push: the beginning of "git push --signed"
[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 void generate_push_cert(struct strbuf *req_buf,
229                                const struct ref *remote_refs,
230                                struct send_pack_args *args)
231 {
232         const struct ref *ref;
233         char stamp[60];
234         char *signing_key = xstrdup(get_signing_key());
235         const char *cp, *np;
236         struct strbuf cert = STRBUF_INIT;
237         int update_seen = 0;
238
239         datestamp(stamp, sizeof(stamp));
240         strbuf_addf(&cert, "certificate version 0.1\n");
241         strbuf_addf(&cert, "pusher %s %s\n", signing_key, stamp);
242         strbuf_addstr(&cert, "\n");
243
244         for (ref = remote_refs; ref; ref = ref->next) {
245                 if (!ref_update_to_be_sent(ref, args))
246                         continue;
247                 update_seen = 1;
248                 strbuf_addf(&cert, "%s %s %s\n",
249                             sha1_to_hex(ref->old_sha1),
250                             sha1_to_hex(ref->new_sha1),
251                             ref->name);
252         }
253         if (!update_seen)
254                 goto free_return;
255
256         if (sign_buffer(&cert, &cert, signing_key))
257                 die(_("failed to sign the push certificate"));
258
259         packet_buf_write(req_buf, "push-cert\n");
260         for (cp = cert.buf; cp < cert.buf + cert.len; cp = np) {
261                 np = next_line(cp, cert.buf + cert.len - cp);
262                 packet_buf_write(req_buf,
263                                  "%.*s", (int)(np - cp), cp);
264         }
265         packet_buf_write(req_buf, "push-cert-end\n");
266
267 free_return:
268         free(signing_key);
269         strbuf_release(&cert);
270 }
271
272 int send_pack(struct send_pack_args *args,
273               int fd[], struct child_process *conn,
274               struct ref *remote_refs,
275               struct sha1_array *extra_have)
276 {
277         int in = fd[0];
278         int out = fd[1];
279         struct strbuf req_buf = STRBUF_INIT;
280         struct strbuf cap_buf = STRBUF_INIT;
281         struct ref *ref;
282         int need_pack_data = 0;
283         int allow_deleting_refs = 0;
284         int status_report = 0;
285         int use_sideband = 0;
286         int quiet_supported = 0;
287         int agent_supported = 0;
288         unsigned cmds_sent = 0;
289         int ret;
290         struct async demux;
291
292         /* Does the other end support the reporting? */
293         if (server_supports("report-status"))
294                 status_report = 1;
295         if (server_supports("delete-refs"))
296                 allow_deleting_refs = 1;
297         if (server_supports("ofs-delta"))
298                 args->use_ofs_delta = 1;
299         if (server_supports("side-band-64k"))
300                 use_sideband = 1;
301         if (server_supports("quiet"))
302                 quiet_supported = 1;
303         if (server_supports("agent"))
304                 agent_supported = 1;
305         if (server_supports("no-thin"))
306                 args->use_thin_pack = 0;
307         if (args->push_cert && !server_supports("push-cert"))
308                 die(_("the receiving end does not support --signed push"));
309
310         if (!remote_refs) {
311                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
312                         "Perhaps you should specify a branch such as 'master'.\n");
313                 return 0;
314         }
315
316         if (status_report)
317                 strbuf_addstr(&cap_buf, " report-status");
318         if (use_sideband)
319                 strbuf_addstr(&cap_buf, " side-band-64k");
320         if (quiet_supported && (args->quiet || !args->progress))
321                 strbuf_addstr(&cap_buf, " quiet");
322         if (agent_supported)
323                 strbuf_addf(&cap_buf, " agent=%s", git_user_agent_sanitized());
324
325         /*
326          * NEEDSWORK: why does delete-refs have to be so specific to
327          * send-pack machinery that set_ref_status_for_push() cannot
328          * set this bit for us???
329          */
330         for (ref = remote_refs; ref; ref = ref->next)
331                 if (ref->deletion && !allow_deleting_refs)
332                         ref->status = REF_STATUS_REJECT_NODELETE;
333
334         if (!args->dry_run)
335                 advertise_shallow_grafts_buf(&req_buf);
336
337         if (!args->dry_run && args->push_cert)
338                 generate_push_cert(&req_buf, remote_refs, args);
339
340         /*
341          * Clear the status for each ref and see if we need to send
342          * the pack data.
343          */
344         for (ref = remote_refs; ref; ref = ref->next) {
345                 if (!ref_update_to_be_sent(ref, args))
346                         continue;
347
348                 if (!ref->deletion)
349                         need_pack_data = 1;
350
351                 if (args->dry_run || !status_report)
352                         ref->status = REF_STATUS_OK;
353                 else
354                         ref->status = REF_STATUS_EXPECTING_REPORT;
355         }
356
357         /*
358          * Finally, tell the other end!
359          */
360         for (ref = remote_refs; ref; ref = ref->next) {
361                 char *old_hex, *new_hex;
362
363                 if (args->dry_run)
364                         continue;
365
366                 if (!ref_update_to_be_sent(ref, args))
367                         continue;
368
369                 old_hex = sha1_to_hex(ref->old_sha1);
370                 new_hex = sha1_to_hex(ref->new_sha1);
371                 if (!cmds_sent) {
372                         packet_buf_write(&req_buf,
373                                          "%s %s %s%c%s",
374                                          old_hex, new_hex, ref->name, 0,
375                                          cap_buf.buf);
376                         cmds_sent = 1;
377                 } else {
378                         packet_buf_write(&req_buf, "%s %s %s",
379                                          old_hex, new_hex, ref->name);
380                 }
381         }
382
383         if (args->stateless_rpc) {
384                 if (!args->dry_run && (cmds_sent || is_repository_shallow())) {
385                         packet_buf_flush(&req_buf);
386                         send_sideband(out, -1, req_buf.buf, req_buf.len, LARGE_PACKET_MAX);
387                 }
388         } else {
389                 write_or_die(out, req_buf.buf, req_buf.len);
390                 packet_flush(out);
391         }
392         strbuf_release(&req_buf);
393         strbuf_release(&cap_buf);
394
395         if (use_sideband && cmds_sent) {
396                 memset(&demux, 0, sizeof(demux));
397                 demux.proc = sideband_demux;
398                 demux.data = fd;
399                 demux.out = -1;
400                 if (start_async(&demux))
401                         die("send-pack: unable to fork off sideband demultiplexer");
402                 in = demux.out;
403         }
404
405         if (need_pack_data && cmds_sent) {
406                 if (pack_objects(out, remote_refs, extra_have, args) < 0) {
407                         for (ref = remote_refs; ref; ref = ref->next)
408                                 ref->status = REF_STATUS_NONE;
409                         if (args->stateless_rpc)
410                                 close(out);
411                         if (git_connection_is_socket(conn))
412                                 shutdown(fd[0], SHUT_WR);
413                         if (use_sideband)
414                                 finish_async(&demux);
415                         fd[1] = -1;
416                         return -1;
417                 }
418                 if (!args->stateless_rpc)
419                         /* Closed by pack_objects() via start_command() */
420                         fd[1] = -1;
421         }
422         if (args->stateless_rpc && cmds_sent)
423                 packet_flush(out);
424
425         if (status_report && cmds_sent)
426                 ret = receive_status(in, remote_refs);
427         else
428                 ret = 0;
429         if (args->stateless_rpc)
430                 packet_flush(out);
431
432         if (use_sideband && cmds_sent) {
433                 if (finish_async(&demux)) {
434                         error("error in sideband demultiplexer");
435                         ret = -1;
436                 }
437                 close(demux.out);
438         }
439
440         if (ret < 0)
441                 return ret;
442
443         if (args->porcelain)
444                 return 0;
445
446         for (ref = remote_refs; ref; ref = ref->next) {
447                 switch (ref->status) {
448                 case REF_STATUS_NONE:
449                 case REF_STATUS_UPTODATE:
450                 case REF_STATUS_OK:
451                         break;
452                 default:
453                         return -1;
454                 }
455         }
456         return 0;
457 }