Merge branch 'lj/refs'
[git/git.git] / upload-pack.c
1 #include <signal.h>
2 #include <sys/wait.h>
3 #include <sys/poll.h>
4 #include "cache.h"
5 #include "refs.h"
6 #include "pkt-line.h"
7 #include "sideband.h"
8 #include "tag.h"
9 #include "object.h"
10 #include "commit.h"
11 #include "exec_cmd.h"
12
13 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
14
15 #define THEY_HAVE (1U << 0)
16 #define OUR_REF (1U << 1)
17 #define WANTED (1U << 2)
18 static int multi_ack, nr_our_refs;
19 static int use_thin_pack, use_ofs_delta;
20 static struct object_array have_obj;
21 static struct object_array want_obj;
22 static unsigned int timeout;
23 /* 0 for no sideband,
24 * otherwise maximum packet size (up to 65520 bytes).
25 */
26 static int use_sideband;
27
28 static void reset_timeout(void)
29 {
30 alarm(timeout);
31 }
32
33 static int strip(char *line, int len)
34 {
35 if (len && line[len-1] == '\n')
36 line[--len] = 0;
37 return len;
38 }
39
40 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
41 {
42 if (use_sideband)
43 return send_sideband(1, fd, data, sz, use_sideband);
44 if (fd == 3)
45 /* emergency quit */
46 fd = 2;
47 if (fd == 2) {
48 xwrite(fd, data, sz);
49 return sz;
50 }
51 return safe_write(fd, data, sz);
52 }
53
54 static void create_pack_file(void)
55 {
56 /* Pipes between rev-list to pack-objects, pack-objects to us
57 * and pack-objects error stream for progress bar.
58 */
59 int lp_pipe[2], pu_pipe[2], pe_pipe[2];
60 pid_t pid_rev_list, pid_pack_objects;
61 int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
62 char data[8193], progress[128];
63 char abort_msg[] = "aborting due to possible repository "
64 "corruption on the remote side.";
65 int buffered = -1;
66
67 if (pipe(lp_pipe) < 0)
68 die("git-upload-pack: unable to create pipe");
69 pid_rev_list = fork();
70 if (pid_rev_list < 0)
71 die("git-upload-pack: unable to fork git-rev-list");
72
73 if (!pid_rev_list) {
74 int i;
75 int args;
76 const char **argv;
77 const char **p;
78 char *buf;
79
80 if (create_full_pack) {
81 args = 10;
82 use_thin_pack = 0; /* no point doing it */
83 }
84 else
85 args = have_obj.nr + want_obj.nr + 5;
86 p = xmalloc(args * sizeof(char *));
87 argv = (const char **) p;
88 buf = xmalloc(args * 45);
89
90 dup2(lp_pipe[1], 1);
91 close(0);
92 close(lp_pipe[0]);
93 close(lp_pipe[1]);
94 *p++ = "rev-list";
95 *p++ = use_thin_pack ? "--objects-edge" : "--objects";
96 if (create_full_pack)
97 *p++ = "--all";
98 else {
99 for (i = 0; i < want_obj.nr; i++) {
100 struct object *o = want_obj.objects[i].item;
101 *p++ = buf;
102 memcpy(buf, sha1_to_hex(o->sha1), 41);
103 buf += 41;
104 }
105 }
106 if (!create_full_pack)
107 for (i = 0; i < have_obj.nr; i++) {
108 struct object *o = have_obj.objects[i].item;
109 *p++ = buf;
110 *buf++ = '^';
111 memcpy(buf, sha1_to_hex(o->sha1), 41);
112 buf += 41;
113 }
114 *p++ = NULL;
115 execv_git_cmd(argv);
116 die("git-upload-pack: unable to exec git-rev-list");
117 }
118
119 if (pipe(pu_pipe) < 0)
120 die("git-upload-pack: unable to create pipe");
121 if (pipe(pe_pipe) < 0)
122 die("git-upload-pack: unable to create pipe");
123 pid_pack_objects = fork();
124 if (pid_pack_objects < 0) {
125 /* daemon sets things up to ignore TERM */
126 kill(pid_rev_list, SIGKILL);
127 die("git-upload-pack: unable to fork git-pack-objects");
128 }
129 if (!pid_pack_objects) {
130 dup2(lp_pipe[0], 0);
131 dup2(pu_pipe[1], 1);
132 dup2(pe_pipe[1], 2);
133
134 close(lp_pipe[0]);
135 close(lp_pipe[1]);
136 close(pu_pipe[0]);
137 close(pu_pipe[1]);
138 close(pe_pipe[0]);
139 close(pe_pipe[1]);
140 execl_git_cmd("pack-objects", "--stdout", "--progress",
141 use_ofs_delta ? "--delta-base-offset" : NULL,
142 NULL);
143 kill(pid_rev_list, SIGKILL);
144 die("git-upload-pack: unable to exec git-pack-objects");
145 }
146
147 close(lp_pipe[0]);
148 close(lp_pipe[1]);
149
150 /* We read from pe_pipe[0] to capture stderr output for
151 * progress bar, and pu_pipe[0] to capture the pack data.
152 */
153 close(pe_pipe[1]);
154 close(pu_pipe[1]);
155
156 while (1) {
157 const char *who;
158 struct pollfd pfd[2];
159 pid_t pid;
160 int status;
161 ssize_t sz;
162 int pe, pu, pollsize;
163
164 reset_timeout();
165
166 pollsize = 0;
167 pe = pu = -1;
168
169 if (0 <= pu_pipe[0]) {
170 pfd[pollsize].fd = pu_pipe[0];
171 pfd[pollsize].events = POLLIN;
172 pu = pollsize;
173 pollsize++;
174 }
175 if (0 <= pe_pipe[0]) {
176 pfd[pollsize].fd = pe_pipe[0];
177 pfd[pollsize].events = POLLIN;
178 pe = pollsize;
179 pollsize++;
180 }
181
182 if (pollsize) {
183 if (poll(pfd, pollsize, -1) < 0) {
184 if (errno != EINTR) {
185 error("poll failed, resuming: %s",
186 strerror(errno));
187 sleep(1);
188 }
189 continue;
190 }
191 if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
192 /* Data ready; we keep the last byte
193 * to ourselves in case we detect
194 * broken rev-list, so that we can
195 * leave the stream corrupted. This
196 * is unfortunate -- unpack-objects
197 * would happily accept a valid pack
198 * data with trailing garbage, so
199 * appending garbage after we pass all
200 * the pack data is not good enough to
201 * signal breakage to downstream.
202 */
203 char *cp = data;
204 ssize_t outsz = 0;
205 if (0 <= buffered) {
206 *cp++ = buffered;
207 outsz++;
208 }
209 sz = read(pu_pipe[0], cp,
210 sizeof(data) - outsz);
211 if (0 < sz)
212 ;
213 else if (sz == 0) {
214 close(pu_pipe[0]);
215 pu_pipe[0] = -1;
216 }
217 else
218 goto fail;
219 sz += outsz;
220 if (1 < sz) {
221 buffered = data[sz-1] & 0xFF;
222 sz--;
223 }
224 else
225 buffered = -1;
226 sz = send_client_data(1, data, sz);
227 if (sz < 0)
228 goto fail;
229 }
230 if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
231 /* Status ready; we ship that in the side-band
232 * or dump to the standard error.
233 */
234 sz = read(pe_pipe[0], progress,
235 sizeof(progress));
236 if (0 < sz)
237 send_client_data(2, progress, sz);
238 else if (sz == 0) {
239 close(pe_pipe[0]);
240 pe_pipe[0] = -1;
241 }
242 else
243 goto fail;
244 }
245 }
246
247 /* See if the children are still there */
248 if (pid_rev_list || pid_pack_objects) {
249 pid = waitpid(-1, &status, WNOHANG);
250 if (!pid)
251 continue;
252 who = ((pid == pid_rev_list) ? "git-rev-list" :
253 (pid == pid_pack_objects) ? "git-pack-objects" :
254 NULL);
255 if (!who) {
256 if (pid < 0) {
257 error("git-upload-pack: %s",
258 strerror(errno));
259 goto fail;
260 }
261 error("git-upload-pack: we weren't "
262 "waiting for %d", pid);
263 continue;
264 }
265 if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
266 error("git-upload-pack: %s died with error.",
267 who);
268 goto fail;
269 }
270 if (pid == pid_rev_list)
271 pid_rev_list = 0;
272 if (pid == pid_pack_objects)
273 pid_pack_objects = 0;
274 if (pid_rev_list || pid_pack_objects)
275 continue;
276 }
277
278 /* both died happily */
279 if (pollsize)
280 continue;
281
282 /* flush the data */
283 if (0 <= buffered) {
284 data[0] = buffered;
285 sz = send_client_data(1, data, 1);
286 if (sz < 0)
287 goto fail;
288 fprintf(stderr, "flushed.\n");
289 }
290 if (use_sideband)
291 packet_flush(1);
292 return;
293 }
294 fail:
295 if (pid_pack_objects)
296 kill(pid_pack_objects, SIGKILL);
297 if (pid_rev_list)
298 kill(pid_rev_list, SIGKILL);
299 send_client_data(3, abort_msg, sizeof(abort_msg));
300 die("git-upload-pack: %s", abort_msg);
301 }
302
303 static int got_sha1(char *hex, unsigned char *sha1)
304 {
305 struct object *o;
306
307 if (get_sha1_hex(hex, sha1))
308 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
309 if (!has_sha1_file(sha1))
310 return 0;
311
312 o = lookup_object(sha1);
313 if (!(o && o->parsed))
314 o = parse_object(sha1);
315 if (!o)
316 die("oops (%s)", sha1_to_hex(sha1));
317 if (o->type == OBJ_COMMIT) {
318 struct commit_list *parents;
319 if (o->flags & THEY_HAVE)
320 return 0;
321 o->flags |= THEY_HAVE;
322 for (parents = ((struct commit*)o)->parents;
323 parents;
324 parents = parents->next)
325 parents->item->object.flags |= THEY_HAVE;
326 }
327 add_object_array(o, NULL, &have_obj);
328 return 1;
329 }
330
331 static int get_common_commits(void)
332 {
333 static char line[1000];
334 unsigned char sha1[20];
335 char hex[41], last_hex[41];
336 int len;
337
338 track_object_refs = 0;
339 save_commit_buffer = 0;
340
341 for(;;) {
342 len = packet_read_line(0, line, sizeof(line));
343 reset_timeout();
344
345 if (!len) {
346 if (have_obj.nr == 0 || multi_ack)
347 packet_write(1, "NAK\n");
348 continue;
349 }
350 len = strip(line, len);
351 if (!strncmp(line, "have ", 5)) {
352 if (got_sha1(line+5, sha1)) {
353 memcpy(hex, sha1_to_hex(sha1), 41);
354 if (multi_ack) {
355 const char *msg = "ACK %s continue\n";
356 packet_write(1, msg, hex);
357 memcpy(last_hex, hex, 41);
358 }
359 else if (have_obj.nr == 1)
360 packet_write(1, "ACK %s\n", hex);
361 }
362 continue;
363 }
364 if (!strcmp(line, "done")) {
365 if (have_obj.nr > 0) {
366 if (multi_ack)
367 packet_write(1, "ACK %s\n", last_hex);
368 return 0;
369 }
370 packet_write(1, "NAK\n");
371 return -1;
372 }
373 die("git-upload-pack: expected SHA1 list, got '%s'", line);
374 }
375 }
376
377 static void receive_needs(void)
378 {
379 static char line[1000];
380 int len;
381
382 for (;;) {
383 struct object *o;
384 unsigned char sha1_buf[20];
385 len = packet_read_line(0, line, sizeof(line));
386 reset_timeout();
387 if (!len)
388 return;
389
390 if (strncmp("want ", line, 5) ||
391 get_sha1_hex(line+5, sha1_buf))
392 die("git-upload-pack: protocol error, "
393 "expected to get sha, not '%s'", line);
394 if (strstr(line+45, "multi_ack"))
395 multi_ack = 1;
396 if (strstr(line+45, "thin-pack"))
397 use_thin_pack = 1;
398 if (strstr(line+45, "ofs-delta"))
399 use_ofs_delta = 1;
400 if (strstr(line+45, "side-band-64k"))
401 use_sideband = LARGE_PACKET_MAX;
402 else if (strstr(line+45, "side-band"))
403 use_sideband = DEFAULT_PACKET_MAX;
404
405 /* We have sent all our refs already, and the other end
406 * should have chosen out of them; otherwise they are
407 * asking for nonsense.
408 *
409 * Hmph. We may later want to allow "want" line that
410 * asks for something like "master~10" (symbolic)...
411 * would it make sense? I don't know.
412 */
413 o = lookup_object(sha1_buf);
414 if (!o || !(o->flags & OUR_REF))
415 die("git-upload-pack: not our ref %s", line+5);
416 if (!(o->flags & WANTED)) {
417 o->flags |= WANTED;
418 add_object_array(o, NULL, &want_obj);
419 }
420 }
421 }
422
423 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
424 {
425 static const char *capabilities = "multi_ack thin-pack side-band side-band-64k ofs-delta";
426 struct object *o = parse_object(sha1);
427
428 if (!o)
429 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
430
431 if (capabilities)
432 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
433 0, capabilities);
434 else
435 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
436 capabilities = NULL;
437 if (!(o->flags & OUR_REF)) {
438 o->flags |= OUR_REF;
439 nr_our_refs++;
440 }
441 if (o->type == OBJ_TAG) {
442 o = deref_tag(o, refname, 0);
443 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
444 }
445 return 0;
446 }
447
448 static void upload_pack(void)
449 {
450 reset_timeout();
451 head_ref(send_ref, NULL);
452 for_each_ref(send_ref, NULL);
453 packet_flush(1);
454 receive_needs();
455 if (want_obj.nr) {
456 get_common_commits();
457 create_pack_file();
458 }
459 }
460
461 int main(int argc, char **argv)
462 {
463 char *dir;
464 int i;
465 int strict = 0;
466
467 for (i = 1; i < argc; i++) {
468 char *arg = argv[i];
469
470 if (arg[0] != '-')
471 break;
472 if (!strcmp(arg, "--strict")) {
473 strict = 1;
474 continue;
475 }
476 if (!strncmp(arg, "--timeout=", 10)) {
477 timeout = atoi(arg+10);
478 continue;
479 }
480 if (!strcmp(arg, "--")) {
481 i++;
482 break;
483 }
484 }
485
486 if (i != argc-1)
487 usage(upload_pack_usage);
488 dir = argv[i];
489
490 if (!enter_repo(dir, strict))
491 die("'%s': unable to chdir or not a git archive", dir);
492
493 upload_pack();
494 return 0;
495 }