4 #include "interpolate.h"
9 #define HOST_NAME_MAX 256
16 static int log_syslog;
20 static const char daemon_usage[] =
21 "git daemon [--verbose] [--syslog] [--export-all]\n"
22 " [--timeout=n] [--init-timeout=n] [--max-connections=n]\n"
23 " [--strict-paths] [--base-path=path] [--base-path-relaxed]\n"
24 " [--user-path | --user-path=path]\n"
25 " [--interpolated-path=path]\n"
26 " [--reuseaddr] [--detach] [--pid-file=file]\n"
27 " [--[enable|disable|allow-override|forbid-override]=service]\n"
28 " [--inetd | [--listen=host_or_ipaddr] [--port=n]\n"
29 " [--user=user [--group=group]]\n"
32 /* List of acceptable pathname prefixes */
33 static char **ok_paths;
34 static int strict_paths;
36 /* If this is set, git-daemon-export-ok is not required */
37 static int export_all_trees;
39 /* Take all paths relative to this one if non-NULL */
40 static char *base_path;
41 static char *interpolated_path;
42 static int base_path_relaxed;
44 /* Flag indicating client sent extra args. */
45 static int saw_extended_args;
47 /* If defined, ~user notation is allowed and the string is inserted
48 * after ~user/. E.g. a request to git://host/~alice/frotz would
49 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
51 static const char *user_path;
53 /* Timeout, and initial timeout */
54 static unsigned int timeout;
55 static unsigned int init_timeout;
58 * Static table for now. Ugh.
59 * Feel free to make dynamic as needed.
61 #define INTERP_SLOT_HOST (0)
62 #define INTERP_SLOT_CANON_HOST (1)
63 #define INTERP_SLOT_IP (2)
64 #define INTERP_SLOT_PORT (3)
65 #define INTERP_SLOT_DIR (4)
66 #define INTERP_SLOT_PERCENT (5)
68 static struct interp interp_table[] = {
78 static void logreport(int priority, const char *err, va_list params)
82 vsnprintf(buf, sizeof(buf), err, params);
83 syslog(priority, "%s", buf);
86 * Since stderr is set to linebuffered mode, the
87 * logging of different processes will not overlap
89 fprintf(stderr, "[%d] ", (int)getpid());
90 vfprintf(stderr, err, params);
95 static void logerror(const char *err, ...)
98 va_start(params, err);
99 logreport(LOG_ERR, err, params);
103 static void loginfo(const char *err, ...)
108 va_start(params, err);
109 logreport(LOG_INFO, err, params);
113 static void NORETURN daemon_die(const char *err, va_list params)
115 logreport(LOG_ERR, err, params);
119 static int avoid_alias(char *p)
124 * This resurrects the belts and suspenders paranoia check by HPA
125 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
126 * does not do getcwd() based path canonicalizations.
128 * sl becomes true immediately after seeing '/' and continues to
129 * be true as long as dots continue after that without intervening
132 if (!p || (*p != '/' && *p != '~'))
142 else if (ch == '/') {
144 /* reject //, /./ and /../ */
149 if (0 < ndot && ndot < 3)
150 /* reject /.$ and /..$ */
159 else if (ch == '/') {
166 static char *path_ok(struct interp *itable)
168 static char rpath[PATH_MAX];
169 static char interp_path[PATH_MAX];
170 int retried_path = 0;
174 dir = itable[INTERP_SLOT_DIR].value;
176 if (avoid_alias(dir)) {
177 logerror("'%s': aliased", dir);
183 logerror("'%s': User-path not allowed", dir);
187 /* Got either "~alice" or "~alice/foo";
188 * rewrite them to "~alice/%s" or
191 int namlen, restlen = strlen(dir);
192 char *slash = strchr(dir, '/');
194 slash = dir + restlen;
195 namlen = slash - dir;
197 loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
198 snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
199 namlen, dir, user_path, restlen, slash);
203 else if (interpolated_path && saw_extended_args) {
205 /* Allow only absolute */
206 logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
210 interpolate(interp_path, PATH_MAX, interpolated_path,
211 interp_table, ARRAY_SIZE(interp_table));
212 loginfo("Interpolated dir '%s'", interp_path);
216 else if (base_path) {
218 /* Allow only absolute */
219 logerror("'%s': Non-absolute path denied (base-path active)", dir);
222 snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
227 path = enter_repo(dir, strict_paths);
232 * if we fail and base_path_relaxed is enabled, try without
233 * prefixing the base path
235 if (base_path && base_path_relaxed && !retried_path) {
236 dir = itable[INTERP_SLOT_DIR].value;
244 logerror("'%s': unable to chdir or not a git archive", dir);
248 if ( ok_paths && *ok_paths ) {
250 int pathlen = strlen(path);
252 /* The validation is done on the paths after enter_repo
253 * appends optional {.git,.git/.git} and friends, but
254 * it does not use getcwd(). So if your /pub is
255 * a symlink to /mnt/pub, you can whitelist /pub and
256 * do not have to say /mnt/pub.
259 for ( pp = ok_paths ; *pp ; pp++ ) {
260 int len = strlen(*pp);
261 if (len <= pathlen &&
262 !memcmp(*pp, path, len) &&
263 (path[len] == '\0' ||
264 (!strict_paths && path[len] == '/')))
269 /* be backwards compatible */
274 logerror("'%s': not in whitelist", path);
275 return NULL; /* Fallthrough. Deny by default */
278 typedef int (*daemon_service_fn)(void);
279 struct daemon_service {
281 const char *config_name;
282 daemon_service_fn fn;
287 static struct daemon_service *service_looking_at;
288 static int service_enabled;
290 static int git_daemon_config(const char *var, const char *value, void *cb)
292 if (!prefixcmp(var, "daemon.") &&
293 !strcmp(var + 7, service_looking_at->config_name)) {
294 service_enabled = git_config_bool(var, value);
298 /* we are not interested in parsing any other configuration here */
302 static int run_service(struct interp *itable, struct daemon_service *service)
305 int enabled = service->enabled;
307 loginfo("Request %s for '%s'",
309 itable[INTERP_SLOT_DIR].value);
311 if (!enabled && !service->overridable) {
312 logerror("'%s': service not enabled.", service->name);
317 if (!(path = path_ok(itable)))
321 * Security on the cheap.
323 * We want a readable HEAD, usable "objects" directory, and
324 * a "git-daemon-export-ok" flag that says that the other side
325 * is ok with us doing this.
327 * path_ok() uses enter_repo() and does whitelist checking.
328 * We only need to make sure the repository is exported.
331 if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
332 logerror("'%s': repository not exported.", path);
337 if (service->overridable) {
338 service_looking_at = service;
339 service_enabled = -1;
340 git_config(git_daemon_config, NULL);
341 if (0 <= service_enabled)
342 enabled = service_enabled;
345 logerror("'%s': service not enabled for '%s'",
346 service->name, path);
352 * We'll ignore SIGTERM from now on, we have a
355 signal(SIGTERM, SIG_IGN);
357 return service->fn();
360 static int upload_pack(void)
362 /* Timeout as string */
363 char timeout_buf[64];
365 snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
367 /* git-upload-pack only ever reads stuff, so this is safe */
368 execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL);
372 static int upload_archive(void)
374 execl_git_cmd("upload-archive", ".", NULL);
378 static int receive_pack(void)
380 execl_git_cmd("receive-pack", ".", NULL);
384 static struct daemon_service daemon_service[] = {
385 { "upload-archive", "uploadarch", upload_archive, 0, 1 },
386 { "upload-pack", "uploadpack", upload_pack, 1, 1 },
387 { "receive-pack", "receivepack", receive_pack, 0, 1 },
390 static void enable_service(const char *name, int ena)
393 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
394 if (!strcmp(daemon_service[i].name, name)) {
395 daemon_service[i].enabled = ena;
399 die("No such service %s", name);
402 static void make_service_overridable(const char *name, int ena)
405 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
406 if (!strcmp(daemon_service[i].name, name)) {
407 daemon_service[i].overridable = ena;
411 die("No such service %s", name);
415 * Separate the "extra args" information as supplied by the client connection.
416 * Any resulting data is squirreled away in the given interpolation table.
418 static void parse_extra_args(struct interp *table, char *extra_args, int buflen)
422 char *end = extra_args + buflen;
424 while (extra_args < end && *extra_args) {
425 saw_extended_args = 1;
426 if (strncasecmp("host=", extra_args, 5) == 0) {
427 val = extra_args + 5;
428 vallen = strlen(val) + 1;
430 /* Split <host>:<port> at colon. */
432 char *port = strrchr(host, ':');
436 interp_set_entry(table, INTERP_SLOT_PORT, port);
438 interp_set_entry(table, INTERP_SLOT_HOST, host);
441 /* On to the next one */
442 extra_args = val + vallen;
447 static void fill_in_extra_table_entries(struct interp *itable)
452 * Replace literal host with lowercase-ized hostname.
454 hp = interp_table[INTERP_SLOT_HOST].value;
461 * Locate canonical hostname and its IP address.
465 struct addrinfo hints;
466 struct addrinfo *ai, *ai0;
468 static char addrbuf[HOST_NAME_MAX + 1];
470 memset(&hints, 0, sizeof(hints));
471 hints.ai_flags = AI_CANONNAME;
473 gai = getaddrinfo(interp_table[INTERP_SLOT_HOST].value, 0, &hints, &ai0);
475 for (ai = ai0; ai; ai = ai->ai_next) {
476 struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
478 inet_ntop(AF_INET, &sin_addr->sin_addr,
479 addrbuf, sizeof(addrbuf));
480 interp_set_entry(interp_table,
481 INTERP_SLOT_CANON_HOST, ai->ai_canonname);
482 interp_set_entry(interp_table,
483 INTERP_SLOT_IP, addrbuf);
491 struct hostent *hent;
492 struct sockaddr_in sa;
494 static char addrbuf[HOST_NAME_MAX + 1];
496 hent = gethostbyname(interp_table[INTERP_SLOT_HOST].value);
498 ap = hent->h_addr_list;
499 memset(&sa, 0, sizeof sa);
500 sa.sin_family = hent->h_addrtype;
501 sa.sin_port = htons(0);
502 memcpy(&sa.sin_addr, *ap, hent->h_length);
504 inet_ntop(hent->h_addrtype, &sa.sin_addr,
505 addrbuf, sizeof(addrbuf));
507 interp_set_entry(interp_table, INTERP_SLOT_CANON_HOST, hent->h_name);
508 interp_set_entry(interp_table, INTERP_SLOT_IP, addrbuf);
514 static int execute(struct sockaddr *addr)
516 static char line[1000];
520 char addrbuf[256] = "";
523 if (addr->sa_family == AF_INET) {
524 struct sockaddr_in *sin_addr = (void *) addr;
525 inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
526 port = ntohs(sin_addr->sin_port);
528 } else if (addr && addr->sa_family == AF_INET6) {
529 struct sockaddr_in6 *sin6_addr = (void *) addr;
532 *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
533 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
536 port = ntohs(sin6_addr->sin6_port);
539 loginfo("Connection from %s:%d", addrbuf, port);
542 alarm(init_timeout ? init_timeout : timeout);
543 pktlen = packet_read_line(0, line, sizeof(line));
548 loginfo("Extended attributes (%d bytes) exist <%.*s>",
550 (int) pktlen - len, line + len + 1);
551 if (len && line[len-1] == '\n') {
557 * Initialize the path interpolation table for this connection.
559 interp_clear_table(interp_table, ARRAY_SIZE(interp_table));
560 interp_set_entry(interp_table, INTERP_SLOT_PERCENT, "%");
563 parse_extra_args(interp_table, line + len + 1, pktlen - len - 1);
564 fill_in_extra_table_entries(interp_table);
567 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
568 struct daemon_service *s = &(daemon_service[i]);
569 int namelen = strlen(s->name);
570 if (!prefixcmp(line, "git-") &&
571 !strncmp(s->name, line + 4, namelen) &&
572 line[namelen + 4] == ' ') {
574 * Note: The directory here is probably context sensitive,
575 * and might depend on the actual service being performed.
577 interp_set_entry(interp_table,
578 INTERP_SLOT_DIR, line + namelen + 5);
579 return run_service(interp_table, s);
583 logerror("Protocol error: '%s'", line);
587 static int max_connections = 32;
589 static unsigned int live_children;
591 static struct child {
594 struct sockaddr_storage address;
597 static void add_child(pid_t pid, struct sockaddr *addr, int addrlen)
599 struct child *newborn, **cradle;
602 * This must be xcalloc() -- we'll compare the whole sockaddr_storage
603 * but individual address may be shorter.
605 newborn = xcalloc(1, sizeof(*newborn));
608 memcpy(&newborn->address, addr, addrlen);
609 for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
610 if (!memcmp(&(*cradle)->address, &newborn->address,
611 sizeof(newborn->address)))
613 newborn->next = *cradle;
617 static void remove_child(pid_t pid)
619 struct child **cradle, *blanket;
621 for (cradle = &firstborn; (blanket = *cradle); cradle = &blanket->next)
622 if (blanket->pid == pid) {
623 *cradle = blanket->next;
631 * This gets called if the number of connections grows
632 * past "max_connections".
634 * We kill the newest connection from a duplicate IP.
636 static void kill_some_child(void)
638 const struct child *blanket, *next;
640 if (!(blanket = firstborn))
643 for (; (next = blanket->next); blanket = next)
644 if (!memcmp(&blanket->address, &next->address,
645 sizeof(next->address))) {
646 kill(blanket->pid, SIGTERM);
651 static void check_dead_children(void)
656 while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
657 const char *dead = "";
659 if (!WIFEXITED(status) || (WEXITSTATUS(status) > 0))
660 dead = " (with error)";
661 loginfo("[%d] Disconnected%s", (int)pid, dead);
665 static void handle(int incoming, struct sockaddr *addr, int addrlen)
669 if (max_connections && live_children >= max_connections) {
671 sleep(1); /* give it some time to die */
672 check_dead_children();
673 if (live_children >= max_connections) {
675 logerror("Too many children, dropping connection");
680 if ((pid = fork())) {
683 logerror("Couldn't fork %s", strerror(errno));
687 add_child(pid, addr, addrlen);
698 static void child_handler(int signo)
701 * Otherwise empty handler because systemcalls will get interrupted
702 * upon signal receipt
703 * SysV needs the handler to be rearmed
705 signal(SIGCHLD, child_handler);
708 static int set_reuse_addr(int sockfd)
714 return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
720 static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
722 int socknum = 0, *socklist = NULL;
724 char pbuf[NI_MAXSERV];
725 struct addrinfo hints, *ai0, *ai;
729 sprintf(pbuf, "%d", listen_port);
730 memset(&hints, 0, sizeof(hints));
731 hints.ai_family = AF_UNSPEC;
732 hints.ai_socktype = SOCK_STREAM;
733 hints.ai_protocol = IPPROTO_TCP;
734 hints.ai_flags = AI_PASSIVE;
736 gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
738 die("getaddrinfo() failed: %s\n", gai_strerror(gai));
740 for (ai = ai0; ai; ai = ai->ai_next) {
743 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
746 if (sockfd >= FD_SETSIZE) {
747 logerror("Socket descriptor too large");
753 if (ai->ai_family == AF_INET6) {
755 setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
757 /* Note: error is not fatal */
761 if (set_reuse_addr(sockfd)) {
766 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
768 continue; /* not fatal */
770 if (listen(sockfd, 5) < 0) {
772 continue; /* not fatal */
775 flags = fcntl(sockfd, F_GETFD, 0);
777 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
779 socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
780 socklist[socknum++] = sockfd;
788 *socklist_p = socklist;
794 static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
796 struct sockaddr_in sin;
800 memset(&sin, 0, sizeof sin);
801 sin.sin_family = AF_INET;
802 sin.sin_port = htons(listen_port);
805 /* Well, host better be an IP address here. */
806 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
809 sin.sin_addr.s_addr = htonl(INADDR_ANY);
812 sockfd = socket(AF_INET, SOCK_STREAM, 0);
816 if (set_reuse_addr(sockfd)) {
821 if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
826 if (listen(sockfd, 5) < 0) {
831 flags = fcntl(sockfd, F_GETFD, 0);
833 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
835 *socklist_p = xmalloc(sizeof(int));
836 **socklist_p = sockfd;
842 static int service_loop(int socknum, int *socklist)
847 pfd = xcalloc(socknum, sizeof(struct pollfd));
849 for (i = 0; i < socknum; i++) {
850 pfd[i].fd = socklist[i];
851 pfd[i].events = POLLIN;
854 signal(SIGCHLD, child_handler);
859 check_dead_children();
861 if (poll(pfd, socknum, -1) < 0) {
862 if (errno != EINTR) {
863 logerror("Poll failed, resuming: %s",
870 for (i = 0; i < socknum; i++) {
871 if (pfd[i].revents & POLLIN) {
872 struct sockaddr_storage ss;
873 unsigned int sslen = sizeof(ss);
874 int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
882 die("accept returned %s", strerror(errno));
885 handle(incoming, (struct sockaddr *)&ss, sslen);
891 /* if any standard file descriptor is missing open it to /dev/null */
892 static void sanitize_stdfds(void)
894 int fd = open("/dev/null", O_RDWR, 0);
895 while (fd != -1 && fd < 2)
898 die("open /dev/null or dup failed: %s", strerror(errno));
903 static void daemonize(void)
909 die("fork failed: %s", strerror(errno));
914 die("setsid failed: %s", strerror(errno));
921 static void store_pid(const char *path)
923 FILE *f = fopen(path, "w");
925 die("cannot open pid file %s: %s", path, strerror(errno));
926 if (fprintf(f, "%d\n", getpid()) < 0 || fclose(f) != 0)
927 die("failed to write pid file %s: %s", path, strerror(errno));
930 static int serve(char *listen_addr, int listen_port, struct passwd *pass, gid_t gid)
932 int socknum, *socklist;
934 socknum = socksetup(listen_addr, listen_port, &socklist);
936 die("unable to allocate any listen sockets on host %s port %u",
937 listen_addr, listen_port);
940 (initgroups(pass->pw_name, gid) || setgid (gid) ||
941 setuid(pass->pw_uid)))
942 die("cannot drop privileges");
944 return service_loop(socknum, socklist);
947 int main(int argc, char **argv)
950 char *listen_addr = NULL;
952 const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
954 struct passwd *pass = NULL;
959 for (i = 1; i < argc; i++) {
962 if (!prefixcmp(arg, "--listen=")) {
964 char *ph = listen_addr = xmalloc(strlen(arg + 9) + 1);
966 *ph++ = tolower(*p++);
970 if (!prefixcmp(arg, "--port=")) {
973 n = strtoul(arg+7, &end, 0);
974 if (arg[7] && !*end) {
979 if (!strcmp(arg, "--inetd")) {
984 if (!strcmp(arg, "--verbose")) {
988 if (!strcmp(arg, "--syslog")) {
992 if (!strcmp(arg, "--export-all")) {
993 export_all_trees = 1;
996 if (!prefixcmp(arg, "--timeout=")) {
997 timeout = atoi(arg+10);
1000 if (!prefixcmp(arg, "--init-timeout=")) {
1001 init_timeout = atoi(arg+15);
1004 if (!prefixcmp(arg, "--max-connections=")) {
1005 max_connections = atoi(arg+18);
1006 if (max_connections < 0)
1007 max_connections = 0; /* unlimited */
1010 if (!strcmp(arg, "--strict-paths")) {
1014 if (!prefixcmp(arg, "--base-path=")) {
1018 if (!strcmp(arg, "--base-path-relaxed")) {
1019 base_path_relaxed = 1;
1022 if (!prefixcmp(arg, "--interpolated-path=")) {
1023 interpolated_path = arg+20;
1026 if (!strcmp(arg, "--reuseaddr")) {
1030 if (!strcmp(arg, "--user-path")) {
1034 if (!prefixcmp(arg, "--user-path=")) {
1035 user_path = arg + 12;
1038 if (!prefixcmp(arg, "--pid-file=")) {
1039 pid_file = arg + 11;
1042 if (!strcmp(arg, "--detach")) {
1047 if (!prefixcmp(arg, "--user=")) {
1048 user_name = arg + 7;
1051 if (!prefixcmp(arg, "--group=")) {
1052 group_name = arg + 8;
1055 if (!prefixcmp(arg, "--enable=")) {
1056 enable_service(arg + 9, 1);
1059 if (!prefixcmp(arg, "--disable=")) {
1060 enable_service(arg + 10, 0);
1063 if (!prefixcmp(arg, "--allow-override=")) {
1064 make_service_overridable(arg + 17, 1);
1067 if (!prefixcmp(arg, "--forbid-override=")) {
1068 make_service_overridable(arg + 18, 0);
1071 if (!strcmp(arg, "--")) {
1072 ok_paths = &argv[i+1];
1074 } else if (arg[0] != '-') {
1075 ok_paths = &argv[i];
1079 usage(daemon_usage);
1083 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1084 set_die_routine(daemon_die);
1086 setlinebuf(stderr); /* avoid splitting a message in the middle */
1088 if (inetd_mode && (group_name || user_name))
1089 die("--user and --group are incompatible with --inetd");
1091 if (inetd_mode && (listen_port || listen_addr))
1092 die("--listen= and --port= are incompatible with --inetd");
1093 else if (listen_port == 0)
1094 listen_port = DEFAULT_GIT_PORT;
1096 if (group_name && !user_name)
1097 die("--group supplied without --user");
1100 pass = getpwnam(user_name);
1102 die("user not found - %s", user_name);
1107 group = getgrnam(group_name);
1109 die("group not found - %s", group_name);
1111 gid = group->gr_gid;
1115 if (strict_paths && (!ok_paths || !*ok_paths))
1116 die("option --strict-paths requires a whitelist");
1121 if (stat(base_path, &st) || !S_ISDIR(st.st_mode))
1122 die("base-path '%s' does not exist or "
1123 "is not a directory", base_path);
1127 struct sockaddr_storage ss;
1128 struct sockaddr *peer = (struct sockaddr *)&ss;
1129 socklen_t slen = sizeof(ss);
1131 freopen("/dev/null", "w", stderr);
1133 if (getpeername(0, peer, &slen))
1136 return execute(peer);
1141 loginfo("Ready to rumble");
1147 store_pid(pid_file);
1149 return serve(listen_addr, listen_port, pass, gid);