3 #include <sys/socket.h>
7 #include <netinet/in.h>
14 static int log_syslog
;
18 static const char daemon_usage
[] =
19 "git-daemon [--verbose] [--syslog] [--inetd | --port=n] [--export-all]\n"
20 " [--timeout=n] [--init-timeout=n] [--strict-paths]\n"
21 " [--base-path=path] [--reuseaddr] [directory...]";
23 /* List of acceptable pathname prefixes */
24 static char **ok_paths
= NULL
;
25 static int strict_paths
= 0;
27 /* If this is set, git-daemon-export-ok is not required */
28 static int export_all_trees
= 0;
30 /* Take all paths relative to this one if non-NULL */
31 static char *base_path
= NULL
;
33 /* Timeout, and initial timeout */
34 static unsigned int timeout
= 0;
35 static unsigned int init_timeout
= 0;
37 static void logreport(int priority
, const char *err
, va_list params
)
39 /* We should do a single write so that it is atomic and output
40 * of several processes do not get intermingled. */
45 /* sizeof(buf) should be big enough for "[pid] \n" */
46 buflen
= snprintf(buf
, sizeof(buf
), "[%ld] ", (long) getpid());
48 maxlen
= sizeof(buf
) - buflen
- 1; /* -1 for our own LF */
49 msglen
= vsnprintf(buf
+ buflen
, maxlen
, err
, params
);
52 syslog(priority
, "%s", buf
);
56 /* maxlen counted our own LF but also counts space given to
57 * vsnprintf for the terminating NUL. We want to make sure that
58 * we have space for our own LF and NUL after the "meat" of the
59 * message, so truncate it at maxlen - 1.
61 if (msglen
> maxlen
- 1)
64 msglen
= 0; /* Protect against weird return values. */
70 write(2, buf
, buflen
);
73 static void logerror(const char *err
, ...)
76 va_start(params
, err
);
77 logreport(LOG_ERR
, err
, params
);
81 static void loginfo(const char *err
, ...)
86 va_start(params
, err
);
87 logreport(LOG_INFO
, err
, params
);
91 static int avoid_alias(char *p
)
96 * This resurrects the belts and suspenders paranoia check by HPA
97 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
98 * does not do getcwd() based path canonicalizations.
100 * sl becomes true immediately after seeing '/' and continues to
101 * be true as long as dots continue after that without intervening
104 if (!p
|| (*p
!= '/' && *p
!= '~'))
114 else if (ch
== '/') {
116 /* reject //, /./ and /../ */
121 if (0 < ndot
&& ndot
< 3)
122 /* reject /.$ and /..$ */
131 else if (ch
== '/') {
138 static char *path_ok(char *dir
)
142 if (avoid_alias(dir
)) {
143 logerror("'%s': aliased", dir
);
148 static char rpath
[PATH_MAX
];
149 if (!strict_paths
&& *dir
== '~')
150 ; /* allow user relative paths */
151 else if (*dir
!= '/') {
152 /* otherwise allow only absolute */
153 logerror("'%s': Non-absolute path denied (base-path active)", dir
);
157 snprintf(rpath
, PATH_MAX
, "%s%s", base_path
, dir
);
162 path
= enter_repo(dir
, strict_paths
);
165 logerror("'%s': unable to chdir or not a git archive", dir
);
169 if ( ok_paths
&& *ok_paths
) {
171 int pathlen
= strlen(path
);
173 /* The validation is done on the paths after enter_repo
174 * appends optional {.git,.git/.git} and friends, but
175 * it does not use getcwd(). So if your /pub is
176 * a symlink to /mnt/pub, you can whitelist /pub and
177 * do not have to say /mnt/pub.
180 for ( pp
= ok_paths
; *pp
; pp
++ ) {
181 int len
= strlen(*pp
);
182 if (len
<= pathlen
&&
183 !memcmp(*pp
, path
, len
) &&
184 (path
[len
] == '\0' ||
185 (!strict_paths
&& path
[len
] == '/')))
190 /* be backwards compatible */
195 logerror("'%s': not in whitelist", path
);
196 return NULL
; /* Fallthrough. Deny by default */
199 static int upload(char *dir
)
201 /* Timeout as string */
202 char timeout_buf
[64];
205 loginfo("Request for '%s'", dir
);
207 if (!(path
= path_ok(dir
)))
211 * Security on the cheap.
213 * We want a readable HEAD, usable "objects" directory, and
214 * a "git-daemon-export-ok" flag that says that the other side
215 * is ok with us doing this.
217 * path_ok() uses enter_repo() and does whitelist checking.
218 * We only need to make sure the repository is exported.
221 if (!export_all_trees
&& access("git-daemon-export-ok", F_OK
)) {
222 logerror("'%s': repository not exported.", path
);
228 * We'll ignore SIGTERM from now on, we have a
231 signal(SIGTERM
, SIG_IGN
);
233 snprintf(timeout_buf
, sizeof timeout_buf
, "--timeout=%u", timeout
);
235 /* git-upload-pack only ever reads stuff, so this is safe */
236 execl_git_cmd("upload-pack", "--strict", timeout_buf
, ".", NULL
);
240 static int execute(void)
242 static char line
[1000];
245 alarm(init_timeout
? init_timeout
: timeout
);
246 len
= packet_read_line(0, line
, sizeof(line
));
249 if (len
&& line
[len
-1] == '\n')
252 if (!strncmp("git-upload-pack ", line
, 16))
253 return upload(line
+16);
255 logerror("Protocol error: '%s'", line
);
261 * We count spawned/reaped separately, just to avoid any
262 * races when updating them from signals. The SIGCHLD handler
263 * will only update children_reaped, and the fork logic will
264 * only update children_spawned.
266 * MAX_CHILDREN should be a power-of-two to make the modulus
267 * operation cheap. It should also be at least twice
268 * the maximum number of connections we will ever allow.
270 #define MAX_CHILDREN 128
272 static int max_connections
= 25;
274 /* These are updated by the signal handler */
275 static volatile unsigned int children_reaped
= 0;
276 static pid_t dead_child
[MAX_CHILDREN
];
278 /* These are updated by the main loop */
279 static unsigned int children_spawned
= 0;
280 static unsigned int children_deleted
= 0;
282 static struct child
{
285 struct sockaddr_storage address
;
286 } live_child
[MAX_CHILDREN
];
288 static void add_child(int idx
, pid_t pid
, struct sockaddr
*addr
, int addrlen
)
290 live_child
[idx
].pid
= pid
;
291 live_child
[idx
].addrlen
= addrlen
;
292 memcpy(&live_child
[idx
].address
, addr
, addrlen
);
296 * Walk from "deleted" to "spawned", and remove child "pid".
298 * We move everything up by one, since the new "deleted" will
301 static void remove_child(pid_t pid
, unsigned deleted
, unsigned spawned
)
305 deleted
%= MAX_CHILDREN
;
306 spawned
%= MAX_CHILDREN
;
307 if (live_child
[deleted
].pid
== pid
) {
308 live_child
[deleted
].pid
= -1;
311 n
= live_child
[deleted
];
314 deleted
= (deleted
+ 1) % MAX_CHILDREN
;
315 if (deleted
== spawned
)
316 die("could not find dead child %d\n", pid
);
317 m
= live_child
[deleted
];
318 live_child
[deleted
] = n
;
326 * This gets called if the number of connections grows
327 * past "max_connections".
329 * We _should_ start off by searching for connections
330 * from the same IP, and if there is some address wth
331 * multiple connections, we should kill that first.
333 * As it is, we just "randomly" kill 25% of the connections,
334 * and our pseudo-random generator sucks too. I have no
337 * Really, this is just a place-holder for a _real_ algorithm.
339 static void kill_some_children(int signo
, unsigned start
, unsigned stop
)
341 start
%= MAX_CHILDREN
;
342 stop
%= MAX_CHILDREN
;
343 while (start
!= stop
) {
345 kill(live_child
[start
].pid
, signo
);
346 start
= (start
+ 1) % MAX_CHILDREN
;
350 static void check_max_connections(void)
354 unsigned spawned
, reaped
, deleted
;
356 spawned
= children_spawned
;
357 reaped
= children_reaped
;
358 deleted
= children_deleted
;
360 while (deleted
< reaped
) {
361 pid_t pid
= dead_child
[deleted
% MAX_CHILDREN
];
362 remove_child(pid
, deleted
, spawned
);
365 children_deleted
= deleted
;
367 active
= spawned
- deleted
;
368 if (active
<= max_connections
)
371 /* Kill some unstarted connections with SIGTERM */
372 kill_some_children(SIGTERM
, deleted
, spawned
);
373 if (active
<= max_connections
<< 1)
376 /* If the SIGTERM thing isn't helping use SIGKILL */
377 kill_some_children(SIGKILL
, deleted
, spawned
);
382 static void handle(int incoming
, struct sockaddr
*addr
, int addrlen
)
385 char addrbuf
[256] = "";
395 idx
= children_spawned
% MAX_CHILDREN
;
397 add_child(idx
, pid
, addr
, addrlen
);
399 check_max_connections();
407 if (addr
->sa_family
== AF_INET
) {
408 struct sockaddr_in
*sin_addr
= (void *) addr
;
409 inet_ntop(AF_INET
, &sin_addr
->sin_addr
, addrbuf
, sizeof(addrbuf
));
410 port
= sin_addr
->sin_port
;
413 } else if (addr
->sa_family
== AF_INET6
) {
414 struct sockaddr_in6
*sin6_addr
= (void *) addr
;
417 *buf
++ = '['; *buf
= '\0'; /* stpcpy() is cool */
418 inet_ntop(AF_INET6
, &sin6_addr
->sin6_addr
, buf
, sizeof(addrbuf
) - 1);
421 port
= sin6_addr
->sin6_port
;
424 loginfo("Connection from %s:%d", addrbuf
, port
);
429 static void child_handler(int signo
)
433 pid_t pid
= waitpid(-1, &status
, WNOHANG
);
436 unsigned reaped
= children_reaped
;
437 dead_child
[reaped
% MAX_CHILDREN
] = pid
;
438 children_reaped
= reaped
+ 1;
439 /* XXX: Custom logging, since we don't wanna getpid() */
442 if (!WIFEXITED(status
) || WEXITSTATUS(status
) > 0)
443 dead
= " (with error)";
445 syslog(LOG_INFO
, "[%d] Disconnected%s", pid
, dead
);
447 fprintf(stderr
, "[%d] Disconnected%s\n", pid
, dead
);
455 static int set_reuse_addr(int sockfd
)
461 return setsockopt(sockfd
, SOL_SOCKET
, SO_REUSEADDR
,
467 static int socksetup(int port
, int **socklist_p
)
469 int socknum
= 0, *socklist
= NULL
;
471 char pbuf
[NI_MAXSERV
];
473 struct addrinfo hints
, *ai0
, *ai
;
476 sprintf(pbuf
, "%d", port
);
477 memset(&hints
, 0, sizeof(hints
));
478 hints
.ai_family
= AF_UNSPEC
;
479 hints
.ai_socktype
= SOCK_STREAM
;
480 hints
.ai_protocol
= IPPROTO_TCP
;
481 hints
.ai_flags
= AI_PASSIVE
;
483 gai
= getaddrinfo(NULL
, pbuf
, &hints
, &ai0
);
485 die("getaddrinfo() failed: %s\n", gai_strerror(gai
));
487 for (ai
= ai0
; ai
; ai
= ai
->ai_next
) {
491 sockfd
= socket(ai
->ai_family
, ai
->ai_socktype
, ai
->ai_protocol
);
494 if (sockfd
>= FD_SETSIZE
) {
495 error("too large socket descriptor.");
501 if (ai
->ai_family
== AF_INET6
) {
503 setsockopt(sockfd
, IPPROTO_IPV6
, IPV6_V6ONLY
,
505 /* Note: error is not fatal */
509 if (set_reuse_addr(sockfd
)) {
511 return 0; /* not fatal */
514 if (bind(sockfd
, ai
->ai_addr
, ai
->ai_addrlen
) < 0) {
516 continue; /* not fatal */
518 if (listen(sockfd
, 5) < 0) {
520 continue; /* not fatal */
523 newlist
= realloc(socklist
, sizeof(int) * (socknum
+ 1));
525 die("memory allocation failed: %s", strerror(errno
));
528 socklist
[socknum
++] = sockfd
;
536 *socklist_p
= socklist
;
542 static int socksetup(int port
, int **socklist_p
)
544 struct sockaddr_in sin
;
547 sockfd
= socket(AF_INET
, SOCK_STREAM
, 0);
551 memset(&sin
, 0, sizeof sin
);
552 sin
.sin_family
= AF_INET
;
553 sin
.sin_addr
.s_addr
= htonl(INADDR_ANY
);
554 sin
.sin_port
= htons(port
);
556 if (set_reuse_addr(sockfd
)) {
561 if ( bind(sockfd
, (struct sockaddr
*)&sin
, sizeof sin
) < 0 ) {
566 if (listen(sockfd
, 5) < 0) {
571 *socklist_p
= xmalloc(sizeof(int));
572 **socklist_p
= sockfd
;
578 static int service_loop(int socknum
, int *socklist
)
583 pfd
= xcalloc(socknum
, sizeof(struct pollfd
));
585 for (i
= 0; i
< socknum
; i
++) {
586 pfd
[i
].fd
= socklist
[i
];
587 pfd
[i
].events
= POLLIN
;
590 signal(SIGCHLD
, child_handler
);
595 if (poll(pfd
, socknum
, -1) < 0) {
596 if (errno
!= EINTR
) {
597 error("poll failed, resuming: %s",
604 for (i
= 0; i
< socknum
; i
++) {
605 if (pfd
[i
].revents
& POLLIN
) {
606 struct sockaddr_storage ss
;
607 unsigned int sslen
= sizeof(ss
);
608 int incoming
= accept(pfd
[i
].fd
, (struct sockaddr
*)&ss
, &sslen
);
616 die("accept returned %s", strerror(errno
));
619 handle(incoming
, (struct sockaddr
*)&ss
, sslen
);
625 static int serve(int port
)
627 int socknum
, *socklist
;
629 socknum
= socksetup(port
, &socklist
);
631 die("unable to allocate any listen sockets on port %u", port
);
633 return service_loop(socknum
, socklist
);
636 int main(int argc
, char **argv
)
638 int port
= DEFAULT_GIT_PORT
;
642 for (i
= 1; i
< argc
; i
++) {
645 if (!strncmp(arg
, "--port=", 7)) {
648 n
= strtoul(arg
+7, &end
, 0);
649 if (arg
[7] && !*end
) {
654 if (!strcmp(arg
, "--inetd")) {
659 if (!strcmp(arg
, "--verbose")) {
663 if (!strcmp(arg
, "--syslog")) {
667 if (!strcmp(arg
, "--export-all")) {
668 export_all_trees
= 1;
671 if (!strncmp(arg
, "--timeout=", 10)) {
672 timeout
= atoi(arg
+10);
675 if (!strncmp(arg
, "--init-timeout=", 15)) {
676 init_timeout
= atoi(arg
+15);
679 if (!strcmp(arg
, "--strict-paths")) {
683 if (!strncmp(arg
, "--base-path=", 12)) {
687 if (!strcmp(arg
, "--reuseaddr")) {
691 if (!strcmp(arg
, "--")) {
692 ok_paths
= &argv
[i
+1];
694 } else if (arg
[0] != '-') {
703 openlog("git-daemon", 0, LOG_DAEMON
);
705 if (strict_paths
&& (!ok_paths
|| !*ok_paths
)) {
707 die("git-daemon: option --strict-paths requires a whitelist");
709 logerror("option --strict-paths requires a whitelist");
714 fclose(stderr
); //FIXME: workaround