Merge branch 'ew/rebase' into next
[git] / upload-pack.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "pkt-line.h"
4 #include "tag.h"
5 #include "object.h"
6 #include "commit.h"
7 #include "exec_cmd.h"
8 #include <signal.h>
9 #include <sys/poll.h>
10 #include <sys/wait.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 #define MAX_HAS 256
18 #define MAX_NEEDS 256
19 static int nr_has = 0, nr_needs = 0, multi_ack = 0, nr_our_refs = 0;
20 static int use_thin_pack = 0;
21 static unsigned char has_sha1[MAX_HAS][20];
22 static unsigned char needs_sha1[MAX_NEEDS][20];
23 static unsigned int timeout = 0;
24 static int use_sideband = 0;
25
26 static void reset_timeout(void)
27 {
28         alarm(timeout);
29 }
30
31 static int strip(char *line, int len)
32 {
33         if (len && line[len-1] == '\n')
34                 line[--len] = 0;
35         return len;
36 }
37
38 #define PACKET_MAX 1000
39 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
40 {
41         ssize_t ssz;
42         const char *p;
43
44         if (!data) {
45                 if (!use_sideband)
46                         return 0;
47                 packet_flush(1);
48         }
49
50         if (!use_sideband) {
51                 if (fd == 3)
52                         /* emergency quit */
53                         fd = 2;
54                 return safe_write(fd, data, sz);
55         }
56         p = data;
57         ssz = sz;
58         while (sz) {
59                 unsigned n;
60                 char hdr[5];
61
62                 n = sz;
63                 if (PACKET_MAX - 5 < n)
64                         n = PACKET_MAX - 5;
65                 sprintf(hdr, "%04x", n + 5);
66                 hdr[4] = fd;
67                 safe_write(1, hdr, 5);
68                 safe_write(1, p, n);
69                 p += n;
70                 sz -= n;
71         }
72         return ssz;
73 }
74
75 static void create_pack_file(void)
76 {
77         /* Pipes between rev-list to pack-objects, pack-objects to us
78          * and pack-objects error stream for progress bar.
79          */
80         int lp_pipe[2], pu_pipe[2], pe_pipe[2];
81         pid_t pid_rev_list, pid_pack_objects;
82         int create_full_pack = (nr_our_refs == nr_needs && !nr_has);
83         char data[8193], progress[128];
84         char abort_msg[] = "aborting due to possible repository "
85                 "corruption on the remote side.";
86         int buffered = -1;
87
88         if (pipe(lp_pipe) < 0)
89                 die("git-upload-pack: unable to create pipe");
90         pid_rev_list = fork();
91         if (pid_rev_list < 0)
92                 die("git-upload-pack: unable to fork git-rev-list");
93
94         if (!pid_rev_list) {
95                 int i;
96                 int args;
97                 const char **argv;
98                 char *buf;
99                 char **p;
100
101                 if (create_full_pack) {
102                         args = 10;
103                         use_thin_pack = 0; /* no point doing it */
104                 }
105                 else
106                         args = nr_has + nr_needs + 5;
107                 p = xmalloc(args * sizeof(char *));
108                 argv = (const char **) p;
109                 buf = xmalloc(args * 45);
110
111                 dup2(lp_pipe[1], 1);
112                 close(0);
113                 close(lp_pipe[0]);
114                 close(lp_pipe[1]);
115                 *p++ = "rev-list";
116                 *p++ = use_thin_pack ? "--objects-edge" : "--objects";
117                 if (create_full_pack || MAX_NEEDS <= nr_needs)
118                         *p++ = "--all";
119                 else {
120                         for (i = 0; i < nr_needs; i++) {
121                                 *p++ = buf;
122                                 memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
123                                 buf += 41;
124                         }
125                 }
126                 if (!create_full_pack)
127                         for (i = 0; i < nr_has; i++) {
128                                 *p++ = buf;
129                                 *buf++ = '^';
130                                 memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
131                                 buf += 41;
132                         }
133                 *p++ = NULL;
134                 execv_git_cmd(argv);
135                 die("git-upload-pack: unable to exec git-rev-list");
136         }
137
138         if (pipe(pu_pipe) < 0)
139                 die("git-upload-pack: unable to create pipe");
140         if (pipe(pe_pipe) < 0)
141                 die("git-upload-pack: unable to create pipe");
142         pid_pack_objects = fork();
143         if (pid_pack_objects < 0) {
144                 /* daemon sets things up to ignore TERM */
145                 kill(pid_rev_list, SIGKILL);
146                 die("git-upload-pack: unable to fork git-pack-objects");
147         }
148         if (!pid_pack_objects) {
149                 dup2(lp_pipe[0], 0);
150                 dup2(pu_pipe[1], 1);
151                 dup2(pe_pipe[1], 2);
152
153                 close(lp_pipe[0]);
154                 close(lp_pipe[1]);
155                 close(pu_pipe[0]);
156                 close(pu_pipe[1]);
157                 close(pe_pipe[0]);
158                 close(pe_pipe[1]);
159                 execl_git_cmd("pack-objects", "--stdout", "--progress", NULL);
160                 kill(pid_rev_list, SIGKILL);
161                 die("git-upload-pack: unable to exec git-pack-objects");
162         }
163
164         close(lp_pipe[0]);
165         close(lp_pipe[1]);
166
167         /* We read from pe_pipe[0] to capture stderr output for
168          * progress bar, and pu_pipe[0] to capture the pack data.
169          */
170         close(pe_pipe[1]);
171         close(pu_pipe[1]);
172
173         while (1) {
174                 const char *who;
175                 struct pollfd pfd[2];
176                 pid_t pid;
177                 int status;
178                 ssize_t sz;
179                 int pe, pu, pollsize;
180
181                 pollsize = 0;
182                 pe = pu = -1;
183
184                 if (0 <= pu_pipe[0]) {
185                         pfd[pollsize].fd = pu_pipe[0];
186                         pfd[pollsize].events = POLLIN;
187                         pu = pollsize;
188                         pollsize++;
189                 }
190                 if (0 <= pe_pipe[0]) {
191                         pfd[pollsize].fd = pe_pipe[0];
192                         pfd[pollsize].events = POLLIN;
193                         pe = pollsize;
194                         pollsize++;
195                 }
196
197                 if (pollsize) {
198                         if (poll(pfd, pollsize, -1) < 0) {
199                                 if (errno != EINTR) {
200                                         error("poll failed, resuming: %s",
201                                               strerror(errno));
202                                         sleep(1);
203                                 }
204                                 continue;
205                         }
206                         if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
207                                 /* Data ready; we keep the last byte
208                                  * to ourselves in case we detect
209                                  * broken rev-list, so that we can
210                                  * leave the stream corrupted.  This
211                                  * is unfortunate -- unpack-objects
212                                  * would happily accept a valid pack
213                                  * data with trailing garbage, so
214                                  * appending garbage after we pass all
215                                  * the pack data is not good enough to
216                                  * signal breakage to downstream.
217                                  */
218                                 char *cp = data;
219                                 ssize_t outsz = 0;
220                                 if (0 <= buffered) {
221                                         *cp++ = buffered;
222                                         outsz++;
223                                 }
224                                 sz = read(pu_pipe[0], cp,
225                                           sizeof(data) - outsz);
226                                 if (0 < sz)
227                                                 ;
228                                 else if (sz == 0) {
229                                         close(pu_pipe[0]);
230                                         pu_pipe[0] = -1;
231                                 }
232                                 else
233                                         goto fail;
234                                 sz += outsz;
235                                 if (1 < sz) {
236                                         buffered = data[sz-1] & 0xFF;
237                                         sz--;
238                                 }
239                                 else
240                                         buffered = -1;
241                                 sz = send_client_data(1, data, sz);
242                                 if (sz < 0)
243                                         goto fail;
244                         }
245                         if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
246                                 /* Status ready; we ship that in the side-band
247                                  * or dump to the standard error.
248                                  */
249                                 sz = read(pe_pipe[0], progress,
250                                           sizeof(progress));
251                                 if (0 < sz)
252                                         send_client_data(2, progress, sz);
253                                 else if (sz == 0) {
254                                         close(pe_pipe[0]);
255                                         pe_pipe[0] = -1;
256                                 }
257                                 else
258                                         goto fail;
259                         }
260                 }
261
262                 /* See if the children are still there */
263                 if (pid_rev_list || pid_pack_objects) {
264                         pid = waitpid(-1, &status, WNOHANG);
265                         if (!pid)
266                                 continue;
267                         who = ((pid == pid_rev_list) ? "git-rev-list" :
268                                (pid == pid_pack_objects) ? "git-pack-objects" :
269                                NULL);
270                         if (!who) {
271                                 if (pid < 0) {
272                                         error("git-upload-pack: %s",
273                                               strerror(errno));
274                                         goto fail;
275                                 }
276                                 error("git-upload-pack: we weren't "
277                                       "waiting for %d", pid);
278                                 continue;
279                         }
280                         if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
281                                 error("git-upload-pack: %s died with error.",
282                                       who);
283                                 goto fail;
284                         }
285                         if (pid == pid_rev_list)
286                                 pid_rev_list = 0;
287                         if (pid == pid_pack_objects)
288                                 pid_pack_objects = 0;
289                         if (pid_rev_list || pid_pack_objects)
290                                 continue;
291                 }
292
293                 /* both died happily */
294                 if (pollsize)
295                         continue;
296
297                 /* flush the data */
298                 if (0 <= buffered) {
299                         data[0] = buffered;
300                         sz = send_client_data(1, data, 1);
301                         if (sz < 0)
302                                 goto fail;
303                         fprintf(stderr, "flushed.\n");
304                 }
305                 send_client_data(1, NULL, 0);
306                 return;
307         }
308  fail:
309         if (pid_pack_objects)
310                 kill(pid_pack_objects, SIGKILL);
311         if (pid_rev_list)
312                 kill(pid_rev_list, SIGKILL);
313         send_client_data(3, abort_msg, sizeof(abort_msg));
314         die("git-upload-pack: %s", abort_msg);
315 }
316
317 static int got_sha1(char *hex, unsigned char *sha1)
318 {
319         if (get_sha1_hex(hex, sha1))
320                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
321         if (!has_sha1_file(sha1))
322                 return 0;
323         if (nr_has < MAX_HAS) {
324                 struct object *o = lookup_object(sha1);
325                 if (!(o && o->parsed))
326                         o = parse_object(sha1);
327                 if (!o)
328                         die("oops (%s)", sha1_to_hex(sha1));
329                 if (o->type == TYPE_COMMIT) {
330                         struct commit_list *parents;
331                         if (o->flags & THEY_HAVE)
332                                 return 0;
333                         o->flags |= THEY_HAVE;
334                         for (parents = ((struct commit*)o)->parents;
335                              parents;
336                              parents = parents->next)
337                                 parents->item->object.flags |= THEY_HAVE;
338                 }
339                 memcpy(has_sha1[nr_has++], sha1, 20);
340         }
341         return 1;
342 }
343
344 static int get_common_commits(void)
345 {
346         static char line[1000];
347         unsigned char sha1[20], last_sha1[20];
348         int len;
349
350         track_object_refs = 0;
351         save_commit_buffer = 0;
352
353         for(;;) {
354                 len = packet_read_line(0, line, sizeof(line));
355                 reset_timeout();
356
357                 if (!len) {
358                         if (nr_has == 0 || multi_ack)
359                                 packet_write(1, "NAK\n");
360                         continue;
361                 }
362                 len = strip(line, len);
363                 if (!strncmp(line, "have ", 5)) {
364                         if (got_sha1(line+5, sha1) &&
365                                         (multi_ack || nr_has == 1)) {
366                                 if (nr_has >= MAX_HAS)
367                                         multi_ack = 0;
368                                 packet_write(1, "ACK %s%s\n",
369                                         sha1_to_hex(sha1),
370                                         multi_ack ?  " continue" : "");
371                                 if (multi_ack)
372                                         memcpy(last_sha1, sha1, 20);
373                         }
374                         continue;
375                 }
376                 if (!strcmp(line, "done")) {
377                         if (nr_has > 0) {
378                                 if (multi_ack)
379                                         packet_write(1, "ACK %s\n",
380                                                         sha1_to_hex(last_sha1));
381                                 return 0;
382                         }
383                         packet_write(1, "NAK\n");
384                         return -1;
385                 }
386                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
387         }
388 }
389
390 static int receive_needs(void)
391 {
392         static char line[1000];
393         int len, needs;
394
395         needs = 0;
396         for (;;) {
397                 struct object *o;
398                 unsigned char dummy[20], *sha1_buf;
399                 len = packet_read_line(0, line, sizeof(line));
400                 reset_timeout();
401                 if (!len)
402                         return needs;
403
404                 sha1_buf = dummy;
405                 if (needs == MAX_NEEDS) {
406                         fprintf(stderr,
407                                 "warning: supporting only a max of %d requests. "
408                                 "sending everything instead.\n",
409                                 MAX_NEEDS);
410                 }
411                 else if (needs < MAX_NEEDS)
412                         sha1_buf = needs_sha1[needs];
413
414                 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
415                         die("git-upload-pack: protocol error, "
416                             "expected to get sha, not '%s'", line);
417                 if (strstr(line+45, "multi_ack"))
418                         multi_ack = 1;
419                 if (strstr(line+45, "thin-pack"))
420                         use_thin_pack = 1;
421                 if (strstr(line+45, "side-band"))
422                         use_sideband = 1;
423
424                 /* We have sent all our refs already, and the other end
425                  * should have chosen out of them; otherwise they are
426                  * asking for nonsense.
427                  *
428                  * Hmph.  We may later want to allow "want" line that
429                  * asks for something like "master~10" (symbolic)...
430                  * would it make sense?  I don't know.
431                  */
432                 o = lookup_object(sha1_buf);
433                 if (!o || !(o->flags & OUR_REF))
434                         die("git-upload-pack: not our ref %s", line+5);
435                 if (!(o->flags & WANTED)) {
436                         o->flags |= WANTED;
437                         needs++;
438                 }
439         }
440 }
441
442 static int send_ref(const char *refname, const unsigned char *sha1)
443 {
444         static char *capabilities = "multi_ack thin-pack side-band";
445         struct object *o = parse_object(sha1);
446
447         if (!o)
448                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
449
450         if (capabilities)
451                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
452                         0, capabilities);
453         else
454                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
455         capabilities = NULL;
456         if (!(o->flags & OUR_REF)) {
457                 o->flags |= OUR_REF;
458                 nr_our_refs++;
459         }
460         if (o->type == TYPE_TAG) {
461                 o = deref_tag(o, refname, 0);
462                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
463         }
464         return 0;
465 }
466
467 static int upload_pack(void)
468 {
469         reset_timeout();
470         head_ref(send_ref);
471         for_each_ref(send_ref);
472         packet_flush(1);
473         nr_needs = receive_needs();
474         if (!nr_needs)
475                 return 0;
476         get_common_commits();
477         create_pack_file();
478         return 0;
479 }
480
481 int main(int argc, char **argv)
482 {
483         char *dir;
484         int i;
485         int strict = 0;
486
487         for (i = 1; i < argc; i++) {
488                 char *arg = argv[i];
489
490                 if (arg[0] != '-')
491                         break;
492                 if (!strcmp(arg, "--strict")) {
493                         strict = 1;
494                         continue;
495                 }
496                 if (!strncmp(arg, "--timeout=", 10)) {
497                         timeout = atoi(arg+10);
498                         continue;
499                 }
500                 if (!strcmp(arg, "--")) {
501                         i++;
502                         break;
503                 }
504         }
505         
506         if (i != argc-1)
507                 usage(upload_pack_usage);
508         dir = argv[i];
509
510         if (!enter_repo(dir, strict))
511                 die("'%s': unable to chdir or not a git archive", dir);
512
513         upload_pack();
514         return 0;
515 }