[PATCH] Old curl does not know about CURLOPT_SSLKEY
[git/git.git] / daemon.c
CommitLineData
a87e8be2
LT
1#include "cache.h"
2#include "pkt-line.h"
eaa94919
LT
3#include <signal.h>
4#include <sys/wait.h>
a87e8be2 5#include <sys/socket.h>
3cd6ecda 6#include <sys/time.h>
df076bdb 7#include <netdb.h>
a87e8be2 8#include <netinet/in.h>
f8ff0c06 9#include <arpa/inet.h>
9048fe1c 10#include <syslog.h>
f8ff0c06 11
9048fe1c 12static int log_syslog;
f8ff0c06
PB
13static int verbose;
14
4ae95682
PA
15static const char daemon_usage[] = "git-daemon [--verbose] [--syslog] [--inetd | --port=n] [--export-all] [directory...]";
16
17/* List of acceptable pathname prefixes */
18static char **ok_paths = NULL;
19
20/* If this is set, git-daemon-export-ok is not required */
21static int export_all_trees = 0;
f8ff0c06
PB
22
23
9048fe1c 24static void logreport(int priority, const char *err, va_list params)
f8ff0c06
PB
25{
26 /* We should do a single write so that it is atomic and output
27 * of several processes do not get intermingled. */
28 char buf[1024];
29 int buflen;
30 int maxlen, msglen;
31
32 /* sizeof(buf) should be big enough for "[pid] \n" */
1bedd4ca 33 buflen = snprintf(buf, sizeof(buf), "[%ld] ", (long) getpid());
f8ff0c06
PB
34
35 maxlen = sizeof(buf) - buflen - 1; /* -1 for our own LF */
36 msglen = vsnprintf(buf + buflen, maxlen, err, params);
37
9048fe1c
PB
38 if (log_syslog) {
39 syslog(priority, "%s", buf);
40 return;
41 }
42
f8ff0c06
PB
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.
47 */
48 if (msglen > maxlen - 1)
49 msglen = maxlen - 1;
50 else if (msglen < 0)
51 msglen = 0; /* Protect against weird return values. */
52 buflen += msglen;
53
54 buf[buflen++] = '\n';
55 buf[buflen] = '\0';
56
57 write(2, buf, buflen);
58}
59
60void logerror(const char *err, ...)
61{
62 va_list params;
63 va_start(params, err);
9048fe1c 64 logreport(LOG_ERR, err, params);
f8ff0c06
PB
65 va_end(params);
66}
67
da38641d 68void loginfo(const char *err, ...)
f8ff0c06
PB
69{
70 va_list params;
71 if (!verbose)
72 return;
73 va_start(params, err);
9048fe1c 74 logreport(LOG_INFO, err, params);
f8ff0c06
PB
75 va_end(params);
76}
a87e8be2 77
4ae95682
PA
78static int path_ok(const char *dir)
79{
80 const char *p = dir;
81 char **pp;
82 int sl = 1, ndot = 0;
83
84 for (;;) {
85 if ( *p == '.' ) {
86 ndot++;
87 } else if ( *p == '/' || *p == '\0' ) {
88 if ( sl && ndot > 0 && ndot < 3 )
89 return 0; /* . or .. in path */
90 sl = 1;
91 if ( *p == '\0' )
92 break; /* End of string and all is good */
93 } else {
94 sl = ndot = 0;
95 }
96 p++;
97 }
98
99 if ( ok_paths && *ok_paths ) {
100 int ok = 0;
101 int dirlen = strlen(dir); /* read_packet_line can return embedded \0 */
102
103 for ( pp = ok_paths ; *pp ; pp++ ) {
104 int len = strlen(*pp);
105 if ( len <= dirlen &&
106 !strncmp(*pp, dir, len) &&
107 (dir[len] == '/' || dir[len] == '\0') ) {
108 ok = 1;
109 break;
110 }
111 }
112
113 if ( !ok )
114 return 0; /* Path not in whitelist */
115 }
116
117 return 1; /* Path acceptable */
118}
a87e8be2
LT
119
120static int upload(char *dir, int dirlen)
121{
da38641d 122 loginfo("Request for '%s'", dir);
4ae95682
PA
123
124 if (!path_ok(dir)) {
125 logerror("Forbidden directory: %s\n", dir);
126 return -1;
127 }
128
f8ff0c06
PB
129 if (chdir(dir) < 0) {
130 logerror("Cannot chdir('%s'): %s", dir, strerror(errno));
a87e8be2 131 return -1;
f8ff0c06 132 }
a87e8be2 133
47888f0f
PA
134 chdir(".git");
135
a87e8be2
LT
136 /*
137 * Security on the cheap.
138 *
139 * We want a readable HEAD, usable "objects" directory, and
140 * a "git-daemon-export-ok" flag that says that the other side
141 * is ok with us doing this.
142 */
4ae95682 143 if ((!export_all_trees && access("git-daemon-export-ok", F_OK)) ||
a87e8be2 144 access("objects/00", X_OK) ||
f8ff0c06 145 access("HEAD", R_OK)) {
4ae95682 146 logerror("Not a valid git-daemon-enabled repository: '%s'", dir);
a87e8be2 147 return -1;
f8ff0c06 148 }
a87e8be2 149
02d57da4
LT
150 /*
151 * We'll ignore SIGTERM from now on, we have a
152 * good client.
153 */
154 signal(SIGTERM, SIG_IGN);
155
a87e8be2
LT
156 /* git-upload-pack only ever reads stuff, so this is safe */
157 execlp("git-upload-pack", "git-upload-pack", ".", NULL);
158 return -1;
159}
160
7d80694a 161static int execute(void)
a87e8be2 162{
7d80694a
LT
163 static char line[1000];
164 int len;
165
166 len = packet_read_line(0, line, sizeof(line));
167
168 if (len && line[len-1] == '\n')
169 line[--len] = 0;
170
a87e8be2
LT
171 if (!strncmp("git-upload-pack /", line, 17))
172 return upload(line + 16, len - 16);
173
f8ff0c06 174 logerror("Protocol error: '%s'", line);
a87e8be2
LT
175 return -1;
176}
177
66e631de
LT
178
179/*
180 * We count spawned/reaped separately, just to avoid any
181 * races when updating them from signals. The SIGCHLD handler
182 * will only update children_reaped, and the fork logic will
183 * only update children_spawned.
184 *
185 * MAX_CHILDREN should be a power-of-two to make the modulus
186 * operation cheap. It should also be at least twice
187 * the maximum number of connections we will ever allow.
188 */
189#define MAX_CHILDREN 128
190
191static int max_connections = 25;
192
193/* These are updated by the signal handler */
194static volatile unsigned int children_reaped = 0;
4d8fa916 195static pid_t dead_child[MAX_CHILDREN];
66e631de
LT
196
197/* These are updated by the main loop */
198static unsigned int children_spawned = 0;
199static unsigned int children_deleted = 0;
200
4d8fa916 201static struct child {
66e631de 202 pid_t pid;
7fa09084 203 int addrlen;
df076bdb 204 struct sockaddr_storage address;
66e631de
LT
205} live_child[MAX_CHILDREN];
206
7fa09084 207static void add_child(int idx, pid_t pid, struct sockaddr *addr, int addrlen)
66e631de
LT
208{
209 live_child[idx].pid = pid;
210 live_child[idx].addrlen = addrlen;
df076bdb 211 memcpy(&live_child[idx].address, addr, addrlen);
66e631de
LT
212}
213
214/*
215 * Walk from "deleted" to "spawned", and remove child "pid".
216 *
217 * We move everything up by one, since the new "deleted" will
218 * be one higher.
219 */
220static void remove_child(pid_t pid, unsigned deleted, unsigned spawned)
221{
222 struct child n;
223
224 deleted %= MAX_CHILDREN;
225 spawned %= MAX_CHILDREN;
226 if (live_child[deleted].pid == pid) {
227 live_child[deleted].pid = -1;
228 return;
229 }
230 n = live_child[deleted];
231 for (;;) {
232 struct child m;
233 deleted = (deleted + 1) % MAX_CHILDREN;
234 if (deleted == spawned)
235 die("could not find dead child %d\n", pid);
236 m = live_child[deleted];
237 live_child[deleted] = n;
238 if (m.pid == pid)
239 return;
240 n = m;
241 }
242}
243
244/*
245 * This gets called if the number of connections grows
246 * past "max_connections".
247 *
248 * We _should_ start off by searching for connections
249 * from the same IP, and if there is some address wth
250 * multiple connections, we should kill that first.
251 *
252 * As it is, we just "randomly" kill 25% of the connections,
253 * and our pseudo-random generator sucks too. I have no
254 * shame.
255 *
256 * Really, this is just a place-holder for a _real_ algorithm.
257 */
02d57da4 258static void kill_some_children(int signo, unsigned start, unsigned stop)
66e631de
LT
259{
260 start %= MAX_CHILDREN;
261 stop %= MAX_CHILDREN;
262 while (start != stop) {
263 if (!(start & 3))
02d57da4 264 kill(live_child[start].pid, signo);
66e631de
LT
265 start = (start + 1) % MAX_CHILDREN;
266 }
267}
268
02d57da4 269static void check_max_connections(void)
a87e8be2 270{
02d57da4 271 for (;;) {
eaa94919 272 int active;
66e631de 273 unsigned spawned, reaped, deleted;
eaa94919 274
66e631de 275 spawned = children_spawned;
66e631de
LT
276 reaped = children_reaped;
277 deleted = children_deleted;
278
279 while (deleted < reaped) {
280 pid_t pid = dead_child[deleted % MAX_CHILDREN];
281 remove_child(pid, deleted, spawned);
282 deleted++;
283 }
284 children_deleted = deleted;
285
286 active = spawned - deleted;
02d57da4
LT
287 if (active <= max_connections)
288 break;
66e631de 289
02d57da4
LT
290 /* Kill some unstarted connections with SIGTERM */
291 kill_some_children(SIGTERM, deleted, spawned);
292 if (active <= max_connections << 1)
293 break;
294
295 /* If the SIGTERM thing isn't helping use SIGKILL */
296 kill_some_children(SIGKILL, deleted, spawned);
297 sleep(1);
298 }
299}
300
7fa09084 301static void handle(int incoming, struct sockaddr *addr, int addrlen)
02d57da4
LT
302{
303 pid_t pid = fork();
f8ff0c06
PB
304 char addrbuf[256] = "";
305 int port = -1;
02d57da4
LT
306
307 if (pid) {
308 unsigned idx;
309
310 close(incoming);
311 if (pid < 0)
312 return;
313
314 idx = children_spawned % MAX_CHILDREN;
315 children_spawned++;
316 add_child(idx, pid, addr, addrlen);
66e631de 317
02d57da4 318 check_max_connections();
a87e8be2
LT
319 return;
320 }
321
322 dup2(incoming, 0);
323 dup2(incoming, 1);
324 close(incoming);
f8ff0c06
PB
325
326 if (addr->sa_family == AF_INET) {
327 struct sockaddr_in *sin_addr = (void *) addr;
328 inet_ntop(AF_INET, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
329 port = sin_addr->sin_port;
330
331 } else if (addr->sa_family == AF_INET6) {
332 struct sockaddr_in6 *sin6_addr = (void *) addr;
333
334 char *buf = addrbuf;
335 *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
336 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
337 strcat(buf, "]");
338
339 port = sin6_addr->sin6_port;
340 }
da38641d 341 loginfo("Connection from %s:%d", addrbuf, port);
f8ff0c06 342
7d80694a 343 exit(execute());
a87e8be2
LT
344}
345
eaa94919
LT
346static void child_handler(int signo)
347{
348 for (;;) {
9048fe1c
PB
349 int status;
350 pid_t pid = waitpid(-1, &status, WNOHANG);
66e631de
LT
351
352 if (pid > 0) {
353 unsigned reaped = children_reaped;
354 dead_child[reaped % MAX_CHILDREN] = pid;
355 children_reaped = reaped + 1;
f8ff0c06 356 /* XXX: Custom logging, since we don't wanna getpid() */
9048fe1c
PB
357 if (verbose) {
358 char *dead = "";
359 if (!WIFEXITED(status) || WEXITSTATUS(status) > 0)
360 dead = " (with error)";
361 if (log_syslog)
362 syslog(LOG_INFO, "[%d] Disconnected%s", pid, dead);
363 else
364 fprintf(stderr, "[%d] Disconnected%s\n", pid, dead);
365 }
eaa94919
LT
366 continue;
367 }
368 break;
369 }
370}
371
a87e8be2
LT
372static int serve(int port)
373{
df076bdb
YH
374 struct addrinfo hints, *ai0, *ai;
375 int gai;
376 int socknum = 0, *socklist = NULL;
377 int maxfd = -1;
378 fd_set fds_init, fds;
379 char pbuf[NI_MAXSERV];
a87e8be2 380
eaa94919 381 signal(SIGCHLD, child_handler);
df076bdb
YH
382
383 sprintf(pbuf, "%d", port);
384 memset(&hints, 0, sizeof(hints));
385 hints.ai_family = AF_UNSPEC;
386 hints.ai_socktype = SOCK_STREAM;
387 hints.ai_protocol = IPPROTO_TCP;
388 hints.ai_flags = AI_PASSIVE;
389
390 gai = getaddrinfo(NULL, pbuf, &hints, &ai0);
391 if (gai)
392 die("getaddrinfo() failed: %s\n", gai_strerror(gai));
393
394 FD_ZERO(&fds_init);
395
396 for (ai = ai0; ai; ai = ai->ai_next) {
397 int sockfd;
398 int *newlist;
399
400 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
401 if (sockfd < 0)
402 continue;
403 if (sockfd >= FD_SETSIZE) {
404 error("too large socket descriptor.");
405 close(sockfd);
406 continue;
407 }
408
409#ifdef IPV6_V6ONLY
410 if (ai->ai_family == AF_INET6) {
411 int on = 1;
412 setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
413 &on, sizeof(on));
414 /* Note: error is not fatal */
415 }
416#endif
417
418 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
419 close(sockfd);
420 continue; /* not fatal */
421 }
422 if (listen(sockfd, 5) < 0) {
423 close(sockfd);
424 continue; /* not fatal */
425 }
426
427 newlist = realloc(socklist, sizeof(int) * (socknum + 1));
428 if (!newlist)
429 die("memory allocation failed: %s", strerror(errno));
430
431 socklist = newlist;
432 socklist[socknum++] = sockfd;
433
434 FD_SET(sockfd, &fds_init);
435 if (maxfd < sockfd)
436 maxfd = sockfd;
437 }
438
439 freeaddrinfo(ai0);
440
441 if (socknum == 0)
442 die("unable to allocate any listen sockets on port %u", port);
a87e8be2
LT
443
444 for (;;) {
df076bdb
YH
445 int i;
446 fds = fds_init;
447
448 if (select(maxfd + 1, &fds, NULL, NULL, NULL) < 0) {
1eef0b33
JH
449 if (errno != EINTR) {
450 error("select failed, resuming: %s",
451 strerror(errno));
452 sleep(1);
453 }
df076bdb
YH
454 continue;
455 }
456
457 for (i = 0; i < socknum; i++) {
458 int sockfd = socklist[i];
459
460 if (FD_ISSET(sockfd, &fds)) {
461 struct sockaddr_storage ss;
7fa09084 462 int sslen = sizeof(ss);
df076bdb
YH
463 int incoming = accept(sockfd, (struct sockaddr *)&ss, &sslen);
464 if (incoming < 0) {
465 switch (errno) {
466 case EAGAIN:
467 case EINTR:
468 case ECONNABORTED:
469 continue;
470 default:
471 die("accept returned %s", strerror(errno));
472 }
473 }
474 handle(incoming, (struct sockaddr *)&ss, sslen);
a87e8be2
LT
475 }
476 }
a87e8be2
LT
477 }
478}
479
480int main(int argc, char **argv)
481{
482 int port = DEFAULT_GIT_PORT;
e64e1b79 483 int inetd_mode = 0;
a87e8be2
LT
484 int i;
485
486 for (i = 1; i < argc; i++) {
487 char *arg = argv[i];
488
489 if (!strncmp(arg, "--port=", 7)) {
490 char *end;
491 unsigned long n;
492 n = strtoul(arg+7, &end, 0);
493 if (arg[7] && !*end) {
494 port = n;
495 continue;
496 }
497 }
e64e1b79
LT
498 if (!strcmp(arg, "--inetd")) {
499 inetd_mode = 1;
500 continue;
501 }
f8ff0c06
PB
502 if (!strcmp(arg, "--verbose")) {
503 verbose = 1;
504 continue;
505 }
9048fe1c
PB
506 if (!strcmp(arg, "--syslog")) {
507 log_syslog = 1;
508 openlog("git-daemon", 0, LOG_DAEMON);
509 continue;
510 }
4ae95682
PA
511 if (!strcmp(arg, "--export-all")) {
512 export_all_trees = 1;
513 continue;
514 }
515 if (!strcmp(arg, "--")) {
516 ok_paths = &argv[i+1];
517 break;
518 } else if (arg[0] != '-') {
519 ok_paths = &argv[i];
520 break;
521 }
e64e1b79 522
a87e8be2
LT
523 usage(daemon_usage);
524 }
525
7c3693f1
LD
526 if (inetd_mode) {
527 fclose(stderr); //FIXME: workaround
e64e1b79 528 return execute();
7c3693f1 529 }
e64e1b79 530
a87e8be2
LT
531 return serve(port);
532}