Merge branch 'jt/http-redact-cookies' into maint
[git.git] / daemon.c
blobe37e343d0aec37fd74e7bdf694b99f59d022690a
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"
8 #ifdef NO_INITGROUPS
9 #define initgroups(x, y) (0) /* nothing */
10 #endif
12 static int log_syslog;
13 static int verbose;
14 static int reuseaddr;
15 static int informative_errors;
17 static const char daemon_usage[] =
18 "git daemon [--verbose] [--syslog] [--export-all]\n"
19 " [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n"
20 " [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
21 " [--user-path | --user-path=<path>]\n"
22 " [--interpolated-path=<path>]\n"
23 " [--reuseaddr] [--pid-file=<file>]\n"
24 " [--(enable|disable|allow-override|forbid-override)=<service>]\n"
25 " [--access-hook=<path>]\n"
26 " [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
27 " [--detach] [--user=<user> [--group=<group>]]\n"
28 " [<directory>...]";
30 /* List of acceptable pathname prefixes */
31 static const char **ok_paths;
32 static int strict_paths;
34 /* If this is set, git-daemon-export-ok is not required */
35 static int export_all_trees;
37 /* Take all paths relative to this one if non-NULL */
38 static const char *base_path;
39 static const char *interpolated_path;
40 static int base_path_relaxed;
42 /* If defined, ~user notation is allowed and the string is inserted
43 * after ~user/. E.g. a request to git://host/~alice/frotz would
44 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
46 static const char *user_path;
48 /* Timeout, and initial timeout */
49 static unsigned int timeout;
50 static unsigned int init_timeout;
52 struct hostinfo {
53 struct strbuf hostname;
54 struct strbuf canon_hostname;
55 struct strbuf ip_address;
56 struct strbuf tcp_port;
57 unsigned int hostname_lookup_done:1;
58 unsigned int saw_extended_args:1;
61 static void lookup_hostname(struct hostinfo *hi);
63 static const char *get_canon_hostname(struct hostinfo *hi)
65 lookup_hostname(hi);
66 return hi->canon_hostname.buf;
69 static const char *get_ip_address(struct hostinfo *hi)
71 lookup_hostname(hi);
72 return hi->ip_address.buf;
75 static void logreport(int priority, const char *err, va_list params)
77 if (log_syslog) {
78 char buf[1024];
79 vsnprintf(buf, sizeof(buf), err, params);
80 syslog(priority, "%s", buf);
81 } else {
83 * Since stderr is set to buffered mode, the
84 * logging of different processes will not overlap
85 * unless they overflow the (rather big) buffers.
87 fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
88 vfprintf(stderr, err, params);
89 fputc('\n', stderr);
90 fflush(stderr);
94 __attribute__((format (printf, 1, 2)))
95 static void logerror(const char *err, ...)
97 va_list params;
98 va_start(params, err);
99 logreport(LOG_ERR, err, params);
100 va_end(params);
103 __attribute__((format (printf, 1, 2)))
104 static void loginfo(const char *err, ...)
106 va_list params;
107 if (!verbose)
108 return;
109 va_start(params, err);
110 logreport(LOG_INFO, err, params);
111 va_end(params);
114 static void NORETURN daemon_die(const char *err, va_list params)
116 logreport(LOG_ERR, err, params);
117 exit(1);
120 struct expand_path_context {
121 const char *directory;
122 struct hostinfo *hostinfo;
125 static size_t expand_path(struct strbuf *sb, const char *placeholder, void *ctx)
127 struct expand_path_context *context = ctx;
128 struct hostinfo *hi = context->hostinfo;
130 switch (placeholder[0]) {
131 case 'H':
132 strbuf_addbuf(sb, &hi->hostname);
133 return 1;
134 case 'C':
135 if (placeholder[1] == 'H') {
136 strbuf_addstr(sb, get_canon_hostname(hi));
137 return 2;
139 break;
140 case 'I':
141 if (placeholder[1] == 'P') {
142 strbuf_addstr(sb, get_ip_address(hi));
143 return 2;
145 break;
146 case 'P':
147 strbuf_addbuf(sb, &hi->tcp_port);
148 return 1;
149 case 'D':
150 strbuf_addstr(sb, context->directory);
151 return 1;
153 return 0;
156 static const char *path_ok(const char *directory, struct hostinfo *hi)
158 static char rpath[PATH_MAX];
159 static char interp_path[PATH_MAX];
160 size_t rlen;
161 const char *path;
162 const char *dir;
164 dir = directory;
166 if (daemon_avoid_alias(dir)) {
167 logerror("'%s': aliased", dir);
168 return NULL;
171 if (*dir == '~') {
172 if (!user_path) {
173 logerror("'%s': User-path not allowed", dir);
174 return NULL;
176 if (*user_path) {
177 /* Got either "~alice" or "~alice/foo";
178 * rewrite them to "~alice/%s" or
179 * "~alice/%s/foo".
181 int namlen, restlen = strlen(dir);
182 const char *slash = strchr(dir, '/');
183 if (!slash)
184 slash = dir + restlen;
185 namlen = slash - dir;
186 restlen -= namlen;
187 loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
188 rlen = snprintf(rpath, sizeof(rpath), "%.*s/%s%.*s",
189 namlen, dir, user_path, restlen, slash);
190 if (rlen >= sizeof(rpath)) {
191 logerror("user-path too large: %s", rpath);
192 return NULL;
194 dir = rpath;
197 else if (interpolated_path && hi->saw_extended_args) {
198 struct strbuf expanded_path = STRBUF_INIT;
199 struct expand_path_context context;
201 context.directory = directory;
202 context.hostinfo = hi;
204 if (*dir != '/') {
205 /* Allow only absolute */
206 logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
207 return NULL;
210 strbuf_expand(&expanded_path, interpolated_path,
211 expand_path, &context);
213 rlen = strlcpy(interp_path, expanded_path.buf,
214 sizeof(interp_path));
215 if (rlen >= sizeof(interp_path)) {
216 logerror("interpolated path too large: %s",
217 interp_path);
218 return NULL;
221 strbuf_release(&expanded_path);
222 loginfo("Interpolated dir '%s'", interp_path);
224 dir = interp_path;
226 else if (base_path) {
227 if (*dir != '/') {
228 /* Allow only absolute */
229 logerror("'%s': Non-absolute path denied (base-path active)", dir);
230 return NULL;
232 rlen = snprintf(rpath, sizeof(rpath), "%s%s", base_path, dir);
233 if (rlen >= sizeof(rpath)) {
234 logerror("base-path too large: %s", rpath);
235 return NULL;
237 dir = rpath;
240 path = enter_repo(dir, strict_paths);
241 if (!path && base_path && base_path_relaxed) {
243 * if we fail and base_path_relaxed is enabled, try without
244 * prefixing the base path
246 dir = directory;
247 path = enter_repo(dir, strict_paths);
250 if (!path) {
251 logerror("'%s' does not appear to be a git repository", dir);
252 return NULL;
255 if ( ok_paths && *ok_paths ) {
256 const char **pp;
257 int pathlen = strlen(path);
259 /* The validation is done on the paths after enter_repo
260 * appends optional {.git,.git/.git} and friends, but
261 * it does not use getcwd(). So if your /pub is
262 * a symlink to /mnt/pub, you can whitelist /pub and
263 * do not have to say /mnt/pub.
264 * Do not say /pub/.
266 for ( pp = ok_paths ; *pp ; pp++ ) {
267 int len = strlen(*pp);
268 if (len <= pathlen &&
269 !memcmp(*pp, path, len) &&
270 (path[len] == '\0' ||
271 (!strict_paths && path[len] == '/')))
272 return path;
275 else {
276 /* be backwards compatible */
277 if (!strict_paths)
278 return path;
281 logerror("'%s': not in whitelist", path);
282 return NULL; /* Fallthrough. Deny by default */
285 typedef int (*daemon_service_fn)(const struct argv_array *env);
286 struct daemon_service {
287 const char *name;
288 const char *config_name;
289 daemon_service_fn fn;
290 int enabled;
291 int overridable;
294 static int daemon_error(const char *dir, const char *msg)
296 if (!informative_errors)
297 msg = "access denied or repository not exported";
298 packet_write_fmt(1, "ERR %s: %s", msg, dir);
299 return -1;
302 static const char *access_hook;
304 static int run_access_hook(struct daemon_service *service, const char *dir,
305 const char *path, struct hostinfo *hi)
307 struct child_process child = CHILD_PROCESS_INIT;
308 struct strbuf buf = STRBUF_INIT;
309 const char *argv[8];
310 const char **arg = argv;
311 char *eol;
312 int seen_errors = 0;
314 *arg++ = access_hook;
315 *arg++ = service->name;
316 *arg++ = path;
317 *arg++ = hi->hostname.buf;
318 *arg++ = get_canon_hostname(hi);
319 *arg++ = get_ip_address(hi);
320 *arg++ = hi->tcp_port.buf;
321 *arg = NULL;
323 child.use_shell = 1;
324 child.argv = argv;
325 child.no_stdin = 1;
326 child.no_stderr = 1;
327 child.out = -1;
328 if (start_command(&child)) {
329 logerror("daemon access hook '%s' failed to start",
330 access_hook);
331 goto error_return;
333 if (strbuf_read(&buf, child.out, 0) < 0) {
334 logerror("failed to read from pipe to daemon access hook '%s'",
335 access_hook);
336 strbuf_reset(&buf);
337 seen_errors = 1;
339 if (close(child.out) < 0) {
340 logerror("failed to close pipe to daemon access hook '%s'",
341 access_hook);
342 seen_errors = 1;
344 if (finish_command(&child))
345 seen_errors = 1;
347 if (!seen_errors) {
348 strbuf_release(&buf);
349 return 0;
352 error_return:
353 strbuf_ltrim(&buf);
354 if (!buf.len)
355 strbuf_addstr(&buf, "service rejected");
356 eol = strchr(buf.buf, '\n');
357 if (eol)
358 *eol = '\0';
359 errno = EACCES;
360 daemon_error(dir, buf.buf);
361 strbuf_release(&buf);
362 return -1;
365 static int run_service(const char *dir, struct daemon_service *service,
366 struct hostinfo *hi, const struct argv_array *env)
368 const char *path;
369 int enabled = service->enabled;
370 struct strbuf var = STRBUF_INIT;
372 loginfo("Request %s for '%s'", service->name, dir);
374 if (!enabled && !service->overridable) {
375 logerror("'%s': service not enabled.", service->name);
376 errno = EACCES;
377 return daemon_error(dir, "service not enabled");
380 if (!(path = path_ok(dir, hi)))
381 return daemon_error(dir, "no such repository");
384 * Security on the cheap.
386 * We want a readable HEAD, usable "objects" directory, and
387 * a "git-daemon-export-ok" flag that says that the other side
388 * is ok with us doing this.
390 * path_ok() uses enter_repo() and does whitelist checking.
391 * We only need to make sure the repository is exported.
394 if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
395 logerror("'%s': repository not exported.", path);
396 errno = EACCES;
397 return daemon_error(dir, "repository not exported");
400 if (service->overridable) {
401 strbuf_addf(&var, "daemon.%s", service->config_name);
402 git_config_get_bool(var.buf, &enabled);
403 strbuf_release(&var);
405 if (!enabled) {
406 logerror("'%s': service not enabled for '%s'",
407 service->name, path);
408 errno = EACCES;
409 return daemon_error(dir, "service not enabled");
413 * Optionally, a hook can choose to deny access to the
414 * repository depending on the phase of the moon.
416 if (access_hook && run_access_hook(service, dir, path, hi))
417 return -1;
420 * We'll ignore SIGTERM from now on, we have a
421 * good client.
423 signal(SIGTERM, SIG_IGN);
425 return service->fn(env);
428 static void copy_to_log(int fd)
430 struct strbuf line = STRBUF_INIT;
431 FILE *fp;
433 fp = fdopen(fd, "r");
434 if (fp == NULL) {
435 logerror("fdopen of error channel failed");
436 close(fd);
437 return;
440 while (strbuf_getline_lf(&line, fp) != EOF) {
441 logerror("%s", line.buf);
442 strbuf_setlen(&line, 0);
445 strbuf_release(&line);
446 fclose(fp);
449 static int run_service_command(struct child_process *cld)
451 argv_array_push(&cld->args, ".");
452 cld->git_cmd = 1;
453 cld->err = -1;
454 if (start_command(cld))
455 return -1;
457 close(0);
458 close(1);
460 copy_to_log(cld->err);
462 return finish_command(cld);
465 static int upload_pack(const struct argv_array *env)
467 struct child_process cld = CHILD_PROCESS_INIT;
468 argv_array_pushl(&cld.args, "upload-pack", "--strict", NULL);
469 argv_array_pushf(&cld.args, "--timeout=%u", timeout);
471 argv_array_pushv(&cld.env_array, env->argv);
473 return run_service_command(&cld);
476 static int upload_archive(const struct argv_array *env)
478 struct child_process cld = CHILD_PROCESS_INIT;
479 argv_array_push(&cld.args, "upload-archive");
481 argv_array_pushv(&cld.env_array, env->argv);
483 return run_service_command(&cld);
486 static int receive_pack(const struct argv_array *env)
488 struct child_process cld = CHILD_PROCESS_INIT;
489 argv_array_push(&cld.args, "receive-pack");
491 argv_array_pushv(&cld.env_array, env->argv);
493 return run_service_command(&cld);
496 static struct daemon_service daemon_service[] = {
497 { "upload-archive", "uploadarch", upload_archive, 0, 1 },
498 { "upload-pack", "uploadpack", upload_pack, 1, 1 },
499 { "receive-pack", "receivepack", receive_pack, 0, 1 },
502 static void enable_service(const char *name, int ena)
504 int i;
505 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
506 if (!strcmp(daemon_service[i].name, name)) {
507 daemon_service[i].enabled = ena;
508 return;
511 die("No such service %s", name);
514 static void make_service_overridable(const char *name, int ena)
516 int i;
517 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
518 if (!strcmp(daemon_service[i].name, name)) {
519 daemon_service[i].overridable = ena;
520 return;
523 die("No such service %s", name);
526 static void parse_host_and_port(char *hostport, char **host,
527 char **port)
529 if (*hostport == '[') {
530 char *end;
532 end = strchr(hostport, ']');
533 if (!end)
534 die("Invalid request ('[' without ']')");
535 *end = '\0';
536 *host = hostport + 1;
537 if (!end[1])
538 *port = NULL;
539 else if (end[1] == ':')
540 *port = end + 2;
541 else
542 die("Garbage after end of host part");
543 } else {
544 *host = hostport;
545 *port = strrchr(hostport, ':');
546 if (*port) {
547 **port = '\0';
548 ++*port;
554 * Sanitize a string from the client so that it's OK to be inserted into a
555 * filesystem path. Specifically, we disallow slashes, runs of "..", and
556 * trailing and leading dots, which means that the client cannot escape
557 * our base path via ".." traversal.
559 static void sanitize_client(struct strbuf *out, const char *in)
561 for (; *in; in++) {
562 if (*in == '/')
563 continue;
564 if (*in == '.' && (!out->len || out->buf[out->len - 1] == '.'))
565 continue;
566 strbuf_addch(out, *in);
569 while (out->len && out->buf[out->len - 1] == '.')
570 strbuf_setlen(out, out->len - 1);
574 * Like sanitize_client, but we also perform any canonicalization
575 * to make life easier on the admin.
577 static void canonicalize_client(struct strbuf *out, const char *in)
579 sanitize_client(out, in);
580 strbuf_tolower(out);
584 * Read the host as supplied by the client connection.
586 * Returns a pointer to the character after the NUL byte terminating the host
587 * arguemnt, or 'extra_args' if there is no host arguemnt.
589 static char *parse_host_arg(struct hostinfo *hi, char *extra_args, int buflen)
591 char *val;
592 int vallen;
593 char *end = extra_args + buflen;
595 if (extra_args < end && *extra_args) {
596 hi->saw_extended_args = 1;
597 if (strncasecmp("host=", extra_args, 5) == 0) {
598 val = extra_args + 5;
599 vallen = strlen(val) + 1;
600 if (*val) {
601 /* Split <host>:<port> at colon. */
602 char *host;
603 char *port;
604 parse_host_and_port(val, &host, &port);
605 if (port)
606 sanitize_client(&hi->tcp_port, port);
607 canonicalize_client(&hi->hostname, host);
608 hi->hostname_lookup_done = 0;
611 /* On to the next one */
612 extra_args = val + vallen;
614 if (extra_args < end && *extra_args)
615 die("Invalid request");
618 return extra_args;
621 static void parse_extra_args(struct hostinfo *hi, struct argv_array *env,
622 char *extra_args, int buflen)
624 const char *end = extra_args + buflen;
625 struct strbuf git_protocol = STRBUF_INIT;
627 /* First look for the host argument */
628 extra_args = parse_host_arg(hi, extra_args, buflen);
630 /* Look for additional arguments places after a second NUL byte */
631 for (; extra_args < end; extra_args += strlen(extra_args) + 1) {
632 const char *arg = extra_args;
635 * Parse the extra arguments, adding most to 'git_protocol'
636 * which will be used to set the 'GIT_PROTOCOL' envvar in the
637 * service that will be run.
639 * If there ends up being a particular arg in the future that
640 * git-daemon needs to parse specificly (like the 'host' arg)
641 * then it can be parsed here and not added to 'git_protocol'.
643 if (*arg) {
644 if (git_protocol.len > 0)
645 strbuf_addch(&git_protocol, ':');
646 strbuf_addstr(&git_protocol, arg);
650 if (git_protocol.len > 0)
651 argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=%s",
652 git_protocol.buf);
653 strbuf_release(&git_protocol);
657 * Locate canonical hostname and its IP address.
659 static void lookup_hostname(struct hostinfo *hi)
661 if (!hi->hostname_lookup_done && hi->hostname.len) {
662 #ifndef NO_IPV6
663 struct addrinfo hints;
664 struct addrinfo *ai;
665 int gai;
666 static char addrbuf[HOST_NAME_MAX + 1];
668 memset(&hints, 0, sizeof(hints));
669 hints.ai_flags = AI_CANONNAME;
671 gai = getaddrinfo(hi->hostname.buf, NULL, &hints, &ai);
672 if (!gai) {
673 struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
675 inet_ntop(AF_INET, &sin_addr->sin_addr,
676 addrbuf, sizeof(addrbuf));
677 strbuf_addstr(&hi->ip_address, addrbuf);
679 if (ai->ai_canonname)
680 sanitize_client(&hi->canon_hostname,
681 ai->ai_canonname);
682 else
683 strbuf_addbuf(&hi->canon_hostname,
684 &hi->ip_address);
686 freeaddrinfo(ai);
688 #else
689 struct hostent *hent;
690 struct sockaddr_in sa;
691 char **ap;
692 static char addrbuf[HOST_NAME_MAX + 1];
694 hent = gethostbyname(hi->hostname.buf);
695 if (hent) {
696 ap = hent->h_addr_list;
697 memset(&sa, 0, sizeof sa);
698 sa.sin_family = hent->h_addrtype;
699 sa.sin_port = htons(0);
700 memcpy(&sa.sin_addr, *ap, hent->h_length);
702 inet_ntop(hent->h_addrtype, &sa.sin_addr,
703 addrbuf, sizeof(addrbuf));
705 sanitize_client(&hi->canon_hostname, hent->h_name);
706 strbuf_addstr(&hi->ip_address, addrbuf);
708 #endif
709 hi->hostname_lookup_done = 1;
713 static void hostinfo_init(struct hostinfo *hi)
715 memset(hi, 0, sizeof(*hi));
716 strbuf_init(&hi->hostname, 0);
717 strbuf_init(&hi->canon_hostname, 0);
718 strbuf_init(&hi->ip_address, 0);
719 strbuf_init(&hi->tcp_port, 0);
722 static void hostinfo_clear(struct hostinfo *hi)
724 strbuf_release(&hi->hostname);
725 strbuf_release(&hi->canon_hostname);
726 strbuf_release(&hi->ip_address);
727 strbuf_release(&hi->tcp_port);
730 static void set_keep_alive(int sockfd)
732 int ka = 1;
734 if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0) {
735 if (errno != ENOTSOCK)
736 logerror("unable to set SO_KEEPALIVE on socket: %s",
737 strerror(errno));
741 static int execute(void)
743 char *line = packet_buffer;
744 int pktlen, len, i;
745 char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
746 struct hostinfo hi;
747 struct argv_array env = ARGV_ARRAY_INIT;
749 hostinfo_init(&hi);
751 if (addr)
752 loginfo("Connection from %s:%s", addr, port);
754 set_keep_alive(0);
755 alarm(init_timeout ? init_timeout : timeout);
756 pktlen = packet_read(0, NULL, NULL, packet_buffer, sizeof(packet_buffer), 0);
757 alarm(0);
759 len = strlen(line);
760 if (pktlen != len)
761 loginfo("Extended attributes (%d bytes) exist <%.*s>",
762 (int) pktlen - len,
763 (int) pktlen - len, line + len + 1);
764 if (len && line[len-1] == '\n') {
765 line[--len] = 0;
766 pktlen--;
769 /* parse additional args hidden behind a NUL byte */
770 if (len != pktlen)
771 parse_extra_args(&hi, &env, line + len + 1, pktlen - len - 1);
773 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
774 struct daemon_service *s = &(daemon_service[i]);
775 const char *arg;
777 if (skip_prefix(line, "git-", &arg) &&
778 skip_prefix(arg, s->name, &arg) &&
779 *arg++ == ' ') {
781 * Note: The directory here is probably context sensitive,
782 * and might depend on the actual service being performed.
784 int rc = run_service(arg, s, &hi, &env);
785 hostinfo_clear(&hi);
786 argv_array_clear(&env);
787 return rc;
791 hostinfo_clear(&hi);
792 argv_array_clear(&env);
793 logerror("Protocol error: '%s'", line);
794 return -1;
797 static int addrcmp(const struct sockaddr_storage *s1,
798 const struct sockaddr_storage *s2)
800 const struct sockaddr *sa1 = (const struct sockaddr*) s1;
801 const struct sockaddr *sa2 = (const struct sockaddr*) s2;
803 if (sa1->sa_family != sa2->sa_family)
804 return sa1->sa_family - sa2->sa_family;
805 if (sa1->sa_family == AF_INET)
806 return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
807 &((struct sockaddr_in *)s2)->sin_addr,
808 sizeof(struct in_addr));
809 #ifndef NO_IPV6
810 if (sa1->sa_family == AF_INET6)
811 return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
812 &((struct sockaddr_in6 *)s2)->sin6_addr,
813 sizeof(struct in6_addr));
814 #endif
815 return 0;
818 static int max_connections = 32;
820 static unsigned int live_children;
822 static struct child {
823 struct child *next;
824 struct child_process cld;
825 struct sockaddr_storage address;
826 } *firstborn;
828 static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
830 struct child *newborn, **cradle;
832 newborn = xcalloc(1, sizeof(*newborn));
833 live_children++;
834 memcpy(&newborn->cld, cld, sizeof(*cld));
835 memcpy(&newborn->address, addr, addrlen);
836 for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
837 if (!addrcmp(&(*cradle)->address, &newborn->address))
838 break;
839 newborn->next = *cradle;
840 *cradle = newborn;
844 * This gets called if the number of connections grows
845 * past "max_connections".
847 * We kill the newest connection from a duplicate IP.
849 static void kill_some_child(void)
851 const struct child *blanket, *next;
853 if (!(blanket = firstborn))
854 return;
856 for (; (next = blanket->next); blanket = next)
857 if (!addrcmp(&blanket->address, &next->address)) {
858 kill(blanket->cld.pid, SIGTERM);
859 break;
863 static void check_dead_children(void)
865 int status;
866 pid_t pid;
868 struct child **cradle, *blanket;
869 for (cradle = &firstborn; (blanket = *cradle);)
870 if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
871 const char *dead = "";
872 if (status)
873 dead = " (with error)";
874 loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
876 /* remove the child */
877 *cradle = blanket->next;
878 live_children--;
879 child_process_clear(&blanket->cld);
880 free(blanket);
881 } else
882 cradle = &blanket->next;
885 static struct argv_array cld_argv = ARGV_ARRAY_INIT;
886 static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
888 struct child_process cld = CHILD_PROCESS_INIT;
890 if (max_connections && live_children >= max_connections) {
891 kill_some_child();
892 sleep(1); /* give it some time to die */
893 check_dead_children();
894 if (live_children >= max_connections) {
895 close(incoming);
896 logerror("Too many children, dropping connection");
897 return;
901 if (addr->sa_family == AF_INET) {
902 char buf[128] = "";
903 struct sockaddr_in *sin_addr = (void *) addr;
904 inet_ntop(addr->sa_family, &sin_addr->sin_addr, buf, sizeof(buf));
905 argv_array_pushf(&cld.env_array, "REMOTE_ADDR=%s", buf);
906 argv_array_pushf(&cld.env_array, "REMOTE_PORT=%d",
907 ntohs(sin_addr->sin_port));
908 #ifndef NO_IPV6
909 } else if (addr->sa_family == AF_INET6) {
910 char buf[128] = "";
911 struct sockaddr_in6 *sin6_addr = (void *) addr;
912 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(buf));
913 argv_array_pushf(&cld.env_array, "REMOTE_ADDR=[%s]", buf);
914 argv_array_pushf(&cld.env_array, "REMOTE_PORT=%d",
915 ntohs(sin6_addr->sin6_port));
916 #endif
919 cld.argv = cld_argv.argv;
920 cld.in = incoming;
921 cld.out = dup(incoming);
923 if (start_command(&cld))
924 logerror("unable to fork");
925 else
926 add_child(&cld, addr, addrlen);
929 static void child_handler(int signo)
932 * Otherwise empty handler because systemcalls will get interrupted
933 * upon signal receipt
934 * SysV needs the handler to be rearmed
936 signal(SIGCHLD, child_handler);
939 static int set_reuse_addr(int sockfd)
941 int on = 1;
943 if (!reuseaddr)
944 return 0;
945 return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
946 &on, sizeof(on));
949 struct socketlist {
950 int *list;
951 size_t nr;
952 size_t alloc;
955 static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
957 #ifdef NO_IPV6
958 static char ip[INET_ADDRSTRLEN];
959 #else
960 static char ip[INET6_ADDRSTRLEN];
961 #endif
963 switch (family) {
964 #ifndef NO_IPV6
965 case AF_INET6:
966 inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
967 break;
968 #endif
969 case AF_INET:
970 inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
971 break;
972 default:
973 xsnprintf(ip, sizeof(ip), "<unknown>");
975 return ip;
978 #ifndef NO_IPV6
980 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
982 int socknum = 0;
983 char pbuf[NI_MAXSERV];
984 struct addrinfo hints, *ai0, *ai;
985 int gai;
986 long flags;
988 xsnprintf(pbuf, sizeof(pbuf), "%d", listen_port);
989 memset(&hints, 0, sizeof(hints));
990 hints.ai_family = AF_UNSPEC;
991 hints.ai_socktype = SOCK_STREAM;
992 hints.ai_protocol = IPPROTO_TCP;
993 hints.ai_flags = AI_PASSIVE;
995 gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
996 if (gai) {
997 logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
998 return 0;
1001 for (ai = ai0; ai; ai = ai->ai_next) {
1002 int sockfd;
1004 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1005 if (sockfd < 0)
1006 continue;
1007 if (sockfd >= FD_SETSIZE) {
1008 logerror("Socket descriptor too large");
1009 close(sockfd);
1010 continue;
1013 #ifdef IPV6_V6ONLY
1014 if (ai->ai_family == AF_INET6) {
1015 int on = 1;
1016 setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
1017 &on, sizeof(on));
1018 /* Note: error is not fatal */
1020 #endif
1022 if (set_reuse_addr(sockfd)) {
1023 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1024 close(sockfd);
1025 continue;
1028 set_keep_alive(sockfd);
1030 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
1031 logerror("Could not bind to %s: %s",
1032 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1033 strerror(errno));
1034 close(sockfd);
1035 continue; /* not fatal */
1037 if (listen(sockfd, 5) < 0) {
1038 logerror("Could not listen to %s: %s",
1039 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1040 strerror(errno));
1041 close(sockfd);
1042 continue; /* not fatal */
1045 flags = fcntl(sockfd, F_GETFD, 0);
1046 if (flags >= 0)
1047 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1049 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1050 socklist->list[socklist->nr++] = sockfd;
1051 socknum++;
1054 freeaddrinfo(ai0);
1056 return socknum;
1059 #else /* NO_IPV6 */
1061 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
1063 struct sockaddr_in sin;
1064 int sockfd;
1065 long flags;
1067 memset(&sin, 0, sizeof sin);
1068 sin.sin_family = AF_INET;
1069 sin.sin_port = htons(listen_port);
1071 if (listen_addr) {
1072 /* Well, host better be an IP address here. */
1073 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
1074 return 0;
1075 } else {
1076 sin.sin_addr.s_addr = htonl(INADDR_ANY);
1079 sockfd = socket(AF_INET, SOCK_STREAM, 0);
1080 if (sockfd < 0)
1081 return 0;
1083 if (set_reuse_addr(sockfd)) {
1084 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1085 close(sockfd);
1086 return 0;
1089 set_keep_alive(sockfd);
1091 if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
1092 logerror("Could not bind to %s: %s",
1093 ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1094 strerror(errno));
1095 close(sockfd);
1096 return 0;
1099 if (listen(sockfd, 5) < 0) {
1100 logerror("Could not listen to %s: %s",
1101 ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1102 strerror(errno));
1103 close(sockfd);
1104 return 0;
1107 flags = fcntl(sockfd, F_GETFD, 0);
1108 if (flags >= 0)
1109 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1111 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1112 socklist->list[socklist->nr++] = sockfd;
1113 return 1;
1116 #endif
1118 static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
1120 if (!listen_addr->nr)
1121 setup_named_sock(NULL, listen_port, socklist);
1122 else {
1123 int i, socknum;
1124 for (i = 0; i < listen_addr->nr; i++) {
1125 socknum = setup_named_sock(listen_addr->items[i].string,
1126 listen_port, socklist);
1128 if (socknum == 0)
1129 logerror("unable to allocate any listen sockets for host %s on port %u",
1130 listen_addr->items[i].string, listen_port);
1135 static int service_loop(struct socketlist *socklist)
1137 struct pollfd *pfd;
1138 int i;
1140 pfd = xcalloc(socklist->nr, sizeof(struct pollfd));
1142 for (i = 0; i < socklist->nr; i++) {
1143 pfd[i].fd = socklist->list[i];
1144 pfd[i].events = POLLIN;
1147 signal(SIGCHLD, child_handler);
1149 for (;;) {
1150 int i;
1152 check_dead_children();
1154 if (poll(pfd, socklist->nr, -1) < 0) {
1155 if (errno != EINTR) {
1156 logerror("Poll failed, resuming: %s",
1157 strerror(errno));
1158 sleep(1);
1160 continue;
1163 for (i = 0; i < socklist->nr; i++) {
1164 if (pfd[i].revents & POLLIN) {
1165 union {
1166 struct sockaddr sa;
1167 struct sockaddr_in sai;
1168 #ifndef NO_IPV6
1169 struct sockaddr_in6 sai6;
1170 #endif
1171 } ss;
1172 socklen_t sslen = sizeof(ss);
1173 int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1174 if (incoming < 0) {
1175 switch (errno) {
1176 case EAGAIN:
1177 case EINTR:
1178 case ECONNABORTED:
1179 continue;
1180 default:
1181 die_errno("accept returned");
1184 handle(incoming, &ss.sa, sslen);
1190 #ifdef NO_POSIX_GOODIES
1192 struct credentials;
1194 static void drop_privileges(struct credentials *cred)
1196 /* nothing */
1199 static struct credentials *prepare_credentials(const char *user_name,
1200 const char *group_name)
1202 die("--user not supported on this platform");
1205 #else
1207 struct credentials {
1208 struct passwd *pass;
1209 gid_t gid;
1212 static void drop_privileges(struct credentials *cred)
1214 if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1215 setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1216 die("cannot drop privileges");
1219 static struct credentials *prepare_credentials(const char *user_name,
1220 const char *group_name)
1222 static struct credentials c;
1224 c.pass = getpwnam(user_name);
1225 if (!c.pass)
1226 die("user not found - %s", user_name);
1228 if (!group_name)
1229 c.gid = c.pass->pw_gid;
1230 else {
1231 struct group *group = getgrnam(group_name);
1232 if (!group)
1233 die("group not found - %s", group_name);
1235 c.gid = group->gr_gid;
1238 return &c;
1240 #endif
1242 static int serve(struct string_list *listen_addr, int listen_port,
1243 struct credentials *cred)
1245 struct socketlist socklist = { NULL, 0, 0 };
1247 socksetup(listen_addr, listen_port, &socklist);
1248 if (socklist.nr == 0)
1249 die("unable to allocate any listen sockets on port %u",
1250 listen_port);
1252 drop_privileges(cred);
1254 loginfo("Ready to rumble");
1256 return service_loop(&socklist);
1259 int cmd_main(int argc, const char **argv)
1261 int listen_port = 0;
1262 struct string_list listen_addr = STRING_LIST_INIT_NODUP;
1263 int serve_mode = 0, inetd_mode = 0;
1264 const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1265 int detach = 0;
1266 struct credentials *cred = NULL;
1267 int i;
1269 for (i = 1; i < argc; i++) {
1270 const char *arg = argv[i];
1271 const char *v;
1273 if (skip_prefix(arg, "--listen=", &v)) {
1274 string_list_append(&listen_addr, xstrdup_tolower(v));
1275 continue;
1277 if (skip_prefix(arg, "--port=", &v)) {
1278 char *end;
1279 unsigned long n;
1280 n = strtoul(v, &end, 0);
1281 if (*v && !*end) {
1282 listen_port = n;
1283 continue;
1286 if (!strcmp(arg, "--serve")) {
1287 serve_mode = 1;
1288 continue;
1290 if (!strcmp(arg, "--inetd")) {
1291 inetd_mode = 1;
1292 log_syslog = 1;
1293 continue;
1295 if (!strcmp(arg, "--verbose")) {
1296 verbose = 1;
1297 continue;
1299 if (!strcmp(arg, "--syslog")) {
1300 log_syslog = 1;
1301 continue;
1303 if (!strcmp(arg, "--export-all")) {
1304 export_all_trees = 1;
1305 continue;
1307 if (skip_prefix(arg, "--access-hook=", &v)) {
1308 access_hook = v;
1309 continue;
1311 if (skip_prefix(arg, "--timeout=", &v)) {
1312 timeout = atoi(v);
1313 continue;
1315 if (skip_prefix(arg, "--init-timeout=", &v)) {
1316 init_timeout = atoi(v);
1317 continue;
1319 if (skip_prefix(arg, "--max-connections=", &v)) {
1320 max_connections = atoi(v);
1321 if (max_connections < 0)
1322 max_connections = 0; /* unlimited */
1323 continue;
1325 if (!strcmp(arg, "--strict-paths")) {
1326 strict_paths = 1;
1327 continue;
1329 if (skip_prefix(arg, "--base-path=", &v)) {
1330 base_path = v;
1331 continue;
1333 if (!strcmp(arg, "--base-path-relaxed")) {
1334 base_path_relaxed = 1;
1335 continue;
1337 if (skip_prefix(arg, "--interpolated-path=", &v)) {
1338 interpolated_path = v;
1339 continue;
1341 if (!strcmp(arg, "--reuseaddr")) {
1342 reuseaddr = 1;
1343 continue;
1345 if (!strcmp(arg, "--user-path")) {
1346 user_path = "";
1347 continue;
1349 if (skip_prefix(arg, "--user-path=", &v)) {
1350 user_path = v;
1351 continue;
1353 if (skip_prefix(arg, "--pid-file=", &v)) {
1354 pid_file = v;
1355 continue;
1357 if (!strcmp(arg, "--detach")) {
1358 detach = 1;
1359 log_syslog = 1;
1360 continue;
1362 if (skip_prefix(arg, "--user=", &v)) {
1363 user_name = v;
1364 continue;
1366 if (skip_prefix(arg, "--group=", &v)) {
1367 group_name = v;
1368 continue;
1370 if (skip_prefix(arg, "--enable=", &v)) {
1371 enable_service(v, 1);
1372 continue;
1374 if (skip_prefix(arg, "--disable=", &v)) {
1375 enable_service(v, 0);
1376 continue;
1378 if (skip_prefix(arg, "--allow-override=", &v)) {
1379 make_service_overridable(v, 1);
1380 continue;
1382 if (skip_prefix(arg, "--forbid-override=", &v)) {
1383 make_service_overridable(v, 0);
1384 continue;
1386 if (!strcmp(arg, "--informative-errors")) {
1387 informative_errors = 1;
1388 continue;
1390 if (!strcmp(arg, "--no-informative-errors")) {
1391 informative_errors = 0;
1392 continue;
1394 if (!strcmp(arg, "--")) {
1395 ok_paths = &argv[i+1];
1396 break;
1397 } else if (arg[0] != '-') {
1398 ok_paths = &argv[i];
1399 break;
1402 usage(daemon_usage);
1405 if (log_syslog) {
1406 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1407 set_die_routine(daemon_die);
1408 } else
1409 /* avoid splitting a message in the middle */
1410 setvbuf(stderr, NULL, _IOFBF, 4096);
1412 if (inetd_mode && (detach || group_name || user_name))
1413 die("--detach, --user and --group are incompatible with --inetd");
1415 if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1416 die("--listen= and --port= are incompatible with --inetd");
1417 else if (listen_port == 0)
1418 listen_port = DEFAULT_GIT_PORT;
1420 if (group_name && !user_name)
1421 die("--group supplied without --user");
1423 if (user_name)
1424 cred = prepare_credentials(user_name, group_name);
1426 if (strict_paths && (!ok_paths || !*ok_paths))
1427 die("option --strict-paths requires a whitelist");
1429 if (base_path && !is_directory(base_path))
1430 die("base-path '%s' does not exist or is not a directory",
1431 base_path);
1433 if (inetd_mode) {
1434 if (!freopen("/dev/null", "w", stderr))
1435 die_errno("failed to redirect stderr to /dev/null");
1438 if (inetd_mode || serve_mode)
1439 return execute();
1441 if (detach) {
1442 if (daemonize())
1443 die("--detach not supported on this platform");
1446 if (pid_file)
1447 write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
1449 /* prepare argv for serving-processes */
1450 argv_array_push(&cld_argv, argv[0]); /* git-daemon */
1451 argv_array_push(&cld_argv, "--serve");
1452 for (i = 1; i < argc; ++i)
1453 argv_array_push(&cld_argv, argv[i]);
1455 return serve(&listen_addr, listen_port, cred);