freshlybakedca.ke
Git fork
1#define USE_THE_REPOSITORY_VARIABLE
2
3#include "git-compat-util.h"
4#include "abspath.h"
5#include "config.h"
6#include "environment.h"
7#include "gettext.h"
8#include "path.h"
9#include "pkt-line.h"
10#include "protocol.h"
11#include "run-command.h"
12#include "setup.h"
13#include "strbuf.h"
14#include "string-list.h"
15
16#ifdef NO_INITGROUPS
17#define initgroups(x, y) (0) /* nothing */
18#endif
19
20static enum log_destination {
21 LOG_DESTINATION_UNSET = -1,
22 LOG_DESTINATION_NONE = 0,
23 LOG_DESTINATION_STDERR = 1,
24 LOG_DESTINATION_SYSLOG = 2,
25} log_destination = LOG_DESTINATION_UNSET;
26static int verbose;
27static int reuseaddr;
28static int informative_errors;
29
30static const char daemon_usage[] =
31"git daemon [--verbose] [--syslog] [--export-all]\n"
32" [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n"
33" [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
34" [--user-path | --user-path=<path>]\n"
35" [--interpolated-path=<path>]\n"
36" [--reuseaddr] [--pid-file=<file>]\n"
37" [--(enable|disable|allow-override|forbid-override)=<service>]\n"
38" [--access-hook=<path>]\n"
39" [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
40" [--detach] [--user=<user> [--group=<group>]]\n"
41" [--log-destination=(stderr|syslog|none)]\n"
42" [<directory>...]";
43
44/* List of acceptable pathname prefixes */
45static const char **ok_paths;
46static int strict_paths;
47
48/* If this is set, git-daemon-export-ok is not required */
49static int export_all_trees;
50
51/* Take all paths relative to this one if non-NULL */
52static const char *base_path;
53static const char *interpolated_path;
54static int base_path_relaxed;
55
56/* If defined, ~user notation is allowed and the string is inserted
57 * after ~user/. E.g. a request to git://host/~alice/frotz would
58 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
59 */
60static const char *user_path;
61
62/* Timeout, and initial timeout */
63static unsigned int timeout;
64static unsigned int init_timeout;
65
66struct hostinfo {
67 struct strbuf hostname;
68 struct strbuf canon_hostname;
69 struct strbuf ip_address;
70 struct strbuf tcp_port;
71 unsigned int hostname_lookup_done:1;
72 unsigned int saw_extended_args:1;
73};
74#define HOSTINFO_INIT { \
75 .hostname = STRBUF_INIT, \
76 .canon_hostname = STRBUF_INIT, \
77 .ip_address = STRBUF_INIT, \
78 .tcp_port = STRBUF_INIT, \
79}
80
81static void lookup_hostname(struct hostinfo *hi);
82
83static const char *get_canon_hostname(struct hostinfo *hi)
84{
85 lookup_hostname(hi);
86 return hi->canon_hostname.buf;
87}
88
89static const char *get_ip_address(struct hostinfo *hi)
90{
91 lookup_hostname(hi);
92 return hi->ip_address.buf;
93}
94
95static void logreport(int priority, const char *err, va_list params)
96{
97 switch (log_destination) {
98 case LOG_DESTINATION_SYSLOG: {
99 char buf[1024];
100 vsnprintf(buf, sizeof(buf), err, params);
101 syslog(priority, "%s", buf);
102 break;
103 }
104 case LOG_DESTINATION_STDERR:
105 /*
106 * Since stderr is set to buffered mode, the
107 * logging of different processes will not overlap
108 * unless they overflow the (rather big) buffers.
109 */
110 fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
111 vfprintf(stderr, err, params);
112 fputc('\n', stderr);
113 fflush(stderr);
114 break;
115 case LOG_DESTINATION_NONE:
116 break;
117 case LOG_DESTINATION_UNSET:
118 BUG("log destination not initialized correctly");
119 }
120}
121
122__attribute__((format (printf, 1, 2)))
123static void logerror(const char *err, ...)
124{
125 va_list params;
126 va_start(params, err);
127 logreport(LOG_ERR, err, params);
128 va_end(params);
129}
130
131__attribute__((format (printf, 1, 2)))
132static void loginfo(const char *err, ...)
133{
134 va_list params;
135 if (!verbose)
136 return;
137 va_start(params, err);
138 logreport(LOG_INFO, err, params);
139 va_end(params);
140}
141
142static void NORETURN daemon_die(const char *err, va_list params)
143{
144 logreport(LOG_ERR, err, params);
145 exit(1);
146}
147
148static const char *path_ok(const char *directory, struct hostinfo *hi)
149{
150 static char rpath[PATH_MAX];
151 static char interp_path[PATH_MAX];
152 size_t rlen;
153 const char *path;
154 const char *dir;
155 unsigned enter_repo_flags;
156
157 dir = directory;
158
159 if (daemon_avoid_alias(dir)) {
160 logerror("'%s': aliased", dir);
161 return NULL;
162 }
163
164 if (*dir == '~') {
165 if (!user_path) {
166 logerror("'%s': User-path not allowed", dir);
167 return NULL;
168 }
169 if (*user_path) {
170 /* Got either "~alice" or "~alice/foo";
171 * rewrite them to "~alice/%s" or
172 * "~alice/%s/foo".
173 */
174 int namlen, restlen = strlen(dir);
175 const char *slash = strchr(dir, '/');
176 if (!slash)
177 slash = dir + restlen;
178 namlen = slash - dir;
179 restlen -= namlen;
180 loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
181 rlen = snprintf(rpath, sizeof(rpath), "%.*s/%s%.*s",
182 namlen, dir, user_path, restlen, slash);
183 if (rlen >= sizeof(rpath)) {
184 logerror("user-path too large: %s", rpath);
185 return NULL;
186 }
187 dir = rpath;
188 }
189 }
190 else if (interpolated_path && hi->saw_extended_args) {
191 struct strbuf expanded_path = STRBUF_INIT;
192 const char *format = interpolated_path;
193
194 if (*dir != '/') {
195 /* Allow only absolute */
196 logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
197 return NULL;
198 }
199
200 while (strbuf_expand_step(&expanded_path, &format)) {
201 if (skip_prefix(format, "%", &format))
202 strbuf_addch(&expanded_path, '%');
203 else if (skip_prefix(format, "H", &format))
204 strbuf_addbuf(&expanded_path, &hi->hostname);
205 else if (skip_prefix(format, "CH", &format))
206 strbuf_addstr(&expanded_path,
207 get_canon_hostname(hi));
208 else if (skip_prefix(format, "IP", &format))
209 strbuf_addstr(&expanded_path,
210 get_ip_address(hi));
211 else if (skip_prefix(format, "P", &format))
212 strbuf_addbuf(&expanded_path, &hi->tcp_port);
213 else if (skip_prefix(format, "D", &format))
214 strbuf_addstr(&expanded_path, directory);
215 else
216 strbuf_addch(&expanded_path, '%');
217 }
218
219 rlen = strlcpy(interp_path, expanded_path.buf,
220 sizeof(interp_path));
221 strbuf_release(&expanded_path);
222 if (rlen >= sizeof(interp_path)) {
223 logerror("interpolated path too large: %s",
224 interp_path);
225 return NULL;
226 }
227
228 loginfo("Interpolated dir '%s'", interp_path);
229
230 dir = interp_path;
231 }
232 else if (base_path) {
233 if (*dir != '/') {
234 /* Allow only absolute */
235 logerror("'%s': Non-absolute path denied (base-path active)", dir);
236 return NULL;
237 }
238 rlen = snprintf(rpath, sizeof(rpath), "%s%s", base_path, dir);
239 if (rlen >= sizeof(rpath)) {
240 logerror("base-path too large: %s", rpath);
241 return NULL;
242 }
243 dir = rpath;
244 }
245
246 enter_repo_flags = strict_paths ? ENTER_REPO_STRICT : 0;
247 path = enter_repo(dir, enter_repo_flags);
248 if (!path && base_path && base_path_relaxed) {
249 /*
250 * if we fail and base_path_relaxed is enabled, try without
251 * prefixing the base path
252 */
253 dir = directory;
254 path = enter_repo(dir, enter_repo_flags);
255 }
256
257 if (!path) {
258 logerror("'%s' does not appear to be a git repository", dir);
259 return NULL;
260 }
261
262 if ( ok_paths && *ok_paths ) {
263 const char **pp;
264 int pathlen = strlen(path);
265
266 /* The validation is done on the paths after enter_repo
267 * appends optional {.git,.git/.git} and friends, but
268 * it does not use getcwd(). So if your /pub is
269 * a symlink to /mnt/pub, you can include /pub and
270 * do not have to say /mnt/pub.
271 * Do not say /pub/.
272 */
273 for ( pp = ok_paths ; *pp ; pp++ ) {
274 int len = strlen(*pp);
275 if (len <= pathlen &&
276 !memcmp(*pp, path, len) &&
277 (path[len] == '\0' ||
278 (!strict_paths && path[len] == '/')))
279 return path;
280 }
281 }
282 else {
283 /* be backwards compatible */
284 if (!strict_paths)
285 return path;
286 }
287
288 logerror("'%s': not in directory list", path);
289 return NULL; /* Fallthrough. Deny by default */
290}
291
292typedef int (*daemon_service_fn)(const struct strvec *env);
293struct daemon_service {
294 const char *name;
295 const char *config_name;
296 daemon_service_fn fn;
297 int enabled;
298 int overridable;
299};
300
301static int daemon_error(const char *dir, const char *msg)
302{
303 if (!informative_errors)
304 msg = "access denied or repository not exported";
305 packet_write_fmt(1, "ERR %s: %s", msg, dir);
306 return -1;
307}
308
309static const char *access_hook;
310
311static int run_access_hook(struct daemon_service *service, const char *dir,
312 const char *path, struct hostinfo *hi)
313{
314 struct child_process child = CHILD_PROCESS_INIT;
315 struct strbuf buf = STRBUF_INIT;
316 char *eol;
317 int seen_errors = 0;
318
319 strvec_push(&child.args, access_hook);
320 strvec_push(&child.args, service->name);
321 strvec_push(&child.args, path);
322 strvec_push(&child.args, hi->hostname.buf);
323 strvec_push(&child.args, get_canon_hostname(hi));
324 strvec_push(&child.args, get_ip_address(hi));
325 strvec_push(&child.args, hi->tcp_port.buf);
326
327 child.use_shell = 1;
328 child.no_stdin = 1;
329 child.no_stderr = 1;
330 child.out = -1;
331 if (start_command(&child)) {
332 logerror("daemon access hook '%s' failed to start",
333 access_hook);
334 goto error_return;
335 }
336 if (strbuf_read(&buf, child.out, 0) < 0) {
337 logerror("failed to read from pipe to daemon access hook '%s'",
338 access_hook);
339 strbuf_reset(&buf);
340 seen_errors = 1;
341 }
342 if (close(child.out) < 0) {
343 logerror("failed to close pipe to daemon access hook '%s'",
344 access_hook);
345 seen_errors = 1;
346 }
347 if (finish_command(&child))
348 seen_errors = 1;
349
350 if (!seen_errors) {
351 strbuf_release(&buf);
352 return 0;
353 }
354
355error_return:
356 strbuf_ltrim(&buf);
357 if (!buf.len)
358 strbuf_addstr(&buf, "service rejected");
359 eol = strchr(buf.buf, '\n');
360 if (eol)
361 *eol = '\0';
362 errno = EACCES;
363 daemon_error(dir, buf.buf);
364 strbuf_release(&buf);
365 return -1;
366}
367
368static int run_service(const char *dir, struct daemon_service *service,
369 struct hostinfo *hi, const struct strvec *env)
370{
371 const char *path;
372 int enabled = service->enabled;
373 struct strbuf var = STRBUF_INIT;
374
375 loginfo("Request %s for '%s'", service->name, dir);
376
377 if (!enabled && !service->overridable) {
378 logerror("'%s': service not enabled.", service->name);
379 errno = EACCES;
380 return daemon_error(dir, "service not enabled");
381 }
382
383 if (!(path = path_ok(dir, hi)))
384 return daemon_error(dir, "no such repository");
385
386 /*
387 * Security on the cheap.
388 *
389 * We want a readable HEAD, usable "objects" directory, and
390 * a "git-daemon-export-ok" flag that says that the other side
391 * is ok with us doing this.
392 *
393 * path_ok() uses enter_repo() and checks for included directories.
394 * We only need to make sure the repository is exported.
395 */
396
397 if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
398 logerror("'%s': repository not exported.", path);
399 errno = EACCES;
400 return daemon_error(dir, "repository not exported");
401 }
402
403 if (service->overridable) {
404 strbuf_addf(&var, "daemon.%s", service->config_name);
405 repo_config_get_bool(the_repository, var.buf, &enabled);
406 strbuf_release(&var);
407 }
408 if (!enabled) {
409 logerror("'%s': service not enabled for '%s'",
410 service->name, path);
411 errno = EACCES;
412 return daemon_error(dir, "service not enabled");
413 }
414
415 /*
416 * Optionally, a hook can choose to deny access to the
417 * repository depending on the phase of the moon.
418 */
419 if (access_hook && run_access_hook(service, dir, path, hi))
420 return -1;
421
422 /*
423 * We'll ignore SIGTERM from now on, we have a
424 * good client.
425 */
426 signal(SIGTERM, SIG_IGN);
427
428 return service->fn(env);
429}
430
431static void copy_to_log(int fd)
432{
433 struct strbuf line = STRBUF_INIT;
434 FILE *fp;
435
436 fp = fdopen(fd, "r");
437 if (!fp) {
438 logerror("fdopen of error channel failed");
439 close(fd);
440 return;
441 }
442
443 while (strbuf_getline_lf(&line, fp) != EOF) {
444 logerror("%s", line.buf);
445 strbuf_setlen(&line, 0);
446 }
447
448 strbuf_release(&line);
449 fclose(fp);
450}
451
452static int run_service_command(struct child_process *cld)
453{
454 strvec_push(&cld->args, ".");
455 cld->git_cmd = 1;
456 cld->err = -1;
457 if (start_command(cld))
458 return -1;
459
460 close(0);
461 close(1);
462
463 copy_to_log(cld->err);
464
465 return finish_command(cld);
466}
467
468static int upload_pack(const struct strvec *env)
469{
470 struct child_process cld = CHILD_PROCESS_INIT;
471 strvec_pushl(&cld.args, "upload-pack", "--strict", NULL);
472 strvec_pushf(&cld.args, "--timeout=%u", timeout);
473
474 strvec_pushv(&cld.env, env->v);
475
476 return run_service_command(&cld);
477}
478
479static int upload_archive(const struct strvec *env)
480{
481 struct child_process cld = CHILD_PROCESS_INIT;
482 strvec_push(&cld.args, "upload-archive");
483
484 strvec_pushv(&cld.env, env->v);
485
486 return run_service_command(&cld);
487}
488
489static int receive_pack(const struct strvec *env)
490{
491 struct child_process cld = CHILD_PROCESS_INIT;
492 strvec_push(&cld.args, "receive-pack");
493
494 strvec_pushv(&cld.env, env->v);
495
496 return run_service_command(&cld);
497}
498
499static struct daemon_service daemon_service[] = {
500 { "upload-archive", "uploadarch", upload_archive, 0, 1 },
501 { "upload-pack", "uploadpack", upload_pack, 1, 1 },
502 { "receive-pack", "receivepack", receive_pack, 0, 1 },
503};
504
505static void enable_service(const char *name, int ena)
506{
507 for (size_t i = 0; i < ARRAY_SIZE(daemon_service); i++) {
508 if (!strcmp(daemon_service[i].name, name)) {
509 daemon_service[i].enabled = ena;
510 return;
511 }
512 }
513 die("No such service %s", name);
514}
515
516static void make_service_overridable(const char *name, int ena)
517{
518 for (size_t i = 0; i < ARRAY_SIZE(daemon_service); i++) {
519 if (!strcmp(daemon_service[i].name, name)) {
520 daemon_service[i].overridable = ena;
521 return;
522 }
523 }
524 die("No such service %s", name);
525}
526
527static void parse_host_and_port(char *hostport, char **host,
528 char **port)
529{
530 if (*hostport == '[') {
531 char *end;
532
533 end = strchr(hostport, ']');
534 if (!end)
535 die("Invalid request ('[' without ']')");
536 *end = '\0';
537 *host = hostport + 1;
538 if (!end[1])
539 *port = NULL;
540 else if (end[1] == ':')
541 *port = end + 2;
542 else
543 die("Garbage after end of host part");
544 } else {
545 *host = hostport;
546 *port = strrchr(hostport, ':');
547 if (*port) {
548 **port = '\0';
549 ++*port;
550 }
551 }
552}
553
554/*
555 * Sanitize a string from the client so that it's OK to be inserted into a
556 * filesystem path. Specifically, we disallow directory separators, runs
557 * of "..", and trailing and leading dots, which means that the client
558 * cannot escape our base path via ".." traversal.
559 */
560static void sanitize_client(struct strbuf *out, const char *in)
561{
562 for (; *in; in++) {
563 if (is_dir_sep(*in))
564 continue;
565 if (*in == '.' && (!out->len || out->buf[out->len - 1] == '.'))
566 continue;
567 strbuf_addch(out, *in);
568 }
569
570 while (out->len && out->buf[out->len - 1] == '.')
571 strbuf_setlen(out, out->len - 1);
572}
573
574/*
575 * Like sanitize_client, but we also perform any canonicalization
576 * to make life easier on the admin.
577 */
578static void canonicalize_client(struct strbuf *out, const char *in)
579{
580 sanitize_client(out, in);
581 strbuf_tolower(out);
582}
583
584/*
585 * Read the host as supplied by the client connection.
586 *
587 * Returns a pointer to the character after the NUL byte terminating the host
588 * argument, or 'extra_args' if there is no host argument.
589 */
590static char *parse_host_arg(struct hostinfo *hi, char *extra_args, int buflen)
591{
592 char *val;
593 int vallen;
594 char *end = extra_args + buflen;
595
596 if (extra_args < end && *extra_args) {
597 hi->saw_extended_args = 1;
598 if (strncasecmp("host=", extra_args, 5) == 0) {
599 val = extra_args + 5;
600 vallen = strlen(val) + 1;
601 loginfo("Extended attribute \"host\": %s", val);
602 if (*val) {
603 /* Split <host>:<port> at colon. */
604 char *host;
605 char *port;
606 parse_host_and_port(val, &host, &port);
607 if (port)
608 sanitize_client(&hi->tcp_port, port);
609 canonicalize_client(&hi->hostname, host);
610 hi->hostname_lookup_done = 0;
611 }
612
613 /* On to the next one */
614 extra_args = val + vallen;
615 }
616 if (extra_args < end && *extra_args)
617 die("Invalid request");
618 }
619
620 return extra_args;
621}
622
623static void parse_extra_args(struct hostinfo *hi, struct strvec *env,
624 char *extra_args, int buflen)
625{
626 const char *end = extra_args + buflen;
627 struct strbuf git_protocol = STRBUF_INIT;
628
629 /* First look for the host argument */
630 extra_args = parse_host_arg(hi, extra_args, buflen);
631
632 /* Look for additional arguments places after a second NUL byte */
633 for (; extra_args < end; extra_args += strlen(extra_args) + 1) {
634 const char *arg = extra_args;
635
636 /*
637 * Parse the extra arguments, adding most to 'git_protocol'
638 * which will be used to set the 'GIT_PROTOCOL' envvar in the
639 * service that will be run.
640 *
641 * If there ends up being a particular arg in the future that
642 * git-daemon needs to parse specifically (like the 'host' arg)
643 * then it can be parsed here and not added to 'git_protocol'.
644 */
645 if (*arg) {
646 if (git_protocol.len > 0)
647 strbuf_addch(&git_protocol, ':');
648 strbuf_addstr(&git_protocol, arg);
649 }
650 }
651
652 if (git_protocol.len > 0) {
653 loginfo("Extended attribute \"protocol\": %s", git_protocol.buf);
654 strvec_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=%s",
655 git_protocol.buf);
656 }
657 strbuf_release(&git_protocol);
658}
659
660/*
661 * Locate canonical hostname and its IP address.
662 */
663static void lookup_hostname(struct hostinfo *hi)
664{
665 if (!hi->hostname_lookup_done && hi->hostname.len) {
666#ifndef NO_IPV6
667 struct addrinfo hints;
668 struct addrinfo *ai;
669 int gai;
670 static char addrbuf[HOST_NAME_MAX + 1];
671
672 memset(&hints, 0, sizeof(hints));
673 hints.ai_flags = AI_CANONNAME;
674
675 gai = getaddrinfo(hi->hostname.buf, NULL, &hints, &ai);
676 if (!gai) {
677 struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
678
679 inet_ntop(AF_INET, &sin_addr->sin_addr,
680 addrbuf, sizeof(addrbuf));
681 strbuf_addstr(&hi->ip_address, addrbuf);
682
683 if (ai->ai_canonname)
684 sanitize_client(&hi->canon_hostname,
685 ai->ai_canonname);
686 else
687 strbuf_addbuf(&hi->canon_hostname,
688 &hi->ip_address);
689
690 freeaddrinfo(ai);
691 }
692#else
693 struct hostent *hent;
694 struct sockaddr_in sa;
695 char **ap;
696 static char addrbuf[HOST_NAME_MAX + 1];
697
698 hent = gethostbyname(hi->hostname.buf);
699 if (hent) {
700 ap = hent->h_addr_list;
701 memset(&sa, 0, sizeof sa);
702 sa.sin_family = hent->h_addrtype;
703 sa.sin_port = htons(0);
704 memcpy(&sa.sin_addr, *ap, hent->h_length);
705
706 inet_ntop(hent->h_addrtype, &sa.sin_addr,
707 addrbuf, sizeof(addrbuf));
708
709 sanitize_client(&hi->canon_hostname, hent->h_name);
710 strbuf_addstr(&hi->ip_address, addrbuf);
711 }
712#endif
713 hi->hostname_lookup_done = 1;
714 }
715}
716
717static void hostinfo_clear(struct hostinfo *hi)
718{
719 strbuf_release(&hi->hostname);
720 strbuf_release(&hi->canon_hostname);
721 strbuf_release(&hi->ip_address);
722 strbuf_release(&hi->tcp_port);
723}
724
725static void set_keep_alive(int sockfd)
726{
727 int ka = 1;
728
729 if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0) {
730 if (errno != ENOTSOCK)
731 logerror("unable to set SO_KEEPALIVE on socket: %s",
732 strerror(errno));
733 }
734}
735
736static int execute(void)
737{
738 char *line = packet_buffer;
739 int pktlen, len;
740 char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
741 struct hostinfo hi = HOSTINFO_INIT;
742 struct strvec env = STRVEC_INIT;
743
744 if (addr)
745 loginfo("Connection from %s:%s", addr, port);
746
747 set_keep_alive(0);
748 alarm(init_timeout ? init_timeout : timeout);
749 pktlen = packet_read(0, packet_buffer, sizeof(packet_buffer), 0);
750 alarm(0);
751
752 len = strlen(line);
753 if (len && line[len-1] == '\n')
754 line[len-1] = 0;
755
756 /* parse additional args hidden behind a NUL byte */
757 if (len != pktlen)
758 parse_extra_args(&hi, &env, line + len + 1, pktlen - len - 1);
759
760 for (size_t i = 0; i < ARRAY_SIZE(daemon_service); i++) {
761 struct daemon_service *s = &(daemon_service[i]);
762 const char *arg;
763
764 if (skip_prefix(line, "git-", &arg) &&
765 skip_prefix(arg, s->name, &arg) &&
766 *arg++ == ' ') {
767 /*
768 * Note: The directory here is probably context sensitive,
769 * and might depend on the actual service being performed.
770 */
771 int rc = run_service(arg, s, &hi, &env);
772 hostinfo_clear(&hi);
773 strvec_clear(&env);
774 return rc;
775 }
776 }
777
778 hostinfo_clear(&hi);
779 strvec_clear(&env);
780 logerror("Protocol error: '%s'", line);
781 return -1;
782}
783
784static int addrcmp(const struct sockaddr_storage *s1,
785 const struct sockaddr_storage *s2)
786{
787 const struct sockaddr *sa1 = (const struct sockaddr*) s1;
788 const struct sockaddr *sa2 = (const struct sockaddr*) s2;
789
790 if (sa1->sa_family != sa2->sa_family)
791 return sa1->sa_family - sa2->sa_family;
792 if (sa1->sa_family == AF_INET)
793 return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
794 &((struct sockaddr_in *)s2)->sin_addr,
795 sizeof(struct in_addr));
796#ifndef NO_IPV6
797 if (sa1->sa_family == AF_INET6)
798 return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
799 &((struct sockaddr_in6 *)s2)->sin6_addr,
800 sizeof(struct in6_addr));
801#endif
802 return 0;
803}
804
805static unsigned int max_connections = 32;
806static unsigned int live_children;
807
808static struct child {
809 struct child *next;
810 struct child_process cld;
811 struct sockaddr_storage address;
812} *firstborn;
813
814static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
815{
816 struct child *newborn, **cradle;
817
818 CALLOC_ARRAY(newborn, 1);
819 live_children++;
820 memcpy(&newborn->cld, cld, sizeof(*cld));
821 memcpy(&newborn->address, addr, addrlen);
822 for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
823 if (!addrcmp(&(*cradle)->address, &newborn->address))
824 break;
825 newborn->next = *cradle;
826 *cradle = newborn;
827}
828
829/*
830 * This gets called if the number of connections grows
831 * past "max_connections".
832 *
833 * We kill the newest connection from a duplicate IP.
834 */
835static void kill_some_child(void)
836{
837 const struct child *blanket, *next;
838
839 if (!(blanket = firstborn))
840 return;
841
842 for (; (next = blanket->next); blanket = next)
843 if (!addrcmp(&blanket->address, &next->address)) {
844 kill(blanket->cld.pid, SIGTERM);
845 break;
846 }
847}
848
849static void check_dead_children(void)
850{
851 int status;
852 pid_t pid;
853
854 struct child **cradle, *blanket;
855 for (cradle = &firstborn; (blanket = *cradle);)
856 if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
857 const char *dead = "";
858 if (status)
859 dead = " (with error)";
860 loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
861
862 /* remove the child */
863 *cradle = blanket->next;
864 live_children--;
865 child_process_clear(&blanket->cld);
866 free(blanket);
867 } else
868 cradle = &blanket->next;
869}
870
871static struct strvec cld_argv = STRVEC_INIT;
872static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
873{
874 struct child_process cld = CHILD_PROCESS_INIT;
875
876 if (max_connections && live_children >= max_connections) {
877 kill_some_child();
878 sleep(1); /* give it some time to die */
879 check_dead_children();
880 if (live_children >= max_connections) {
881 close(incoming);
882 logerror("Too many children, dropping connection");
883 return;
884 }
885 }
886
887 if (addr->sa_family == AF_INET) {
888 char buf[128] = "";
889 struct sockaddr_in *sin_addr = (void *) addr;
890 inet_ntop(addr->sa_family, &sin_addr->sin_addr, buf, sizeof(buf));
891 strvec_pushf(&cld.env, "REMOTE_ADDR=%s", buf);
892 strvec_pushf(&cld.env, "REMOTE_PORT=%d",
893 ntohs(sin_addr->sin_port));
894#ifndef NO_IPV6
895 } else if (addr->sa_family == AF_INET6) {
896 char buf[128] = "";
897 struct sockaddr_in6 *sin6_addr = (void *) addr;
898 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(buf));
899 strvec_pushf(&cld.env, "REMOTE_ADDR=[%s]", buf);
900 strvec_pushf(&cld.env, "REMOTE_PORT=%d",
901 ntohs(sin6_addr->sin6_port));
902#endif
903 }
904
905 strvec_pushv(&cld.args, cld_argv.v);
906 cld.in = incoming;
907 cld.out = dup(incoming);
908
909 if (start_command(&cld))
910 logerror("unable to fork");
911 else
912 add_child(&cld, addr, addrlen);
913}
914
915static void child_handler(int signo UNUSED)
916{
917 /*
918 * Otherwise empty handler because systemcalls should get interrupted
919 * upon signal receipt.
920 */
921}
922
923static int set_reuse_addr(int sockfd)
924{
925 int on = 1;
926
927 if (!reuseaddr)
928 return 0;
929 return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
930 &on, sizeof(on));
931}
932
933struct socketlist {
934 int *list;
935 size_t nr;
936 size_t alloc;
937};
938
939static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
940{
941#ifdef NO_IPV6
942 static char ip[INET_ADDRSTRLEN];
943#else
944 static char ip[INET6_ADDRSTRLEN];
945#endif
946
947 switch (family) {
948#ifndef NO_IPV6
949 case AF_INET6:
950 inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
951 break;
952#endif
953 case AF_INET:
954 inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
955 break;
956 default:
957 xsnprintf(ip, sizeof(ip), "<unknown>");
958 }
959 return ip;
960}
961
962#ifndef NO_IPV6
963
964static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
965{
966 int socknum = 0;
967 char pbuf[NI_MAXSERV];
968 struct addrinfo hints, *ai0, *ai;
969 int gai;
970 long flags;
971
972 xsnprintf(pbuf, sizeof(pbuf), "%d", listen_port);
973 memset(&hints, 0, sizeof(hints));
974 hints.ai_family = AF_UNSPEC;
975 hints.ai_socktype = SOCK_STREAM;
976 hints.ai_protocol = IPPROTO_TCP;
977 hints.ai_flags = AI_PASSIVE;
978
979 gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
980 if (gai) {
981 logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
982 return 0;
983 }
984
985 for (ai = ai0; ai; ai = ai->ai_next) {
986 int sockfd;
987
988 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
989 if (sockfd < 0)
990 continue;
991
992#ifdef IPV6_V6ONLY
993 if (ai->ai_family == AF_INET6) {
994 int on = 1;
995 setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
996 &on, sizeof(on));
997 /* Note: error is not fatal */
998 }
999#endif
1000
1001 if (set_reuse_addr(sockfd)) {
1002 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1003 close(sockfd);
1004 continue;
1005 }
1006
1007 set_keep_alive(sockfd);
1008
1009 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
1010 logerror("Could not bind to %s: %s",
1011 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1012 strerror(errno));
1013 close(sockfd);
1014 continue; /* not fatal */
1015 }
1016 if (listen(sockfd, 5) < 0) {
1017 logerror("Could not listen to %s: %s",
1018 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1019 strerror(errno));
1020 close(sockfd);
1021 continue; /* not fatal */
1022 }
1023
1024 flags = fcntl(sockfd, F_GETFD, 0);
1025 if (flags >= 0)
1026 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1027
1028 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1029 socklist->list[socklist->nr++] = sockfd;
1030 socknum++;
1031 }
1032
1033 freeaddrinfo(ai0);
1034
1035 return socknum;
1036}
1037
1038#else /* NO_IPV6 */
1039
1040static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
1041{
1042 struct sockaddr_in sin;
1043 int sockfd;
1044 long flags;
1045
1046 memset(&sin, 0, sizeof sin);
1047 sin.sin_family = AF_INET;
1048 sin.sin_port = htons(listen_port);
1049
1050 if (listen_addr) {
1051 /* Well, host better be an IP address here. */
1052 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
1053 return 0;
1054 } else {
1055 sin.sin_addr.s_addr = htonl(INADDR_ANY);
1056 }
1057
1058 sockfd = socket(AF_INET, SOCK_STREAM, 0);
1059 if (sockfd < 0)
1060 return 0;
1061
1062 if (set_reuse_addr(sockfd)) {
1063 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1064 close(sockfd);
1065 return 0;
1066 }
1067
1068 set_keep_alive(sockfd);
1069
1070 if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
1071 logerror("Could not bind to %s: %s",
1072 ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1073 strerror(errno));
1074 close(sockfd);
1075 return 0;
1076 }
1077
1078 if (listen(sockfd, 5) < 0) {
1079 logerror("Could not listen to %s: %s",
1080 ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1081 strerror(errno));
1082 close(sockfd);
1083 return 0;
1084 }
1085
1086 flags = fcntl(sockfd, F_GETFD, 0);
1087 if (flags >= 0)
1088 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1089
1090 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1091 socklist->list[socklist->nr++] = sockfd;
1092 return 1;
1093}
1094
1095#endif
1096
1097static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
1098{
1099 if (!listen_addr->nr)
1100 setup_named_sock(NULL, listen_port, socklist);
1101 else {
1102 int socknum;
1103 for (size_t i = 0; i < listen_addr->nr; i++) {
1104 socknum = setup_named_sock(listen_addr->items[i].string,
1105 listen_port, socklist);
1106
1107 if (socknum == 0)
1108 logerror("unable to allocate any listen sockets for host %s on port %u",
1109 listen_addr->items[i].string, listen_port);
1110 }
1111 }
1112}
1113
1114static int service_loop(struct socketlist *socklist)
1115{
1116 struct sigaction sa;
1117 struct pollfd *pfd;
1118
1119 CALLOC_ARRAY(pfd, socklist->nr);
1120
1121 for (size_t i = 0; i < socklist->nr; i++) {
1122 pfd[i].fd = socklist->list[i];
1123 pfd[i].events = POLLIN;
1124 }
1125
1126 sigemptyset(&sa.sa_mask);
1127 sa.sa_flags = SA_NOCLDSTOP;
1128 sa.sa_handler = child_handler;
1129 sigaction(SIGCHLD, &sa, NULL);
1130
1131 for (;;) {
1132 check_dead_children();
1133
1134 if (poll(pfd, socklist->nr, -1) < 0) {
1135 if (errno != EINTR) {
1136 logerror("Poll failed, resuming: %s",
1137 strerror(errno));
1138 sleep(1);
1139 }
1140 continue;
1141 }
1142
1143 for (size_t i = 0; i < socklist->nr; i++) {
1144 if (pfd[i].revents & POLLIN) {
1145 union {
1146 struct sockaddr sa;
1147 struct sockaddr_in sai;
1148#ifndef NO_IPV6
1149 struct sockaddr_in6 sai6;
1150#endif
1151 } ss;
1152 socklen_t sslen = sizeof(ss);
1153 int incoming;
1154 int retry = 3;
1155
1156 redo:
1157 incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1158 if (incoming < 0) {
1159 switch (errno) {
1160 case EINTR:
1161 if (--retry)
1162 goto redo;
1163
1164 /* fallthrough */
1165 case EAGAIN:
1166 case ECONNABORTED:
1167 continue;
1168 default:
1169 die_errno("accept returned");
1170 }
1171 }
1172 handle(incoming, &ss.sa, sslen);
1173 }
1174 }
1175 }
1176}
1177
1178#ifdef NO_POSIX_GOODIES
1179
1180struct credentials;
1181
1182static void drop_privileges(struct credentials *cred UNUSED)
1183{
1184 /* nothing */
1185}
1186
1187static struct credentials *prepare_credentials(const char *user_name UNUSED,
1188 const char *group_name UNUSED)
1189{
1190 die("--user not supported on this platform");
1191}
1192
1193#else
1194
1195struct credentials {
1196 struct passwd *pass;
1197 gid_t gid;
1198};
1199
1200static void drop_privileges(struct credentials *cred)
1201{
1202 if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1203 setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1204 die("cannot drop privileges");
1205}
1206
1207static struct credentials *prepare_credentials(const char *user_name,
1208 const char *group_name)
1209{
1210 static struct credentials c;
1211
1212 c.pass = getpwnam(user_name);
1213 if (!c.pass)
1214 die("user not found - %s", user_name);
1215
1216 if (!group_name)
1217 c.gid = c.pass->pw_gid;
1218 else {
1219 struct group *group = getgrnam(group_name);
1220 if (!group)
1221 die("group not found - %s", group_name);
1222
1223 c.gid = group->gr_gid;
1224 }
1225
1226 return &c;
1227}
1228#endif
1229
1230static int serve(struct string_list *listen_addr, int listen_port,
1231 struct credentials *cred)
1232{
1233 struct socketlist socklist = { NULL, 0, 0 };
1234
1235 socksetup(listen_addr, listen_port, &socklist);
1236 if (socklist.nr == 0)
1237 die("unable to allocate any listen sockets on port %u",
1238 listen_port);
1239
1240 drop_privileges(cred);
1241
1242 loginfo("Ready to rumble");
1243
1244 return service_loop(&socklist);
1245}
1246
1247int cmd_main(int argc, const char **argv)
1248{
1249 int listen_port = 0;
1250 struct string_list listen_addr = STRING_LIST_INIT_DUP;
1251 int serve_mode = 0, inetd_mode = 0;
1252 const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1253 int detach = 0;
1254 struct credentials *cred = NULL;
1255 int i;
1256 int ret;
1257
1258 for (i = 1; i < argc; i++) {
1259 const char *arg = argv[i];
1260 const char *v;
1261
1262 if (skip_prefix(arg, "--listen=", &v)) {
1263 string_list_append_nodup(&listen_addr, xstrdup_tolower(v));
1264 continue;
1265 }
1266 if (skip_prefix(arg, "--port=", &v)) {
1267 char *end;
1268 unsigned long n;
1269 n = strtoul(v, &end, 0);
1270 if (*v && !*end) {
1271 listen_port = n;
1272 continue;
1273 }
1274 }
1275 if (!strcmp(arg, "--serve")) {
1276 serve_mode = 1;
1277 continue;
1278 }
1279 if (!strcmp(arg, "--inetd")) {
1280 inetd_mode = 1;
1281 continue;
1282 }
1283 if (!strcmp(arg, "--verbose")) {
1284 verbose = 1;
1285 continue;
1286 }
1287 if (!strcmp(arg, "--syslog")) {
1288 log_destination = LOG_DESTINATION_SYSLOG;
1289 continue;
1290 }
1291 if (skip_prefix(arg, "--log-destination=", &v)) {
1292 if (!strcmp(v, "syslog")) {
1293 log_destination = LOG_DESTINATION_SYSLOG;
1294 continue;
1295 } else if (!strcmp(v, "stderr")) {
1296 log_destination = LOG_DESTINATION_STDERR;
1297 continue;
1298 } else if (!strcmp(v, "none")) {
1299 log_destination = LOG_DESTINATION_NONE;
1300 continue;
1301 } else
1302 die("unknown log destination '%s'", v);
1303 }
1304 if (!strcmp(arg, "--export-all")) {
1305 export_all_trees = 1;
1306 continue;
1307 }
1308 if (skip_prefix(arg, "--access-hook=", &v)) {
1309 access_hook = v;
1310 continue;
1311 }
1312 if (skip_prefix(arg, "--timeout=", &v)) {
1313 if (strtoul_ui(v, 10, &timeout))
1314 die(_("invalid timeout '%s', expecting a non-negative integer"), v);
1315 continue;
1316 }
1317 if (skip_prefix(arg, "--init-timeout=", &v)) {
1318 if (strtoul_ui(v, 10, &init_timeout))
1319 die(_("invalid init-timeout '%s', expecting a non-negative integer"), v);
1320 continue;
1321 }
1322 if (skip_prefix(arg, "--max-connections=", &v)) {
1323 int parsed_value;
1324 if (strtol_i(v, 10, &parsed_value))
1325 die(_("invalid max-connections '%s', expecting an integer"), v);
1326 /* A negative value indicates unlimited children. */
1327 max_connections = parsed_value < 0 ? 0 : parsed_value;
1328 continue;
1329 }
1330 if (!strcmp(arg, "--strict-paths")) {
1331 strict_paths = 1;
1332 continue;
1333 }
1334 if (skip_prefix(arg, "--base-path=", &v)) {
1335 base_path = v;
1336 continue;
1337 }
1338 if (!strcmp(arg, "--base-path-relaxed")) {
1339 base_path_relaxed = 1;
1340 continue;
1341 }
1342 if (skip_prefix(arg, "--interpolated-path=", &v)) {
1343 interpolated_path = v;
1344 continue;
1345 }
1346 if (!strcmp(arg, "--reuseaddr")) {
1347 reuseaddr = 1;
1348 continue;
1349 }
1350 if (!strcmp(arg, "--user-path")) {
1351 user_path = "";
1352 continue;
1353 }
1354 if (skip_prefix(arg, "--user-path=", &v)) {
1355 user_path = v;
1356 continue;
1357 }
1358 if (skip_prefix(arg, "--pid-file=", &v)) {
1359 pid_file = v;
1360 continue;
1361 }
1362 if (!strcmp(arg, "--detach")) {
1363 detach = 1;
1364 continue;
1365 }
1366 if (skip_prefix(arg, "--user=", &v)) {
1367 user_name = v;
1368 continue;
1369 }
1370 if (skip_prefix(arg, "--group=", &v)) {
1371 group_name = v;
1372 continue;
1373 }
1374 if (skip_prefix(arg, "--enable=", &v)) {
1375 enable_service(v, 1);
1376 continue;
1377 }
1378 if (skip_prefix(arg, "--disable=", &v)) {
1379 enable_service(v, 0);
1380 continue;
1381 }
1382 if (skip_prefix(arg, "--allow-override=", &v)) {
1383 make_service_overridable(v, 1);
1384 continue;
1385 }
1386 if (skip_prefix(arg, "--forbid-override=", &v)) {
1387 make_service_overridable(v, 0);
1388 continue;
1389 }
1390 if (!strcmp(arg, "--informative-errors")) {
1391 informative_errors = 1;
1392 continue;
1393 }
1394 if (!strcmp(arg, "--no-informative-errors")) {
1395 informative_errors = 0;
1396 continue;
1397 }
1398 if (!strcmp(arg, "--")) {
1399 ok_paths = &argv[i+1];
1400 break;
1401 } else if (arg[0] != '-') {
1402 ok_paths = &argv[i];
1403 break;
1404 }
1405
1406 usage(daemon_usage);
1407 }
1408
1409 if (log_destination == LOG_DESTINATION_UNSET) {
1410 if (inetd_mode || detach)
1411 log_destination = LOG_DESTINATION_SYSLOG;
1412 else
1413 log_destination = LOG_DESTINATION_STDERR;
1414 }
1415
1416 if (log_destination == LOG_DESTINATION_SYSLOG) {
1417 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1418 set_die_routine(daemon_die);
1419 } else
1420 /* avoid splitting a message in the middle */
1421 setvbuf(stderr, NULL, _IOFBF, 4096);
1422
1423 if (inetd_mode && (detach || group_name || user_name))
1424 die("--detach, --user and --group are incompatible with --inetd");
1425
1426 if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1427 die("--listen= and --port= are incompatible with --inetd");
1428 else if (listen_port == 0)
1429 listen_port = DEFAULT_GIT_PORT;
1430
1431 if (group_name && !user_name)
1432 die("--group supplied without --user");
1433
1434 if (user_name)
1435 cred = prepare_credentials(user_name, group_name);
1436
1437 if (strict_paths && (!ok_paths || !*ok_paths))
1438 die("option --strict-paths requires '<directory>' arguments");
1439
1440 if (base_path && !is_directory(base_path))
1441 die("base-path '%s' does not exist or is not a directory",
1442 base_path);
1443
1444 if (log_destination != LOG_DESTINATION_STDERR) {
1445 if (!freopen("/dev/null", "w", stderr))
1446 die_errno("failed to redirect stderr to /dev/null");
1447 }
1448
1449 if (inetd_mode || serve_mode) {
1450 ret = execute();
1451 } else {
1452 if (detach) {
1453 if (daemonize())
1454 die("--detach not supported on this platform");
1455 }
1456
1457 if (pid_file)
1458 write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
1459
1460 /* prepare argv for serving-processes */
1461 strvec_push(&cld_argv, argv[0]); /* git-daemon */
1462 strvec_push(&cld_argv, "--serve");
1463 for (i = 1; i < argc; ++i)
1464 strvec_push(&cld_argv, argv[i]);
1465
1466 ret = serve(&listen_addr, listen_port, cred);
1467 }
1468
1469 string_list_clear(&listen_addr, 0);
1470 return ret;
1471}