signed push: add "pushee" header to push certificate
[git] / send-pack.c
1 #include "builtin.h"
2 #include "commit.h"
3 #include "refs.h"
4 #include "pkt-line.h"
5 #include "sideband.h"
6 #include "run-command.h"
7 #include "remote.h"
8 #include "connect.h"
9 #include "send-pack.h"
10 #include "quote.h"
11 #include "transport.h"
12 #include "version.h"
13 #include "sha1-array.h"
14 #include "gpg-interface.h"
15
16 static int feed_object(const unsigned char *sha1, int fd, int negative)
17 {
18         char buf[42];
19
20         if (negative && !has_sha1_file(sha1))
21                 return 1;
22
23         memcpy(buf + negative, sha1_to_hex(sha1), 40);
24         if (negative)
25                 buf[0] = '^';
26         buf[40 + negative] = '\n';
27         return write_or_whine(fd, buf, 41 + negative, "send-pack: send refs");
28 }
29
30 /*
31  * Make a pack stream and spit it out into file descriptor fd
32  */
33 static int pack_objects(int fd, struct ref *refs, struct sha1_array *extra, struct send_pack_args *args)
34 {
35         /*
36          * The child becomes pack-objects --revs; we feed
37          * the revision parameters to it via its stdin and
38          * let its stdout go back to the other end.
39          */
40         const char *argv[] = {
41                 "pack-objects",
42                 "--all-progress-implied",
43                 "--revs",
44                 "--stdout",
45                 NULL,
46                 NULL,
47                 NULL,
48                 NULL,
49                 NULL,
50         };
51         struct child_process po;
52         int i;
53
54         i = 4;
55         if (args->use_thin_pack)
56                 argv[i++] = "--thin";
57         if (args->use_ofs_delta)
58                 argv[i++] = "--delta-base-offset";
59         if (args->quiet || !args->progress)
60                 argv[i++] = "-q";
61         if (args->progress)
62                 argv[i++] = "--progress";
63         memset(&po, 0, sizeof(po));
64         po.argv = argv;
65         po.in = -1;
66         po.out = args->stateless_rpc ? -1 : fd;
67         po.git_cmd = 1;
68         if (start_command(&po))
69                 die_errno("git pack-objects failed");
70
71         /*
72          * We feed the pack-objects we just spawned with revision
73          * parameters by writing to the pipe.
74          */
75         for (i = 0; i < extra->nr; i++)
76                 if (!feed_object(extra->sha1[i], po.in, 1))
77                         break;
78
79         while (refs) {
80                 if (!is_null_sha1(refs->old_sha1) &&
81                     !feed_object(refs->old_sha1, po.in, 1))
82                         break;
83                 if (!is_null_sha1(refs->new_sha1) &&
84                     !feed_object(refs->new_sha1, po.in, 0))
85                         break;
86                 refs = refs->next;
87         }
88
89         close(po.in);
90
91         if (args->stateless_rpc) {
92                 char *buf = xmalloc(LARGE_PACKET_MAX);
93                 while (1) {
94                         ssize_t n = xread(po.out, buf, LARGE_PACKET_MAX);
95                         if (n <= 0)
96                                 break;
97                         send_sideband(fd, -1, buf, n, LARGE_PACKET_MAX);
98                 }
99                 free(buf);
100                 close(po.out);
101                 po.out = -1;
102         }
103
104         if (finish_command(&po))
105                 return -1;
106         return 0;
107 }
108
109 static int receive_status(int in, struct ref *refs)
110 {
111         struct ref *hint;
112         int ret = 0;
113         char *line = packet_read_line(in, NULL);
114         if (!starts_with(line, "unpack "))
115                 return error("did not receive remote status");
116         if (strcmp(line, "unpack ok")) {
117                 error("unpack failed: %s", line + 7);
118                 ret = -1;
119         }
120         hint = NULL;
121         while (1) {
122                 char *refname;
123                 char *msg;
124                 line = packet_read_line(in, NULL);
125                 if (!line)
126                         break;
127                 if (!starts_with(line, "ok ") && !starts_with(line, "ng ")) {
128                         error("invalid ref status from remote: %s", line);
129                         ret = -1;
130                         break;
131                 }
132
133                 refname = line + 3;
134                 msg = strchr(refname, ' ');
135                 if (msg)
136                         *msg++ = '\0';
137
138                 /* first try searching at our hint, falling back to all refs */
139                 if (hint)
140                         hint = find_ref_by_name(hint, refname);
141                 if (!hint)
142                         hint = find_ref_by_name(refs, refname);
143                 if (!hint) {
144                         warning("remote reported status on unknown ref: %s",
145                                         refname);
146                         continue;
147                 }
148                 if (hint->status != REF_STATUS_EXPECTING_REPORT) {
149                         warning("remote reported status on unexpected ref: %s",
150                                         refname);
151                         continue;
152                 }
153
154                 if (line[0] == 'o' && line[1] == 'k')
155                         hint->status = REF_STATUS_OK;
156                 else {
157                         hint->status = REF_STATUS_REMOTE_REJECT;
158                         ret = -1;
159                 }
160                 if (msg)
161                         hint->remote_status = xstrdup(msg);
162                 /* start our next search from the next ref */
163                 hint = hint->next;
164         }
165         return ret;
166 }
167
168 static int sideband_demux(int in, int out, void *data)
169 {
170         int *fd = data, ret;
171 #ifdef NO_PTHREADS
172         close(fd[1]);
173 #endif
174         ret = recv_sideband("send-pack", fd[0], out);
175         close(out);
176         return ret;
177 }
178
179 static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
180 {
181         struct strbuf *sb = cb;
182         if (graft->nr_parent == -1)
183                 packet_buf_write(sb, "shallow %s\n", sha1_to_hex(graft->sha1));
184         return 0;
185 }
186
187 static void advertise_shallow_grafts_buf(struct strbuf *sb)
188 {
189         if (!is_repository_shallow())
190                 return;
191         for_each_commit_graft(advertise_shallow_grafts_cb, sb);
192 }
193
194 static int ref_update_to_be_sent(const struct ref *ref, const struct send_pack_args *args)
195 {
196         if (!ref->peer_ref && !args->send_mirror)
197                 return 0;
198
199         /* Check for statuses set by set_ref_status_for_push() */
200         switch (ref->status) {
201         case REF_STATUS_REJECT_NONFASTFORWARD:
202         case REF_STATUS_REJECT_ALREADY_EXISTS:
203         case REF_STATUS_REJECT_FETCH_FIRST:
204         case REF_STATUS_REJECT_NEEDS_FORCE:
205         case REF_STATUS_REJECT_STALE:
206         case REF_STATUS_REJECT_NODELETE:
207         case REF_STATUS_UPTODATE:
208                 return 0;
209         default:
210                 return 1;
211         }
212 }
213
214 /*
215  * the beginning of the next line, or the end of buffer.
216  *
217  * NEEDSWORK: perhaps move this to git-compat-util.h or somewhere and
218  * convert many similar uses found by "git grep -A4 memchr".
219  */
220 static const char *next_line(const char *line, size_t len)
221 {
222         const char *nl = memchr(line, '\n', len);
223         if (!nl)
224                 return line + len; /* incomplete line */
225         return nl + 1;
226 }
227
228 static int generate_push_cert(struct strbuf *req_buf,
229                               const struct ref *remote_refs,
230                               struct send_pack_args *args,
231                               const char *cap_string)
232 {
233         const struct ref *ref;
234         char stamp[60];
235         char *signing_key = xstrdup(get_signing_key());
236         const char *cp, *np;
237         struct strbuf cert = STRBUF_INIT;
238         int update_seen = 0;
239
240         datestamp(stamp, sizeof(stamp));
241         strbuf_addf(&cert, "certificate version 0.1\n");
242         strbuf_addf(&cert, "pusher %s %s\n", signing_key, stamp);
243         if (args->url && *args->url) {
244                 char *anon_url = transport_anonymize_url(args->url);
245                 strbuf_addf(&cert, "pushee %s\n", anon_url);
246                 free(anon_url);
247         }
248         strbuf_addstr(&cert, "\n");
249
250         for (ref = remote_refs; ref; ref = ref->next) {
251                 if (!ref_update_to_be_sent(ref, args))
252                         continue;
253                 update_seen = 1;
254                 strbuf_addf(&cert, "%s %s %s\n",
255                             sha1_to_hex(ref->old_sha1),
256                             sha1_to_hex(ref->new_sha1),
257                             ref->name);
258         }
259         if (!update_seen)
260                 goto free_return;
261
262         if (sign_buffer(&cert, &cert, signing_key))
263                 die(_("failed to sign the push certificate"));
264
265         packet_buf_write(req_buf, "push-cert%c%s", 0, cap_string);
266         for (cp = cert.buf; cp < cert.buf + cert.len; cp = np) {
267                 np = next_line(cp, cert.buf + cert.len - cp);
268                 packet_buf_write(req_buf,
269                                  "%.*s", (int)(np - cp), cp);
270         }
271         packet_buf_write(req_buf, "push-cert-end\n");
272
273 free_return:
274         free(signing_key);
275         strbuf_release(&cert);
276         return update_seen;
277 }
278
279 int send_pack(struct send_pack_args *args,
280               int fd[], struct child_process *conn,
281               struct ref *remote_refs,
282               struct sha1_array *extra_have)
283 {
284         int in = fd[0];
285         int out = fd[1];
286         struct strbuf req_buf = STRBUF_INIT;
287         struct strbuf cap_buf = STRBUF_INIT;
288         struct ref *ref;
289         int need_pack_data = 0;
290         int allow_deleting_refs = 0;
291         int status_report = 0;
292         int use_sideband = 0;
293         int quiet_supported = 0;
294         int agent_supported = 0;
295         unsigned cmds_sent = 0;
296         int ret;
297         struct async demux;
298
299         /* Does the other end support the reporting? */
300         if (server_supports("report-status"))
301                 status_report = 1;
302         if (server_supports("delete-refs"))
303                 allow_deleting_refs = 1;
304         if (server_supports("ofs-delta"))
305                 args->use_ofs_delta = 1;
306         if (server_supports("side-band-64k"))
307                 use_sideband = 1;
308         if (server_supports("quiet"))
309                 quiet_supported = 1;
310         if (server_supports("agent"))
311                 agent_supported = 1;
312         if (server_supports("no-thin"))
313                 args->use_thin_pack = 0;
314         if (args->push_cert && !server_supports("push-cert"))
315                 die(_("the receiving end does not support --signed push"));
316
317         if (!remote_refs) {
318                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
319                         "Perhaps you should specify a branch such as 'master'.\n");
320                 return 0;
321         }
322
323         if (status_report)
324                 strbuf_addstr(&cap_buf, " report-status");
325         if (use_sideband)
326                 strbuf_addstr(&cap_buf, " side-band-64k");
327         if (quiet_supported && (args->quiet || !args->progress))
328                 strbuf_addstr(&cap_buf, " quiet");
329         if (agent_supported)
330                 strbuf_addf(&cap_buf, " agent=%s", git_user_agent_sanitized());
331
332         /*
333          * NEEDSWORK: why does delete-refs have to be so specific to
334          * send-pack machinery that set_ref_status_for_push() cannot
335          * set this bit for us???
336          */
337         for (ref = remote_refs; ref; ref = ref->next)
338                 if (ref->deletion && !allow_deleting_refs)
339                         ref->status = REF_STATUS_REJECT_NODELETE;
340
341         if (!args->dry_run)
342                 advertise_shallow_grafts_buf(&req_buf);
343
344         if (!args->dry_run && args->push_cert)
345                 cmds_sent = generate_push_cert(&req_buf, remote_refs, args,
346                                                cap_buf.buf);
347
348         /*
349          * Clear the status for each ref and see if we need to send
350          * the pack data.
351          */
352         for (ref = remote_refs; ref; ref = ref->next) {
353                 if (!ref_update_to_be_sent(ref, args))
354                         continue;
355
356                 if (!ref->deletion)
357                         need_pack_data = 1;
358
359                 if (args->dry_run || !status_report)
360                         ref->status = REF_STATUS_OK;
361                 else
362                         ref->status = REF_STATUS_EXPECTING_REPORT;
363         }
364
365         /*
366          * Finally, tell the other end!
367          */
368         for (ref = remote_refs; ref; ref = ref->next) {
369                 char *old_hex, *new_hex;
370
371                 if (args->dry_run || args->push_cert)
372                         continue;
373
374                 if (!ref_update_to_be_sent(ref, args))
375                         continue;
376
377                 old_hex = sha1_to_hex(ref->old_sha1);
378                 new_hex = sha1_to_hex(ref->new_sha1);
379                 if (!cmds_sent) {
380                         packet_buf_write(&req_buf,
381                                          "%s %s %s%c%s",
382                                          old_hex, new_hex, ref->name, 0,
383                                          cap_buf.buf);
384                         cmds_sent = 1;
385                 } else {
386                         packet_buf_write(&req_buf, "%s %s %s",
387                                          old_hex, new_hex, ref->name);
388                 }
389         }
390
391         if (args->stateless_rpc) {
392                 if (!args->dry_run && (cmds_sent || is_repository_shallow())) {
393                         packet_buf_flush(&req_buf);
394                         send_sideband(out, -1, req_buf.buf, req_buf.len, LARGE_PACKET_MAX);
395                 }
396         } else {
397                 write_or_die(out, req_buf.buf, req_buf.len);
398                 packet_flush(out);
399         }
400         strbuf_release(&req_buf);
401         strbuf_release(&cap_buf);
402
403         if (use_sideband && cmds_sent) {
404                 memset(&demux, 0, sizeof(demux));
405                 demux.proc = sideband_demux;
406                 demux.data = fd;
407                 demux.out = -1;
408                 if (start_async(&demux))
409                         die("send-pack: unable to fork off sideband demultiplexer");
410                 in = demux.out;
411         }
412
413         if (need_pack_data && cmds_sent) {
414                 if (pack_objects(out, remote_refs, extra_have, args) < 0) {
415                         for (ref = remote_refs; ref; ref = ref->next)
416                                 ref->status = REF_STATUS_NONE;
417                         if (args->stateless_rpc)
418                                 close(out);
419                         if (git_connection_is_socket(conn))
420                                 shutdown(fd[0], SHUT_WR);
421                         if (use_sideband)
422                                 finish_async(&demux);
423                         fd[1] = -1;
424                         return -1;
425                 }
426                 if (!args->stateless_rpc)
427                         /* Closed by pack_objects() via start_command() */
428                         fd[1] = -1;
429         }
430         if (args->stateless_rpc && cmds_sent)
431                 packet_flush(out);
432
433         if (status_report && cmds_sent)
434                 ret = receive_status(in, remote_refs);
435         else
436                 ret = 0;
437         if (args->stateless_rpc)
438                 packet_flush(out);
439
440         if (use_sideband && cmds_sent) {
441                 if (finish_async(&demux)) {
442                         error("error in sideband demultiplexer");
443                         ret = -1;
444                 }
445                 close(demux.out);
446         }
447
448         if (ret < 0)
449                 return ret;
450
451         if (args->porcelain)
452                 return 0;
453
454         for (ref = remote_refs; ref; ref = ref->next) {
455                 switch (ref->status) {
456                 case REF_STATUS_NONE:
457                 case REF_STATUS_UPTODATE:
458                 case REF_STATUS_OK:
459                         break;
460                 default:
461                         return -1;
462                 }
463         }
464         return 0;
465 }