daemon: use cld->env_array when re-spawning
[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 const char *base_path;
43 static const char *interpolated_path;
44 static int base_path_relaxed;
45
46 /* If defined, ~user notation is allowed and the string is inserted
47 * after ~user/. E.g. a request to git://host/~alice/frotz would
48 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
49 */
50 static const char *user_path;
51
52 /* Timeout, and initial timeout */
53 static unsigned int timeout;
54 static unsigned int init_timeout;
55
56 struct hostinfo {
57 struct strbuf hostname;
58 struct strbuf canon_hostname;
59 struct strbuf ip_address;
60 struct strbuf tcp_port;
61 unsigned int hostname_lookup_done:1;
62 unsigned int saw_extended_args:1;
63 };
64
65 static void lookup_hostname(struct hostinfo *hi);
66
67 static const char *get_canon_hostname(struct hostinfo *hi)
68 {
69 lookup_hostname(hi);
70 return hi->canon_hostname.buf;
71 }
72
73 static const char *get_ip_address(struct hostinfo *hi)
74 {
75 lookup_hostname(hi);
76 return hi->ip_address.buf;
77 }
78
79 static void logreport(int priority, const char *err, va_list params)
80 {
81 if (log_syslog) {
82 char buf[1024];
83 vsnprintf(buf, sizeof(buf), err, params);
84 syslog(priority, "%s", buf);
85 } else {
86 /*
87 * Since stderr is set to buffered mode, the
88 * logging of different processes will not overlap
89 * unless they overflow the (rather big) buffers.
90 */
91 fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
92 vfprintf(stderr, err, params);
93 fputc('\n', stderr);
94 fflush(stderr);
95 }
96 }
97
98 __attribute__((format (printf, 1, 2)))
99 static void logerror(const char *err, ...)
100 {
101 va_list params;
102 va_start(params, err);
103 logreport(LOG_ERR, err, params);
104 va_end(params);
105 }
106
107 __attribute__((format (printf, 1, 2)))
108 static void loginfo(const char *err, ...)
109 {
110 va_list params;
111 if (!verbose)
112 return;
113 va_start(params, err);
114 logreport(LOG_INFO, err, params);
115 va_end(params);
116 }
117
118 static void NORETURN daemon_die(const char *err, va_list params)
119 {
120 logreport(LOG_ERR, err, params);
121 exit(1);
122 }
123
124 struct expand_path_context {
125 const char *directory;
126 struct hostinfo *hostinfo;
127 };
128
129 static size_t expand_path(struct strbuf *sb, const char *placeholder, void *ctx)
130 {
131 struct expand_path_context *context = ctx;
132 struct hostinfo *hi = context->hostinfo;
133
134 switch (placeholder[0]) {
135 case 'H':
136 strbuf_addbuf(sb, &hi->hostname);
137 return 1;
138 case 'C':
139 if (placeholder[1] == 'H') {
140 strbuf_addstr(sb, get_canon_hostname(hi));
141 return 2;
142 }
143 break;
144 case 'I':
145 if (placeholder[1] == 'P') {
146 strbuf_addstr(sb, get_ip_address(hi));
147 return 2;
148 }
149 break;
150 case 'P':
151 strbuf_addbuf(sb, &hi->tcp_port);
152 return 1;
153 case 'D':
154 strbuf_addstr(sb, context->directory);
155 return 1;
156 }
157 return 0;
158 }
159
160 static const char *path_ok(const char *directory, struct hostinfo *hi)
161 {
162 static char rpath[PATH_MAX];
163 static char interp_path[PATH_MAX];
164 const char *path;
165 const char *dir;
166
167 dir = directory;
168
169 if (daemon_avoid_alias(dir)) {
170 logerror("'%s': aliased", dir);
171 return NULL;
172 }
173
174 if (*dir == '~') {
175 if (!user_path) {
176 logerror("'%s': User-path not allowed", dir);
177 return NULL;
178 }
179 if (*user_path) {
180 /* Got either "~alice" or "~alice/foo";
181 * rewrite them to "~alice/%s" or
182 * "~alice/%s/foo".
183 */
184 int namlen, restlen = strlen(dir);
185 const char *slash = strchr(dir, '/');
186 if (!slash)
187 slash = dir + restlen;
188 namlen = slash - dir;
189 restlen -= namlen;
190 loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
191 snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
192 namlen, dir, user_path, restlen, slash);
193 dir = rpath;
194 }
195 }
196 else if (interpolated_path && hi->saw_extended_args) {
197 struct strbuf expanded_path = STRBUF_INIT;
198 struct expand_path_context context;
199
200 context.directory = directory;
201 context.hostinfo = hi;
202
203 if (*dir != '/') {
204 /* Allow only absolute */
205 logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
206 return NULL;
207 }
208
209 strbuf_expand(&expanded_path, interpolated_path,
210 expand_path, &context);
211 strlcpy(interp_path, expanded_path.buf, PATH_MAX);
212 strbuf_release(&expanded_path);
213 loginfo("Interpolated dir '%s'", interp_path);
214
215 dir = interp_path;
216 }
217 else if (base_path) {
218 if (*dir != '/') {
219 /* Allow only absolute */
220 logerror("'%s': Non-absolute path denied (base-path active)", dir);
221 return NULL;
222 }
223 snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
224 dir = rpath;
225 }
226
227 path = enter_repo(dir, strict_paths);
228 if (!path && base_path && base_path_relaxed) {
229 /*
230 * if we fail and base_path_relaxed is enabled, try without
231 * prefixing the base path
232 */
233 dir = directory;
234 path = enter_repo(dir, strict_paths);
235 }
236
237 if (!path) {
238 logerror("'%s' does not appear to be a git repository", dir);
239 return NULL;
240 }
241
242 if ( ok_paths && *ok_paths ) {
243 char **pp;
244 int pathlen = strlen(path);
245
246 /* The validation is done on the paths after enter_repo
247 * appends optional {.git,.git/.git} and friends, but
248 * it does not use getcwd(). So if your /pub is
249 * a symlink to /mnt/pub, you can whitelist /pub and
250 * do not have to say /mnt/pub.
251 * Do not say /pub/.
252 */
253 for ( pp = ok_paths ; *pp ; pp++ ) {
254 int len = strlen(*pp);
255 if (len <= pathlen &&
256 !memcmp(*pp, path, len) &&
257 (path[len] == '\0' ||
258 (!strict_paths && path[len] == '/')))
259 return path;
260 }
261 }
262 else {
263 /* be backwards compatible */
264 if (!strict_paths)
265 return path;
266 }
267
268 logerror("'%s': not in whitelist", path);
269 return NULL; /* Fallthrough. Deny by default */
270 }
271
272 typedef int (*daemon_service_fn)(void);
273 struct daemon_service {
274 const char *name;
275 const char *config_name;
276 daemon_service_fn fn;
277 int enabled;
278 int overridable;
279 };
280
281 static int daemon_error(const char *dir, const char *msg)
282 {
283 if (!informative_errors)
284 msg = "access denied or repository not exported";
285 packet_write(1, "ERR %s: %s", msg, dir);
286 return -1;
287 }
288
289 static const char *access_hook;
290
291 static int run_access_hook(struct daemon_service *service, const char *dir,
292 const char *path, struct hostinfo *hi)
293 {
294 struct child_process child = CHILD_PROCESS_INIT;
295 struct strbuf buf = STRBUF_INIT;
296 const char *argv[8];
297 const char **arg = argv;
298 char *eol;
299 int seen_errors = 0;
300
301 *arg++ = access_hook;
302 *arg++ = service->name;
303 *arg++ = path;
304 *arg++ = hi->hostname.buf;
305 *arg++ = get_canon_hostname(hi);
306 *arg++ = get_ip_address(hi);
307 *arg++ = hi->tcp_port.buf;
308 *arg = NULL;
309
310 child.use_shell = 1;
311 child.argv = argv;
312 child.no_stdin = 1;
313 child.no_stderr = 1;
314 child.out = -1;
315 if (start_command(&child)) {
316 logerror("daemon access hook '%s' failed to start",
317 access_hook);
318 goto error_return;
319 }
320 if (strbuf_read(&buf, child.out, 0) < 0) {
321 logerror("failed to read from pipe to daemon access hook '%s'",
322 access_hook);
323 strbuf_reset(&buf);
324 seen_errors = 1;
325 }
326 if (close(child.out) < 0) {
327 logerror("failed to close pipe to daemon access hook '%s'",
328 access_hook);
329 seen_errors = 1;
330 }
331 if (finish_command(&child))
332 seen_errors = 1;
333
334 if (!seen_errors) {
335 strbuf_release(&buf);
336 return 0;
337 }
338
339 error_return:
340 strbuf_ltrim(&buf);
341 if (!buf.len)
342 strbuf_addstr(&buf, "service rejected");
343 eol = strchr(buf.buf, '\n');
344 if (eol)
345 *eol = '\0';
346 errno = EACCES;
347 daemon_error(dir, buf.buf);
348 strbuf_release(&buf);
349 return -1;
350 }
351
352 static int run_service(const char *dir, struct daemon_service *service,
353 struct hostinfo *hi)
354 {
355 const char *path;
356 int enabled = service->enabled;
357 struct strbuf var = STRBUF_INIT;
358
359 loginfo("Request %s for '%s'", service->name, dir);
360
361 if (!enabled && !service->overridable) {
362 logerror("'%s': service not enabled.", service->name);
363 errno = EACCES;
364 return daemon_error(dir, "service not enabled");
365 }
366
367 if (!(path = path_ok(dir, hi)))
368 return daemon_error(dir, "no such repository");
369
370 /*
371 * Security on the cheap.
372 *
373 * We want a readable HEAD, usable "objects" directory, and
374 * a "git-daemon-export-ok" flag that says that the other side
375 * is ok with us doing this.
376 *
377 * path_ok() uses enter_repo() and does whitelist checking.
378 * We only need to make sure the repository is exported.
379 */
380
381 if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
382 logerror("'%s': repository not exported.", path);
383 errno = EACCES;
384 return daemon_error(dir, "repository not exported");
385 }
386
387 if (service->overridable) {
388 strbuf_addf(&var, "daemon.%s", service->config_name);
389 git_config_get_bool(var.buf, &enabled);
390 strbuf_release(&var);
391 }
392 if (!enabled) {
393 logerror("'%s': service not enabled for '%s'",
394 service->name, path);
395 errno = EACCES;
396 return daemon_error(dir, "service not enabled");
397 }
398
399 /*
400 * Optionally, a hook can choose to deny access to the
401 * repository depending on the phase of the moon.
402 */
403 if (access_hook && run_access_hook(service, dir, path, hi))
404 return -1;
405
406 /*
407 * We'll ignore SIGTERM from now on, we have a
408 * good client.
409 */
410 signal(SIGTERM, SIG_IGN);
411
412 return service->fn();
413 }
414
415 static void copy_to_log(int fd)
416 {
417 struct strbuf line = STRBUF_INIT;
418 FILE *fp;
419
420 fp = fdopen(fd, "r");
421 if (fp == NULL) {
422 logerror("fdopen of error channel failed");
423 close(fd);
424 return;
425 }
426
427 while (strbuf_getline(&line, fp, '\n') != EOF) {
428 logerror("%s", line.buf);
429 strbuf_setlen(&line, 0);
430 }
431
432 strbuf_release(&line);
433 fclose(fp);
434 }
435
436 static int run_service_command(const char **argv)
437 {
438 struct child_process cld = CHILD_PROCESS_INIT;
439
440 cld.argv = argv;
441 cld.git_cmd = 1;
442 cld.err = -1;
443 if (start_command(&cld))
444 return -1;
445
446 close(0);
447 close(1);
448
449 copy_to_log(cld.err);
450
451 return finish_command(&cld);
452 }
453
454 static int upload_pack(void)
455 {
456 /* Timeout as string */
457 char timeout_buf[64];
458 const char *argv[] = { "upload-pack", "--strict", NULL, ".", NULL };
459
460 argv[2] = timeout_buf;
461
462 snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
463 return run_service_command(argv);
464 }
465
466 static int upload_archive(void)
467 {
468 static const char *argv[] = { "upload-archive", ".", NULL };
469 return run_service_command(argv);
470 }
471
472 static int receive_pack(void)
473 {
474 static const char *argv[] = { "receive-pack", ".", NULL };
475 return run_service_command(argv);
476 }
477
478 static struct daemon_service daemon_service[] = {
479 { "upload-archive", "uploadarch", upload_archive, 0, 1 },
480 { "upload-pack", "uploadpack", upload_pack, 1, 1 },
481 { "receive-pack", "receivepack", receive_pack, 0, 1 },
482 };
483
484 static void enable_service(const char *name, int ena)
485 {
486 int i;
487 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
488 if (!strcmp(daemon_service[i].name, name)) {
489 daemon_service[i].enabled = ena;
490 return;
491 }
492 }
493 die("No such service %s", name);
494 }
495
496 static void make_service_overridable(const char *name, int ena)
497 {
498 int i;
499 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
500 if (!strcmp(daemon_service[i].name, name)) {
501 daemon_service[i].overridable = ena;
502 return;
503 }
504 }
505 die("No such service %s", name);
506 }
507
508 static void parse_host_and_port(char *hostport, char **host,
509 char **port)
510 {
511 if (*hostport == '[') {
512 char *end;
513
514 end = strchr(hostport, ']');
515 if (!end)
516 die("Invalid request ('[' without ']')");
517 *end = '\0';
518 *host = hostport + 1;
519 if (!end[1])
520 *port = NULL;
521 else if (end[1] == ':')
522 *port = end + 2;
523 else
524 die("Garbage after end of host part");
525 } else {
526 *host = hostport;
527 *port = strrchr(hostport, ':');
528 if (*port) {
529 **port = '\0';
530 ++*port;
531 }
532 }
533 }
534
535 /*
536 * Sanitize a string from the client so that it's OK to be inserted into a
537 * filesystem path. Specifically, we disallow slashes, runs of "..", and
538 * trailing and leading dots, which means that the client cannot escape
539 * our base path via ".." traversal.
540 */
541 static void sanitize_client(struct strbuf *out, const char *in)
542 {
543 for (; *in; in++) {
544 if (*in == '/')
545 continue;
546 if (*in == '.' && (!out->len || out->buf[out->len - 1] == '.'))
547 continue;
548 strbuf_addch(out, *in);
549 }
550
551 while (out->len && out->buf[out->len - 1] == '.')
552 strbuf_setlen(out, out->len - 1);
553 }
554
555 /*
556 * Like sanitize_client, but we also perform any canonicalization
557 * to make life easier on the admin.
558 */
559 static void canonicalize_client(struct strbuf *out, const char *in)
560 {
561 sanitize_client(out, in);
562 strbuf_tolower(out);
563 }
564
565 /*
566 * Read the host as supplied by the client connection.
567 */
568 static void parse_host_arg(struct hostinfo *hi, char *extra_args, int buflen)
569 {
570 char *val;
571 int vallen;
572 char *end = extra_args + buflen;
573
574 if (extra_args < end && *extra_args) {
575 hi->saw_extended_args = 1;
576 if (strncasecmp("host=", extra_args, 5) == 0) {
577 val = extra_args + 5;
578 vallen = strlen(val) + 1;
579 if (*val) {
580 /* Split <host>:<port> at colon. */
581 char *host;
582 char *port;
583 parse_host_and_port(val, &host, &port);
584 if (port)
585 sanitize_client(&hi->tcp_port, port);
586 canonicalize_client(&hi->hostname, host);
587 hi->hostname_lookup_done = 0;
588 }
589
590 /* On to the next one */
591 extra_args = val + vallen;
592 }
593 if (extra_args < end && *extra_args)
594 die("Invalid request");
595 }
596 }
597
598 /*
599 * Locate canonical hostname and its IP address.
600 */
601 static void lookup_hostname(struct hostinfo *hi)
602 {
603 if (!hi->hostname_lookup_done && hi->hostname.len) {
604 #ifndef NO_IPV6
605 struct addrinfo hints;
606 struct addrinfo *ai;
607 int gai;
608 static char addrbuf[HOST_NAME_MAX + 1];
609
610 memset(&hints, 0, sizeof(hints));
611 hints.ai_flags = AI_CANONNAME;
612
613 gai = getaddrinfo(hi->hostname.buf, NULL, &hints, &ai);
614 if (!gai) {
615 struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
616
617 inet_ntop(AF_INET, &sin_addr->sin_addr,
618 addrbuf, sizeof(addrbuf));
619 strbuf_addstr(&hi->ip_address, addrbuf);
620
621 if (ai->ai_canonname)
622 sanitize_client(&hi->canon_hostname,
623 ai->ai_canonname);
624 else
625 strbuf_addbuf(&hi->canon_hostname,
626 &hi->ip_address);
627
628 freeaddrinfo(ai);
629 }
630 #else
631 struct hostent *hent;
632 struct sockaddr_in sa;
633 char **ap;
634 static char addrbuf[HOST_NAME_MAX + 1];
635
636 hent = gethostbyname(hi->hostname.buf);
637 if (hent) {
638 ap = hent->h_addr_list;
639 memset(&sa, 0, sizeof sa);
640 sa.sin_family = hent->h_addrtype;
641 sa.sin_port = htons(0);
642 memcpy(&sa.sin_addr, *ap, hent->h_length);
643
644 inet_ntop(hent->h_addrtype, &sa.sin_addr,
645 addrbuf, sizeof(addrbuf));
646
647 sanitize_client(&hi->canon_hostname, hent->h_name);
648 strbuf_addstr(&hi->ip_address, addrbuf);
649 }
650 #endif
651 hi->hostname_lookup_done = 1;
652 }
653 }
654
655 static void hostinfo_init(struct hostinfo *hi)
656 {
657 memset(hi, 0, sizeof(*hi));
658 strbuf_init(&hi->hostname, 0);
659 strbuf_init(&hi->canon_hostname, 0);
660 strbuf_init(&hi->ip_address, 0);
661 strbuf_init(&hi->tcp_port, 0);
662 }
663
664 static void hostinfo_clear(struct hostinfo *hi)
665 {
666 strbuf_release(&hi->hostname);
667 strbuf_release(&hi->canon_hostname);
668 strbuf_release(&hi->ip_address);
669 strbuf_release(&hi->tcp_port);
670 }
671
672 static int execute(void)
673 {
674 char *line = packet_buffer;
675 int pktlen, len, i;
676 char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
677 struct hostinfo hi;
678
679 hostinfo_init(&hi);
680
681 if (addr)
682 loginfo("Connection from %s:%s", addr, port);
683
684 alarm(init_timeout ? init_timeout : timeout);
685 pktlen = packet_read(0, NULL, NULL, packet_buffer, sizeof(packet_buffer), 0);
686 alarm(0);
687
688 len = strlen(line);
689 if (pktlen != len)
690 loginfo("Extended attributes (%d bytes) exist <%.*s>",
691 (int) pktlen - len,
692 (int) pktlen - len, line + len + 1);
693 if (len && line[len-1] == '\n') {
694 line[--len] = 0;
695 pktlen--;
696 }
697
698 if (len != pktlen)
699 parse_host_arg(&hi, line + len + 1, pktlen - len - 1);
700
701 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
702 struct daemon_service *s = &(daemon_service[i]);
703 const char *arg;
704
705 if (skip_prefix(line, "git-", &arg) &&
706 skip_prefix(arg, s->name, &arg) &&
707 *arg++ == ' ') {
708 /*
709 * Note: The directory here is probably context sensitive,
710 * and might depend on the actual service being performed.
711 */
712 int rc = run_service(arg, s, &hi);
713 hostinfo_clear(&hi);
714 return rc;
715 }
716 }
717
718 hostinfo_clear(&hi);
719 logerror("Protocol error: '%s'", line);
720 return -1;
721 }
722
723 static int addrcmp(const struct sockaddr_storage *s1,
724 const struct sockaddr_storage *s2)
725 {
726 const struct sockaddr *sa1 = (const struct sockaddr*) s1;
727 const struct sockaddr *sa2 = (const struct sockaddr*) s2;
728
729 if (sa1->sa_family != sa2->sa_family)
730 return sa1->sa_family - sa2->sa_family;
731 if (sa1->sa_family == AF_INET)
732 return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
733 &((struct sockaddr_in *)s2)->sin_addr,
734 sizeof(struct in_addr));
735 #ifndef NO_IPV6
736 if (sa1->sa_family == AF_INET6)
737 return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
738 &((struct sockaddr_in6 *)s2)->sin6_addr,
739 sizeof(struct in6_addr));
740 #endif
741 return 0;
742 }
743
744 static int max_connections = 32;
745
746 static unsigned int live_children;
747
748 static struct child {
749 struct child *next;
750 struct child_process cld;
751 struct sockaddr_storage address;
752 } *firstborn;
753
754 static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
755 {
756 struct child *newborn, **cradle;
757
758 newborn = xcalloc(1, sizeof(*newborn));
759 live_children++;
760 memcpy(&newborn->cld, cld, sizeof(*cld));
761 memcpy(&newborn->address, addr, addrlen);
762 for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
763 if (!addrcmp(&(*cradle)->address, &newborn->address))
764 break;
765 newborn->next = *cradle;
766 *cradle = newborn;
767 }
768
769 /*
770 * This gets called if the number of connections grows
771 * past "max_connections".
772 *
773 * We kill the newest connection from a duplicate IP.
774 */
775 static void kill_some_child(void)
776 {
777 const struct child *blanket, *next;
778
779 if (!(blanket = firstborn))
780 return;
781
782 for (; (next = blanket->next); blanket = next)
783 if (!addrcmp(&blanket->address, &next->address)) {
784 kill(blanket->cld.pid, SIGTERM);
785 break;
786 }
787 }
788
789 static void check_dead_children(void)
790 {
791 int status;
792 pid_t pid;
793
794 struct child **cradle, *blanket;
795 for (cradle = &firstborn; (blanket = *cradle);)
796 if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
797 const char *dead = "";
798 if (status)
799 dead = " (with error)";
800 loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
801
802 /* remove the child */
803 *cradle = blanket->next;
804 live_children--;
805 free(blanket);
806 } else
807 cradle = &blanket->next;
808 }
809
810 static char **cld_argv;
811 static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
812 {
813 struct child_process cld = CHILD_PROCESS_INIT;
814
815 if (max_connections && live_children >= max_connections) {
816 kill_some_child();
817 sleep(1); /* give it some time to die */
818 check_dead_children();
819 if (live_children >= max_connections) {
820 close(incoming);
821 logerror("Too many children, dropping connection");
822 return;
823 }
824 }
825
826 if (addr->sa_family == AF_INET) {
827 char buf[128] = "";
828 struct sockaddr_in *sin_addr = (void *) addr;
829 inet_ntop(addr->sa_family, &sin_addr->sin_addr, buf, sizeof(buf));
830 argv_array_pushf(&cld.env_array, "REMOTE_ADDR=%s", buf);
831 argv_array_pushf(&cld.env_array, "REMOTE_PORT=%d",
832 ntohs(sin_addr->sin_port));
833 #ifndef NO_IPV6
834 } else if (addr->sa_family == AF_INET6) {
835 char buf[128] = "";
836 struct sockaddr_in6 *sin6_addr = (void *) addr;
837 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(buf));
838 argv_array_pushf(&cld.env_array, "REMOTE_ADDR=[%s]", buf);
839 argv_array_pushf(&cld.env_array, "REMOTE_PORT=%d",
840 ntohs(sin6_addr->sin6_port));
841 #endif
842 }
843
844 cld.argv = (const char **)cld_argv;
845 cld.in = incoming;
846 cld.out = dup(incoming);
847
848 if (start_command(&cld))
849 logerror("unable to fork");
850 else
851 add_child(&cld, addr, addrlen);
852 }
853
854 static void child_handler(int signo)
855 {
856 /*
857 * Otherwise empty handler because systemcalls will get interrupted
858 * upon signal receipt
859 * SysV needs the handler to be rearmed
860 */
861 signal(SIGCHLD, child_handler);
862 }
863
864 static int set_reuse_addr(int sockfd)
865 {
866 int on = 1;
867
868 if (!reuseaddr)
869 return 0;
870 return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
871 &on, sizeof(on));
872 }
873
874 struct socketlist {
875 int *list;
876 size_t nr;
877 size_t alloc;
878 };
879
880 static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
881 {
882 #ifdef NO_IPV6
883 static char ip[INET_ADDRSTRLEN];
884 #else
885 static char ip[INET6_ADDRSTRLEN];
886 #endif
887
888 switch (family) {
889 #ifndef NO_IPV6
890 case AF_INET6:
891 inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
892 break;
893 #endif
894 case AF_INET:
895 inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
896 break;
897 default:
898 xsnprintf(ip, sizeof(ip), "<unknown>");
899 }
900 return ip;
901 }
902
903 #ifndef NO_IPV6
904
905 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
906 {
907 int socknum = 0;
908 char pbuf[NI_MAXSERV];
909 struct addrinfo hints, *ai0, *ai;
910 int gai;
911 long flags;
912
913 xsnprintf(pbuf, sizeof(pbuf), "%d", listen_port);
914 memset(&hints, 0, sizeof(hints));
915 hints.ai_family = AF_UNSPEC;
916 hints.ai_socktype = SOCK_STREAM;
917 hints.ai_protocol = IPPROTO_TCP;
918 hints.ai_flags = AI_PASSIVE;
919
920 gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
921 if (gai) {
922 logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
923 return 0;
924 }
925
926 for (ai = ai0; ai; ai = ai->ai_next) {
927 int sockfd;
928
929 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
930 if (sockfd < 0)
931 continue;
932 if (sockfd >= FD_SETSIZE) {
933 logerror("Socket descriptor too large");
934 close(sockfd);
935 continue;
936 }
937
938 #ifdef IPV6_V6ONLY
939 if (ai->ai_family == AF_INET6) {
940 int on = 1;
941 setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
942 &on, sizeof(on));
943 /* Note: error is not fatal */
944 }
945 #endif
946
947 if (set_reuse_addr(sockfd)) {
948 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
949 close(sockfd);
950 continue;
951 }
952
953 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
954 logerror("Could not bind to %s: %s",
955 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
956 strerror(errno));
957 close(sockfd);
958 continue; /* not fatal */
959 }
960 if (listen(sockfd, 5) < 0) {
961 logerror("Could not listen to %s: %s",
962 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
963 strerror(errno));
964 close(sockfd);
965 continue; /* not fatal */
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 socknum++;
975 }
976
977 freeaddrinfo(ai0);
978
979 return socknum;
980 }
981
982 #else /* NO_IPV6 */
983
984 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
985 {
986 struct sockaddr_in sin;
987 int sockfd;
988 long flags;
989
990 memset(&sin, 0, sizeof sin);
991 sin.sin_family = AF_INET;
992 sin.sin_port = htons(listen_port);
993
994 if (listen_addr) {
995 /* Well, host better be an IP address here. */
996 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
997 return 0;
998 } else {
999 sin.sin_addr.s_addr = htonl(INADDR_ANY);
1000 }
1001
1002 sockfd = socket(AF_INET, SOCK_STREAM, 0);
1003 if (sockfd < 0)
1004 return 0;
1005
1006 if (set_reuse_addr(sockfd)) {
1007 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1008 close(sockfd);
1009 return 0;
1010 }
1011
1012 if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
1013 logerror("Could not bind to %s: %s",
1014 ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1015 strerror(errno));
1016 close(sockfd);
1017 return 0;
1018 }
1019
1020 if (listen(sockfd, 5) < 0) {
1021 logerror("Could not listen to %s: %s",
1022 ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1023 strerror(errno));
1024 close(sockfd);
1025 return 0;
1026 }
1027
1028 flags = fcntl(sockfd, F_GETFD, 0);
1029 if (flags >= 0)
1030 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1031
1032 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1033 socklist->list[socklist->nr++] = sockfd;
1034 return 1;
1035 }
1036
1037 #endif
1038
1039 static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
1040 {
1041 if (!listen_addr->nr)
1042 setup_named_sock(NULL, listen_port, socklist);
1043 else {
1044 int i, socknum;
1045 for (i = 0; i < listen_addr->nr; i++) {
1046 socknum = setup_named_sock(listen_addr->items[i].string,
1047 listen_port, socklist);
1048
1049 if (socknum == 0)
1050 logerror("unable to allocate any listen sockets for host %s on port %u",
1051 listen_addr->items[i].string, listen_port);
1052 }
1053 }
1054 }
1055
1056 static int service_loop(struct socketlist *socklist)
1057 {
1058 struct pollfd *pfd;
1059 int i;
1060
1061 pfd = xcalloc(socklist->nr, sizeof(struct pollfd));
1062
1063 for (i = 0; i < socklist->nr; i++) {
1064 pfd[i].fd = socklist->list[i];
1065 pfd[i].events = POLLIN;
1066 }
1067
1068 signal(SIGCHLD, child_handler);
1069
1070 for (;;) {
1071 int i;
1072
1073 check_dead_children();
1074
1075 if (poll(pfd, socklist->nr, -1) < 0) {
1076 if (errno != EINTR) {
1077 logerror("Poll failed, resuming: %s",
1078 strerror(errno));
1079 sleep(1);
1080 }
1081 continue;
1082 }
1083
1084 for (i = 0; i < socklist->nr; i++) {
1085 if (pfd[i].revents & POLLIN) {
1086 union {
1087 struct sockaddr sa;
1088 struct sockaddr_in sai;
1089 #ifndef NO_IPV6
1090 struct sockaddr_in6 sai6;
1091 #endif
1092 } ss;
1093 socklen_t sslen = sizeof(ss);
1094 int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1095 if (incoming < 0) {
1096 switch (errno) {
1097 case EAGAIN:
1098 case EINTR:
1099 case ECONNABORTED:
1100 continue;
1101 default:
1102 die_errno("accept returned");
1103 }
1104 }
1105 handle(incoming, &ss.sa, sslen);
1106 }
1107 }
1108 }
1109 }
1110
1111 #ifdef NO_POSIX_GOODIES
1112
1113 struct credentials;
1114
1115 static void drop_privileges(struct credentials *cred)
1116 {
1117 /* nothing */
1118 }
1119
1120 static struct credentials *prepare_credentials(const char *user_name,
1121 const char *group_name)
1122 {
1123 die("--user not supported on this platform");
1124 }
1125
1126 #else
1127
1128 struct credentials {
1129 struct passwd *pass;
1130 gid_t gid;
1131 };
1132
1133 static void drop_privileges(struct credentials *cred)
1134 {
1135 if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1136 setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1137 die("cannot drop privileges");
1138 }
1139
1140 static struct credentials *prepare_credentials(const char *user_name,
1141 const char *group_name)
1142 {
1143 static struct credentials c;
1144
1145 c.pass = getpwnam(user_name);
1146 if (!c.pass)
1147 die("user not found - %s", user_name);
1148
1149 if (!group_name)
1150 c.gid = c.pass->pw_gid;
1151 else {
1152 struct group *group = getgrnam(group_name);
1153 if (!group)
1154 die("group not found - %s", group_name);
1155
1156 c.gid = group->gr_gid;
1157 }
1158
1159 return &c;
1160 }
1161 #endif
1162
1163 static int serve(struct string_list *listen_addr, int listen_port,
1164 struct credentials *cred)
1165 {
1166 struct socketlist socklist = { NULL, 0, 0 };
1167
1168 socksetup(listen_addr, listen_port, &socklist);
1169 if (socklist.nr == 0)
1170 die("unable to allocate any listen sockets on port %u",
1171 listen_port);
1172
1173 drop_privileges(cred);
1174
1175 loginfo("Ready to rumble");
1176
1177 return service_loop(&socklist);
1178 }
1179
1180 int main(int argc, char **argv)
1181 {
1182 int listen_port = 0;
1183 struct string_list listen_addr = STRING_LIST_INIT_NODUP;
1184 int serve_mode = 0, inetd_mode = 0;
1185 const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1186 int detach = 0;
1187 struct credentials *cred = NULL;
1188 int i;
1189
1190 git_setup_gettext();
1191
1192 git_extract_argv0_path(argv[0]);
1193
1194 for (i = 1; i < argc; i++) {
1195 char *arg = argv[i];
1196 const char *v;
1197
1198 if (skip_prefix(arg, "--listen=", &v)) {
1199 string_list_append(&listen_addr, xstrdup_tolower(v));
1200 continue;
1201 }
1202 if (skip_prefix(arg, "--port=", &v)) {
1203 char *end;
1204 unsigned long n;
1205 n = strtoul(v, &end, 0);
1206 if (*v && !*end) {
1207 listen_port = n;
1208 continue;
1209 }
1210 }
1211 if (!strcmp(arg, "--serve")) {
1212 serve_mode = 1;
1213 continue;
1214 }
1215 if (!strcmp(arg, "--inetd")) {
1216 inetd_mode = 1;
1217 log_syslog = 1;
1218 continue;
1219 }
1220 if (!strcmp(arg, "--verbose")) {
1221 verbose = 1;
1222 continue;
1223 }
1224 if (!strcmp(arg, "--syslog")) {
1225 log_syslog = 1;
1226 continue;
1227 }
1228 if (!strcmp(arg, "--export-all")) {
1229 export_all_trees = 1;
1230 continue;
1231 }
1232 if (skip_prefix(arg, "--access-hook=", &v)) {
1233 access_hook = v;
1234 continue;
1235 }
1236 if (skip_prefix(arg, "--timeout=", &v)) {
1237 timeout = atoi(v);
1238 continue;
1239 }
1240 if (skip_prefix(arg, "--init-timeout=", &v)) {
1241 init_timeout = atoi(v);
1242 continue;
1243 }
1244 if (skip_prefix(arg, "--max-connections=", &v)) {
1245 max_connections = atoi(v);
1246 if (max_connections < 0)
1247 max_connections = 0; /* unlimited */
1248 continue;
1249 }
1250 if (!strcmp(arg, "--strict-paths")) {
1251 strict_paths = 1;
1252 continue;
1253 }
1254 if (skip_prefix(arg, "--base-path=", &v)) {
1255 base_path = v;
1256 continue;
1257 }
1258 if (!strcmp(arg, "--base-path-relaxed")) {
1259 base_path_relaxed = 1;
1260 continue;
1261 }
1262 if (skip_prefix(arg, "--interpolated-path=", &v)) {
1263 interpolated_path = v;
1264 continue;
1265 }
1266 if (!strcmp(arg, "--reuseaddr")) {
1267 reuseaddr = 1;
1268 continue;
1269 }
1270 if (!strcmp(arg, "--user-path")) {
1271 user_path = "";
1272 continue;
1273 }
1274 if (skip_prefix(arg, "--user-path=", &v)) {
1275 user_path = v;
1276 continue;
1277 }
1278 if (skip_prefix(arg, "--pid-file=", &v)) {
1279 pid_file = v;
1280 continue;
1281 }
1282 if (!strcmp(arg, "--detach")) {
1283 detach = 1;
1284 log_syslog = 1;
1285 continue;
1286 }
1287 if (skip_prefix(arg, "--user=", &v)) {
1288 user_name = v;
1289 continue;
1290 }
1291 if (skip_prefix(arg, "--group=", &v)) {
1292 group_name = v;
1293 continue;
1294 }
1295 if (skip_prefix(arg, "--enable=", &v)) {
1296 enable_service(v, 1);
1297 continue;
1298 }
1299 if (skip_prefix(arg, "--disable=", &v)) {
1300 enable_service(v, 0);
1301 continue;
1302 }
1303 if (skip_prefix(arg, "--allow-override=", &v)) {
1304 make_service_overridable(v, 1);
1305 continue;
1306 }
1307 if (skip_prefix(arg, "--forbid-override=", &v)) {
1308 make_service_overridable(v, 0);
1309 continue;
1310 }
1311 if (!strcmp(arg, "--informative-errors")) {
1312 informative_errors = 1;
1313 continue;
1314 }
1315 if (!strcmp(arg, "--no-informative-errors")) {
1316 informative_errors = 0;
1317 continue;
1318 }
1319 if (!strcmp(arg, "--")) {
1320 ok_paths = &argv[i+1];
1321 break;
1322 } else if (arg[0] != '-') {
1323 ok_paths = &argv[i];
1324 break;
1325 }
1326
1327 usage(daemon_usage);
1328 }
1329
1330 if (log_syslog) {
1331 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1332 set_die_routine(daemon_die);
1333 } else
1334 /* avoid splitting a message in the middle */
1335 setvbuf(stderr, NULL, _IOFBF, 4096);
1336
1337 if (inetd_mode && (detach || group_name || user_name))
1338 die("--detach, --user and --group are incompatible with --inetd");
1339
1340 if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1341 die("--listen= and --port= are incompatible with --inetd");
1342 else if (listen_port == 0)
1343 listen_port = DEFAULT_GIT_PORT;
1344
1345 if (group_name && !user_name)
1346 die("--group supplied without --user");
1347
1348 if (user_name)
1349 cred = prepare_credentials(user_name, group_name);
1350
1351 if (strict_paths && (!ok_paths || !*ok_paths))
1352 die("option --strict-paths requires a whitelist");
1353
1354 if (base_path && !is_directory(base_path))
1355 die("base-path '%s' does not exist or is not a directory",
1356 base_path);
1357
1358 if (inetd_mode) {
1359 if (!freopen("/dev/null", "w", stderr))
1360 die_errno("failed to redirect stderr to /dev/null");
1361 }
1362
1363 if (inetd_mode || serve_mode)
1364 return execute();
1365
1366 if (detach) {
1367 if (daemonize())
1368 die("--detach not supported on this platform");
1369 } else
1370 sanitize_stdfds();
1371
1372 if (pid_file)
1373 write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
1374
1375 /* prepare argv for serving-processes */
1376 cld_argv = xmalloc(sizeof (char *) * (argc + 2));
1377 cld_argv[0] = argv[0]; /* git-daemon */
1378 cld_argv[1] = "--serve";
1379 for (i = 1; i < argc; ++i)
1380 cld_argv[i+1] = argv[i];
1381 cld_argv[argc+1] = NULL;
1382
1383 return serve(&listen_addr, listen_port, cred);
1384 }