3 #include <sys/socket.h>
7 #include <netinet/in.h>
14 static int log_syslog
;
17 static const char daemon_usage
[] =
18 "git-daemon [--verbose] [--syslog] [--inetd | --port=n] [--export-all]\n"
19 " [--timeout=n] [--init-timeout=n] [--strict-paths]\n"
20 " [--base-path=path] [directory...]";
22 /* List of acceptable pathname prefixes */
23 static char **ok_paths
= NULL
;
24 static int strict_paths
= 0;
26 /* If this is set, git-daemon-export-ok is not required */
27 static int export_all_trees
= 0;
29 /* Take all paths relative to this one if non-NULL */
30 static char *base_path
= NULL
;
32 /* Timeout, and initial timeout */
33 static unsigned int timeout
= 0;
34 static unsigned int init_timeout
= 0;
36 static void logreport(int priority
, const char *err
, va_list params
)
38 /* We should do a single write so that it is atomic and output
39 * of several processes do not get intermingled. */
44 /* sizeof(buf) should be big enough for "[pid] \n" */
45 buflen
= snprintf(buf
, sizeof(buf
), "[%ld] ", (long) getpid());
47 maxlen
= sizeof(buf
) - buflen
- 1; /* -1 for our own LF */
48 msglen
= vsnprintf(buf
+ buflen
, maxlen
, err
, params
);
51 syslog(priority
, "%s", buf
);
55 /* maxlen counted our own LF but also counts space given to
56 * vsnprintf for the terminating NUL. We want to make sure that
57 * we have space for our own LF and NUL after the "meat" of the
58 * message, so truncate it at maxlen - 1.
60 if (msglen
> maxlen
- 1)
63 msglen
= 0; /* Protect against weird return values. */
69 write(2, buf
, buflen
);
72 static void logerror(const char *err
, ...)
75 va_start(params
, err
);
76 logreport(LOG_ERR
, err
, params
);
80 static void loginfo(const char *err
, ...)
85 va_start(params
, err
);
86 logreport(LOG_INFO
, err
, params
);
90 static int avoid_alias(char *p
)
95 * This resurrects the belts and suspenders paranoia check by HPA
96 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
97 * does not do getcwd() based path canonicalizations.
99 * sl becomes true immediately after seeing '/' and continues to
100 * be true as long as dots continue after that without intervening
103 if (!p
|| (*p
!= '/' && *p
!= '~'))
113 else if (ch
== '/') {
115 /* reject //, /./ and /../ */
120 if (0 < ndot
&& ndot
< 3)
121 /* reject /.$ and /..$ */
130 else if (ch
== '/') {
137 static char *path_ok(char *dir
)
141 if (avoid_alias(dir
)) {
142 logerror("'%s': aliased", dir
);
147 static char rpath
[PATH_MAX
];
148 if (!strict_paths
&& *dir
== '~')
149 ; /* allow user relative paths */
150 else if (*dir
!= '/') {
151 /* otherwise allow only absolute */
152 logerror("'%s': Non-absolute path denied (base-path active)", dir
);
156 snprintf(rpath
, PATH_MAX
, "%s%s", base_path
, dir
);
161 path
= enter_repo(dir
, strict_paths
);
164 logerror("'%s': unable to chdir or not a git archive", dir
);
168 if ( ok_paths
&& *ok_paths
) {
170 int pathlen
= strlen(path
);
172 /* The validation is done on the paths after enter_repo
173 * appends optional {.git,.git/.git} and friends, but
174 * it does not use getcwd(). So if your /pub is
175 * a symlink to /mnt/pub, you can whitelist /pub and
176 * do not have to say /mnt/pub.
179 for ( pp
= ok_paths
; *pp
; pp
++ ) {
180 int len
= strlen(*pp
);
181 if (len
<= pathlen
&&
182 !memcmp(*pp
, path
, len
) &&
183 (path
[len
] == '\0' ||
184 (!strict_paths
&& path
[len
] == '/')))
189 /* be backwards compatible */
194 logerror("'%s': not in whitelist", path
);
195 return NULL
; /* Fallthrough. Deny by default */
198 static int upload(char *dir
)
200 /* Timeout as string */
201 char timeout_buf
[64];
204 loginfo("Request for '%s'", dir
);
206 if (!(path
= path_ok(dir
)))
210 * Security on the cheap.
212 * We want a readable HEAD, usable "objects" directory, and
213 * a "git-daemon-export-ok" flag that says that the other side
214 * is ok with us doing this.
216 * path_ok() uses enter_repo() and does whitelist checking.
217 * We only need to make sure the repository is exported.
220 if (!export_all_trees
&& access("git-daemon-export-ok", F_OK
)) {
221 logerror("'%s': repository not exported.", path
);
227 * We'll ignore SIGTERM from now on, we have a
230 signal(SIGTERM
, SIG_IGN
);
232 snprintf(timeout_buf
, sizeof timeout_buf
, "--timeout=%u", timeout
);
234 /* git-upload-pack only ever reads stuff, so this is safe */
235 execl_git_cmd("upload-pack", "--strict", timeout_buf
, ".", NULL
);
239 static int execute(void)
241 static char line
[1000];
244 alarm(init_timeout
? init_timeout
: timeout
);
245 len
= packet_read_line(0, line
, sizeof(line
));
248 if (len
&& line
[len
-1] == '\n')
251 if (!strncmp("git-upload-pack ", line
, 16))
252 return upload(line
+16);
254 logerror("Protocol error: '%s'", line
);
260 * We count spawned/reaped separately, just to avoid any
261 * races when updating them from signals. The SIGCHLD handler
262 * will only update children_reaped, and the fork logic will
263 * only update children_spawned.
265 * MAX_CHILDREN should be a power-of-two to make the modulus
266 * operation cheap. It should also be at least twice
267 * the maximum number of connections we will ever allow.
269 #define MAX_CHILDREN 128
271 static int max_connections
= 25;
273 /* These are updated by the signal handler */
274 static volatile unsigned int children_reaped
= 0;
275 static pid_t dead_child
[MAX_CHILDREN
];
277 /* These are updated by the main loop */
278 static unsigned int children_spawned
= 0;
279 static unsigned int children_deleted
= 0;
281 static struct child
{
284 struct sockaddr_storage address
;
285 } live_child
[MAX_CHILDREN
];
287 static void add_child(int idx
, pid_t pid
, struct sockaddr
*addr
, int addrlen
)
289 live_child
[idx
].pid
= pid
;
290 live_child
[idx
].addrlen
= addrlen
;
291 memcpy(&live_child
[idx
].address
, addr
, addrlen
);
295 * Walk from "deleted" to "spawned", and remove child "pid".
297 * We move everything up by one, since the new "deleted" will
300 static void remove_child(pid_t pid
, unsigned deleted
, unsigned spawned
)
304 deleted
%= MAX_CHILDREN
;
305 spawned
%= MAX_CHILDREN
;
306 if (live_child
[deleted
].pid
== pid
) {
307 live_child
[deleted
].pid
= -1;
310 n
= live_child
[deleted
];
313 deleted
= (deleted
+ 1) % MAX_CHILDREN
;
314 if (deleted
== spawned
)
315 die("could not find dead child %d\n", pid
);
316 m
= live_child
[deleted
];
317 live_child
[deleted
] = n
;
325 * This gets called if the number of connections grows
326 * past "max_connections".
328 * We _should_ start off by searching for connections
329 * from the same IP, and if there is some address wth
330 * multiple connections, we should kill that first.
332 * As it is, we just "randomly" kill 25% of the connections,
333 * and our pseudo-random generator sucks too. I have no
336 * Really, this is just a place-holder for a _real_ algorithm.
338 static void kill_some_children(int signo
, unsigned start
, unsigned stop
)
340 start
%= MAX_CHILDREN
;
341 stop
%= MAX_CHILDREN
;
342 while (start
!= stop
) {
344 kill(live_child
[start
].pid
, signo
);
345 start
= (start
+ 1) % MAX_CHILDREN
;
349 static void check_max_connections(void)
353 unsigned spawned
, reaped
, deleted
;
355 spawned
= children_spawned
;
356 reaped
= children_reaped
;
357 deleted
= children_deleted
;
359 while (deleted
< reaped
) {
360 pid_t pid
= dead_child
[deleted
% MAX_CHILDREN
];
361 remove_child(pid
, deleted
, spawned
);
364 children_deleted
= deleted
;
366 active
= spawned
- deleted
;
367 if (active
<= max_connections
)
370 /* Kill some unstarted connections with SIGTERM */
371 kill_some_children(SIGTERM
, deleted
, spawned
);
372 if (active
<= max_connections
<< 1)
375 /* If the SIGTERM thing isn't helping use SIGKILL */
376 kill_some_children(SIGKILL
, deleted
, spawned
);
381 static void handle(int incoming
, struct sockaddr
*addr
, int addrlen
)
384 char addrbuf
[256] = "";
394 idx
= children_spawned
% MAX_CHILDREN
;
396 add_child(idx
, pid
, addr
, addrlen
);
398 check_max_connections();
406 if (addr
->sa_family
== AF_INET
) {
407 struct sockaddr_in
*sin_addr
= (void *) addr
;
408 inet_ntop(AF_INET
, &sin_addr
->sin_addr
, addrbuf
, sizeof(addrbuf
));
409 port
= sin_addr
->sin_port
;
412 } else if (addr
->sa_family
== AF_INET6
) {
413 struct sockaddr_in6
*sin6_addr
= (void *) addr
;
416 *buf
++ = '['; *buf
= '\0'; /* stpcpy() is cool */
417 inet_ntop(AF_INET6
, &sin6_addr
->sin6_addr
, buf
, sizeof(addrbuf
) - 1);
420 port
= sin6_addr
->sin6_port
;
423 loginfo("Connection from %s:%d", addrbuf
, port
);
428 static void child_handler(int signo
)
432 pid_t pid
= waitpid(-1, &status
, WNOHANG
);
435 unsigned reaped
= children_reaped
;
436 dead_child
[reaped
% MAX_CHILDREN
] = pid
;
437 children_reaped
= reaped
+ 1;
438 /* XXX: Custom logging, since we don't wanna getpid() */
441 if (!WIFEXITED(status
) || WEXITSTATUS(status
) > 0)
442 dead
= " (with error)";
444 syslog(LOG_INFO
, "[%d] Disconnected%s", pid
, dead
);
446 fprintf(stderr
, "[%d] Disconnected%s\n", pid
, dead
);
456 static int socksetup(int port
, int **socklist_p
)
458 int socknum
= 0, *socklist
= NULL
;
460 char pbuf
[NI_MAXSERV
];
462 struct addrinfo hints
, *ai0
, *ai
;
465 sprintf(pbuf
, "%d", port
);
466 memset(&hints
, 0, sizeof(hints
));
467 hints
.ai_family
= AF_UNSPEC
;
468 hints
.ai_socktype
= SOCK_STREAM
;
469 hints
.ai_protocol
= IPPROTO_TCP
;
470 hints
.ai_flags
= AI_PASSIVE
;
472 gai
= getaddrinfo(NULL
, pbuf
, &hints
, &ai0
);
474 die("getaddrinfo() failed: %s\n", gai_strerror(gai
));
476 for (ai
= ai0
; ai
; ai
= ai
->ai_next
) {
480 sockfd
= socket(ai
->ai_family
, ai
->ai_socktype
, ai
->ai_protocol
);
483 if (sockfd
>= FD_SETSIZE
) {
484 error("too large socket descriptor.");
490 if (ai
->ai_family
== AF_INET6
) {
492 setsockopt(sockfd
, IPPROTO_IPV6
, IPV6_V6ONLY
,
494 /* Note: error is not fatal */
498 if (bind(sockfd
, ai
->ai_addr
, ai
->ai_addrlen
) < 0) {
500 continue; /* not fatal */
502 if (listen(sockfd
, 5) < 0) {
504 continue; /* not fatal */
507 newlist
= realloc(socklist
, sizeof(int) * (socknum
+ 1));
509 die("memory allocation failed: %s", strerror(errno
));
512 socklist
[socknum
++] = sockfd
;
520 *socklist_p
= socklist
;
526 static int socksetup(int port
, int **socklist_p
)
528 struct sockaddr_in sin
;
531 sockfd
= socket(AF_INET
, SOCK_STREAM
, 0);
535 memset(&sin
, 0, sizeof sin
);
536 sin
.sin_family
= AF_INET
;
537 sin
.sin_addr
.s_addr
= htonl(INADDR_ANY
);
538 sin
.sin_port
= htons(port
);
540 if ( bind(sockfd
, (struct sockaddr
*)&sin
, sizeof sin
) < 0 ) {
545 if (listen(sockfd
, 5) < 0) {
550 *socklist_p
= xmalloc(sizeof(int));
551 **socklist_p
= sockfd
;
557 static int service_loop(int socknum
, int *socklist
)
562 pfd
= xcalloc(socknum
, sizeof(struct pollfd
));
564 for (i
= 0; i
< socknum
; i
++) {
565 pfd
[i
].fd
= socklist
[i
];
566 pfd
[i
].events
= POLLIN
;
569 signal(SIGCHLD
, child_handler
);
574 if (poll(pfd
, socknum
, -1) < 0) {
575 if (errno
!= EINTR
) {
576 error("poll failed, resuming: %s",
583 for (i
= 0; i
< socknum
; i
++) {
584 if (pfd
[i
].revents
& POLLIN
) {
585 struct sockaddr_storage ss
;
586 unsigned int sslen
= sizeof(ss
);
587 int incoming
= accept(pfd
[i
].fd
, (struct sockaddr
*)&ss
, &sslen
);
595 die("accept returned %s", strerror(errno
));
598 handle(incoming
, (struct sockaddr
*)&ss
, sslen
);
604 static int serve(int port
)
606 int socknum
, *socklist
;
608 socknum
= socksetup(port
, &socklist
);
610 die("unable to allocate any listen sockets on port %u", port
);
612 return service_loop(socknum
, socklist
);
615 int main(int argc
, char **argv
)
617 int port
= DEFAULT_GIT_PORT
;
621 for (i
= 1; i
< argc
; i
++) {
624 if (!strncmp(arg
, "--port=", 7)) {
627 n
= strtoul(arg
+7, &end
, 0);
628 if (arg
[7] && !*end
) {
633 if (!strcmp(arg
, "--inetd")) {
638 if (!strcmp(arg
, "--verbose")) {
642 if (!strcmp(arg
, "--syslog")) {
646 if (!strcmp(arg
, "--export-all")) {
647 export_all_trees
= 1;
650 if (!strncmp(arg
, "--timeout=", 10)) {
651 timeout
= atoi(arg
+10);
654 if (!strncmp(arg
, "--init-timeout=", 15)) {
655 init_timeout
= atoi(arg
+15);
658 if (!strcmp(arg
, "--strict-paths")) {
662 if (!strncmp(arg
, "--base-path=", 12)) {
666 if (!strcmp(arg
, "--")) {
667 ok_paths
= &argv
[i
+1];
669 } else if (arg
[0] != '-') {
678 openlog("git-daemon", 0, LOG_DAEMON
);
680 if (strict_paths
&& (!ok_paths
|| !*ok_paths
)) {
682 die("git-daemon: option --strict-paths requires a whitelist");
684 logerror("option --strict-paths requires a whitelist");
689 fclose(stderr
); //FIXME: workaround