Document 'git-blame --incremental'
[git/git.git] / daemon.c
CommitLineData
979e32fa 1#include "cache.h"
85023577 2#include "pkt-line.h"
77cb17e9 3#include "exec_cmd.h"
49ba83fb 4#include "interpolate.h"
f8ff0c06 5
85023577
JH
6#include <syslog.h>
7
695dffe2
JS
8#ifndef HOST_NAME_MAX
9#define HOST_NAME_MAX 256
10#endif
11
9048fe1c 12static int log_syslog;
f8ff0c06 13static int verbose;
1955fabf 14static int reuseaddr;
f8ff0c06 15
960deccb 16static const char daemon_usage[] =
dd467629 17"git-daemon [--verbose] [--syslog] [--export-all]\n"
b21c31c9 18" [--timeout=n] [--init-timeout=n] [--strict-paths]\n"
603968d2 19" [--base-path=path] [--user-path | --user-path=path]\n"
49ba83fb 20" [--interpolated-path=path]\n"
678dac6b 21" [--reuseaddr] [--detach] [--pid-file=file]\n"
d9edcbd6 22" [--[enable|disable|allow-override|forbid-override]=service]\n"
dd467629
JL
23" [--inetd | [--listen=host_or_ipaddr] [--port=n]\n"
24" [--user=user [--group=group]]\n"
25" [directory...]";
4ae95682
PA
26
27/* List of acceptable pathname prefixes */
96f1e58f
DR
28static char **ok_paths;
29static int strict_paths;
4ae95682
PA
30
31/* If this is set, git-daemon-export-ok is not required */
96f1e58f 32static int export_all_trees;
f8ff0c06 33
b21c31c9 34/* Take all paths relative to this one if non-NULL */
96f1e58f 35static char *base_path;
49ba83fb
JL
36static char *interpolated_path;
37
38/* Flag indicating client sent extra args. */
39static int saw_extended_args;
b21c31c9 40
603968d2
JH
41/* If defined, ~user notation is allowed and the string is inserted
42 * after ~user/. E.g. a request to git://host/~alice/frotz would
43 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
44 */
96f1e58f 45static const char *user_path;
603968d2 46
960deccb 47/* Timeout, and initial timeout */
96f1e58f
DR
48static unsigned int timeout;
49static unsigned int init_timeout;
f8ff0c06 50
49ba83fb
JL
51/*
52 * Static table for now. Ugh.
53 * Feel free to make dynamic as needed.
54 */
55#define INTERP_SLOT_HOST (0)
dd467629
JL
56#define INTERP_SLOT_CANON_HOST (1)
57#define INTERP_SLOT_IP (2)
58#define INTERP_SLOT_PORT (3)
59#define INTERP_SLOT_DIR (4)
60#define INTERP_SLOT_PERCENT (5)
49ba83fb
JL
61
62static struct interp interp_table[] = {
63 { "%H", 0},
dd467629
JL
64 { "%CH", 0},
65 { "%IP", 0},
66 { "%P", 0},
49ba83fb 67 { "%D", 0},
eb30aed7 68 { "%%", 0},
49ba83fb
JL
69};
70
71
9048fe1c 72static void logreport(int priority, const char *err, va_list params)
f8ff0c06
PB
73{
74 /* We should do a single write so that it is atomic and output
75 * of several processes do not get intermingled. */
76 char buf[1024];
77 int buflen;
78 int maxlen, msglen;
79
80 /* sizeof(buf) should be big enough for "[pid] \n" */
1bedd4ca 81 buflen = snprintf(buf, sizeof(buf), "[%ld] ", (long) getpid());
f8ff0c06
PB
82
83 maxlen = sizeof(buf) - buflen - 1; /* -1 for our own LF */
84 msglen = vsnprintf(buf + buflen, maxlen, err, params);
85
9048fe1c
PB
86 if (log_syslog) {
87 syslog(priority, "%s", buf);
88 return;
89 }
90
f8ff0c06
PB
91 /* maxlen counted our own LF but also counts space given to
92 * vsnprintf for the terminating NUL. We want to make sure that
93 * we have space for our own LF and NUL after the "meat" of the
94 * message, so truncate it at maxlen - 1.
95 */
96 if (msglen > maxlen - 1)
97 msglen = maxlen - 1;
98 else if (msglen < 0)
99 msglen = 0; /* Protect against weird return values. */
100 buflen += msglen;
101
102 buf[buflen++] = '\n';
103 buf[buflen] = '\0';
104
93822c22 105 write_in_full(2, buf, buflen);
f8ff0c06
PB
106}
107
cdda4745 108static void logerror(const char *err, ...)
f8ff0c06
PB
109{
110 va_list params;
111 va_start(params, err);
9048fe1c 112 logreport(LOG_ERR, err, params);
f8ff0c06
PB
113 va_end(params);
114}
115
cdda4745 116static void loginfo(const char *err, ...)
f8ff0c06
PB
117{
118 va_list params;
119 if (!verbose)
120 return;
121 va_start(params, err);
9048fe1c 122 logreport(LOG_INFO, err, params);
f8ff0c06
PB
123 va_end(params);
124}
a87e8be2 125
ad8b4f56
ML
126static void NORETURN daemon_die(const char *err, va_list params)
127{
128 logreport(LOG_ERR, err, params);
129 exit(1);
130}
131
d79374c7
JH
132static int avoid_alias(char *p)
133{
134 int sl, ndot;
135
136 /*
137 * This resurrects the belts and suspenders paranoia check by HPA
138 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
139 * does not do getcwd() based path canonicalizations.
140 *
141 * sl becomes true immediately after seeing '/' and continues to
142 * be true as long as dots continue after that without intervening
143 * non-dot character.
144 */
145 if (!p || (*p != '/' && *p != '~'))
146 return -1;
147 sl = 1; ndot = 0;
148 p++;
149
150 while (1) {
151 char ch = *p++;
152 if (sl) {
153 if (ch == '.')
154 ndot++;
155 else if (ch == '/') {
156 if (ndot < 3)
157 /* reject //, /./ and /../ */
158 return -1;
159 ndot = 0;
160 }
161 else if (ch == 0) {
162 if (0 < ndot && ndot < 3)
163 /* reject /.$ and /..$ */
164 return -1;
165 return 0;
166 }
167 else
168 sl = ndot = 0;
169 }
170 else if (ch == 0)
171 return 0;
172 else if (ch == '/') {
173 sl = 1;
174 ndot = 0;
175 }
176 }
177}
178
49ba83fb 179static char *path_ok(struct interp *itable)
4ae95682 180{
603968d2 181 static char rpath[PATH_MAX];
49ba83fb 182 static char interp_path[PATH_MAX];
d79374c7 183 char *path;
49ba83fb
JL
184 char *dir;
185
186 dir = itable[INTERP_SLOT_DIR].value;
d79374c7
JH
187
188 if (avoid_alias(dir)) {
189 logerror("'%s': aliased", dir);
190 return NULL;
191 }
192
603968d2
JH
193 if (*dir == '~') {
194 if (!user_path) {
195 logerror("'%s': User-path not allowed", dir);
196 return NULL;
197 }
198 if (*user_path) {
199 /* Got either "~alice" or "~alice/foo";
200 * rewrite them to "~alice/%s" or
201 * "~alice/%s/foo".
202 */
203 int namlen, restlen = strlen(dir);
204 char *slash = strchr(dir, '/');
205 if (!slash)
206 slash = dir + restlen;
207 namlen = slash - dir;
208 restlen -= namlen;
209 loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
210 snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
211 namlen, dir, user_path, restlen, slash);
212 dir = rpath;
213 }
214 }
49ba83fb
JL
215 else if (interpolated_path && saw_extended_args) {
216 if (*dir != '/') {
217 /* Allow only absolute */
218 logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
219 return NULL;
220 }
221
222 interpolate(interp_path, PATH_MAX, interpolated_path,
223 interp_table, ARRAY_SIZE(interp_table));
224 loginfo("Interpolated dir '%s'", interp_path);
225
226 dir = interp_path;
227 }
603968d2
JH
228 else if (base_path) {
229 if (*dir != '/') {
230 /* Allow only absolute */
1fda3d55 231 logerror("'%s': Non-absolute path denied (base-path active)", dir);
b21c31c9
PB
232 return NULL;
233 }
49ba83fb
JL
234 snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
235 dir = rpath;
b21c31c9
PB
236 }
237
d79374c7 238 path = enter_repo(dir, strict_paths);
3e04c62d 239
4dbd1352
AE
240 if (!path) {
241 logerror("'%s': unable to chdir or not a git archive", dir);
242 return NULL;
4ae95682
PA
243 }
244
245 if ( ok_paths && *ok_paths ) {
ce335fe0 246 char **pp;
4dbd1352 247 int pathlen = strlen(path);
4ae95682 248
ce335fe0 249 /* The validation is done on the paths after enter_repo
d79374c7
JH
250 * appends optional {.git,.git/.git} and friends, but
251 * it does not use getcwd(). So if your /pub is
252 * a symlink to /mnt/pub, you can whitelist /pub and
253 * do not have to say /mnt/pub.
254 * Do not say /pub/.
ce335fe0 255 */
4ae95682
PA
256 for ( pp = ok_paths ; *pp ; pp++ ) {
257 int len = strlen(*pp);
ce335fe0
JH
258 if (len <= pathlen &&
259 !memcmp(*pp, path, len) &&
260 (path[len] == '\0' ||
261 (!strict_paths && path[len] == '/')))
262 return path;
4ae95682 263 }
4dbd1352
AE
264 }
265 else {
266 /* be backwards compatible */
267 if (!strict_paths)
268 return path;
4ae95682
PA
269 }
270
4dbd1352
AE
271 logerror("'%s': not in whitelist", path);
272 return NULL; /* Fallthrough. Deny by default */
4ae95682 273}
a87e8be2 274
d819e4e6
JH
275typedef int (*daemon_service_fn)(void);
276struct daemon_service {
277 const char *name;
278 const char *config_name;
279 daemon_service_fn fn;
280 int enabled;
281 int overridable;
282};
283
284static struct daemon_service *service_looking_at;
285static int service_enabled;
286
287static int git_daemon_config(const char *var, const char *value)
288{
289 if (!strncmp(var, "daemon.", 7) &&
290 !strcmp(var + 7, service_looking_at->config_name)) {
291 service_enabled = git_config_bool(var, value);
292 return 0;
293 }
294
295 /* we are not interested in parsing any other configuration here */
296 return 0;
297}
298
49ba83fb 299static int run_service(struct interp *itable, struct daemon_service *service)
a87e8be2 300{
4dbd1352 301 const char *path;
d819e4e6
JH
302 int enabled = service->enabled;
303
49ba83fb
JL
304 loginfo("Request %s for '%s'",
305 service->name,
306 itable[INTERP_SLOT_DIR].value);
4dbd1352 307
d819e4e6
JH
308 if (!enabled && !service->overridable) {
309 logerror("'%s': service not enabled.", service->name);
310 errno = EACCES;
311 return -1;
312 }
4ae95682 313
49ba83fb 314 if (!(path = path_ok(itable)))
a87e8be2 315 return -1;
47888f0f 316
a87e8be2
LT
317 /*
318 * Security on the cheap.
319 *
a935c397 320 * We want a readable HEAD, usable "objects" directory, and
a87e8be2
LT
321 * a "git-daemon-export-ok" flag that says that the other side
322 * is ok with us doing this.
4dbd1352
AE
323 *
324 * path_ok() uses enter_repo() and does whitelist checking.
325 * We only need to make sure the repository is exported.
a87e8be2 326 */
4dbd1352 327
3e04c62d 328 if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
4dbd1352 329 logerror("'%s': repository not exported.", path);
3e04c62d
PA
330 errno = EACCES;
331 return -1;
332 }
333
d819e4e6
JH
334 if (service->overridable) {
335 service_looking_at = service;
336 service_enabled = -1;
337 git_config(git_daemon_config);
338 if (0 <= service_enabled)
339 enabled = service_enabled;
340 }
341 if (!enabled) {
342 logerror("'%s': service not enabled for '%s'",
343 service->name, path);
344 errno = EACCES;
345 return -1;
346 }
347
02d57da4
LT
348 /*
349 * We'll ignore SIGTERM from now on, we have a
350 * good client.
351 */
352 signal(SIGTERM, SIG_IGN);
353
d819e4e6
JH
354 return service->fn();
355}
356
357static int upload_pack(void)
358{
359 /* Timeout as string */
360 char timeout_buf[64];
361
960deccb
PA
362 snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
363
a87e8be2 364 /* git-upload-pack only ever reads stuff, so this is safe */
77cb17e9 365 execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL);
a87e8be2
LT
366 return -1;
367}
368
39345a21
FBH
369static int upload_archive(void)
370{
371 execl_git_cmd("upload-archive", ".", NULL);
372 return -1;
373}
374
d819e4e6 375static struct daemon_service daemon_service[] = {
39345a21 376 { "upload-archive", "uploadarch", upload_archive, 0, 1 },
d819e4e6
JH
377 { "upload-pack", "uploadpack", upload_pack, 1, 1 },
378};
379
380static void enable_service(const char *name, int ena) {
381 int i;
382 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
383 if (!strcmp(daemon_service[i].name, name)) {
384 daemon_service[i].enabled = ena;
385 return;
386 }
387 }
388 die("No such service %s", name);
389}
390
391static void make_service_overridable(const char *name, int ena) {
392 int i;
393 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
394 if (!strcmp(daemon_service[i].name, name)) {
395 daemon_service[i].overridable = ena;
396 return;
397 }
398 }
399 die("No such service %s", name);
400}
401
eb30aed7
JL
402/*
403 * Separate the "extra args" information as supplied by the client connection.
404 * Any resulting data is squirrelled away in the given interpolation table.
405 */
406static void parse_extra_args(struct interp *table, char *extra_args, int buflen)
49ba83fb
JL
407{
408 char *val;
409 int vallen;
410 char *end = extra_args + buflen;
411
412 while (extra_args < end && *extra_args) {
413 saw_extended_args = 1;
414 if (strncasecmp("host=", extra_args, 5) == 0) {
415 val = extra_args + 5;
416 vallen = strlen(val) + 1;
417 if (*val) {
eb30aed7
JL
418 /* Split <host>:<port> at colon. */
419 char *host = val;
420 char *port = strrchr(host, ':');
dd467629
JL
421 if (port) {
422 *port = 0;
423 port++;
eb30aed7 424 interp_set_entry(table, INTERP_SLOT_PORT, port);
dd467629 425 }
eb30aed7 426 interp_set_entry(table, INTERP_SLOT_HOST, host);
49ba83fb 427 }
eb30aed7 428
49ba83fb
JL
429 /* On to the next one */
430 extra_args = val + vallen;
431 }
432 }
433}
434
dd467629
JL
435void fill_in_extra_table_entries(struct interp *itable)
436{
437 char *hp;
dd467629
JL
438
439 /*
440 * Replace literal host with lowercase-ized hostname.
441 */
442 hp = interp_table[INTERP_SLOT_HOST].value;
83543a24
JH
443 if (!hp)
444 return;
dd467629
JL
445 for ( ; *hp; hp++)
446 *hp = tolower(*hp);
447
448 /*
449 * Locate canonical hostname and its IP address.
450 */
451#ifndef NO_IPV6
452 {
453 struct addrinfo hints;
454 struct addrinfo *ai, *ai0;
455 int gai;
456 static char addrbuf[HOST_NAME_MAX + 1];
457
458 memset(&hints, 0, sizeof(hints));
459 hints.ai_flags = AI_CANONNAME;
460
461 gai = getaddrinfo(interp_table[INTERP_SLOT_HOST].value, 0, &hints, &ai0);
462 if (!gai) {
463 for (ai = ai0; ai; ai = ai->ai_next) {
464 struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
465
dd467629
JL
466 inet_ntop(AF_INET, &sin_addr->sin_addr,
467 addrbuf, sizeof(addrbuf));
eb30aed7
JL
468 interp_set_entry(interp_table,
469 INTERP_SLOT_CANON_HOST, ai->ai_canonname);
470 interp_set_entry(interp_table,
471 INTERP_SLOT_IP, addrbuf);
dd467629
JL
472 break;
473 }
474 freeaddrinfo(ai0);
475 }
476 }
477#else
478 {
479 struct hostent *hent;
480 struct sockaddr_in sa;
481 char **ap;
482 static char addrbuf[HOST_NAME_MAX + 1];
483
484 hent = gethostbyname(interp_table[INTERP_SLOT_HOST].value);
dd467629
JL
485
486 ap = hent->h_addr_list;
487 memset(&sa, 0, sizeof sa);
488 sa.sin_family = hent->h_addrtype;
489 sa.sin_port = htons(0);
490 memcpy(&sa.sin_addr, *ap, hent->h_length);
491
492 inet_ntop(hent->h_addrtype, &sa.sin_addr,
493 addrbuf, sizeof(addrbuf));
eb30aed7
JL
494
495 interp_set_entry(interp_table, INTERP_SLOT_CANON_HOST, hent->h_name);
496 interp_set_entry(interp_table, INTERP_SLOT_IP, addrbuf);
dd467629
JL
497 }
498#endif
dd467629
JL
499}
500
501
5b276ee4 502static int execute(struct sockaddr *addr)
a87e8be2 503{
7d80694a 504 static char line[1000];
d819e4e6 505 int pktlen, len, i;
7d80694a 506
5b276ee4
DW
507 if (addr) {
508 char addrbuf[256] = "";
509 int port = -1;
510
511 if (addr->sa_family == AF_INET) {
512 struct sockaddr_in *sin_addr = (void *) addr;
513 inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
514 port = sin_addr->sin_port;
515#ifndef NO_IPV6
516 } else if (addr && addr->sa_family == AF_INET6) {
517 struct sockaddr_in6 *sin6_addr = (void *) addr;
518
519 char *buf = addrbuf;
520 *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
521 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
522 strcat(buf, "]");
523
524 port = sin6_addr->sin6_port;
525#endif
526 }
527 loginfo("Connection from %s:%d", addrbuf, port);
528 }
529
960deccb 530 alarm(init_timeout ? init_timeout : timeout);
5ad312be 531 pktlen = packet_read_line(0, line, sizeof(line));
960deccb 532 alarm(0);
7d80694a 533
5ad312be
JL
534 len = strlen(line);
535 if (pktlen != len)
536 loginfo("Extended attributes (%d bytes) exist <%.*s>",
537 (int) pktlen - len,
538 (int) pktlen - len, line + len + 1);
83543a24 539 if (len && line[len-1] == '\n') {
7d80694a 540 line[--len] = 0;
83543a24
JH
541 pktlen--;
542 }
7d80694a 543
eb30aed7
JL
544 /*
545 * Initialize the path interpolation table for this connection.
546 */
547 interp_clear_table(interp_table, ARRAY_SIZE(interp_table));
548 interp_set_entry(interp_table, INTERP_SLOT_PERCENT, "%");
549
dd467629 550 if (len != pktlen) {
eb30aed7 551 parse_extra_args(interp_table, line + len + 1, pktlen - len - 1);
dd467629
JL
552 fill_in_extra_table_entries(interp_table);
553 }
49ba83fb 554
d819e4e6
JH
555 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
556 struct daemon_service *s = &(daemon_service[i]);
557 int namelen = strlen(s->name);
558 if (!strncmp("git-", line, 4) &&
559 !strncmp(s->name, line + 4, namelen) &&
49ba83fb 560 line[namelen + 4] == ' ') {
eb30aed7
JL
561 /*
562 * Note: The directory here is probably context sensitive,
563 * and might depend on the actual service being performed.
564 */
565 interp_set_entry(interp_table,
566 INTERP_SLOT_DIR, line + namelen + 5);
49ba83fb
JL
567 return run_service(interp_table, s);
568 }
d819e4e6 569 }
a87e8be2 570
f8ff0c06 571 logerror("Protocol error: '%s'", line);
a87e8be2
LT
572 return -1;
573}
574
66e631de
LT
575
576/*
577 * We count spawned/reaped separately, just to avoid any
578 * races when updating them from signals. The SIGCHLD handler
579 * will only update children_reaped, and the fork logic will
580 * only update children_spawned.
581 *
582 * MAX_CHILDREN should be a power-of-two to make the modulus
583 * operation cheap. It should also be at least twice
584 * the maximum number of connections we will ever allow.
585 */
586#define MAX_CHILDREN 128
587
588static int max_connections = 25;
589
590/* These are updated by the signal handler */
96f1e58f 591static volatile unsigned int children_reaped;
4d8fa916 592static pid_t dead_child[MAX_CHILDREN];
66e631de
LT
593
594/* These are updated by the main loop */
96f1e58f
DR
595static unsigned int children_spawned;
596static unsigned int children_deleted;
66e631de 597
4d8fa916 598static struct child {
66e631de 599 pid_t pid;
7fa09084 600 int addrlen;
df076bdb 601 struct sockaddr_storage address;
66e631de
LT
602} live_child[MAX_CHILDREN];
603
7fa09084 604static void add_child(int idx, pid_t pid, struct sockaddr *addr, int addrlen)
66e631de
LT
605{
606 live_child[idx].pid = pid;
607 live_child[idx].addrlen = addrlen;
df076bdb 608 memcpy(&live_child[idx].address, addr, addrlen);
66e631de
LT
609}
610
611/*
612 * Walk from "deleted" to "spawned", and remove child "pid".
613 *
614 * We move everything up by one, since the new "deleted" will
615 * be one higher.
616 */
617static void remove_child(pid_t pid, unsigned deleted, unsigned spawned)
618{
619 struct child n;
620
621 deleted %= MAX_CHILDREN;
622 spawned %= MAX_CHILDREN;
623 if (live_child[deleted].pid == pid) {
624 live_child[deleted].pid = -1;
625 return;
626 }
627 n = live_child[deleted];
628 for (;;) {
629 struct child m;
630 deleted = (deleted + 1) % MAX_CHILDREN;
631 if (deleted == spawned)
632 die("could not find dead child %d\n", pid);
633 m = live_child[deleted];
634 live_child[deleted] = n;
635 if (m.pid == pid)
636 return;
637 n = m;
638 }
639}
640
641/*
642 * This gets called if the number of connections grows
643 * past "max_connections".
644 *
645 * We _should_ start off by searching for connections
646 * from the same IP, and if there is some address wth
647 * multiple connections, we should kill that first.
648 *
649 * As it is, we just "randomly" kill 25% of the connections,
650 * and our pseudo-random generator sucks too. I have no
651 * shame.
652 *
653 * Really, this is just a place-holder for a _real_ algorithm.
654 */
02d57da4 655static void kill_some_children(int signo, unsigned start, unsigned stop)
66e631de
LT
656{
657 start %= MAX_CHILDREN;
658 stop %= MAX_CHILDREN;
659 while (start != stop) {
660 if (!(start & 3))
02d57da4 661 kill(live_child[start].pid, signo);
66e631de
LT
662 start = (start + 1) % MAX_CHILDREN;
663 }
664}
665
02d57da4 666static void check_max_connections(void)
a87e8be2 667{
02d57da4 668 for (;;) {
eaa94919 669 int active;
66e631de 670 unsigned spawned, reaped, deleted;
eaa94919 671
66e631de 672 spawned = children_spawned;
66e631de
LT
673 reaped = children_reaped;
674 deleted = children_deleted;
675
676 while (deleted < reaped) {
677 pid_t pid = dead_child[deleted % MAX_CHILDREN];
678 remove_child(pid, deleted, spawned);
679 deleted++;
680 }
681 children_deleted = deleted;
682
683 active = spawned - deleted;
02d57da4
LT
684 if (active <= max_connections)
685 break;
66e631de 686
02d57da4
LT
687 /* Kill some unstarted connections with SIGTERM */
688 kill_some_children(SIGTERM, deleted, spawned);
689 if (active <= max_connections << 1)
690 break;
691
692 /* If the SIGTERM thing isn't helping use SIGKILL */
693 kill_some_children(SIGKILL, deleted, spawned);
694 sleep(1);
695 }
696}
697
7fa09084 698static void handle(int incoming, struct sockaddr *addr, int addrlen)
02d57da4
LT
699{
700 pid_t pid = fork();
701
702 if (pid) {
703 unsigned idx;
704
705 close(incoming);
706 if (pid < 0)
707 return;
708
709 idx = children_spawned % MAX_CHILDREN;
710 children_spawned++;
711 add_child(idx, pid, addr, addrlen);
66e631de 712
02d57da4 713 check_max_connections();
a87e8be2
LT
714 return;
715 }
716
717 dup2(incoming, 0);
718 dup2(incoming, 1);
719 close(incoming);
f8ff0c06 720
5b276ee4 721 exit(execute(addr));
a87e8be2
LT
722}
723
eaa94919
LT
724static void child_handler(int signo)
725{
726 for (;;) {
9048fe1c
PB
727 int status;
728 pid_t pid = waitpid(-1, &status, WNOHANG);
66e631de
LT
729
730 if (pid > 0) {
731 unsigned reaped = children_reaped;
732 dead_child[reaped % MAX_CHILDREN] = pid;
733 children_reaped = reaped + 1;
f8ff0c06 734 /* XXX: Custom logging, since we don't wanna getpid() */
9048fe1c 735 if (verbose) {
554fe20d 736 const char *dead = "";
9048fe1c
PB
737 if (!WIFEXITED(status) || WEXITSTATUS(status) > 0)
738 dead = " (with error)";
739 if (log_syslog)
740 syslog(LOG_INFO, "[%d] Disconnected%s", pid, dead);
741 else
742 fprintf(stderr, "[%d] Disconnected%s\n", pid, dead);
743 }
eaa94919
LT
744 continue;
745 }
746 break;
747 }
748}
749
1955fabf
MW
750static int set_reuse_addr(int sockfd)
751{
752 int on = 1;
753
754 if (!reuseaddr)
755 return 0;
756 return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
757 &on, sizeof(on));
758}
759
6573faff
PA
760#ifndef NO_IPV6
761
dd467629 762static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
a87e8be2 763{
df076bdb
YH
764 int socknum = 0, *socklist = NULL;
765 int maxfd = -1;
df076bdb 766 char pbuf[NI_MAXSERV];
6573faff
PA
767 struct addrinfo hints, *ai0, *ai;
768 int gai;
df076bdb 769
dd467629 770 sprintf(pbuf, "%d", listen_port);
df076bdb
YH
771 memset(&hints, 0, sizeof(hints));
772 hints.ai_family = AF_UNSPEC;
773 hints.ai_socktype = SOCK_STREAM;
774 hints.ai_protocol = IPPROTO_TCP;
775 hints.ai_flags = AI_PASSIVE;
776
dd467629 777 gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
df076bdb
YH
778 if (gai)
779 die("getaddrinfo() failed: %s\n", gai_strerror(gai));
780
df076bdb
YH
781 for (ai = ai0; ai; ai = ai->ai_next) {
782 int sockfd;
df076bdb
YH
783
784 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
785 if (sockfd < 0)
786 continue;
787 if (sockfd >= FD_SETSIZE) {
788 error("too large socket descriptor.");
789 close(sockfd);
790 continue;
791 }
792
793#ifdef IPV6_V6ONLY
794 if (ai->ai_family == AF_INET6) {
795 int on = 1;
796 setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
797 &on, sizeof(on));
798 /* Note: error is not fatal */
799 }
800#endif
801
1955fabf
MW
802 if (set_reuse_addr(sockfd)) {
803 close(sockfd);
0032d548 804 continue;
1955fabf
MW
805 }
806
df076bdb
YH
807 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
808 close(sockfd);
809 continue; /* not fatal */
810 }
811 if (listen(sockfd, 5) < 0) {
812 close(sockfd);
813 continue; /* not fatal */
814 }
815
83572c1a 816 socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
df076bdb
YH
817 socklist[socknum++] = sockfd;
818
df076bdb
YH
819 if (maxfd < sockfd)
820 maxfd = sockfd;
821 }
822
823 freeaddrinfo(ai0);
824
6573faff
PA
825 *socklist_p = socklist;
826 return socknum;
827}
828
829#else /* NO_IPV6 */
830
100690b6 831static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
6573faff
PA
832{
833 struct sockaddr_in sin;
834 int sockfd;
835
dd467629
JL
836 memset(&sin, 0, sizeof sin);
837 sin.sin_family = AF_INET;
838 sin.sin_port = htons(listen_port);
839
840 if (listen_addr) {
841 /* Well, host better be an IP address here. */
842 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
843 return 0;
844 } else {
845 sin.sin_addr.s_addr = htonl(INADDR_ANY);
846 }
847
6573faff
PA
848 sockfd = socket(AF_INET, SOCK_STREAM, 0);
849 if (sockfd < 0)
850 return 0;
851
1955fabf
MW
852 if (set_reuse_addr(sockfd)) {
853 close(sockfd);
854 return 0;
855 }
856
6573faff
PA
857 if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
858 close(sockfd);
859 return 0;
860 }
a87e8be2 861
f35230fb
PS
862 if (listen(sockfd, 5) < 0) {
863 close(sockfd);
864 return 0;
865 }
866
1b4713fb 867 *socklist_p = xmalloc(sizeof(int));
6573faff 868 **socklist_p = sockfd;
f35230fb 869 return 1;
6573faff
PA
870}
871
872#endif
873
874static int service_loop(int socknum, int *socklist)
875{
876 struct pollfd *pfd;
877 int i;
878
1b4713fb 879 pfd = xcalloc(socknum, sizeof(struct pollfd));
6573faff
PA
880
881 for (i = 0; i < socknum; i++) {
882 pfd[i].fd = socklist[i];
883 pfd[i].events = POLLIN;
884 }
9220282a
PA
885
886 signal(SIGCHLD, child_handler);
a87e8be2
LT
887
888 for (;;) {
df076bdb 889 int i;
6573faff 890
7872e055 891 if (poll(pfd, socknum, -1) < 0) {
1eef0b33 892 if (errno != EINTR) {
6573faff 893 error("poll failed, resuming: %s",
1eef0b33
JH
894 strerror(errno));
895 sleep(1);
896 }
df076bdb
YH
897 continue;
898 }
899
900 for (i = 0; i < socknum; i++) {
6573faff 901 if (pfd[i].revents & POLLIN) {
df076bdb 902 struct sockaddr_storage ss;
7626e49e 903 unsigned int sslen = sizeof(ss);
6573faff 904 int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
df076bdb
YH
905 if (incoming < 0) {
906 switch (errno) {
907 case EAGAIN:
908 case EINTR:
909 case ECONNABORTED:
910 continue;
911 default:
912 die("accept returned %s", strerror(errno));
913 }
914 }
915 handle(incoming, (struct sockaddr *)&ss, sslen);
a87e8be2
LT
916 }
917 }
a87e8be2
LT
918 }
919}
920
258e93a1
ML
921/* if any standard file descriptor is missing open it to /dev/null */
922static void sanitize_stdfds(void)
923{
924 int fd = open("/dev/null", O_RDWR, 0);
925 while (fd != -1 && fd < 2)
926 fd = dup(fd);
927 if (fd == -1)
928 die("open /dev/null or dup failed: %s", strerror(errno));
929 if (fd > 2)
930 close(fd);
931}
932
a5262768
ML
933static void daemonize(void)
934{
935 switch (fork()) {
936 case 0:
937 break;
938 case -1:
939 die("fork failed: %s", strerror(errno));
940 default:
941 exit(0);
942 }
943 if (setsid() == -1)
944 die("setsid failed: %s", strerror(errno));
945 close(0);
946 close(1);
947 close(2);
948 sanitize_stdfds();
949}
950
45ed5d7f
ML
951static void store_pid(const char *path)
952{
953 FILE *f = fopen(path, "w");
954 if (!f)
955 die("cannot open pid file %s: %s", path, strerror(errno));
956 fprintf(f, "%d\n", getpid());
957 fclose(f);
958}
959
dd467629 960static int serve(char *listen_addr, int listen_port, struct passwd *pass, gid_t gid)
6573faff
PA
961{
962 int socknum, *socklist;
4ae22d96 963
dd467629 964 socknum = socksetup(listen_addr, listen_port, &socklist);
6573faff 965 if (socknum == 0)
dd467629
JL
966 die("unable to allocate any listen sockets on host %s port %u",
967 listen_addr, listen_port);
4ae22d96 968
678dac6b
TS
969 if (pass && gid &&
970 (initgroups(pass->pw_name, gid) || setgid (gid) ||
971 setuid(pass->pw_uid)))
972 die("cannot drop privileges");
973
6573faff 974 return service_loop(socknum, socklist);
4ae22d96 975}
6573faff 976
a87e8be2
LT
977int main(int argc, char **argv)
978{
dd467629
JL
979 int listen_port = 0;
980 char *listen_addr = NULL;
e64e1b79 981 int inetd_mode = 0;
678dac6b 982 const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
a5262768 983 int detach = 0;
678dac6b
TS
984 struct passwd *pass = NULL;
985 struct group *group;
986 gid_t gid = 0;
a87e8be2
LT
987 int i;
988
f0b7367c
JH
989 /* Without this we cannot rely on waitpid() to tell
990 * what happened to our children.
991 */
992 signal(SIGCHLD, SIG_DFL);
993
a87e8be2
LT
994 for (i = 1; i < argc; i++) {
995 char *arg = argv[i];
996
dd467629
JL
997 if (!strncmp(arg, "--listen=", 9)) {
998 char *p = arg + 9;
999 char *ph = listen_addr = xmalloc(strlen(arg + 9) + 1);
1000 while (*p)
1001 *ph++ = tolower(*p++);
1002 *ph = 0;
1003 continue;
1004 }
a87e8be2
LT
1005 if (!strncmp(arg, "--port=", 7)) {
1006 char *end;
1007 unsigned long n;
1008 n = strtoul(arg+7, &end, 0);
1009 if (arg[7] && !*end) {
dd467629 1010 listen_port = n;
a87e8be2
LT
1011 continue;
1012 }
1013 }
e64e1b79
LT
1014 if (!strcmp(arg, "--inetd")) {
1015 inetd_mode = 1;
a8883288 1016 log_syslog = 1;
e64e1b79
LT
1017 continue;
1018 }
f8ff0c06
PB
1019 if (!strcmp(arg, "--verbose")) {
1020 verbose = 1;
1021 continue;
1022 }
9048fe1c
PB
1023 if (!strcmp(arg, "--syslog")) {
1024 log_syslog = 1;
9048fe1c
PB
1025 continue;
1026 }
4ae95682
PA
1027 if (!strcmp(arg, "--export-all")) {
1028 export_all_trees = 1;
1029 continue;
1030 }
960deccb
PA
1031 if (!strncmp(arg, "--timeout=", 10)) {
1032 timeout = atoi(arg+10);
a8883288 1033 continue;
960deccb 1034 }
54e31a20 1035 if (!strncmp(arg, "--init-timeout=", 15)) {
960deccb 1036 init_timeout = atoi(arg+15);
a8883288 1037 continue;
960deccb 1038 }
4dbd1352
AE
1039 if (!strcmp(arg, "--strict-paths")) {
1040 strict_paths = 1;
1041 continue;
1042 }
b21c31c9
PB
1043 if (!strncmp(arg, "--base-path=", 12)) {
1044 base_path = arg+12;
1045 continue;
1046 }
49ba83fb
JL
1047 if (!strncmp(arg, "--interpolated-path=", 20)) {
1048 interpolated_path = arg+20;
1049 continue;
1050 }
1955fabf
MW
1051 if (!strcmp(arg, "--reuseaddr")) {
1052 reuseaddr = 1;
1053 continue;
1054 }
603968d2
JH
1055 if (!strcmp(arg, "--user-path")) {
1056 user_path = "";
1057 continue;
1058 }
1059 if (!strncmp(arg, "--user-path=", 12)) {
1060 user_path = arg + 12;
1061 continue;
1062 }
45ed5d7f
ML
1063 if (!strncmp(arg, "--pid-file=", 11)) {
1064 pid_file = arg + 11;
1065 continue;
1066 }
a5262768
ML
1067 if (!strcmp(arg, "--detach")) {
1068 detach = 1;
1069 log_syslog = 1;
1070 continue;
1071 }
678dac6b
TS
1072 if (!strncmp(arg, "--user=", 7)) {
1073 user_name = arg + 7;
1074 continue;
1075 }
1076 if (!strncmp(arg, "--group=", 8)) {
1077 group_name = arg + 8;
1078 continue;
1079 }
d819e4e6
JH
1080 if (!strncmp(arg, "--enable=", 9)) {
1081 enable_service(arg + 9, 1);
1082 continue;
1083 }
1084 if (!strncmp(arg, "--disable=", 10)) {
1085 enable_service(arg + 10, 0);
1086 continue;
1087 }
74c0cc21
JH
1088 if (!strncmp(arg, "--allow-override=", 17)) {
1089 make_service_overridable(arg + 17, 1);
d819e4e6
JH
1090 continue;
1091 }
74c0cc21
JH
1092 if (!strncmp(arg, "--forbid-override=", 18)) {
1093 make_service_overridable(arg + 18, 0);
d819e4e6
JH
1094 continue;
1095 }
4ae95682
PA
1096 if (!strcmp(arg, "--")) {
1097 ok_paths = &argv[i+1];
1098 break;
1099 } else if (arg[0] != '-') {
1100 ok_paths = &argv[i];
1101 break;
1102 }
e64e1b79 1103
a87e8be2
LT
1104 usage(daemon_usage);
1105 }
1106
678dac6b
TS
1107 if (inetd_mode && (group_name || user_name))
1108 die("--user and --group are incompatible with --inetd");
1109
dd467629
JL
1110 if (inetd_mode && (listen_port || listen_addr))
1111 die("--listen= and --port= are incompatible with --inetd");
1112 else if (listen_port == 0)
1113 listen_port = DEFAULT_GIT_PORT;
1114
678dac6b
TS
1115 if (group_name && !user_name)
1116 die("--group supplied without --user");
1117
1118 if (user_name) {
1119 pass = getpwnam(user_name);
1120 if (!pass)
1121 die("user not found - %s", user_name);
1122
1123 if (!group_name)
1124 gid = pass->pw_gid;
1125 else {
1126 group = getgrnam(group_name);
1127 if (!group)
1128 die("group not found - %s", group_name);
1129
1130 gid = group->gr_gid;
1131 }
1132 }
1133
ad8b4f56 1134 if (log_syslog) {
a8883288 1135 openlog("git-daemon", 0, LOG_DAEMON);
ad8b4f56 1136 set_die_routine(daemon_die);
4dbd1352
AE
1137 }
1138
ad8b4f56
ML
1139 if (strict_paths && (!ok_paths || !*ok_paths))
1140 die("option --strict-paths requires a whitelist");
1141
7c3693f1 1142 if (inetd_mode) {
5b276ee4
DW
1143 struct sockaddr_storage ss;
1144 struct sockaddr *peer = (struct sockaddr *)&ss;
1145 socklen_t slen = sizeof(ss);
1146
ba0012c3 1147 freopen("/dev/null", "w", stderr);
5b276ee4
DW
1148
1149 if (getpeername(0, peer, &slen))
1150 peer = NULL;
1151
1152 return execute(peer);
7c3693f1 1153 }
bce8230d 1154
a5262768
ML
1155 if (detach)
1156 daemonize();
1157 else
1158 sanitize_stdfds();
258e93a1 1159
45ed5d7f
ML
1160 if (pid_file)
1161 store_pid(pid_file);
1162
dd467629 1163 return serve(listen_addr, listen_port, pass, gid);
a87e8be2 1164}