Merge branch 'jc/apply'
[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, nr_our_refs;
18 static int use_thin_pack;
19 static struct object_array have_obj;
20 static struct object_array want_obj;
21 static unsigned int timeout;
22 static int use_sideband;
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], last_sha1[20];
355         int len;
356
357         track_object_refs = 0;
358         save_commit_buffer = 0;
359
360         for(;;) {
361                 len = packet_read_line(0, line, sizeof(line));
362                 reset_timeout();
363
364                 if (!len) {
365                         if (have_obj.nr == 0 || multi_ack)
366                                 packet_write(1, "NAK\n");
367                         continue;
368                 }
369                 len = strip(line, len);
370                 if (!strncmp(line, "have ", 5)) {
371                         if (got_sha1(line+5, sha1) &&
372                             (multi_ack || have_obj.nr == 1)) {
373                                 packet_write(1, "ACK %s%s\n",
374                                              sha1_to_hex(sha1),
375                                              multi_ack ?  " continue" : "");
376                                 if (multi_ack)
377                                         hashcpy(last_sha1, sha1);
378                         }
379                         continue;
380                 }
381                 if (!strcmp(line, "done")) {
382                         if (have_obj.nr > 0) {
383                                 if (multi_ack)
384                                         packet_write(1, "ACK %s\n",
385                                                         sha1_to_hex(last_sha1));
386                                 return 0;
387                         }
388                         packet_write(1, "NAK\n");
389                         return -1;
390                 }
391                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
392         }
393 }
394
395 static void receive_needs(void)
396 {
397         static char line[1000];
398         int len;
399
400         for (;;) {
401                 struct object *o;
402                 unsigned char sha1_buf[20];
403                 len = packet_read_line(0, line, sizeof(line));
404                 reset_timeout();
405                 if (!len)
406                         return;
407
408                 if (strncmp("want ", line, 5) ||
409                     get_sha1_hex(line+5, sha1_buf))
410                         die("git-upload-pack: protocol error, "
411                             "expected to get sha, not '%s'", line);
412                 if (strstr(line+45, "multi_ack"))
413                         multi_ack = 1;
414                 if (strstr(line+45, "thin-pack"))
415                         use_thin_pack = 1;
416                 if (strstr(line+45, "side-band"))
417                         use_sideband = 1;
418
419                 /* We have sent all our refs already, and the other end
420                  * should have chosen out of them; otherwise they are
421                  * asking for nonsense.
422                  *
423                  * Hmph.  We may later want to allow "want" line that
424                  * asks for something like "master~10" (symbolic)...
425                  * would it make sense?  I don't know.
426                  */
427                 o = lookup_object(sha1_buf);
428                 if (!o || !(o->flags & OUR_REF))
429                         die("git-upload-pack: not our ref %s", line+5);
430                 if (!(o->flags & WANTED)) {
431                         o->flags |= WANTED;
432                         add_object_array(o, NULL, &want_obj);
433                 }
434         }
435 }
436
437 static int send_ref(const char *refname, const unsigned char *sha1)
438 {
439         static const char *capabilities = "multi_ack thin-pack side-band";
440         struct object *o = parse_object(sha1);
441
442         if (!o)
443                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
444
445         if (capabilities)
446                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
447                         0, capabilities);
448         else
449                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
450         capabilities = NULL;
451         if (!(o->flags & OUR_REF)) {
452                 o->flags |= OUR_REF;
453                 nr_our_refs++;
454         }
455         if (o->type == OBJ_TAG) {
456                 o = deref_tag(o, refname, 0);
457                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
458         }
459         return 0;
460 }
461
462 static void upload_pack(void)
463 {
464         reset_timeout();
465         head_ref(send_ref);
466         for_each_ref(send_ref);
467         packet_flush(1);
468         receive_needs();
469         if (want_obj.nr) {
470                 get_common_commits();
471                 create_pack_file();
472         }
473 }
474
475 int main(int argc, char **argv)
476 {
477         char *dir;
478         int i;
479         int strict = 0;
480
481         for (i = 1; i < argc; i++) {
482                 char *arg = argv[i];
483
484                 if (arg[0] != '-')
485                         break;
486                 if (!strcmp(arg, "--strict")) {
487                         strict = 1;
488                         continue;
489                 }
490                 if (!strncmp(arg, "--timeout=", 10)) {
491                         timeout = atoi(arg+10);
492                         continue;
493                 }
494                 if (!strcmp(arg, "--")) {
495                         i++;
496                         break;
497                 }
498         }
499         
500         if (i != argc-1)
501                 usage(upload_pack_usage);
502         dir = argv[i];
503
504         if (!enter_repo(dir, strict))
505                 die("'%s': unable to chdir or not a git archive", dir);
506
507         upload_pack();
508         return 0;
509 }