receive-pack: check object type of sha1 before using them as commits
[git/git.git] / receive-pack.c
1 #include "cache.h"
2 #include "pack.h"
3 #include "refs.h"
4 #include "pkt-line.h"
5 #include "run-command.h"
6 #include "exec_cmd.h"
7 #include "commit.h"
8 #include "object.h"
9
10 static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
11
12 static int deny_non_fast_forwards = 0;
13 static int receive_unpack_limit = -1;
14 static int transfer_unpack_limit = -1;
15 static int unpack_limit = 100;
16 static int report_status;
17
18 static char capabilities[] = " report-status delete-refs ";
19 static int capabilities_sent;
20
21 static int receive_pack_config(const char *var, const char *value)
22 {
23 if (strcmp(var, "receive.denynonfastforwards") == 0) {
24 deny_non_fast_forwards = git_config_bool(var, value);
25 return 0;
26 }
27
28 if (strcmp(var, "receive.unpacklimit") == 0) {
29 receive_unpack_limit = git_config_int(var, value);
30 return 0;
31 }
32
33 if (strcmp(var, "transfer.unpacklimit") == 0) {
34 transfer_unpack_limit = git_config_int(var, value);
35 return 0;
36 }
37
38 return git_default_config(var, value);
39 }
40
41 static int show_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
42 {
43 if (capabilities_sent)
44 packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
45 else
46 packet_write(1, "%s %s%c%s\n",
47 sha1_to_hex(sha1), path, 0, capabilities);
48 capabilities_sent = 1;
49 return 0;
50 }
51
52 static void write_head_info(void)
53 {
54 for_each_ref(show_ref, NULL);
55 if (!capabilities_sent)
56 show_ref("capabilities^{}", null_sha1, 0, NULL);
57
58 }
59
60 struct command {
61 struct command *next;
62 const char *error_string;
63 unsigned char old_sha1[20];
64 unsigned char new_sha1[20];
65 char ref_name[FLEX_ARRAY]; /* more */
66 };
67
68 static struct command *commands;
69
70 static const char pre_receive_hook[] = "hooks/pre-receive";
71 static const char post_receive_hook[] = "hooks/post-receive";
72
73 static int hook_status(int code, const char *hook_name)
74 {
75 switch (code) {
76 case 0:
77 return 0;
78 case -ERR_RUN_COMMAND_FORK:
79 return error("hook fork failed");
80 case -ERR_RUN_COMMAND_EXEC:
81 return error("hook execute failed");
82 case -ERR_RUN_COMMAND_PIPE:
83 return error("hook pipe failed");
84 case -ERR_RUN_COMMAND_WAITPID:
85 return error("waitpid failed");
86 case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
87 return error("waitpid is confused");
88 case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
89 return error("%s died of signal", hook_name);
90 case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
91 return error("%s died strangely", hook_name);
92 default:
93 error("%s exited with error code %d", hook_name, -code);
94 return -code;
95 }
96 }
97
98 static int run_hook(const char *hook_name)
99 {
100 static char buf[sizeof(commands->old_sha1) * 2 + PATH_MAX + 4];
101 struct command *cmd;
102 struct child_process proc;
103 const char *argv[2];
104 int have_input = 0, code;
105
106 for (cmd = commands; !have_input && cmd; cmd = cmd->next) {
107 if (!cmd->error_string)
108 have_input = 1;
109 }
110
111 if (!have_input || access(hook_name, X_OK) < 0)
112 return 0;
113
114 argv[0] = hook_name;
115 argv[1] = NULL;
116
117 memset(&proc, 0, sizeof(proc));
118 proc.argv = argv;
119 proc.in = -1;
120 proc.stdout_to_stderr = 1;
121
122 code = start_command(&proc);
123 if (code)
124 return hook_status(code, hook_name);
125 for (cmd = commands; cmd; cmd = cmd->next) {
126 if (!cmd->error_string) {
127 size_t n = snprintf(buf, sizeof(buf), "%s %s %s\n",
128 sha1_to_hex(cmd->old_sha1),
129 sha1_to_hex(cmd->new_sha1),
130 cmd->ref_name);
131 if (write_in_full(proc.in, buf, n) != n)
132 break;
133 }
134 }
135 return hook_status(finish_command(&proc), hook_name);
136 }
137
138 static int run_update_hook(struct command *cmd)
139 {
140 static const char update_hook[] = "hooks/update";
141 struct child_process proc;
142 const char *argv[5];
143
144 if (access(update_hook, X_OK) < 0)
145 return 0;
146
147 argv[0] = update_hook;
148 argv[1] = cmd->ref_name;
149 argv[2] = sha1_to_hex(cmd->old_sha1);
150 argv[3] = sha1_to_hex(cmd->new_sha1);
151 argv[4] = NULL;
152
153 memset(&proc, 0, sizeof(proc));
154 proc.argv = argv;
155 proc.no_stdin = 1;
156 proc.stdout_to_stderr = 1;
157
158 return hook_status(run_command(&proc), update_hook);
159 }
160
161 static const char *update(struct command *cmd)
162 {
163 const char *name = cmd->ref_name;
164 unsigned char *old_sha1 = cmd->old_sha1;
165 unsigned char *new_sha1 = cmd->new_sha1;
166 struct ref_lock *lock;
167
168 if (!prefixcmp(name, "refs/") && check_ref_format(name + 5)) {
169 error("refusing to create funny ref '%s' remotely", name);
170 return "funny refname";
171 }
172
173 if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
174 error("unpack should have generated %s, "
175 "but I can't find it!", sha1_to_hex(new_sha1));
176 return "bad pack";
177 }
178 if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
179 !is_null_sha1(old_sha1) &&
180 !prefixcmp(name, "refs/heads/")) {
181 struct object *old_object, *new_object;
182 struct commit *old_commit, *new_commit;
183 struct commit_list *bases, *ent;
184
185 old_object = parse_object(old_sha1);
186 new_object = parse_object(new_sha1);
187
188 if (!old_object || !new_object ||
189 old_object->type != OBJ_COMMIT ||
190 new_object->type != OBJ_COMMIT) {
191 error("bad sha1 objects for %s", name);
192 return "bad ref";
193 }
194 old_commit = (struct commit *)old_object;
195 new_commit = (struct commit *)new_object;
196 bases = get_merge_bases(old_commit, new_commit, 1);
197 for (ent = bases; ent; ent = ent->next)
198 if (!hashcmp(old_sha1, ent->item->object.sha1))
199 break;
200 free_commit_list(bases);
201 if (!ent) {
202 error("denying non-fast forward %s"
203 " (you should pull first)", name);
204 return "non-fast forward";
205 }
206 }
207 if (run_update_hook(cmd)) {
208 error("hook declined to update %s", name);
209 return "hook declined";
210 }
211
212 if (is_null_sha1(new_sha1)) {
213 if (!parse_object(old_sha1)) {
214 warning ("Allowing deletion of corrupt ref.");
215 old_sha1 = NULL;
216 }
217 if (delete_ref(name, old_sha1)) {
218 error("failed to delete %s", name);
219 return "failed to delete";
220 }
221 return NULL; /* good */
222 }
223 else {
224 lock = lock_any_ref_for_update(name, old_sha1, 0);
225 if (!lock) {
226 error("failed to lock %s", name);
227 return "failed to lock";
228 }
229 if (write_ref_sha1(lock, new_sha1, "push")) {
230 return "failed to write"; /* error() already called */
231 }
232 return NULL; /* good */
233 }
234 }
235
236 static char update_post_hook[] = "hooks/post-update";
237
238 static void run_update_post_hook(struct command *cmd)
239 {
240 struct command *cmd_p;
241 int argc;
242 const char **argv;
243
244 for (argc = 0, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
245 if (cmd_p->error_string)
246 continue;
247 argc++;
248 }
249 if (!argc || access(update_post_hook, X_OK) < 0)
250 return;
251 argv = xmalloc(sizeof(*argv) * (2 + argc));
252 argv[0] = update_post_hook;
253
254 for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
255 char *p;
256 if (cmd_p->error_string)
257 continue;
258 p = xmalloc(strlen(cmd_p->ref_name) + 1);
259 strcpy(p, cmd_p->ref_name);
260 argv[argc] = p;
261 argc++;
262 }
263 argv[argc] = NULL;
264 run_command_v_opt(argv, RUN_COMMAND_NO_STDIN
265 | RUN_COMMAND_STDOUT_TO_STDERR);
266 }
267
268 static void execute_commands(const char *unpacker_error)
269 {
270 struct command *cmd = commands;
271
272 if (unpacker_error) {
273 while (cmd) {
274 cmd->error_string = "n/a (unpacker error)";
275 cmd = cmd->next;
276 }
277 return;
278 }
279
280 if (run_hook(pre_receive_hook)) {
281 while (cmd) {
282 cmd->error_string = "pre-receive hook declined";
283 cmd = cmd->next;
284 }
285 return;
286 }
287
288 while (cmd) {
289 cmd->error_string = update(cmd);
290 cmd = cmd->next;
291 }
292 }
293
294 static void read_head_info(void)
295 {
296 struct command **p = &commands;
297 for (;;) {
298 static char line[1000];
299 unsigned char old_sha1[20], new_sha1[20];
300 struct command *cmd;
301 char *refname;
302 int len, reflen;
303
304 len = packet_read_line(0, line, sizeof(line));
305 if (!len)
306 break;
307 if (line[len-1] == '\n')
308 line[--len] = 0;
309 if (len < 83 ||
310 line[40] != ' ' ||
311 line[81] != ' ' ||
312 get_sha1_hex(line, old_sha1) ||
313 get_sha1_hex(line + 41, new_sha1))
314 die("protocol error: expected old/new/ref, got '%s'",
315 line);
316
317 refname = line + 82;
318 reflen = strlen(refname);
319 if (reflen + 82 < len) {
320 if (strstr(refname + reflen + 1, "report-status"))
321 report_status = 1;
322 }
323 cmd = xmalloc(sizeof(struct command) + len - 80);
324 hashcpy(cmd->old_sha1, old_sha1);
325 hashcpy(cmd->new_sha1, new_sha1);
326 memcpy(cmd->ref_name, line + 82, len - 81);
327 cmd->error_string = NULL;
328 cmd->next = NULL;
329 *p = cmd;
330 p = &cmd->next;
331 }
332 }
333
334 static const char *parse_pack_header(struct pack_header *hdr)
335 {
336 switch (read_pack_header(0, hdr)) {
337 case PH_ERROR_EOF:
338 return "eof before pack header was fully read";
339
340 case PH_ERROR_PACK_SIGNATURE:
341 return "protocol error (pack signature mismatch detected)";
342
343 case PH_ERROR_PROTOCOL:
344 return "protocol error (pack version unsupported)";
345
346 default:
347 return "unknown error in parse_pack_header";
348
349 case 0:
350 return NULL;
351 }
352 }
353
354 static const char *pack_lockfile;
355
356 static const char *unpack(void)
357 {
358 struct pack_header hdr;
359 const char *hdr_err;
360 char hdr_arg[38];
361
362 hdr_err = parse_pack_header(&hdr);
363 if (hdr_err)
364 return hdr_err;
365 snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
366 ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
367
368 if (ntohl(hdr.hdr_entries) < unpack_limit) {
369 int code;
370 const char *unpacker[3];
371 unpacker[0] = "unpack-objects";
372 unpacker[1] = hdr_arg;
373 unpacker[2] = NULL;
374 code = run_command_v_opt(unpacker, RUN_GIT_CMD);
375 switch (code) {
376 case 0:
377 return NULL;
378 case -ERR_RUN_COMMAND_FORK:
379 return "unpack fork failed";
380 case -ERR_RUN_COMMAND_EXEC:
381 return "unpack execute failed";
382 case -ERR_RUN_COMMAND_WAITPID:
383 return "waitpid failed";
384 case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
385 return "waitpid is confused";
386 case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
387 return "unpacker died of signal";
388 case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
389 return "unpacker died strangely";
390 default:
391 return "unpacker exited with error code";
392 }
393 } else {
394 const char *keeper[6];
395 int s, status;
396 char keep_arg[256];
397 struct child_process ip;
398
399 s = sprintf(keep_arg, "--keep=receive-pack %i on ", getpid());
400 if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
401 strcpy(keep_arg + s, "localhost");
402
403 keeper[0] = "index-pack";
404 keeper[1] = "--stdin";
405 keeper[2] = "--fix-thin";
406 keeper[3] = hdr_arg;
407 keeper[4] = keep_arg;
408 keeper[5] = NULL;
409 memset(&ip, 0, sizeof(ip));
410 ip.argv = keeper;
411 ip.out = -1;
412 ip.git_cmd = 1;
413 if (start_command(&ip))
414 return "index-pack fork failed";
415 pack_lockfile = index_pack_lockfile(ip.out);
416 status = finish_command(&ip);
417 if (!status) {
418 reprepare_packed_git();
419 return NULL;
420 }
421 return "index-pack abnormal exit";
422 }
423 }
424
425 static void report(const char *unpack_status)
426 {
427 struct command *cmd;
428 packet_write(1, "unpack %s\n",
429 unpack_status ? unpack_status : "ok");
430 for (cmd = commands; cmd; cmd = cmd->next) {
431 if (!cmd->error_string)
432 packet_write(1, "ok %s\n",
433 cmd->ref_name);
434 else
435 packet_write(1, "ng %s %s\n",
436 cmd->ref_name, cmd->error_string);
437 }
438 packet_flush(1);
439 }
440
441 static int delete_only(struct command *cmd)
442 {
443 while (cmd) {
444 if (!is_null_sha1(cmd->new_sha1))
445 return 0;
446 cmd = cmd->next;
447 }
448 return 1;
449 }
450
451 int main(int argc, char **argv)
452 {
453 int i;
454 char *dir = NULL;
455
456 argv++;
457 for (i = 1; i < argc; i++) {
458 char *arg = *argv++;
459
460 if (*arg == '-') {
461 /* Do flag handling here */
462 usage(receive_pack_usage);
463 }
464 if (dir)
465 usage(receive_pack_usage);
466 dir = arg;
467 }
468 if (!dir)
469 usage(receive_pack_usage);
470
471 if (!enter_repo(dir, 0))
472 die("'%s': unable to chdir or not a git archive", dir);
473
474 if (is_repository_shallow())
475 die("attempt to push into a shallow repository");
476
477 git_config(receive_pack_config);
478
479 if (0 <= transfer_unpack_limit)
480 unpack_limit = transfer_unpack_limit;
481 else if (0 <= receive_unpack_limit)
482 unpack_limit = receive_unpack_limit;
483
484 write_head_info();
485
486 /* EOF */
487 packet_flush(1);
488
489 read_head_info();
490 if (commands) {
491 const char *unpack_status = NULL;
492
493 if (!delete_only(commands))
494 unpack_status = unpack();
495 execute_commands(unpack_status);
496 if (pack_lockfile)
497 unlink(pack_lockfile);
498 if (report_status)
499 report(unpack_status);
500 run_hook(post_receive_hook);
501 run_update_post_hook(commands);
502 }
503 return 0;
504 }