5 #include <sys/socket.h>
8 #include <netinet/in.h>
12 static int log_syslog
;
15 static const char daemon_usage
[] = "git-daemon [--verbose] [--syslog] [--inetd | --port=n] [--export-all] [directory...]";
17 /* List of acceptable pathname prefixes */
18 static char **ok_paths
= NULL
;
20 /* If this is set, git-daemon-export-ok is not required */
21 static int export_all_trees
= 0;
24 static void logreport(int priority
, const char *err
, va_list params
)
26 /* We should do a single write so that it is atomic and output
27 * of several processes do not get intermingled. */
32 /* sizeof(buf) should be big enough for "[pid] \n" */
33 buflen
= snprintf(buf
, sizeof(buf
), "[%ld] ", (long) getpid());
35 maxlen
= sizeof(buf
) - buflen
- 1; /* -1 for our own LF */
36 msglen
= vsnprintf(buf
+ buflen
, maxlen
, err
, params
);
39 syslog(priority
, "%s", buf
);
43 /* maxlen counted our own LF but also counts space given to
44 * vsnprintf for the terminating NUL. We want to make sure that
45 * we have space for our own LF and NUL after the "meat" of the
46 * message, so truncate it at maxlen - 1.
48 if (msglen
> maxlen
- 1)
51 msglen
= 0; /* Protect against weird return values. */
57 write(2, buf
, buflen
);
60 static void logerror(const char *err
, ...)
63 va_start(params
, err
);
64 logreport(LOG_ERR
, err
, params
);
68 static void loginfo(const char *err
, ...)
73 va_start(params
, err
);
74 logreport(LOG_INFO
, err
, params
);
78 static int path_ok(const char *dir
)
84 /* The pathname here should be an absolute path. */
93 } else if ( *p
== '\0' ) {
94 /* Reject "." and ".." at the end of the path */
95 if ( sl
&& ndot
> 0 && ndot
< 3 )
100 } else if ( *p
== '/' ) {
101 /* Refuse "", "." or ".." */
102 if ( sl
&& ndot
< 3 )
112 if ( ok_paths
&& *ok_paths
) {
114 int dirlen
= strlen(dir
);
116 for ( pp
= ok_paths
; *pp
; pp
++ ) {
117 int len
= strlen(*pp
);
118 if ( len
<= dirlen
&&
119 !strncmp(*pp
, dir
, len
) &&
120 (dir
[len
] == '/' || dir
[len
] == '\0') ) {
127 return 0; /* Path not in whitelist */
130 return 1; /* Path acceptable */
133 static int set_dir(const char *dir
)
144 * Security on the cheap.
146 * We want a readable HEAD, usable "objects" directory, and
147 * a "git-daemon-export-ok" flag that says that the other side
148 * is ok with us doing this.
150 if (!export_all_trees
&& access("git-daemon-export-ok", F_OK
)) {
155 if (access("objects/", X_OK
) || access("HEAD", R_OK
)) {
160 /* If all this passed, we're OK */
164 static int upload(char *dir
)
166 /* Try paths in this order */
167 static const char *paths
[] = { "%s", "%s/.git", "%s.git", "%s.git/.git", NULL
};
169 /* Enough for the longest path above including final null */
170 int buflen
= strlen(dir
)+10;
171 char *dirbuf
= xmalloc(buflen
);
173 loginfo("Request for '%s'", dir
);
175 for ( pp
= paths
; *pp
; pp
++ ) {
176 snprintf(dirbuf
, buflen
, *pp
, dir
);
177 if ( !set_dir(dirbuf
) )
182 logerror("Cannot set directory '%s': %s", dir
, strerror(errno
));
187 * We'll ignore SIGTERM from now on, we have a
190 signal(SIGTERM
, SIG_IGN
);
192 /* git-upload-pack only ever reads stuff, so this is safe */
193 execlp("git-upload-pack", "git-upload-pack", ".", NULL
);
197 static int execute(void)
199 static char line
[1000];
202 len
= packet_read_line(0, line
, sizeof(line
));
204 if (len
&& line
[len
-1] == '\n')
207 if (!strncmp("git-upload-pack /", line
, 17))
208 return upload(line
+16);
210 logerror("Protocol error: '%s'", line
);
216 * We count spawned/reaped separately, just to avoid any
217 * races when updating them from signals. The SIGCHLD handler
218 * will only update children_reaped, and the fork logic will
219 * only update children_spawned.
221 * MAX_CHILDREN should be a power-of-two to make the modulus
222 * operation cheap. It should also be at least twice
223 * the maximum number of connections we will ever allow.
225 #define MAX_CHILDREN 128
227 static int max_connections
= 25;
229 /* These are updated by the signal handler */
230 static volatile unsigned int children_reaped
= 0;
231 static pid_t dead_child
[MAX_CHILDREN
];
233 /* These are updated by the main loop */
234 static unsigned int children_spawned
= 0;
235 static unsigned int children_deleted
= 0;
237 static struct child
{
240 struct sockaddr_storage address
;
241 } live_child
[MAX_CHILDREN
];
243 static void add_child(int idx
, pid_t pid
, struct sockaddr
*addr
, int addrlen
)
245 live_child
[idx
].pid
= pid
;
246 live_child
[idx
].addrlen
= addrlen
;
247 memcpy(&live_child
[idx
].address
, addr
, addrlen
);
251 * Walk from "deleted" to "spawned", and remove child "pid".
253 * We move everything up by one, since the new "deleted" will
256 static void remove_child(pid_t pid
, unsigned deleted
, unsigned spawned
)
260 deleted
%= MAX_CHILDREN
;
261 spawned
%= MAX_CHILDREN
;
262 if (live_child
[deleted
].pid
== pid
) {
263 live_child
[deleted
].pid
= -1;
266 n
= live_child
[deleted
];
269 deleted
= (deleted
+ 1) % MAX_CHILDREN
;
270 if (deleted
== spawned
)
271 die("could not find dead child %d\n", pid
);
272 m
= live_child
[deleted
];
273 live_child
[deleted
] = n
;
281 * This gets called if the number of connections grows
282 * past "max_connections".
284 * We _should_ start off by searching for connections
285 * from the same IP, and if there is some address wth
286 * multiple connections, we should kill that first.
288 * As it is, we just "randomly" kill 25% of the connections,
289 * and our pseudo-random generator sucks too. I have no
292 * Really, this is just a place-holder for a _real_ algorithm.
294 static void kill_some_children(int signo
, unsigned start
, unsigned stop
)
296 start
%= MAX_CHILDREN
;
297 stop
%= MAX_CHILDREN
;
298 while (start
!= stop
) {
300 kill(live_child
[start
].pid
, signo
);
301 start
= (start
+ 1) % MAX_CHILDREN
;
305 static void check_max_connections(void)
309 unsigned spawned
, reaped
, deleted
;
311 spawned
= children_spawned
;
312 reaped
= children_reaped
;
313 deleted
= children_deleted
;
315 while (deleted
< reaped
) {
316 pid_t pid
= dead_child
[deleted
% MAX_CHILDREN
];
317 remove_child(pid
, deleted
, spawned
);
320 children_deleted
= deleted
;
322 active
= spawned
- deleted
;
323 if (active
<= max_connections
)
326 /* Kill some unstarted connections with SIGTERM */
327 kill_some_children(SIGTERM
, deleted
, spawned
);
328 if (active
<= max_connections
<< 1)
331 /* If the SIGTERM thing isn't helping use SIGKILL */
332 kill_some_children(SIGKILL
, deleted
, spawned
);
337 static void handle(int incoming
, struct sockaddr
*addr
, int addrlen
)
340 char addrbuf
[256] = "";
350 idx
= children_spawned
% MAX_CHILDREN
;
352 add_child(idx
, pid
, addr
, addrlen
);
354 check_max_connections();
362 if (addr
->sa_family
== AF_INET
) {
363 struct sockaddr_in
*sin_addr
= (void *) addr
;
364 inet_ntop(AF_INET
, &sin_addr
->sin_addr
, addrbuf
, sizeof(addrbuf
));
365 port
= sin_addr
->sin_port
;
367 } else if (addr
->sa_family
== AF_INET6
) {
368 struct sockaddr_in6
*sin6_addr
= (void *) addr
;
371 *buf
++ = '['; *buf
= '\0'; /* stpcpy() is cool */
372 inet_ntop(AF_INET6
, &sin6_addr
->sin6_addr
, buf
, sizeof(addrbuf
) - 1);
375 port
= sin6_addr
->sin6_port
;
377 loginfo("Connection from %s:%d", addrbuf
, port
);
382 static void child_handler(int signo
)
386 pid_t pid
= waitpid(-1, &status
, WNOHANG
);
389 unsigned reaped
= children_reaped
;
390 dead_child
[reaped
% MAX_CHILDREN
] = pid
;
391 children_reaped
= reaped
+ 1;
392 /* XXX: Custom logging, since we don't wanna getpid() */
395 if (!WIFEXITED(status
) || WEXITSTATUS(status
) > 0)
396 dead
= " (with error)";
398 syslog(LOG_INFO
, "[%d] Disconnected%s", pid
, dead
);
400 fprintf(stderr
, "[%d] Disconnected%s\n", pid
, dead
);
408 static int serve(int port
)
410 struct addrinfo hints
, *ai0
, *ai
;
412 int socknum
= 0, *socklist
= NULL
;
414 fd_set fds_init
, fds
;
415 char pbuf
[NI_MAXSERV
];
417 signal(SIGCHLD
, child_handler
);
419 sprintf(pbuf
, "%d", port
);
420 memset(&hints
, 0, sizeof(hints
));
421 hints
.ai_family
= AF_UNSPEC
;
422 hints
.ai_socktype
= SOCK_STREAM
;
423 hints
.ai_protocol
= IPPROTO_TCP
;
424 hints
.ai_flags
= AI_PASSIVE
;
426 gai
= getaddrinfo(NULL
, pbuf
, &hints
, &ai0
);
428 die("getaddrinfo() failed: %s\n", gai_strerror(gai
));
432 for (ai
= ai0
; ai
; ai
= ai
->ai_next
) {
436 sockfd
= socket(ai
->ai_family
, ai
->ai_socktype
, ai
->ai_protocol
);
439 if (sockfd
>= FD_SETSIZE
) {
440 error("too large socket descriptor.");
446 if (ai
->ai_family
== AF_INET6
) {
448 setsockopt(sockfd
, IPPROTO_IPV6
, IPV6_V6ONLY
,
450 /* Note: error is not fatal */
454 if (bind(sockfd
, ai
->ai_addr
, ai
->ai_addrlen
) < 0) {
456 continue; /* not fatal */
458 if (listen(sockfd
, 5) < 0) {
460 continue; /* not fatal */
463 newlist
= realloc(socklist
, sizeof(int) * (socknum
+ 1));
465 die("memory allocation failed: %s", strerror(errno
));
468 socklist
[socknum
++] = sockfd
;
470 FD_SET(sockfd
, &fds_init
);
478 die("unable to allocate any listen sockets on port %u", port
);
484 if (select(maxfd
+ 1, &fds
, NULL
, NULL
, NULL
) < 0) {
485 if (errno
!= EINTR
) {
486 error("select failed, resuming: %s",
493 for (i
= 0; i
< socknum
; i
++) {
494 int sockfd
= socklist
[i
];
496 if (FD_ISSET(sockfd
, &fds
)) {
497 struct sockaddr_storage ss
;
498 int sslen
= sizeof(ss
);
499 int incoming
= accept(sockfd
, (struct sockaddr
*)&ss
, &sslen
);
507 die("accept returned %s", strerror(errno
));
510 handle(incoming
, (struct sockaddr
*)&ss
, sslen
);
516 int main(int argc
, char **argv
)
518 int port
= DEFAULT_GIT_PORT
;
522 for (i
= 1; i
< argc
; i
++) {
525 if (!strncmp(arg
, "--port=", 7)) {
528 n
= strtoul(arg
+7, &end
, 0);
529 if (arg
[7] && !*end
) {
534 if (!strcmp(arg
, "--inetd")) {
538 if (!strcmp(arg
, "--verbose")) {
542 if (!strcmp(arg
, "--syslog")) {
544 openlog("git-daemon", 0, LOG_DAEMON
);
547 if (!strcmp(arg
, "--export-all")) {
548 export_all_trees
= 1;
551 if (!strcmp(arg
, "--")) {
552 ok_paths
= &argv
[i
+1];
554 } else if (arg
[0] != '-') {
563 fclose(stderr
); //FIXME: workaround