110
111 write_in_full(2, buf, buflen);
112 }
113
114 static void logerror(const char *err, ...)
115 {
116 va_list params;
117 va_start(params, err);
118 logreport(LOG_ERR, err, params);
119 va_end(params);
120 }
121
122 static void loginfo(const char *err, ...)
123 {
124 va_list params;
125 if (!verbose)
126 return;
127 va_start(params, err);
128 logreport(LOG_INFO, err, params);
129 va_end(params);
130 }
131
132 static void NORETURN daemon_die(const char *err, va_list params)
133 {
134 logreport(LOG_ERR, err, params);
135 exit(1);
136 }
137
138 static int avoid_alias(char *p)
139 {
140 int sl, ndot;
141
142 /*
143 * This resurrects the belts and suspenders paranoia check by HPA
144 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
145 * does not do getcwd() based path canonicalizations.
146 *
147 * sl becomes true immediately after seeing '/' and continues to
148 * be true as long as dots continue after that without intervening
149 * non-dot character.
150 */
151 if (!p || (*p != '/' && *p != '~'))
152 return -1;
153 sl = 1; ndot = 0;
154 p++;
155
156 while (1) {
157 char ch = *p++;
158 if (sl) {
159 if (ch == '.')
160 ndot++;
161 else if (ch == '/') {
162 if (ndot < 3)
163 /* reject //, /./ and /../ */
164 return -1;
165 ndot = 0;
166 }
167 else if (ch == 0) {
168 if (0 < ndot && ndot < 3)
169 /* reject /.$ and /..$ */
170 return -1;
171 return 0;
172 }
173 else
174 sl = ndot = 0;
175 }
176 else if (ch == 0)
177 return 0;
178 else if (ch == '/') {
179 sl = 1;
180 ndot = 0;
181 }
182 }
183 }
184
185 static char *path_ok(struct interp *itable)
186 {
187 static char rpath[PATH_MAX];
188 static char interp_path[PATH_MAX];
189 int retried_path = 0;
190 char *path;
191 char *dir;
192
193 dir = itable[INTERP_SLOT_DIR].value;
194
195 if (avoid_alias(dir)) {
196 logerror("'%s': aliased", dir);
197 return NULL;
198 }
199
200 if (*dir == '~') {
201 if (!user_path) {
202 logerror("'%s': User-path not allowed", dir);
203 return NULL;
204 }
205 if (*user_path) {
206 /* Got either "~alice" or "~alice/foo";
207 * rewrite them to "~alice/%s" or
208 * "~alice/%s/foo".
209 */
210 int namlen, restlen = strlen(dir);
211 char *slash = strchr(dir, '/');
212 if (!slash)
213 slash = dir + restlen;
214 namlen = slash - dir;
215 restlen -= namlen;
216 loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
217 snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
218 namlen, dir, user_path, restlen, slash);
219 dir = rpath;
220 }
221 }
222 else if (interpolated_path && saw_extended_args) {
223 if (*dir != '/') {
224 /* Allow only absolute */
225 logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
226 return NULL;
227 }
228
229 interpolate(interp_path, PATH_MAX, interpolated_path,
230 interp_table, ARRAY_SIZE(interp_table));
231 loginfo("Interpolated dir '%s'", interp_path);
232
233 dir = interp_path;
234 }
235 else if (base_path) {
236 if (*dir != '/') {
237 /* Allow only absolute */
238 logerror("'%s': Non-absolute path denied (base-path active)", dir);
239 return NULL;
240 }
241 snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
242 dir = rpath;
243 }
244
245 do {
246 path = enter_repo(dir, strict_paths);
247 if (path)
248 break;
249
250 /*
251 * if we fail and base_path_relaxed is enabled, try without
252 * prefixing the base path
253 */
254 if (base_path && base_path_relaxed && !retried_path) {
255 dir = itable[INTERP_SLOT_DIR].value;
256 retried_path = 1;
257 continue;
258 }
259 break;
260 } while (1);
261
262 if (!path) {
263 logerror("'%s': unable to chdir or not a git archive", dir);
264 return NULL;
265 }
266
267 if ( ok_paths && *ok_paths ) {
268 char **pp;
269 int pathlen = strlen(path);
270
271 /* The validation is done on the paths after enter_repo
272 * appends optional {.git,.git/.git} and friends, but
273 * it does not use getcwd(). So if your /pub is
274 * a symlink to /mnt/pub, you can whitelist /pub and
275 * do not have to say /mnt/pub.
276 * Do not say /pub/.
277 */
278 for ( pp = ok_paths ; *pp ; pp++ ) {
279 int len = strlen(*pp);
280 if (len <= pathlen &&
281 !memcmp(*pp, path, len) &&
282 (path[len] == '\0' ||
283 (!strict_paths && path[len] == '/')))
284 return path;
285 }
286 }
287 else {
288 /* be backwards compatible */
289 if (!strict_paths)
290 return path;
291 }
292
293 logerror("'%s': not in whitelist", path);
294 return NULL; /* Fallthrough. Deny by default */
295 }
296
297 typedef int (*daemon_service_fn)(void);
298 struct daemon_service {
299 const char *name;
300 const char *config_name;
301 daemon_service_fn fn;
302 int enabled;
303 int overridable;
304 };
305
306 static struct daemon_service *service_looking_at;
307 static int service_enabled;
308
309 static int git_daemon_config(const char *var, const char *value)
310 {
311 if (!prefixcmp(var, "daemon.") &&
312 !strcmp(var + 7, service_looking_at->config_name)) {
313 service_enabled = git_config_bool(var, value);
314 return 0;
315 }
316
317 /* we are not interested in parsing any other configuration here */
318 return 0;
319 }
320
321 static int run_service(struct interp *itable, struct daemon_service *service)
322 {
323 const char *path;
324 int enabled = service->enabled;
325
326 loginfo("Request %s for '%s'",
327 service->name,
328 itable[INTERP_SLOT_DIR].value);
329
330 if (!enabled && !service->overridable) {
331 logerror("'%s': service not enabled.", service->name);
332 errno = EACCES;
333 return -1;
334 }
335
336 if (!(path = path_ok(itable)))
337 return -1;
338
339 /*
340 * Security on the cheap.
341 *
342 * We want a readable HEAD, usable "objects" directory, and
343 * a "git-daemon-export-ok" flag that says that the other side
344 * is ok with us doing this.
345 *
346 * path_ok() uses enter_repo() and does whitelist checking.
347 * We only need to make sure the repository is exported.
348 */
349
350 if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
351 logerror("'%s': repository not exported.", path);
352 errno = EACCES;
353 return -1;
354 }
355
356 if (service->overridable) {
357 service_looking_at = service;
358 service_enabled = -1;
359 git_config(git_daemon_config);
360 if (0 <= service_enabled)
361 enabled = service_enabled;
362 }
363 if (!enabled) {
364 logerror("'%s': service not enabled for '%s'",
365 service->name, path);
366 errno = EACCES;
367 return -1;
368 }
369
370 /*
371 * We'll ignore SIGTERM from now on, we have a
372 * good client.
373 */
374 signal(SIGTERM, SIG_IGN);
375
376 return service->fn();
377 }
378
379 static int upload_pack(void)
380 {
381 /* Timeout as string */
382 char timeout_buf[64];
383
384 snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
385
386 /* git-upload-pack only ever reads stuff, so this is safe */
387 execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL);
388 return -1;
389 }
390
391 static int upload_archive(void)
392 {
393 execl_git_cmd("upload-archive", ".", NULL);
394 return -1;
395 }
396
397 static int receive_pack(void)
398 {
399 execl_git_cmd("receive-pack", ".", NULL);
400 return -1;
401 }
402
403 static struct daemon_service daemon_service[] = {
404 { "upload-archive", "uploadarch", upload_archive, 0, 1 },
405 { "upload-pack", "uploadpack", upload_pack, 1, 1 },
406 { "receive-pack", "receivepack", receive_pack, 0, 1 },
407 };
408
409 static void enable_service(const char *name, int ena) {
410 int i;
411 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
412 if (!strcmp(daemon_service[i].name, name)) {
413 daemon_service[i].enabled = ena;
414 return;
415 }
416 }
417 die("No such service %s", name);
418 }
419
420 static void make_service_overridable(const char *name, int ena) {
421 int i;
422 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
423 if (!strcmp(daemon_service[i].name, name)) {
424 daemon_service[i].overridable = ena;
425 return;
426 }
427 }
428 die("No such service %s", name);
429 }
430
431 /*
432 * Separate the "extra args" information as supplied by the client connection.
433 * Any resulting data is squirreled away in the given interpolation table.
434 */
435 static void parse_extra_args(struct interp *table, char *extra_args, int buflen)
436 {
437 char *val;
438 int vallen;
439 char *end = extra_args + buflen;
440
441 while (extra_args < end && *extra_args) {
442 saw_extended_args = 1;
443 if (strncasecmp("host=", extra_args, 5) == 0) {
444 val = extra_args + 5;
445 vallen = strlen(val) + 1;
446 if (*val) {
447 /* Split <host>:<port> at colon. */
448 char *host = val;
449 char *port = strrchr(host, ':');
450 if (port) {
451 *port = 0;
452 port++;
453 interp_set_entry(table, INTERP_SLOT_PORT, port);
454 }
455 interp_set_entry(table, INTERP_SLOT_HOST, host);
456 }
457
458 /* On to the next one */
459 extra_args = val + vallen;
460 }
461 }
462 }
463
464 static void fill_in_extra_table_entries(struct interp *itable)
465 {
466 char *hp;
467
468 /*
469 * Replace literal host with lowercase-ized hostname.
470 */
471 hp = interp_table[INTERP_SLOT_HOST].value;
472 if (!hp)
473 return;
474 for ( ; *hp; hp++)
475 *hp = tolower(*hp);
476
477 /*
478 * Locate canonical hostname and its IP address.
479 */
480 #ifndef NO_IPV6
481 {
482 struct addrinfo hints;
483 struct addrinfo *ai, *ai0;
484 int gai;
485 static char addrbuf[HOST_NAME_MAX + 1];
486
487 memset(&hints, 0, sizeof(hints));
488 hints.ai_flags = AI_CANONNAME;
489
490 gai = getaddrinfo(interp_table[INTERP_SLOT_HOST].value, 0, &hints, &ai0);
491 if (!gai) {
492 for (ai = ai0; ai; ai = ai->ai_next) {
493 struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
494
495 inet_ntop(AF_INET, &sin_addr->sin_addr,
496 addrbuf, sizeof(addrbuf));
497 interp_set_entry(interp_table,
498 INTERP_SLOT_CANON_HOST, ai->ai_canonname);
499 interp_set_entry(interp_table,
500 INTERP_SLOT_IP, addrbuf);
501 break;
502 }
503 freeaddrinfo(ai0);
504 }
505 }
506 #else
507 {
508 struct hostent *hent;
509 struct sockaddr_in sa;
510 char **ap;
511 static char addrbuf[HOST_NAME_MAX + 1];
512
513 hent = gethostbyname(interp_table[INTERP_SLOT_HOST].value);
514
515 ap = hent->h_addr_list;
516 memset(&sa, 0, sizeof sa);
517 sa.sin_family = hent->h_addrtype;
518 sa.sin_port = htons(0);
519 memcpy(&sa.sin_addr, *ap, hent->h_length);
520
521 inet_ntop(hent->h_addrtype, &sa.sin_addr,
522 addrbuf, sizeof(addrbuf));
523
524 interp_set_entry(interp_table, INTERP_SLOT_CANON_HOST, hent->h_name);
525 interp_set_entry(interp_table, INTERP_SLOT_IP, addrbuf);
526 }
527 #endif
528 }
529
530
531 static int execute(struct sockaddr *addr)
532 {
533 static char line[1000];
534 int pktlen, len, i;
535
536 if (addr) {
537 char addrbuf[256] = "";
538 int port = -1;
539
540 if (addr->sa_family == AF_INET) {
541 struct sockaddr_in *sin_addr = (void *) addr;
542 inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
543 port = ntohs(sin_addr->sin_port);
544 #ifndef NO_IPV6
545 } else if (addr && addr->sa_family == AF_INET6) {
546 struct sockaddr_in6 *sin6_addr = (void *) addr;
547
548 char *buf = addrbuf;
549 *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
550 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
551 strcat(buf, "]");
552
553 port = ntohs(sin6_addr->sin6_port);
554 #endif
555 }
556 loginfo("Connection from %s:%d", addrbuf, port);
557 }
558
559 alarm(init_timeout ? init_timeout : timeout);
560 pktlen = packet_read_line(0, line, sizeof(line));
561 alarm(0);
562
563 len = strlen(line);
564 if (pktlen != len)
565 loginfo("Extended attributes (%d bytes) exist <%.*s>",
566 (int) pktlen - len,
567 (int) pktlen - len, line + len + 1);
568 if (len && line[len-1] == '\n') {
569 line[--len] = 0;
570 pktlen--;
571 }
572
573 /*
574 * Initialize the path interpolation table for this connection.
575 */
576 interp_clear_table(interp_table, ARRAY_SIZE(interp_table));
577 interp_set_entry(interp_table, INTERP_SLOT_PERCENT, "%");
578
579 if (len != pktlen) {
580 parse_extra_args(interp_table, line + len + 1, pktlen - len - 1);
581 fill_in_extra_table_entries(interp_table);
582 }
583
584 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
585 struct daemon_service *s = &(daemon_service[i]);
586 int namelen = strlen(s->name);
587 if (!prefixcmp(line, "git-") &&
588 !strncmp(s->name, line + 4, namelen) &&
589 line[namelen + 4] == ' ') {
590 /*
591 * Note: The directory here is probably context sensitive,
592 * and might depend on the actual service being performed.
593 */
594 interp_set_entry(interp_table,
595 INTERP_SLOT_DIR, line + namelen + 5);
596 return run_service(interp_table, s);
597 }
598 }
599
600 logerror("Protocol error: '%s'", line);
601 return -1;
602 }
603
604
605 /*
606 * We count spawned/reaped separately, just to avoid any
607 * races when updating them from signals. The SIGCHLD handler
608 * will only update children_reaped, and the fork logic will
609 * only update children_spawned.
610 *
611 * MAX_CHILDREN should be a power-of-two to make the modulus
612 * operation cheap. It should also be at least twice
613 * the maximum number of connections we will ever allow.
614 */
615 #define MAX_CHILDREN 128
616
617 static int max_connections = 25;
618
619 /* These are updated by the signal handler */
620 static volatile unsigned int children_reaped;
621 static pid_t dead_child[MAX_CHILDREN];
622
623 /* These are updated by the main loop */
624 static unsigned int children_spawned;
625 static unsigned int children_deleted;
626
627 static struct child {
628 pid_t pid;
629 int addrlen;
630 struct sockaddr_storage address;
631 } live_child[MAX_CHILDREN];
632
633 static void add_child(int idx, pid_t pid, struct sockaddr *addr, int addrlen)
634 {
635 live_child[idx].pid = pid;
636 live_child[idx].addrlen = addrlen;
637 memcpy(&live_child[idx].address, addr, addrlen);
638 }
639
640 /*
641 * Walk from "deleted" to "spawned", and remove child "pid".
642 *
643 * We move everything up by one, since the new "deleted" will
644 * be one higher.
645 */
646 static void remove_child(pid_t pid, unsigned deleted, unsigned spawned)
647 {
648 struct child n;
649
650 deleted %= MAX_CHILDREN;
651 spawned %= MAX_CHILDREN;
652 if (live_child[deleted].pid == pid) {
653 live_child[deleted].pid = -1;
654 return;
655 }
656 n = live_child[deleted];
657 for (;;) {
658 struct child m;
659 deleted = (deleted + 1) % MAX_CHILDREN;
660 if (deleted == spawned)
661 die("could not find dead child %d\n", pid);
662 m = live_child[deleted];
663 live_child[deleted] = n;
664 if (m.pid == pid)
665 return;
666 n = m;
667 }
668 }
669
670 /*
671 * This gets called if the number of connections grows
672 * past "max_connections".
673 *
674 * We _should_ start off by searching for connections
675 * from the same IP, and if there is some address wth
676 * multiple connections, we should kill that first.
677 *
678 * As it is, we just "randomly" kill 25% of the connections,
679 * and our pseudo-random generator sucks too. I have no
680 * shame.
681 *
682 * Really, this is just a place-holder for a _real_ algorithm.
683 */
684 static void kill_some_children(int signo, unsigned start, unsigned stop)
685 {
686 start %= MAX_CHILDREN;
687 stop %= MAX_CHILDREN;
688 while (start != stop) {
689 if (!(start & 3))
690 kill(live_child[start].pid, signo);
691 start = (start + 1) % MAX_CHILDREN;
692 }
693 }
694
695 static void check_max_connections(void)
696 {
697 for (;;) {
698 int active;
699 unsigned spawned, reaped, deleted;
700
701 spawned = children_spawned;
702 reaped = children_reaped;
703 deleted = children_deleted;
704
705 while (deleted < reaped) {
706 pid_t pid = dead_child[deleted % MAX_CHILDREN];
707 remove_child(pid, deleted, spawned);
708 deleted++;
709 }
710 children_deleted = deleted;
711
712 active = spawned - deleted;
713 if (active <= max_connections)
714 break;
715
716 /* Kill some unstarted connections with SIGTERM */
717 kill_some_children(SIGTERM, deleted, spawned);
718 if (active <= max_connections << 1)
719 break;
720
721 /* If the SIGTERM thing isn't helping use SIGKILL */
722 kill_some_children(SIGKILL, deleted, spawned);
723 sleep(1);
724 }
725 }
726
727 static void handle(int incoming, struct sockaddr *addr, int addrlen)
728 {
729 pid_t pid = fork();
730
731 if (pid) {
732 unsigned idx;
733
734 close(incoming);
735 if (pid < 0)
736 return;
737
738 idx = children_spawned % MAX_CHILDREN;
739 children_spawned++;
740 add_child(idx, pid, addr, addrlen);
741
742 check_max_connections();
743 return;
744 }
745
746 dup2(incoming, 0);
747 dup2(incoming, 1);
748 close(incoming);
749
750 exit(execute(addr));
751 }
752
753 static void child_handler(int signo)
754 {
755 for (;;) {
756 int status;
757 pid_t pid = waitpid(-1, &status, WNOHANG);
758
759 if (pid > 0) {
760 unsigned reaped = children_reaped;
761 dead_child[reaped % MAX_CHILDREN] = pid;
762 children_reaped = reaped + 1;
763 /* XXX: Custom logging, since we don't wanna getpid() */
764 if (verbose) {
765 const char *dead = "";
766 if (!WIFEXITED(status) || WEXITSTATUS(status) > 0)
767 dead = " (with error)";
768 if (log_syslog)
769 syslog(LOG_INFO, "[%d] Disconnected%s", pid, dead);
770 else
771 fprintf(stderr, "[%d] Disconnected%s\n", pid, dead);
772 }
773 continue;
774 }
775 break;
776 }
777 }
778
779 static int set_reuse_addr(int sockfd)
780 {
781 int on = 1;
782
783 if (!reuseaddr)
784 return 0;
785 return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
786 &on, sizeof(on));
787 }
788
789 #ifndef NO_IPV6
790
791 static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
792 {
793 int socknum = 0, *socklist = NULL;
794 int maxfd = -1;
795 char pbuf[NI_MAXSERV];
796 struct addrinfo hints, *ai0, *ai;
797 int gai;
798 long flags;
799
800 sprintf(pbuf, "%d", listen_port);
801 memset(&hints, 0, sizeof(hints));
802 hints.ai_family = AF_UNSPEC;
803 hints.ai_socktype = SOCK_STREAM;
804 hints.ai_protocol = IPPROTO_TCP;
805 hints.ai_flags = AI_PASSIVE;
806
807 gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
808 if (gai)
809 die("getaddrinfo() failed: %s\n", gai_strerror(gai));
810
811 for (ai = ai0; ai; ai = ai->ai_next) {
812 int sockfd;
813
814 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
815 if (sockfd < 0)
816 continue;
817 if (sockfd >= FD_SETSIZE) {
818 error("too large socket descriptor.");
819 close(sockfd);
820 continue;
821 }
822
823 #ifdef IPV6_V6ONLY
824 if (ai->ai_family == AF_INET6) {
825 int on = 1;
826 setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
827 &on, sizeof(on));
828 /* Note: error is not fatal */
829 }
830 #endif
831
832 if (set_reuse_addr(sockfd)) {
833 close(sockfd);
834 continue;
835 }
836
837 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
838 close(sockfd);
839 continue; /* not fatal */
840 }
841 if (listen(sockfd, 5) < 0) {
842 close(sockfd);
843 continue; /* not fatal */
844 }
845
846 flags = fcntl(sockfd, F_GETFD, 0);
847 if (flags >= 0)
848 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
849
850 socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
851 socklist[socknum++] = sockfd;
852
853 if (maxfd < sockfd)
854 maxfd = sockfd;
855 }
856
857 freeaddrinfo(ai0);
858
859 *socklist_p = socklist;
860 return socknum;
861 }
862
863 #else /* NO_IPV6 */
864
865 static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
866 {
867 struct sockaddr_in sin;
868 int sockfd;
869 long flags;
870
871 memset(&sin, 0, sizeof sin);
872 sin.sin_family = AF_INET;
873 sin.sin_port = htons(listen_port);
874
875 if (listen_addr) {
876 /* Well, host better be an IP address here. */
877 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
878 return 0;
879 } else {
880 sin.sin_addr.s_addr = htonl(INADDR_ANY);
881 }
882
883 sockfd = socket(AF_INET, SOCK_STREAM, 0);
884 if (sockfd < 0)
885 return 0;
886
887 if (set_reuse_addr(sockfd)) {
888 close(sockfd);
889 return 0;
890 }
891
892 if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
893 close(sockfd);
894 return 0;
895 }
896
897 if (listen(sockfd, 5) < 0) {
898 close(sockfd);
899 return 0;
900 }
901
902 flags = fcntl(sockfd, F_GETFD, 0);
903 if (flags >= 0)
904 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
905
906 *socklist_p = xmalloc(sizeof(int));
907 **socklist_p = sockfd;
908 return 1;
909 }
910
911 #endif
912
913 static int service_loop(int socknum, int *socklist)
914 {
915 struct pollfd *pfd;
916 int i;
917
918 pfd = xcalloc(socknum, sizeof(struct pollfd));
919
920 for (i = 0; i < socknum; i++) {
921 pfd[i].fd = socklist[i];
922 pfd[i].events = POLLIN;
923 }
924
925 signal(SIGCHLD, child_handler);
926
927 for (;;) {
928 int i;
929
930 if (poll(pfd, socknum, -1) < 0) {
931 if (errno != EINTR) {
932 error("poll failed, resuming: %s",
933 strerror(errno));
934 sleep(1);
935 }
936 continue;
937 }
938
939 for (i = 0; i < socknum; i++) {
940 if (pfd[i].revents & POLLIN) {
941 struct sockaddr_storage ss;
942 unsigned int sslen = sizeof(ss);
943 int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
944 if (incoming < 0) {
945 switch (errno) {
946 case EAGAIN:
947 case EINTR:
948 case ECONNABORTED:
949 continue;
950 default:
951 die("accept returned %s", strerror(errno));
952 }
953 }
954 handle(incoming, (struct sockaddr *)&ss, sslen);
955 }
956 }
957 }
958 }
959
960 /* if any standard file descriptor is missing open it to /dev/null */
961 static void sanitize_stdfds(void)
962 {
963 int fd = open("/dev/null", O_RDWR, 0);
964 while (fd != -1 && fd < 2)
965 fd = dup(fd);
966 if (fd == -1)
967 die("open /dev/null or dup failed: %s", strerror(errno));
968 if (fd > 2)
969 close(fd);
970 }
971
972 static void daemonize(void)
973 {
974 switch (fork()) {
975 case 0:
976 break;
977 case -1:
978 die("fork failed: %s", strerror(errno));
979 default:
980 exit(0);
981 }
982 if (setsid() == -1)
983 die("setsid failed: %s", strerror(errno));
984 close(0);
985 close(1);
986 close(2);
987 sanitize_stdfds();
988 }
989
990 static void store_pid(const char *path)
991 {
992 FILE *f = fopen(path, "w");
993 if (!f)
994 die("cannot open pid file %s: %s", path, strerror(errno));
995 if (fprintf(f, "%d\n", getpid()) < 0 || fclose(f) != 0)
996 die("failed to write pid file %s: %s", path, strerror(errno));
997 }
998
999 static int serve(char *listen_addr, int listen_port, struct passwd *pass, gid_t gid)
1000 {
1001 int socknum, *socklist;
1002
1003 socknum = socksetup(listen_addr, listen_port, &socklist);
1004 if (socknum == 0)
1005 die("unable to allocate any listen sockets on host %s port %u",
1006 listen_addr, listen_port);
1007
1008 if (pass && gid &&
1009 (initgroups(pass->pw_name, gid) || setgid (gid) ||
1010 setuid(pass->pw_uid)))
1011 die("cannot drop privileges");
1012
1013 return service_loop(socknum, socklist);
1014 }
1015
1016 int main(int argc, char **argv)
1017 {
1018 int listen_port = 0;
1019 char *listen_addr = NULL;
1020 int inetd_mode = 0;
1021 const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1022 int detach = 0;
1023 struct passwd *pass = NULL;
1024 struct group *group;
1025 gid_t gid = 0;
1026 int i;
1027
1028 /* Without this we cannot rely on waitpid() to tell
1029 * what happened to our children.
1030 */
1031 signal(SIGCHLD, SIG_DFL);
1032
1033 for (i = 1; i < argc; i++) {
1034 char *arg = argv[i];
1035
1036 if (!prefixcmp(arg, "--listen=")) {
1037 char *p = arg + 9;
1038 char *ph = listen_addr = xmalloc(strlen(arg + 9) + 1);
1039 while (*p)
1040 *ph++ = tolower(*p++);
1041 *ph = 0;
1042 continue;
1043 }
1044 if (!prefixcmp(arg, "--port=")) {
1045 char *end;
1046 unsigned long n;
1047 n = strtoul(arg+7, &end, 0);
1048 if (arg[7] && !*end) {
1049 listen_port = n;
1050 continue;
1051 }
1052 }
1053 if (!strcmp(arg, "--inetd")) {
1054 inetd_mode = 1;
1055 log_syslog = 1;
1056 continue;
1057 }
1058 if (!strcmp(arg, "--verbose")) {
1059 verbose = 1;
1060 continue;
1061 }
1062 if (!strcmp(arg, "--syslog")) {
1063 log_syslog = 1;
1064 continue;
1065 }
1066 if (!strcmp(arg, "--export-all")) {
1067 export_all_trees = 1;
1068 continue;
1069 }
1070 if (!prefixcmp(arg, "--timeout=")) {
1071 timeout = atoi(arg+10);
1072 continue;
1073 }
1074 if (!prefixcmp(arg, "--init-timeout=")) {
1075 init_timeout = atoi(arg+15);
1076 continue;
1077 }
1078 if (!strcmp(arg, "--strict-paths")) {
1079 strict_paths = 1;
1080 continue;
1081 }
1082 if (!prefixcmp(arg, "--base-path=")) {
1083 base_path = arg+12;
1084 continue;
1085 }
1086 if (!strcmp(arg, "--base-path-relaxed")) {
1087 base_path_relaxed = 1;
1088 continue;
1089 }
1090 if (!prefixcmp(arg, "--interpolated-path=")) {
1091 interpolated_path = arg+20;
1092 continue;
1093 }
1094 if (!strcmp(arg, "--reuseaddr")) {
1095 reuseaddr = 1;
1096 continue;
1097 }
1098 if (!strcmp(arg, "--user-path")) {
1099 user_path = "";
1100 continue;
1101 }
1102 if (!prefixcmp(arg, "--user-path=")) {
1103 user_path = arg + 12;
1104 continue;
1105 }
1106 if (!prefixcmp(arg, "--pid-file=")) {
1107 pid_file = arg + 11;
1108 continue;
1109 }
1110 if (!strcmp(arg, "--detach")) {
1111 detach = 1;
1112 log_syslog = 1;
1113 continue;
1114 }
1115 if (!prefixcmp(arg, "--user=")) {
1116 user_name = arg + 7;
1117 continue;
1118 }
1119 if (!prefixcmp(arg, "--group=")) {
1120 group_name = arg + 8;
1121 continue;
1122 }
1123 if (!prefixcmp(arg, "--enable=")) {
1124 enable_service(arg + 9, 1);
1125 continue;
1126 }
1127 if (!prefixcmp(arg, "--disable=")) {
1128 enable_service(arg + 10, 0);
1129 continue;
1130 }
1131 if (!prefixcmp(arg, "--allow-override=")) {
1132 make_service_overridable(arg + 17, 1);
1133 continue;
1134 }
1135 if (!prefixcmp(arg, "--forbid-override=")) {
1136 make_service_overridable(arg + 18, 0);
1137 continue;
1138 }
1139 if (!strcmp(arg, "--")) {
1140 ok_paths = &argv[i+1];
1141 break;
1142 } else if (arg[0] != '-') {
1143 ok_paths = &argv[i];
1144 break;
1145 }
1146
1147 usage(daemon_usage);
1148 }
1149
1150 if (inetd_mode && (group_name || user_name))
1151 die("--user and --group are incompatible with --inetd");
1152
1153 if (inetd_mode && (listen_port || listen_addr))
1154 die("--listen= and --port= are incompatible with --inetd");
1155 else if (listen_port == 0)
1156 listen_port = DEFAULT_GIT_PORT;
1157
1158 if (group_name && !user_name)
1159 die("--group supplied without --user");
1160
1161 if (user_name) {
1162 pass = getpwnam(user_name);
1163 if (!pass)
1164 die("user not found - %s", user_name);
1165
1166 if (!group_name)
1167 gid = pass->pw_gid;
1168 else {
1169 group = getgrnam(group_name);
1170 if (!group)
1171 die("group not found - %s", group_name);
1172
1173 gid = group->gr_gid;
1174 }
1175 }
1176
1177 if (log_syslog) {
1178 openlog("git-daemon", 0, LOG_DAEMON);
1179 set_die_routine(daemon_die);
1180 }
1181
1182 if (strict_paths && (!ok_paths || !*ok_paths))
1183 die("option --strict-paths requires a whitelist");
1184
1185 if (inetd_mode) {
1186 struct sockaddr_storage ss;
1187 struct sockaddr *peer = (struct sockaddr *)&ss;
1188 socklen_t slen = sizeof(ss);
1189
1190 freopen("/dev/null", "w", stderr);
1191
1192 if (getpeername(0, peer, &slen))
1193 peer = NULL;
1194
1195 return execute(peer);
1196 }
1197
1198 if (detach)
1199 daemonize();
1200 else
1201 sanitize_stdfds();
1202
1203 if (pid_file)
1204 store_pid(pid_file);
1205
1206 return serve(listen_addr, listen_port, pass, gid);
1207 }