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] [--force] [--receive-pack=<git-receive-pack>] [--verbose] [--thin] [<host>:]<directory> [<ref>...]\n"
  10 "  --all and explicit <ref> specification are mutually exclusive.";
  11 static const char *receivepack = "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 < 0)
  29                 return error("send-pack: unable to fork git-pack-objects");
  30         if (!pid) {
  31                 /*
  32                  * The child becomes pack-objects --revs; we feed
  33                  * the revision parameters to it via its stdin and
  34                  * let its stdout go back to the other end.
  35                  */
  36                 static const char *args[] = {
  37                         "pack-objects",
  38                         "--all-progress",
  39                         "--revs",
  40                         "--stdout",
  41                         NULL,
  42                         NULL,
  43                 };
  44                 if (use_thin_pack)
  45                         args[4] = "--thin";
  46                 dup2(pipe_fd[0], 0);
  47                 dup2(fd, 1);
  48                 close(pipe_fd[0]);
  49                 close(pipe_fd[1]);
  50                 close(fd);
  51                 execv_git_cmd(args);
  52                 die("git-pack-objects exec failed (%s)", strerror(errno));
  53         }
  54
  55         /*
  56          * We feed the pack-objects we just spawned with revision
  57          * parameters by writing to the pipe.
  58          */
  59         close(pipe_fd[0]);
  60         close(fd);
  61
  62         while (refs) {
  63                 char buf[42];
  64
  65                 if (!is_null_sha1(refs->old_sha1) &&
  66                     has_sha1_file(refs->old_sha1)) {
  67                         memcpy(buf + 1, sha1_to_hex(refs->old_sha1), 40);
  68                         buf[0] = '^';
  69                         buf[41] = '\n';
  70                         if (!write_or_whine(pipe_fd[1], buf, 42,
  71                                                 "send-pack: send refs"))
  72                                 break;
  73                 }
  74                 if (!is_null_sha1(refs->new_sha1)) {
  75                         memcpy(buf, sha1_to_hex(refs->new_sha1), 40);
  76                         buf[40] = '\n';
  77                         if (!write_or_whine(pipe_fd[1], buf, 41,
  78                                                 "send-pack: send refs"))
  79                                 break;
  80                 }
  81                 refs = refs->next;
  82         }
  83         close(pipe_fd[1]);
  84
  85         for (;;) {
  86                 int status, code;
  87                 pid_t waiting = waitpid(pid, &status, 0);
  88
  89                 if (waiting < 0) {
  90                         if (errno == EINTR)
  91                                 continue;
  92                         return error("waitpid failed (%s)", strerror(errno));
  93                 }
  94                 if ((waiting != pid) || WIFSIGNALED(status) ||
  95                     !WIFEXITED(status))
  96                         return error("pack-objects died with strange error");
  97                 code = WEXITSTATUS(status);
  98                 if (code)
  99                         return -code;
 100                 return 0;
 101         }
 102 }
 103
 104 static void unmark_and_free(struct commit_list *list, unsigned int mark)
 105 {
 106         while (list) {
 107                 struct commit_list *temp = list;
 108                 temp->item->object.flags &= ~mark;
 109                 list = temp->next;
 110                 free(temp);
 111         }
 112 }
 113
 114 static int ref_newer(const unsigned char *new_sha1,
 115                      const unsigned char *old_sha1)
 116 {
 117         struct object *o;
 118         struct commit *old, *new;
 119         struct commit_list *list, *used;
 120         int found = 0;
 121
 122         /* Both new and old must be commit-ish and new is descendant of
 123          * old.  Otherwise we require --force.
 124          */
 125         o = deref_tag(parse_object(old_sha1), NULL, 0);
 126         if (!o || o->type != OBJ_COMMIT)
 127                 return 0;
 128         old = (struct commit *) o;
 129
 130         o = deref_tag(parse_object(new_sha1), NULL, 0);
 131         if (!o || o->type != OBJ_COMMIT)
 132                 return 0;
 133         new = (struct commit *) o;
 134
 135         if (parse_commit(new) < 0)
 136                 return 0;
 137
 138         used = list = NULL;
 139         commit_list_insert(new, &list);
 140         while (list) {
 141                 new = pop_most_recent_commit(&list, 1);
 142                 commit_list_insert(new, &used);
 143                 if (new == old) {
 144                         found = 1;
 145                         break;
 146                 }
 147         }
 148         unmark_and_free(list, 1);
 149         unmark_and_free(used, 1);
 150         return found;
 151 }
 152
 153 static struct ref *local_refs, **local_tail;
 154 static struct ref *remote_refs, **remote_tail;
 155
 156 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 157 {
 158         struct ref *ref;
 159         int len = strlen(refname) + 1;
 160         ref = xcalloc(1, sizeof(*ref) + len);
 161         hashcpy(ref->new_sha1, sha1);
 162         memcpy(ref->name, refname, len);
 163         *local_tail = ref;
 164         local_tail = &ref->next;
 165         return 0;
 166 }
 167
 168 static void get_local_heads(void)
 169 {
 170         local_tail = &local_refs;
 171         for_each_ref(one_local_ref, NULL);
 172 }
 173
 174 static int receive_status(int in)
 175 {
 176         char line[1000];
 177         int ret = 0;
 178         int len = packet_read_line(in, line, sizeof(line));
 179         if (len < 10 || memcmp(line, "unpack ", 7)) {
 180                 fprintf(stderr, "did not receive status back\n");
 181                 return -1;
 182         }
 183         if (memcmp(line, "unpack ok\n", 10)) {
 184                 fputs(line, stderr);
 185                 ret = -1;
 186         }
 187         while (1) {
 188                 len = packet_read_line(in, line, sizeof(line));
 189                 if (!len)
 190                         break;
 191                 if (len < 3 ||
 192                     (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
 193                         fprintf(stderr, "protocol error: %s\n", line);
 194                         ret = -1;
 195                         break;
 196                 }
 197                 if (!memcmp(line, "ok", 2))
 198                         continue;
 199                 fputs(line, stderr);
 200                 ret = -1;
 201         }
 202         return ret;
 203 }
 204
 205 static int send_pack(int in, int out, int nr_refspec, char **refspec)
 206 {
 207         struct ref *ref;
 208         int new_refs;
 209         int ret = 0;
 210         int ask_for_status_report = 0;
 211         int allow_deleting_refs = 0;
 212         int expect_status_report = 0;
 213
 214         /* No funny business with the matcher */
 215         remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, REF_NORMAL);
 216         get_local_heads();
 217
 218         /* Does the other end support the reporting? */
 219         if (server_supports("report-status"))
 220                 ask_for_status_report = 1;
 221         if (server_supports("delete-refs"))
 222                 allow_deleting_refs = 1;
 223
 224         /* match them up */
 225         if (!remote_tail)
 226                 remote_tail = &remote_refs;
 227         if (match_refs(local_refs, remote_refs, &remote_tail,
 228                        nr_refspec, refspec, send_all))
 229                 return -1;
 230
 231         if (!remote_refs) {
 232                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
 233                 return 0;
 234         }
 235
 236         /*
 237          * Finally, tell the other end!
 238          */
 239         new_refs = 0;
 240         for (ref = remote_refs; ref; ref = ref->next) {
 241                 char old_hex[60], *new_hex;
 242                 int delete_ref;
 243
 244                 if (!ref->peer_ref)
 245                         continue;
 246
 247                 delete_ref = is_null_sha1(ref->peer_ref->new_sha1);
 248                 if (delete_ref && !allow_deleting_refs) {
 249                         error("remote does not support deleting refs");
 250                         ret = -2;
 251                         continue;
 252                 }
 253                 if (!delete_ref &&
 254                     !hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
 255                         if (verbose)
 256                                 fprintf(stderr, "'%s': up-to-date\n", ref->name);
 257                         continue;
 258                 }
 259
 260                 /* This part determines what can overwrite what.
 261                  * The rules are:
 262                  *
 263                  * (0) you can always use --force or +A:B notation to
 264                  *     selectively force individual ref pairs.
 265                  *
 266                  * (1) if the old thing does not exist, it is OK.
 267                  *
 268                  * (2) if you do not have the old thing, you are not allowed
 269                  *     to overwrite it; you would not know what you are losing
 270                  *     otherwise.
 271                  *
 272                  * (3) if both new and old are commit-ish, and new is a
 273                  *     descendant of old, it is OK.
 274                  *
 275                  * (4) regardless of all of the above, removing :B is
 276                  *     always allowed.
 277                  */
 278
 279                 if (!force_update &&
 280                     !delete_ref &&
 281                     !is_null_sha1(ref->old_sha1) &&
 282                     !ref->force) {
 283                         if (!has_sha1_file(ref->old_sha1) ||
 284                             !ref_newer(ref->peer_ref->new_sha1,
 285                                        ref->old_sha1)) {
 286                                 /* We do not have the remote ref, or
 287                                  * we know that the remote ref is not
 288                                  * an ancestor of what we are trying to
 289                                  * push.  Either way this can be losing
 290                                  * commits at the remote end and likely
 291                                  * we were not up to date to begin with.
 292                                  */
 293                                 error("remote '%s' is not a strict "
 294                                       "subset of local ref '%s'. "
 295                                       "maybe you are not up-to-date and "
 296                                       "need to pull first?",
 297                                       ref->name,
 298                                       ref->peer_ref->name);
 299                                 ret = -2;
 300                                 continue;
 301                         }
 302                 }
 303                 hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
 304                 if (!delete_ref)
 305                         new_refs++;
 306                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 307                 new_hex = sha1_to_hex(ref->new_sha1);
 308
 309                 if (ask_for_status_report) {
 310                         packet_write(out, "%s %s %s%c%s",
 311                                      old_hex, new_hex, ref->name, 0,
 312                                      "report-status");
 313                         ask_for_status_report = 0;
 314                         expect_status_report = 1;
 315                 }
 316                 else
 317                         packet_write(out, "%s %s %s",
 318                                      old_hex, new_hex, ref->name);
 319                 if (delete_ref)
 320                         fprintf(stderr, "deleting '%s'\n", ref->name);
 321                 else {
 322                         fprintf(stderr, "updating '%s'", ref->name);
 323                         if (strcmp(ref->name, ref->peer_ref->name))
 324                                 fprintf(stderr, " using '%s'",
 325                                         ref->peer_ref->name);
 326                         fprintf(stderr, "\n  from %s\n  to   %s\n",
 327                                 old_hex, new_hex);
 328                 }
 329         }
 330
 331         packet_flush(out);
 332         if (new_refs)
 333                 ret = pack_objects(out, remote_refs);
 334         close(out);
 335
 336         if (expect_status_report) {
 337                 if (receive_status(in))
 338                         ret = -4;
 339         }
 340
 341         if (!new_refs && ret == 0)
 342                 fprintf(stderr, "Everything up-to-date\n");
 343         return ret;
 344 }
 345
 346 static void verify_remote_names(int nr_heads, char **heads)
 347 {
 348         int i;
 349
 350         for (i = 0; i < nr_heads; i++) {
 351                 const char *remote = strchr(heads[i], ':');
 352
 353                 remote = remote ? (remote + 1) : heads[i];
 354                 switch (check_ref_format(remote)) {
 355                 case 0: /* ok */
 356                 case -2: /* ok but a single level -- that is fine for
 357                           * a match pattern.
 358                           */
 359                         continue;
 360                 }
 361                 die("remote part of refspec is not a valid name in %s",
 362                     heads[i]);
 363         }
 364 }
 365
 366 int main(int argc, char **argv)
 367 {
 368         int i, nr_heads = 0;
 369         char *dest = NULL;
 370         char **heads = NULL;
 371         int fd[2], ret;
 372         pid_t pid;
 373
 374         setup_git_directory();
 375         git_config(git_default_config);
 376
 377         argv++;
 378         for (i = 1; i < argc; i++, argv++) {
 379                 char *arg = *argv;
 380
 381                 if (*arg == '-') {
 382                         if (!prefixcmp(arg, "--receive-pack=")) {
 383                                 receivepack = arg + 15;
 384                                 continue;
 385                         }
 386                         if (!prefixcmp(arg, "--exec=")) {
 387                                 receivepack = arg + 7;
 388                                 continue;
 389                         }
 390                         if (!strcmp(arg, "--all")) {
 391                                 send_all = 1;
 392                                 continue;
 393                         }
 394                         if (!strcmp(arg, "--force")) {
 395                                 force_update = 1;
 396                                 continue;
 397                         }
 398                         if (!strcmp(arg, "--verbose")) {
 399                                 verbose = 1;
 400                                 continue;
 401                         }
 402                         if (!strcmp(arg, "--thin")) {
 403                                 use_thin_pack = 1;
 404                                 continue;
 405                         }
 406                         usage(send_pack_usage);
 407                 }
 408                 if (!dest) {
 409                         dest = arg;
 410                         continue;
 411                 }
 412                 heads = argv;
 413                 nr_heads = argc - i;
 414                 break;
 415         }
 416         if (!dest)
 417                 usage(send_pack_usage);
 418         if (heads && send_all)
 419                 usage(send_pack_usage);
 420         verify_remote_names(nr_heads, heads);
 421
 422         pid = git_connect(fd, dest, receivepack);
 423         if (pid < 0)
 424                 return 1;
 425         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 426         close(fd[0]);
 427         close(fd[1]);
 428         ret |= finish_connect(pid);
 429         return !!ret;
 430 }