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