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1 | #include "cache.h" | |
2 | #include "pkt-line.h" | |
3 | #include "exec_cmd.h" | |
4 | #include "run-command.h" | |
5 | #include "strbuf.h" | |
6 | #include "string-list.h" | |
7 | ||
8 | #ifndef HOST_NAME_MAX | |
9 | #define HOST_NAME_MAX 256 | |
10 | #endif | |
11 | ||
12 | #ifndef NI_MAXSERV | |
13 | #define NI_MAXSERV 32 | |
14 | #endif | |
15 | ||
16 | static int log_syslog; | |
17 | static int verbose; | |
18 | static int reuseaddr; | |
19 | ||
20 | static const char daemon_usage[] = | |
21 | "git daemon [--verbose] [--syslog] [--export-all]\n" | |
22 | " [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n" | |
23 | " [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n" | |
24 | " [--user-path | --user-path=<path>]\n" | |
25 | " [--interpolated-path=<path>]\n" | |
26 | " [--reuseaddr] [--detach] [--pid-file=<file>]\n" | |
27 | " [--(enable|disable|allow-override|forbid-override)=<service>]\n" | |
28 | " [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n" | |
29 | " [--user=<user> [--group=<group>]]\n" | |
30 | " [<directory>...]"; | |
31 | ||
32 | /* List of acceptable pathname prefixes */ | |
33 | static char **ok_paths; | |
34 | static int strict_paths; | |
35 | ||
36 | /* If this is set, git-daemon-export-ok is not required */ | |
37 | static int export_all_trees; | |
38 | ||
39 | /* Take all paths relative to this one if non-NULL */ | |
40 | static char *base_path; | |
41 | static char *interpolated_path; | |
42 | static int base_path_relaxed; | |
43 | ||
44 | /* Flag indicating client sent extra args. */ | |
45 | static int saw_extended_args; | |
46 | ||
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 | */ | |
51 | static const char *user_path; | |
52 | ||
53 | /* Timeout, and initial timeout */ | |
54 | static unsigned int timeout; | |
55 | static unsigned int init_timeout; | |
56 | ||
57 | static char *hostname; | |
58 | static char *canon_hostname; | |
59 | static char *ip_address; | |
60 | static char *tcp_port; | |
61 | ||
62 | static void logreport(int priority, const char *err, va_list params) | |
63 | { | |
64 | if (log_syslog) { | |
65 | char buf[1024]; | |
66 | vsnprintf(buf, sizeof(buf), err, params); | |
67 | syslog(priority, "%s", buf); | |
68 | } else { | |
69 | /* | |
70 | * Since stderr is set to linebuffered mode, the | |
71 | * logging of different processes will not overlap | |
72 | */ | |
73 | fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid()); | |
74 | vfprintf(stderr, err, params); | |
75 | fputc('\n', stderr); | |
76 | } | |
77 | } | |
78 | ||
79 | __attribute__((format (printf, 1, 2))) | |
80 | static void logerror(const char *err, ...) | |
81 | { | |
82 | va_list params; | |
83 | va_start(params, err); | |
84 | logreport(LOG_ERR, err, params); | |
85 | va_end(params); | |
86 | } | |
87 | ||
88 | __attribute__((format (printf, 1, 2))) | |
89 | static void loginfo(const char *err, ...) | |
90 | { | |
91 | va_list params; | |
92 | if (!verbose) | |
93 | return; | |
94 | va_start(params, err); | |
95 | logreport(LOG_INFO, err, params); | |
96 | va_end(params); | |
97 | } | |
98 | ||
99 | static void NORETURN daemon_die(const char *err, va_list params) | |
100 | { | |
101 | logreport(LOG_ERR, err, params); | |
102 | exit(1); | |
103 | } | |
104 | ||
105 | static char *path_ok(char *directory) | |
106 | { | |
107 | static char rpath[PATH_MAX]; | |
108 | static char interp_path[PATH_MAX]; | |
109 | char *path; | |
110 | char *dir; | |
111 | ||
112 | dir = directory; | |
113 | ||
114 | if (daemon_avoid_alias(dir)) { | |
115 | logerror("'%s': aliased", dir); | |
116 | return NULL; | |
117 | } | |
118 | ||
119 | if (*dir == '~') { | |
120 | if (!user_path) { | |
121 | logerror("'%s': User-path not allowed", dir); | |
122 | return NULL; | |
123 | } | |
124 | if (*user_path) { | |
125 | /* Got either "~alice" or "~alice/foo"; | |
126 | * rewrite them to "~alice/%s" or | |
127 | * "~alice/%s/foo". | |
128 | */ | |
129 | int namlen, restlen = strlen(dir); | |
130 | char *slash = strchr(dir, '/'); | |
131 | if (!slash) | |
132 | slash = dir + restlen; | |
133 | namlen = slash - dir; | |
134 | restlen -= namlen; | |
135 | loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash); | |
136 | snprintf(rpath, PATH_MAX, "%.*s/%s%.*s", | |
137 | namlen, dir, user_path, restlen, slash); | |
138 | dir = rpath; | |
139 | } | |
140 | } | |
141 | else if (interpolated_path && saw_extended_args) { | |
142 | struct strbuf expanded_path = STRBUF_INIT; | |
143 | struct strbuf_expand_dict_entry dict[6]; | |
144 | ||
145 | dict[0].placeholder = "H"; dict[0].value = hostname; | |
146 | dict[1].placeholder = "CH"; dict[1].value = canon_hostname; | |
147 | dict[2].placeholder = "IP"; dict[2].value = ip_address; | |
148 | dict[3].placeholder = "P"; dict[3].value = tcp_port; | |
149 | dict[4].placeholder = "D"; dict[4].value = directory; | |
150 | dict[5].placeholder = NULL; dict[5].value = NULL; | |
151 | if (*dir != '/') { | |
152 | /* Allow only absolute */ | |
153 | logerror("'%s': Non-absolute path denied (interpolated-path active)", dir); | |
154 | return NULL; | |
155 | } | |
156 | ||
157 | strbuf_expand(&expanded_path, interpolated_path, | |
158 | strbuf_expand_dict_cb, &dict); | |
159 | strlcpy(interp_path, expanded_path.buf, PATH_MAX); | |
160 | strbuf_release(&expanded_path); | |
161 | loginfo("Interpolated dir '%s'", interp_path); | |
162 | ||
163 | dir = interp_path; | |
164 | } | |
165 | else if (base_path) { | |
166 | if (*dir != '/') { | |
167 | /* Allow only absolute */ | |
168 | logerror("'%s': Non-absolute path denied (base-path active)", dir); | |
169 | return NULL; | |
170 | } | |
171 | snprintf(rpath, PATH_MAX, "%s%s", base_path, dir); | |
172 | dir = rpath; | |
173 | } | |
174 | ||
175 | path = enter_repo(dir, strict_paths); | |
176 | if (!path && base_path && base_path_relaxed) { | |
177 | /* | |
178 | * if we fail and base_path_relaxed is enabled, try without | |
179 | * prefixing the base path | |
180 | */ | |
181 | dir = directory; | |
182 | path = enter_repo(dir, strict_paths); | |
183 | } | |
184 | ||
185 | if (!path) { | |
186 | logerror("'%s' does not appear to be a git repository", dir); | |
187 | return NULL; | |
188 | } | |
189 | ||
190 | if ( ok_paths && *ok_paths ) { | |
191 | char **pp; | |
192 | int pathlen = strlen(path); | |
193 | ||
194 | /* The validation is done on the paths after enter_repo | |
195 | * appends optional {.git,.git/.git} and friends, but | |
196 | * it does not use getcwd(). So if your /pub is | |
197 | * a symlink to /mnt/pub, you can whitelist /pub and | |
198 | * do not have to say /mnt/pub. | |
199 | * Do not say /pub/. | |
200 | */ | |
201 | for ( pp = ok_paths ; *pp ; pp++ ) { | |
202 | int len = strlen(*pp); | |
203 | if (len <= pathlen && | |
204 | !memcmp(*pp, path, len) && | |
205 | (path[len] == '\0' || | |
206 | (!strict_paths && path[len] == '/'))) | |
207 | return path; | |
208 | } | |
209 | } | |
210 | else { | |
211 | /* be backwards compatible */ | |
212 | if (!strict_paths) | |
213 | return path; | |
214 | } | |
215 | ||
216 | logerror("'%s': not in whitelist", path); | |
217 | return NULL; /* Fallthrough. Deny by default */ | |
218 | } | |
219 | ||
220 | typedef int (*daemon_service_fn)(void); | |
221 | struct daemon_service { | |
222 | const char *name; | |
223 | const char *config_name; | |
224 | daemon_service_fn fn; | |
225 | int enabled; | |
226 | int overridable; | |
227 | }; | |
228 | ||
229 | static struct daemon_service *service_looking_at; | |
230 | static int service_enabled; | |
231 | ||
232 | static int git_daemon_config(const char *var, const char *value, void *cb) | |
233 | { | |
234 | if (!prefixcmp(var, "daemon.") && | |
235 | !strcmp(var + 7, service_looking_at->config_name)) { | |
236 | service_enabled = git_config_bool(var, value); | |
237 | return 0; | |
238 | } | |
239 | ||
240 | /* we are not interested in parsing any other configuration here */ | |
241 | return 0; | |
242 | } | |
243 | ||
244 | static int run_service(char *dir, struct daemon_service *service) | |
245 | { | |
246 | const char *path; | |
247 | int enabled = service->enabled; | |
248 | ||
249 | loginfo("Request %s for '%s'", service->name, dir); | |
250 | ||
251 | if (!enabled && !service->overridable) { | |
252 | logerror("'%s': service not enabled.", service->name); | |
253 | errno = EACCES; | |
254 | return -1; | |
255 | } | |
256 | ||
257 | if (!(path = path_ok(dir))) | |
258 | return -1; | |
259 | ||
260 | /* | |
261 | * Security on the cheap. | |
262 | * | |
263 | * We want a readable HEAD, usable "objects" directory, and | |
264 | * a "git-daemon-export-ok" flag that says that the other side | |
265 | * is ok with us doing this. | |
266 | * | |
267 | * path_ok() uses enter_repo() and does whitelist checking. | |
268 | * We only need to make sure the repository is exported. | |
269 | */ | |
270 | ||
271 | if (!export_all_trees && access("git-daemon-export-ok", F_OK)) { | |
272 | logerror("'%s': repository not exported.", path); | |
273 | errno = EACCES; | |
274 | return -1; | |
275 | } | |
276 | ||
277 | if (service->overridable) { | |
278 | service_looking_at = service; | |
279 | service_enabled = -1; | |
280 | git_config(git_daemon_config, NULL); | |
281 | if (0 <= service_enabled) | |
282 | enabled = service_enabled; | |
283 | } | |
284 | if (!enabled) { | |
285 | logerror("'%s': service not enabled for '%s'", | |
286 | service->name, path); | |
287 | errno = EACCES; | |
288 | return -1; | |
289 | } | |
290 | ||
291 | /* | |
292 | * We'll ignore SIGTERM from now on, we have a | |
293 | * good client. | |
294 | */ | |
295 | signal(SIGTERM, SIG_IGN); | |
296 | ||
297 | return service->fn(); | |
298 | } | |
299 | ||
300 | static void copy_to_log(int fd) | |
301 | { | |
302 | struct strbuf line = STRBUF_INIT; | |
303 | FILE *fp; | |
304 | ||
305 | fp = fdopen(fd, "r"); | |
306 | if (fp == NULL) { | |
307 | logerror("fdopen of error channel failed"); | |
308 | close(fd); | |
309 | return; | |
310 | } | |
311 | ||
312 | while (strbuf_getline(&line, fp, '\n') != EOF) { | |
313 | logerror("%s", line.buf); | |
314 | strbuf_setlen(&line, 0); | |
315 | } | |
316 | ||
317 | strbuf_release(&line); | |
318 | fclose(fp); | |
319 | } | |
320 | ||
321 | static int run_service_command(const char **argv) | |
322 | { | |
323 | struct child_process cld; | |
324 | ||
325 | memset(&cld, 0, sizeof(cld)); | |
326 | cld.argv = argv; | |
327 | cld.git_cmd = 1; | |
328 | cld.err = -1; | |
329 | if (start_command(&cld)) | |
330 | return -1; | |
331 | ||
332 | close(0); | |
333 | close(1); | |
334 | ||
335 | copy_to_log(cld.err); | |
336 | ||
337 | return finish_command(&cld); | |
338 | } | |
339 | ||
340 | static int upload_pack(void) | |
341 | { | |
342 | /* Timeout as string */ | |
343 | char timeout_buf[64]; | |
344 | const char *argv[] = { "upload-pack", "--strict", NULL, ".", NULL }; | |
345 | ||
346 | argv[2] = timeout_buf; | |
347 | ||
348 | snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout); | |
349 | return run_service_command(argv); | |
350 | } | |
351 | ||
352 | static int upload_archive(void) | |
353 | { | |
354 | static const char *argv[] = { "upload-archive", ".", NULL }; | |
355 | return run_service_command(argv); | |
356 | } | |
357 | ||
358 | static int receive_pack(void) | |
359 | { | |
360 | static const char *argv[] = { "receive-pack", ".", NULL }; | |
361 | return run_service_command(argv); | |
362 | } | |
363 | ||
364 | static struct daemon_service daemon_service[] = { | |
365 | { "upload-archive", "uploadarch", upload_archive, 0, 1 }, | |
366 | { "upload-pack", "uploadpack", upload_pack, 1, 1 }, | |
367 | { "receive-pack", "receivepack", receive_pack, 0, 1 }, | |
368 | }; | |
369 | ||
370 | static void enable_service(const char *name, int ena) | |
371 | { | |
372 | int i; | |
373 | for (i = 0; i < ARRAY_SIZE(daemon_service); i++) { | |
374 | if (!strcmp(daemon_service[i].name, name)) { | |
375 | daemon_service[i].enabled = ena; | |
376 | return; | |
377 | } | |
378 | } | |
379 | die("No such service %s", name); | |
380 | } | |
381 | ||
382 | static void make_service_overridable(const char *name, int ena) | |
383 | { | |
384 | int i; | |
385 | for (i = 0; i < ARRAY_SIZE(daemon_service); i++) { | |
386 | if (!strcmp(daemon_service[i].name, name)) { | |
387 | daemon_service[i].overridable = ena; | |
388 | return; | |
389 | } | |
390 | } | |
391 | die("No such service %s", name); | |
392 | } | |
393 | ||
394 | static char *xstrdup_tolower(const char *str) | |
395 | { | |
396 | char *p, *dup = xstrdup(str); | |
397 | for (p = dup; *p; p++) | |
398 | *p = tolower(*p); | |
399 | return dup; | |
400 | } | |
401 | ||
402 | static void parse_host_and_port(char *hostport, char **host, | |
403 | char **port) | |
404 | { | |
405 | if (*hostport == '[') { | |
406 | char *end; | |
407 | ||
408 | end = strchr(hostport, ']'); | |
409 | if (!end) | |
410 | die("Invalid request ('[' without ']')"); | |
411 | *end = '\0'; | |
412 | *host = hostport + 1; | |
413 | if (!end[1]) | |
414 | *port = NULL; | |
415 | else if (end[1] == ':') | |
416 | *port = end + 2; | |
417 | else | |
418 | die("Garbage after end of host part"); | |
419 | } else { | |
420 | *host = hostport; | |
421 | *port = strrchr(hostport, ':'); | |
422 | if (*port) { | |
423 | **port = '\0'; | |
424 | ++*port; | |
425 | } | |
426 | } | |
427 | } | |
428 | ||
429 | /* | |
430 | * Read the host as supplied by the client connection. | |
431 | */ | |
432 | static void parse_host_arg(char *extra_args, int buflen) | |
433 | { | |
434 | char *val; | |
435 | int vallen; | |
436 | char *end = extra_args + buflen; | |
437 | ||
438 | if (extra_args < end && *extra_args) { | |
439 | saw_extended_args = 1; | |
440 | if (strncasecmp("host=", extra_args, 5) == 0) { | |
441 | val = extra_args + 5; | |
442 | vallen = strlen(val) + 1; | |
443 | if (*val) { | |
444 | /* Split <host>:<port> at colon. */ | |
445 | char *host; | |
446 | char *port; | |
447 | parse_host_and_port(val, &host, &port); | |
448 | if (port) { | |
449 | free(tcp_port); | |
450 | tcp_port = xstrdup(port); | |
451 | } | |
452 | free(hostname); | |
453 | hostname = xstrdup_tolower(host); | |
454 | } | |
455 | ||
456 | /* On to the next one */ | |
457 | extra_args = val + vallen; | |
458 | } | |
459 | if (extra_args < end && *extra_args) | |
460 | die("Invalid request"); | |
461 | } | |
462 | ||
463 | /* | |
464 | * Locate canonical hostname and its IP address. | |
465 | */ | |
466 | if (hostname) { | |
467 | #ifndef NO_IPV6 | |
468 | struct addrinfo hints; | |
469 | struct addrinfo *ai; | |
470 | int gai; | |
471 | static char addrbuf[HOST_NAME_MAX + 1]; | |
472 | ||
473 | memset(&hints, 0, sizeof(hints)); | |
474 | hints.ai_flags = AI_CANONNAME; | |
475 | ||
476 | gai = getaddrinfo(hostname, NULL, &hints, &ai); | |
477 | if (!gai) { | |
478 | struct sockaddr_in *sin_addr = (void *)ai->ai_addr; | |
479 | ||
480 | inet_ntop(AF_INET, &sin_addr->sin_addr, | |
481 | addrbuf, sizeof(addrbuf)); | |
482 | free(ip_address); | |
483 | ip_address = xstrdup(addrbuf); | |
484 | ||
485 | free(canon_hostname); | |
486 | canon_hostname = xstrdup(ai->ai_canonname ? | |
487 | ai->ai_canonname : ip_address); | |
488 | ||
489 | freeaddrinfo(ai); | |
490 | } | |
491 | #else | |
492 | struct hostent *hent; | |
493 | struct sockaddr_in sa; | |
494 | char **ap; | |
495 | static char addrbuf[HOST_NAME_MAX + 1]; | |
496 | ||
497 | hent = gethostbyname(hostname); | |
498 | ||
499 | ap = hent->h_addr_list; | |
500 | memset(&sa, 0, sizeof sa); | |
501 | sa.sin_family = hent->h_addrtype; | |
502 | sa.sin_port = htons(0); | |
503 | memcpy(&sa.sin_addr, *ap, hent->h_length); | |
504 | ||
505 | inet_ntop(hent->h_addrtype, &sa.sin_addr, | |
506 | addrbuf, sizeof(addrbuf)); | |
507 | ||
508 | free(canon_hostname); | |
509 | canon_hostname = xstrdup(hent->h_name); | |
510 | free(ip_address); | |
511 | ip_address = xstrdup(addrbuf); | |
512 | #endif | |
513 | } | |
514 | } | |
515 | ||
516 | ||
517 | static int execute(struct sockaddr *addr) | |
518 | { | |
519 | static char line[1000]; | |
520 | int pktlen, len, i; | |
521 | ||
522 | if (addr) { | |
523 | char addrbuf[256] = ""; | |
524 | int port = -1; | |
525 | ||
526 | if (addr->sa_family == AF_INET) { | |
527 | struct sockaddr_in *sin_addr = (void *) addr; | |
528 | inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf)); | |
529 | port = ntohs(sin_addr->sin_port); | |
530 | #ifndef NO_IPV6 | |
531 | } else if (addr && addr->sa_family == AF_INET6) { | |
532 | struct sockaddr_in6 *sin6_addr = (void *) addr; | |
533 | ||
534 | char *buf = addrbuf; | |
535 | *buf++ = '['; *buf = '\0'; /* stpcpy() is cool */ | |
536 | inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1); | |
537 | strcat(buf, "]"); | |
538 | ||
539 | port = ntohs(sin6_addr->sin6_port); | |
540 | #endif | |
541 | } | |
542 | loginfo("Connection from %s:%d", addrbuf, port); | |
543 | setenv("REMOTE_ADDR", addrbuf, 1); | |
544 | } | |
545 | else { | |
546 | unsetenv("REMOTE_ADDR"); | |
547 | } | |
548 | ||
549 | alarm(init_timeout ? init_timeout : timeout); | |
550 | pktlen = packet_read_line(0, line, sizeof(line)); | |
551 | alarm(0); | |
552 | ||
553 | len = strlen(line); | |
554 | if (pktlen != len) | |
555 | loginfo("Extended attributes (%d bytes) exist <%.*s>", | |
556 | (int) pktlen - len, | |
557 | (int) pktlen - len, line + len + 1); | |
558 | if (len && line[len-1] == '\n') { | |
559 | line[--len] = 0; | |
560 | pktlen--; | |
561 | } | |
562 | ||
563 | free(hostname); | |
564 | free(canon_hostname); | |
565 | free(ip_address); | |
566 | free(tcp_port); | |
567 | hostname = canon_hostname = ip_address = tcp_port = NULL; | |
568 | ||
569 | if (len != pktlen) | |
570 | parse_host_arg(line + len + 1, pktlen - len - 1); | |
571 | ||
572 | for (i = 0; i < ARRAY_SIZE(daemon_service); i++) { | |
573 | struct daemon_service *s = &(daemon_service[i]); | |
574 | int namelen = strlen(s->name); | |
575 | if (!prefixcmp(line, "git-") && | |
576 | !strncmp(s->name, line + 4, namelen) && | |
577 | line[namelen + 4] == ' ') { | |
578 | /* | |
579 | * Note: The directory here is probably context sensitive, | |
580 | * and might depend on the actual service being performed. | |
581 | */ | |
582 | return run_service(line + namelen + 5, s); | |
583 | } | |
584 | } | |
585 | ||
586 | logerror("Protocol error: '%s'", line); | |
587 | return -1; | |
588 | } | |
589 | ||
590 | static int addrcmp(const struct sockaddr_storage *s1, | |
591 | const struct sockaddr_storage *s2) | |
592 | { | |
593 | const struct sockaddr *sa1 = (const struct sockaddr*) s1; | |
594 | const struct sockaddr *sa2 = (const struct sockaddr*) s2; | |
595 | ||
596 | if (sa1->sa_family != sa2->sa_family) | |
597 | return sa1->sa_family - sa2->sa_family; | |
598 | if (sa1->sa_family == AF_INET) | |
599 | return memcmp(&((struct sockaddr_in *)s1)->sin_addr, | |
600 | &((struct sockaddr_in *)s2)->sin_addr, | |
601 | sizeof(struct in_addr)); | |
602 | #ifndef NO_IPV6 | |
603 | if (sa1->sa_family == AF_INET6) | |
604 | return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr, | |
605 | &((struct sockaddr_in6 *)s2)->sin6_addr, | |
606 | sizeof(struct in6_addr)); | |
607 | #endif | |
608 | return 0; | |
609 | } | |
610 | ||
611 | static int max_connections = 32; | |
612 | ||
613 | static unsigned int live_children; | |
614 | ||
615 | static struct child { | |
616 | struct child *next; | |
617 | pid_t pid; | |
618 | struct sockaddr_storage address; | |
619 | } *firstborn; | |
620 | ||
621 | static void add_child(pid_t pid, struct sockaddr *addr, int addrlen) | |
622 | { | |
623 | struct child *newborn, **cradle; | |
624 | ||
625 | newborn = xcalloc(1, sizeof(*newborn)); | |
626 | live_children++; | |
627 | newborn->pid = pid; | |
628 | memcpy(&newborn->address, addr, addrlen); | |
629 | for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next) | |
630 | if (!addrcmp(&(*cradle)->address, &newborn->address)) | |
631 | break; | |
632 | newborn->next = *cradle; | |
633 | *cradle = newborn; | |
634 | } | |
635 | ||
636 | static void remove_child(pid_t pid) | |
637 | { | |
638 | struct child **cradle, *blanket; | |
639 | ||
640 | for (cradle = &firstborn; (blanket = *cradle); cradle = &blanket->next) | |
641 | if (blanket->pid == pid) { | |
642 | *cradle = blanket->next; | |
643 | live_children--; | |
644 | free(blanket); | |
645 | break; | |
646 | } | |
647 | } | |
648 | ||
649 | /* | |
650 | * This gets called if the number of connections grows | |
651 | * past "max_connections". | |
652 | * | |
653 | * We kill the newest connection from a duplicate IP. | |
654 | */ | |
655 | static void kill_some_child(void) | |
656 | { | |
657 | const struct child *blanket, *next; | |
658 | ||
659 | if (!(blanket = firstborn)) | |
660 | return; | |
661 | ||
662 | for (; (next = blanket->next); blanket = next) | |
663 | if (!addrcmp(&blanket->address, &next->address)) { | |
664 | kill(blanket->pid, SIGTERM); | |
665 | break; | |
666 | } | |
667 | } | |
668 | ||
669 | static void check_dead_children(void) | |
670 | { | |
671 | int status; | |
672 | pid_t pid; | |
673 | ||
674 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0) { | |
675 | const char *dead = ""; | |
676 | remove_child(pid); | |
677 | if (!WIFEXITED(status) || (WEXITSTATUS(status) > 0)) | |
678 | dead = " (with error)"; | |
679 | loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead); | |
680 | } | |
681 | } | |
682 | ||
683 | static void handle(int incoming, struct sockaddr *addr, int addrlen) | |
684 | { | |
685 | pid_t pid; | |
686 | ||
687 | if (max_connections && live_children >= max_connections) { | |
688 | kill_some_child(); | |
689 | sleep(1); /* give it some time to die */ | |
690 | check_dead_children(); | |
691 | if (live_children >= max_connections) { | |
692 | close(incoming); | |
693 | logerror("Too many children, dropping connection"); | |
694 | return; | |
695 | } | |
696 | } | |
697 | ||
698 | if ((pid = fork())) { | |
699 | close(incoming); | |
700 | if (pid < 0) { | |
701 | logerror("Couldn't fork %s", strerror(errno)); | |
702 | return; | |
703 | } | |
704 | ||
705 | add_child(pid, addr, addrlen); | |
706 | return; | |
707 | } | |
708 | ||
709 | dup2(incoming, 0); | |
710 | dup2(incoming, 1); | |
711 | close(incoming); | |
712 | ||
713 | exit(execute(addr)); | |
714 | } | |
715 | ||
716 | static void child_handler(int signo) | |
717 | { | |
718 | /* | |
719 | * Otherwise empty handler because systemcalls will get interrupted | |
720 | * upon signal receipt | |
721 | * SysV needs the handler to be rearmed | |
722 | */ | |
723 | signal(SIGCHLD, child_handler); | |
724 | } | |
725 | ||
726 | static int set_reuse_addr(int sockfd) | |
727 | { | |
728 | int on = 1; | |
729 | ||
730 | if (!reuseaddr) | |
731 | return 0; | |
732 | return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, | |
733 | &on, sizeof(on)); | |
734 | } | |
735 | ||
736 | struct socketlist { | |
737 | int *list; | |
738 | size_t nr; | |
739 | size_t alloc; | |
740 | }; | |
741 | ||
742 | #ifndef NO_IPV6 | |
743 | ||
744 | static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist) | |
745 | { | |
746 | int socknum = 0; | |
747 | int maxfd = -1; | |
748 | char pbuf[NI_MAXSERV]; | |
749 | struct addrinfo hints, *ai0, *ai; | |
750 | int gai; | |
751 | long flags; | |
752 | ||
753 | sprintf(pbuf, "%d", listen_port); | |
754 | memset(&hints, 0, sizeof(hints)); | |
755 | hints.ai_family = AF_UNSPEC; | |
756 | hints.ai_socktype = SOCK_STREAM; | |
757 | hints.ai_protocol = IPPROTO_TCP; | |
758 | hints.ai_flags = AI_PASSIVE; | |
759 | ||
760 | gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0); | |
761 | if (gai) { | |
762 | logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai)); | |
763 | return 0; | |
764 | } | |
765 | ||
766 | for (ai = ai0; ai; ai = ai->ai_next) { | |
767 | int sockfd; | |
768 | ||
769 | sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); | |
770 | if (sockfd < 0) | |
771 | continue; | |
772 | if (sockfd >= FD_SETSIZE) { | |
773 | logerror("Socket descriptor too large"); | |
774 | close(sockfd); | |
775 | continue; | |
776 | } | |
777 | ||
778 | #ifdef IPV6_V6ONLY | |
779 | if (ai->ai_family == AF_INET6) { | |
780 | int on = 1; | |
781 | setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY, | |
782 | &on, sizeof(on)); | |
783 | /* Note: error is not fatal */ | |
784 | } | |
785 | #endif | |
786 | ||
787 | if (set_reuse_addr(sockfd)) { | |
788 | close(sockfd); | |
789 | continue; | |
790 | } | |
791 | ||
792 | if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) { | |
793 | close(sockfd); | |
794 | continue; /* not fatal */ | |
795 | } | |
796 | if (listen(sockfd, 5) < 0) { | |
797 | close(sockfd); | |
798 | continue; /* not fatal */ | |
799 | } | |
800 | ||
801 | flags = fcntl(sockfd, F_GETFD, 0); | |
802 | if (flags >= 0) | |
803 | fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC); | |
804 | ||
805 | ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc); | |
806 | socklist->list[socklist->nr++] = sockfd; | |
807 | socknum++; | |
808 | ||
809 | if (maxfd < sockfd) | |
810 | maxfd = sockfd; | |
811 | } | |
812 | ||
813 | freeaddrinfo(ai0); | |
814 | ||
815 | return socknum; | |
816 | } | |
817 | ||
818 | #else /* NO_IPV6 */ | |
819 | ||
820 | static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist) | |
821 | { | |
822 | struct sockaddr_in sin; | |
823 | int sockfd; | |
824 | long flags; | |
825 | ||
826 | memset(&sin, 0, sizeof sin); | |
827 | sin.sin_family = AF_INET; | |
828 | sin.sin_port = htons(listen_port); | |
829 | ||
830 | if (listen_addr) { | |
831 | /* Well, host better be an IP address here. */ | |
832 | if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0) | |
833 | return 0; | |
834 | } else { | |
835 | sin.sin_addr.s_addr = htonl(INADDR_ANY); | |
836 | } | |
837 | ||
838 | sockfd = socket(AF_INET, SOCK_STREAM, 0); | |
839 | if (sockfd < 0) | |
840 | return 0; | |
841 | ||
842 | if (set_reuse_addr(sockfd)) { | |
843 | close(sockfd); | |
844 | return 0; | |
845 | } | |
846 | ||
847 | if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) { | |
848 | close(sockfd); | |
849 | return 0; | |
850 | } | |
851 | ||
852 | if (listen(sockfd, 5) < 0) { | |
853 | close(sockfd); | |
854 | return 0; | |
855 | } | |
856 | ||
857 | flags = fcntl(sockfd, F_GETFD, 0); | |
858 | if (flags >= 0) | |
859 | fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC); | |
860 | ||
861 | ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc); | |
862 | socklist->list[socklist->nr++] = sockfd; | |
863 | return 1; | |
864 | } | |
865 | ||
866 | #endif | |
867 | ||
868 | static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist) | |
869 | { | |
870 | if (!listen_addr->nr) | |
871 | setup_named_sock(NULL, listen_port, socklist); | |
872 | else { | |
873 | int i, socknum; | |
874 | for (i = 0; i < listen_addr->nr; i++) { | |
875 | socknum = setup_named_sock(listen_addr->items[i].string, | |
876 | listen_port, socklist); | |
877 | ||
878 | if (socknum == 0) | |
879 | logerror("unable to allocate any listen sockets for host %s on port %u", | |
880 | listen_addr->items[i].string, listen_port); | |
881 | } | |
882 | } | |
883 | } | |
884 | ||
885 | static int service_loop(struct socketlist *socklist) | |
886 | { | |
887 | struct pollfd *pfd; | |
888 | int i; | |
889 | ||
890 | pfd = xcalloc(socklist->nr, sizeof(struct pollfd)); | |
891 | ||
892 | for (i = 0; i < socklist->nr; i++) { | |
893 | pfd[i].fd = socklist->list[i]; | |
894 | pfd[i].events = POLLIN; | |
895 | } | |
896 | ||
897 | signal(SIGCHLD, child_handler); | |
898 | ||
899 | for (;;) { | |
900 | int i; | |
901 | ||
902 | check_dead_children(); | |
903 | ||
904 | if (poll(pfd, socklist->nr, -1) < 0) { | |
905 | if (errno != EINTR) { | |
906 | logerror("Poll failed, resuming: %s", | |
907 | strerror(errno)); | |
908 | sleep(1); | |
909 | } | |
910 | continue; | |
911 | } | |
912 | ||
913 | for (i = 0; i < socklist->nr; i++) { | |
914 | if (pfd[i].revents & POLLIN) { | |
915 | struct sockaddr_storage ss; | |
916 | unsigned int sslen = sizeof(ss); | |
917 | int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen); | |
918 | if (incoming < 0) { | |
919 | switch (errno) { | |
920 | case EAGAIN: | |
921 | case EINTR: | |
922 | case ECONNABORTED: | |
923 | continue; | |
924 | default: | |
925 | die_errno("accept returned"); | |
926 | } | |
927 | } | |
928 | handle(incoming, (struct sockaddr *)&ss, sslen); | |
929 | } | |
930 | } | |
931 | } | |
932 | } | |
933 | ||
934 | /* if any standard file descriptor is missing open it to /dev/null */ | |
935 | static void sanitize_stdfds(void) | |
936 | { | |
937 | int fd = open("/dev/null", O_RDWR, 0); | |
938 | while (fd != -1 && fd < 2) | |
939 | fd = dup(fd); | |
940 | if (fd == -1) | |
941 | die_errno("open /dev/null or dup failed"); | |
942 | if (fd > 2) | |
943 | close(fd); | |
944 | } | |
945 | ||
946 | static void daemonize(void) | |
947 | { | |
948 | switch (fork()) { | |
949 | case 0: | |
950 | break; | |
951 | case -1: | |
952 | die_errno("fork failed"); | |
953 | default: | |
954 | exit(0); | |
955 | } | |
956 | if (setsid() == -1) | |
957 | die_errno("setsid failed"); | |
958 | close(0); | |
959 | close(1); | |
960 | close(2); | |
961 | sanitize_stdfds(); | |
962 | } | |
963 | ||
964 | static void store_pid(const char *path) | |
965 | { | |
966 | FILE *f = fopen(path, "w"); | |
967 | if (!f) | |
968 | die_errno("cannot open pid file '%s'", path); | |
969 | if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0) | |
970 | die_errno("failed to write pid file '%s'", path); | |
971 | } | |
972 | ||
973 | static int serve(struct string_list *listen_addr, int listen_port, struct passwd *pass, gid_t gid) | |
974 | { | |
975 | struct socketlist socklist = { NULL, 0, 0 }; | |
976 | ||
977 | socksetup(listen_addr, listen_port, &socklist); | |
978 | if (socklist.nr == 0) | |
979 | die("unable to allocate any listen sockets on port %u", | |
980 | listen_port); | |
981 | ||
982 | if (pass && gid && | |
983 | (initgroups(pass->pw_name, gid) || setgid (gid) || | |
984 | setuid(pass->pw_uid))) | |
985 | die("cannot drop privileges"); | |
986 | ||
987 | return service_loop(&socklist); | |
988 | } | |
989 | ||
990 | int main(int argc, char **argv) | |
991 | { | |
992 | int listen_port = 0; | |
993 | struct string_list listen_addr = STRING_LIST_INIT_NODUP; | |
994 | int inetd_mode = 0; | |
995 | const char *pid_file = NULL, *user_name = NULL, *group_name = NULL; | |
996 | int detach = 0; | |
997 | struct passwd *pass = NULL; | |
998 | struct group *group; | |
999 | gid_t gid = 0; | |
1000 | int i; | |
1001 | ||
1002 | git_extract_argv0_path(argv[0]); | |
1003 | ||
1004 | for (i = 1; i < argc; i++) { | |
1005 | char *arg = argv[i]; | |
1006 | ||
1007 | if (!prefixcmp(arg, "--listen=")) { | |
1008 | string_list_append(&listen_addr, xstrdup_tolower(arg + 9)); | |
1009 | continue; | |
1010 | } | |
1011 | if (!prefixcmp(arg, "--port=")) { | |
1012 | char *end; | |
1013 | unsigned long n; | |
1014 | n = strtoul(arg+7, &end, 0); | |
1015 | if (arg[7] && !*end) { | |
1016 | listen_port = n; | |
1017 | continue; | |
1018 | } | |
1019 | } | |
1020 | if (!strcmp(arg, "--inetd")) { | |
1021 | inetd_mode = 1; | |
1022 | log_syslog = 1; | |
1023 | continue; | |
1024 | } | |
1025 | if (!strcmp(arg, "--verbose")) { | |
1026 | verbose = 1; | |
1027 | continue; | |
1028 | } | |
1029 | if (!strcmp(arg, "--syslog")) { | |
1030 | log_syslog = 1; | |
1031 | continue; | |
1032 | } | |
1033 | if (!strcmp(arg, "--export-all")) { | |
1034 | export_all_trees = 1; | |
1035 | continue; | |
1036 | } | |
1037 | if (!prefixcmp(arg, "--timeout=")) { | |
1038 | timeout = atoi(arg+10); | |
1039 | continue; | |
1040 | } | |
1041 | if (!prefixcmp(arg, "--init-timeout=")) { | |
1042 | init_timeout = atoi(arg+15); | |
1043 | continue; | |
1044 | } | |
1045 | if (!prefixcmp(arg, "--max-connections=")) { | |
1046 | max_connections = atoi(arg+18); | |
1047 | if (max_connections < 0) | |
1048 | max_connections = 0; /* unlimited */ | |
1049 | continue; | |
1050 | } | |
1051 | if (!strcmp(arg, "--strict-paths")) { | |
1052 | strict_paths = 1; | |
1053 | continue; | |
1054 | } | |
1055 | if (!prefixcmp(arg, "--base-path=")) { | |
1056 | base_path = arg+12; | |
1057 | continue; | |
1058 | } | |
1059 | if (!strcmp(arg, "--base-path-relaxed")) { | |
1060 | base_path_relaxed = 1; | |
1061 | continue; | |
1062 | } | |
1063 | if (!prefixcmp(arg, "--interpolated-path=")) { | |
1064 | interpolated_path = arg+20; | |
1065 | continue; | |
1066 | } | |
1067 | if (!strcmp(arg, "--reuseaddr")) { | |
1068 | reuseaddr = 1; | |
1069 | continue; | |
1070 | } | |
1071 | if (!strcmp(arg, "--user-path")) { | |
1072 | user_path = ""; | |
1073 | continue; | |
1074 | } | |
1075 | if (!prefixcmp(arg, "--user-path=")) { | |
1076 | user_path = arg + 12; | |
1077 | continue; | |
1078 | } | |
1079 | if (!prefixcmp(arg, "--pid-file=")) { | |
1080 | pid_file = arg + 11; | |
1081 | continue; | |
1082 | } | |
1083 | if (!strcmp(arg, "--detach")) { | |
1084 | detach = 1; | |
1085 | log_syslog = 1; | |
1086 | continue; | |
1087 | } | |
1088 | if (!prefixcmp(arg, "--user=")) { | |
1089 | user_name = arg + 7; | |
1090 | continue; | |
1091 | } | |
1092 | if (!prefixcmp(arg, "--group=")) { | |
1093 | group_name = arg + 8; | |
1094 | continue; | |
1095 | } | |
1096 | if (!prefixcmp(arg, "--enable=")) { | |
1097 | enable_service(arg + 9, 1); | |
1098 | continue; | |
1099 | } | |
1100 | if (!prefixcmp(arg, "--disable=")) { | |
1101 | enable_service(arg + 10, 0); | |
1102 | continue; | |
1103 | } | |
1104 | if (!prefixcmp(arg, "--allow-override=")) { | |
1105 | make_service_overridable(arg + 17, 1); | |
1106 | continue; | |
1107 | } | |
1108 | if (!prefixcmp(arg, "--forbid-override=")) { | |
1109 | make_service_overridable(arg + 18, 0); | |
1110 | continue; | |
1111 | } | |
1112 | if (!strcmp(arg, "--")) { | |
1113 | ok_paths = &argv[i+1]; | |
1114 | break; | |
1115 | } else if (arg[0] != '-') { | |
1116 | ok_paths = &argv[i]; | |
1117 | break; | |
1118 | } | |
1119 | ||
1120 | usage(daemon_usage); | |
1121 | } | |
1122 | ||
1123 | if (log_syslog) { | |
1124 | openlog("git-daemon", LOG_PID, LOG_DAEMON); | |
1125 | set_die_routine(daemon_die); | |
1126 | } else | |
1127 | /* avoid splitting a message in the middle */ | |
1128 | setvbuf(stderr, NULL, _IOLBF, 0); | |
1129 | ||
1130 | if (inetd_mode && (group_name || user_name)) | |
1131 | die("--user and --group are incompatible with --inetd"); | |
1132 | ||
1133 | if (inetd_mode && (listen_port || (listen_addr.nr > 0))) | |
1134 | die("--listen= and --port= are incompatible with --inetd"); | |
1135 | else if (listen_port == 0) | |
1136 | listen_port = DEFAULT_GIT_PORT; | |
1137 | ||
1138 | if (group_name && !user_name) | |
1139 | die("--group supplied without --user"); | |
1140 | ||
1141 | if (user_name) { | |
1142 | pass = getpwnam(user_name); | |
1143 | if (!pass) | |
1144 | die("user not found - %s", user_name); | |
1145 | ||
1146 | if (!group_name) | |
1147 | gid = pass->pw_gid; | |
1148 | else { | |
1149 | group = getgrnam(group_name); | |
1150 | if (!group) | |
1151 | die("group not found - %s", group_name); | |
1152 | ||
1153 | gid = group->gr_gid; | |
1154 | } | |
1155 | } | |
1156 | ||
1157 | if (strict_paths && (!ok_paths || !*ok_paths)) | |
1158 | die("option --strict-paths requires a whitelist"); | |
1159 | ||
1160 | if (base_path && !is_directory(base_path)) | |
1161 | die("base-path '%s' does not exist or is not a directory", | |
1162 | base_path); | |
1163 | ||
1164 | if (inetd_mode) { | |
1165 | struct sockaddr_storage ss; | |
1166 | struct sockaddr *peer = (struct sockaddr *)&ss; | |
1167 | socklen_t slen = sizeof(ss); | |
1168 | ||
1169 | if (!freopen("/dev/null", "w", stderr)) | |
1170 | die_errno("failed to redirect stderr to /dev/null"); | |
1171 | ||
1172 | if (getpeername(0, peer, &slen)) | |
1173 | peer = NULL; | |
1174 | ||
1175 | return execute(peer); | |
1176 | } | |
1177 | ||
1178 | if (detach) { | |
1179 | daemonize(); | |
1180 | loginfo("Ready to rumble"); | |
1181 | } | |
1182 | else | |
1183 | sanitize_stdfds(); | |
1184 | ||
1185 | if (pid_file) | |
1186 | store_pid(pid_file); | |
1187 | ||
1188 | return serve(&listen_addr, listen_port, pass, gid); | |
1189 | } |