send-pack.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "tag.h"
   4 #include "refs.h"
   5 #include "pkt-line.h"
   6 #include "exec_cmd.h"
   7
   8 static const char send_pack_usage[] =
   9 "git-send-pack [--all] [--exec=git-receive-pack] <remote> [<head>...]\n"
  10 "  --all and explicit <head> specification are mutually exclusive.";
  11 static const char *exec = "git-receive-pack";
  12 static int verbose;
  13 static int send_all;
  14 static int force_update;
  15 static int use_thin_pack;
  16
  17 /*
  18  * Make a pack stream and spit it out into file descriptor fd
  19  */
  20 static int pack_objects(int fd, struct ref *refs)
  21 {
  22         int pipe_fd[2];
  23         pid_t pid;
  24
  25         if (pipe(pipe_fd) < 0)
  26                 return error("send-pack: pipe failed");
  27         pid = fork();
  28         if (!pid) {
  29                 /*
  30                  * The child becomes pack-objects --revs; we feed
  31                  * the revision parameters to it via its stdin and
  32                  * let its stdout go back to the other end.
  33                  */
  34                 static const char *args[] = {
  35                         "pack-objects",
  36                         "--all-progress",
  37                         "--revs",
  38                         "--stdout",
  39                         NULL,
  40                         NULL,
  41                 };
  42                 if (use_thin_pack)
  43                         args[4] = "--thin";
  44                 dup2(pipe_fd[0], 0);
  45                 dup2(fd, 1);
  46                 close(pipe_fd[0]);
  47                 close(pipe_fd[1]);
  48                 close(fd);
  49                 execv_git_cmd(args);
  50                 die("git-pack-objects exec failed (%s)", strerror(errno));
  51         }
  52
  53         /*
  54          * We feed the pack-objects we just spawned with revision
  55          * parameters by writing to the pipe.
  56          */
  57         close(pipe_fd[0]);
  58         close(fd);
  59
  60         while (refs) {
  61                 char buf[42];
  62
  63                 if (!is_null_sha1(refs->old_sha1) &&
  64                     has_sha1_file(refs->old_sha1)) {
  65                         memcpy(buf + 1, sha1_to_hex(refs->old_sha1), 40);
  66                         buf[0] = '^';
  67                         buf[41] = '\n';
  68                         if (!write_or_whine(pipe_fd[1], buf, 42,
  69                                                 "send-pack: send refs"))
  70                                 break;
  71                 }
  72                 if (!is_null_sha1(refs->new_sha1)) {
  73                         memcpy(buf, sha1_to_hex(refs->new_sha1), 40);
  74                         buf[40] = '\n';
  75                         if (!write_or_whine(pipe_fd[1], buf, 41,
  76                                                 "send-pack: send refs"))
  77                                 break;
  78                 }
  79                 refs = refs->next;
  80         }
  81         close(pipe_fd[1]);
  82
  83         for (;;) {
  84                 int status, code;
  85                 pid_t waiting = waitpid(pid, &status, 0);
  86
  87                 if (waiting < 0) {
  88                         if (errno == EINTR)
  89                                 continue;
  90                         return error("waitpid failed (%s)", strerror(errno));
  91                 }
  92                 if ((waiting != pid) || WIFSIGNALED(status) ||
  93                     !WIFEXITED(status))
  94                         return error("pack-objects died with strange error");
  95                 code = WEXITSTATUS(status);
  96                 if (code)
  97                         return -code;
  98                 return 0;
  99         }
 100 }
 101
 102 static void unmark_and_free(struct commit_list *list, unsigned int mark)
 103 {
 104         while (list) {
 105                 struct commit_list *temp = list;
 106                 temp->item->object.flags &= ~mark;
 107                 list = temp->next;
 108                 free(temp);
 109         }
 110 }
 111
 112 static int ref_newer(const unsigned char *new_sha1,
 113                      const unsigned char *old_sha1)
 114 {
 115         struct object *o;
 116         struct commit *old, *new;
 117         struct commit_list *list, *used;
 118         int found = 0;
 119
 120         /* Both new and old must be commit-ish and new is descendant of
 121          * old.  Otherwise we require --force.
 122          */
 123         o = deref_tag(parse_object(old_sha1), NULL, 0);
 124         if (!o || o->type != OBJ_COMMIT)
 125                 return 0;
 126         old = (struct commit *) o;
 127
 128         o = deref_tag(parse_object(new_sha1), NULL, 0);
 129         if (!o || o->type != OBJ_COMMIT)
 130                 return 0;
 131         new = (struct commit *) o;
 132
 133         if (parse_commit(new) < 0)
 134                 return 0;
 135
 136         used = list = NULL;
 137         commit_list_insert(new, &list);
 138         while (list) {
 139                 new = pop_most_recent_commit(&list, 1);
 140                 commit_list_insert(new, &used);
 141                 if (new == old) {
 142                         found = 1;
 143                         break;
 144                 }
 145         }
 146         unmark_and_free(list, 1);
 147         unmark_and_free(used, 1);
 148         return found;
 149 }
 150
 151 static struct ref *local_refs, **local_tail;
 152 static struct ref *remote_refs, **remote_tail;
 153
 154 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 155 {
 156         struct ref *ref;
 157         int len = strlen(refname) + 1;
 158         ref = xcalloc(1, sizeof(*ref) + len);
 159         hashcpy(ref->new_sha1, sha1);
 160         memcpy(ref->name, refname, len);
 161         *local_tail = ref;
 162         local_tail = &ref->next;
 163         return 0;
 164 }
 165
 166 static void get_local_heads(void)
 167 {
 168         local_tail = &local_refs;
 169         for_each_ref(one_local_ref, NULL);
 170 }
 171
 172 static int receive_status(int in)
 173 {
 174         char line[1000];
 175         int ret = 0;
 176         int len = packet_read_line(in, line, sizeof(line));
 177         if (len < 10 || memcmp(line, "unpack ", 7)) {
 178                 fprintf(stderr, "did not receive status back\n");
 179                 return -1;
 180         }
 181         if (memcmp(line, "unpack ok\n", 10)) {
 182                 fputs(line, stderr);
 183                 ret = -1;
 184         }
 185         while (1) {
 186                 len = packet_read_line(in, line, sizeof(line));
 187                 if (!len)
 188                         break;
 189                 if (len < 3 ||
 190                     (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
 191                         fprintf(stderr, "protocol error: %s\n", line);
 192                         ret = -1;
 193                         break;
 194                 }
 195                 if (!memcmp(line, "ok", 2))
 196                         continue;
 197                 fputs(line, stderr);
 198                 ret = -1;
 199         }
 200         return ret;
 201 }
 202
 203 static int send_pack(int in, int out, int nr_refspec, char **refspec)
 204 {
 205         struct ref *ref;
 206         int new_refs;
 207         int ret = 0;
 208         int ask_for_status_report = 0;
 209         int allow_deleting_refs = 0;
 210         int expect_status_report = 0;
 211
 212         /* No funny business with the matcher */
 213         remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, REF_NORMAL);
 214         get_local_heads();
 215
 216         /* Does the other end support the reporting? */
 217         if (server_supports("report-status"))
 218                 ask_for_status_report = 1;
 219         if (server_supports("delete-refs"))
 220                 allow_deleting_refs = 1;
 221
 222         /* match them up */
 223         if (!remote_tail)
 224                 remote_tail = &remote_refs;
 225         if (match_refs(local_refs, remote_refs, &remote_tail,
 226                        nr_refspec, refspec, send_all))
 227                 return -1;
 228
 229         if (!remote_refs) {
 230                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
 231                 return 0;
 232         }
 233
 234         /*
 235          * Finally, tell the other end!
 236          */
 237         new_refs = 0;
 238         for (ref = remote_refs; ref; ref = ref->next) {
 239                 char old_hex[60], *new_hex;
 240                 int delete_ref;
 241
 242                 if (!ref->peer_ref)
 243                         continue;
 244
 245                 delete_ref = is_null_sha1(ref->peer_ref->new_sha1);
 246                 if (delete_ref && !allow_deleting_refs) {
 247                         error("remote does not support deleting refs");
 248                         ret = -2;
 249                         continue;
 250                 }
 251                 if (!delete_ref &&
 252                     !hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
 253                         if (verbose)
 254                                 fprintf(stderr, "'%s': up-to-date\n", ref->name);
 255                         continue;
 256                 }
 257
 258                 /* This part determines what can overwrite what.
 259                  * The rules are:
 260                  *
 261                  * (0) you can always use --force or +A:B notation to
 262                  *     selectively force individual ref pairs.
 263                  *
 264                  * (1) if the old thing does not exist, it is OK.
 265                  *
 266                  * (2) if you do not have the old thing, you are not allowed
 267                  *     to overwrite it; you would not know what you are losing
 268                  *     otherwise.
 269                  *
 270                  * (3) if both new and old are commit-ish, and new is a
 271                  *     descendant of old, it is OK.
 272                  *
 273                  * (4) regardless of all of the above, removing :B is
 274                  *     always allowed.
 275                  */
 276
 277                 if (!force_update &&
 278                     !delete_ref &&
 279                     !is_null_sha1(ref->old_sha1) &&
 280                     !ref->force) {
 281                         if (!has_sha1_file(ref->old_sha1) ||
 282                             !ref_newer(ref->peer_ref->new_sha1,
 283                                        ref->old_sha1)) {
 284                                 /* We do not have the remote ref, or
 285                                  * we know that the remote ref is not
 286                                  * an ancestor of what we are trying to
 287                                  * push.  Either way this can be losing
 288                                  * commits at the remote end and likely
 289                                  * we were not up to date to begin with.
 290                                  */
 291                                 error("remote '%s' is not a strict "
 292                                       "subset of local ref '%s'. "
 293                                       "maybe you are not up-to-date and "
 294                                       "need to pull first?",
 295                                       ref->name,
 296                                       ref->peer_ref->name);
 297                                 ret = -2;
 298                                 continue;
 299                         }
 300                 }
 301                 hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
 302                 if (!delete_ref)
 303                         new_refs++;
 304                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 305                 new_hex = sha1_to_hex(ref->new_sha1);
 306
 307                 if (ask_for_status_report) {
 308                         packet_write(out, "%s %s %s%c%s",
 309                                      old_hex, new_hex, ref->name, 0,
 310                                      "report-status");
 311                         ask_for_status_report = 0;
 312                         expect_status_report = 1;
 313                 }
 314                 else
 315                         packet_write(out, "%s %s %s",
 316                                      old_hex, new_hex, ref->name);
 317                 if (delete_ref)
 318                         fprintf(stderr, "deleting '%s'\n", ref->name);
 319                 else {
 320                         fprintf(stderr, "updating '%s'", ref->name);
 321                         if (strcmp(ref->name, ref->peer_ref->name))
 322                                 fprintf(stderr, " using '%s'",
 323                                         ref->peer_ref->name);
 324                         fprintf(stderr, "\n  from %s\n  to   %s\n",
 325                                 old_hex, new_hex);
 326                 }
 327         }
 328
 329         packet_flush(out);
 330         if (new_refs)
 331                 ret = pack_objects(out, remote_refs);
 332         close(out);
 333
 334         if (expect_status_report) {
 335                 if (receive_status(in))
 336                         ret = -4;
 337         }
 338
 339         if (!new_refs && ret == 0)
 340                 fprintf(stderr, "Everything up-to-date\n");
 341         return ret;
 342 }
 343
 344 static void verify_remote_names(int nr_heads, char **heads)
 345 {
 346         int i;
 347
 348         for (i = 0; i < nr_heads; i++) {
 349                 const char *remote = strchr(heads[i], ':');
 350
 351                 remote = remote ? (remote + 1) : heads[i];
 352                 switch (check_ref_format(remote)) {
 353                 case 0: /* ok */
 354                 case -2: /* ok but a single level -- that is fine for
 355                           * a match pattern.
 356                           */
 357                         continue;
 358                 }
 359                 die("remote part of refspec is not a valid name in %s",
 360                     heads[i]);
 361         }
 362 }
 363
 364 int main(int argc, char **argv)
 365 {
 366         int i, nr_heads = 0;
 367         char *dest = NULL;
 368         char **heads = NULL;
 369         int fd[2], ret;
 370         pid_t pid;
 371
 372         setup_git_directory();
 373         git_config(git_default_config);
 374
 375         argv++;
 376         for (i = 1; i < argc; i++, argv++) {
 377                 char *arg = *argv;
 378
 379                 if (*arg == '-') {
 380                         if (!strncmp(arg, "--exec=", 7)) {
 381                                 exec = arg + 7;
 382                                 continue;
 383                         }
 384                         if (!strcmp(arg, "--all")) {
 385                                 send_all = 1;
 386                                 continue;
 387                         }
 388                         if (!strcmp(arg, "--force")) {
 389                                 force_update = 1;
 390                                 continue;
 391                         }
 392                         if (!strcmp(arg, "--verbose")) {
 393                                 verbose = 1;
 394                                 continue;
 395                         }
 396                         if (!strcmp(arg, "--thin")) {
 397                                 use_thin_pack = 1;
 398                                 continue;
 399                         }
 400                         usage(send_pack_usage);
 401                 }
 402                 if (!dest) {
 403                         dest = arg;
 404                         continue;
 405                 }
 406                 heads = argv;
 407                 nr_heads = argc - i;
 408                 break;
 409         }
 410         if (!dest)
 411                 usage(send_pack_usage);
 412         if (heads && send_all)
 413                 usage(send_pack_usage);
 414         verify_remote_names(nr_heads, heads);
 415
 416         pid = git_connect(fd, dest, exec);
 417         if (pid < 0)
 418                 return 1;
 419         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 420         close(fd[0]);
 421         close(fd[1]);
 422         ret |= finish_connect(pid);
 423         return !!ret;
 424 }