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