t6023-merge-file: Work around non-portable sed usage
[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
415e7b87
PW
12#ifndef NI_MAXSERV
13#define NI_MAXSERV 32
14#endif
15
9048fe1c 16static int log_syslog;
f8ff0c06 17static int verbose;
1955fabf 18static int reuseaddr;
f8ff0c06 19
960deccb 20static const char daemon_usage[] =
1b1dd23f 21"git daemon [--verbose] [--syslog] [--export-all]\n"
3bd62c21
SB
22" [--timeout=n] [--init-timeout=n] [--max-connections=n]\n"
23" [--strict-paths] [--base-path=path] [--base-path-relaxed]\n"
73a7a656 24" [--user-path | --user-path=path]\n"
49ba83fb 25" [--interpolated-path=path]\n"
678dac6b 26" [--reuseaddr] [--detach] [--pid-file=file]\n"
d9edcbd6 27" [--[enable|disable|allow-override|forbid-override]=service]\n"
dd467629
JL
28" [--inetd | [--listen=host_or_ipaddr] [--port=n]\n"
29" [--user=user [--group=group]]\n"
30" [directory...]";
4ae95682
PA
31
32/* List of acceptable pathname prefixes */
96f1e58f
DR
33static char **ok_paths;
34static int strict_paths;
4ae95682
PA
35
36/* If this is set, git-daemon-export-ok is not required */
96f1e58f 37static int export_all_trees;
f8ff0c06 38
b21c31c9 39/* Take all paths relative to this one if non-NULL */
96f1e58f 40static char *base_path;
49ba83fb 41static char *interpolated_path;
73a7a656 42static int base_path_relaxed;
49ba83fb
JL
43
44/* Flag indicating client sent extra args. */
45static int saw_extended_args;
b21c31c9 46
603968d2
JH
47/* If defined, ~user notation is allowed and the string is inserted
48 * after ~user/. E.g. a request to git://host/~alice/frotz would
49 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
50 */
96f1e58f 51static const char *user_path;
603968d2 52
960deccb 53/* Timeout, and initial timeout */
96f1e58f
DR
54static unsigned int timeout;
55static unsigned int init_timeout;
f8ff0c06 56
49ba83fb
JL
57/*
58 * Static table for now. Ugh.
59 * Feel free to make dynamic as needed.
60 */
61#define INTERP_SLOT_HOST (0)
dd467629
JL
62#define INTERP_SLOT_CANON_HOST (1)
63#define INTERP_SLOT_IP (2)
64#define INTERP_SLOT_PORT (3)
65#define INTERP_SLOT_DIR (4)
66#define INTERP_SLOT_PERCENT (5)
49ba83fb
JL
67
68static struct interp interp_table[] = {
69 { "%H", 0},
dd467629
JL
70 { "%CH", 0},
71 { "%IP", 0},
72 { "%P", 0},
49ba83fb 73 { "%D", 0},
eb30aed7 74 { "%%", 0},
49ba83fb
JL
75};
76
77
9048fe1c 78static void logreport(int priority, const char *err, va_list params)
f8ff0c06 79{
9048fe1c 80 if (log_syslog) {
6a992e9e
SB
81 char buf[1024];
82 vsnprintf(buf, sizeof(buf), err, params);
9048fe1c 83 syslog(priority, "%s", buf);
460c2010
JH
84 } else {
85 /*
86 * Since stderr is set to linebuffered mode, the
6a992e9e
SB
87 * logging of different processes will not overlap
88 */
85e72830 89 fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
6a992e9e
SB
90 vfprintf(stderr, err, params);
91 fputc('\n', stderr);
92 }
f8ff0c06
PB
93}
94
cdda4745 95static void logerror(const char *err, ...)
f8ff0c06
PB
96{
97 va_list params;
98 va_start(params, err);
9048fe1c 99 logreport(LOG_ERR, err, params);
f8ff0c06
PB
100 va_end(params);
101}
102
cdda4745 103static void loginfo(const char *err, ...)
f8ff0c06
PB
104{
105 va_list params;
106 if (!verbose)
107 return;
108 va_start(params, err);
9048fe1c 109 logreport(LOG_INFO, err, params);
f8ff0c06
PB
110 va_end(params);
111}
a87e8be2 112
ad8b4f56
ML
113static void NORETURN daemon_die(const char *err, va_list params)
114{
115 logreport(LOG_ERR, err, params);
116 exit(1);
117}
118
d79374c7
JH
119static int avoid_alias(char *p)
120{
121 int sl, ndot;
122
a6080a0a 123 /*
d79374c7
JH
124 * This resurrects the belts and suspenders paranoia check by HPA
125 * done in <435560F7.4080006@zytor.com> thread, now enter_repo()
126 * does not do getcwd() based path canonicalizations.
127 *
128 * sl becomes true immediately after seeing '/' and continues to
129 * be true as long as dots continue after that without intervening
130 * non-dot character.
131 */
132 if (!p || (*p != '/' && *p != '~'))
133 return -1;
134 sl = 1; ndot = 0;
135 p++;
136
137 while (1) {
138 char ch = *p++;
139 if (sl) {
140 if (ch == '.')
141 ndot++;
142 else if (ch == '/') {
143 if (ndot < 3)
144 /* reject //, /./ and /../ */
145 return -1;
146 ndot = 0;
147 }
148 else if (ch == 0) {
149 if (0 < ndot && ndot < 3)
150 /* reject /.$ and /..$ */
151 return -1;
152 return 0;
153 }
154 else
155 sl = ndot = 0;
156 }
157 else if (ch == 0)
158 return 0;
159 else if (ch == '/') {
160 sl = 1;
161 ndot = 0;
162 }
163 }
164}
165
49ba83fb 166static char *path_ok(struct interp *itable)
4ae95682 167{
603968d2 168 static char rpath[PATH_MAX];
49ba83fb 169 static char interp_path[PATH_MAX];
73a7a656 170 int retried_path = 0;
d79374c7 171 char *path;
49ba83fb
JL
172 char *dir;
173
174 dir = itable[INTERP_SLOT_DIR].value;
d79374c7
JH
175
176 if (avoid_alias(dir)) {
177 logerror("'%s': aliased", dir);
178 return NULL;
179 }
180
603968d2
JH
181 if (*dir == '~') {
182 if (!user_path) {
183 logerror("'%s': User-path not allowed", dir);
184 return NULL;
185 }
186 if (*user_path) {
187 /* Got either "~alice" or "~alice/foo";
188 * rewrite them to "~alice/%s" or
189 * "~alice/%s/foo".
190 */
191 int namlen, restlen = strlen(dir);
192 char *slash = strchr(dir, '/');
193 if (!slash)
194 slash = dir + restlen;
195 namlen = slash - dir;
196 restlen -= namlen;
197 loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
198 snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
199 namlen, dir, user_path, restlen, slash);
200 dir = rpath;
201 }
202 }
49ba83fb
JL
203 else if (interpolated_path && saw_extended_args) {
204 if (*dir != '/') {
205 /* Allow only absolute */
206 logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
207 return NULL;
208 }
209
210 interpolate(interp_path, PATH_MAX, interpolated_path,
211 interp_table, ARRAY_SIZE(interp_table));
212 loginfo("Interpolated dir '%s'", interp_path);
213
214 dir = interp_path;
215 }
603968d2
JH
216 else if (base_path) {
217 if (*dir != '/') {
218 /* Allow only absolute */
1fda3d55 219 logerror("'%s': Non-absolute path denied (base-path active)", dir);
b21c31c9
PB
220 return NULL;
221 }
49ba83fb
JL
222 snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
223 dir = rpath;
b21c31c9
PB
224 }
225
73a7a656
JA
226 do {
227 path = enter_repo(dir, strict_paths);
228 if (path)
229 break;
230
231 /*
232 * if we fail and base_path_relaxed is enabled, try without
233 * prefixing the base path
234 */
235 if (base_path && base_path_relaxed && !retried_path) {
236 dir = itable[INTERP_SLOT_DIR].value;
237 retried_path = 1;
238 continue;
239 }
240 break;
241 } while (1);
3e04c62d 242
4dbd1352
AE
243 if (!path) {
244 logerror("'%s': unable to chdir or not a git archive", dir);
245 return NULL;
4ae95682
PA
246 }
247
248 if ( ok_paths && *ok_paths ) {
ce335fe0 249 char **pp;
4dbd1352 250 int pathlen = strlen(path);
4ae95682 251
ce335fe0 252 /* The validation is done on the paths after enter_repo
a6080a0a 253 * appends optional {.git,.git/.git} and friends, but
d79374c7
JH
254 * it does not use getcwd(). So if your /pub is
255 * a symlink to /mnt/pub, you can whitelist /pub and
256 * do not have to say /mnt/pub.
257 * Do not say /pub/.
ce335fe0 258 */
4ae95682
PA
259 for ( pp = ok_paths ; *pp ; pp++ ) {
260 int len = strlen(*pp);
ce335fe0
JH
261 if (len <= pathlen &&
262 !memcmp(*pp, path, len) &&
263 (path[len] == '\0' ||
264 (!strict_paths && path[len] == '/')))
265 return path;
4ae95682 266 }
4dbd1352
AE
267 }
268 else {
269 /* be backwards compatible */
270 if (!strict_paths)
271 return path;
4ae95682
PA
272 }
273
4dbd1352
AE
274 logerror("'%s': not in whitelist", path);
275 return NULL; /* Fallthrough. Deny by default */
4ae95682 276}
a87e8be2 277
d819e4e6
JH
278typedef int (*daemon_service_fn)(void);
279struct daemon_service {
280 const char *name;
281 const char *config_name;
282 daemon_service_fn fn;
283 int enabled;
284 int overridable;
285};
286
287static struct daemon_service *service_looking_at;
288static int service_enabled;
289
ef90d6d4 290static int git_daemon_config(const char *var, const char *value, void *cb)
d819e4e6 291{
cc44c765 292 if (!prefixcmp(var, "daemon.") &&
d819e4e6
JH
293 !strcmp(var + 7, service_looking_at->config_name)) {
294 service_enabled = git_config_bool(var, value);
295 return 0;
296 }
297
298 /* we are not interested in parsing any other configuration here */
299 return 0;
300}
301
49ba83fb 302static int run_service(struct interp *itable, struct daemon_service *service)
a87e8be2 303{
4dbd1352 304 const char *path;
d819e4e6
JH
305 int enabled = service->enabled;
306
49ba83fb
JL
307 loginfo("Request %s for '%s'",
308 service->name,
309 itable[INTERP_SLOT_DIR].value);
4dbd1352 310
d819e4e6
JH
311 if (!enabled && !service->overridable) {
312 logerror("'%s': service not enabled.", service->name);
313 errno = EACCES;
314 return -1;
315 }
4ae95682 316
49ba83fb 317 if (!(path = path_ok(itable)))
a87e8be2 318 return -1;
47888f0f 319
a87e8be2
LT
320 /*
321 * Security on the cheap.
322 *
a935c397 323 * We want a readable HEAD, usable "objects" directory, and
a87e8be2
LT
324 * a "git-daemon-export-ok" flag that says that the other side
325 * is ok with us doing this.
4dbd1352
AE
326 *
327 * path_ok() uses enter_repo() and does whitelist checking.
328 * We only need to make sure the repository is exported.
a87e8be2 329 */
4dbd1352 330
3e04c62d 331 if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
4dbd1352 332 logerror("'%s': repository not exported.", path);
3e04c62d
PA
333 errno = EACCES;
334 return -1;
335 }
336
d819e4e6
JH
337 if (service->overridable) {
338 service_looking_at = service;
339 service_enabled = -1;
ef90d6d4 340 git_config(git_daemon_config, NULL);
d819e4e6
JH
341 if (0 <= service_enabled)
342 enabled = service_enabled;
343 }
344 if (!enabled) {
345 logerror("'%s': service not enabled for '%s'",
346 service->name, path);
347 errno = EACCES;
348 return -1;
349 }
350
02d57da4
LT
351 /*
352 * We'll ignore SIGTERM from now on, we have a
353 * good client.
354 */
355 signal(SIGTERM, SIG_IGN);
356
d819e4e6
JH
357 return service->fn();
358}
359
360static int upload_pack(void)
361{
362 /* Timeout as string */
363 char timeout_buf[64];
364
960deccb
PA
365 snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
366
a87e8be2 367 /* git-upload-pack only ever reads stuff, so this is safe */
77cb17e9 368 execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL);
a87e8be2
LT
369 return -1;
370}
371
39345a21
FBH
372static int upload_archive(void)
373{
374 execl_git_cmd("upload-archive", ".", NULL);
375 return -1;
376}
377
4b3b1e1e
LT
378static int receive_pack(void)
379{
380 execl_git_cmd("receive-pack", ".", NULL);
381 return -1;
382}
383
d819e4e6 384static struct daemon_service daemon_service[] = {
39345a21 385 { "upload-archive", "uploadarch", upload_archive, 0, 1 },
d819e4e6 386 { "upload-pack", "uploadpack", upload_pack, 1, 1 },
4b3b1e1e 387 { "receive-pack", "receivepack", receive_pack, 0, 1 },
d819e4e6
JH
388};
389
f3fa1838
JH
390static void enable_service(const char *name, int ena)
391{
d819e4e6
JH
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].enabled = ena;
396 return;
397 }
398 }
399 die("No such service %s", name);
400}
401
f3fa1838
JH
402static void make_service_overridable(const char *name, int ena)
403{
d819e4e6
JH
404 int i;
405 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
406 if (!strcmp(daemon_service[i].name, name)) {
407 daemon_service[i].overridable = ena;
408 return;
409 }
410 }
411 die("No such service %s", name);
412}
413
eb30aed7
JL
414/*
415 * Separate the "extra args" information as supplied by the client connection.
3dff5379 416 * Any resulting data is squirreled away in the given interpolation table.
eb30aed7
JL
417 */
418static void parse_extra_args(struct interp *table, char *extra_args, int buflen)
49ba83fb
JL
419{
420 char *val;
421 int vallen;
422 char *end = extra_args + buflen;
423
424 while (extra_args < end && *extra_args) {
425 saw_extended_args = 1;
426 if (strncasecmp("host=", extra_args, 5) == 0) {
427 val = extra_args + 5;
428 vallen = strlen(val) + 1;
429 if (*val) {
eb30aed7
JL
430 /* Split <host>:<port> at colon. */
431 char *host = val;
432 char *port = strrchr(host, ':');
dd467629
JL
433 if (port) {
434 *port = 0;
435 port++;
eb30aed7 436 interp_set_entry(table, INTERP_SLOT_PORT, port);
dd467629 437 }
eb30aed7 438 interp_set_entry(table, INTERP_SLOT_HOST, host);
49ba83fb 439 }
eb30aed7 440
49ba83fb
JL
441 /* On to the next one */
442 extra_args = val + vallen;
443 }
444 }
445}
446
52fae7de 447static void fill_in_extra_table_entries(struct interp *itable)
dd467629
JL
448{
449 char *hp;
dd467629
JL
450
451 /*
452 * Replace literal host with lowercase-ized hostname.
453 */
454 hp = interp_table[INTERP_SLOT_HOST].value;
83543a24
JH
455 if (!hp)
456 return;
dd467629
JL
457 for ( ; *hp; hp++)
458 *hp = tolower(*hp);
459
460 /*
461 * Locate canonical hostname and its IP address.
462 */
463#ifndef NO_IPV6
464 {
465 struct addrinfo hints;
466 struct addrinfo *ai, *ai0;
467 int gai;
468 static char addrbuf[HOST_NAME_MAX + 1];
469
470 memset(&hints, 0, sizeof(hints));
471 hints.ai_flags = AI_CANONNAME;
472
473 gai = getaddrinfo(interp_table[INTERP_SLOT_HOST].value, 0, &hints, &ai0);
474 if (!gai) {
475 for (ai = ai0; ai; ai = ai->ai_next) {
476 struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
477
dd467629
JL
478 inet_ntop(AF_INET, &sin_addr->sin_addr,
479 addrbuf, sizeof(addrbuf));
eb30aed7
JL
480 interp_set_entry(interp_table,
481 INTERP_SLOT_CANON_HOST, ai->ai_canonname);
482 interp_set_entry(interp_table,
483 INTERP_SLOT_IP, addrbuf);
dd467629
JL
484 break;
485 }
486 freeaddrinfo(ai0);
487 }
488 }
489#else
490 {
491 struct hostent *hent;
492 struct sockaddr_in sa;
493 char **ap;
494 static char addrbuf[HOST_NAME_MAX + 1];
495
496 hent = gethostbyname(interp_table[INTERP_SLOT_HOST].value);
dd467629
JL
497
498 ap = hent->h_addr_list;
499 memset(&sa, 0, sizeof sa);
500 sa.sin_family = hent->h_addrtype;
501 sa.sin_port = htons(0);
502 memcpy(&sa.sin_addr, *ap, hent->h_length);
503
504 inet_ntop(hent->h_addrtype, &sa.sin_addr,
505 addrbuf, sizeof(addrbuf));
eb30aed7
JL
506
507 interp_set_entry(interp_table, INTERP_SLOT_CANON_HOST, hent->h_name);
508 interp_set_entry(interp_table, INTERP_SLOT_IP, addrbuf);
dd467629
JL
509 }
510#endif
dd467629
JL
511}
512
513
5b276ee4 514static int execute(struct sockaddr *addr)
a87e8be2 515{
7d80694a 516 static char line[1000];
d819e4e6 517 int pktlen, len, i;
7d80694a 518
5b276ee4
DW
519 if (addr) {
520 char addrbuf[256] = "";
521 int port = -1;
522
523 if (addr->sa_family == AF_INET) {
524 struct sockaddr_in *sin_addr = (void *) addr;
525 inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
c67359be 526 port = ntohs(sin_addr->sin_port);
5b276ee4
DW
527#ifndef NO_IPV6
528 } else if (addr && addr->sa_family == AF_INET6) {
529 struct sockaddr_in6 *sin6_addr = (void *) addr;
530
531 char *buf = addrbuf;
532 *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
533 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
534 strcat(buf, "]");
535
c67359be 536 port = ntohs(sin6_addr->sin6_port);
5b276ee4
DW
537#endif
538 }
539 loginfo("Connection from %s:%d", addrbuf, port);
540 }
541
960deccb 542 alarm(init_timeout ? init_timeout : timeout);
5ad312be 543 pktlen = packet_read_line(0, line, sizeof(line));
960deccb 544 alarm(0);
7d80694a 545
5ad312be
JL
546 len = strlen(line);
547 if (pktlen != len)
548 loginfo("Extended attributes (%d bytes) exist <%.*s>",
549 (int) pktlen - len,
550 (int) pktlen - len, line + len + 1);
83543a24 551 if (len && line[len-1] == '\n') {
7d80694a 552 line[--len] = 0;
83543a24
JH
553 pktlen--;
554 }
7d80694a 555
eb30aed7
JL
556 /*
557 * Initialize the path interpolation table for this connection.
558 */
559 interp_clear_table(interp_table, ARRAY_SIZE(interp_table));
560 interp_set_entry(interp_table, INTERP_SLOT_PERCENT, "%");
561
dd467629 562 if (len != pktlen) {
eb30aed7 563 parse_extra_args(interp_table, line + len + 1, pktlen - len - 1);
dd467629
JL
564 fill_in_extra_table_entries(interp_table);
565 }
49ba83fb 566
d819e4e6
JH
567 for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
568 struct daemon_service *s = &(daemon_service[i]);
569 int namelen = strlen(s->name);
599065a3 570 if (!prefixcmp(line, "git-") &&
d819e4e6 571 !strncmp(s->name, line + 4, namelen) &&
49ba83fb 572 line[namelen + 4] == ' ') {
eb30aed7
JL
573 /*
574 * Note: The directory here is probably context sensitive,
575 * and might depend on the actual service being performed.
576 */
577 interp_set_entry(interp_table,
578 INTERP_SLOT_DIR, line + namelen + 5);
49ba83fb
JL
579 return run_service(interp_table, s);
580 }
d819e4e6 581 }
a87e8be2 582
f8ff0c06 583 logerror("Protocol error: '%s'", line);
a87e8be2
LT
584 return -1;
585}
586
3bd62c21 587static int max_connections = 32;
66e631de 588
3bd62c21 589static unsigned int live_children;
66e631de 590
4d8fa916 591static struct child {
3bd62c21 592 struct child *next;
66e631de 593 pid_t pid;
df076bdb 594 struct sockaddr_storage address;
3bd62c21 595} *firstborn;
66e631de 596
3bd62c21 597static void add_child(pid_t pid, struct sockaddr *addr, int addrlen)
66e631de 598{
460c2010
JH
599 struct child *newborn, **cradle;
600
601 /*
602 * This must be xcalloc() -- we'll compare the whole sockaddr_storage
603 * but individual address may be shorter.
604 */
605 newborn = xcalloc(1, sizeof(*newborn));
606 live_children++;
607 newborn->pid = pid;
608 memcpy(&newborn->address, addr, addrlen);
609 for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
610 if (!memcmp(&(*cradle)->address, &newborn->address,
611 sizeof(newborn->address)))
612 break;
613 newborn->next = *cradle;
614 *cradle = newborn;
66e631de
LT
615}
616
3bd62c21 617static void remove_child(pid_t pid)
66e631de 618{
3bd62c21 619 struct child **cradle, *blanket;
66e631de 620
3bd62c21
SB
621 for (cradle = &firstborn; (blanket = *cradle); cradle = &blanket->next)
622 if (blanket->pid == pid) {
623 *cradle = blanket->next;
624 live_children--;
625 free(blanket);
626 break;
627 }
66e631de
LT
628}
629
630/*
631 * This gets called if the number of connections grows
632 * past "max_connections".
633 *
3bd62c21 634 * We kill the newest connection from a duplicate IP.
66e631de 635 */
3bd62c21 636static void kill_some_child(void)
66e631de 637{
460c2010 638 const struct child *blanket, *next;
66e631de 639
460c2010
JH
640 if (!(blanket = firstborn))
641 return;
695605b5 642
460c2010
JH
643 for (; (next = blanket->next); blanket = next)
644 if (!memcmp(&blanket->address, &next->address,
645 sizeof(next->address))) {
646 kill(blanket->pid, SIGTERM);
647 break;
648 }
a5a9126b
JS
649}
650
3bd62c21 651static void check_dead_children(void)
a87e8be2 652{
3bd62c21
SB
653 int status;
654 pid_t pid;
02d57da4 655
460c2010 656 while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
3bd62c21
SB
657 const char *dead = "";
658 remove_child(pid);
460c2010 659 if (!WIFEXITED(status) || (WEXITSTATUS(status) > 0))
3bd62c21 660 dead = " (with error)";
85e72830 661 loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
02d57da4
LT
662 }
663}
664
7fa09084 665static void handle(int incoming, struct sockaddr *addr, int addrlen)
02d57da4 666{
3bd62c21 667 pid_t pid;
02d57da4 668
3bd62c21
SB
669 if (max_connections && live_children >= max_connections) {
670 kill_some_child();
460c2010 671 sleep(1); /* give it some time to die */
3bd62c21
SB
672 check_dead_children();
673 if (live_children >= max_connections) {
674 close(incoming);
675 logerror("Too many children, dropping connection");
676 return;
677 }
678 }
02d57da4 679
3bd62c21 680 if ((pid = fork())) {
02d57da4 681 close(incoming);
3bd62c21
SB
682 if (pid < 0) {
683 logerror("Couldn't fork %s", strerror(errno));
02d57da4 684 return;
3bd62c21 685 }
02d57da4 686
3bd62c21 687 add_child(pid, addr, addrlen);
a87e8be2
LT
688 return;
689 }
690
691 dup2(incoming, 0);
692 dup2(incoming, 1);
693 close(incoming);
f8ff0c06 694
5b276ee4 695 exit(execute(addr));
a87e8be2
LT
696}
697
eaa94919
LT
698static void child_handler(int signo)
699{
460c2010
JH
700 /*
701 * Otherwise empty handler because systemcalls will get interrupted
695605b5
SB
702 * upon signal receipt
703 * SysV needs the handler to be rearmed
704 */
bd7b371e 705 signal(SIGCHLD, child_handler);
eaa94919
LT
706}
707
1955fabf
MW
708static int set_reuse_addr(int sockfd)
709{
710 int on = 1;
711
712 if (!reuseaddr)
713 return 0;
714 return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
715 &on, sizeof(on));
716}
717
6573faff
PA
718#ifndef NO_IPV6
719
dd467629 720static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
a87e8be2 721{
df076bdb
YH
722 int socknum = 0, *socklist = NULL;
723 int maxfd = -1;
df076bdb 724 char pbuf[NI_MAXSERV];
6573faff
PA
725 struct addrinfo hints, *ai0, *ai;
726 int gai;
20276889 727 long flags;
df076bdb 728
dd467629 729 sprintf(pbuf, "%d", listen_port);
df076bdb
YH
730 memset(&hints, 0, sizeof(hints));
731 hints.ai_family = AF_UNSPEC;
732 hints.ai_socktype = SOCK_STREAM;
733 hints.ai_protocol = IPPROTO_TCP;
734 hints.ai_flags = AI_PASSIVE;
735
dd467629 736 gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
df076bdb
YH
737 if (gai)
738 die("getaddrinfo() failed: %s\n", gai_strerror(gai));
739
df076bdb
YH
740 for (ai = ai0; ai; ai = ai->ai_next) {
741 int sockfd;
df076bdb
YH
742
743 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
744 if (sockfd < 0)
745 continue;
746 if (sockfd >= FD_SETSIZE) {
df0daf8a 747 logerror("Socket descriptor too large");
df076bdb
YH
748 close(sockfd);
749 continue;
750 }
751
752#ifdef IPV6_V6ONLY
753 if (ai->ai_family == AF_INET6) {
754 int on = 1;
755 setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
756 &on, sizeof(on));
757 /* Note: error is not fatal */
758 }
759#endif
760
1955fabf
MW
761 if (set_reuse_addr(sockfd)) {
762 close(sockfd);
0032d548 763 continue;
1955fabf
MW
764 }
765
df076bdb
YH
766 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
767 close(sockfd);
768 continue; /* not fatal */
769 }
770 if (listen(sockfd, 5) < 0) {
771 close(sockfd);
772 continue; /* not fatal */
773 }
774
20276889
AJ
775 flags = fcntl(sockfd, F_GETFD, 0);
776 if (flags >= 0)
777 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
778
83572c1a 779 socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
df076bdb
YH
780 socklist[socknum++] = sockfd;
781
df076bdb
YH
782 if (maxfd < sockfd)
783 maxfd = sockfd;
784 }
785
786 freeaddrinfo(ai0);
787
6573faff
PA
788 *socklist_p = socklist;
789 return socknum;
790}
791
792#else /* NO_IPV6 */
793
100690b6 794static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
6573faff
PA
795{
796 struct sockaddr_in sin;
797 int sockfd;
20276889 798 long flags;
6573faff 799
dd467629
JL
800 memset(&sin, 0, sizeof sin);
801 sin.sin_family = AF_INET;
802 sin.sin_port = htons(listen_port);
803
804 if (listen_addr) {
805 /* Well, host better be an IP address here. */
806 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
807 return 0;
808 } else {
809 sin.sin_addr.s_addr = htonl(INADDR_ANY);
810 }
811
6573faff
PA
812 sockfd = socket(AF_INET, SOCK_STREAM, 0);
813 if (sockfd < 0)
814 return 0;
815
1955fabf
MW
816 if (set_reuse_addr(sockfd)) {
817 close(sockfd);
818 return 0;
819 }
820
6573faff
PA
821 if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
822 close(sockfd);
823 return 0;
824 }
a87e8be2 825
f35230fb
PS
826 if (listen(sockfd, 5) < 0) {
827 close(sockfd);
828 return 0;
829 }
830
20276889
AJ
831 flags = fcntl(sockfd, F_GETFD, 0);
832 if (flags >= 0)
833 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
834
1b4713fb 835 *socklist_p = xmalloc(sizeof(int));
6573faff 836 **socklist_p = sockfd;
f35230fb 837 return 1;
6573faff
PA
838}
839
840#endif
841
842static int service_loop(int socknum, int *socklist)
843{
844 struct pollfd *pfd;
845 int i;
846
695605b5 847 pfd = xcalloc(socknum, sizeof(struct pollfd));
6573faff
PA
848
849 for (i = 0; i < socknum; i++) {
850 pfd[i].fd = socklist[i];
851 pfd[i].events = POLLIN;
852 }
9220282a
PA
853
854 signal(SIGCHLD, child_handler);
a87e8be2
LT
855
856 for (;;) {
df076bdb 857 int i;
6573faff 858
695605b5
SB
859 check_dead_children();
860
861 if (poll(pfd, socknum, -1) < 0) {
1eef0b33 862 if (errno != EINTR) {
df0daf8a 863 logerror("Poll failed, resuming: %s",
1eef0b33
JH
864 strerror(errno));
865 sleep(1);
866 }
df076bdb
YH
867 continue;
868 }
869
870 for (i = 0; i < socknum; i++) {
6573faff 871 if (pfd[i].revents & POLLIN) {
df076bdb 872 struct sockaddr_storage ss;
7626e49e 873 unsigned int sslen = sizeof(ss);
6573faff 874 int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
df076bdb
YH
875 if (incoming < 0) {
876 switch (errno) {
877 case EAGAIN:
878 case EINTR:
879 case ECONNABORTED:
880 continue;
881 default:
882 die("accept returned %s", strerror(errno));
883 }
884 }
885 handle(incoming, (struct sockaddr *)&ss, sslen);
a87e8be2
LT
886 }
887 }
a87e8be2
LT
888 }
889}
890
258e93a1
ML
891/* if any standard file descriptor is missing open it to /dev/null */
892static void sanitize_stdfds(void)
893{
894 int fd = open("/dev/null", O_RDWR, 0);
895 while (fd != -1 && fd < 2)
896 fd = dup(fd);
897 if (fd == -1)
898 die("open /dev/null or dup failed: %s", strerror(errno));
899 if (fd > 2)
900 close(fd);
901}
902
a5262768
ML
903static void daemonize(void)
904{
905 switch (fork()) {
906 case 0:
907 break;
908 case -1:
909 die("fork failed: %s", strerror(errno));
910 default:
911 exit(0);
912 }
913 if (setsid() == -1)
914 die("setsid failed: %s", strerror(errno));
915 close(0);
916 close(1);
917 close(2);
918 sanitize_stdfds();
919}
920
45ed5d7f
ML
921static void store_pid(const char *path)
922{
923 FILE *f = fopen(path, "w");
924 if (!f)
925 die("cannot open pid file %s: %s", path, strerror(errno));
85e72830 926 if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0)
bc4e7d03 927 die("failed to write pid file %s: %s", path, strerror(errno));
45ed5d7f
ML
928}
929
dd467629 930static int serve(char *listen_addr, int listen_port, struct passwd *pass, gid_t gid)
6573faff
PA
931{
932 int socknum, *socklist;
4ae22d96 933
dd467629 934 socknum = socksetup(listen_addr, listen_port, &socklist);
6573faff 935 if (socknum == 0)
dd467629
JL
936 die("unable to allocate any listen sockets on host %s port %u",
937 listen_addr, listen_port);
4ae22d96 938
678dac6b
TS
939 if (pass && gid &&
940 (initgroups(pass->pw_name, gid) || setgid (gid) ||
941 setuid(pass->pw_uid)))
942 die("cannot drop privileges");
943
6573faff 944 return service_loop(socknum, socklist);
4ae22d96 945}
6573faff 946
a87e8be2
LT
947int main(int argc, char **argv)
948{
dd467629
JL
949 int listen_port = 0;
950 char *listen_addr = NULL;
e64e1b79 951 int inetd_mode = 0;
678dac6b 952 const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
a5262768 953 int detach = 0;
678dac6b
TS
954 struct passwd *pass = NULL;
955 struct group *group;
956 gid_t gid = 0;
a87e8be2
LT
957 int i;
958
959 for (i = 1; i < argc; i++) {
960 char *arg = argv[i];
961
cc44c765 962 if (!prefixcmp(arg, "--listen=")) {
dd467629
JL
963 char *p = arg + 9;
964 char *ph = listen_addr = xmalloc(strlen(arg + 9) + 1);
965 while (*p)
966 *ph++ = tolower(*p++);
967 *ph = 0;
968 continue;
969 }
cc44c765 970 if (!prefixcmp(arg, "--port=")) {
a87e8be2
LT
971 char *end;
972 unsigned long n;
973 n = strtoul(arg+7, &end, 0);
974 if (arg[7] && !*end) {
dd467629 975 listen_port = n;
a87e8be2
LT
976 continue;
977 }
978 }
e64e1b79
LT
979 if (!strcmp(arg, "--inetd")) {
980 inetd_mode = 1;
a8883288 981 log_syslog = 1;
e64e1b79
LT
982 continue;
983 }
f8ff0c06
PB
984 if (!strcmp(arg, "--verbose")) {
985 verbose = 1;
986 continue;
987 }
9048fe1c
PB
988 if (!strcmp(arg, "--syslog")) {
989 log_syslog = 1;
9048fe1c
PB
990 continue;
991 }
4ae95682
PA
992 if (!strcmp(arg, "--export-all")) {
993 export_all_trees = 1;
994 continue;
995 }
cc44c765 996 if (!prefixcmp(arg, "--timeout=")) {
960deccb 997 timeout = atoi(arg+10);
a8883288 998 continue;
960deccb 999 }
cc44c765 1000 if (!prefixcmp(arg, "--init-timeout=")) {
960deccb 1001 init_timeout = atoi(arg+15);
a8883288 1002 continue;
960deccb 1003 }
3bd62c21
SB
1004 if (!prefixcmp(arg, "--max-connections=")) {
1005 max_connections = atoi(arg+18);
1006 if (max_connections < 0)
1007 max_connections = 0; /* unlimited */
1008 continue;
1009 }
4dbd1352
AE
1010 if (!strcmp(arg, "--strict-paths")) {
1011 strict_paths = 1;
1012 continue;
1013 }
cc44c765 1014 if (!prefixcmp(arg, "--base-path=")) {
b21c31c9
PB
1015 base_path = arg+12;
1016 continue;
1017 }
73a7a656
JA
1018 if (!strcmp(arg, "--base-path-relaxed")) {
1019 base_path_relaxed = 1;
1020 continue;
1021 }
cc44c765 1022 if (!prefixcmp(arg, "--interpolated-path=")) {
49ba83fb
JL
1023 interpolated_path = arg+20;
1024 continue;
1025 }
1955fabf
MW
1026 if (!strcmp(arg, "--reuseaddr")) {
1027 reuseaddr = 1;
1028 continue;
1029 }
603968d2
JH
1030 if (!strcmp(arg, "--user-path")) {
1031 user_path = "";
1032 continue;
1033 }
cc44c765 1034 if (!prefixcmp(arg, "--user-path=")) {
603968d2
JH
1035 user_path = arg + 12;
1036 continue;
1037 }
cc44c765 1038 if (!prefixcmp(arg, "--pid-file=")) {
45ed5d7f
ML
1039 pid_file = arg + 11;
1040 continue;
1041 }
a5262768
ML
1042 if (!strcmp(arg, "--detach")) {
1043 detach = 1;
1044 log_syslog = 1;
1045 continue;
1046 }
cc44c765 1047 if (!prefixcmp(arg, "--user=")) {
678dac6b
TS
1048 user_name = arg + 7;
1049 continue;
1050 }
cc44c765 1051 if (!prefixcmp(arg, "--group=")) {
678dac6b
TS
1052 group_name = arg + 8;
1053 continue;
1054 }
cc44c765 1055 if (!prefixcmp(arg, "--enable=")) {
d819e4e6
JH
1056 enable_service(arg + 9, 1);
1057 continue;
1058 }
cc44c765 1059 if (!prefixcmp(arg, "--disable=")) {
d819e4e6
JH
1060 enable_service(arg + 10, 0);
1061 continue;
1062 }
cc44c765 1063 if (!prefixcmp(arg, "--allow-override=")) {
74c0cc21 1064 make_service_overridable(arg + 17, 1);
d819e4e6
JH
1065 continue;
1066 }
cc44c765 1067 if (!prefixcmp(arg, "--forbid-override=")) {
74c0cc21 1068 make_service_overridable(arg + 18, 0);
d819e4e6
JH
1069 continue;
1070 }
4ae95682
PA
1071 if (!strcmp(arg, "--")) {
1072 ok_paths = &argv[i+1];
1073 break;
1074 } else if (arg[0] != '-') {
1075 ok_paths = &argv[i];
1076 break;
1077 }
e64e1b79 1078
a87e8be2
LT
1079 usage(daemon_usage);
1080 }
1081
22665bba 1082 if (log_syslog) {
6a992e9e 1083 openlog("git-daemon", LOG_PID, LOG_DAEMON);
22665bba 1084 set_die_routine(daemon_die);
460c2010 1085 } else
6a992e9e 1086 setlinebuf(stderr); /* avoid splitting a message in the middle */
22665bba 1087
678dac6b
TS
1088 if (inetd_mode && (group_name || user_name))
1089 die("--user and --group are incompatible with --inetd");
1090
dd467629
JL
1091 if (inetd_mode && (listen_port || listen_addr))
1092 die("--listen= and --port= are incompatible with --inetd");
1093 else if (listen_port == 0)
1094 listen_port = DEFAULT_GIT_PORT;
1095
678dac6b
TS
1096 if (group_name && !user_name)
1097 die("--group supplied without --user");
1098
1099 if (user_name) {
1100 pass = getpwnam(user_name);
1101 if (!pass)
1102 die("user not found - %s", user_name);
1103
1104 if (!group_name)
1105 gid = pass->pw_gid;
1106 else {
1107 group = getgrnam(group_name);
1108 if (!group)
1109 die("group not found - %s", group_name);
1110
1111 gid = group->gr_gid;
1112 }
1113 }
1114
ad8b4f56
ML
1115 if (strict_paths && (!ok_paths || !*ok_paths))
1116 die("option --strict-paths requires a whitelist");
1117
20632071
JS
1118 if (base_path) {
1119 struct stat st;
1120
1121 if (stat(base_path, &st) || !S_ISDIR(st.st_mode))
1122 die("base-path '%s' does not exist or "
1123 "is not a directory", base_path);
1124 }
1125
7c3693f1 1126 if (inetd_mode) {
5b276ee4
DW
1127 struct sockaddr_storage ss;
1128 struct sockaddr *peer = (struct sockaddr *)&ss;
1129 socklen_t slen = sizeof(ss);
1130
ba0012c3 1131 freopen("/dev/null", "w", stderr);
5b276ee4
DW
1132
1133 if (getpeername(0, peer, &slen))
1134 peer = NULL;
1135
1136 return execute(peer);
7c3693f1 1137 }
bce8230d 1138
6a992e9e 1139 if (detach) {
a5262768 1140 daemonize();
6a992e9e
SB
1141 loginfo("Ready to rumble");
1142 }
a5262768
ML
1143 else
1144 sanitize_stdfds();
258e93a1 1145
45ed5d7f
ML
1146 if (pid_file)
1147 store_pid(pid_file);
1148
dd467629 1149 return serve(listen_addr, listen_port, pass, gid);
a87e8be2 1150}