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 static void exec_pack_objects(void)
  18 {
  19         static const char *args[] = {
  20                 "pack-objects",
  21                 "--all-progress",
  22                 "--stdout",
  23                 NULL
  24         };
  25         execv_git_cmd(args);
  26         die("git-pack-objects exec failed (%s)", strerror(errno));
  27 }
  28
  29 static void exec_rev_list(struct ref *refs)
  30 {
  31         static const char *args[4];
  32         int i = 0;
  33
  34         args[i++] = "rev-list"; /* 0 */
  35         if (use_thin_pack)      /* 1 */
  36                 args[i++] = "--objects-edge";
  37         else
  38                 args[i++] = "--objects";
  39
  40         args[i++] = "--stdin";
  41
  42         args[i] = NULL;
  43         execv_git_cmd(args);
  44         die("git-rev-list exec failed (%s)", strerror(errno));
  45 }
  46
  47 /*
  48  * Run "rev-list --stdin | pack-objects" pipe.
  49  */
  50 static void rev_list(struct ref *refs)
  51 {
  52         int pipe_fd[2];
  53         pid_t pack_objects_pid;
  54
  55         if (pipe(pipe_fd) < 0)
  56                 die("rev-list setup: pipe failed");
  57         pack_objects_pid = fork();
  58         if (!pack_objects_pid) {
  59                 /* The child becomes pack-objects; reads from pipe
  60                  * and writes to the original fd
  61                  */
  62                 dup2(pipe_fd[0], 0);
  63                 close(pipe_fd[0]);
  64                 close(pipe_fd[1]);
  65                 exec_pack_objects();
  66                 die("pack-objects setup failed");
  67         }
  68         if (pack_objects_pid < 0)
  69                 die("pack-objects fork failed");
  70
  71         /* We become rev-list --stdin; output goes to pipe. */
  72         dup2(pipe_fd[1], 1);
  73         close(pipe_fd[0]);
  74         close(pipe_fd[1]);
  75         exec_rev_list(refs);
  76 }
  77
  78 /*
  79  * Create "rev-list --stdin | pack-objects" pipe and feed
  80  * the refs into the pipeline.
  81  */
  82 static void rev_list_generate(int fd, struct ref *refs)
  83 {
  84         int pipe_fd[2];
  85         pid_t rev_list_generate_pid;
  86
  87         if (pipe(pipe_fd) < 0)
  88                 die("rev-list-generate setup: pipe failed");
  89         rev_list_generate_pid = fork();
  90         if (!rev_list_generate_pid) {
  91                 /* The child becomes the "rev-list | pack-objects"
  92                  * pipeline.  It takes input from us, and its output
  93                  * goes to fd.
  94                  */
  95                 dup2(pipe_fd[0], 0);
  96                 dup2(fd, 1);
  97                 close(pipe_fd[0]);
  98                 close(pipe_fd[1]);
  99                 close(fd);
 100                 rev_list(refs);
 101                 die("rev-list setup failed");
 102         }
 103         if (rev_list_generate_pid < 0)
 104                 die("rev-list-generate fork failed");
 105
 106         /* We feed the rev parameters to them.  We do not write into
 107          * fd nor read from the pipe.
 108          */
 109         close(pipe_fd[0]);
 110         close(fd);
 111         while (refs) {
 112                 char buf[42];
 113
 114                 if (!is_null_sha1(refs->old_sha1) &&
 115                     has_sha1_file(refs->old_sha1)) {
 116                         memcpy(buf + 1, sha1_to_hex(refs->old_sha1), 40);
 117                         buf[0] = '^';
 118                         buf[41] = '\n';
 119                         write(pipe_fd[1], buf, 42);
 120                 }
 121                 if (!is_null_sha1(refs->new_sha1)) {
 122                         memcpy(buf, sha1_to_hex(refs->new_sha1), 40);
 123                         buf[40] = '\n';
 124                         write(pipe_fd[1], buf, 41);
 125                 }
 126                 refs = refs->next;
 127         }
 128         close(pipe_fd[1]);
 129         // waitpid(rev_list_generate_pid);
 130         exit(0);
 131 }
 132
 133 /*
 134  * Make a pack stream and spit it out into file descriptor fd
 135  */
 136 static void pack_objects(int fd, struct ref *refs)
 137 {
 138         pid_t rev_list_pid;
 139
 140         rev_list_pid = fork();
 141         if (!rev_list_pid) {
 142                 rev_list_generate(fd, refs);
 143                 die("rev-list setup failed");
 144         }
 145         if (rev_list_pid < 0)
 146                 die("rev-list fork failed");
 147         /*
 148          * We don't wait for the rev-list pipeline in the parent:
 149          * we end up waiting for the other end instead
 150          */
 151 }
 152
 153 static void unmark_and_free(struct commit_list *list, unsigned int mark)
 154 {
 155         while (list) {
 156                 struct commit_list *temp = list;
 157                 temp->item->object.flags &= ~mark;
 158                 list = temp->next;
 159                 free(temp);
 160         }
 161 }
 162
 163 static int ref_newer(const unsigned char *new_sha1,
 164                      const unsigned char *old_sha1)
 165 {
 166         struct object *o;
 167         struct commit *old, *new;
 168         struct commit_list *list, *used;
 169         int found = 0;
 170
 171         /* Both new and old must be commit-ish and new is descendant of
 172          * old.  Otherwise we require --force.
 173          */
 174         o = deref_tag(parse_object(old_sha1), NULL, 0);
 175         if (!o || o->type != OBJ_COMMIT)
 176                 return 0;
 177         old = (struct commit *) o;
 178
 179         o = deref_tag(parse_object(new_sha1), NULL, 0);
 180         if (!o || o->type != OBJ_COMMIT)
 181                 return 0;
 182         new = (struct commit *) o;
 183
 184         if (parse_commit(new) < 0)
 185                 return 0;
 186
 187         used = list = NULL;
 188         commit_list_insert(new, &list);
 189         while (list) {
 190                 new = pop_most_recent_commit(&list, 1);
 191                 commit_list_insert(new, &used);
 192                 if (new == old) {
 193                         found = 1;
 194                         break;
 195                 }
 196         }
 197         unmark_and_free(list, 1);
 198         unmark_and_free(used, 1);
 199         return found;
 200 }
 201
 202 static struct ref *local_refs, **local_tail;
 203 static struct ref *remote_refs, **remote_tail;
 204
 205 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 206 {
 207         struct ref *ref;
 208         int len = strlen(refname) + 1;
 209         ref = xcalloc(1, sizeof(*ref) + len);
 210         hashcpy(ref->new_sha1, sha1);
 211         memcpy(ref->name, refname, len);
 212         *local_tail = ref;
 213         local_tail = &ref->next;
 214         return 0;
 215 }
 216
 217 static void get_local_heads(void)
 218 {
 219         local_tail = &local_refs;
 220         for_each_ref(one_local_ref, NULL);
 221 }
 222
 223 static int receive_status(int in)
 224 {
 225         char line[1000];
 226         int ret = 0;
 227         int len = packet_read_line(in, line, sizeof(line));
 228         if (len < 10 || memcmp(line, "unpack ", 7)) {
 229                 fprintf(stderr, "did not receive status back\n");
 230                 return -1;
 231         }
 232         if (memcmp(line, "unpack ok\n", 10)) {
 233                 fputs(line, stderr);
 234                 ret = -1;
 235         }
 236         while (1) {
 237                 len = packet_read_line(in, line, sizeof(line));
 238                 if (!len)
 239                         break;
 240                 if (len < 3 ||
 241                     (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
 242                         fprintf(stderr, "protocol error: %s\n", line);
 243                         ret = -1;
 244                         break;
 245                 }
 246                 if (!memcmp(line, "ok", 2))
 247                         continue;
 248                 fputs(line, stderr);
 249                 ret = -1;
 250         }
 251         return ret;
 252 }
 253
 254 static int send_pack(int in, int out, int nr_refspec, char **refspec)
 255 {
 256         struct ref *ref;
 257         int new_refs;
 258         int ret = 0;
 259         int ask_for_status_report = 0;
 260         int allow_deleting_refs = 0;
 261         int expect_status_report = 0;
 262
 263         /* No funny business with the matcher */
 264         remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, REF_NORMAL);
 265         get_local_heads();
 266
 267         /* Does the other end support the reporting? */
 268         if (server_supports("report-status"))
 269                 ask_for_status_report = 1;
 270         if (server_supports("delete-refs"))
 271                 allow_deleting_refs = 1;
 272
 273         /* match them up */
 274         if (!remote_tail)
 275                 remote_tail = &remote_refs;
 276         if (match_refs(local_refs, remote_refs, &remote_tail,
 277                        nr_refspec, refspec, send_all))
 278                 return -1;
 279
 280         if (!remote_refs) {
 281                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
 282                 return 0;
 283         }
 284
 285         /*
 286          * Finally, tell the other end!
 287          */
 288         new_refs = 0;
 289         for (ref = remote_refs; ref; ref = ref->next) {
 290                 char old_hex[60], *new_hex;
 291                 int delete_ref;
 292
 293                 if (!ref->peer_ref)
 294                         continue;
 295
 296                 delete_ref = is_null_sha1(ref->peer_ref->new_sha1);
 297                 if (delete_ref && !allow_deleting_refs) {
 298                         error("remote does not support deleting refs");
 299                         ret = -2;
 300                         continue;
 301                 }
 302                 if (!delete_ref &&
 303                     !hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
 304                         if (verbose)
 305                                 fprintf(stderr, "'%s': up-to-date\n", ref->name);
 306                         continue;
 307                 }
 308
 309                 /* This part determines what can overwrite what.
 310                  * The rules are:
 311                  *
 312                  * (0) you can always use --force or +A:B notation to
 313                  *     selectively force individual ref pairs.
 314                  *
 315                  * (1) if the old thing does not exist, it is OK.
 316                  *
 317                  * (2) if you do not have the old thing, you are not allowed
 318                  *     to overwrite it; you would not know what you are losing
 319                  *     otherwise.
 320                  *
 321                  * (3) if both new and old are commit-ish, and new is a
 322                  *     descendant of old, it is OK.
 323                  *
 324                  * (4) regardless of all of the above, removing :B is
 325                  *     always allowed.
 326                  */
 327
 328                 if (!force_update &&
 329                     !delete_ref &&
 330                     !is_null_sha1(ref->old_sha1) &&
 331                     !ref->force) {
 332                         if (!has_sha1_file(ref->old_sha1) ||
 333                             !ref_newer(ref->peer_ref->new_sha1,
 334                                        ref->old_sha1)) {
 335                                 /* We do not have the remote ref, or
 336                                  * we know that the remote ref is not
 337                                  * an ancestor of what we are trying to
 338                                  * push.  Either way this can be losing
 339                                  * commits at the remote end and likely
 340                                  * we were not up to date to begin with.
 341                                  */
 342                                 error("remote '%s' is not a strict "
 343                                       "subset of local ref '%s'. "
 344                                       "maybe you are not up-to-date and "
 345                                       "need to pull first?",
 346                                       ref->name,
 347                                       ref->peer_ref->name);
 348                                 ret = -2;
 349                                 continue;
 350                         }
 351                 }
 352                 hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
 353                 if (!delete_ref)
 354                         new_refs++;
 355                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 356                 new_hex = sha1_to_hex(ref->new_sha1);
 357
 358                 if (ask_for_status_report) {
 359                         packet_write(out, "%s %s %s%c%s",
 360                                      old_hex, new_hex, ref->name, 0,
 361                                      "report-status");
 362                         ask_for_status_report = 0;
 363                         expect_status_report = 1;
 364                 }
 365                 else
 366                         packet_write(out, "%s %s %s",
 367                                      old_hex, new_hex, ref->name);
 368                 if (delete_ref)
 369                         fprintf(stderr, "deleting '%s'\n", ref->name);
 370                 else {
 371                         fprintf(stderr, "updating '%s'", ref->name);
 372                         if (strcmp(ref->name, ref->peer_ref->name))
 373                                 fprintf(stderr, " using '%s'",
 374                                         ref->peer_ref->name);
 375                         fprintf(stderr, "\n  from %s\n  to   %s\n",
 376                                 old_hex, new_hex);
 377                 }
 378         }
 379
 380         packet_flush(out);
 381         if (new_refs)
 382                 pack_objects(out, remote_refs);
 383         close(out);
 384
 385         if (expect_status_report) {
 386                 if (receive_status(in))
 387                         ret = -4;
 388         }
 389
 390         if (!new_refs && ret == 0)
 391                 fprintf(stderr, "Everything up-to-date\n");
 392         return ret;
 393 }
 394
 395 static void verify_remote_names(int nr_heads, char **heads)
 396 {
 397         int i;
 398
 399         for (i = 0; i < nr_heads; i++) {
 400                 const char *remote = strchr(heads[i], ':');
 401
 402                 remote = remote ? (remote + 1) : heads[i];
 403                 switch (check_ref_format(remote)) {
 404                 case 0: /* ok */
 405                 case -2: /* ok but a single level -- that is fine for
 406                           * a match pattern.
 407                           */
 408                         continue;
 409                 }
 410                 die("remote part of refspec is not a valid name in %s",
 411                     heads[i]);
 412         }
 413 }
 414
 415 int main(int argc, char **argv)
 416 {
 417         int i, nr_heads = 0;
 418         char *dest = NULL;
 419         char **heads = NULL;
 420         int fd[2], ret;
 421         pid_t pid;
 422
 423         setup_git_directory();
 424         git_config(git_default_config);
 425
 426         argv++;
 427         for (i = 1; i < argc; i++, argv++) {
 428                 char *arg = *argv;
 429
 430                 if (*arg == '-') {
 431                         if (!strncmp(arg, "--exec=", 7)) {
 432                                 exec = arg + 7;
 433                                 continue;
 434                         }
 435                         if (!strcmp(arg, "--all")) {
 436                                 send_all = 1;
 437                                 continue;
 438                         }
 439                         if (!strcmp(arg, "--force")) {
 440                                 force_update = 1;
 441                                 continue;
 442                         }
 443                         if (!strcmp(arg, "--verbose")) {
 444                                 verbose = 1;
 445                                 continue;
 446                         }
 447                         if (!strcmp(arg, "--thin")) {
 448                                 use_thin_pack = 1;
 449                                 continue;
 450                         }
 451                         usage(send_pack_usage);
 452                 }
 453                 if (!dest) {
 454                         dest = arg;
 455                         continue;
 456                 }
 457                 heads = argv;
 458                 nr_heads = argc - i;
 459                 break;
 460         }
 461         if (!dest)
 462                 usage(send_pack_usage);
 463         if (heads && send_all)
 464                 usage(send_pack_usage);
 465         verify_remote_names(nr_heads, heads);
 466
 467         pid = git_connect(fd, dest, exec);
 468         if (pid < 0)
 469                 return 1;
 470         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 471         close(fd[0]);
 472         close(fd[1]);
 473         ret |= finish_connect(pid);
 474         return !!ret;
 475 }