Update release notes for 1.6.0.3
[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 static int child_handler_pipe[2];
20
21 static const char daemon_usage[] =
22 "git daemon [--verbose] [--syslog] [--export-all]\n"
23 " [--timeout=n] [--init-timeout=n] [--strict-paths]\n"
24 " [--base-path=path] [--base-path-relaxed]\n"
25 " [--user-path | --user-path=path]\n"
26 " [--interpolated-path=path]\n"
27 " [--reuseaddr] [--detach] [--pid-file=file]\n"
28 " [--[enable|disable|allow-override|forbid-override]=service]\n"
29 " [--inetd | [--listen=host_or_ipaddr] [--port=n]\n"
30 " [--user=user [--group=group]]\n"
31 " [directory...]";
32
33 /* List of acceptable pathname prefixes */
34 static char **ok_paths;
35 static int strict_paths;
36
37 /* If this is set, git-daemon-export-ok is not required */
38 static int export_all_trees;
39
40 /* Take all paths relative to this one if non-NULL */
41 static char *base_path;
42 static char *interpolated_path;
43 static int base_path_relaxed;
44
45 /* Flag indicating client sent extra args. */
46 static int saw_extended_args;
47
48 /* If defined, ~user notation is allowed and the string is inserted
49 * after ~user/. E.g. a request to git://host/~alice/frotz would
50 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
51 */
52 static const char *user_path;
53
54 /* Timeout, and initial timeout */
55 static unsigned int timeout;
56 static unsigned int init_timeout;
57
58 /*
59 * Static table for now. Ugh.
60 * Feel free to make dynamic as needed.
61 */
62 #define INTERP_SLOT_HOST (0)
63 #define INTERP_SLOT_CANON_HOST (1)
64 #define INTERP_SLOT_IP (2)
65 #define INTERP_SLOT_PORT (3)
66 #define INTERP_SLOT_DIR (4)
67 #define INTERP_SLOT_PERCENT (5)
68
69 static struct interp interp_table[] = {
70 { "%H", 0},
71 { "%CH", 0},
72 { "%IP", 0},
73 { "%P", 0},
74 { "%D", 0},
75 { "%%", 0},
76 };
77
78
79 static void logreport(int priority, const char *err, va_list params)
80 {
81 /* We should do a single write so that it is atomic and output
82 * of several processes do not get intermingled. */
83 char buf[1024];
84 int buflen;
85 int maxlen, msglen;
86
87 /* sizeof(buf) should be big enough for "[pid] \n" */
88 buflen = snprintf(buf, sizeof(buf), "[%ld] ", (long) getpid());
89
90 maxlen = sizeof(buf) - buflen - 1; /* -1 for our own LF */
91 msglen = vsnprintf(buf + buflen, maxlen, err, params);
92
93 if (log_syslog) {
94 syslog(priority, "%s", buf);
95 return;
96 }
97
98 /* maxlen counted our own LF but also counts space given to
99 * vsnprintf for the terminating NUL. We want to make sure that
100 * we have space for our own LF and NUL after the "meat" of the
101 * message, so truncate it at maxlen - 1.
102 */
103 if (msglen > maxlen - 1)
104 msglen = maxlen - 1;
105 else if (msglen < 0)
106 msglen = 0; /* Protect against weird return values. */
107 buflen += msglen;
108
109 buf[buflen++] = '\n';
110 buf[buflen] = '\0';
111
112 write_in_full(2, buf, buflen);
113 }
114
115 static void logerror(const char *err, ...)
116 {
117 va_list params;
118 va_start(params, err);
119 logreport(LOG_ERR, err, params);
120 va_end(params);
121 }
122
123 static void loginfo(const char *err, ...)
124 {
125 va_list params;
126 if (!verbose)
127 return;
128 va_start(params, err);
129 logreport(LOG_INFO, err, params);
130 va_end(params);
131 }
132
133 static void NORETURN daemon_die(const char *err, va_list params)
134 {
135 logreport(LOG_ERR, err, params);
136 exit(1);
137 }
138
139 static int avoid_alias(char *p)
140 {
141 int sl, ndot;
142
143 /*
144 * This resurrects the belts and suspenders paranoia check by HPA
145 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
146 * does not do getcwd() based path canonicalizations.
147 *
148 * sl becomes true immediately after seeing '/' and continues to
149 * be true as long as dots continue after that without intervening
150 * non-dot character.
151 */
152 if (!p || (*p != '/' && *p != '~'))
153 return -1;
154 sl = 1; ndot = 0;
155 p++;
156
157 while (1) {
158 char ch = *p++;
159 if (sl) {
160 if (ch == '.')
161 ndot++;
162 else if (ch == '/') {
163 if (ndot < 3)
164 /* reject //, /./ and /../ */
165 return -1;
166 ndot = 0;
167 }
168 else if (ch == 0) {
169 if (0 < ndot && ndot < 3)
170 /* reject /.$ and /..$ */
171 return -1;
172 return 0;
173 }
174 else
175 sl = ndot = 0;
176 }
177 else if (ch == 0)
178 return 0;
179 else if (ch == '/') {
180 sl = 1;
181 ndot = 0;
182 }
183 }
184 }
185
186 static char *path_ok(struct interp *itable)
187 {
188 static char rpath[PATH_MAX];
189 static char interp_path[PATH_MAX];
190 int retried_path = 0;
191 char *path;
192 char *dir;
193
194 dir = itable[INTERP_SLOT_DIR].value;
195
196 if (avoid_alias(dir)) {
197 logerror("'%s': aliased", dir);
198 return NULL;
199 }
200
201 if (*dir == '~') {
202 if (!user_path) {
203 logerror("'%s': User-path not allowed", dir);
204 return NULL;
205 }
206 if (*user_path) {
207 /* Got either "~alice" or "~alice/foo";
208 * rewrite them to "~alice/%s" or
209 * "~alice/%s/foo".
210 */
211 int namlen, restlen = strlen(dir);
212 char *slash = strchr(dir, '/');
213 if (!slash)
214 slash = dir + restlen;
215 namlen = slash - dir;
216 restlen -= namlen;
217 loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
218 snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
219 namlen, dir, user_path, restlen, slash);
220 dir = rpath;
221 }
222 }
223 else if (interpolated_path && saw_extended_args) {
224 if (*dir != '/') {
225 /* Allow only absolute */
226 logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
227 return NULL;
228 }
229
230 interpolate(interp_path, PATH_MAX, interpolated_path,
231 interp_table, ARRAY_SIZE(interp_table));
232 loginfo("Interpolated dir '%s'", interp_path);
233
234 dir = interp_path;
235 }
236 else if (base_path) {
237 if (*dir != '/') {
238 /* Allow only absolute */
239 logerror("'%s': Non-absolute path denied (base-path active)", dir);
240 return NULL;
241 }
242 snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
243 dir = rpath;
244 }
245
246 do {
247 path = enter_repo(dir, strict_paths);
248 if (path)
249 break;
250
251 /*
252 * if we fail and base_path_relaxed is enabled, try without
253 * prefixing the base path
254 */
255 if (base_path && base_path_relaxed && !retried_path) {
256 dir = itable[INTERP_SLOT_DIR].value;
257 retried_path = 1;
258 continue;
259 }
260 break;
261 } while (1);
262
263 if (!path) {
264 logerror("'%s': unable to chdir or not a git archive", dir);
265 return NULL;
266 }
267
268 if ( ok_paths && *ok_paths ) {
269 char **pp;
270 int pathlen = strlen(path);
271
272 /* The validation is done on the paths after enter_repo
273 * appends optional {.git,.git/.git} and friends, but
274 * it does not use getcwd(). So if your /pub is
275 * a symlink to /mnt/pub, you can whitelist /pub and
276 * do not have to say /mnt/pub.
277 * Do not say /pub/.
278 */
279 for ( pp = ok_paths ; *pp ; pp++ ) {
280 int len = strlen(*pp);
281 if (len <= pathlen &&
282 !memcmp(*pp, path, len) &&
283 (path[len] == '\0' ||
284 (!strict_paths && path[len] == '/')))
285 return path;
286 }
287 }
288 else {
289 /* be backwards compatible */
290 if (!strict_paths)
291 return path;
292 }
293
294 logerror("'%s': not in whitelist", path);
295 return NULL; /* Fallthrough. Deny by default */
296 }
297
298 typedef int (*daemon_service_fn)(void);
299 struct daemon_service {
300 const char *name;
301 const char *config_name;
302 daemon_service_fn fn;
303 int enabled;
304 int overridable;
305 };
306
307 static struct daemon_service *service_looking_at;
308 static int service_enabled;
309
310 static int git_daemon_config(const char *var, const char *value, void *cb)
311 {
312 if (!prefixcmp(var, "daemon.") &&
313 !strcmp(var + 7, service_looking_at->config_name)) {
314 service_enabled = git_config_bool(var, value);
315 return 0;
316 }
317
318 /* we are not interested in parsing any other configuration here */
319 return 0;
320 }
321
322 static int run_service(struct interp *itable, struct daemon_service *service)
323 {
324 const char *path;
325 int enabled = service->enabled;
326
327 loginfo("Request %s for '%s'",
328 service->name,
329 itable[INTERP_SLOT_DIR].value);
330
331 if (!enabled && !service->overridable) {
332 logerror("'%s': service not enabled.", service->name);
333 errno = EACCES;
334 return -1;
335 }
336
337 if (!(path = path_ok(itable)))
338 return -1;
339
340 /*
341 * Security on the cheap.
342 *
343 * We want a readable HEAD, usable "objects" directory, and
344 * a "git-daemon-export-ok" flag that says that the other side
345 * is ok with us doing this.
346 *
347 * path_ok() uses enter_repo() and does whitelist checking.
348 * We only need to make sure the repository is exported.
349 */
350
351 if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
352 logerror("'%s': repository not exported.", path);
353 errno = EACCES;
354 return -1;
355 }
356
357 if (service->overridable) {
358 service_looking_at = service;
359 service_enabled = -1;
360 git_config(git_daemon_config, NULL);
361 if (0 <= service_enabled)
362 enabled = service_enabled;
363 }
364 if (!enabled) {
365 logerror("'%s': service not enabled for '%s'",
366 service->name, path);
367 errno = EACCES;
368 return -1;
369 }
370
371 /*
372 * We'll ignore SIGTERM from now on, we have a
373 * good client.
374 */
375 signal(SIGTERM, SIG_IGN);
376
377 return service->fn();
378 }
379
380 static int upload_pack(void)
381 {
382 /* Timeout as string */
383 char timeout_buf[64];
384
385 snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
386
387 /* git-upload-pack only ever reads stuff, so this is safe */
388 execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL);
389 return -1;
390 }
391
392 static int upload_archive(void)
393 {
394 execl_git_cmd("upload-archive", ".", NULL);
395 return -1;
396 }
397
398 static int receive_pack(void)
399 {
400 execl_git_cmd("receive-pack", ".", NULL);
401 return -1;
402 }
403
404 static struct daemon_service daemon_service[] = {
405 { "upload-archive", "uploadarch", upload_archive, 0, 1 },
406 { "upload-pack", "uploadpack", upload_pack, 1, 1 },
407 { "receive-pack", "receivepack", receive_pack, 0, 1 },
408 };
409
410 static void enable_service(const char *name, int ena)
411 {
412 int i;
413 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
414 if (!strcmp(daemon_service[i].name, name)) {
415 daemon_service[i].enabled = ena;
416 return;
417 }
418 }
419 die("No such service %s", name);
420 }
421
422 static void make_service_overridable(const char *name, int ena)
423 {
424 int i;
425 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
426 if (!strcmp(daemon_service[i].name, name)) {
427 daemon_service[i].overridable = ena;
428 return;
429 }
430 }
431 die("No such service %s", name);
432 }
433
434 /*
435 * Separate the "extra args" information as supplied by the client connection.
436 * Any resulting data is squirreled away in the given interpolation table.
437 */
438 static void parse_extra_args(struct interp *table, char *extra_args, int buflen)
439 {
440 char *val;
441 int vallen;
442 char *end = extra_args + buflen;
443
444 while (extra_args < end && *extra_args) {
445 saw_extended_args = 1;
446 if (strncasecmp("host=", extra_args, 5) == 0) {
447 val = extra_args + 5;
448 vallen = strlen(val) + 1;
449 if (*val) {
450 /* Split <host>:<port> at colon. */
451 char *host = val;
452 char *port = strrchr(host, ':');
453 if (port) {
454 *port = 0;
455 port++;
456 interp_set_entry(table, INTERP_SLOT_PORT, port);
457 }
458 interp_set_entry(table, INTERP_SLOT_HOST, host);
459 }
460
461 /* On to the next one */
462 extra_args = val + vallen;
463 }
464 }
465 }
466
467 static void fill_in_extra_table_entries(struct interp *itable)
468 {
469 char *hp;
470
471 /*
472 * Replace literal host with lowercase-ized hostname.
473 */
474 hp = interp_table[INTERP_SLOT_HOST].value;
475 if (!hp)
476 return;
477 for ( ; *hp; hp++)
478 *hp = tolower(*hp);
479
480 /*
481 * Locate canonical hostname and its IP address.
482 */
483 #ifndef NO_IPV6
484 {
485 struct addrinfo hints;
486 struct addrinfo *ai, *ai0;
487 int gai;
488 static char addrbuf[HOST_NAME_MAX + 1];
489
490 memset(&hints, 0, sizeof(hints));
491 hints.ai_flags = AI_CANONNAME;
492
493 gai = getaddrinfo(interp_table[INTERP_SLOT_HOST].value, 0, &hints, &ai0);
494 if (!gai) {
495 for (ai = ai0; ai; ai = ai->ai_next) {
496 struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
497
498 inet_ntop(AF_INET, &sin_addr->sin_addr,
499 addrbuf, sizeof(addrbuf));
500 interp_set_entry(interp_table,
501 INTERP_SLOT_CANON_HOST, ai->ai_canonname);
502 interp_set_entry(interp_table,
503 INTERP_SLOT_IP, addrbuf);
504 break;
505 }
506 freeaddrinfo(ai0);
507 }
508 }
509 #else
510 {
511 struct hostent *hent;
512 struct sockaddr_in sa;
513 char **ap;
514 static char addrbuf[HOST_NAME_MAX + 1];
515
516 hent = gethostbyname(interp_table[INTERP_SLOT_HOST].value);
517
518 ap = hent->h_addr_list;
519 memset(&sa, 0, sizeof sa);
520 sa.sin_family = hent->h_addrtype;
521 sa.sin_port = htons(0);
522 memcpy(&sa.sin_addr, *ap, hent->h_length);
523
524 inet_ntop(hent->h_addrtype, &sa.sin_addr,
525 addrbuf, sizeof(addrbuf));
526
527 interp_set_entry(interp_table, INTERP_SLOT_CANON_HOST, hent->h_name);
528 interp_set_entry(interp_table, INTERP_SLOT_IP, addrbuf);
529 }
530 #endif
531 }
532
533
534 static int execute(struct sockaddr *addr)
535 {
536 static char line[1000];
537 int pktlen, len, i;
538
539 if (addr) {
540 char addrbuf[256] = "";
541 int port = -1;
542
543 if (addr->sa_family == AF_INET) {
544 struct sockaddr_in *sin_addr = (void *) addr;
545 inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
546 port = ntohs(sin_addr->sin_port);
547 #ifndef NO_IPV6
548 } else if (addr && addr->sa_family == AF_INET6) {
549 struct sockaddr_in6 *sin6_addr = (void *) addr;
550
551 char *buf = addrbuf;
552 *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
553 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
554 strcat(buf, "]");
555
556 port = ntohs(sin6_addr->sin6_port);
557 #endif
558 }
559 loginfo("Connection from %s:%d", addrbuf, port);
560 }
561
562 alarm(init_timeout ? init_timeout : timeout);
563 pktlen = packet_read_line(0, line, sizeof(line));
564 alarm(0);
565
566 len = strlen(line);
567 if (pktlen != len)
568 loginfo("Extended attributes (%d bytes) exist <%.*s>",
569 (int) pktlen - len,
570 (int) pktlen - len, line + len + 1);
571 if (len && line[len-1] == '\n') {
572 line[--len] = 0;
573 pktlen--;
574 }
575
576 /*
577 * Initialize the path interpolation table for this connection.
578 */
579 interp_clear_table(interp_table, ARRAY_SIZE(interp_table));
580 interp_set_entry(interp_table, INTERP_SLOT_PERCENT, "%");
581
582 if (len != pktlen) {
583 parse_extra_args(interp_table, line + len + 1, pktlen - len - 1);
584 fill_in_extra_table_entries(interp_table);
585 }
586
587 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
588 struct daemon_service *s = &(daemon_service[i]);
589 int namelen = strlen(s->name);
590 if (!prefixcmp(line, "git-") &&
591 !strncmp(s->name, line + 4, namelen) &&
592 line[namelen + 4] == ' ') {
593 /*
594 * Note: The directory here is probably context sensitive,
595 * and might depend on the actual service being performed.
596 */
597 interp_set_entry(interp_table,
598 INTERP_SLOT_DIR, line + namelen + 5);
599 return run_service(interp_table, s);
600 }
601 }
602
603 logerror("Protocol error: '%s'", line);
604 return -1;
605 }
606
607
608 /*
609 * We count spawned/reaped separately, just to avoid any
610 * races when updating them from signals. The SIGCHLD handler
611 * will only update children_reaped, and the fork logic will
612 * only update children_spawned.
613 *
614 * MAX_CHILDREN should be a power-of-two to make the modulus
615 * operation cheap. It should also be at least twice
616 * the maximum number of connections we will ever allow.
617 */
618 #define MAX_CHILDREN 128
619
620 static int max_connections = 25;
621
622 /* These are updated by the signal handler */
623 static volatile unsigned int children_reaped;
624 static pid_t dead_child[MAX_CHILDREN];
625
626 /* These are updated by the main loop */
627 static unsigned int children_spawned;
628 static unsigned int children_deleted;
629
630 static struct child {
631 pid_t pid;
632 int addrlen;
633 struct sockaddr_storage address;
634 } live_child[MAX_CHILDREN];
635
636 static void add_child(int idx, pid_t pid, struct sockaddr *addr, int addrlen)
637 {
638 live_child[idx].pid = pid;
639 live_child[idx].addrlen = addrlen;
640 memcpy(&live_child[idx].address, addr, addrlen);
641 }
642
643 /*
644 * Walk from "deleted" to "spawned", and remove child "pid".
645 *
646 * We move everything up by one, since the new "deleted" will
647 * be one higher.
648 */
649 static void remove_child(pid_t pid, unsigned deleted, unsigned spawned)
650 {
651 struct child n;
652
653 deleted %= MAX_CHILDREN;
654 spawned %= MAX_CHILDREN;
655 if (live_child[deleted].pid == pid) {
656 live_child[deleted].pid = -1;
657 return;
658 }
659 n = live_child[deleted];
660 for (;;) {
661 struct child m;
662 deleted = (deleted + 1) % MAX_CHILDREN;
663 if (deleted == spawned)
664 die("could not find dead child %d\n", pid);
665 m = live_child[deleted];
666 live_child[deleted] = n;
667 if (m.pid == pid)
668 return;
669 n = m;
670 }
671 }
672
673 /*
674 * This gets called if the number of connections grows
675 * past "max_connections".
676 *
677 * We _should_ start off by searching for connections
678 * from the same IP, and if there is some address wth
679 * multiple connections, we should kill that first.
680 *
681 * As it is, we just "randomly" kill 25% of the connections,
682 * and our pseudo-random generator sucks too. I have no
683 * shame.
684 *
685 * Really, this is just a place-holder for a _real_ algorithm.
686 */
687 static void kill_some_children(int signo, unsigned start, unsigned stop)
688 {
689 start %= MAX_CHILDREN;
690 stop %= MAX_CHILDREN;
691 while (start != stop) {
692 if (!(start & 3))
693 kill(live_child[start].pid, signo);
694 start = (start + 1) % MAX_CHILDREN;
695 }
696 }
697
698 static void check_dead_children(void)
699 {
700 unsigned spawned, reaped, deleted;
701
702 spawned = children_spawned;
703 reaped = children_reaped;
704 deleted = children_deleted;
705
706 while (deleted < reaped) {
707 pid_t pid = dead_child[deleted % MAX_CHILDREN];
708 const char *dead = pid < 0 ? " (with error)" : "";
709
710 if (pid < 0)
711 pid = -pid;
712
713 /* XXX: Custom logging, since we don't wanna getpid() */
714 if (verbose) {
715 if (log_syslog)
716 syslog(LOG_INFO, "[%d] Disconnected%s",
717 pid, dead);
718 else
719 fprintf(stderr, "[%d] Disconnected%s\n",
720 pid, dead);
721 }
722 remove_child(pid, deleted, spawned);
723 deleted++;
724 }
725 children_deleted = deleted;
726 }
727
728 static void check_max_connections(void)
729 {
730 for (;;) {
731 int active;
732 unsigned spawned, deleted;
733
734 check_dead_children();
735
736 spawned = children_spawned;
737 deleted = children_deleted;
738
739 active = spawned - deleted;
740 if (active <= max_connections)
741 break;
742
743 /* Kill some unstarted connections with SIGTERM */
744 kill_some_children(SIGTERM, deleted, spawned);
745 if (active <= max_connections << 1)
746 break;
747
748 /* If the SIGTERM thing isn't helping use SIGKILL */
749 kill_some_children(SIGKILL, deleted, spawned);
750 sleep(1);
751 }
752 }
753
754 static void handle(int incoming, struct sockaddr *addr, int addrlen)
755 {
756 pid_t pid = fork();
757
758 if (pid) {
759 unsigned idx;
760
761 close(incoming);
762 if (pid < 0)
763 return;
764
765 idx = children_spawned % MAX_CHILDREN;
766 children_spawned++;
767 add_child(idx, pid, addr, addrlen);
768
769 check_max_connections();
770 return;
771 }
772
773 dup2(incoming, 0);
774 dup2(incoming, 1);
775 close(incoming);
776
777 exit(execute(addr));
778 }
779
780 static void child_handler(int signo)
781 {
782 for (;;) {
783 int status;
784 pid_t pid = waitpid(-1, &status, WNOHANG);
785
786 if (pid > 0) {
787 unsigned reaped = children_reaped;
788 if (!WIFEXITED(status) || WEXITSTATUS(status) > 0)
789 pid = -pid;
790 dead_child[reaped % MAX_CHILDREN] = pid;
791 children_reaped = reaped + 1;
792 write(child_handler_pipe[1], &status, 1);
793 continue;
794 }
795 break;
796 }
797 signal(SIGCHLD, child_handler);
798 }
799
800 static int set_reuse_addr(int sockfd)
801 {
802 int on = 1;
803
804 if (!reuseaddr)
805 return 0;
806 return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
807 &on, sizeof(on));
808 }
809
810 #ifndef NO_IPV6
811
812 static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
813 {
814 int socknum = 0, *socklist = NULL;
815 int maxfd = -1;
816 char pbuf[NI_MAXSERV];
817 struct addrinfo hints, *ai0, *ai;
818 int gai;
819 long flags;
820
821 sprintf(pbuf, "%d", listen_port);
822 memset(&hints, 0, sizeof(hints));
823 hints.ai_family = AF_UNSPEC;
824 hints.ai_socktype = SOCK_STREAM;
825 hints.ai_protocol = IPPROTO_TCP;
826 hints.ai_flags = AI_PASSIVE;
827
828 gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
829 if (gai)
830 die("getaddrinfo() failed: %s\n", gai_strerror(gai));
831
832 for (ai = ai0; ai; ai = ai->ai_next) {
833 int sockfd;
834
835 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
836 if (sockfd < 0)
837 continue;
838 if (sockfd >= FD_SETSIZE) {
839 error("too large socket descriptor.");
840 close(sockfd);
841 continue;
842 }
843
844 #ifdef IPV6_V6ONLY
845 if (ai->ai_family == AF_INET6) {
846 int on = 1;
847 setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
848 &on, sizeof(on));
849 /* Note: error is not fatal */
850 }
851 #endif
852
853 if (set_reuse_addr(sockfd)) {
854 close(sockfd);
855 continue;
856 }
857
858 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
859 close(sockfd);
860 continue; /* not fatal */
861 }
862 if (listen(sockfd, 5) < 0) {
863 close(sockfd);
864 continue; /* not fatal */
865 }
866
867 flags = fcntl(sockfd, F_GETFD, 0);
868 if (flags >= 0)
869 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
870
871 socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
872 socklist[socknum++] = sockfd;
873
874 if (maxfd < sockfd)
875 maxfd = sockfd;
876 }
877
878 freeaddrinfo(ai0);
879
880 *socklist_p = socklist;
881 return socknum;
882 }
883
884 #else /* NO_IPV6 */
885
886 static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
887 {
888 struct sockaddr_in sin;
889 int sockfd;
890 long flags;
891
892 memset(&sin, 0, sizeof sin);
893 sin.sin_family = AF_INET;
894 sin.sin_port = htons(listen_port);
895
896 if (listen_addr) {
897 /* Well, host better be an IP address here. */
898 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
899 return 0;
900 } else {
901 sin.sin_addr.s_addr = htonl(INADDR_ANY);
902 }
903
904 sockfd = socket(AF_INET, SOCK_STREAM, 0);
905 if (sockfd < 0)
906 return 0;
907
908 if (set_reuse_addr(sockfd)) {
909 close(sockfd);
910 return 0;
911 }
912
913 if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
914 close(sockfd);
915 return 0;
916 }
917
918 if (listen(sockfd, 5) < 0) {
919 close(sockfd);
920 return 0;
921 }
922
923 flags = fcntl(sockfd, F_GETFD, 0);
924 if (flags >= 0)
925 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
926
927 *socklist_p = xmalloc(sizeof(int));
928 **socklist_p = sockfd;
929 return 1;
930 }
931
932 #endif
933
934 static int service_loop(int socknum, int *socklist)
935 {
936 struct pollfd *pfd;
937 int i;
938
939 if (pipe(child_handler_pipe) < 0)
940 die ("Could not set up pipe for child handler");
941
942 pfd = xcalloc(socknum + 1, sizeof(struct pollfd));
943
944 for (i = 0; i < socknum; i++) {
945 pfd[i].fd = socklist[i];
946 pfd[i].events = POLLIN;
947 }
948 pfd[socknum].fd = child_handler_pipe[0];
949 pfd[socknum].events = POLLIN;
950
951 signal(SIGCHLD, child_handler);
952
953 for (;;) {
954 int i;
955
956 if (poll(pfd, socknum + 1, -1) < 0) {
957 if (errno != EINTR) {
958 error("poll failed, resuming: %s",
959 strerror(errno));
960 sleep(1);
961 }
962 continue;
963 }
964 if (pfd[socknum].revents & POLLIN) {
965 read(child_handler_pipe[0], &i, 1);
966 check_dead_children();
967 }
968
969 for (i = 0; i < socknum; i++) {
970 if (pfd[i].revents & POLLIN) {
971 struct sockaddr_storage ss;
972 unsigned int sslen = sizeof(ss);
973 int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
974 if (incoming < 0) {
975 switch (errno) {
976 case EAGAIN:
977 case EINTR:
978 case ECONNABORTED:
979 continue;
980 default:
981 die("accept returned %s", strerror(errno));
982 }
983 }
984 handle(incoming, (struct sockaddr *)&ss, sslen);
985 }
986 }
987 }
988 }
989
990 /* if any standard file descriptor is missing open it to /dev/null */
991 static void sanitize_stdfds(void)
992 {
993 int fd = open("/dev/null", O_RDWR, 0);
994 while (fd != -1 && fd < 2)
995 fd = dup(fd);
996 if (fd == -1)
997 die("open /dev/null or dup failed: %s", strerror(errno));
998 if (fd > 2)
999 close(fd);
1000 }
1001
1002 static void daemonize(void)
1003 {
1004 switch (fork()) {
1005 case 0:
1006 break;
1007 case -1:
1008 die("fork failed: %s", strerror(errno));
1009 default:
1010 exit(0);
1011 }
1012 if (setsid() == -1)
1013 die("setsid failed: %s", strerror(errno));
1014 close(0);
1015 close(1);
1016 close(2);
1017 sanitize_stdfds();
1018 }
1019
1020 static void store_pid(const char *path)
1021 {
1022 FILE *f = fopen(path, "w");
1023 if (!f)
1024 die("cannot open pid file %s: %s", path, strerror(errno));
1025 if (fprintf(f, "%d\n", getpid()) < 0 || fclose(f) != 0)
1026 die("failed to write pid file %s: %s", path, strerror(errno));
1027 }
1028
1029 static int serve(char *listen_addr, int listen_port, struct passwd *pass, gid_t gid)
1030 {
1031 int socknum, *socklist;
1032
1033 socknum = socksetup(listen_addr, listen_port, &socklist);
1034 if (socknum == 0)
1035 die("unable to allocate any listen sockets on host %s port %u",
1036 listen_addr, listen_port);
1037
1038 if (pass && gid &&
1039 (initgroups(pass->pw_name, gid) || setgid (gid) ||
1040 setuid(pass->pw_uid)))
1041 die("cannot drop privileges");
1042
1043 return service_loop(socknum, socklist);
1044 }
1045
1046 int main(int argc, char **argv)
1047 {
1048 int listen_port = 0;
1049 char *listen_addr = NULL;
1050 int inetd_mode = 0;
1051 const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1052 int detach = 0;
1053 struct passwd *pass = NULL;
1054 struct group *group;
1055 gid_t gid = 0;
1056 int i;
1057
1058 /* Without this we cannot rely on waitpid() to tell
1059 * what happened to our children.
1060 */
1061 signal(SIGCHLD, SIG_DFL);
1062
1063 for (i = 1; i < argc; i++) {
1064 char *arg = argv[i];
1065
1066 if (!prefixcmp(arg, "--listen=")) {
1067 char *p = arg + 9;
1068 char *ph = listen_addr = xmalloc(strlen(arg + 9) + 1);
1069 while (*p)
1070 *ph++ = tolower(*p++);
1071 *ph = 0;
1072 continue;
1073 }
1074 if (!prefixcmp(arg, "--port=")) {
1075 char *end;
1076 unsigned long n;
1077 n = strtoul(arg+7, &end, 0);
1078 if (arg[7] && !*end) {
1079 listen_port = n;
1080 continue;
1081 }
1082 }
1083 if (!strcmp(arg, "--inetd")) {
1084 inetd_mode = 1;
1085 log_syslog = 1;
1086 continue;
1087 }
1088 if (!strcmp(arg, "--verbose")) {
1089 verbose = 1;
1090 continue;
1091 }
1092 if (!strcmp(arg, "--syslog")) {
1093 log_syslog = 1;
1094 continue;
1095 }
1096 if (!strcmp(arg, "--export-all")) {
1097 export_all_trees = 1;
1098 continue;
1099 }
1100 if (!prefixcmp(arg, "--timeout=")) {
1101 timeout = atoi(arg+10);
1102 continue;
1103 }
1104 if (!prefixcmp(arg, "--init-timeout=")) {
1105 init_timeout = atoi(arg+15);
1106 continue;
1107 }
1108 if (!strcmp(arg, "--strict-paths")) {
1109 strict_paths = 1;
1110 continue;
1111 }
1112 if (!prefixcmp(arg, "--base-path=")) {
1113 base_path = arg+12;
1114 continue;
1115 }
1116 if (!strcmp(arg, "--base-path-relaxed")) {
1117 base_path_relaxed = 1;
1118 continue;
1119 }
1120 if (!prefixcmp(arg, "--interpolated-path=")) {
1121 interpolated_path = arg+20;
1122 continue;
1123 }
1124 if (!strcmp(arg, "--reuseaddr")) {
1125 reuseaddr = 1;
1126 continue;
1127 }
1128 if (!strcmp(arg, "--user-path")) {
1129 user_path = "";
1130 continue;
1131 }
1132 if (!prefixcmp(arg, "--user-path=")) {
1133 user_path = arg + 12;
1134 continue;
1135 }
1136 if (!prefixcmp(arg, "--pid-file=")) {
1137 pid_file = arg + 11;
1138 continue;
1139 }
1140 if (!strcmp(arg, "--detach")) {
1141 detach = 1;
1142 log_syslog = 1;
1143 continue;
1144 }
1145 if (!prefixcmp(arg, "--user=")) {
1146 user_name = arg + 7;
1147 continue;
1148 }
1149 if (!prefixcmp(arg, "--group=")) {
1150 group_name = arg + 8;
1151 continue;
1152 }
1153 if (!prefixcmp(arg, "--enable=")) {
1154 enable_service(arg + 9, 1);
1155 continue;
1156 }
1157 if (!prefixcmp(arg, "--disable=")) {
1158 enable_service(arg + 10, 0);
1159 continue;
1160 }
1161 if (!prefixcmp(arg, "--allow-override=")) {
1162 make_service_overridable(arg + 17, 1);
1163 continue;
1164 }
1165 if (!prefixcmp(arg, "--forbid-override=")) {
1166 make_service_overridable(arg + 18, 0);
1167 continue;
1168 }
1169 if (!strcmp(arg, "--")) {
1170 ok_paths = &argv[i+1];
1171 break;
1172 } else if (arg[0] != '-') {
1173 ok_paths = &argv[i];
1174 break;
1175 }
1176
1177 usage(daemon_usage);
1178 }
1179
1180 if (log_syslog) {
1181 openlog("git-daemon", 0, LOG_DAEMON);
1182 set_die_routine(daemon_die);
1183 }
1184
1185 if (inetd_mode && (group_name || user_name))
1186 die("--user and --group are incompatible with --inetd");
1187
1188 if (inetd_mode && (listen_port || listen_addr))
1189 die("--listen= and --port= are incompatible with --inetd");
1190 else if (listen_port == 0)
1191 listen_port = DEFAULT_GIT_PORT;
1192
1193 if (group_name && !user_name)
1194 die("--group supplied without --user");
1195
1196 if (user_name) {
1197 pass = getpwnam(user_name);
1198 if (!pass)
1199 die("user not found - %s", user_name);
1200
1201 if (!group_name)
1202 gid = pass->pw_gid;
1203 else {
1204 group = getgrnam(group_name);
1205 if (!group)
1206 die("group not found - %s", group_name);
1207
1208 gid = group->gr_gid;
1209 }
1210 }
1211
1212 if (strict_paths && (!ok_paths || !*ok_paths))
1213 die("option --strict-paths requires a whitelist");
1214
1215 if (base_path) {
1216 struct stat st;
1217
1218 if (stat(base_path, &st) || !S_ISDIR(st.st_mode))
1219 die("base-path '%s' does not exist or "
1220 "is not a directory", base_path);
1221 }
1222
1223 if (inetd_mode) {
1224 struct sockaddr_storage ss;
1225 struct sockaddr *peer = (struct sockaddr *)&ss;
1226 socklen_t slen = sizeof(ss);
1227
1228 freopen("/dev/null", "w", stderr);
1229
1230 if (getpeername(0, peer, &slen))
1231 peer = NULL;
1232
1233 return execute(peer);
1234 }
1235
1236 if (detach)
1237 daemonize();
1238 else
1239 sanitize_stdfds();
1240
1241 if (pid_file)
1242 store_pid(pid_file);
1243
1244 return serve(listen_addr, listen_port, pass, gid);
1245 }