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