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fetch-pack: in partial clone, pass --promisor
[git.git] / daemon.c
blob2ab7ea82eb0b4f7c62c553e1e65c16644983f7de
1 #include "cache.h"
2 #include "config.h"
3 #include "pkt-line.h"
4 #include "run-command.h"
5 #include "strbuf.h"
6 #include "string-list.h"
7
8 #ifdef NO_INITGROUPS
9 #define initgroups(x, y) (0) /* nothing */
10 #endif
11
12 static enum log_destination {
13 LOG_DESTINATION_UNSET = -1,
14 LOG_DESTINATION_NONE = 0,
15 LOG_DESTINATION_STDERR = 1,
16 LOG_DESTINATION_SYSLOG = 2,
17 } log_destination = LOG_DESTINATION_UNSET;
18 static int verbose;
19 static int reuseaddr;
20 static int informative_errors;
21
22 static const char daemon_usage[] =
23 "git daemon [--verbose] [--syslog] [--export-all]\n"
24 " [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n"
25 " [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
26 " [--user-path | --user-path=<path>]\n"
27 " [--interpolated-path=<path>]\n"
28 " [--reuseaddr] [--pid-file=<file>]\n"
29 " [--(enable|disable|allow-override|forbid-override)=<service>]\n"
30 " [--access-hook=<path>]\n"
31 " [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
32 " [--detach] [--user=<user> [--group=<group>]]\n"
33 " [--log-destination=(stderr|syslog|none)]\n"
34 " [<directory>...]";
35
36 /* List of acceptable pathname prefixes */
37 static const 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 const char *base_path;
45 static const char *interpolated_path;
46 static int base_path_relaxed;
47
48 /* If defined, ~user notation is allowed and the string is inserted
49 * after ~user/. E.g. a request to git://host/~alice/frotz would
50 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
51 */
52 static const char *user_path;
53
54 /* Timeout, and initial timeout */
55 static unsigned int timeout;
56 static unsigned int init_timeout;
57
58 struct hostinfo {
59 struct strbuf hostname;
60 struct strbuf canon_hostname;
61 struct strbuf ip_address;
62 struct strbuf tcp_port;
63 unsigned int hostname_lookup_done:1;
64 unsigned int saw_extended_args:1;
65 };
66
67 static void lookup_hostname(struct hostinfo *hi);
68
69 static const char *get_canon_hostname(struct hostinfo *hi)
70 {
71 lookup_hostname(hi);
72 return hi->canon_hostname.buf;
73 }
74
75 static const char *get_ip_address(struct hostinfo *hi)
76 {
77 lookup_hostname(hi);
78 return hi->ip_address.buf;
79 }
80
81 static void logreport(int priority, const char *err, va_list params)
82 {
83 switch (log_destination) {
84 case LOG_DESTINATION_SYSLOG: {
85 char buf[1024];
86 vsnprintf(buf, sizeof(buf), err, params);
87 syslog(priority, "%s", buf);
88 break;
89 }
90 case LOG_DESTINATION_STDERR:
91 /*
92 * Since stderr is set to buffered mode, the
93 * logging of different processes will not overlap
94 * unless they overflow the (rather big) buffers.
95 */
96 fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
97 vfprintf(stderr, err, params);
98 fputc('\n', stderr);
99 fflush(stderr);
100 break;
101 case LOG_DESTINATION_NONE:
102 break;
103 case LOG_DESTINATION_UNSET:
104 BUG("log destination not initialized correctly");
105 }
106 }
107
108 __attribute__((format (printf, 1, 2)))
109 static void logerror(const char *err, ...)
110 {
111 va_list params;
112 va_start(params, err);
113 logreport(LOG_ERR, err, params);
114 va_end(params);
115 }
116
117 __attribute__((format (printf, 1, 2)))
118 static void loginfo(const char *err, ...)
119 {
120 va_list params;
121 if (!verbose)
122 return;
123 va_start(params, err);
124 logreport(LOG_INFO, err, params);
125 va_end(params);
126 }
127
128 static void NORETURN daemon_die(const char *err, va_list params)
129 {
130 logreport(LOG_ERR, err, params);
131 exit(1);
132 }
133
134 struct expand_path_context {
135 const char *directory;
136 struct hostinfo *hostinfo;
137 };
138
139 static size_t expand_path(struct strbuf *sb, const char *placeholder, void *ctx)
140 {
141 struct expand_path_context *context = ctx;
142 struct hostinfo *hi = context->hostinfo;
143
144 switch (placeholder[0]) {
145 case 'H':
146 strbuf_addbuf(sb, &hi->hostname);
147 return 1;
148 case 'C':
149 if (placeholder[1] == 'H') {
150 strbuf_addstr(sb, get_canon_hostname(hi));
151 return 2;
152 }
153 break;
154 case 'I':
155 if (placeholder[1] == 'P') {
156 strbuf_addstr(sb, get_ip_address(hi));
157 return 2;
158 }
159 break;
160 case 'P':
161 strbuf_addbuf(sb, &hi->tcp_port);
162 return 1;
163 case 'D':
164 strbuf_addstr(sb, context->directory);
165 return 1;
166 }
167 return 0;
168 }
169
170 static const char *path_ok(const char *directory, struct hostinfo *hi)
171 {
172 static char rpath[PATH_MAX];
173 static char interp_path[PATH_MAX];
174 size_t rlen;
175 const char *path;
176 const char *dir;
177
178 dir = directory;
179
180 if (daemon_avoid_alias(dir)) {
181 logerror("'%s': aliased", dir);
182 return NULL;
183 }
184
185 if (*dir == '~') {
186 if (!user_path) {
187 logerror("'%s': User-path not allowed", dir);
188 return NULL;
189 }
190 if (*user_path) {
191 /* Got either "~alice" or "~alice/foo";
192 * rewrite them to "~alice/%s" or
193 * "~alice/%s/foo".
194 */
195 int namlen, restlen = strlen(dir);
196 const char *slash = strchr(dir, '/');
197 if (!slash)
198 slash = dir + restlen;
199 namlen = slash - dir;
200 restlen -= namlen;
201 loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
202 rlen = snprintf(rpath, sizeof(rpath), "%.*s/%s%.*s",
203 namlen, dir, user_path, restlen, slash);
204 if (rlen >= sizeof(rpath)) {
205 logerror("user-path too large: %s", rpath);
206 return NULL;
207 }
208 dir = rpath;
209 }
210 }
211 else if (interpolated_path && hi->saw_extended_args) {
212 struct strbuf expanded_path = STRBUF_INIT;
213 struct expand_path_context context;
214
215 context.directory = directory;
216 context.hostinfo = hi;
217
218 if (*dir != '/') {
219 /* Allow only absolute */
220 logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
221 return NULL;
222 }
223
224 strbuf_expand(&expanded_path, interpolated_path,
225 expand_path, &context);
226
227 rlen = strlcpy(interp_path, expanded_path.buf,
228 sizeof(interp_path));
229 if (rlen >= sizeof(interp_path)) {
230 logerror("interpolated path too large: %s",
231 interp_path);
232 return NULL;
233 }
234
235 strbuf_release(&expanded_path);
236 loginfo("Interpolated dir '%s'", interp_path);
237
238 dir = interp_path;
239 }
240 else if (base_path) {
241 if (*dir != '/') {
242 /* Allow only absolute */
243 logerror("'%s': Non-absolute path denied (base-path active)", dir);
244 return NULL;
245 }
246 rlen = snprintf(rpath, sizeof(rpath), "%s%s", base_path, dir);
247 if (rlen >= sizeof(rpath)) {
248 logerror("base-path too large: %s", rpath);
249 return NULL;
250 }
251 dir = rpath;
252 }
253
254 path = enter_repo(dir, strict_paths);
255 if (!path && base_path && base_path_relaxed) {
256 /*
257 * if we fail and base_path_relaxed is enabled, try without
258 * prefixing the base path
259 */
260 dir = directory;
261 path = enter_repo(dir, strict_paths);
262 }
263
264 if (!path) {
265 logerror("'%s' does not appear to be a git repository", dir);
266 return NULL;
267 }
268
269 if ( ok_paths && *ok_paths ) {
270 const char **pp;
271 int pathlen = strlen(path);
272
273 /* The validation is done on the paths after enter_repo
274 * appends optional {.git,.git/.git} and friends, but
275 * it does not use getcwd(). So if your /pub is
276 * a symlink to /mnt/pub, you can whitelist /pub and
277 * do not have to say /mnt/pub.
278 * Do not say /pub/.
279 */
280 for ( pp = ok_paths ; *pp ; pp++ ) {
281 int len = strlen(*pp);
282 if (len <= pathlen &&
283 !memcmp(*pp, path, len) &&
284 (path[len] == '\0' ||
285 (!strict_paths && path[len] == '/')))
286 return path;
287 }
288 }
289 else {
290 /* be backwards compatible */
291 if (!strict_paths)
292 return path;
293 }
294
295 logerror("'%s': not in whitelist", path);
296 return NULL; /* Fallthrough. Deny by default */
297 }
298
299 typedef int (*daemon_service_fn)(const struct strvec *env);
300 struct daemon_service {
301 const char *name;
302 const char *config_name;
303 daemon_service_fn fn;
304 int enabled;
305 int overridable;
306 };
307
308 static int daemon_error(const char *dir, const char *msg)
309 {
310 if (!informative_errors)
311 msg = "access denied or repository not exported";
312 packet_write_fmt(1, "ERR %s: %s", msg, dir);
313 return -1;
314 }
315
316 static const char *access_hook;
317
318 static int run_access_hook(struct daemon_service *service, const char *dir,
319 const char *path, struct hostinfo *hi)
320 {
321 struct child_process child = CHILD_PROCESS_INIT;
322 struct strbuf buf = STRBUF_INIT;
323 const char *argv[8];
324 const char **arg = argv;
325 char *eol;
326 int seen_errors = 0;
327
328 *arg++ = access_hook;
329 *arg++ = service->name;
330 *arg++ = path;
331 *arg++ = hi->hostname.buf;
332 *arg++ = get_canon_hostname(hi);
333 *arg++ = get_ip_address(hi);
334 *arg++ = hi->tcp_port.buf;
335 *arg = NULL;
336
337 child.use_shell = 1;
338 child.argv = argv;
339 child.no_stdin = 1;
340 child.no_stderr = 1;
341 child.out = -1;
342 if (start_command(&child)) {
343 logerror("daemon access hook '%s' failed to start",
344 access_hook);
345 goto error_return;
346 }
347 if (strbuf_read(&buf, child.out, 0) < 0) {
348 logerror("failed to read from pipe to daemon access hook '%s'",
349 access_hook);
350 strbuf_reset(&buf);
351 seen_errors = 1;
352 }
353 if (close(child.out) < 0) {
354 logerror("failed to close pipe to daemon access hook '%s'",
355 access_hook);
356 seen_errors = 1;
357 }
358 if (finish_command(&child))
359 seen_errors = 1;
360
361 if (!seen_errors) {
362 strbuf_release(&buf);
363 return 0;
364 }
365
366 error_return:
367 strbuf_ltrim(&buf);
368 if (!buf.len)
369 strbuf_addstr(&buf, "service rejected");
370 eol = strchr(buf.buf, '\n');
371 if (eol)
372 *eol = '\0';
373 errno = EACCES;
374 daemon_error(dir, buf.buf);
375 strbuf_release(&buf);
376 return -1;
377 }
378
379 static int run_service(const char *dir, struct daemon_service *service,
380 struct hostinfo *hi, const struct strvec *env)
381 {
382 const char *path;
383 int enabled = service->enabled;
384 struct strbuf var = STRBUF_INIT;
385
386 loginfo("Request %s for '%s'", service->name, dir);
387
388 if (!enabled && !service->overridable) {
389 logerror("'%s': service not enabled.", service->name);
390 errno = EACCES;
391 return daemon_error(dir, "service not enabled");
392 }
393
394 if (!(path = path_ok(dir, hi)))
395 return daemon_error(dir, "no such repository");
396
397 /*
398 * Security on the cheap.
399 *
400 * We want a readable HEAD, usable "objects" directory, and
401 * a "git-daemon-export-ok" flag that says that the other side
402 * is ok with us doing this.
403 *
404 * path_ok() uses enter_repo() and does whitelist checking.
405 * We only need to make sure the repository is exported.
406 */
407
408 if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
409 logerror("'%s': repository not exported.", path);
410 errno = EACCES;
411 return daemon_error(dir, "repository not exported");
412 }
413
414 if (service->overridable) {
415 strbuf_addf(&var, "daemon.%s", service->config_name);
416 git_config_get_bool(var.buf, &enabled);
417 strbuf_release(&var);
418 }
419 if (!enabled) {
420 logerror("'%s': service not enabled for '%s'",
421 service->name, path);
422 errno = EACCES;
423 return daemon_error(dir, "service not enabled");
424 }
425
426 /*
427 * Optionally, a hook can choose to deny access to the
428 * repository depending on the phase of the moon.
429 */
430 if (access_hook && run_access_hook(service, dir, path, hi))
431 return -1;
432
433 /*
434 * We'll ignore SIGTERM from now on, we have a
435 * good client.
436 */
437 signal(SIGTERM, SIG_IGN);
438
439 return service->fn(env);
440 }
441
442 static void copy_to_log(int fd)
443 {
444 struct strbuf line = STRBUF_INIT;
445 FILE *fp;
446
447 fp = fdopen(fd, "r");
448 if (fp == NULL) {
449 logerror("fdopen of error channel failed");
450 close(fd);
451 return;
452 }
453
454 while (strbuf_getline_lf(&line, fp) != EOF) {
455 logerror("%s", line.buf);
456 strbuf_setlen(&line, 0);
457 }
458
459 strbuf_release(&line);
460 fclose(fp);
461 }
462
463 static int run_service_command(struct child_process *cld)
464 {
465 strvec_push(&cld->args, ".");
466 cld->git_cmd = 1;
467 cld->err = -1;
468 if (start_command(cld))
469 return -1;
470
471 close(0);
472 close(1);
473
474 copy_to_log(cld->err);
475
476 return finish_command(cld);
477 }
478
479 static int upload_pack(const struct strvec *env)
480 {
481 struct child_process cld = CHILD_PROCESS_INIT;
482 strvec_pushl(&cld.args, "upload-pack", "--strict", NULL);
483 strvec_pushf(&cld.args, "--timeout=%u", timeout);
484
485 strvec_pushv(&cld.env_array, env->v);
486
487 return run_service_command(&cld);
488 }
489
490 static int upload_archive(const struct strvec *env)
491 {
492 struct child_process cld = CHILD_PROCESS_INIT;
493 strvec_push(&cld.args, "upload-archive");
494
495 strvec_pushv(&cld.env_array, env->v);
496
497 return run_service_command(&cld);
498 }
499
500 static int receive_pack(const struct strvec *env)
501 {
502 struct child_process cld = CHILD_PROCESS_INIT;
503 strvec_push(&cld.args, "receive-pack");
504
505 strvec_pushv(&cld.env_array, env->v);
506
507 return run_service_command(&cld);
508 }
509
510 static struct daemon_service daemon_service[] = {
511 { "upload-archive", "uploadarch", upload_archive, 0, 1 },
512 { "upload-pack", "uploadpack", upload_pack, 1, 1 },
513 { "receive-pack", "receivepack", receive_pack, 0, 1 },
514 };
515
516 static void enable_service(const char *name, int ena)
517 {
518 int i;
519 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
520 if (!strcmp(daemon_service[i].name, name)) {
521 daemon_service[i].enabled = ena;
522 return;
523 }
524 }
525 die("No such service %s", name);
526 }
527
528 static void make_service_overridable(const char *name, int ena)
529 {
530 int i;
531 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
532 if (!strcmp(daemon_service[i].name, name)) {
533 daemon_service[i].overridable = ena;
534 return;
535 }
536 }
537 die("No such service %s", name);
538 }
539
540 static void parse_host_and_port(char *hostport, char **host,
541 char **port)
542 {
543 if (*hostport == '[') {
544 char *end;
545
546 end = strchr(hostport, ']');
547 if (!end)
548 die("Invalid request ('[' without ']')");
549 *end = '\0';
550 *host = hostport + 1;
551 if (!end[1])
552 *port = NULL;
553 else if (end[1] == ':')
554 *port = end + 2;
555 else
556 die("Garbage after end of host part");
557 } else {
558 *host = hostport;
559 *port = strrchr(hostport, ':');
560 if (*port) {
561 **port = '\0';
562 ++*port;
563 }
564 }
565 }
566
567 /*
568 * Sanitize a string from the client so that it's OK to be inserted into a
569 * filesystem path. Specifically, we disallow slashes, runs of "..", and
570 * trailing and leading dots, which means that the client cannot escape
571 * our base path via ".." traversal.
572 */
573 static void sanitize_client(struct strbuf *out, const char *in)
574 {
575 for (; *in; in++) {
576 if (*in == '/')
577 continue;
578 if (*in == '.' && (!out->len || out->buf[out->len - 1] == '.'))
579 continue;
580 strbuf_addch(out, *in);
581 }
582
583 while (out->len && out->buf[out->len - 1] == '.')
584 strbuf_setlen(out, out->len - 1);
585 }
586
587 /*
588 * Like sanitize_client, but we also perform any canonicalization
589 * to make life easier on the admin.
590 */
591 static void canonicalize_client(struct strbuf *out, const char *in)
592 {
593 sanitize_client(out, in);
594 strbuf_tolower(out);
595 }
596
597 /*
598 * Read the host as supplied by the client connection.
599 *
600 * Returns a pointer to the character after the NUL byte terminating the host
601 * argument, or 'extra_args' if there is no host argument.
602 */
603 static char *parse_host_arg(struct hostinfo *hi, char *extra_args, int buflen)
604 {
605 char *val;
606 int vallen;
607 char *end = extra_args + buflen;
608
609 if (extra_args < end && *extra_args) {
610 hi->saw_extended_args = 1;
611 if (strncasecmp("host=", extra_args, 5) == 0) {
612 val = extra_args + 5;
613 vallen = strlen(val) + 1;
614 loginfo("Extended attribute \"host\": %s", val);
615 if (*val) {
616 /* Split <host>:<port> at colon. */
617 char *host;
618 char *port;
619 parse_host_and_port(val, &host, &port);
620 if (port)
621 sanitize_client(&hi->tcp_port, port);
622 canonicalize_client(&hi->hostname, host);
623 hi->hostname_lookup_done = 0;
624 }
625
626 /* On to the next one */
627 extra_args = val + vallen;
628 }
629 if (extra_args < end && *extra_args)
630 die("Invalid request");
631 }
632
633 return extra_args;
634 }
635
636 static void parse_extra_args(struct hostinfo *hi, struct strvec *env,
637 char *extra_args, int buflen)
638 {
639 const char *end = extra_args + buflen;
640 struct strbuf git_protocol = STRBUF_INIT;
641
642 /* First look for the host argument */
643 extra_args = parse_host_arg(hi, extra_args, buflen);
644
645 /* Look for additional arguments places after a second NUL byte */
646 for (; extra_args < end; extra_args += strlen(extra_args) + 1) {
647 const char *arg = extra_args;
648
649 /*
650 * Parse the extra arguments, adding most to 'git_protocol'
651 * which will be used to set the 'GIT_PROTOCOL' envvar in the
652 * service that will be run.
653 *
654 * If there ends up being a particular arg in the future that
655 * git-daemon needs to parse specifically (like the 'host' arg)
656 * then it can be parsed here and not added to 'git_protocol'.
657 */
658 if (*arg) {
659 if (git_protocol.len > 0)
660 strbuf_addch(&git_protocol, ':');
661 strbuf_addstr(&git_protocol, arg);
662 }
663 }
664
665 if (git_protocol.len > 0) {
666 loginfo("Extended attribute \"protocol\": %s", git_protocol.buf);
667 strvec_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=%s",
668 git_protocol.buf);
669 }
670 strbuf_release(&git_protocol);
671 }
672
673 /*
674 * Locate canonical hostname and its IP address.
675 */
676 static void lookup_hostname(struct hostinfo *hi)
677 {
678 if (!hi->hostname_lookup_done && hi->hostname.len) {
679 #ifndef NO_IPV6
680 struct addrinfo hints;
681 struct addrinfo *ai;
682 int gai;
683 static char addrbuf[HOST_NAME_MAX + 1];
684
685 memset(&hints, 0, sizeof(hints));
686 hints.ai_flags = AI_CANONNAME;
687
688 gai = getaddrinfo(hi->hostname.buf, NULL, &hints, &ai);
689 if (!gai) {
690 struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
691
692 inet_ntop(AF_INET, &sin_addr->sin_addr,
693 addrbuf, sizeof(addrbuf));
694 strbuf_addstr(&hi->ip_address, addrbuf);
695
696 if (ai->ai_canonname)
697 sanitize_client(&hi->canon_hostname,
698 ai->ai_canonname);
699 else
700 strbuf_addbuf(&hi->canon_hostname,
701 &hi->ip_address);
702
703 freeaddrinfo(ai);
704 }
705 #else
706 struct hostent *hent;
707 struct sockaddr_in sa;
708 char **ap;
709 static char addrbuf[HOST_NAME_MAX + 1];
710
711 hent = gethostbyname(hi->hostname.buf);
712 if (hent) {
713 ap = hent->h_addr_list;
714 memset(&sa, 0, sizeof sa);
715 sa.sin_family = hent->h_addrtype;
716 sa.sin_port = htons(0);
717 memcpy(&sa.sin_addr, *ap, hent->h_length);
718
719 inet_ntop(hent->h_addrtype, &sa.sin_addr,
720 addrbuf, sizeof(addrbuf));
721
722 sanitize_client(&hi->canon_hostname, hent->h_name);
723 strbuf_addstr(&hi->ip_address, addrbuf);
724 }
725 #endif
726 hi->hostname_lookup_done = 1;
727 }
728 }
729
730 static void hostinfo_init(struct hostinfo *hi)
731 {
732 memset(hi, 0, sizeof(*hi));
733 strbuf_init(&hi->hostname, 0);
734 strbuf_init(&hi->canon_hostname, 0);
735 strbuf_init(&hi->ip_address, 0);
736 strbuf_init(&hi->tcp_port, 0);
737 }
738
739 static void hostinfo_clear(struct hostinfo *hi)
740 {
741 strbuf_release(&hi->hostname);
742 strbuf_release(&hi->canon_hostname);
743 strbuf_release(&hi->ip_address);
744 strbuf_release(&hi->tcp_port);
745 }
746
747 static void set_keep_alive(int sockfd)
748 {
749 int ka = 1;
750
751 if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0) {
752 if (errno != ENOTSOCK)
753 logerror("unable to set SO_KEEPALIVE on socket: %s",
754 strerror(errno));
755 }
756 }
757
758 static int execute(void)
759 {
760 char *line = packet_buffer;
761 int pktlen, len, i;
762 char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
763 struct hostinfo hi;
764 struct strvec env = STRVEC_INIT;
765
766 hostinfo_init(&hi);
767
768 if (addr)
769 loginfo("Connection from %s:%s", addr, port);
770
771 set_keep_alive(0);
772 alarm(init_timeout ? init_timeout : timeout);
773 pktlen = packet_read(0, NULL, NULL, packet_buffer, sizeof(packet_buffer), 0);
774 alarm(0);
775
776 len = strlen(line);
777 if (len && line[len-1] == '\n')
778 line[len-1] = 0;
779
780 /* parse additional args hidden behind a NUL byte */
781 if (len != pktlen)
782 parse_extra_args(&hi, &env, line + len + 1, pktlen - len - 1);
783
784 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
785 struct daemon_service *s = &(daemon_service[i]);
786 const char *arg;
787
788 if (skip_prefix(line, "git-", &arg) &&
789 skip_prefix(arg, s->name, &arg) &&
790 *arg++ == ' ') {
791 /*
792 * Note: The directory here is probably context sensitive,
793 * and might depend on the actual service being performed.
794 */
795 int rc = run_service(arg, s, &hi, &env);
796 hostinfo_clear(&hi);
797 strvec_clear(&env);
798 return rc;
799 }
800 }
801
802 hostinfo_clear(&hi);
803 strvec_clear(&env);
804 logerror("Protocol error: '%s'", line);
805 return -1;
806 }
807
808 static int addrcmp(const struct sockaddr_storage *s1,
809 const struct sockaddr_storage *s2)
810 {
811 const struct sockaddr *sa1 = (const struct sockaddr*) s1;
812 const struct sockaddr *sa2 = (const struct sockaddr*) s2;
813
814 if (sa1->sa_family != sa2->sa_family)
815 return sa1->sa_family - sa2->sa_family;
816 if (sa1->sa_family == AF_INET)
817 return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
818 &((struct sockaddr_in *)s2)->sin_addr,
819 sizeof(struct in_addr));
820 #ifndef NO_IPV6
821 if (sa1->sa_family == AF_INET6)
822 return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
823 &((struct sockaddr_in6 *)s2)->sin6_addr,
824 sizeof(struct in6_addr));
825 #endif
826 return 0;
827 }
828
829 static int max_connections = 32;
830
831 static unsigned int live_children;
832
833 static struct child {
834 struct child *next;
835 struct child_process cld;
836 struct sockaddr_storage address;
837 } *firstborn;
838
839 static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
840 {
841 struct child *newborn, **cradle;
842
843 newborn = xcalloc(1, sizeof(*newborn));
844 live_children++;
845 memcpy(&newborn->cld, cld, sizeof(*cld));
846 memcpy(&newborn->address, addr, addrlen);
847 for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
848 if (!addrcmp(&(*cradle)->address, &newborn->address))
849 break;
850 newborn->next = *cradle;
851 *cradle = newborn;
852 }
853
854 /*
855 * This gets called if the number of connections grows
856 * past "max_connections".
857 *
858 * We kill the newest connection from a duplicate IP.
859 */
860 static void kill_some_child(void)
861 {
862 const struct child *blanket, *next;
863
864 if (!(blanket = firstborn))
865 return;
866
867 for (; (next = blanket->next); blanket = next)
868 if (!addrcmp(&blanket->address, &next->address)) {
869 kill(blanket->cld.pid, SIGTERM);
870 break;
871 }
872 }
873
874 static void check_dead_children(void)
875 {
876 int status;
877 pid_t pid;
878
879 struct child **cradle, *blanket;
880 for (cradle = &firstborn; (blanket = *cradle);)
881 if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
882 const char *dead = "";
883 if (status)
884 dead = " (with error)";
885 loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
886
887 /* remove the child */
888 *cradle = blanket->next;
889 live_children--;
890 child_process_clear(&blanket->cld);
891 free(blanket);
892 } else
893 cradle = &blanket->next;
894 }
895
896 static struct strvec cld_argv = STRVEC_INIT;
897 static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
898 {
899 struct child_process cld = CHILD_PROCESS_INIT;
900
901 if (max_connections && live_children >= max_connections) {
902 kill_some_child();
903 sleep(1); /* give it some time to die */
904 check_dead_children();
905 if (live_children >= max_connections) {
906 close(incoming);
907 logerror("Too many children, dropping connection");
908 return;
909 }
910 }
911
912 if (addr->sa_family == AF_INET) {
913 char buf[128] = "";
914 struct sockaddr_in *sin_addr = (void *) addr;
915 inet_ntop(addr->sa_family, &sin_addr->sin_addr, buf, sizeof(buf));
916 strvec_pushf(&cld.env_array, "REMOTE_ADDR=%s", buf);
917 strvec_pushf(&cld.env_array, "REMOTE_PORT=%d",
918 ntohs(sin_addr->sin_port));
919 #ifndef NO_IPV6
920 } else if (addr->sa_family == AF_INET6) {
921 char buf[128] = "";
922 struct sockaddr_in6 *sin6_addr = (void *) addr;
923 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(buf));
924 strvec_pushf(&cld.env_array, "REMOTE_ADDR=[%s]", buf);
925 strvec_pushf(&cld.env_array, "REMOTE_PORT=%d",
926 ntohs(sin6_addr->sin6_port));
927 #endif
928 }
929
930 cld.argv = cld_argv.v;
931 cld.in = incoming;
932 cld.out = dup(incoming);
933
934 if (start_command(&cld))
935 logerror("unable to fork");
936 else
937 add_child(&cld, addr, addrlen);
938 }
939
940 static void child_handler(int signo)
941 {
942 /*
943 * Otherwise empty handler because systemcalls will get interrupted
944 * upon signal receipt
945 * SysV needs the handler to be rearmed
946 */
947 signal(SIGCHLD, child_handler);
948 }
949
950 static int set_reuse_addr(int sockfd)
951 {
952 int on = 1;
953
954 if (!reuseaddr)
955 return 0;
956 return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
957 &on, sizeof(on));
958 }
959
960 struct socketlist {
961 int *list;
962 size_t nr;
963 size_t alloc;
964 };
965
966 static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
967 {
968 #ifdef NO_IPV6
969 static char ip[INET_ADDRSTRLEN];
970 #else
971 static char ip[INET6_ADDRSTRLEN];
972 #endif
973
974 switch (family) {
975 #ifndef NO_IPV6
976 case AF_INET6:
977 inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
978 break;
979 #endif
980 case AF_INET:
981 inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
982 break;
983 default:
984 xsnprintf(ip, sizeof(ip), "<unknown>");
985 }
986 return ip;
987 }
988
989 #ifndef NO_IPV6
990
991 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
992 {
993 int socknum = 0;
994 char pbuf[NI_MAXSERV];
995 struct addrinfo hints, *ai0, *ai;
996 int gai;
997 long flags;
998
999 xsnprintf(pbuf, sizeof(pbuf), "%d", listen_port);
1000 memset(&hints, 0, sizeof(hints));
1001 hints.ai_family = AF_UNSPEC;
1002 hints.ai_socktype = SOCK_STREAM;
1003 hints.ai_protocol = IPPROTO_TCP;
1004 hints.ai_flags = AI_PASSIVE;
1005
1006 gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
1007 if (gai) {
1008 logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
1009 return 0;
1010 }
1011
1012 for (ai = ai0; ai; ai = ai->ai_next) {
1013 int sockfd;
1014
1015 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1016 if (sockfd < 0)
1017 continue;
1018 if (sockfd >= FD_SETSIZE) {
1019 logerror("Socket descriptor too large");
1020 close(sockfd);
1021 continue;
1022 }
1023
1024 #ifdef IPV6_V6ONLY
1025 if (ai->ai_family == AF_INET6) {
1026 int on = 1;
1027 setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
1028 &on, sizeof(on));
1029 /* Note: error is not fatal */
1030 }
1031 #endif
1032
1033 if (set_reuse_addr(sockfd)) {
1034 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1035 close(sockfd);
1036 continue;
1037 }
1038
1039 set_keep_alive(sockfd);
1040
1041 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
1042 logerror("Could not bind to %s: %s",
1043 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1044 strerror(errno));
1045 close(sockfd);
1046 continue; /* not fatal */
1047 }
1048 if (listen(sockfd, 5) < 0) {
1049 logerror("Could not listen to %s: %s",
1050 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1051 strerror(errno));
1052 close(sockfd);
1053 continue; /* not fatal */
1054 }
1055
1056 flags = fcntl(sockfd, F_GETFD, 0);
1057 if (flags >= 0)
1058 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1059
1060 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1061 socklist->list[socklist->nr++] = sockfd;
1062 socknum++;
1063 }
1064
1065 freeaddrinfo(ai0);
1066
1067 return socknum;
1068 }
1069
1070 #else /* NO_IPV6 */
1071
1072 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
1073 {
1074 struct sockaddr_in sin;
1075 int sockfd;
1076 long flags;
1077
1078 memset(&sin, 0, sizeof sin);
1079 sin.sin_family = AF_INET;
1080 sin.sin_port = htons(listen_port);
1081
1082 if (listen_addr) {
1083 /* Well, host better be an IP address here. */
1084 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
1085 return 0;
1086 } else {
1087 sin.sin_addr.s_addr = htonl(INADDR_ANY);
1088 }
1089
1090 sockfd = socket(AF_INET, SOCK_STREAM, 0);
1091 if (sockfd < 0)
1092 return 0;
1093
1094 if (set_reuse_addr(sockfd)) {
1095 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1096 close(sockfd);
1097 return 0;
1098 }
1099
1100 set_keep_alive(sockfd);
1101
1102 if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
1103 logerror("Could not bind to %s: %s",
1104 ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1105 strerror(errno));
1106 close(sockfd);
1107 return 0;
1108 }
1109
1110 if (listen(sockfd, 5) < 0) {
1111 logerror("Could not listen to %s: %s",
1112 ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1113 strerror(errno));
1114 close(sockfd);
1115 return 0;
1116 }
1117
1118 flags = fcntl(sockfd, F_GETFD, 0);
1119 if (flags >= 0)
1120 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1121
1122 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1123 socklist->list[socklist->nr++] = sockfd;
1124 return 1;
1125 }
1126
1127 #endif
1128
1129 static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
1130 {
1131 if (!listen_addr->nr)
1132 setup_named_sock(NULL, listen_port, socklist);
1133 else {
1134 int i, socknum;
1135 for (i = 0; i < listen_addr->nr; i++) {
1136 socknum = setup_named_sock(listen_addr->items[i].string,
1137 listen_port, socklist);
1138
1139 if (socknum == 0)
1140 logerror("unable to allocate any listen sockets for host %s on port %u",
1141 listen_addr->items[i].string, listen_port);
1142 }
1143 }
1144 }
1145
1146 static int service_loop(struct socketlist *socklist)
1147 {
1148 struct pollfd *pfd;
1149 int i;
1150
1151 pfd = xcalloc(socklist->nr, sizeof(struct pollfd));
1152
1153 for (i = 0; i < socklist->nr; i++) {
1154 pfd[i].fd = socklist->list[i];
1155 pfd[i].events = POLLIN;
1156 }
1157
1158 signal(SIGCHLD, child_handler);
1159
1160 for (;;) {
1161 int i;
1162
1163 check_dead_children();
1164
1165 if (poll(pfd, socklist->nr, -1) < 0) {
1166 if (errno != EINTR) {
1167 logerror("Poll failed, resuming: %s",
1168 strerror(errno));
1169 sleep(1);
1170 }
1171 continue;
1172 }
1173
1174 for (i = 0; i < socklist->nr; i++) {
1175 if (pfd[i].revents & POLLIN) {
1176 union {
1177 struct sockaddr sa;
1178 struct sockaddr_in sai;
1179 #ifndef NO_IPV6
1180 struct sockaddr_in6 sai6;
1181 #endif
1182 } ss;
1183 socklen_t sslen = sizeof(ss);
1184 int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1185 if (incoming < 0) {
1186 switch (errno) {
1187 case EAGAIN:
1188 case EINTR:
1189 case ECONNABORTED:
1190 continue;
1191 default:
1192 die_errno("accept returned");
1193 }
1194 }
1195 handle(incoming, &ss.sa, sslen);
1196 }
1197 }
1198 }
1199 }
1200
1201 #ifdef NO_POSIX_GOODIES
1202
1203 struct credentials;
1204
1205 static void drop_privileges(struct credentials *cred)
1206 {
1207 /* nothing */
1208 }
1209
1210 static struct credentials *prepare_credentials(const char *user_name,
1211 const char *group_name)
1212 {
1213 die("--user not supported on this platform");
1214 }
1215
1216 #else
1217
1218 struct credentials {
1219 struct passwd *pass;
1220 gid_t gid;
1221 };
1222
1223 static void drop_privileges(struct credentials *cred)
1224 {
1225 if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1226 setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1227 die("cannot drop privileges");
1228 }
1229
1230 static struct credentials *prepare_credentials(const char *user_name,
1231 const char *group_name)
1232 {
1233 static struct credentials c;
1234
1235 c.pass = getpwnam(user_name);
1236 if (!c.pass)
1237 die("user not found - %s", user_name);
1238
1239 if (!group_name)
1240 c.gid = c.pass->pw_gid;
1241 else {
1242 struct group *group = getgrnam(group_name);
1243 if (!group)
1244 die("group not found - %s", group_name);
1245
1246 c.gid = group->gr_gid;
1247 }
1248
1249 return &c;
1250 }
1251 #endif
1252
1253 static int serve(struct string_list *listen_addr, int listen_port,
1254 struct credentials *cred)
1255 {
1256 struct socketlist socklist = { NULL, 0, 0 };
1257
1258 socksetup(listen_addr, listen_port, &socklist);
1259 if (socklist.nr == 0)
1260 die("unable to allocate any listen sockets on port %u",
1261 listen_port);
1262
1263 drop_privileges(cred);
1264
1265 loginfo("Ready to rumble");
1266
1267 return service_loop(&socklist);
1268 }
1269
1270 int cmd_main(int argc, const char **argv)
1271 {
1272 int listen_port = 0;
1273 struct string_list listen_addr = STRING_LIST_INIT_NODUP;
1274 int serve_mode = 0, inetd_mode = 0;
1275 const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1276 int detach = 0;
1277 struct credentials *cred = NULL;
1278 int i;
1279
1280 for (i = 1; i < argc; i++) {
1281 const char *arg = argv[i];
1282 const char *v;
1283
1284 if (skip_prefix(arg, "--listen=", &v)) {
1285 string_list_append(&listen_addr, xstrdup_tolower(v));
1286 continue;
1287 }
1288 if (skip_prefix(arg, "--port=", &v)) {
1289 char *end;
1290 unsigned long n;
1291 n = strtoul(v, &end, 0);
1292 if (*v && !*end) {
1293 listen_port = n;
1294 continue;
1295 }
1296 }
1297 if (!strcmp(arg, "--serve")) {
1298 serve_mode = 1;
1299 continue;
1300 }
1301 if (!strcmp(arg, "--inetd")) {
1302 inetd_mode = 1;
1303 continue;
1304 }
1305 if (!strcmp(arg, "--verbose")) {
1306 verbose = 1;
1307 continue;
1308 }
1309 if (!strcmp(arg, "--syslog")) {
1310 log_destination = LOG_DESTINATION_SYSLOG;
1311 continue;
1312 }
1313 if (skip_prefix(arg, "--log-destination=", &v)) {
1314 if (!strcmp(v, "syslog")) {
1315 log_destination = LOG_DESTINATION_SYSLOG;
1316 continue;
1317 } else if (!strcmp(v, "stderr")) {
1318 log_destination = LOG_DESTINATION_STDERR;
1319 continue;
1320 } else if (!strcmp(v, "none")) {
1321 log_destination = LOG_DESTINATION_NONE;
1322 continue;
1323 } else
1324 die("unknown log destination '%s'", v);
1325 }
1326 if (!strcmp(arg, "--export-all")) {
1327 export_all_trees = 1;
1328 continue;
1329 }
1330 if (skip_prefix(arg, "--access-hook=", &v)) {
1331 access_hook = v;
1332 continue;
1333 }
1334 if (skip_prefix(arg, "--timeout=", &v)) {
1335 timeout = atoi(v);
1336 continue;
1337 }
1338 if (skip_prefix(arg, "--init-timeout=", &v)) {
1339 init_timeout = atoi(v);
1340 continue;
1341 }
1342 if (skip_prefix(arg, "--max-connections=", &v)) {
1343 max_connections = atoi(v);
1344 if (max_connections < 0)
1345 max_connections = 0; /* unlimited */
1346 continue;
1347 }
1348 if (!strcmp(arg, "--strict-paths")) {
1349 strict_paths = 1;
1350 continue;
1351 }
1352 if (skip_prefix(arg, "--base-path=", &v)) {
1353 base_path = v;
1354 continue;
1355 }
1356 if (!strcmp(arg, "--base-path-relaxed")) {
1357 base_path_relaxed = 1;
1358 continue;
1359 }
1360 if (skip_prefix(arg, "--interpolated-path=", &v)) {
1361 interpolated_path = v;
1362 continue;
1363 }
1364 if (!strcmp(arg, "--reuseaddr")) {
1365 reuseaddr = 1;
1366 continue;
1367 }
1368 if (!strcmp(arg, "--user-path")) {
1369 user_path = "";
1370 continue;
1371 }
1372 if (skip_prefix(arg, "--user-path=", &v)) {
1373 user_path = v;
1374 continue;
1375 }
1376 if (skip_prefix(arg, "--pid-file=", &v)) {
1377 pid_file = v;
1378 continue;
1379 }
1380 if (!strcmp(arg, "--detach")) {
1381 detach = 1;
1382 continue;
1383 }
1384 if (skip_prefix(arg, "--user=", &v)) {
1385 user_name = v;
1386 continue;
1387 }
1388 if (skip_prefix(arg, "--group=", &v)) {
1389 group_name = v;
1390 continue;
1391 }
1392 if (skip_prefix(arg, "--enable=", &v)) {
1393 enable_service(v, 1);
1394 continue;
1395 }
1396 if (skip_prefix(arg, "--disable=", &v)) {
1397 enable_service(v, 0);
1398 continue;
1399 }
1400 if (skip_prefix(arg, "--allow-override=", &v)) {
1401 make_service_overridable(v, 1);
1402 continue;
1403 }
1404 if (skip_prefix(arg, "--forbid-override=", &v)) {
1405 make_service_overridable(v, 0);
1406 continue;
1407 }
1408 if (!strcmp(arg, "--informative-errors")) {
1409 informative_errors = 1;
1410 continue;
1411 }
1412 if (!strcmp(arg, "--no-informative-errors")) {
1413 informative_errors = 0;
1414 continue;
1415 }
1416 if (!strcmp(arg, "--")) {
1417 ok_paths = &argv[i+1];
1418 break;
1419 } else if (arg[0] != '-') {
1420 ok_paths = &argv[i];
1421 break;
1422 }
1423
1424 usage(daemon_usage);
1425 }
1426
1427 if (log_destination == LOG_DESTINATION_UNSET) {
1428 if (inetd_mode || detach)
1429 log_destination = LOG_DESTINATION_SYSLOG;
1430 else
1431 log_destination = LOG_DESTINATION_STDERR;
1432 }
1433
1434 if (log_destination == LOG_DESTINATION_SYSLOG) {
1435 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1436 set_die_routine(daemon_die);
1437 } else
1438 /* avoid splitting a message in the middle */
1439 setvbuf(stderr, NULL, _IOFBF, 4096);
1440
1441 if (inetd_mode && (detach || group_name || user_name))
1442 die("--detach, --user and --group are incompatible with --inetd");
1443
1444 if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1445 die("--listen= and --port= are incompatible with --inetd");
1446 else if (listen_port == 0)
1447 listen_port = DEFAULT_GIT_PORT;
1448
1449 if (group_name && !user_name)
1450 die("--group supplied without --user");
1451
1452 if (user_name)
1453 cred = prepare_credentials(user_name, group_name);
1454
1455 if (strict_paths && (!ok_paths || !*ok_paths))
1456 die("option --strict-paths requires a whitelist");
1457
1458 if (base_path && !is_directory(base_path))
1459 die("base-path '%s' does not exist or is not a directory",
1460 base_path);
1461
1462 if (log_destination != LOG_DESTINATION_STDERR) {
1463 if (!freopen("/dev/null", "w", stderr))
1464 die_errno("failed to redirect stderr to /dev/null");
1465 }
1466
1467 if (inetd_mode || serve_mode)
1468 return execute();
1469
1470 if (detach) {
1471 if (daemonize())
1472 die("--detach not supported on this platform");
1473 }
1474
1475 if (pid_file)
1476 write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
1477
1478 /* prepare argv for serving-processes */
1479 strvec_push(&cld_argv, argv[0]); /* git-daemon */
1480 strvec_push(&cld_argv, "--serve");
1481 for (i = 1; i < argc; ++i)
1482 strvec_push(&cld_argv, argv[i]);
1483
1484 return serve(&listen_addr, listen_port, cred);
1485 }
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