daemon: support <directory> arguments again
[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 #ifndef NI_MAXSERV
13 #define NI_MAXSERV 32
14 #endif
15
16 #ifdef NO_INITGROUPS
17 #define initgroups(x, y) (0) /* nothing */
18 #endif
19
20 static int log_syslog;
21 static int verbose;
22 static int reuseaddr;
23
24 static const char daemon_usage[] =
25 "git daemon [--verbose] [--syslog] [--export-all]\n"
26 " [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n"
27 " [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
28 " [--user-path | --user-path=<path>]\n"
29 " [--interpolated-path=<path>]\n"
30 " [--reuseaddr] [--pid-file=<file>]\n"
31 " [--(enable|disable|allow-override|forbid-override)=<service>]\n"
32 " [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
33 " [--detach] [--user=<user> [--group=<group>]]\n"
34 " [<directory>...]";
35
36 /* List of acceptable pathname prefixes */
37 static char **ok_paths;
38 static int strict_paths;
39
40 /* If this is set, git-daemon-export-ok is not required */
41 static int export_all_trees;
42
43 /* Take all paths relative to this one if non-NULL */
44 static char *base_path;
45 static char *interpolated_path;
46 static int base_path_relaxed;
47
48 /* Flag indicating client sent extra args. */
49 static int saw_extended_args;
50
51 /* If defined, ~user notation is allowed and the string is inserted
52 * after ~user/. E.g. a request to git://host/~alice/frotz would
53 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
54 */
55 static const char *user_path;
56
57 /* Timeout, and initial timeout */
58 static unsigned int timeout;
59 static unsigned int init_timeout;
60
61 static char *hostname;
62 static char *canon_hostname;
63 static char *ip_address;
64 static char *tcp_port;
65
66 static void logreport(int priority, const char *err, va_list params)
67 {
68 if (log_syslog) {
69 char buf[1024];
70 vsnprintf(buf, sizeof(buf), err, params);
71 syslog(priority, "%s", buf);
72 } else {
73 /*
74 * Since stderr is set to buffered mode, the
75 * logging of different processes will not overlap
76 * unless they overflow the (rather big) buffers.
77 */
78 fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
79 vfprintf(stderr, err, params);
80 fputc('\n', stderr);
81 fflush(stderr);
82 }
83 }
84
85 __attribute__((format (printf, 1, 2)))
86 static void logerror(const char *err, ...)
87 {
88 va_list params;
89 va_start(params, err);
90 logreport(LOG_ERR, err, params);
91 va_end(params);
92 }
93
94 __attribute__((format (printf, 1, 2)))
95 static void loginfo(const char *err, ...)
96 {
97 va_list params;
98 if (!verbose)
99 return;
100 va_start(params, err);
101 logreport(LOG_INFO, err, params);
102 va_end(params);
103 }
104
105 static void NORETURN daemon_die(const char *err, va_list params)
106 {
107 logreport(LOG_ERR, err, params);
108 exit(1);
109 }
110
111 static char *path_ok(char *directory)
112 {
113 static char rpath[PATH_MAX];
114 static char interp_path[PATH_MAX];
115 char *path;
116 char *dir;
117
118 dir = directory;
119
120 if (daemon_avoid_alias(dir)) {
121 logerror("'%s': aliased", dir);
122 return NULL;
123 }
124
125 if (*dir == '~') {
126 if (!user_path) {
127 logerror("'%s': User-path not allowed", dir);
128 return NULL;
129 }
130 if (*user_path) {
131 /* Got either "~alice" or "~alice/foo";
132 * rewrite them to "~alice/%s" or
133 * "~alice/%s/foo".
134 */
135 int namlen, restlen = strlen(dir);
136 char *slash = strchr(dir, '/');
137 if (!slash)
138 slash = dir + restlen;
139 namlen = slash - dir;
140 restlen -= namlen;
141 loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
142 snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
143 namlen, dir, user_path, restlen, slash);
144 dir = rpath;
145 }
146 }
147 else if (interpolated_path && saw_extended_args) {
148 struct strbuf expanded_path = STRBUF_INIT;
149 struct strbuf_expand_dict_entry dict[6];
150
151 dict[0].placeholder = "H"; dict[0].value = hostname;
152 dict[1].placeholder = "CH"; dict[1].value = canon_hostname;
153 dict[2].placeholder = "IP"; dict[2].value = ip_address;
154 dict[3].placeholder = "P"; dict[3].value = tcp_port;
155 dict[4].placeholder = "D"; dict[4].value = directory;
156 dict[5].placeholder = NULL; dict[5].value = NULL;
157 if (*dir != '/') {
158 /* Allow only absolute */
159 logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
160 return NULL;
161 }
162
163 strbuf_expand(&expanded_path, interpolated_path,
164 strbuf_expand_dict_cb, &dict);
165 strlcpy(interp_path, expanded_path.buf, PATH_MAX);
166 strbuf_release(&expanded_path);
167 loginfo("Interpolated dir '%s'", interp_path);
168
169 dir = interp_path;
170 }
171 else if (base_path) {
172 if (*dir != '/') {
173 /* Allow only absolute */
174 logerror("'%s': Non-absolute path denied (base-path active)", dir);
175 return NULL;
176 }
177 snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
178 dir = rpath;
179 }
180
181 path = enter_repo(dir, strict_paths);
182 if (!path && base_path && base_path_relaxed) {
183 /*
184 * if we fail and base_path_relaxed is enabled, try without
185 * prefixing the base path
186 */
187 dir = directory;
188 path = enter_repo(dir, strict_paths);
189 }
190
191 if (!path) {
192 logerror("'%s' does not appear to be a git repository", dir);
193 return NULL;
194 }
195
196 if ( ok_paths && *ok_paths ) {
197 char **pp;
198 int pathlen = strlen(path);
199
200 /* The validation is done on the paths after enter_repo
201 * appends optional {.git,.git/.git} and friends, but
202 * it does not use getcwd(). So if your /pub is
203 * a symlink to /mnt/pub, you can whitelist /pub and
204 * do not have to say /mnt/pub.
205 * Do not say /pub/.
206 */
207 for ( pp = ok_paths ; *pp ; pp++ ) {
208 int len = strlen(*pp);
209 if (len <= pathlen &&
210 !memcmp(*pp, path, len) &&
211 (path[len] == '\0' ||
212 (!strict_paths && path[len] == '/')))
213 return path;
214 }
215 }
216 else {
217 /* be backwards compatible */
218 if (!strict_paths)
219 return path;
220 }
221
222 logerror("'%s': not in whitelist", path);
223 return NULL; /* Fallthrough. Deny by default */
224 }
225
226 typedef int (*daemon_service_fn)(void);
227 struct daemon_service {
228 const char *name;
229 const char *config_name;
230 daemon_service_fn fn;
231 int enabled;
232 int overridable;
233 };
234
235 static struct daemon_service *service_looking_at;
236 static int service_enabled;
237
238 static int git_daemon_config(const char *var, const char *value, void *cb)
239 {
240 if (!prefixcmp(var, "daemon.") &&
241 !strcmp(var + 7, service_looking_at->config_name)) {
242 service_enabled = git_config_bool(var, value);
243 return 0;
244 }
245
246 /* we are not interested in parsing any other configuration here */
247 return 0;
248 }
249
250 static int run_service(char *dir, struct daemon_service *service)
251 {
252 const char *path;
253 int enabled = service->enabled;
254
255 loginfo("Request %s for '%s'", service->name, dir);
256
257 if (!enabled && !service->overridable) {
258 logerror("'%s': service not enabled.", service->name);
259 errno = EACCES;
260 return -1;
261 }
262
263 if (!(path = path_ok(dir)))
264 return -1;
265
266 /*
267 * Security on the cheap.
268 *
269 * We want a readable HEAD, usable "objects" directory, and
270 * a "git-daemon-export-ok" flag that says that the other side
271 * is ok with us doing this.
272 *
273 * path_ok() uses enter_repo() and does whitelist checking.
274 * We only need to make sure the repository is exported.
275 */
276
277 if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
278 logerror("'%s': repository not exported.", path);
279 errno = EACCES;
280 return -1;
281 }
282
283 if (service->overridable) {
284 service_looking_at = service;
285 service_enabled = -1;
286 git_config(git_daemon_config, NULL);
287 if (0 <= service_enabled)
288 enabled = service_enabled;
289 }
290 if (!enabled) {
291 logerror("'%s': service not enabled for '%s'",
292 service->name, path);
293 errno = EACCES;
294 return -1;
295 }
296
297 /*
298 * We'll ignore SIGTERM from now on, we have a
299 * good client.
300 */
301 signal(SIGTERM, SIG_IGN);
302
303 return service->fn();
304 }
305
306 static void copy_to_log(int fd)
307 {
308 struct strbuf line = STRBUF_INIT;
309 FILE *fp;
310
311 fp = fdopen(fd, "r");
312 if (fp == NULL) {
313 logerror("fdopen of error channel failed");
314 close(fd);
315 return;
316 }
317
318 while (strbuf_getline(&line, fp, '\n') != EOF) {
319 logerror("%s", line.buf);
320 strbuf_setlen(&line, 0);
321 }
322
323 strbuf_release(&line);
324 fclose(fp);
325 }
326
327 static int run_service_command(const char **argv)
328 {
329 struct child_process cld;
330
331 memset(&cld, 0, sizeof(cld));
332 cld.argv = argv;
333 cld.git_cmd = 1;
334 cld.err = -1;
335 if (start_command(&cld))
336 return -1;
337
338 close(0);
339 close(1);
340
341 copy_to_log(cld.err);
342
343 return finish_command(&cld);
344 }
345
346 static int upload_pack(void)
347 {
348 /* Timeout as string */
349 char timeout_buf[64];
350 const char *argv[] = { "upload-pack", "--strict", NULL, ".", NULL };
351
352 argv[2] = timeout_buf;
353
354 snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
355 return run_service_command(argv);
356 }
357
358 static int upload_archive(void)
359 {
360 static const char *argv[] = { "upload-archive", ".", NULL };
361 return run_service_command(argv);
362 }
363
364 static int receive_pack(void)
365 {
366 static const char *argv[] = { "receive-pack", ".", NULL };
367 return run_service_command(argv);
368 }
369
370 static struct daemon_service daemon_service[] = {
371 { "upload-archive", "uploadarch", upload_archive, 0, 1 },
372 { "upload-pack", "uploadpack", upload_pack, 1, 1 },
373 { "receive-pack", "receivepack", receive_pack, 0, 1 },
374 };
375
376 static void enable_service(const char *name, int ena)
377 {
378 int i;
379 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
380 if (!strcmp(daemon_service[i].name, name)) {
381 daemon_service[i].enabled = ena;
382 return;
383 }
384 }
385 die("No such service %s", name);
386 }
387
388 static void make_service_overridable(const char *name, int ena)
389 {
390 int i;
391 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
392 if (!strcmp(daemon_service[i].name, name)) {
393 daemon_service[i].overridable = ena;
394 return;
395 }
396 }
397 die("No such service %s", name);
398 }
399
400 static char *xstrdup_tolower(const char *str)
401 {
402 char *p, *dup = xstrdup(str);
403 for (p = dup; *p; p++)
404 *p = tolower(*p);
405 return dup;
406 }
407
408 static void parse_host_and_port(char *hostport, char **host,
409 char **port)
410 {
411 if (*hostport == '[') {
412 char *end;
413
414 end = strchr(hostport, ']');
415 if (!end)
416 die("Invalid request ('[' without ']')");
417 *end = '\0';
418 *host = hostport + 1;
419 if (!end[1])
420 *port = NULL;
421 else if (end[1] == ':')
422 *port = end + 2;
423 else
424 die("Garbage after end of host part");
425 } else {
426 *host = hostport;
427 *port = strrchr(hostport, ':');
428 if (*port) {
429 **port = '\0';
430 ++*port;
431 }
432 }
433 }
434
435 /*
436 * Read the host as supplied by the client connection.
437 */
438 static void parse_host_arg(char *extra_args, int buflen)
439 {
440 char *val;
441 int vallen;
442 char *end = extra_args + buflen;
443
444 if (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;
452 char *port;
453 parse_host_and_port(val, &host, &port);
454 if (port) {
455 free(tcp_port);
456 tcp_port = xstrdup(port);
457 }
458 free(hostname);
459 hostname = xstrdup_tolower(host);
460 }
461
462 /* On to the next one */
463 extra_args = val + vallen;
464 }
465 if (extra_args < end && *extra_args)
466 die("Invalid request");
467 }
468
469 /*
470 * Locate canonical hostname and its IP address.
471 */
472 if (hostname) {
473 #ifndef NO_IPV6
474 struct addrinfo hints;
475 struct addrinfo *ai;
476 int gai;
477 static char addrbuf[HOST_NAME_MAX + 1];
478
479 memset(&hints, 0, sizeof(hints));
480 hints.ai_flags = AI_CANONNAME;
481
482 gai = getaddrinfo(hostname, NULL, &hints, &ai);
483 if (!gai) {
484 struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
485
486 inet_ntop(AF_INET, &sin_addr->sin_addr,
487 addrbuf, sizeof(addrbuf));
488 free(ip_address);
489 ip_address = xstrdup(addrbuf);
490
491 free(canon_hostname);
492 canon_hostname = xstrdup(ai->ai_canonname ?
493 ai->ai_canonname : ip_address);
494
495 freeaddrinfo(ai);
496 }
497 #else
498 struct hostent *hent;
499 struct sockaddr_in sa;
500 char **ap;
501 static char addrbuf[HOST_NAME_MAX + 1];
502
503 hent = gethostbyname(hostname);
504
505 ap = hent->h_addr_list;
506 memset(&sa, 0, sizeof sa);
507 sa.sin_family = hent->h_addrtype;
508 sa.sin_port = htons(0);
509 memcpy(&sa.sin_addr, *ap, hent->h_length);
510
511 inet_ntop(hent->h_addrtype, &sa.sin_addr,
512 addrbuf, sizeof(addrbuf));
513
514 free(canon_hostname);
515 canon_hostname = xstrdup(hent->h_name);
516 free(ip_address);
517 ip_address = xstrdup(addrbuf);
518 #endif
519 }
520 }
521
522
523 static int execute(void)
524 {
525 static char line[1000];
526 int pktlen, len, i;
527 char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
528
529 if (addr)
530 loginfo("Connection from %s:%s", addr, port);
531
532 alarm(init_timeout ? init_timeout : timeout);
533 pktlen = packet_read_line(0, line, sizeof(line));
534 alarm(0);
535
536 len = strlen(line);
537 if (pktlen != len)
538 loginfo("Extended attributes (%d bytes) exist <%.*s>",
539 (int) pktlen - len,
540 (int) pktlen - len, line + len + 1);
541 if (len && line[len-1] == '\n') {
542 line[--len] = 0;
543 pktlen--;
544 }
545
546 free(hostname);
547 free(canon_hostname);
548 free(ip_address);
549 free(tcp_port);
550 hostname = canon_hostname = ip_address = tcp_port = NULL;
551
552 if (len != pktlen)
553 parse_host_arg(line + len + 1, pktlen - len - 1);
554
555 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
556 struct daemon_service *s = &(daemon_service[i]);
557 int namelen = strlen(s->name);
558 if (!prefixcmp(line, "git-") &&
559 !strncmp(s->name, line + 4, namelen) &&
560 line[namelen + 4] == ' ') {
561 /*
562 * Note: The directory here is probably context sensitive,
563 * and might depend on the actual service being performed.
564 */
565 return run_service(line + namelen + 5, s);
566 }
567 }
568
569 logerror("Protocol error: '%s'", line);
570 return -1;
571 }
572
573 static int addrcmp(const struct sockaddr_storage *s1,
574 const struct sockaddr_storage *s2)
575 {
576 const struct sockaddr *sa1 = (const struct sockaddr*) s1;
577 const struct sockaddr *sa2 = (const struct sockaddr*) s2;
578
579 if (sa1->sa_family != sa2->sa_family)
580 return sa1->sa_family - sa2->sa_family;
581 if (sa1->sa_family == AF_INET)
582 return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
583 &((struct sockaddr_in *)s2)->sin_addr,
584 sizeof(struct in_addr));
585 #ifndef NO_IPV6
586 if (sa1->sa_family == AF_INET6)
587 return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
588 &((struct sockaddr_in6 *)s2)->sin6_addr,
589 sizeof(struct in6_addr));
590 #endif
591 return 0;
592 }
593
594 static int max_connections = 32;
595
596 static unsigned int live_children;
597
598 static struct child {
599 struct child *next;
600 struct child_process cld;
601 struct sockaddr_storage address;
602 } *firstborn;
603
604 static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
605 {
606 struct child *newborn, **cradle;
607
608 newborn = xcalloc(1, sizeof(*newborn));
609 live_children++;
610 memcpy(&newborn->cld, cld, sizeof(*cld));
611 memcpy(&newborn->address, addr, addrlen);
612 for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
613 if (!addrcmp(&(*cradle)->address, &newborn->address))
614 break;
615 newborn->next = *cradle;
616 *cradle = newborn;
617 }
618
619 /*
620 * This gets called if the number of connections grows
621 * past "max_connections".
622 *
623 * We kill the newest connection from a duplicate IP.
624 */
625 static void kill_some_child(void)
626 {
627 const struct child *blanket, *next;
628
629 if (!(blanket = firstborn))
630 return;
631
632 for (; (next = blanket->next); blanket = next)
633 if (!addrcmp(&blanket->address, &next->address)) {
634 kill(blanket->cld.pid, SIGTERM);
635 break;
636 }
637 }
638
639 static void check_dead_children(void)
640 {
641 int status;
642 pid_t pid;
643
644 struct child **cradle, *blanket;
645 for (cradle = &firstborn; (blanket = *cradle);)
646 if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
647 const char *dead = "";
648 if (status)
649 dead = " (with error)";
650 loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
651
652 /* remove the child */
653 *cradle = blanket->next;
654 live_children--;
655 free(blanket);
656 } else
657 cradle = &blanket->next;
658 }
659
660 static char **cld_argv;
661 static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
662 {
663 struct child_process cld = { 0 };
664 char addrbuf[300] = "REMOTE_ADDR=", portbuf[300];
665 char *env[] = { addrbuf, portbuf, NULL };
666
667 if (max_connections && live_children >= max_connections) {
668 kill_some_child();
669 sleep(1); /* give it some time to die */
670 check_dead_children();
671 if (live_children >= max_connections) {
672 close(incoming);
673 logerror("Too many children, dropping connection");
674 return;
675 }
676 }
677
678 if (addr->sa_family == AF_INET) {
679 struct sockaddr_in *sin_addr = (void *) addr;
680 inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf + 12,
681 sizeof(addrbuf) - 12);
682 snprintf(portbuf, sizeof(portbuf), "REMOTE_PORT=%d",
683 ntohs(sin_addr->sin_port));
684 #ifndef NO_IPV6
685 } else if (addr && addr->sa_family == AF_INET6) {
686 struct sockaddr_in6 *sin6_addr = (void *) addr;
687
688 char *buf = addrbuf + 12;
689 *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
690 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf,
691 sizeof(addrbuf) - 13);
692 strcat(buf, "]");
693
694 snprintf(portbuf, sizeof(portbuf), "REMOTE_PORT=%d",
695 ntohs(sin6_addr->sin6_port));
696 #endif
697 }
698
699 cld.env = (const char **)env;
700 cld.argv = (const char **)cld_argv;
701 cld.in = incoming;
702 cld.out = dup(incoming);
703
704 if (start_command(&cld))
705 logerror("unable to fork");
706 else
707 add_child(&cld, addr, addrlen);
708 close(incoming);
709 }
710
711 static void child_handler(int signo)
712 {
713 /*
714 * Otherwise empty handler because systemcalls will get interrupted
715 * upon signal receipt
716 * SysV needs the handler to be rearmed
717 */
718 signal(SIGCHLD, child_handler);
719 }
720
721 static int set_reuse_addr(int sockfd)
722 {
723 int on = 1;
724
725 if (!reuseaddr)
726 return 0;
727 return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
728 &on, sizeof(on));
729 }
730
731 struct socketlist {
732 int *list;
733 size_t nr;
734 size_t alloc;
735 };
736
737 #ifndef NO_IPV6
738
739 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
740 {
741 int socknum = 0;
742 int maxfd = -1;
743 char pbuf[NI_MAXSERV];
744 struct addrinfo hints, *ai0, *ai;
745 int gai;
746 long flags;
747
748 sprintf(pbuf, "%d", listen_port);
749 memset(&hints, 0, sizeof(hints));
750 hints.ai_family = AF_UNSPEC;
751 hints.ai_socktype = SOCK_STREAM;
752 hints.ai_protocol = IPPROTO_TCP;
753 hints.ai_flags = AI_PASSIVE;
754
755 gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
756 if (gai) {
757 logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
758 return 0;
759 }
760
761 for (ai = ai0; ai; ai = ai->ai_next) {
762 int sockfd;
763
764 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
765 if (sockfd < 0)
766 continue;
767 if (sockfd >= FD_SETSIZE) {
768 logerror("Socket descriptor too large");
769 close(sockfd);
770 continue;
771 }
772
773 #ifdef IPV6_V6ONLY
774 if (ai->ai_family == AF_INET6) {
775 int on = 1;
776 setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
777 &on, sizeof(on));
778 /* Note: error is not fatal */
779 }
780 #endif
781
782 if (set_reuse_addr(sockfd)) {
783 close(sockfd);
784 continue;
785 }
786
787 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
788 close(sockfd);
789 continue; /* not fatal */
790 }
791 if (listen(sockfd, 5) < 0) {
792 close(sockfd);
793 continue; /* not fatal */
794 }
795
796 flags = fcntl(sockfd, F_GETFD, 0);
797 if (flags >= 0)
798 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
799
800 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
801 socklist->list[socklist->nr++] = sockfd;
802 socknum++;
803
804 if (maxfd < sockfd)
805 maxfd = sockfd;
806 }
807
808 freeaddrinfo(ai0);
809
810 return socknum;
811 }
812
813 #else /* NO_IPV6 */
814
815 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
816 {
817 struct sockaddr_in sin;
818 int sockfd;
819 long flags;
820
821 memset(&sin, 0, sizeof sin);
822 sin.sin_family = AF_INET;
823 sin.sin_port = htons(listen_port);
824
825 if (listen_addr) {
826 /* Well, host better be an IP address here. */
827 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
828 return 0;
829 } else {
830 sin.sin_addr.s_addr = htonl(INADDR_ANY);
831 }
832
833 sockfd = socket(AF_INET, SOCK_STREAM, 0);
834 if (sockfd < 0)
835 return 0;
836
837 if (set_reuse_addr(sockfd)) {
838 close(sockfd);
839 return 0;
840 }
841
842 if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
843 close(sockfd);
844 return 0;
845 }
846
847 if (listen(sockfd, 5) < 0) {
848 close(sockfd);
849 return 0;
850 }
851
852 flags = fcntl(sockfd, F_GETFD, 0);
853 if (flags >= 0)
854 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
855
856 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
857 socklist->list[socklist->nr++] = sockfd;
858 return 1;
859 }
860
861 #endif
862
863 static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
864 {
865 if (!listen_addr->nr)
866 setup_named_sock(NULL, listen_port, socklist);
867 else {
868 int i, socknum;
869 for (i = 0; i < listen_addr->nr; i++) {
870 socknum = setup_named_sock(listen_addr->items[i].string,
871 listen_port, socklist);
872
873 if (socknum == 0)
874 logerror("unable to allocate any listen sockets for host %s on port %u",
875 listen_addr->items[i].string, listen_port);
876 }
877 }
878 }
879
880 static int service_loop(struct socketlist *socklist)
881 {
882 struct pollfd *pfd;
883 int i;
884
885 pfd = xcalloc(socklist->nr, sizeof(struct pollfd));
886
887 for (i = 0; i < socklist->nr; i++) {
888 pfd[i].fd = socklist->list[i];
889 pfd[i].events = POLLIN;
890 }
891
892 signal(SIGCHLD, child_handler);
893
894 for (;;) {
895 int i;
896
897 check_dead_children();
898
899 if (poll(pfd, socklist->nr, -1) < 0) {
900 if (errno != EINTR) {
901 logerror("Poll failed, resuming: %s",
902 strerror(errno));
903 sleep(1);
904 }
905 continue;
906 }
907
908 for (i = 0; i < socklist->nr; i++) {
909 if (pfd[i].revents & POLLIN) {
910 union {
911 struct sockaddr sa;
912 struct sockaddr_in sai;
913 #ifndef NO_IPV6
914 struct sockaddr_in6 sai6;
915 #endif
916 } ss;
917 socklen_t sslen = sizeof(ss);
918 int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
919 if (incoming < 0) {
920 switch (errno) {
921 case EAGAIN:
922 case EINTR:
923 case ECONNABORTED:
924 continue;
925 default:
926 die_errno("accept returned");
927 }
928 }
929 handle(incoming, &ss.sa, sslen);
930 }
931 }
932 }
933 }
934
935 /* if any standard file descriptor is missing open it to /dev/null */
936 static void sanitize_stdfds(void)
937 {
938 int fd = open("/dev/null", O_RDWR, 0);
939 while (fd != -1 && fd < 2)
940 fd = dup(fd);
941 if (fd == -1)
942 die_errno("open /dev/null or dup failed");
943 if (fd > 2)
944 close(fd);
945 }
946
947 #ifdef NO_POSIX_GOODIES
948
949 struct credentials;
950
951 static void drop_privileges(struct credentials *cred)
952 {
953 /* nothing */
954 }
955
956 static void daemonize(void)
957 {
958 die("--detach not supported on this platform");
959 }
960
961 static struct credentials *prepare_credentials(const char *user_name,
962 const char *group_name)
963 {
964 die("--user not supported on this platform");
965 }
966
967 #else
968
969 struct credentials {
970 struct passwd *pass;
971 gid_t gid;
972 };
973
974 static void drop_privileges(struct credentials *cred)
975 {
976 if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
977 setgid (cred->gid) || setuid(cred->pass->pw_uid)))
978 die("cannot drop privileges");
979 }
980
981 static struct credentials *prepare_credentials(const char *user_name,
982 const char *group_name)
983 {
984 static struct credentials c;
985
986 c.pass = getpwnam(user_name);
987 if (!c.pass)
988 die("user not found - %s", user_name);
989
990 if (!group_name)
991 c.gid = c.pass->pw_gid;
992 else {
993 struct group *group = getgrnam(group_name);
994 if (!group)
995 die("group not found - %s", group_name);
996
997 c.gid = group->gr_gid;
998 }
999
1000 return &c;
1001 }
1002
1003 static void daemonize(void)
1004 {
1005 switch (fork()) {
1006 case 0:
1007 break;
1008 case -1:
1009 die_errno("fork failed");
1010 default:
1011 exit(0);
1012 }
1013 if (setsid() == -1)
1014 die_errno("setsid failed");
1015 close(0);
1016 close(1);
1017 close(2);
1018 sanitize_stdfds();
1019 }
1020 #endif
1021
1022 static void store_pid(const char *path)
1023 {
1024 FILE *f = fopen(path, "w");
1025 if (!f)
1026 die_errno("cannot open pid file '%s'", path);
1027 if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0)
1028 die_errno("failed to write pid file '%s'", path);
1029 }
1030
1031 static int serve(struct string_list *listen_addr, int listen_port,
1032 struct credentials *cred)
1033 {
1034 struct socketlist socklist = { NULL, 0, 0 };
1035
1036 socksetup(listen_addr, listen_port, &socklist);
1037 if (socklist.nr == 0)
1038 die("unable to allocate any listen sockets on port %u",
1039 listen_port);
1040
1041 drop_privileges(cred);
1042
1043 return service_loop(&socklist);
1044 }
1045
1046 int main(int argc, char **argv)
1047 {
1048 int listen_port = 0;
1049 struct string_list listen_addr = STRING_LIST_INIT_NODUP;
1050 int serve_mode = 0, inetd_mode = 0;
1051 const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1052 int detach = 0;
1053 struct credentials *cred = NULL;
1054 int i;
1055
1056 git_extract_argv0_path(argv[0]);
1057
1058 for (i = 1; i < argc; i++) {
1059 char *arg = argv[i];
1060
1061 if (!prefixcmp(arg, "--listen=")) {
1062 string_list_append(&listen_addr, xstrdup_tolower(arg + 9));
1063 continue;
1064 }
1065 if (!prefixcmp(arg, "--port=")) {
1066 char *end;
1067 unsigned long n;
1068 n = strtoul(arg+7, &end, 0);
1069 if (arg[7] && !*end) {
1070 listen_port = n;
1071 continue;
1072 }
1073 }
1074 if (!strcmp(arg, "--serve")) {
1075 serve_mode = 1;
1076 continue;
1077 }
1078 if (!strcmp(arg, "--inetd")) {
1079 inetd_mode = 1;
1080 log_syslog = 1;
1081 continue;
1082 }
1083 if (!strcmp(arg, "--verbose")) {
1084 verbose = 1;
1085 continue;
1086 }
1087 if (!strcmp(arg, "--syslog")) {
1088 log_syslog = 1;
1089 continue;
1090 }
1091 if (!strcmp(arg, "--export-all")) {
1092 export_all_trees = 1;
1093 continue;
1094 }
1095 if (!prefixcmp(arg, "--timeout=")) {
1096 timeout = atoi(arg+10);
1097 continue;
1098 }
1099 if (!prefixcmp(arg, "--init-timeout=")) {
1100 init_timeout = atoi(arg+15);
1101 continue;
1102 }
1103 if (!prefixcmp(arg, "--max-connections=")) {
1104 max_connections = atoi(arg+18);
1105 if (max_connections < 0)
1106 max_connections = 0; /* unlimited */
1107 continue;
1108 }
1109 if (!strcmp(arg, "--strict-paths")) {
1110 strict_paths = 1;
1111 continue;
1112 }
1113 if (!prefixcmp(arg, "--base-path=")) {
1114 base_path = arg+12;
1115 continue;
1116 }
1117 if (!strcmp(arg, "--base-path-relaxed")) {
1118 base_path_relaxed = 1;
1119 continue;
1120 }
1121 if (!prefixcmp(arg, "--interpolated-path=")) {
1122 interpolated_path = arg+20;
1123 continue;
1124 }
1125 if (!strcmp(arg, "--reuseaddr")) {
1126 reuseaddr = 1;
1127 continue;
1128 }
1129 if (!strcmp(arg, "--user-path")) {
1130 user_path = "";
1131 continue;
1132 }
1133 if (!prefixcmp(arg, "--user-path=")) {
1134 user_path = arg + 12;
1135 continue;
1136 }
1137 if (!prefixcmp(arg, "--pid-file=")) {
1138 pid_file = arg + 11;
1139 continue;
1140 }
1141 if (!strcmp(arg, "--detach")) {
1142 detach = 1;
1143 log_syslog = 1;
1144 continue;
1145 }
1146 if (!prefixcmp(arg, "--user=")) {
1147 user_name = arg + 7;
1148 continue;
1149 }
1150 if (!prefixcmp(arg, "--group=")) {
1151 group_name = arg + 8;
1152 continue;
1153 }
1154 if (!prefixcmp(arg, "--enable=")) {
1155 enable_service(arg + 9, 1);
1156 continue;
1157 }
1158 if (!prefixcmp(arg, "--disable=")) {
1159 enable_service(arg + 10, 0);
1160 continue;
1161 }
1162 if (!prefixcmp(arg, "--allow-override=")) {
1163 make_service_overridable(arg + 17, 1);
1164 continue;
1165 }
1166 if (!prefixcmp(arg, "--forbid-override=")) {
1167 make_service_overridable(arg + 18, 0);
1168 continue;
1169 }
1170 if (!strcmp(arg, "--")) {
1171 ok_paths = &argv[i+1];
1172 break;
1173 } else if (arg[0] != '-') {
1174 ok_paths = &argv[i];
1175 break;
1176 }
1177
1178 usage(daemon_usage);
1179 }
1180
1181 if (log_syslog) {
1182 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1183 set_die_routine(daemon_die);
1184 } else
1185 /* avoid splitting a message in the middle */
1186 setvbuf(stderr, NULL, _IOFBF, 4096);
1187
1188 if (inetd_mode && (detach || group_name || user_name))
1189 die("--detach, --user and --group are incompatible with --inetd");
1190
1191 if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1192 die("--listen= and --port= are incompatible with --inetd");
1193 else if (listen_port == 0)
1194 listen_port = DEFAULT_GIT_PORT;
1195
1196 if (group_name && !user_name)
1197 die("--group supplied without --user");
1198
1199 if (user_name)
1200 cred = prepare_credentials(user_name, group_name);
1201
1202 if (strict_paths && (!ok_paths || !*ok_paths))
1203 die("option --strict-paths requires a whitelist");
1204
1205 if (base_path && !is_directory(base_path))
1206 die("base-path '%s' does not exist or is not a directory",
1207 base_path);
1208
1209 if (inetd_mode) {
1210 if (!freopen("/dev/null", "w", stderr))
1211 die_errno("failed to redirect stderr to /dev/null");
1212 }
1213
1214 if (inetd_mode || serve_mode)
1215 return execute();
1216
1217 if (detach) {
1218 daemonize();
1219 loginfo("Ready to rumble");
1220 }
1221 else
1222 sanitize_stdfds();
1223
1224 if (pid_file)
1225 store_pid(pid_file);
1226
1227 /* prepare argv for serving-processes */
1228 cld_argv = xmalloc(sizeof (char *) * (argc + 2));
1229 cld_argv[0] = argv[0]; /* git-daemon */
1230 cld_argv[1] = "--serve";
1231 for (i = 1; i < argc; ++i)
1232 cld_argv[i+1] = argv[i];
1233 cld_argv[argc+1] = NULL;
1234
1235 return serve(&listen_addr, listen_port, cred);
1236 }