35c7ecb7b4efabc700dc22bfe76617be1ea38b4a
[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 "tag.h"
8 #include "object.h"
9 #include "commit.h"
10 #include "exec_cmd.h"
11
12 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
13
14 #define THEY_HAVE (1U << 0)
15 #define OUR_REF (1U << 1)
16 #define WANTED (1U << 2)
17 static int multi_ack = 0, nr_our_refs = 0;
18 static int use_thin_pack = 0;
19 static struct object_array have_obj;
20 static struct object_array want_obj;
21 static unsigned int timeout = 0;
22 static int use_sideband = 0;
23
24 static void reset_timeout(void)
25 {
26 alarm(timeout);
27 }
28
29 static int strip(char *line, int len)
30 {
31 if (len && line[len-1] == '\n')
32 line[--len] = 0;
33 return len;
34 }
35
36 #define PACKET_MAX 1000
37 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
38 {
39 ssize_t ssz;
40 const char *p;
41
42 if (!data) {
43 if (!use_sideband)
44 return 0;
45 packet_flush(1);
46 }
47
48 if (!use_sideband) {
49 if (fd == 3)
50 /* emergency quit */
51 fd = 2;
52 if (fd == 2) {
53 xwrite(fd, data, sz);
54 return sz;
55 }
56 return safe_write(fd, data, sz);
57 }
58 p = data;
59 ssz = sz;
60 while (sz) {
61 unsigned n;
62 char hdr[5];
63
64 n = sz;
65 if (PACKET_MAX - 5 < n)
66 n = PACKET_MAX - 5;
67 sprintf(hdr, "%04x", n + 5);
68 hdr[4] = fd;
69 safe_write(1, hdr, 5);
70 safe_write(1, p, n);
71 p += n;
72 sz -= n;
73 }
74 return ssz;
75 }
76
77 static void create_pack_file(void)
78 {
79 /* Pipes between rev-list to pack-objects, pack-objects to us
80 * and pack-objects error stream for progress bar.
81 */
82 int lp_pipe[2], pu_pipe[2], pe_pipe[2];
83 pid_t pid_rev_list, pid_pack_objects;
84 int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
85 char data[8193], progress[128];
86 char abort_msg[] = "aborting due to possible repository "
87 "corruption on the remote side.";
88 int buffered = -1;
89
90 if (pipe(lp_pipe) < 0)
91 die("git-upload-pack: unable to create pipe");
92 pid_rev_list = fork();
93 if (pid_rev_list < 0)
94 die("git-upload-pack: unable to fork git-rev-list");
95
96 if (!pid_rev_list) {
97 int i;
98 int args;
99 const char **argv;
100 const char **p;
101 char *buf;
102
103 if (create_full_pack) {
104 args = 10;
105 use_thin_pack = 0; /* no point doing it */
106 }
107 else
108 args = have_obj.nr + want_obj.nr + 5;
109 p = xmalloc(args * sizeof(char *));
110 argv = (const char **) p;
111 buf = xmalloc(args * 45);
112
113 dup2(lp_pipe[1], 1);
114 close(0);
115 close(lp_pipe[0]);
116 close(lp_pipe[1]);
117 *p++ = "rev-list";
118 *p++ = use_thin_pack ? "--objects-edge" : "--objects";
119 if (create_full_pack)
120 *p++ = "--all";
121 else {
122 for (i = 0; i < want_obj.nr; i++) {
123 struct object *o = want_obj.objects[i].item;
124 *p++ = buf;
125 memcpy(buf, sha1_to_hex(o->sha1), 41);
126 buf += 41;
127 }
128 }
129 if (!create_full_pack)
130 for (i = 0; i < have_obj.nr; i++) {
131 struct object *o = have_obj.objects[i].item;
132 *p++ = buf;
133 *buf++ = '^';
134 memcpy(buf, sha1_to_hex(o->sha1), 41);
135 buf += 41;
136 }
137 *p++ = NULL;
138 execv_git_cmd(argv);
139 die("git-upload-pack: unable to exec git-rev-list");
140 }
141
142 if (pipe(pu_pipe) < 0)
143 die("git-upload-pack: unable to create pipe");
144 if (pipe(pe_pipe) < 0)
145 die("git-upload-pack: unable to create pipe");
146 pid_pack_objects = fork();
147 if (pid_pack_objects < 0) {
148 /* daemon sets things up to ignore TERM */
149 kill(pid_rev_list, SIGKILL);
150 die("git-upload-pack: unable to fork git-pack-objects");
151 }
152 if (!pid_pack_objects) {
153 dup2(lp_pipe[0], 0);
154 dup2(pu_pipe[1], 1);
155 dup2(pe_pipe[1], 2);
156
157 close(lp_pipe[0]);
158 close(lp_pipe[1]);
159 close(pu_pipe[0]);
160 close(pu_pipe[1]);
161 close(pe_pipe[0]);
162 close(pe_pipe[1]);
163 execl_git_cmd("pack-objects", "--stdout", "--progress", NULL);
164 kill(pid_rev_list, SIGKILL);
165 die("git-upload-pack: unable to exec git-pack-objects");
166 }
167
168 close(lp_pipe[0]);
169 close(lp_pipe[1]);
170
171 /* We read from pe_pipe[0] to capture stderr output for
172 * progress bar, and pu_pipe[0] to capture the pack data.
173 */
174 close(pe_pipe[1]);
175 close(pu_pipe[1]);
176
177 while (1) {
178 const char *who;
179 struct pollfd pfd[2];
180 pid_t pid;
181 int status;
182 ssize_t sz;
183 int pe, pu, pollsize;
184
185 reset_timeout();
186
187 pollsize = 0;
188 pe = pu = -1;
189
190 if (0 <= pu_pipe[0]) {
191 pfd[pollsize].fd = pu_pipe[0];
192 pfd[pollsize].events = POLLIN;
193 pu = pollsize;
194 pollsize++;
195 }
196 if (0 <= pe_pipe[0]) {
197 pfd[pollsize].fd = pe_pipe[0];
198 pfd[pollsize].events = POLLIN;
199 pe = pollsize;
200 pollsize++;
201 }
202
203 if (pollsize) {
204 if (poll(pfd, pollsize, -1) < 0) {
205 if (errno != EINTR) {
206 error("poll failed, resuming: %s",
207 strerror(errno));
208 sleep(1);
209 }
210 continue;
211 }
212 if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
213 /* Data ready; we keep the last byte
214 * to ourselves in case we detect
215 * broken rev-list, so that we can
216 * leave the stream corrupted. This
217 * is unfortunate -- unpack-objects
218 * would happily accept a valid pack
219 * data with trailing garbage, so
220 * appending garbage after we pass all
221 * the pack data is not good enough to
222 * signal breakage to downstream.
223 */
224 char *cp = data;
225 ssize_t outsz = 0;
226 if (0 <= buffered) {
227 *cp++ = buffered;
228 outsz++;
229 }
230 sz = read(pu_pipe[0], cp,
231 sizeof(data) - outsz);
232 if (0 < sz)
233 ;
234 else if (sz == 0) {
235 close(pu_pipe[0]);
236 pu_pipe[0] = -1;
237 }
238 else
239 goto fail;
240 sz += outsz;
241 if (1 < sz) {
242 buffered = data[sz-1] & 0xFF;
243 sz--;
244 }
245 else
246 buffered = -1;
247 sz = send_client_data(1, data, sz);
248 if (sz < 0)
249 goto fail;
250 }
251 if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
252 /* Status ready; we ship that in the side-band
253 * or dump to the standard error.
254 */
255 sz = read(pe_pipe[0], progress,
256 sizeof(progress));
257 if (0 < sz)
258 send_client_data(2, progress, sz);
259 else if (sz == 0) {
260 close(pe_pipe[0]);
261 pe_pipe[0] = -1;
262 }
263 else
264 goto fail;
265 }
266 }
267
268 /* See if the children are still there */
269 if (pid_rev_list || pid_pack_objects) {
270 pid = waitpid(-1, &status, WNOHANG);
271 if (!pid)
272 continue;
273 who = ((pid == pid_rev_list) ? "git-rev-list" :
274 (pid == pid_pack_objects) ? "git-pack-objects" :
275 NULL);
276 if (!who) {
277 if (pid < 0) {
278 error("git-upload-pack: %s",
279 strerror(errno));
280 goto fail;
281 }
282 error("git-upload-pack: we weren't "
283 "waiting for %d", pid);
284 continue;
285 }
286 if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
287 error("git-upload-pack: %s died with error.",
288 who);
289 goto fail;
290 }
291 if (pid == pid_rev_list)
292 pid_rev_list = 0;
293 if (pid == pid_pack_objects)
294 pid_pack_objects = 0;
295 if (pid_rev_list || pid_pack_objects)
296 continue;
297 }
298
299 /* both died happily */
300 if (pollsize)
301 continue;
302
303 /* flush the data */
304 if (0 <= buffered) {
305 data[0] = buffered;
306 sz = send_client_data(1, data, 1);
307 if (sz < 0)
308 goto fail;
309 fprintf(stderr, "flushed.\n");
310 }
311 send_client_data(1, NULL, 0);
312 return;
313 }
314 fail:
315 if (pid_pack_objects)
316 kill(pid_pack_objects, SIGKILL);
317 if (pid_rev_list)
318 kill(pid_rev_list, SIGKILL);
319 send_client_data(3, abort_msg, sizeof(abort_msg));
320 die("git-upload-pack: %s", abort_msg);
321 }
322
323 static int got_sha1(char *hex, unsigned char *sha1)
324 {
325 struct object *o;
326
327 if (get_sha1_hex(hex, sha1))
328 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
329 if (!has_sha1_file(sha1))
330 return 0;
331
332 o = lookup_object(sha1);
333 if (!(o && o->parsed))
334 o = parse_object(sha1);
335 if (!o)
336 die("oops (%s)", sha1_to_hex(sha1));
337 if (o->type == OBJ_COMMIT) {
338 struct commit_list *parents;
339 if (o->flags & THEY_HAVE)
340 return 0;
341 o->flags |= THEY_HAVE;
342 for (parents = ((struct commit*)o)->parents;
343 parents;
344 parents = parents->next)
345 parents->item->object.flags |= THEY_HAVE;
346 }
347 add_object_array(o, NULL, &have_obj);
348 return 1;
349 }
350
351 static int get_common_commits(void)
352 {
353 static char line[1000];
354 unsigned char sha1[20];
355 char hex[41], last_hex[41];
356 int len;
357
358 track_object_refs = 0;
359 save_commit_buffer = 0;
360
361 for(;;) {
362 len = packet_read_line(0, line, sizeof(line));
363 reset_timeout();
364
365 if (!len) {
366 if (have_obj.nr == 0 || multi_ack)
367 packet_write(1, "NAK\n");
368 continue;
369 }
370 len = strip(line, len);
371 if (!strncmp(line, "have ", 5)) {
372 if (got_sha1(line+5, sha1)) {
373 memcpy(hex, sha1_to_hex(sha1), 41);
374 if (multi_ack) {
375 const char *msg = "ACK %s continue\n";
376 packet_write(1, msg, hex);
377 memcpy(last_hex, hex, 41);
378 }
379 else if (have_obj.nr == 1)
380 packet_write(1, "ACK %s\n", hex);
381 }
382 continue;
383 }
384 if (!strcmp(line, "done")) {
385 if (have_obj.nr > 0) {
386 if (multi_ack)
387 packet_write(1, "ACK %s\n", last_hex);
388 return 0;
389 }
390 packet_write(1, "NAK\n");
391 return -1;
392 }
393 die("git-upload-pack: expected SHA1 list, got '%s'", line);
394 }
395 }
396
397 static void receive_needs(void)
398 {
399 static char line[1000];
400 int len;
401
402 for (;;) {
403 struct object *o;
404 unsigned char sha1_buf[20];
405 len = packet_read_line(0, line, sizeof(line));
406 reset_timeout();
407 if (!len)
408 return;
409
410 if (strncmp("want ", line, 5) ||
411 get_sha1_hex(line+5, sha1_buf))
412 die("git-upload-pack: protocol error, "
413 "expected to get sha, not '%s'", line);
414 if (strstr(line+45, "multi_ack"))
415 multi_ack = 1;
416 if (strstr(line+45, "thin-pack"))
417 use_thin_pack = 1;
418 if (strstr(line+45, "side-band"))
419 use_sideband = 1;
420
421 /* We have sent all our refs already, and the other end
422 * should have chosen out of them; otherwise they are
423 * asking for nonsense.
424 *
425 * Hmph. We may later want to allow "want" line that
426 * asks for something like "master~10" (symbolic)...
427 * would it make sense? I don't know.
428 */
429 o = lookup_object(sha1_buf);
430 if (!o || !(o->flags & OUR_REF))
431 die("git-upload-pack: not our ref %s", line+5);
432 if (!(o->flags & WANTED)) {
433 o->flags |= WANTED;
434 add_object_array(o, NULL, &want_obj);
435 }
436 }
437 }
438
439 static int send_ref(const char *refname, const unsigned char *sha1)
440 {
441 static const char *capabilities = "multi_ack thin-pack side-band";
442 struct object *o = parse_object(sha1);
443
444 if (!o)
445 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
446
447 if (capabilities)
448 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
449 0, capabilities);
450 else
451 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
452 capabilities = NULL;
453 if (!(o->flags & OUR_REF)) {
454 o->flags |= OUR_REF;
455 nr_our_refs++;
456 }
457 if (o->type == OBJ_TAG) {
458 o = deref_tag(o, refname, 0);
459 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
460 }
461 return 0;
462 }
463
464 static int upload_pack(void)
465 {
466 reset_timeout();
467 head_ref(send_ref);
468 for_each_ref(send_ref);
469 packet_flush(1);
470 receive_needs();
471 if (!want_obj.nr)
472 return 0;
473 get_common_commits();
474 create_pack_file();
475 return 0;
476 }
477
478 int main(int argc, char **argv)
479 {
480 char *dir;
481 int i;
482 int strict = 0;
483
484 for (i = 1; i < argc; i++) {
485 char *arg = argv[i];
486
487 if (arg[0] != '-')
488 break;
489 if (!strcmp(arg, "--strict")) {
490 strict = 1;
491 continue;
492 }
493 if (!strncmp(arg, "--timeout=", 10)) {
494 timeout = atoi(arg+10);
495 continue;
496 }
497 if (!strcmp(arg, "--")) {
498 i++;
499 break;
500 }
501 }
502
503 if (i != argc-1)
504 usage(upload_pack_usage);
505 dir = argv[i];
506
507 if (!enter_repo(dir, strict))
508 die("'%s': unable to chdir or not a git archive", dir);
509
510 upload_pack();
511 return 0;
512 }