Merge branch 'maint'
[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         close(proc.in);
136         return hook_status(finish_command(&proc), hook_name);
137 }
138
139 static int run_update_hook(struct command *cmd)
140 {
141         static const char update_hook[] = "hooks/update";
142         struct child_process proc;
143         const char *argv[5];
144
145         if (access(update_hook, X_OK) < 0)
146                 return 0;
147
148         argv[0] = update_hook;
149         argv[1] = cmd->ref_name;
150         argv[2] = sha1_to_hex(cmd->old_sha1);
151         argv[3] = sha1_to_hex(cmd->new_sha1);
152         argv[4] = NULL;
153
154         memset(&proc, 0, sizeof(proc));
155         proc.argv = argv;
156         proc.no_stdin = 1;
157         proc.stdout_to_stderr = 1;
158
159         return hook_status(run_command(&proc), update_hook);
160 }
161
162 static const char *update(struct command *cmd)
163 {
164         const char *name = cmd->ref_name;
165         unsigned char *old_sha1 = cmd->old_sha1;
166         unsigned char *new_sha1 = cmd->new_sha1;
167         struct ref_lock *lock;
168
169         /* only refs/... are allowed */
170         if (prefixcmp(name, "refs/") || check_ref_format(name + 5)) {
171                 error("refusing to create funny ref '%s' remotely", name);
172                 return "funny refname";
173         }
174
175         if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
176                 error("unpack should have generated %s, "
177                       "but I can't find it!", sha1_to_hex(new_sha1));
178                 return "bad pack";
179         }
180         if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
181             !is_null_sha1(old_sha1) &&
182             !prefixcmp(name, "refs/heads/")) {
183                 struct object *old_object, *new_object;
184                 struct commit *old_commit, *new_commit;
185                 struct commit_list *bases, *ent;
186
187                 old_object = parse_object(old_sha1);
188                 new_object = parse_object(new_sha1);
189
190                 if (!old_object || !new_object ||
191                     old_object->type != OBJ_COMMIT ||
192                     new_object->type != OBJ_COMMIT) {
193                         error("bad sha1 objects for %s", name);
194                         return "bad ref";
195                 }
196                 old_commit = (struct commit *)old_object;
197                 new_commit = (struct commit *)new_object;
198                 bases = get_merge_bases(old_commit, new_commit, 1);
199                 for (ent = bases; ent; ent = ent->next)
200                         if (!hashcmp(old_sha1, ent->item->object.sha1))
201                                 break;
202                 free_commit_list(bases);
203                 if (!ent) {
204                         error("denying non-fast forward %s"
205                               " (you should pull first)", name);
206                         return "non-fast forward";
207                 }
208         }
209         if (run_update_hook(cmd)) {
210                 error("hook declined to update %s", name);
211                 return "hook declined";
212         }
213
214         if (is_null_sha1(new_sha1)) {
215                 if (!parse_object(old_sha1)) {
216                         warning ("Allowing deletion of corrupt ref.");
217                         old_sha1 = NULL;
218                 }
219                 if (delete_ref(name, old_sha1)) {
220                         error("failed to delete %s", name);
221                         return "failed to delete";
222                 }
223                 return NULL; /* good */
224         }
225         else {
226                 lock = lock_any_ref_for_update(name, old_sha1, 0);
227                 if (!lock) {
228                         error("failed to lock %s", name);
229                         return "failed to lock";
230                 }
231                 if (write_ref_sha1(lock, new_sha1, "push")) {
232                         return "failed to write"; /* error() already called */
233                 }
234                 return NULL; /* good */
235         }
236 }
237
238 static char update_post_hook[] = "hooks/post-update";
239
240 static void run_update_post_hook(struct command *cmd)
241 {
242         struct command *cmd_p;
243         int argc;
244         const char **argv;
245
246         for (argc = 0, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
247                 if (cmd_p->error_string)
248                         continue;
249                 argc++;
250         }
251         if (!argc || access(update_post_hook, X_OK) < 0)
252                 return;
253         argv = xmalloc(sizeof(*argv) * (2 + argc));
254         argv[0] = update_post_hook;
255
256         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
257                 char *p;
258                 if (cmd_p->error_string)
259                         continue;
260                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
261                 strcpy(p, cmd_p->ref_name);
262                 argv[argc] = p;
263                 argc++;
264         }
265         argv[argc] = NULL;
266         run_command_v_opt(argv, RUN_COMMAND_NO_STDIN
267                 | RUN_COMMAND_STDOUT_TO_STDERR);
268 }
269
270 static void execute_commands(const char *unpacker_error)
271 {
272         struct command *cmd = commands;
273
274         if (unpacker_error) {
275                 while (cmd) {
276                         cmd->error_string = "n/a (unpacker error)";
277                         cmd = cmd->next;
278                 }
279                 return;
280         }
281
282         if (run_hook(pre_receive_hook)) {
283                 while (cmd) {
284                         cmd->error_string = "pre-receive hook declined";
285                         cmd = cmd->next;
286                 }
287                 return;
288         }
289
290         while (cmd) {
291                 cmd->error_string = update(cmd);
292                 cmd = cmd->next;
293         }
294 }
295
296 static void read_head_info(void)
297 {
298         struct command **p = &commands;
299         for (;;) {
300                 static char line[1000];
301                 unsigned char old_sha1[20], new_sha1[20];
302                 struct command *cmd;
303                 char *refname;
304                 int len, reflen;
305
306                 len = packet_read_line(0, line, sizeof(line));
307                 if (!len)
308                         break;
309                 if (line[len-1] == '\n')
310                         line[--len] = 0;
311                 if (len < 83 ||
312                     line[40] != ' ' ||
313                     line[81] != ' ' ||
314                     get_sha1_hex(line, old_sha1) ||
315                     get_sha1_hex(line + 41, new_sha1))
316                         die("protocol error: expected old/new/ref, got '%s'",
317                             line);
318
319                 refname = line + 82;
320                 reflen = strlen(refname);
321                 if (reflen + 82 < len) {
322                         if (strstr(refname + reflen + 1, "report-status"))
323                                 report_status = 1;
324                 }
325                 cmd = xmalloc(sizeof(struct command) + len - 80);
326                 hashcpy(cmd->old_sha1, old_sha1);
327                 hashcpy(cmd->new_sha1, new_sha1);
328                 memcpy(cmd->ref_name, line + 82, len - 81);
329                 cmd->error_string = NULL;
330                 cmd->next = NULL;
331                 *p = cmd;
332                 p = &cmd->next;
333         }
334 }
335
336 static const char *parse_pack_header(struct pack_header *hdr)
337 {
338         switch (read_pack_header(0, hdr)) {
339         case PH_ERROR_EOF:
340                 return "eof before pack header was fully read";
341
342         case PH_ERROR_PACK_SIGNATURE:
343                 return "protocol error (pack signature mismatch detected)";
344
345         case PH_ERROR_PROTOCOL:
346                 return "protocol error (pack version unsupported)";
347
348         default:
349                 return "unknown error in parse_pack_header";
350
351         case 0:
352                 return NULL;
353         }
354 }
355
356 static const char *pack_lockfile;
357
358 static const char *unpack(void)
359 {
360         struct pack_header hdr;
361         const char *hdr_err;
362         char hdr_arg[38];
363
364         hdr_err = parse_pack_header(&hdr);
365         if (hdr_err)
366                 return hdr_err;
367         snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
368                         ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
369
370         if (ntohl(hdr.hdr_entries) < unpack_limit) {
371                 int code;
372                 const char *unpacker[3];
373                 unpacker[0] = "unpack-objects";
374                 unpacker[1] = hdr_arg;
375                 unpacker[2] = NULL;
376                 code = run_command_v_opt(unpacker, RUN_GIT_CMD);
377                 switch (code) {
378                 case 0:
379                         return NULL;
380                 case -ERR_RUN_COMMAND_FORK:
381                         return "unpack fork failed";
382                 case -ERR_RUN_COMMAND_EXEC:
383                         return "unpack execute failed";
384                 case -ERR_RUN_COMMAND_WAITPID:
385                         return "waitpid failed";
386                 case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
387                         return "waitpid is confused";
388                 case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
389                         return "unpacker died of signal";
390                 case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
391                         return "unpacker died strangely";
392                 default:
393                         return "unpacker exited with error code";
394                 }
395         } else {
396                 const char *keeper[6];
397                 int s, status;
398                 char keep_arg[256];
399                 struct child_process ip;
400
401                 s = sprintf(keep_arg, "--keep=receive-pack %i on ", getpid());
402                 if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
403                         strcpy(keep_arg + s, "localhost");
404
405                 keeper[0] = "index-pack";
406                 keeper[1] = "--stdin";
407                 keeper[2] = "--fix-thin";
408                 keeper[3] = hdr_arg;
409                 keeper[4] = keep_arg;
410                 keeper[5] = NULL;
411                 memset(&ip, 0, sizeof(ip));
412                 ip.argv = keeper;
413                 ip.out = -1;
414                 ip.git_cmd = 1;
415                 if (start_command(&ip))
416                         return "index-pack fork failed";
417                 pack_lockfile = index_pack_lockfile(ip.out);
418                 close(ip.out);
419                 status = finish_command(&ip);
420                 if (!status) {
421                         reprepare_packed_git();
422                         return NULL;
423                 }
424                 return "index-pack abnormal exit";
425         }
426 }
427
428 static void report(const char *unpack_status)
429 {
430         struct command *cmd;
431         packet_write(1, "unpack %s\n",
432                      unpack_status ? unpack_status : "ok");
433         for (cmd = commands; cmd; cmd = cmd->next) {
434                 if (!cmd->error_string)
435                         packet_write(1, "ok %s\n",
436                                      cmd->ref_name);
437                 else
438                         packet_write(1, "ng %s %s\n",
439                                      cmd->ref_name, cmd->error_string);
440         }
441         packet_flush(1);
442 }
443
444 static int delete_only(struct command *cmd)
445 {
446         while (cmd) {
447                 if (!is_null_sha1(cmd->new_sha1))
448                         return 0;
449                 cmd = cmd->next;
450         }
451         return 1;
452 }
453
454 int main(int argc, char **argv)
455 {
456         int i;
457         char *dir = NULL;
458
459         argv++;
460         for (i = 1; i < argc; i++) {
461                 char *arg = *argv++;
462
463                 if (*arg == '-') {
464                         /* Do flag handling here */
465                         usage(receive_pack_usage);
466                 }
467                 if (dir)
468                         usage(receive_pack_usage);
469                 dir = arg;
470         }
471         if (!dir)
472                 usage(receive_pack_usage);
473
474         setup_path(NULL);
475
476         if (!enter_repo(dir, 0))
477                 die("'%s': unable to chdir or not a git archive", dir);
478
479         if (is_repository_shallow())
480                 die("attempt to push into a shallow repository");
481
482         git_config(receive_pack_config);
483
484         if (0 <= transfer_unpack_limit)
485                 unpack_limit = transfer_unpack_limit;
486         else if (0 <= receive_unpack_limit)
487                 unpack_limit = receive_unpack_limit;
488
489         write_head_info();
490
491         /* EOF */
492         packet_flush(1);
493
494         read_head_info();
495         if (commands) {
496                 const char *unpack_status = NULL;
497
498                 if (!delete_only(commands))
499                         unpack_status = unpack();
500                 execute_commands(unpack_status);
501                 if (pack_lockfile)
502                         unlink(pack_lockfile);
503                 if (report_status)
504                         report(unpack_status);
505                 run_hook(post_receive_hook);
506                 run_update_post_hook(commands);
507         }
508         return 0;
509 }