Code

Replace fork_with_pipe in bundle with run_command
[git.git] / daemon.c
1 #include "cache.h"
2 #include "pkt-line.h"
3 #include "exec_cmd.h"
4 #include "interpolate.h"
6 #include <syslog.h>
8 #ifndef HOST_NAME_MAX
9 #define HOST_NAME_MAX 256
10 #endif
12 static int log_syslog;
13 static int verbose;
14 static int reuseaddr;
16 static const char daemon_usage[] =
17 "git-daemon [--verbose] [--syslog] [--export-all]\n"
18 "           [--timeout=n] [--init-timeout=n] [--strict-paths]\n"
19 "           [--base-path=path] [--user-path | --user-path=path]\n"
20 "           [--interpolated-path=path]\n"
21 "           [--reuseaddr] [--detach] [--pid-file=file]\n"
22 "           [--[enable|disable|allow-override|forbid-override]=service]\n"
23 "           [--inetd | [--listen=host_or_ipaddr] [--port=n]\n"
24 "                      [--user=user [--group=group]]\n"
25 "           [directory...]";
27 /* List of acceptable pathname prefixes */
28 static char **ok_paths;
29 static int strict_paths;
31 /* If this is set, git-daemon-export-ok is not required */
32 static int export_all_trees;
34 /* Take all paths relative to this one if non-NULL */
35 static char *base_path;
36 static char *interpolated_path;
38 /* Flag indicating client sent extra args. */
39 static int saw_extended_args;
41 /* If defined, ~user notation is allowed and the string is inserted
42  * after ~user/.  E.g. a request to git://host/~alice/frotz would
43  * go to /home/alice/pub_git/frotz with --user-path=pub_git.
44  */
45 static const char *user_path;
47 /* Timeout, and initial timeout */
48 static unsigned int timeout;
49 static unsigned int init_timeout;
51 /*
52  * Static table for now.  Ugh.
53  * Feel free to make dynamic as needed.
54  */
55 #define INTERP_SLOT_HOST        (0)
56 #define INTERP_SLOT_CANON_HOST  (1)
57 #define INTERP_SLOT_IP          (2)
58 #define INTERP_SLOT_PORT        (3)
59 #define INTERP_SLOT_DIR         (4)
60 #define INTERP_SLOT_PERCENT     (5)
62 static struct interp interp_table[] = {
63         { "%H", 0},
64         { "%CH", 0},
65         { "%IP", 0},
66         { "%P", 0},
67         { "%D", 0},
68         { "%%", 0},
69 };
72 static void logreport(int priority, const char *err, va_list params)
73 {
74         /* We should do a single write so that it is atomic and output
75          * of several processes do not get intermingled. */
76         char buf[1024];
77         int buflen;
78         int maxlen, msglen;
80         /* sizeof(buf) should be big enough for "[pid] \n" */
81         buflen = snprintf(buf, sizeof(buf), "[%ld] ", (long) getpid());
83         maxlen = sizeof(buf) - buflen - 1; /* -1 for our own LF */
84         msglen = vsnprintf(buf + buflen, maxlen, err, params);
86         if (log_syslog) {
87                 syslog(priority, "%s", buf);
88                 return;
89         }
91         /* maxlen counted our own LF but also counts space given to
92          * vsnprintf for the terminating NUL.  We want to make sure that
93          * we have space for our own LF and NUL after the "meat" of the
94          * message, so truncate it at maxlen - 1.
95          */
96         if (msglen > maxlen - 1)
97                 msglen = maxlen - 1;
98         else if (msglen < 0)
99                 msglen = 0; /* Protect against weird return values. */
100         buflen += msglen;
102         buf[buflen++] = '\n';
103         buf[buflen] = '\0';
105         write_in_full(2, buf, buflen);
108 static void logerror(const char *err, ...)
110         va_list params;
111         va_start(params, err);
112         logreport(LOG_ERR, err, params);
113         va_end(params);
116 static void loginfo(const char *err, ...)
118         va_list params;
119         if (!verbose)
120                 return;
121         va_start(params, err);
122         logreport(LOG_INFO, err, params);
123         va_end(params);
126 static void NORETURN daemon_die(const char *err, va_list params)
128         logreport(LOG_ERR, err, params);
129         exit(1);
132 static int avoid_alias(char *p)
134         int sl, ndot;
136         /* 
137          * This resurrects the belts and suspenders paranoia check by HPA
138          * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
139          * does not do getcwd() based path canonicalizations.
140          *
141          * sl becomes true immediately after seeing '/' and continues to
142          * be true as long as dots continue after that without intervening
143          * non-dot character.
144          */
145         if (!p || (*p != '/' && *p != '~'))
146                 return -1;
147         sl = 1; ndot = 0;
148         p++;
150         while (1) {
151                 char ch = *p++;
152                 if (sl) {
153                         if (ch == '.')
154                                 ndot++;
155                         else if (ch == '/') {
156                                 if (ndot < 3)
157                                         /* reject //, /./ and /../ */
158                                         return -1;
159                                 ndot = 0;
160                         }
161                         else if (ch == 0) {
162                                 if (0 < ndot && ndot < 3)
163                                         /* reject /.$ and /..$ */
164                                         return -1;
165                                 return 0;
166                         }
167                         else
168                                 sl = ndot = 0;
169                 }
170                 else if (ch == 0)
171                         return 0;
172                 else if (ch == '/') {
173                         sl = 1;
174                         ndot = 0;
175                 }
176         }
179 static char *path_ok(struct interp *itable)
181         static char rpath[PATH_MAX];
182         static char interp_path[PATH_MAX];
183         char *path;
184         char *dir;
186         dir = itable[INTERP_SLOT_DIR].value;
188         if (avoid_alias(dir)) {
189                 logerror("'%s': aliased", dir);
190                 return NULL;
191         }
193         if (*dir == '~') {
194                 if (!user_path) {
195                         logerror("'%s': User-path not allowed", dir);
196                         return NULL;
197                 }
198                 if (*user_path) {
199                         /* Got either "~alice" or "~alice/foo";
200                          * rewrite them to "~alice/%s" or
201                          * "~alice/%s/foo".
202                          */
203                         int namlen, restlen = strlen(dir);
204                         char *slash = strchr(dir, '/');
205                         if (!slash)
206                                 slash = dir + restlen;
207                         namlen = slash - dir;
208                         restlen -= namlen;
209                         loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
210                         snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
211                                  namlen, dir, user_path, restlen, slash);
212                         dir = rpath;
213                 }
214         }
215         else if (interpolated_path && saw_extended_args) {
216                 if (*dir != '/') {
217                         /* Allow only absolute */
218                         logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
219                         return NULL;
220                 }
222                 interpolate(interp_path, PATH_MAX, interpolated_path,
223                             interp_table, ARRAY_SIZE(interp_table));
224                 loginfo("Interpolated dir '%s'", interp_path);
226                 dir = interp_path;
227         }
228         else if (base_path) {
229                 if (*dir != '/') {
230                         /* Allow only absolute */
231                         logerror("'%s': Non-absolute path denied (base-path active)", dir);
232                         return NULL;
233                 }
234                 snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
235                 dir = rpath;
236         }
238         path = enter_repo(dir, strict_paths);
240         if (!path) {
241                 logerror("'%s': unable to chdir or not a git archive", dir);
242                 return NULL;
243         }
245         if ( ok_paths && *ok_paths ) {
246                 char **pp;
247                 int pathlen = strlen(path);
249                 /* The validation is done on the paths after enter_repo
250                  * appends optional {.git,.git/.git} and friends, but 
251                  * it does not use getcwd().  So if your /pub is
252                  * a symlink to /mnt/pub, you can whitelist /pub and
253                  * do not have to say /mnt/pub.
254                  * Do not say /pub/.
255                  */
256                 for ( pp = ok_paths ; *pp ; pp++ ) {
257                         int len = strlen(*pp);
258                         if (len <= pathlen &&
259                             !memcmp(*pp, path, len) &&
260                             (path[len] == '\0' ||
261                              (!strict_paths && path[len] == '/')))
262                                 return path;
263                 }
264         }
265         else {
266                 /* be backwards compatible */
267                 if (!strict_paths)
268                         return path;
269         }
271         logerror("'%s': not in whitelist", path);
272         return NULL;            /* Fallthrough. Deny by default */
275 typedef int (*daemon_service_fn)(void);
276 struct daemon_service {
277         const char *name;
278         const char *config_name;
279         daemon_service_fn fn;
280         int enabled;
281         int overridable;
282 };
284 static struct daemon_service *service_looking_at;
285 static int service_enabled;
287 static int git_daemon_config(const char *var, const char *value)
289         if (!prefixcmp(var, "daemon.") &&
290             !strcmp(var + 7, service_looking_at->config_name)) {
291                 service_enabled = git_config_bool(var, value);
292                 return 0;
293         }
295         /* we are not interested in parsing any other configuration here */
296         return 0;
299 static int run_service(struct interp *itable, struct daemon_service *service)
301         const char *path;
302         int enabled = service->enabled;
304         loginfo("Request %s for '%s'",
305                 service->name,
306                 itable[INTERP_SLOT_DIR].value);
308         if (!enabled && !service->overridable) {
309                 logerror("'%s': service not enabled.", service->name);
310                 errno = EACCES;
311                 return -1;
312         }
314         if (!(path = path_ok(itable)))
315                 return -1;
317         /*
318          * Security on the cheap.
319          *
320          * We want a readable HEAD, usable "objects" directory, and
321          * a "git-daemon-export-ok" flag that says that the other side
322          * is ok with us doing this.
323          *
324          * path_ok() uses enter_repo() and does whitelist checking.
325          * We only need to make sure the repository is exported.
326          */
328         if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
329                 logerror("'%s': repository not exported.", path);
330                 errno = EACCES;
331                 return -1;
332         }
334         if (service->overridable) {
335                 service_looking_at = service;
336                 service_enabled = -1;
337                 git_config(git_daemon_config);
338                 if (0 <= service_enabled)
339                         enabled = service_enabled;
340         }
341         if (!enabled) {
342                 logerror("'%s': service not enabled for '%s'",
343                          service->name, path);
344                 errno = EACCES;
345                 return -1;
346         }
348         /*
349          * We'll ignore SIGTERM from now on, we have a
350          * good client.
351          */
352         signal(SIGTERM, SIG_IGN);
354         return service->fn();
357 static int upload_pack(void)
359         /* Timeout as string */
360         char timeout_buf[64];
362         snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
364         /* git-upload-pack only ever reads stuff, so this is safe */
365         execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL);
366         return -1;
369 static int upload_archive(void)
371         execl_git_cmd("upload-archive", ".", NULL);
372         return -1;
375 static int receive_pack(void)
377         execl_git_cmd("receive-pack", ".", NULL);
378         return -1;
381 static struct daemon_service daemon_service[] = {
382         { "upload-archive", "uploadarch", upload_archive, 0, 1 },
383         { "upload-pack", "uploadpack", upload_pack, 1, 1 },
384         { "receive-pack", "receivepack", receive_pack, 0, 1 },
385 };
387 static void enable_service(const char *name, int ena) {
388         int i;
389         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
390                 if (!strcmp(daemon_service[i].name, name)) {
391                         daemon_service[i].enabled = ena;
392                         return;
393                 }
394         }
395         die("No such service %s", name);
398 static void make_service_overridable(const char *name, int ena) {
399         int i;
400         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
401                 if (!strcmp(daemon_service[i].name, name)) {
402                         daemon_service[i].overridable = ena;
403                         return;
404                 }
405         }
406         die("No such service %s", name);
409 /*
410  * Separate the "extra args" information as supplied by the client connection.
411  * Any resulting data is squirreled away in the given interpolation table.
412  */
413 static void parse_extra_args(struct interp *table, char *extra_args, int buflen)
415         char *val;
416         int vallen;
417         char *end = extra_args + buflen;
419         while (extra_args < end && *extra_args) {
420                 saw_extended_args = 1;
421                 if (strncasecmp("host=", extra_args, 5) == 0) {
422                         val = extra_args + 5;
423                         vallen = strlen(val) + 1;
424                         if (*val) {
425                                 /* Split <host>:<port> at colon. */
426                                 char *host = val;
427                                 char *port = strrchr(host, ':');
428                                 if (port) {
429                                         *port = 0;
430                                         port++;
431                                         interp_set_entry(table, INTERP_SLOT_PORT, port);
432                                 }
433                                 interp_set_entry(table, INTERP_SLOT_HOST, host);
434                         }
436                         /* On to the next one */
437                         extra_args = val + vallen;
438                 }
439         }
442 void fill_in_extra_table_entries(struct interp *itable)
444         char *hp;
446         /*
447          * Replace literal host with lowercase-ized hostname.
448          */
449         hp = interp_table[INTERP_SLOT_HOST].value;
450         if (!hp)
451                 return;
452         for ( ; *hp; hp++)
453                 *hp = tolower(*hp);
455         /*
456          * Locate canonical hostname and its IP address.
457          */
458 #ifndef NO_IPV6
459         {
460                 struct addrinfo hints;
461                 struct addrinfo *ai, *ai0;
462                 int gai;
463                 static char addrbuf[HOST_NAME_MAX + 1];
465                 memset(&hints, 0, sizeof(hints));
466                 hints.ai_flags = AI_CANONNAME;
468                 gai = getaddrinfo(interp_table[INTERP_SLOT_HOST].value, 0, &hints, &ai0);
469                 if (!gai) {
470                         for (ai = ai0; ai; ai = ai->ai_next) {
471                                 struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
473                                 inet_ntop(AF_INET, &sin_addr->sin_addr,
474                                           addrbuf, sizeof(addrbuf));
475                                 interp_set_entry(interp_table,
476                                                  INTERP_SLOT_CANON_HOST, ai->ai_canonname);
477                                 interp_set_entry(interp_table,
478                                                  INTERP_SLOT_IP, addrbuf);
479                                 break;
480                         }
481                         freeaddrinfo(ai0);
482                 }
483         }
484 #else
485         {
486                 struct hostent *hent;
487                 struct sockaddr_in sa;
488                 char **ap;
489                 static char addrbuf[HOST_NAME_MAX + 1];
491                 hent = gethostbyname(interp_table[INTERP_SLOT_HOST].value);
493                 ap = hent->h_addr_list;
494                 memset(&sa, 0, sizeof sa);
495                 sa.sin_family = hent->h_addrtype;
496                 sa.sin_port = htons(0);
497                 memcpy(&sa.sin_addr, *ap, hent->h_length);
499                 inet_ntop(hent->h_addrtype, &sa.sin_addr,
500                           addrbuf, sizeof(addrbuf));
502                 interp_set_entry(interp_table, INTERP_SLOT_CANON_HOST, hent->h_name);
503                 interp_set_entry(interp_table, INTERP_SLOT_IP, addrbuf);
504         }
505 #endif
509 static int execute(struct sockaddr *addr)
511         static char line[1000];
512         int pktlen, len, i;
514         if (addr) {
515                 char addrbuf[256] = "";
516                 int port = -1;
518                 if (addr->sa_family == AF_INET) {
519                         struct sockaddr_in *sin_addr = (void *) addr;
520                         inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
521                         port = sin_addr->sin_port;
522 #ifndef NO_IPV6
523                 } else if (addr && addr->sa_family == AF_INET6) {
524                         struct sockaddr_in6 *sin6_addr = (void *) addr;
526                         char *buf = addrbuf;
527                         *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
528                         inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
529                         strcat(buf, "]");
531                         port = sin6_addr->sin6_port;
532 #endif
533                 }
534                 loginfo("Connection from %s:%d", addrbuf, port);
535         }
537         alarm(init_timeout ? init_timeout : timeout);
538         pktlen = packet_read_line(0, line, sizeof(line));
539         alarm(0);
541         len = strlen(line);
542         if (pktlen != len)
543                 loginfo("Extended attributes (%d bytes) exist <%.*s>",
544                         (int) pktlen - len,
545                         (int) pktlen - len, line + len + 1);
546         if (len && line[len-1] == '\n') {
547                 line[--len] = 0;
548                 pktlen--;
549         }
551         /*
552          * Initialize the path interpolation table for this connection.
553          */
554         interp_clear_table(interp_table, ARRAY_SIZE(interp_table));
555         interp_set_entry(interp_table, INTERP_SLOT_PERCENT, "%");
557         if (len != pktlen) {
558             parse_extra_args(interp_table, line + len + 1, pktlen - len - 1);
559             fill_in_extra_table_entries(interp_table);
560         }
562         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
563                 struct daemon_service *s = &(daemon_service[i]);
564                 int namelen = strlen(s->name);
565                 if (!prefixcmp(line, "git-") &&
566                     !strncmp(s->name, line + 4, namelen) &&
567                     line[namelen + 4] == ' ') {
568                         /*
569                          * Note: The directory here is probably context sensitive,
570                          * and might depend on the actual service being performed.
571                          */
572                         interp_set_entry(interp_table,
573                                          INTERP_SLOT_DIR, line + namelen + 5);
574                         return run_service(interp_table, s);
575                 }
576         }
578         logerror("Protocol error: '%s'", line);
579         return -1;
583 /*
584  * We count spawned/reaped separately, just to avoid any
585  * races when updating them from signals. The SIGCHLD handler
586  * will only update children_reaped, and the fork logic will
587  * only update children_spawned.
588  *
589  * MAX_CHILDREN should be a power-of-two to make the modulus
590  * operation cheap. It should also be at least twice
591  * the maximum number of connections we will ever allow.
592  */
593 #define MAX_CHILDREN 128
595 static int max_connections = 25;
597 /* These are updated by the signal handler */
598 static volatile unsigned int children_reaped;
599 static pid_t dead_child[MAX_CHILDREN];
601 /* These are updated by the main loop */
602 static unsigned int children_spawned;
603 static unsigned int children_deleted;
605 static struct child {
606         pid_t pid;
607         int addrlen;
608         struct sockaddr_storage address;
609 } live_child[MAX_CHILDREN];
611 static void add_child(int idx, pid_t pid, struct sockaddr *addr, int addrlen)
613         live_child[idx].pid = pid;
614         live_child[idx].addrlen = addrlen;
615         memcpy(&live_child[idx].address, addr, addrlen);
618 /*
619  * Walk from "deleted" to "spawned", and remove child "pid".
620  *
621  * We move everything up by one, since the new "deleted" will
622  * be one higher.
623  */
624 static void remove_child(pid_t pid, unsigned deleted, unsigned spawned)
626         struct child n;
628         deleted %= MAX_CHILDREN;
629         spawned %= MAX_CHILDREN;
630         if (live_child[deleted].pid == pid) {
631                 live_child[deleted].pid = -1;
632                 return;
633         }
634         n = live_child[deleted];
635         for (;;) {
636                 struct child m;
637                 deleted = (deleted + 1) % MAX_CHILDREN;
638                 if (deleted == spawned)
639                         die("could not find dead child %d\n", pid);
640                 m = live_child[deleted];
641                 live_child[deleted] = n;
642                 if (m.pid == pid)
643                         return;
644                 n = m;
645         }
648 /*
649  * This gets called if the number of connections grows
650  * past "max_connections".
651  *
652  * We _should_ start off by searching for connections
653  * from the same IP, and if there is some address wth
654  * multiple connections, we should kill that first.
655  *
656  * As it is, we just "randomly" kill 25% of the connections,
657  * and our pseudo-random generator sucks too. I have no
658  * shame.
659  *
660  * Really, this is just a place-holder for a _real_ algorithm.
661  */
662 static void kill_some_children(int signo, unsigned start, unsigned stop)
664         start %= MAX_CHILDREN;
665         stop %= MAX_CHILDREN;
666         while (start != stop) {
667                 if (!(start & 3))
668                         kill(live_child[start].pid, signo);
669                 start = (start + 1) % MAX_CHILDREN;
670         }
673 static void check_max_connections(void)
675         for (;;) {
676                 int active;
677                 unsigned spawned, reaped, deleted;
679                 spawned = children_spawned;
680                 reaped = children_reaped;
681                 deleted = children_deleted;
683                 while (deleted < reaped) {
684                         pid_t pid = dead_child[deleted % MAX_CHILDREN];
685                         remove_child(pid, deleted, spawned);
686                         deleted++;
687                 }
688                 children_deleted = deleted;
690                 active = spawned - deleted;
691                 if (active <= max_connections)
692                         break;
694                 /* Kill some unstarted connections with SIGTERM */
695                 kill_some_children(SIGTERM, deleted, spawned);
696                 if (active <= max_connections << 1)
697                         break;
699                 /* If the SIGTERM thing isn't helping use SIGKILL */
700                 kill_some_children(SIGKILL, deleted, spawned);
701                 sleep(1);
702         }
705 static void handle(int incoming, struct sockaddr *addr, int addrlen)
707         pid_t pid = fork();
709         if (pid) {
710                 unsigned idx;
712                 close(incoming);
713                 if (pid < 0)
714                         return;
716                 idx = children_spawned % MAX_CHILDREN;
717                 children_spawned++;
718                 add_child(idx, pid, addr, addrlen);
720                 check_max_connections();
721                 return;
722         }
724         dup2(incoming, 0);
725         dup2(incoming, 1);
726         close(incoming);
728         exit(execute(addr));
731 static void child_handler(int signo)
733         for (;;) {
734                 int status;
735                 pid_t pid = waitpid(-1, &status, WNOHANG);
737                 if (pid > 0) {
738                         unsigned reaped = children_reaped;
739                         dead_child[reaped % MAX_CHILDREN] = pid;
740                         children_reaped = reaped + 1;
741                         /* XXX: Custom logging, since we don't wanna getpid() */
742                         if (verbose) {
743                                 const char *dead = "";
744                                 if (!WIFEXITED(status) || WEXITSTATUS(status) > 0)
745                                         dead = " (with error)";
746                                 if (log_syslog)
747                                         syslog(LOG_INFO, "[%d] Disconnected%s", pid, dead);
748                                 else
749                                         fprintf(stderr, "[%d] Disconnected%s\n", pid, dead);
750                         }
751                         continue;
752                 }
753                 break;
754         }
757 static int set_reuse_addr(int sockfd)
759         int on = 1;
761         if (!reuseaddr)
762                 return 0;
763         return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
764                           &on, sizeof(on));
767 #ifndef NO_IPV6
769 static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
771         int socknum = 0, *socklist = NULL;
772         int maxfd = -1;
773         char pbuf[NI_MAXSERV];
774         struct addrinfo hints, *ai0, *ai;
775         int gai;
776         long flags;
778         sprintf(pbuf, "%d", listen_port);
779         memset(&hints, 0, sizeof(hints));
780         hints.ai_family = AF_UNSPEC;
781         hints.ai_socktype = SOCK_STREAM;
782         hints.ai_protocol = IPPROTO_TCP;
783         hints.ai_flags = AI_PASSIVE;
785         gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
786         if (gai)
787                 die("getaddrinfo() failed: %s\n", gai_strerror(gai));
789         for (ai = ai0; ai; ai = ai->ai_next) {
790                 int sockfd;
792                 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
793                 if (sockfd < 0)
794                         continue;
795                 if (sockfd >= FD_SETSIZE) {
796                         error("too large socket descriptor.");
797                         close(sockfd);
798                         continue;
799                 }
801 #ifdef IPV6_V6ONLY
802                 if (ai->ai_family == AF_INET6) {
803                         int on = 1;
804                         setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
805                                    &on, sizeof(on));
806                         /* Note: error is not fatal */
807                 }
808 #endif
810                 if (set_reuse_addr(sockfd)) {
811                         close(sockfd);
812                         continue;
813                 }
815                 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
816                         close(sockfd);
817                         continue;       /* not fatal */
818                 }
819                 if (listen(sockfd, 5) < 0) {
820                         close(sockfd);
821                         continue;       /* not fatal */
822                 }
824                 flags = fcntl(sockfd, F_GETFD, 0);
825                 if (flags >= 0)
826                         fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
828                 socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
829                 socklist[socknum++] = sockfd;
831                 if (maxfd < sockfd)
832                         maxfd = sockfd;
833         }
835         freeaddrinfo(ai0);
837         *socklist_p = socklist;
838         return socknum;
841 #else /* NO_IPV6 */
843 static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
845         struct sockaddr_in sin;
846         int sockfd;
847         long flags;
849         memset(&sin, 0, sizeof sin);
850         sin.sin_family = AF_INET;
851         sin.sin_port = htons(listen_port);
853         if (listen_addr) {
854                 /* Well, host better be an IP address here. */
855                 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
856                         return 0;
857         } else {
858                 sin.sin_addr.s_addr = htonl(INADDR_ANY);
859         }
861         sockfd = socket(AF_INET, SOCK_STREAM, 0);
862         if (sockfd < 0)
863                 return 0;
865         if (set_reuse_addr(sockfd)) {
866                 close(sockfd);
867                 return 0;
868         }
870         if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
871                 close(sockfd);
872                 return 0;
873         }
875         if (listen(sockfd, 5) < 0) {
876                 close(sockfd);
877                 return 0;
878         }
880         flags = fcntl(sockfd, F_GETFD, 0);
881         if (flags >= 0)
882                 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
884         *socklist_p = xmalloc(sizeof(int));
885         **socklist_p = sockfd;
886         return 1;
889 #endif
891 static int service_loop(int socknum, int *socklist)
893         struct pollfd *pfd;
894         int i;
896         pfd = xcalloc(socknum, sizeof(struct pollfd));
898         for (i = 0; i < socknum; i++) {
899                 pfd[i].fd = socklist[i];
900                 pfd[i].events = POLLIN;
901         }
903         signal(SIGCHLD, child_handler);
905         for (;;) {
906                 int i;
908                 if (poll(pfd, socknum, -1) < 0) {
909                         if (errno != EINTR) {
910                                 error("poll failed, resuming: %s",
911                                       strerror(errno));
912                                 sleep(1);
913                         }
914                         continue;
915                 }
917                 for (i = 0; i < socknum; i++) {
918                         if (pfd[i].revents & POLLIN) {
919                                 struct sockaddr_storage ss;
920                                 unsigned int sslen = sizeof(ss);
921                                 int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
922                                 if (incoming < 0) {
923                                         switch (errno) {
924                                         case EAGAIN:
925                                         case EINTR:
926                                         case ECONNABORTED:
927                                                 continue;
928                                         default:
929                                                 die("accept returned %s", strerror(errno));
930                                         }
931                                 }
932                                 handle(incoming, (struct sockaddr *)&ss, sslen);
933                         }
934                 }
935         }
938 /* if any standard file descriptor is missing open it to /dev/null */
939 static void sanitize_stdfds(void)
941         int fd = open("/dev/null", O_RDWR, 0);
942         while (fd != -1 && fd < 2)
943                 fd = dup(fd);
944         if (fd == -1)
945                 die("open /dev/null or dup failed: %s", strerror(errno));
946         if (fd > 2)
947                 close(fd);
950 static void daemonize(void)
952         switch (fork()) {
953                 case 0:
954                         break;
955                 case -1:
956                         die("fork failed: %s", strerror(errno));
957                 default:
958                         exit(0);
959         }
960         if (setsid() == -1)
961                 die("setsid failed: %s", strerror(errno));
962         close(0);
963         close(1);
964         close(2);
965         sanitize_stdfds();
968 static void store_pid(const char *path)
970         FILE *f = fopen(path, "w");
971         if (!f)
972                 die("cannot open pid file %s: %s", path, strerror(errno));
973         fprintf(f, "%d\n", getpid());
974         fclose(f);
977 static int serve(char *listen_addr, int listen_port, struct passwd *pass, gid_t gid)
979         int socknum, *socklist;
981         socknum = socksetup(listen_addr, listen_port, &socklist);
982         if (socknum == 0)
983                 die("unable to allocate any listen sockets on host %s port %u",
984                     listen_addr, listen_port);
986         if (pass && gid &&
987             (initgroups(pass->pw_name, gid) || setgid (gid) ||
988              setuid(pass->pw_uid)))
989                 die("cannot drop privileges");
991         return service_loop(socknum, socklist);
994 int main(int argc, char **argv)
996         int listen_port = 0;
997         char *listen_addr = NULL;
998         int inetd_mode = 0;
999         const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1000         int detach = 0;
1001         struct passwd *pass = NULL;
1002         struct group *group;
1003         gid_t gid = 0;
1004         int i;
1006         /* Without this we cannot rely on waitpid() to tell
1007          * what happened to our children.
1008          */
1009         signal(SIGCHLD, SIG_DFL);
1011         for (i = 1; i < argc; i++) {
1012                 char *arg = argv[i];
1014                 if (!prefixcmp(arg, "--listen=")) {
1015                     char *p = arg + 9;
1016                     char *ph = listen_addr = xmalloc(strlen(arg + 9) + 1);
1017                     while (*p)
1018                         *ph++ = tolower(*p++);
1019                     *ph = 0;
1020                     continue;
1021                 }
1022                 if (!prefixcmp(arg, "--port=")) {
1023                         char *end;
1024                         unsigned long n;
1025                         n = strtoul(arg+7, &end, 0);
1026                         if (arg[7] && !*end) {
1027                                 listen_port = n;
1028                                 continue;
1029                         }
1030                 }
1031                 if (!strcmp(arg, "--inetd")) {
1032                         inetd_mode = 1;
1033                         log_syslog = 1;
1034                         continue;
1035                 }
1036                 if (!strcmp(arg, "--verbose")) {
1037                         verbose = 1;
1038                         continue;
1039                 }
1040                 if (!strcmp(arg, "--syslog")) {
1041                         log_syslog = 1;
1042                         continue;
1043                 }
1044                 if (!strcmp(arg, "--export-all")) {
1045                         export_all_trees = 1;
1046                         continue;
1047                 }
1048                 if (!prefixcmp(arg, "--timeout=")) {
1049                         timeout = atoi(arg+10);
1050                         continue;
1051                 }
1052                 if (!prefixcmp(arg, "--init-timeout=")) {
1053                         init_timeout = atoi(arg+15);
1054                         continue;
1055                 }
1056                 if (!strcmp(arg, "--strict-paths")) {
1057                         strict_paths = 1;
1058                         continue;
1059                 }
1060                 if (!prefixcmp(arg, "--base-path=")) {
1061                         base_path = arg+12;
1062                         continue;
1063                 }
1064                 if (!prefixcmp(arg, "--interpolated-path=")) {
1065                         interpolated_path = arg+20;
1066                         continue;
1067                 }
1068                 if (!strcmp(arg, "--reuseaddr")) {
1069                         reuseaddr = 1;
1070                         continue;
1071                 }
1072                 if (!strcmp(arg, "--user-path")) {
1073                         user_path = "";
1074                         continue;
1075                 }
1076                 if (!prefixcmp(arg, "--user-path=")) {
1077                         user_path = arg + 12;
1078                         continue;
1079                 }
1080                 if (!prefixcmp(arg, "--pid-file=")) {
1081                         pid_file = arg + 11;
1082                         continue;
1083                 }
1084                 if (!strcmp(arg, "--detach")) {
1085                         detach = 1;
1086                         log_syslog = 1;
1087                         continue;
1088                 }
1089                 if (!prefixcmp(arg, "--user=")) {
1090                         user_name = arg + 7;
1091                         continue;
1092                 }
1093                 if (!prefixcmp(arg, "--group=")) {
1094                         group_name = arg + 8;
1095                         continue;
1096                 }
1097                 if (!prefixcmp(arg, "--enable=")) {
1098                         enable_service(arg + 9, 1);
1099                         continue;
1100                 }
1101                 if (!prefixcmp(arg, "--disable=")) {
1102                         enable_service(arg + 10, 0);
1103                         continue;
1104                 }
1105                 if (!prefixcmp(arg, "--allow-override=")) {
1106                         make_service_overridable(arg + 17, 1);
1107                         continue;
1108                 }
1109                 if (!prefixcmp(arg, "--forbid-override=")) {
1110                         make_service_overridable(arg + 18, 0);
1111                         continue;
1112                 }
1113                 if (!strcmp(arg, "--")) {
1114                         ok_paths = &argv[i+1];
1115                         break;
1116                 } else if (arg[0] != '-') {
1117                         ok_paths = &argv[i];
1118                         break;
1119                 }
1121                 usage(daemon_usage);
1122         }
1124         if (inetd_mode && (group_name || user_name))
1125                 die("--user and --group are incompatible with --inetd");
1127         if (inetd_mode && (listen_port || listen_addr))
1128                 die("--listen= and --port= are incompatible with --inetd");
1129         else if (listen_port == 0)
1130                 listen_port = DEFAULT_GIT_PORT;
1132         if (group_name && !user_name)
1133                 die("--group supplied without --user");
1135         if (user_name) {
1136                 pass = getpwnam(user_name);
1137                 if (!pass)
1138                         die("user not found - %s", user_name);
1140                 if (!group_name)
1141                         gid = pass->pw_gid;
1142                 else {
1143                         group = getgrnam(group_name);
1144                         if (!group)
1145                                 die("group not found - %s", group_name);
1147                         gid = group->gr_gid;
1148                 }
1149         }
1151         if (log_syslog) {
1152                 openlog("git-daemon", 0, LOG_DAEMON);
1153                 set_die_routine(daemon_die);
1154         }
1156         if (strict_paths && (!ok_paths || !*ok_paths))
1157                 die("option --strict-paths requires a whitelist");
1159         if (inetd_mode) {
1160                 struct sockaddr_storage ss;
1161                 struct sockaddr *peer = (struct sockaddr *)&ss;
1162                 socklen_t slen = sizeof(ss);
1164                 freopen("/dev/null", "w", stderr);
1166                 if (getpeername(0, peer, &slen))
1167                         peer = NULL;
1169                 return execute(peer);
1170         }
1172         if (detach)
1173                 daemonize();
1174         else
1175                 sanitize_stdfds();
1177         if (pid_file)
1178                 store_pid(pid_file);
1180         return serve(listen_addr, listen_port, pass, gid);