daemon.c: fix condition for redirecting stderr
[git] / daemon.c
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 argv_array *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 argv_array *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         argv_array_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 argv_array *env)
480 {
481         struct child_process cld = CHILD_PROCESS_INIT;
482         argv_array_pushl(&cld.args, "upload-pack", "--strict", NULL);
483         argv_array_pushf(&cld.args, "--timeout=%u", timeout);
484
485         argv_array_pushv(&cld.env_array, env->argv);
486
487         return run_service_command(&cld);
488 }
489
490 static int upload_archive(const struct argv_array *env)
491 {
492         struct child_process cld = CHILD_PROCESS_INIT;
493         argv_array_push(&cld.args, "upload-archive");
494
495         argv_array_pushv(&cld.env_array, env->argv);
496
497         return run_service_command(&cld);
498 }
499
500 static int receive_pack(const struct argv_array *env)
501 {
502         struct child_process cld = CHILD_PROCESS_INIT;
503         argv_array_push(&cld.args, "receive-pack");
504
505         argv_array_pushv(&cld.env_array, env->argv);
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  * arguemnt, or 'extra_args' if there is no host arguemnt.
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                         if (*val) {
615                                 /* Split <host>:<port> at colon. */
616                                 char *host;
617                                 char *port;
618                                 parse_host_and_port(val, &host, &port);
619                                 if (port)
620                                         sanitize_client(&hi->tcp_port, port);
621                                 canonicalize_client(&hi->hostname, host);
622                                 hi->hostname_lookup_done = 0;
623                         }
624
625                         /* On to the next one */
626                         extra_args = val + vallen;
627                 }
628                 if (extra_args < end && *extra_args)
629                         die("Invalid request");
630         }
631
632         return extra_args;
633 }
634
635 static void parse_extra_args(struct hostinfo *hi, struct argv_array *env,
636                              char *extra_args, int buflen)
637 {
638         const char *end = extra_args + buflen;
639         struct strbuf git_protocol = STRBUF_INIT;
640
641         /* First look for the host argument */
642         extra_args = parse_host_arg(hi, extra_args, buflen);
643
644         /* Look for additional arguments places after a second NUL byte */
645         for (; extra_args < end; extra_args += strlen(extra_args) + 1) {
646                 const char *arg = extra_args;
647
648                 /*
649                  * Parse the extra arguments, adding most to 'git_protocol'
650                  * which will be used to set the 'GIT_PROTOCOL' envvar in the
651                  * service that will be run.
652                  *
653                  * If there ends up being a particular arg in the future that
654                  * git-daemon needs to parse specificly (like the 'host' arg)
655                  * then it can be parsed here and not added to 'git_protocol'.
656                  */
657                 if (*arg) {
658                         if (git_protocol.len > 0)
659                                 strbuf_addch(&git_protocol, ':');
660                         strbuf_addstr(&git_protocol, arg);
661                 }
662         }
663
664         if (git_protocol.len > 0)
665                 argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=%s",
666                                  git_protocol.buf);
667         strbuf_release(&git_protocol);
668 }
669
670 /*
671  * Locate canonical hostname and its IP address.
672  */
673 static void lookup_hostname(struct hostinfo *hi)
674 {
675         if (!hi->hostname_lookup_done && hi->hostname.len) {
676 #ifndef NO_IPV6
677                 struct addrinfo hints;
678                 struct addrinfo *ai;
679                 int gai;
680                 static char addrbuf[HOST_NAME_MAX + 1];
681
682                 memset(&hints, 0, sizeof(hints));
683                 hints.ai_flags = AI_CANONNAME;
684
685                 gai = getaddrinfo(hi->hostname.buf, NULL, &hints, &ai);
686                 if (!gai) {
687                         struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
688
689                         inet_ntop(AF_INET, &sin_addr->sin_addr,
690                                   addrbuf, sizeof(addrbuf));
691                         strbuf_addstr(&hi->ip_address, addrbuf);
692
693                         if (ai->ai_canonname)
694                                 sanitize_client(&hi->canon_hostname,
695                                                 ai->ai_canonname);
696                         else
697                                 strbuf_addbuf(&hi->canon_hostname,
698                                               &hi->ip_address);
699
700                         freeaddrinfo(ai);
701                 }
702 #else
703                 struct hostent *hent;
704                 struct sockaddr_in sa;
705                 char **ap;
706                 static char addrbuf[HOST_NAME_MAX + 1];
707
708                 hent = gethostbyname(hi->hostname.buf);
709                 if (hent) {
710                         ap = hent->h_addr_list;
711                         memset(&sa, 0, sizeof sa);
712                         sa.sin_family = hent->h_addrtype;
713                         sa.sin_port = htons(0);
714                         memcpy(&sa.sin_addr, *ap, hent->h_length);
715
716                         inet_ntop(hent->h_addrtype, &sa.sin_addr,
717                                   addrbuf, sizeof(addrbuf));
718
719                         sanitize_client(&hi->canon_hostname, hent->h_name);
720                         strbuf_addstr(&hi->ip_address, addrbuf);
721                 }
722 #endif
723                 hi->hostname_lookup_done = 1;
724         }
725 }
726
727 static void hostinfo_init(struct hostinfo *hi)
728 {
729         memset(hi, 0, sizeof(*hi));
730         strbuf_init(&hi->hostname, 0);
731         strbuf_init(&hi->canon_hostname, 0);
732         strbuf_init(&hi->ip_address, 0);
733         strbuf_init(&hi->tcp_port, 0);
734 }
735
736 static void hostinfo_clear(struct hostinfo *hi)
737 {
738         strbuf_release(&hi->hostname);
739         strbuf_release(&hi->canon_hostname);
740         strbuf_release(&hi->ip_address);
741         strbuf_release(&hi->tcp_port);
742 }
743
744 static void set_keep_alive(int sockfd)
745 {
746         int ka = 1;
747
748         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0) {
749                 if (errno != ENOTSOCK)
750                         logerror("unable to set SO_KEEPALIVE on socket: %s",
751                                 strerror(errno));
752         }
753 }
754
755 static int execute(void)
756 {
757         char *line = packet_buffer;
758         int pktlen, len, i;
759         char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
760         struct hostinfo hi;
761         struct argv_array env = ARGV_ARRAY_INIT;
762
763         hostinfo_init(&hi);
764
765         if (addr)
766                 loginfo("Connection from %s:%s", addr, port);
767
768         set_keep_alive(0);
769         alarm(init_timeout ? init_timeout : timeout);
770         pktlen = packet_read(0, NULL, NULL, packet_buffer, sizeof(packet_buffer), 0);
771         alarm(0);
772
773         len = strlen(line);
774         if (pktlen != len)
775                 loginfo("Extended attributes (%d bytes) exist <%.*s>",
776                         (int) pktlen - len,
777                         (int) pktlen - len, line + len + 1);
778         if (len && line[len-1] == '\n') {
779                 line[--len] = 0;
780                 pktlen--;
781         }
782
783         /* parse additional args hidden behind a NUL byte */
784         if (len != pktlen)
785                 parse_extra_args(&hi, &env, line + len + 1, pktlen - len - 1);
786
787         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
788                 struct daemon_service *s = &(daemon_service[i]);
789                 const char *arg;
790
791                 if (skip_prefix(line, "git-", &arg) &&
792                     skip_prefix(arg, s->name, &arg) &&
793                     *arg++ == ' ') {
794                         /*
795                          * Note: The directory here is probably context sensitive,
796                          * and might depend on the actual service being performed.
797                          */
798                         int rc = run_service(arg, s, &hi, &env);
799                         hostinfo_clear(&hi);
800                         argv_array_clear(&env);
801                         return rc;
802                 }
803         }
804
805         hostinfo_clear(&hi);
806         argv_array_clear(&env);
807         logerror("Protocol error: '%s'", line);
808         return -1;
809 }
810
811 static int addrcmp(const struct sockaddr_storage *s1,
812     const struct sockaddr_storage *s2)
813 {
814         const struct sockaddr *sa1 = (const struct sockaddr*) s1;
815         const struct sockaddr *sa2 = (const struct sockaddr*) s2;
816
817         if (sa1->sa_family != sa2->sa_family)
818                 return sa1->sa_family - sa2->sa_family;
819         if (sa1->sa_family == AF_INET)
820                 return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
821                     &((struct sockaddr_in *)s2)->sin_addr,
822                     sizeof(struct in_addr));
823 #ifndef NO_IPV6
824         if (sa1->sa_family == AF_INET6)
825                 return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
826                     &((struct sockaddr_in6 *)s2)->sin6_addr,
827                     sizeof(struct in6_addr));
828 #endif
829         return 0;
830 }
831
832 static int max_connections = 32;
833
834 static unsigned int live_children;
835
836 static struct child {
837         struct child *next;
838         struct child_process cld;
839         struct sockaddr_storage address;
840 } *firstborn;
841
842 static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
843 {
844         struct child *newborn, **cradle;
845
846         newborn = xcalloc(1, sizeof(*newborn));
847         live_children++;
848         memcpy(&newborn->cld, cld, sizeof(*cld));
849         memcpy(&newborn->address, addr, addrlen);
850         for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
851                 if (!addrcmp(&(*cradle)->address, &newborn->address))
852                         break;
853         newborn->next = *cradle;
854         *cradle = newborn;
855 }
856
857 /*
858  * This gets called if the number of connections grows
859  * past "max_connections".
860  *
861  * We kill the newest connection from a duplicate IP.
862  */
863 static void kill_some_child(void)
864 {
865         const struct child *blanket, *next;
866
867         if (!(blanket = firstborn))
868                 return;
869
870         for (; (next = blanket->next); blanket = next)
871                 if (!addrcmp(&blanket->address, &next->address)) {
872                         kill(blanket->cld.pid, SIGTERM);
873                         break;
874                 }
875 }
876
877 static void check_dead_children(void)
878 {
879         int status;
880         pid_t pid;
881
882         struct child **cradle, *blanket;
883         for (cradle = &firstborn; (blanket = *cradle);)
884                 if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
885                         const char *dead = "";
886                         if (status)
887                                 dead = " (with error)";
888                         loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
889
890                         /* remove the child */
891                         *cradle = blanket->next;
892                         live_children--;
893                         child_process_clear(&blanket->cld);
894                         free(blanket);
895                 } else
896                         cradle = &blanket->next;
897 }
898
899 static struct argv_array cld_argv = ARGV_ARRAY_INIT;
900 static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
901 {
902         struct child_process cld = CHILD_PROCESS_INIT;
903
904         if (max_connections && live_children >= max_connections) {
905                 kill_some_child();
906                 sleep(1);  /* give it some time to die */
907                 check_dead_children();
908                 if (live_children >= max_connections) {
909                         close(incoming);
910                         logerror("Too many children, dropping connection");
911                         return;
912                 }
913         }
914
915         if (addr->sa_family == AF_INET) {
916                 char buf[128] = "";
917                 struct sockaddr_in *sin_addr = (void *) addr;
918                 inet_ntop(addr->sa_family, &sin_addr->sin_addr, buf, sizeof(buf));
919                 argv_array_pushf(&cld.env_array, "REMOTE_ADDR=%s", buf);
920                 argv_array_pushf(&cld.env_array, "REMOTE_PORT=%d",
921                                  ntohs(sin_addr->sin_port));
922 #ifndef NO_IPV6
923         } else if (addr->sa_family == AF_INET6) {
924                 char buf[128] = "";
925                 struct sockaddr_in6 *sin6_addr = (void *) addr;
926                 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(buf));
927                 argv_array_pushf(&cld.env_array, "REMOTE_ADDR=[%s]", buf);
928                 argv_array_pushf(&cld.env_array, "REMOTE_PORT=%d",
929                                  ntohs(sin6_addr->sin6_port));
930 #endif
931         }
932
933         cld.argv = cld_argv.argv;
934         cld.in = incoming;
935         cld.out = dup(incoming);
936
937         if (start_command(&cld))
938                 logerror("unable to fork");
939         else
940                 add_child(&cld, addr, addrlen);
941 }
942
943 static void child_handler(int signo)
944 {
945         /*
946          * Otherwise empty handler because systemcalls will get interrupted
947          * upon signal receipt
948          * SysV needs the handler to be rearmed
949          */
950         signal(SIGCHLD, child_handler);
951 }
952
953 static int set_reuse_addr(int sockfd)
954 {
955         int on = 1;
956
957         if (!reuseaddr)
958                 return 0;
959         return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
960                           &on, sizeof(on));
961 }
962
963 struct socketlist {
964         int *list;
965         size_t nr;
966         size_t alloc;
967 };
968
969 static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
970 {
971 #ifdef NO_IPV6
972         static char ip[INET_ADDRSTRLEN];
973 #else
974         static char ip[INET6_ADDRSTRLEN];
975 #endif
976
977         switch (family) {
978 #ifndef NO_IPV6
979         case AF_INET6:
980                 inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
981                 break;
982 #endif
983         case AF_INET:
984                 inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
985                 break;
986         default:
987                 xsnprintf(ip, sizeof(ip), "<unknown>");
988         }
989         return ip;
990 }
991
992 #ifndef NO_IPV6
993
994 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
995 {
996         int socknum = 0;
997         char pbuf[NI_MAXSERV];
998         struct addrinfo hints, *ai0, *ai;
999         int gai;
1000         long flags;
1001
1002         xsnprintf(pbuf, sizeof(pbuf), "%d", listen_port);
1003         memset(&hints, 0, sizeof(hints));
1004         hints.ai_family = AF_UNSPEC;
1005         hints.ai_socktype = SOCK_STREAM;
1006         hints.ai_protocol = IPPROTO_TCP;
1007         hints.ai_flags = AI_PASSIVE;
1008
1009         gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
1010         if (gai) {
1011                 logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
1012                 return 0;
1013         }
1014
1015         for (ai = ai0; ai; ai = ai->ai_next) {
1016                 int sockfd;
1017
1018                 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1019                 if (sockfd < 0)
1020                         continue;
1021                 if (sockfd >= FD_SETSIZE) {
1022                         logerror("Socket descriptor too large");
1023                         close(sockfd);
1024                         continue;
1025                 }
1026
1027 #ifdef IPV6_V6ONLY
1028                 if (ai->ai_family == AF_INET6) {
1029                         int on = 1;
1030                         setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
1031                                    &on, sizeof(on));
1032                         /* Note: error is not fatal */
1033                 }
1034 #endif
1035
1036                 if (set_reuse_addr(sockfd)) {
1037                         logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1038                         close(sockfd);
1039                         continue;
1040                 }
1041
1042                 set_keep_alive(sockfd);
1043
1044                 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
1045                         logerror("Could not bind to %s: %s",
1046                                  ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1047                                  strerror(errno));
1048                         close(sockfd);
1049                         continue;       /* not fatal */
1050                 }
1051                 if (listen(sockfd, 5) < 0) {
1052                         logerror("Could not listen to %s: %s",
1053                                  ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1054                                  strerror(errno));
1055                         close(sockfd);
1056                         continue;       /* not fatal */
1057                 }
1058
1059                 flags = fcntl(sockfd, F_GETFD, 0);
1060                 if (flags >= 0)
1061                         fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1062
1063                 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1064                 socklist->list[socklist->nr++] = sockfd;
1065                 socknum++;
1066         }
1067
1068         freeaddrinfo(ai0);
1069
1070         return socknum;
1071 }
1072
1073 #else /* NO_IPV6 */
1074
1075 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
1076 {
1077         struct sockaddr_in sin;
1078         int sockfd;
1079         long flags;
1080
1081         memset(&sin, 0, sizeof sin);
1082         sin.sin_family = AF_INET;
1083         sin.sin_port = htons(listen_port);
1084
1085         if (listen_addr) {
1086                 /* Well, host better be an IP address here. */
1087                 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
1088                         return 0;
1089         } else {
1090                 sin.sin_addr.s_addr = htonl(INADDR_ANY);
1091         }
1092
1093         sockfd = socket(AF_INET, SOCK_STREAM, 0);
1094         if (sockfd < 0)
1095                 return 0;
1096
1097         if (set_reuse_addr(sockfd)) {
1098                 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1099                 close(sockfd);
1100                 return 0;
1101         }
1102
1103         set_keep_alive(sockfd);
1104
1105         if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
1106                 logerror("Could not bind to %s: %s",
1107                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1108                          strerror(errno));
1109                 close(sockfd);
1110                 return 0;
1111         }
1112
1113         if (listen(sockfd, 5) < 0) {
1114                 logerror("Could not listen to %s: %s",
1115                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1116                          strerror(errno));
1117                 close(sockfd);
1118                 return 0;
1119         }
1120
1121         flags = fcntl(sockfd, F_GETFD, 0);
1122         if (flags >= 0)
1123                 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1124
1125         ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1126         socklist->list[socklist->nr++] = sockfd;
1127         return 1;
1128 }
1129
1130 #endif
1131
1132 static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
1133 {
1134         if (!listen_addr->nr)
1135                 setup_named_sock(NULL, listen_port, socklist);
1136         else {
1137                 int i, socknum;
1138                 for (i = 0; i < listen_addr->nr; i++) {
1139                         socknum = setup_named_sock(listen_addr->items[i].string,
1140                                                    listen_port, socklist);
1141
1142                         if (socknum == 0)
1143                                 logerror("unable to allocate any listen sockets for host %s on port %u",
1144                                          listen_addr->items[i].string, listen_port);
1145                 }
1146         }
1147 }
1148
1149 static int service_loop(struct socketlist *socklist)
1150 {
1151         struct pollfd *pfd;
1152         int i;
1153
1154         pfd = xcalloc(socklist->nr, sizeof(struct pollfd));
1155
1156         for (i = 0; i < socklist->nr; i++) {
1157                 pfd[i].fd = socklist->list[i];
1158                 pfd[i].events = POLLIN;
1159         }
1160
1161         signal(SIGCHLD, child_handler);
1162
1163         for (;;) {
1164                 int i;
1165
1166                 check_dead_children();
1167
1168                 if (poll(pfd, socklist->nr, -1) < 0) {
1169                         if (errno != EINTR) {
1170                                 logerror("Poll failed, resuming: %s",
1171                                       strerror(errno));
1172                                 sleep(1);
1173                         }
1174                         continue;
1175                 }
1176
1177                 for (i = 0; i < socklist->nr; i++) {
1178                         if (pfd[i].revents & POLLIN) {
1179                                 union {
1180                                         struct sockaddr sa;
1181                                         struct sockaddr_in sai;
1182 #ifndef NO_IPV6
1183                                         struct sockaddr_in6 sai6;
1184 #endif
1185                                 } ss;
1186                                 socklen_t sslen = sizeof(ss);
1187                                 int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1188                                 if (incoming < 0) {
1189                                         switch (errno) {
1190                                         case EAGAIN:
1191                                         case EINTR:
1192                                         case ECONNABORTED:
1193                                                 continue;
1194                                         default:
1195                                                 die_errno("accept returned");
1196                                         }
1197                                 }
1198                                 handle(incoming, &ss.sa, sslen);
1199                         }
1200                 }
1201         }
1202 }
1203
1204 #ifdef NO_POSIX_GOODIES
1205
1206 struct credentials;
1207
1208 static void drop_privileges(struct credentials *cred)
1209 {
1210         /* nothing */
1211 }
1212
1213 static struct credentials *prepare_credentials(const char *user_name,
1214     const char *group_name)
1215 {
1216         die("--user not supported on this platform");
1217 }
1218
1219 #else
1220
1221 struct credentials {
1222         struct passwd *pass;
1223         gid_t gid;
1224 };
1225
1226 static void drop_privileges(struct credentials *cred)
1227 {
1228         if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1229             setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1230                 die("cannot drop privileges");
1231 }
1232
1233 static struct credentials *prepare_credentials(const char *user_name,
1234     const char *group_name)
1235 {
1236         static struct credentials c;
1237
1238         c.pass = getpwnam(user_name);
1239         if (!c.pass)
1240                 die("user not found - %s", user_name);
1241
1242         if (!group_name)
1243                 c.gid = c.pass->pw_gid;
1244         else {
1245                 struct group *group = getgrnam(group_name);
1246                 if (!group)
1247                         die("group not found - %s", group_name);
1248
1249                 c.gid = group->gr_gid;
1250         }
1251
1252         return &c;
1253 }
1254 #endif
1255
1256 static int serve(struct string_list *listen_addr, int listen_port,
1257     struct credentials *cred)
1258 {
1259         struct socketlist socklist = { NULL, 0, 0 };
1260
1261         socksetup(listen_addr, listen_port, &socklist);
1262         if (socklist.nr == 0)
1263                 die("unable to allocate any listen sockets on port %u",
1264                     listen_port);
1265
1266         drop_privileges(cred);
1267
1268         loginfo("Ready to rumble");
1269
1270         return service_loop(&socklist);
1271 }
1272
1273 int cmd_main(int argc, const char **argv)
1274 {
1275         int listen_port = 0;
1276         struct string_list listen_addr = STRING_LIST_INIT_NODUP;
1277         int serve_mode = 0, inetd_mode = 0;
1278         const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1279         int detach = 0;
1280         struct credentials *cred = NULL;
1281         int i;
1282
1283         for (i = 1; i < argc; i++) {
1284                 const char *arg = argv[i];
1285                 const char *v;
1286
1287                 if (skip_prefix(arg, "--listen=", &v)) {
1288                         string_list_append(&listen_addr, xstrdup_tolower(v));
1289                         continue;
1290                 }
1291                 if (skip_prefix(arg, "--port=", &v)) {
1292                         char *end;
1293                         unsigned long n;
1294                         n = strtoul(v, &end, 0);
1295                         if (*v && !*end) {
1296                                 listen_port = n;
1297                                 continue;
1298                         }
1299                 }
1300                 if (!strcmp(arg, "--serve")) {
1301                         serve_mode = 1;
1302                         continue;
1303                 }
1304                 if (!strcmp(arg, "--inetd")) {
1305                         inetd_mode = 1;
1306                         continue;
1307                 }
1308                 if (!strcmp(arg, "--verbose")) {
1309                         verbose = 1;
1310                         continue;
1311                 }
1312                 if (!strcmp(arg, "--syslog")) {
1313                         log_destination = LOG_DESTINATION_SYSLOG;
1314                         continue;
1315                 }
1316                 if (skip_prefix(arg, "--log-destination=", &v)) {
1317                         if (!strcmp(v, "syslog")) {
1318                                 log_destination = LOG_DESTINATION_SYSLOG;
1319                                 continue;
1320                         } else if (!strcmp(v, "stderr")) {
1321                                 log_destination = LOG_DESTINATION_STDERR;
1322                                 continue;
1323                         } else if (!strcmp(v, "none")) {
1324                                 log_destination = LOG_DESTINATION_NONE;
1325                                 continue;
1326                         } else
1327                                 die("unknown log destination '%s'", v);
1328                 }
1329                 if (!strcmp(arg, "--export-all")) {
1330                         export_all_trees = 1;
1331                         continue;
1332                 }
1333                 if (skip_prefix(arg, "--access-hook=", &v)) {
1334                         access_hook = v;
1335                         continue;
1336                 }
1337                 if (skip_prefix(arg, "--timeout=", &v)) {
1338                         timeout = atoi(v);
1339                         continue;
1340                 }
1341                 if (skip_prefix(arg, "--init-timeout=", &v)) {
1342                         init_timeout = atoi(v);
1343                         continue;
1344                 }
1345                 if (skip_prefix(arg, "--max-connections=", &v)) {
1346                         max_connections = atoi(v);
1347                         if (max_connections < 0)
1348                                 max_connections = 0;            /* unlimited */
1349                         continue;
1350                 }
1351                 if (!strcmp(arg, "--strict-paths")) {
1352                         strict_paths = 1;
1353                         continue;
1354                 }
1355                 if (skip_prefix(arg, "--base-path=", &v)) {
1356                         base_path = v;
1357                         continue;
1358                 }
1359                 if (!strcmp(arg, "--base-path-relaxed")) {
1360                         base_path_relaxed = 1;
1361                         continue;
1362                 }
1363                 if (skip_prefix(arg, "--interpolated-path=", &v)) {
1364                         interpolated_path = v;
1365                         continue;
1366                 }
1367                 if (!strcmp(arg, "--reuseaddr")) {
1368                         reuseaddr = 1;
1369                         continue;
1370                 }
1371                 if (!strcmp(arg, "--user-path")) {
1372                         user_path = "";
1373                         continue;
1374                 }
1375                 if (skip_prefix(arg, "--user-path=", &v)) {
1376                         user_path = v;
1377                         continue;
1378                 }
1379                 if (skip_prefix(arg, "--pid-file=", &v)) {
1380                         pid_file = v;
1381                         continue;
1382                 }
1383                 if (!strcmp(arg, "--detach")) {
1384                         detach = 1;
1385                         continue;
1386                 }
1387                 if (skip_prefix(arg, "--user=", &v)) {
1388                         user_name = v;
1389                         continue;
1390                 }
1391                 if (skip_prefix(arg, "--group=", &v)) {
1392                         group_name = v;
1393                         continue;
1394                 }
1395                 if (skip_prefix(arg, "--enable=", &v)) {
1396                         enable_service(v, 1);
1397                         continue;
1398                 }
1399                 if (skip_prefix(arg, "--disable=", &v)) {
1400                         enable_service(v, 0);
1401                         continue;
1402                 }
1403                 if (skip_prefix(arg, "--allow-override=", &v)) {
1404                         make_service_overridable(v, 1);
1405                         continue;
1406                 }
1407                 if (skip_prefix(arg, "--forbid-override=", &v)) {
1408                         make_service_overridable(v, 0);
1409                         continue;
1410                 }
1411                 if (!strcmp(arg, "--informative-errors")) {
1412                         informative_errors = 1;
1413                         continue;
1414                 }
1415                 if (!strcmp(arg, "--no-informative-errors")) {
1416                         informative_errors = 0;
1417                         continue;
1418                 }
1419                 if (!strcmp(arg, "--")) {
1420                         ok_paths = &argv[i+1];
1421                         break;
1422                 } else if (arg[0] != '-') {
1423                         ok_paths = &argv[i];
1424                         break;
1425                 }
1426
1427                 usage(daemon_usage);
1428         }
1429
1430         if (log_destination == LOG_DESTINATION_UNSET) {
1431                 if (inetd_mode || detach)
1432                         log_destination = LOG_DESTINATION_SYSLOG;
1433                 else
1434                         log_destination = LOG_DESTINATION_STDERR;
1435         }
1436
1437         if (log_destination == LOG_DESTINATION_SYSLOG) {
1438                 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1439                 set_die_routine(daemon_die);
1440         } else
1441                 /* avoid splitting a message in the middle */
1442                 setvbuf(stderr, NULL, _IOFBF, 4096);
1443
1444         if (inetd_mode && (detach || group_name || user_name))
1445                 die("--detach, --user and --group are incompatible with --inetd");
1446
1447         if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1448                 die("--listen= and --port= are incompatible with --inetd");
1449         else if (listen_port == 0)
1450                 listen_port = DEFAULT_GIT_PORT;
1451
1452         if (group_name && !user_name)
1453                 die("--group supplied without --user");
1454
1455         if (user_name)
1456                 cred = prepare_credentials(user_name, group_name);
1457
1458         if (strict_paths && (!ok_paths || !*ok_paths))
1459                 die("option --strict-paths requires a whitelist");
1460
1461         if (base_path && !is_directory(base_path))
1462                 die("base-path '%s' does not exist or is not a directory",
1463                     base_path);
1464
1465         if (log_destination != LOG_DESTINATION_STDERR) {
1466                 if (!freopen("/dev/null", "w", stderr))
1467                         die_errno("failed to redirect stderr to /dev/null");
1468         }
1469
1470         if (inetd_mode || serve_mode)
1471                 return execute();
1472
1473         if (detach) {
1474                 if (daemonize())
1475                         die("--detach not supported on this platform");
1476         }
1477
1478         if (pid_file)
1479                 write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
1480
1481         /* prepare argv for serving-processes */
1482         argv_array_push(&cld_argv, argv[0]); /* git-daemon */
1483         argv_array_push(&cld_argv, "--serve");
1484         for (i = 1; i < argc; ++i)
1485                 argv_array_push(&cld_argv, argv[i]);
1486
1487         return serve(&listen_addr, listen_port, cred);
1488 }