Merge branch 'sp/maint-http-backend-die-triggers-die-recursively' into maint
[git] / transport-helper.c
1 #include "cache.h"
2 #include "transport.h"
3 #include "quote.h"
4 #include "run-command.h"
5 #include "commit.h"
6 #include "diff.h"
7 #include "revision.h"
8 #include "quote.h"
9 #include "remote.h"
10
11 static int debug;
12
13 struct helper_data
14 {
15         const char *name;
16         struct child_process *helper;
17         FILE *out;
18         unsigned fetch : 1,
19                 import : 1,
20                 option : 1,
21                 push : 1,
22                 connect : 1,
23                 no_disconnect_req : 1;
24         /* These go from remote name (as in "list") to private name */
25         struct refspec *refspecs;
26         int refspec_nr;
27         /* Transport options for fetch-pack/send-pack (should one of
28          * those be invoked).
29          */
30         struct git_transport_options transport_options;
31 };
32
33 static void sendline(struct helper_data *helper, struct strbuf *buffer)
34 {
35         if (debug)
36                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
37         if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
38                 != buffer->len)
39                 die_errno("Full write to remote helper failed");
40 }
41
42 static int recvline_fh(FILE *helper, struct strbuf *buffer)
43 {
44         strbuf_reset(buffer);
45         if (debug)
46                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
47         if (strbuf_getline(buffer, helper, '\n') == EOF) {
48                 if (debug)
49                         fprintf(stderr, "Debug: Remote helper quit.\n");
50                 exit(128);
51         }
52
53         if (debug)
54                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
55         return 0;
56 }
57
58 static int recvline(struct helper_data *helper, struct strbuf *buffer)
59 {
60         return recvline_fh(helper->out, buffer);
61 }
62
63 static void xchgline(struct helper_data *helper, struct strbuf *buffer)
64 {
65         sendline(helper, buffer);
66         recvline(helper, buffer);
67 }
68
69 static void write_constant(int fd, const char *str)
70 {
71         if (debug)
72                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
73         if (write_in_full(fd, str, strlen(str)) != strlen(str))
74                 die_errno("Full write to remote helper failed");
75 }
76
77 const char *remove_ext_force(const char *url)
78 {
79         if (url) {
80                 const char *colon = strchr(url, ':');
81                 if (colon && colon[1] == ':')
82                         return colon + 2;
83         }
84         return url;
85 }
86
87 static void do_take_over(struct transport *transport)
88 {
89         struct helper_data *data;
90         data = (struct helper_data *)transport->data;
91         transport_take_over(transport, data->helper);
92         fclose(data->out);
93         free(data);
94 }
95
96 static struct child_process *get_helper(struct transport *transport)
97 {
98         struct helper_data *data = transport->data;
99         struct strbuf buf = STRBUF_INIT;
100         struct child_process *helper;
101         const char **refspecs = NULL;
102         int refspec_nr = 0;
103         int refspec_alloc = 0;
104         int duped;
105         int code;
106
107         if (data->helper)
108                 return data->helper;
109
110         helper = xcalloc(1, sizeof(*helper));
111         helper->in = -1;
112         helper->out = -1;
113         helper->err = 0;
114         helper->argv = xcalloc(4, sizeof(*helper->argv));
115         strbuf_addf(&buf, "git-remote-%s", data->name);
116         helper->argv[0] = strbuf_detach(&buf, NULL);
117         helper->argv[1] = transport->remote->name;
118         helper->argv[2] = remove_ext_force(transport->url);
119         helper->git_cmd = 0;
120         helper->silent_exec_failure = 1;
121         code = start_command(helper);
122         if (code < 0 && errno == ENOENT)
123                 die("Unable to find remote helper for '%s'", data->name);
124         else if (code != 0)
125                 exit(code);
126
127         data->helper = helper;
128         data->no_disconnect_req = 0;
129
130         /*
131          * Open the output as FILE* so strbuf_getline() can be used.
132          * Do this with duped fd because fclose() will close the fd,
133          * and stuff like taking over will require the fd to remain.
134          */
135         duped = dup(helper->out);
136         if (duped < 0)
137                 die_errno("Can't dup helper output fd");
138         data->out = xfdopen(duped, "r");
139
140         write_constant(helper->in, "capabilities\n");
141
142         while (1) {
143                 const char *capname;
144                 int mandatory = 0;
145                 recvline(data, &buf);
146
147                 if (!*buf.buf)
148                         break;
149
150                 if (*buf.buf == '*') {
151                         capname = buf.buf + 1;
152                         mandatory = 1;
153                 } else
154                         capname = buf.buf;
155
156                 if (debug)
157                         fprintf(stderr, "Debug: Got cap %s\n", capname);
158                 if (!strcmp(capname, "fetch"))
159                         data->fetch = 1;
160                 else if (!strcmp(capname, "option"))
161                         data->option = 1;
162                 else if (!strcmp(capname, "push"))
163                         data->push = 1;
164                 else if (!strcmp(capname, "import"))
165                         data->import = 1;
166                 else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
167                         ALLOC_GROW(refspecs,
168                                    refspec_nr + 1,
169                                    refspec_alloc);
170                         refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec "));
171                 } else if (!strcmp(capname, "connect")) {
172                         data->connect = 1;
173                 } else if (mandatory) {
174                         die("Unknown mandatory capability %s. This remote "
175                             "helper probably needs newer version of Git.\n",
176                             capname);
177                 }
178         }
179         if (refspecs) {
180                 int i;
181                 data->refspec_nr = refspec_nr;
182                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
183                 for (i = 0; i < refspec_nr; i++) {
184                         free((char *)refspecs[i]);
185                 }
186                 free(refspecs);
187         }
188         strbuf_release(&buf);
189         if (debug)
190                 fprintf(stderr, "Debug: Capabilities complete.\n");
191         return data->helper;
192 }
193
194 static int disconnect_helper(struct transport *transport)
195 {
196         struct helper_data *data = transport->data;
197         struct strbuf buf = STRBUF_INIT;
198
199         if (data->helper) {
200                 if (debug)
201                         fprintf(stderr, "Debug: Disconnecting.\n");
202                 if (!data->no_disconnect_req) {
203                         strbuf_addf(&buf, "\n");
204                         sendline(data, &buf);
205                 }
206                 close(data->helper->in);
207                 close(data->helper->out);
208                 fclose(data->out);
209                 finish_command(data->helper);
210                 free((char *)data->helper->argv[0]);
211                 free(data->helper->argv);
212                 free(data->helper);
213                 data->helper = NULL;
214         }
215         return 0;
216 }
217
218 static const char *unsupported_options[] = {
219         TRANS_OPT_UPLOADPACK,
220         TRANS_OPT_RECEIVEPACK,
221         TRANS_OPT_THIN,
222         TRANS_OPT_KEEP
223         };
224 static const char *boolean_options[] = {
225         TRANS_OPT_THIN,
226         TRANS_OPT_KEEP,
227         TRANS_OPT_FOLLOWTAGS
228         };
229
230 static int set_helper_option(struct transport *transport,
231                           const char *name, const char *value)
232 {
233         struct helper_data *data = transport->data;
234         struct strbuf buf = STRBUF_INIT;
235         int i, ret, is_bool = 0;
236
237         get_helper(transport);
238
239         if (!data->option)
240                 return 1;
241
242         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
243                 if (!strcmp(name, unsupported_options[i]))
244                         return 1;
245         }
246
247         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
248                 if (!strcmp(name, boolean_options[i])) {
249                         is_bool = 1;
250                         break;
251                 }
252         }
253
254         strbuf_addf(&buf, "option %s ", name);
255         if (is_bool)
256                 strbuf_addstr(&buf, value ? "true" : "false");
257         else
258                 quote_c_style(value, &buf, NULL, 0);
259         strbuf_addch(&buf, '\n');
260
261         xchgline(data, &buf);
262
263         if (!strcmp(buf.buf, "ok"))
264                 ret = 0;
265         else if (!prefixcmp(buf.buf, "error")) {
266                 ret = -1;
267         } else if (!strcmp(buf.buf, "unsupported"))
268                 ret = 1;
269         else {
270                 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
271                 ret = 1;
272         }
273         strbuf_release(&buf);
274         return ret;
275 }
276
277 static void standard_options(struct transport *t)
278 {
279         char buf[16];
280         int n;
281         int v = t->verbose;
282         int no_progress = v < 0 || (!t->progress && !isatty(2));
283
284         set_helper_option(t, "progress", !no_progress ? "true" : "false");
285
286         n = snprintf(buf, sizeof(buf), "%d", v + 1);
287         if (n >= sizeof(buf))
288                 die("impossibly large verbosity value");
289         set_helper_option(t, "verbosity", buf);
290 }
291
292 static int release_helper(struct transport *transport)
293 {
294         struct helper_data *data = transport->data;
295         free_refspec(data->refspec_nr, data->refspecs);
296         data->refspecs = NULL;
297         disconnect_helper(transport);
298         free(transport->data);
299         return 0;
300 }
301
302 static int fetch_with_fetch(struct transport *transport,
303                             int nr_heads, struct ref **to_fetch)
304 {
305         struct helper_data *data = transport->data;
306         int i;
307         struct strbuf buf = STRBUF_INIT;
308
309         standard_options(transport);
310
311         for (i = 0; i < nr_heads; i++) {
312                 const struct ref *posn = to_fetch[i];
313                 if (posn->status & REF_STATUS_UPTODATE)
314                         continue;
315
316                 strbuf_addf(&buf, "fetch %s %s\n",
317                             sha1_to_hex(posn->old_sha1), posn->name);
318         }
319
320         strbuf_addch(&buf, '\n');
321         sendline(data, &buf);
322
323         while (1) {
324                 recvline(data, &buf);
325
326                 if (!prefixcmp(buf.buf, "lock ")) {
327                         const char *name = buf.buf + 5;
328                         if (transport->pack_lockfile)
329                                 warning("%s also locked %s", data->name, name);
330                         else
331                                 transport->pack_lockfile = xstrdup(name);
332                 }
333                 else if (!buf.len)
334                         break;
335                 else
336                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
337         }
338         strbuf_release(&buf);
339         return 0;
340 }
341
342 static int get_importer(struct transport *transport, struct child_process *fastimport)
343 {
344         struct child_process *helper = get_helper(transport);
345         memset(fastimport, 0, sizeof(*fastimport));
346         fastimport->in = helper->out;
347         fastimport->argv = xcalloc(5, sizeof(*fastimport->argv));
348         fastimport->argv[0] = "fast-import";
349         fastimport->argv[1] = "--quiet";
350
351         fastimport->git_cmd = 1;
352         return start_command(fastimport);
353 }
354
355 static int fetch_with_import(struct transport *transport,
356                              int nr_heads, struct ref **to_fetch)
357 {
358         struct child_process fastimport;
359         struct helper_data *data = transport->data;
360         int i;
361         struct ref *posn;
362         struct strbuf buf = STRBUF_INIT;
363
364         get_helper(transport);
365
366         if (get_importer(transport, &fastimport))
367                 die("Couldn't run fast-import");
368
369         for (i = 0; i < nr_heads; i++) {
370                 posn = to_fetch[i];
371                 if (posn->status & REF_STATUS_UPTODATE)
372                         continue;
373
374                 strbuf_addf(&buf, "import %s\n", posn->name);
375                 sendline(data, &buf);
376                 strbuf_reset(&buf);
377         }
378         disconnect_helper(transport);
379         finish_command(&fastimport);
380         free(fastimport.argv);
381         fastimport.argv = NULL;
382
383         for (i = 0; i < nr_heads; i++) {
384                 char *private;
385                 posn = to_fetch[i];
386                 if (posn->status & REF_STATUS_UPTODATE)
387                         continue;
388                 if (data->refspecs)
389                         private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
390                 else
391                         private = strdup(posn->name);
392                 read_ref(private, posn->old_sha1);
393                 free(private);
394         }
395         strbuf_release(&buf);
396         return 0;
397 }
398
399 static int process_connect_service(struct transport *transport,
400                                    const char *name, const char *exec)
401 {
402         struct helper_data *data = transport->data;
403         struct strbuf cmdbuf = STRBUF_INIT;
404         struct child_process *helper;
405         int r, duped, ret = 0;
406         FILE *input;
407
408         helper = get_helper(transport);
409
410         /*
411          * Yes, dup the pipe another time, as we need unbuffered version
412          * of input pipe as FILE*. fclose() closes the underlying fd and
413          * stream buffering only can be changed before first I/O operation
414          * on it.
415          */
416         duped = dup(helper->out);
417         if (duped < 0)
418                 die_errno("Can't dup helper output fd");
419         input = xfdopen(duped, "r");
420         setvbuf(input, NULL, _IONBF, 0);
421
422         /*
423          * Handle --upload-pack and friends. This is fire and forget...
424          * just warn if it fails.
425          */
426         if (strcmp(name, exec)) {
427                 r = set_helper_option(transport, "servpath", exec);
428                 if (r > 0)
429                         warning("Setting remote service path not supported by protocol.");
430                 else if (r < 0)
431                         warning("Invalid remote service path.");
432         }
433
434         if (data->connect)
435                 strbuf_addf(&cmdbuf, "connect %s\n", name);
436         else
437                 goto exit;
438
439         sendline(data, &cmdbuf);
440         recvline_fh(input, &cmdbuf);
441         if (!strcmp(cmdbuf.buf, "")) {
442                 data->no_disconnect_req = 1;
443                 if (debug)
444                         fprintf(stderr, "Debug: Smart transport connection "
445                                 "ready.\n");
446                 ret = 1;
447         } else if (!strcmp(cmdbuf.buf, "fallback")) {
448                 if (debug)
449                         fprintf(stderr, "Debug: Falling back to dumb "
450                                 "transport.\n");
451         } else
452                 die("Unknown response to connect: %s",
453                         cmdbuf.buf);
454
455 exit:
456         fclose(input);
457         return ret;
458 }
459
460 static int process_connect(struct transport *transport,
461                                      int for_push)
462 {
463         struct helper_data *data = transport->data;
464         const char *name;
465         const char *exec;
466
467         name = for_push ? "git-receive-pack" : "git-upload-pack";
468         if (for_push)
469                 exec = data->transport_options.receivepack;
470         else
471                 exec = data->transport_options.uploadpack;
472
473         return process_connect_service(transport, name, exec);
474 }
475
476 static int connect_helper(struct transport *transport, const char *name,
477                    const char *exec, int fd[2])
478 {
479         struct helper_data *data = transport->data;
480
481         /* Get_helper so connect is inited. */
482         get_helper(transport);
483         if (!data->connect)
484                 die("Operation not supported by protocol.");
485
486         if (!process_connect_service(transport, name, exec))
487                 die("Can't connect to subservice %s.", name);
488
489         fd[0] = data->helper->out;
490         fd[1] = data->helper->in;
491         return 0;
492 }
493
494 static int fetch(struct transport *transport,
495                  int nr_heads, struct ref **to_fetch)
496 {
497         struct helper_data *data = transport->data;
498         int i, count;
499
500         if (process_connect(transport, 0)) {
501                 do_take_over(transport);
502                 return transport->fetch(transport, nr_heads, to_fetch);
503         }
504
505         count = 0;
506         for (i = 0; i < nr_heads; i++)
507                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
508                         count++;
509
510         if (!count)
511                 return 0;
512
513         if (data->fetch)
514                 return fetch_with_fetch(transport, nr_heads, to_fetch);
515
516         if (data->import)
517                 return fetch_with_import(transport, nr_heads, to_fetch);
518
519         return -1;
520 }
521
522 static int push_refs(struct transport *transport,
523                 struct ref *remote_refs, int flags)
524 {
525         int force_all = flags & TRANSPORT_PUSH_FORCE;
526         int mirror = flags & TRANSPORT_PUSH_MIRROR;
527         struct helper_data *data = transport->data;
528         struct strbuf buf = STRBUF_INIT;
529         struct child_process *helper;
530         struct ref *ref;
531
532         if (process_connect(transport, 1)) {
533                 do_take_over(transport);
534                 return transport->push_refs(transport, remote_refs, flags);
535         }
536
537         if (!remote_refs) {
538                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
539                         "Perhaps you should specify a branch such as 'master'.\n");
540                 return 0;
541         }
542
543         helper = get_helper(transport);
544         if (!data->push)
545                 return 1;
546
547         for (ref = remote_refs; ref; ref = ref->next) {
548                 if (!ref->peer_ref && !mirror)
549                         continue;
550
551                 /* Check for statuses set by set_ref_status_for_push() */
552                 switch (ref->status) {
553                 case REF_STATUS_REJECT_NONFASTFORWARD:
554                 case REF_STATUS_UPTODATE:
555                         continue;
556                 default:
557                         ; /* do nothing */
558                 }
559
560                 if (force_all)
561                         ref->force = 1;
562
563                 strbuf_addstr(&buf, "push ");
564                 if (!ref->deletion) {
565                         if (ref->force)
566                                 strbuf_addch(&buf, '+');
567                         if (ref->peer_ref)
568                                 strbuf_addstr(&buf, ref->peer_ref->name);
569                         else
570                                 strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
571                 }
572                 strbuf_addch(&buf, ':');
573                 strbuf_addstr(&buf, ref->name);
574                 strbuf_addch(&buf, '\n');
575         }
576         if (buf.len == 0)
577                 return 0;
578
579         transport->verbose = flags & TRANSPORT_PUSH_VERBOSE ? 1 : 0;
580         standard_options(transport);
581
582         if (flags & TRANSPORT_PUSH_DRY_RUN) {
583                 if (set_helper_option(transport, "dry-run", "true") != 0)
584                         die("helper %s does not support dry-run", data->name);
585         }
586
587         strbuf_addch(&buf, '\n');
588         sendline(data, &buf);
589
590         ref = remote_refs;
591         while (1) {
592                 char *refname, *msg;
593                 int status;
594
595                 recvline(data, &buf);
596                 if (!buf.len)
597                         break;
598
599                 if (!prefixcmp(buf.buf, "ok ")) {
600                         status = REF_STATUS_OK;
601                         refname = buf.buf + 3;
602                 } else if (!prefixcmp(buf.buf, "error ")) {
603                         status = REF_STATUS_REMOTE_REJECT;
604                         refname = buf.buf + 6;
605                 } else
606                         die("expected ok/error, helper said '%s'\n", buf.buf);
607
608                 msg = strchr(refname, ' ');
609                 if (msg) {
610                         struct strbuf msg_buf = STRBUF_INIT;
611                         const char *end;
612
613                         *msg++ = '\0';
614                         if (!unquote_c_style(&msg_buf, msg, &end))
615                                 msg = strbuf_detach(&msg_buf, NULL);
616                         else
617                                 msg = xstrdup(msg);
618                         strbuf_release(&msg_buf);
619
620                         if (!strcmp(msg, "no match")) {
621                                 status = REF_STATUS_NONE;
622                                 free(msg);
623                                 msg = NULL;
624                         }
625                         else if (!strcmp(msg, "up to date")) {
626                                 status = REF_STATUS_UPTODATE;
627                                 free(msg);
628                                 msg = NULL;
629                         }
630                         else if (!strcmp(msg, "non-fast forward")) {
631                                 status = REF_STATUS_REJECT_NONFASTFORWARD;
632                                 free(msg);
633                                 msg = NULL;
634                         }
635                 }
636
637                 if (ref)
638                         ref = find_ref_by_name(ref, refname);
639                 if (!ref)
640                         ref = find_ref_by_name(remote_refs, refname);
641                 if (!ref) {
642                         warning("helper reported unexpected status of %s", refname);
643                         continue;
644                 }
645
646                 if (ref->status != REF_STATUS_NONE) {
647                         /*
648                          * Earlier, the ref was marked not to be pushed, so ignore the ref
649                          * status reported by the remote helper if the latter is 'no match'.
650                          */
651                         if (status == REF_STATUS_NONE)
652                                 continue;
653                 }
654
655                 ref->status = status;
656                 ref->remote_status = msg;
657         }
658         strbuf_release(&buf);
659         return 0;
660 }
661
662 static int has_attribute(const char *attrs, const char *attr) {
663         int len;
664         if (!attrs)
665                 return 0;
666
667         len = strlen(attr);
668         for (;;) {
669                 const char *space = strchrnul(attrs, ' ');
670                 if (len == space - attrs && !strncmp(attrs, attr, len))
671                         return 1;
672                 if (!*space)
673                         return 0;
674                 attrs = space + 1;
675         }
676 }
677
678 static struct ref *get_refs_list(struct transport *transport, int for_push)
679 {
680         struct helper_data *data = transport->data;
681         struct child_process *helper;
682         struct ref *ret = NULL;
683         struct ref **tail = &ret;
684         struct ref *posn;
685         struct strbuf buf = STRBUF_INIT;
686
687         helper = get_helper(transport);
688
689         if (process_connect(transport, for_push)) {
690                 do_take_over(transport);
691                 return transport->get_refs_list(transport, for_push);
692         }
693
694         if (data->push && for_push)
695                 write_str_in_full(helper->in, "list for-push\n");
696         else
697                 write_str_in_full(helper->in, "list\n");
698
699         while (1) {
700                 char *eov, *eon;
701                 recvline(data, &buf);
702
703                 if (!*buf.buf)
704                         break;
705
706                 eov = strchr(buf.buf, ' ');
707                 if (!eov)
708                         die("Malformed response in ref list: %s", buf.buf);
709                 eon = strchr(eov + 1, ' ');
710                 *eov = '\0';
711                 if (eon)
712                         *eon = '\0';
713                 *tail = alloc_ref(eov + 1);
714                 if (buf.buf[0] == '@')
715                         (*tail)->symref = xstrdup(buf.buf + 1);
716                 else if (buf.buf[0] != '?')
717                         get_sha1_hex(buf.buf, (*tail)->old_sha1);
718                 if (eon) {
719                         if (has_attribute(eon + 1, "unchanged")) {
720                                 (*tail)->status |= REF_STATUS_UPTODATE;
721                                 read_ref((*tail)->name, (*tail)->old_sha1);
722                         }
723                 }
724                 tail = &((*tail)->next);
725         }
726         if (debug)
727                 fprintf(stderr, "Debug: Read ref listing.\n");
728         strbuf_release(&buf);
729
730         for (posn = ret; posn; posn = posn->next)
731                 resolve_remote_symref(posn, ret);
732
733         return ret;
734 }
735
736 int transport_helper_init(struct transport *transport, const char *name)
737 {
738         struct helper_data *data = xcalloc(sizeof(*data), 1);
739         data->name = name;
740
741         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
742                 debug = 1;
743
744         transport->data = data;
745         transport->set_option = set_helper_option;
746         transport->get_refs_list = get_refs_list;
747         transport->fetch = fetch;
748         transport->push_refs = push_refs;
749         transport->disconnect = release_helper;
750         transport->connect = connect_helper;
751         transport->smart_options = &(data->transport_options);
752         return 0;
753 }