daemon: fix error message after bind()
[git/git.git] / daemon.c
1 #include "cache.h"
2 #include "pkt-line.h"
3 #include "exec_cmd.h"
4 #include "run-command.h"
5 #include "strbuf.h"
6 #include "string-list.h"
7
8 #ifndef HOST_NAME_MAX
9 #define HOST_NAME_MAX 256
10 #endif
11
12 #ifdef NO_INITGROUPS
13 #define initgroups(x, y) (0) /* nothing */
14 #endif
15
16 static int log_syslog;
17 static int verbose;
18 static int reuseaddr;
19 static int informative_errors;
20
21 static const char daemon_usage[] =
22 "git daemon [--verbose] [--syslog] [--export-all]\n"
23 " [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n"
24 " [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
25 " [--user-path | --user-path=<path>]\n"
26 " [--interpolated-path=<path>]\n"
27 " [--reuseaddr] [--pid-file=<file>]\n"
28 " [--(enable|disable|allow-override|forbid-override)=<service>]\n"
29 " [--access-hook=<path>]\n"
30 " [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
31 " [--detach] [--user=<user> [--group=<group>]]\n"
32 " [<directory>...]";
33
34 /* List of acceptable pathname prefixes */
35 static char **ok_paths;
36 static int strict_paths;
37
38 /* If this is set, git-daemon-export-ok is not required */
39 static int export_all_trees;
40
41 /* Take all paths relative to this one if non-NULL */
42 static char *base_path;
43 static char *interpolated_path;
44 static int base_path_relaxed;
45
46 /* Flag indicating client sent extra args. */
47 static int saw_extended_args;
48
49 /* If defined, ~user notation is allowed and the string is inserted
50 * after ~user/. E.g. a request to git://host/~alice/frotz would
51 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
52 */
53 static const char *user_path;
54
55 /* Timeout, and initial timeout */
56 static unsigned int timeout;
57 static unsigned int init_timeout;
58
59 static char *hostname;
60 static char *canon_hostname;
61 static char *ip_address;
62 static char *tcp_port;
63
64 static void logreport(int priority, const char *err, va_list params)
65 {
66 if (log_syslog) {
67 char buf[1024];
68 vsnprintf(buf, sizeof(buf), err, params);
69 syslog(priority, "%s", buf);
70 } else {
71 /*
72 * Since stderr is set to buffered mode, the
73 * logging of different processes will not overlap
74 * unless they overflow the (rather big) buffers.
75 */
76 fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
77 vfprintf(stderr, err, params);
78 fputc('\n', stderr);
79 fflush(stderr);
80 }
81 }
82
83 __attribute__((format (printf, 1, 2)))
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 __attribute__((format (printf, 1, 2)))
93 static void loginfo(const char *err, ...)
94 {
95 va_list params;
96 if (!verbose)
97 return;
98 va_start(params, err);
99 logreport(LOG_INFO, err, params);
100 va_end(params);
101 }
102
103 static void NORETURN daemon_die(const char *err, va_list params)
104 {
105 logreport(LOG_ERR, err, params);
106 exit(1);
107 }
108
109 static const char *path_ok(char *directory)
110 {
111 static char rpath[PATH_MAX];
112 static char interp_path[PATH_MAX];
113 const char *path;
114 char *dir;
115
116 dir = directory;
117
118 if (daemon_avoid_alias(dir)) {
119 logerror("'%s': aliased", dir);
120 return NULL;
121 }
122
123 if (*dir == '~') {
124 if (!user_path) {
125 logerror("'%s': User-path not allowed", dir);
126 return NULL;
127 }
128 if (*user_path) {
129 /* Got either "~alice" or "~alice/foo";
130 * rewrite them to "~alice/%s" or
131 * "~alice/%s/foo".
132 */
133 int namlen, restlen = strlen(dir);
134 char *slash = strchr(dir, '/');
135 if (!slash)
136 slash = dir + restlen;
137 namlen = slash - dir;
138 restlen -= namlen;
139 loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
140 snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
141 namlen, dir, user_path, restlen, slash);
142 dir = rpath;
143 }
144 }
145 else if (interpolated_path && saw_extended_args) {
146 struct strbuf expanded_path = STRBUF_INIT;
147 struct strbuf_expand_dict_entry dict[6];
148
149 dict[0].placeholder = "H"; dict[0].value = hostname;
150 dict[1].placeholder = "CH"; dict[1].value = canon_hostname;
151 dict[2].placeholder = "IP"; dict[2].value = ip_address;
152 dict[3].placeholder = "P"; dict[3].value = tcp_port;
153 dict[4].placeholder = "D"; dict[4].value = directory;
154 dict[5].placeholder = NULL; dict[5].value = NULL;
155 if (*dir != '/') {
156 /* Allow only absolute */
157 logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
158 return NULL;
159 }
160
161 strbuf_expand(&expanded_path, interpolated_path,
162 strbuf_expand_dict_cb, &dict);
163 strlcpy(interp_path, expanded_path.buf, PATH_MAX);
164 strbuf_release(&expanded_path);
165 loginfo("Interpolated dir '%s'", interp_path);
166
167 dir = interp_path;
168 }
169 else if (base_path) {
170 if (*dir != '/') {
171 /* Allow only absolute */
172 logerror("'%s': Non-absolute path denied (base-path active)", dir);
173 return NULL;
174 }
175 snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
176 dir = rpath;
177 }
178
179 path = enter_repo(dir, strict_paths);
180 if (!path && base_path && base_path_relaxed) {
181 /*
182 * if we fail and base_path_relaxed is enabled, try without
183 * prefixing the base path
184 */
185 dir = directory;
186 path = enter_repo(dir, strict_paths);
187 }
188
189 if (!path) {
190 logerror("'%s' does not appear to be a git repository", dir);
191 return NULL;
192 }
193
194 if ( ok_paths && *ok_paths ) {
195 char **pp;
196 int pathlen = strlen(path);
197
198 /* The validation is done on the paths after enter_repo
199 * appends optional {.git,.git/.git} and friends, but
200 * it does not use getcwd(). So if your /pub is
201 * a symlink to /mnt/pub, you can whitelist /pub and
202 * do not have to say /mnt/pub.
203 * Do not say /pub/.
204 */
205 for ( pp = ok_paths ; *pp ; pp++ ) {
206 int len = strlen(*pp);
207 if (len <= pathlen &&
208 !memcmp(*pp, path, len) &&
209 (path[len] == '\0' ||
210 (!strict_paths && path[len] == '/')))
211 return path;
212 }
213 }
214 else {
215 /* be backwards compatible */
216 if (!strict_paths)
217 return path;
218 }
219
220 logerror("'%s': not in whitelist", path);
221 return NULL; /* Fallthrough. Deny by default */
222 }
223
224 typedef int (*daemon_service_fn)(void);
225 struct daemon_service {
226 const char *name;
227 const char *config_name;
228 daemon_service_fn fn;
229 int enabled;
230 int overridable;
231 };
232
233 static struct daemon_service *service_looking_at;
234 static int service_enabled;
235
236 static int git_daemon_config(const char *var, const char *value, void *cb)
237 {
238 if (!prefixcmp(var, "daemon.") &&
239 !strcmp(var + 7, service_looking_at->config_name)) {
240 service_enabled = git_config_bool(var, value);
241 return 0;
242 }
243
244 /* we are not interested in parsing any other configuration here */
245 return 0;
246 }
247
248 static int daemon_error(const char *dir, const char *msg)
249 {
250 if (!informative_errors)
251 msg = "access denied or repository not exported";
252 packet_write(1, "ERR %s: %s", msg, dir);
253 return -1;
254 }
255
256 static char *access_hook;
257
258 static int run_access_hook(struct daemon_service *service, const char *dir, const char *path)
259 {
260 struct child_process child;
261 struct strbuf buf = STRBUF_INIT;
262 const char *argv[8];
263 const char **arg = argv;
264 char *eol;
265 int seen_errors = 0;
266
267 #define STRARG(x) ((x) ? (x) : "")
268 *arg++ = access_hook;
269 *arg++ = service->name;
270 *arg++ = path;
271 *arg++ = STRARG(hostname);
272 *arg++ = STRARG(canon_hostname);
273 *arg++ = STRARG(ip_address);
274 *arg++ = STRARG(tcp_port);
275 *arg = NULL;
276 #undef STRARG
277
278 memset(&child, 0, sizeof(child));
279 child.use_shell = 1;
280 child.argv = argv;
281 child.no_stdin = 1;
282 child.no_stderr = 1;
283 child.out = -1;
284 if (start_command(&child)) {
285 logerror("daemon access hook '%s' failed to start",
286 access_hook);
287 goto error_return;
288 }
289 if (strbuf_read(&buf, child.out, 0) < 0) {
290 logerror("failed to read from pipe to daemon access hook '%s'",
291 access_hook);
292 strbuf_reset(&buf);
293 seen_errors = 1;
294 }
295 if (close(child.out) < 0) {
296 logerror("failed to close pipe to daemon access hook '%s'",
297 access_hook);
298 seen_errors = 1;
299 }
300 if (finish_command(&child))
301 seen_errors = 1;
302
303 if (!seen_errors) {
304 strbuf_release(&buf);
305 return 0;
306 }
307
308 error_return:
309 strbuf_ltrim(&buf);
310 if (!buf.len)
311 strbuf_addstr(&buf, "service rejected");
312 eol = strchr(buf.buf, '\n');
313 if (eol)
314 *eol = '\0';
315 errno = EACCES;
316 daemon_error(dir, buf.buf);
317 strbuf_release(&buf);
318 return -1;
319 }
320
321 static int run_service(char *dir, struct daemon_service *service)
322 {
323 const char *path;
324 int enabled = service->enabled;
325
326 loginfo("Request %s for '%s'", service->name, dir);
327
328 if (!enabled && !service->overridable) {
329 logerror("'%s': service not enabled.", service->name);
330 errno = EACCES;
331 return daemon_error(dir, "service not enabled");
332 }
333
334 if (!(path = path_ok(dir)))
335 return daemon_error(dir, "no such repository");
336
337 /*
338 * Security on the cheap.
339 *
340 * We want a readable HEAD, usable "objects" directory, and
341 * a "git-daemon-export-ok" flag that says that the other side
342 * is ok with us doing this.
343 *
344 * path_ok() uses enter_repo() and does whitelist checking.
345 * We only need to make sure the repository is exported.
346 */
347
348 if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
349 logerror("'%s': repository not exported.", path);
350 errno = EACCES;
351 return daemon_error(dir, "repository not exported");
352 }
353
354 if (service->overridable) {
355 service_looking_at = service;
356 service_enabled = -1;
357 git_config(git_daemon_config, NULL);
358 if (0 <= service_enabled)
359 enabled = service_enabled;
360 }
361 if (!enabled) {
362 logerror("'%s': service not enabled for '%s'",
363 service->name, path);
364 errno = EACCES;
365 return daemon_error(dir, "service not enabled");
366 }
367
368 /*
369 * Optionally, a hook can choose to deny access to the
370 * repository depending on the phase of the moon.
371 */
372 if (access_hook && run_access_hook(service, dir, path))
373 return -1;
374
375 /*
376 * We'll ignore SIGTERM from now on, we have a
377 * good client.
378 */
379 signal(SIGTERM, SIG_IGN);
380
381 return service->fn();
382 }
383
384 static void copy_to_log(int fd)
385 {
386 struct strbuf line = STRBUF_INIT;
387 FILE *fp;
388
389 fp = fdopen(fd, "r");
390 if (fp == NULL) {
391 logerror("fdopen of error channel failed");
392 close(fd);
393 return;
394 }
395
396 while (strbuf_getline(&line, fp, '\n') != EOF) {
397 logerror("%s", line.buf);
398 strbuf_setlen(&line, 0);
399 }
400
401 strbuf_release(&line);
402 fclose(fp);
403 }
404
405 static int run_service_command(const char **argv)
406 {
407 struct child_process cld;
408
409 memset(&cld, 0, sizeof(cld));
410 cld.argv = argv;
411 cld.git_cmd = 1;
412 cld.err = -1;
413 if (start_command(&cld))
414 return -1;
415
416 close(0);
417 close(1);
418
419 copy_to_log(cld.err);
420
421 return finish_command(&cld);
422 }
423
424 static int upload_pack(void)
425 {
426 /* Timeout as string */
427 char timeout_buf[64];
428 const char *argv[] = { "upload-pack", "--strict", NULL, ".", NULL };
429
430 argv[2] = timeout_buf;
431
432 snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
433 return run_service_command(argv);
434 }
435
436 static int upload_archive(void)
437 {
438 static const char *argv[] = { "upload-archive", ".", NULL };
439 return run_service_command(argv);
440 }
441
442 static int receive_pack(void)
443 {
444 static const char *argv[] = { "receive-pack", ".", NULL };
445 return run_service_command(argv);
446 }
447
448 static struct daemon_service daemon_service[] = {
449 { "upload-archive", "uploadarch", upload_archive, 0, 1 },
450 { "upload-pack", "uploadpack", upload_pack, 1, 1 },
451 { "receive-pack", "receivepack", receive_pack, 0, 1 },
452 };
453
454 static void enable_service(const char *name, int ena)
455 {
456 int i;
457 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
458 if (!strcmp(daemon_service[i].name, name)) {
459 daemon_service[i].enabled = ena;
460 return;
461 }
462 }
463 die("No such service %s", name);
464 }
465
466 static void make_service_overridable(const char *name, int ena)
467 {
468 int i;
469 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
470 if (!strcmp(daemon_service[i].name, name)) {
471 daemon_service[i].overridable = ena;
472 return;
473 }
474 }
475 die("No such service %s", name);
476 }
477
478 static char *xstrdup_tolower(const char *str)
479 {
480 char *p, *dup = xstrdup(str);
481 for (p = dup; *p; p++)
482 *p = tolower(*p);
483 return dup;
484 }
485
486 static void parse_host_and_port(char *hostport, char **host,
487 char **port)
488 {
489 if (*hostport == '[') {
490 char *end;
491
492 end = strchr(hostport, ']');
493 if (!end)
494 die("Invalid request ('[' without ']')");
495 *end = '\0';
496 *host = hostport + 1;
497 if (!end[1])
498 *port = NULL;
499 else if (end[1] == ':')
500 *port = end + 2;
501 else
502 die("Garbage after end of host part");
503 } else {
504 *host = hostport;
505 *port = strrchr(hostport, ':');
506 if (*port) {
507 **port = '\0';
508 ++*port;
509 }
510 }
511 }
512
513 /*
514 * Read the host as supplied by the client connection.
515 */
516 static void parse_host_arg(char *extra_args, int buflen)
517 {
518 char *val;
519 int vallen;
520 char *end = extra_args + buflen;
521
522 if (extra_args < end && *extra_args) {
523 saw_extended_args = 1;
524 if (strncasecmp("host=", extra_args, 5) == 0) {
525 val = extra_args + 5;
526 vallen = strlen(val) + 1;
527 if (*val) {
528 /* Split <host>:<port> at colon. */
529 char *host;
530 char *port;
531 parse_host_and_port(val, &host, &port);
532 if (port) {
533 free(tcp_port);
534 tcp_port = xstrdup(port);
535 }
536 free(hostname);
537 hostname = xstrdup_tolower(host);
538 }
539
540 /* On to the next one */
541 extra_args = val + vallen;
542 }
543 if (extra_args < end && *extra_args)
544 die("Invalid request");
545 }
546
547 /*
548 * Locate canonical hostname and its IP address.
549 */
550 if (hostname) {
551 #ifndef NO_IPV6
552 struct addrinfo hints;
553 struct addrinfo *ai;
554 int gai;
555 static char addrbuf[HOST_NAME_MAX + 1];
556
557 memset(&hints, 0, sizeof(hints));
558 hints.ai_flags = AI_CANONNAME;
559
560 gai = getaddrinfo(hostname, NULL, &hints, &ai);
561 if (!gai) {
562 struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
563
564 inet_ntop(AF_INET, &sin_addr->sin_addr,
565 addrbuf, sizeof(addrbuf));
566 free(ip_address);
567 ip_address = xstrdup(addrbuf);
568
569 free(canon_hostname);
570 canon_hostname = xstrdup(ai->ai_canonname ?
571 ai->ai_canonname : ip_address);
572
573 freeaddrinfo(ai);
574 }
575 #else
576 struct hostent *hent;
577 struct sockaddr_in sa;
578 char **ap;
579 static char addrbuf[HOST_NAME_MAX + 1];
580
581 hent = gethostbyname(hostname);
582 if (hent) {
583 ap = hent->h_addr_list;
584 memset(&sa, 0, sizeof sa);
585 sa.sin_family = hent->h_addrtype;
586 sa.sin_port = htons(0);
587 memcpy(&sa.sin_addr, *ap, hent->h_length);
588
589 inet_ntop(hent->h_addrtype, &sa.sin_addr,
590 addrbuf, sizeof(addrbuf));
591
592 free(canon_hostname);
593 canon_hostname = xstrdup(hent->h_name);
594 free(ip_address);
595 ip_address = xstrdup(addrbuf);
596 }
597 #endif
598 }
599 }
600
601
602 static int execute(void)
603 {
604 char *line = packet_buffer;
605 int pktlen, len, i;
606 char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
607
608 if (addr)
609 loginfo("Connection from %s:%s", addr, port);
610
611 alarm(init_timeout ? init_timeout : timeout);
612 pktlen = packet_read(0, NULL, NULL, packet_buffer, sizeof(packet_buffer), 0);
613 alarm(0);
614
615 len = strlen(line);
616 if (pktlen != len)
617 loginfo("Extended attributes (%d bytes) exist <%.*s>",
618 (int) pktlen - len,
619 (int) pktlen - len, line + len + 1);
620 if (len && line[len-1] == '\n') {
621 line[--len] = 0;
622 pktlen--;
623 }
624
625 free(hostname);
626 free(canon_hostname);
627 free(ip_address);
628 free(tcp_port);
629 hostname = canon_hostname = ip_address = tcp_port = NULL;
630
631 if (len != pktlen)
632 parse_host_arg(line + len + 1, pktlen - len - 1);
633
634 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
635 struct daemon_service *s = &(daemon_service[i]);
636 int namelen = strlen(s->name);
637 if (!prefixcmp(line, "git-") &&
638 !strncmp(s->name, line + 4, namelen) &&
639 line[namelen + 4] == ' ') {
640 /*
641 * Note: The directory here is probably context sensitive,
642 * and might depend on the actual service being performed.
643 */
644 return run_service(line + namelen + 5, s);
645 }
646 }
647
648 logerror("Protocol error: '%s'", line);
649 return -1;
650 }
651
652 static int addrcmp(const struct sockaddr_storage *s1,
653 const struct sockaddr_storage *s2)
654 {
655 const struct sockaddr *sa1 = (const struct sockaddr*) s1;
656 const struct sockaddr *sa2 = (const struct sockaddr*) s2;
657
658 if (sa1->sa_family != sa2->sa_family)
659 return sa1->sa_family - sa2->sa_family;
660 if (sa1->sa_family == AF_INET)
661 return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
662 &((struct sockaddr_in *)s2)->sin_addr,
663 sizeof(struct in_addr));
664 #ifndef NO_IPV6
665 if (sa1->sa_family == AF_INET6)
666 return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
667 &((struct sockaddr_in6 *)s2)->sin6_addr,
668 sizeof(struct in6_addr));
669 #endif
670 return 0;
671 }
672
673 static int max_connections = 32;
674
675 static unsigned int live_children;
676
677 static struct child {
678 struct child *next;
679 struct child_process cld;
680 struct sockaddr_storage address;
681 } *firstborn;
682
683 static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
684 {
685 struct child *newborn, **cradle;
686
687 newborn = xcalloc(1, sizeof(*newborn));
688 live_children++;
689 memcpy(&newborn->cld, cld, sizeof(*cld));
690 memcpy(&newborn->address, addr, addrlen);
691 for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
692 if (!addrcmp(&(*cradle)->address, &newborn->address))
693 break;
694 newborn->next = *cradle;
695 *cradle = newborn;
696 }
697
698 /*
699 * This gets called if the number of connections grows
700 * past "max_connections".
701 *
702 * We kill the newest connection from a duplicate IP.
703 */
704 static void kill_some_child(void)
705 {
706 const struct child *blanket, *next;
707
708 if (!(blanket = firstborn))
709 return;
710
711 for (; (next = blanket->next); blanket = next)
712 if (!addrcmp(&blanket->address, &next->address)) {
713 kill(blanket->cld.pid, SIGTERM);
714 break;
715 }
716 }
717
718 static void check_dead_children(void)
719 {
720 int status;
721 pid_t pid;
722
723 struct child **cradle, *blanket;
724 for (cradle = &firstborn; (blanket = *cradle);)
725 if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
726 const char *dead = "";
727 if (status)
728 dead = " (with error)";
729 loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
730
731 /* remove the child */
732 *cradle = blanket->next;
733 live_children--;
734 free(blanket);
735 } else
736 cradle = &blanket->next;
737 }
738
739 static char **cld_argv;
740 static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
741 {
742 struct child_process cld = { NULL };
743 char addrbuf[300] = "REMOTE_ADDR=", portbuf[300];
744 char *env[] = { addrbuf, portbuf, NULL };
745
746 if (max_connections && live_children >= max_connections) {
747 kill_some_child();
748 sleep(1); /* give it some time to die */
749 check_dead_children();
750 if (live_children >= max_connections) {
751 close(incoming);
752 logerror("Too many children, dropping connection");
753 return;
754 }
755 }
756
757 if (addr->sa_family == AF_INET) {
758 struct sockaddr_in *sin_addr = (void *) addr;
759 inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf + 12,
760 sizeof(addrbuf) - 12);
761 snprintf(portbuf, sizeof(portbuf), "REMOTE_PORT=%d",
762 ntohs(sin_addr->sin_port));
763 #ifndef NO_IPV6
764 } else if (addr->sa_family == AF_INET6) {
765 struct sockaddr_in6 *sin6_addr = (void *) addr;
766
767 char *buf = addrbuf + 12;
768 *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
769 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf,
770 sizeof(addrbuf) - 13);
771 strcat(buf, "]");
772
773 snprintf(portbuf, sizeof(portbuf), "REMOTE_PORT=%d",
774 ntohs(sin6_addr->sin6_port));
775 #endif
776 }
777
778 cld.env = (const char **)env;
779 cld.argv = (const char **)cld_argv;
780 cld.in = incoming;
781 cld.out = dup(incoming);
782
783 if (start_command(&cld))
784 logerror("unable to fork");
785 else
786 add_child(&cld, addr, addrlen);
787 close(incoming);
788 }
789
790 static void child_handler(int signo)
791 {
792 /*
793 * Otherwise empty handler because systemcalls will get interrupted
794 * upon signal receipt
795 * SysV needs the handler to be rearmed
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 struct socketlist {
811 int *list;
812 size_t nr;
813 size_t alloc;
814 };
815
816 static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
817 {
818 #ifdef NO_IPV6
819 static char ip[INET_ADDRSTRLEN];
820 #else
821 static char ip[INET6_ADDRSTRLEN];
822 #endif
823
824 switch (family) {
825 #ifndef NO_IPV6
826 case AF_INET6:
827 inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
828 break;
829 #endif
830 case AF_INET:
831 inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
832 break;
833 default:
834 strcpy(ip, "<unknown>");
835 }
836 return ip;
837 }
838
839 #ifndef NO_IPV6
840
841 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
842 {
843 int socknum = 0;
844 int maxfd = -1;
845 char pbuf[NI_MAXSERV];
846 struct addrinfo hints, *ai0, *ai;
847 int gai;
848 long flags;
849
850 sprintf(pbuf, "%d", listen_port);
851 memset(&hints, 0, sizeof(hints));
852 hints.ai_family = AF_UNSPEC;
853 hints.ai_socktype = SOCK_STREAM;
854 hints.ai_protocol = IPPROTO_TCP;
855 hints.ai_flags = AI_PASSIVE;
856
857 gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
858 if (gai) {
859 logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
860 return 0;
861 }
862
863 for (ai = ai0; ai; ai = ai->ai_next) {
864 int sockfd;
865
866 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
867 if (sockfd < 0)
868 continue;
869 if (sockfd >= FD_SETSIZE) {
870 logerror("Socket descriptor too large");
871 close(sockfd);
872 continue;
873 }
874
875 #ifdef IPV6_V6ONLY
876 if (ai->ai_family == AF_INET6) {
877 int on = 1;
878 setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
879 &on, sizeof(on));
880 /* Note: error is not fatal */
881 }
882 #endif
883
884 if (set_reuse_addr(sockfd)) {
885 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
886 close(sockfd);
887 continue;
888 }
889
890 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
891 logerror("Could not bind to %s: %s",
892 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
893 strerror(errno));
894 close(sockfd);
895 continue; /* not fatal */
896 }
897 if (listen(sockfd, 5) < 0) {
898 logerror("Could not listen to %s: %s",
899 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
900 strerror(errno));
901 close(sockfd);
902 continue; /* not fatal */
903 }
904
905 flags = fcntl(sockfd, F_GETFD, 0);
906 if (flags >= 0)
907 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
908
909 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
910 socklist->list[socklist->nr++] = sockfd;
911 socknum++;
912
913 if (maxfd < sockfd)
914 maxfd = sockfd;
915 }
916
917 freeaddrinfo(ai0);
918
919 return socknum;
920 }
921
922 #else /* NO_IPV6 */
923
924 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
925 {
926 struct sockaddr_in sin;
927 int sockfd;
928 long flags;
929
930 memset(&sin, 0, sizeof sin);
931 sin.sin_family = AF_INET;
932 sin.sin_port = htons(listen_port);
933
934 if (listen_addr) {
935 /* Well, host better be an IP address here. */
936 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
937 return 0;
938 } else {
939 sin.sin_addr.s_addr = htonl(INADDR_ANY);
940 }
941
942 sockfd = socket(AF_INET, SOCK_STREAM, 0);
943 if (sockfd < 0)
944 return 0;
945
946 if (set_reuse_addr(sockfd)) {
947 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
948 close(sockfd);
949 return 0;
950 }
951
952 if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
953 logerror("Could not bind to %s: %s",
954 ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
955 strerror(errno));
956 close(sockfd);
957 return 0;
958 }
959
960 if (listen(sockfd, 5) < 0) {
961 logerror("Could not listen to %s: %s",
962 ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
963 strerror(errno));
964 close(sockfd);
965 return 0;
966 }
967
968 flags = fcntl(sockfd, F_GETFD, 0);
969 if (flags >= 0)
970 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
971
972 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
973 socklist->list[socklist->nr++] = sockfd;
974 return 1;
975 }
976
977 #endif
978
979 static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
980 {
981 if (!listen_addr->nr)
982 setup_named_sock(NULL, listen_port, socklist);
983 else {
984 int i, socknum;
985 for (i = 0; i < listen_addr->nr; i++) {
986 socknum = setup_named_sock(listen_addr->items[i].string,
987 listen_port, socklist);
988
989 if (socknum == 0)
990 logerror("unable to allocate any listen sockets for host %s on port %u",
991 listen_addr->items[i].string, listen_port);
992 }
993 }
994 }
995
996 static int service_loop(struct socketlist *socklist)
997 {
998 struct pollfd *pfd;
999 int i;
1000
1001 pfd = xcalloc(socklist->nr, sizeof(struct pollfd));
1002
1003 for (i = 0; i < socklist->nr; i++) {
1004 pfd[i].fd = socklist->list[i];
1005 pfd[i].events = POLLIN;
1006 }
1007
1008 signal(SIGCHLD, child_handler);
1009
1010 for (;;) {
1011 int i;
1012
1013 check_dead_children();
1014
1015 if (poll(pfd, socklist->nr, -1) < 0) {
1016 if (errno != EINTR) {
1017 logerror("Poll failed, resuming: %s",
1018 strerror(errno));
1019 sleep(1);
1020 }
1021 continue;
1022 }
1023
1024 for (i = 0; i < socklist->nr; i++) {
1025 if (pfd[i].revents & POLLIN) {
1026 union {
1027 struct sockaddr sa;
1028 struct sockaddr_in sai;
1029 #ifndef NO_IPV6
1030 struct sockaddr_in6 sai6;
1031 #endif
1032 } ss;
1033 socklen_t sslen = sizeof(ss);
1034 int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1035 if (incoming < 0) {
1036 switch (errno) {
1037 case EAGAIN:
1038 case EINTR:
1039 case ECONNABORTED:
1040 continue;
1041 default:
1042 die_errno("accept returned");
1043 }
1044 }
1045 handle(incoming, &ss.sa, sslen);
1046 }
1047 }
1048 }
1049 }
1050
1051 #ifdef NO_POSIX_GOODIES
1052
1053 struct credentials;
1054
1055 static void drop_privileges(struct credentials *cred)
1056 {
1057 /* nothing */
1058 }
1059
1060 static void daemonize(void)
1061 {
1062 die("--detach not supported on this platform");
1063 }
1064
1065 static struct credentials *prepare_credentials(const char *user_name,
1066 const char *group_name)
1067 {
1068 die("--user not supported on this platform");
1069 }
1070
1071 #else
1072
1073 struct credentials {
1074 struct passwd *pass;
1075 gid_t gid;
1076 };
1077
1078 static void drop_privileges(struct credentials *cred)
1079 {
1080 if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1081 setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1082 die("cannot drop privileges");
1083 }
1084
1085 static struct credentials *prepare_credentials(const char *user_name,
1086 const char *group_name)
1087 {
1088 static struct credentials c;
1089
1090 c.pass = getpwnam(user_name);
1091 if (!c.pass)
1092 die("user not found - %s", user_name);
1093
1094 if (!group_name)
1095 c.gid = c.pass->pw_gid;
1096 else {
1097 struct group *group = getgrnam(group_name);
1098 if (!group)
1099 die("group not found - %s", group_name);
1100
1101 c.gid = group->gr_gid;
1102 }
1103
1104 return &c;
1105 }
1106
1107 static void daemonize(void)
1108 {
1109 switch (fork()) {
1110 case 0:
1111 break;
1112 case -1:
1113 die_errno("fork failed");
1114 default:
1115 exit(0);
1116 }
1117 if (setsid() == -1)
1118 die_errno("setsid failed");
1119 close(0);
1120 close(1);
1121 close(2);
1122 sanitize_stdfds();
1123 }
1124 #endif
1125
1126 static void store_pid(const char *path)
1127 {
1128 FILE *f = fopen(path, "w");
1129 if (!f)
1130 die_errno("cannot open pid file '%s'", path);
1131 if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0)
1132 die_errno("failed to write pid file '%s'", path);
1133 }
1134
1135 static int serve(struct string_list *listen_addr, int listen_port,
1136 struct credentials *cred)
1137 {
1138 struct socketlist socklist = { NULL, 0, 0 };
1139
1140 socksetup(listen_addr, listen_port, &socklist);
1141 if (socklist.nr == 0)
1142 die("unable to allocate any listen sockets on port %u",
1143 listen_port);
1144
1145 drop_privileges(cred);
1146
1147 loginfo("Ready to rumble");
1148
1149 return service_loop(&socklist);
1150 }
1151
1152 int main(int argc, char **argv)
1153 {
1154 int listen_port = 0;
1155 struct string_list listen_addr = STRING_LIST_INIT_NODUP;
1156 int serve_mode = 0, inetd_mode = 0;
1157 const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1158 int detach = 0;
1159 struct credentials *cred = NULL;
1160 int i;
1161
1162 git_setup_gettext();
1163
1164 git_extract_argv0_path(argv[0]);
1165
1166 for (i = 1; i < argc; i++) {
1167 char *arg = argv[i];
1168
1169 if (!prefixcmp(arg, "--listen=")) {
1170 string_list_append(&listen_addr, xstrdup_tolower(arg + 9));
1171 continue;
1172 }
1173 if (!prefixcmp(arg, "--port=")) {
1174 char *end;
1175 unsigned long n;
1176 n = strtoul(arg+7, &end, 0);
1177 if (arg[7] && !*end) {
1178 listen_port = n;
1179 continue;
1180 }
1181 }
1182 if (!strcmp(arg, "--serve")) {
1183 serve_mode = 1;
1184 continue;
1185 }
1186 if (!strcmp(arg, "--inetd")) {
1187 inetd_mode = 1;
1188 log_syslog = 1;
1189 continue;
1190 }
1191 if (!strcmp(arg, "--verbose")) {
1192 verbose = 1;
1193 continue;
1194 }
1195 if (!strcmp(arg, "--syslog")) {
1196 log_syslog = 1;
1197 continue;
1198 }
1199 if (!strcmp(arg, "--export-all")) {
1200 export_all_trees = 1;
1201 continue;
1202 }
1203 if (!prefixcmp(arg, "--access-hook=")) {
1204 access_hook = arg + 14;
1205 continue;
1206 }
1207 if (!prefixcmp(arg, "--timeout=")) {
1208 timeout = atoi(arg+10);
1209 continue;
1210 }
1211 if (!prefixcmp(arg, "--init-timeout=")) {
1212 init_timeout = atoi(arg+15);
1213 continue;
1214 }
1215 if (!prefixcmp(arg, "--max-connections=")) {
1216 max_connections = atoi(arg+18);
1217 if (max_connections < 0)
1218 max_connections = 0; /* unlimited */
1219 continue;
1220 }
1221 if (!strcmp(arg, "--strict-paths")) {
1222 strict_paths = 1;
1223 continue;
1224 }
1225 if (!prefixcmp(arg, "--base-path=")) {
1226 base_path = arg+12;
1227 continue;
1228 }
1229 if (!strcmp(arg, "--base-path-relaxed")) {
1230 base_path_relaxed = 1;
1231 continue;
1232 }
1233 if (!prefixcmp(arg, "--interpolated-path=")) {
1234 interpolated_path = arg+20;
1235 continue;
1236 }
1237 if (!strcmp(arg, "--reuseaddr")) {
1238 reuseaddr = 1;
1239 continue;
1240 }
1241 if (!strcmp(arg, "--user-path")) {
1242 user_path = "";
1243 continue;
1244 }
1245 if (!prefixcmp(arg, "--user-path=")) {
1246 user_path = arg + 12;
1247 continue;
1248 }
1249 if (!prefixcmp(arg, "--pid-file=")) {
1250 pid_file = arg + 11;
1251 continue;
1252 }
1253 if (!strcmp(arg, "--detach")) {
1254 detach = 1;
1255 log_syslog = 1;
1256 continue;
1257 }
1258 if (!prefixcmp(arg, "--user=")) {
1259 user_name = arg + 7;
1260 continue;
1261 }
1262 if (!prefixcmp(arg, "--group=")) {
1263 group_name = arg + 8;
1264 continue;
1265 }
1266 if (!prefixcmp(arg, "--enable=")) {
1267 enable_service(arg + 9, 1);
1268 continue;
1269 }
1270 if (!prefixcmp(arg, "--disable=")) {
1271 enable_service(arg + 10, 0);
1272 continue;
1273 }
1274 if (!prefixcmp(arg, "--allow-override=")) {
1275 make_service_overridable(arg + 17, 1);
1276 continue;
1277 }
1278 if (!prefixcmp(arg, "--forbid-override=")) {
1279 make_service_overridable(arg + 18, 0);
1280 continue;
1281 }
1282 if (!strcmp(arg, "--informative-errors")) {
1283 informative_errors = 1;
1284 continue;
1285 }
1286 if (!strcmp(arg, "--no-informative-errors")) {
1287 informative_errors = 0;
1288 continue;
1289 }
1290 if (!strcmp(arg, "--")) {
1291 ok_paths = &argv[i+1];
1292 break;
1293 } else if (arg[0] != '-') {
1294 ok_paths = &argv[i];
1295 break;
1296 }
1297
1298 usage(daemon_usage);
1299 }
1300
1301 if (log_syslog) {
1302 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1303 set_die_routine(daemon_die);
1304 } else
1305 /* avoid splitting a message in the middle */
1306 setvbuf(stderr, NULL, _IOFBF, 4096);
1307
1308 if (inetd_mode && (detach || group_name || user_name))
1309 die("--detach, --user and --group are incompatible with --inetd");
1310
1311 if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1312 die("--listen= and --port= are incompatible with --inetd");
1313 else if (listen_port == 0)
1314 listen_port = DEFAULT_GIT_PORT;
1315
1316 if (group_name && !user_name)
1317 die("--group supplied without --user");
1318
1319 if (user_name)
1320 cred = prepare_credentials(user_name, group_name);
1321
1322 if (strict_paths && (!ok_paths || !*ok_paths))
1323 die("option --strict-paths requires a whitelist");
1324
1325 if (base_path && !is_directory(base_path))
1326 die("base-path '%s' does not exist or is not a directory",
1327 base_path);
1328
1329 if (inetd_mode) {
1330 if (!freopen("/dev/null", "w", stderr))
1331 die_errno("failed to redirect stderr to /dev/null");
1332 }
1333
1334 if (inetd_mode || serve_mode)
1335 return execute();
1336
1337 if (detach)
1338 daemonize();
1339 else
1340 sanitize_stdfds();
1341
1342 if (pid_file)
1343 store_pid(pid_file);
1344
1345 /* prepare argv for serving-processes */
1346 cld_argv = xmalloc(sizeof (char *) * (argc + 2));
1347 cld_argv[0] = argv[0]; /* git-daemon */
1348 cld_argv[1] = "--serve";
1349 for (i = 1; i < argc; ++i)
1350 cld_argv[i+1] = argv[i];
1351 cld_argv[argc+1] = NULL;
1352
1353 return serve(&listen_addr, listen_port, cred);
1354 }