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 int is_zero_sha1(const unsigned char *sha1)
  18 {
  19         int i;
  20
  21         for (i = 0; i < 20; i++) {
  22                 if (*sha1++)
  23                         return 0;
  24         }
  25         return 1;
  26 }
  27
  28 static void exec_pack_objects(void)
  29 {
  30         static const char *args[] = {
  31                 "pack-objects",
  32                 "--all-progress",
  33                 "--stdout",
  34                 NULL
  35         };
  36         execv_git_cmd(args);
  37         die("git-pack-objects exec failed (%s)", strerror(errno));
  38 }
  39
  40 static void exec_rev_list(struct ref *refs)
  41 {
  42         static const char *args[4];
  43         int i = 0;
  44
  45         args[i++] = "rev-list"; /* 0 */
  46         if (use_thin_pack)      /* 1 */
  47                 args[i++] = "--objects-edge";
  48         else
  49                 args[i++] = "--objects";
  50
  51         args[i++] = "--stdin";
  52
  53         args[i] = NULL;
  54         execv_git_cmd(args);
  55         die("git-rev-list exec failed (%s)", strerror(errno));
  56 }
  57
  58 /*
  59  * Run "rev-list --stdin | pack-objects" pipe.
  60  */
  61 static void rev_list(struct ref *refs)
  62 {
  63         int pipe_fd[2];
  64         pid_t pack_objects_pid;
  65
  66         if (pipe(pipe_fd) < 0)
  67                 die("rev-list setup: pipe failed");
  68         pack_objects_pid = fork();
  69         if (!pack_objects_pid) {
  70                 /* The child becomes pack-objects; reads from pipe
  71                  * and writes to the original fd
  72                  */
  73                 dup2(pipe_fd[0], 0);
  74                 close(pipe_fd[0]);
  75                 close(pipe_fd[1]);
  76                 exec_pack_objects();
  77                 die("pack-objects setup failed");
  78         }
  79         if (pack_objects_pid < 0)
  80                 die("pack-objects fork failed");
  81
  82         /* We become rev-list --stdin; output goes to pipe. */
  83         dup2(pipe_fd[1], 1);
  84         close(pipe_fd[0]);
  85         close(pipe_fd[1]);
  86         exec_rev_list(refs);
  87 }
  88
  89 /*
  90  * Create "rev-list --stdin | pack-objects" pipe and feed
  91  * the refs into the pipeline.
  92  */
  93 static void rev_list_generate(int fd, struct ref *refs)
  94 {
  95         int pipe_fd[2];
  96         pid_t rev_list_generate_pid;
  97
  98         if (pipe(pipe_fd) < 0)
  99                 die("rev-list-generate setup: pipe failed");
 100         rev_list_generate_pid = fork();
 101         if (!rev_list_generate_pid) {
 102                 /* The child becomes the "rev-list | pack-objects"
 103                  * pipeline.  It takes input from us, and its output
 104                  * goes to fd.
 105                  */
 106                 dup2(pipe_fd[0], 0);
 107                 dup2(fd, 1);
 108                 close(pipe_fd[0]);
 109                 close(pipe_fd[1]);
 110                 close(fd);
 111                 rev_list(refs);
 112                 die("rev-list setup failed");
 113         }
 114         if (rev_list_generate_pid < 0)
 115                 die("rev-list-generate fork failed");
 116
 117         /* We feed the rev parameters to them.  We do not write into
 118          * fd nor read from the pipe.
 119          */
 120         close(pipe_fd[0]);
 121         close(fd);
 122         while (refs) {
 123                 char buf[42];
 124
 125                 if (!is_null_sha1(refs->old_sha1) &&
 126                     has_sha1_file(refs->old_sha1)) {
 127                         memcpy(buf + 1, sha1_to_hex(refs->old_sha1), 40);
 128                         buf[0] = '^';
 129                         buf[41] = '\n';
 130                         write(pipe_fd[1], buf, 42);
 131                 }
 132                 if (!is_null_sha1(refs->new_sha1)) {
 133                         memcpy(buf, sha1_to_hex(refs->new_sha1), 40);
 134                         buf[40] = '\n';
 135                         write(pipe_fd[1], buf, 41);
 136                 }
 137                 refs = refs->next;
 138         }
 139         close(pipe_fd[1]);
 140         // waitpid(rev_list_generate_pid);
 141         exit(0);
 142 }
 143
 144 /*
 145  * Make a pack stream and spit it out into file descriptor fd
 146  */
 147 static void pack_objects(int fd, struct ref *refs)
 148 {
 149         pid_t rev_list_pid;
 150
 151         rev_list_pid = fork();
 152         if (!rev_list_pid) {
 153                 rev_list_generate(fd, refs);
 154                 die("rev-list setup failed");
 155         }
 156         if (rev_list_pid < 0)
 157                 die("rev-list fork failed");
 158         /*
 159          * We don't wait for the rev-list pipeline in the parent:
 160          * we end up waiting for the other end instead
 161          */
 162 }
 163
 164 static void unmark_and_free(struct commit_list *list, unsigned int mark)
 165 {
 166         while (list) {
 167                 struct commit_list *temp = list;
 168                 temp->item->object.flags &= ~mark;
 169                 list = temp->next;
 170                 free(temp);
 171         }
 172 }
 173
 174 static int ref_newer(const unsigned char *new_sha1,
 175                      const unsigned char *old_sha1)
 176 {
 177         struct object *o;
 178         struct commit *old, *new;
 179         struct commit_list *list, *used;
 180         int found = 0;
 181
 182         /* Both new and old must be commit-ish and new is descendant of
 183          * old.  Otherwise we require --force.
 184          */
 185         o = deref_tag(parse_object(old_sha1), NULL, 0);
 186         if (!o || o->type != OBJ_COMMIT)
 187                 return 0;
 188         old = (struct commit *) o;
 189
 190         o = deref_tag(parse_object(new_sha1), NULL, 0);
 191         if (!o || o->type != OBJ_COMMIT)
 192                 return 0;
 193         new = (struct commit *) o;
 194
 195         if (parse_commit(new) < 0)
 196                 return 0;
 197
 198         used = list = NULL;
 199         commit_list_insert(new, &list);
 200         while (list) {
 201                 new = pop_most_recent_commit(&list, 1);
 202                 commit_list_insert(new, &used);
 203                 if (new == old) {
 204                         found = 1;
 205                         break;
 206                 }
 207         }
 208         unmark_and_free(list, 1);
 209         unmark_and_free(used, 1);
 210         return found;
 211 }
 212
 213 static struct ref *local_refs, **local_tail;
 214 static struct ref *remote_refs, **remote_tail;
 215
 216 static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 217 {
 218         struct ref *ref;
 219         int len = strlen(refname) + 1;
 220         ref = xcalloc(1, sizeof(*ref) + len);
 221         hashcpy(ref->new_sha1, sha1);
 222         memcpy(ref->name, refname, len);
 223         *local_tail = ref;
 224         local_tail = &ref->next;
 225         return 0;
 226 }
 227
 228 static void get_local_heads(void)
 229 {
 230         local_tail = &local_refs;
 231         for_each_ref(one_local_ref, NULL);
 232 }
 233
 234 static int receive_status(int in)
 235 {
 236         char line[1000];
 237         int ret = 0;
 238         int len = packet_read_line(in, line, sizeof(line));
 239         if (len < 10 || memcmp(line, "unpack ", 7)) {
 240                 fprintf(stderr, "did not receive status back\n");
 241                 return -1;
 242         }
 243         if (memcmp(line, "unpack ok\n", 10)) {
 244                 fputs(line, stderr);
 245                 ret = -1;
 246         }
 247         while (1) {
 248                 len = packet_read_line(in, line, sizeof(line));
 249                 if (!len)
 250                         break;
 251                 if (len < 3 ||
 252                     (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
 253                         fprintf(stderr, "protocol error: %s\n", line);
 254                         ret = -1;
 255                         break;
 256                 }
 257                 if (!memcmp(line, "ok", 2))
 258                         continue;
 259                 fputs(line, stderr);
 260                 ret = -1;
 261         }
 262         return ret;
 263 }
 264
 265 static int send_pack(int in, int out, int nr_refspec, char **refspec)
 266 {
 267         struct ref *ref;
 268         int new_refs;
 269         int ret = 0;
 270         int ask_for_status_report = 0;
 271         int allow_deleting_refs = 0;
 272         int expect_status_report = 0;
 273
 274         /* No funny business with the matcher */
 275         remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, REF_NORMAL);
 276         get_local_heads();
 277
 278         /* Does the other end support the reporting? */
 279         if (server_supports("report-status"))
 280                 ask_for_status_report = 1;
 281         if (server_supports("delete-refs"))
 282                 allow_deleting_refs = 1;
 283
 284         /* match them up */
 285         if (!remote_tail)
 286                 remote_tail = &remote_refs;
 287         if (match_refs(local_refs, remote_refs, &remote_tail,
 288                        nr_refspec, refspec, send_all))
 289                 return -1;
 290
 291         if (!remote_refs) {
 292                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
 293                 return 0;
 294         }
 295
 296         /*
 297          * Finally, tell the other end!
 298          */
 299         new_refs = 0;
 300         for (ref = remote_refs; ref; ref = ref->next) {
 301                 char old_hex[60], *new_hex;
 302                 int delete_ref;
 303
 304                 if (!ref->peer_ref)
 305                         continue;
 306
 307                 delete_ref = is_null_sha1(ref->peer_ref->new_sha1);
 308                 if (delete_ref && !allow_deleting_refs) {
 309                         error("remote does not support deleting refs");
 310                         ret = -2;
 311                         continue;
 312                 }
 313                 if (!delete_ref &&
 314                     !hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
 315                         if (verbose)
 316                                 fprintf(stderr, "'%s': up-to-date\n", ref->name);
 317                         continue;
 318                 }
 319
 320                 /* This part determines what can overwrite what.
 321                  * The rules are:
 322                  *
 323                  * (0) you can always use --force or +A:B notation to
 324                  *     selectively force individual ref pairs.
 325                  *
 326                  * (1) if the old thing does not exist, it is OK.
 327                  *
 328                  * (2) if you do not have the old thing, you are not allowed
 329                  *     to overwrite it; you would not know what you are losing
 330                  *     otherwise.
 331                  *
 332                  * (3) if both new and old are commit-ish, and new is a
 333                  *     descendant of old, it is OK.
 334                  *
 335                  * (4) regardless of all of the above, removing :B is
 336                  *     always allowed.
 337                  */
 338
 339                 if (!force_update &&
 340                     !delete_ref &&
 341                     !is_zero_sha1(ref->old_sha1) &&
 342                     !ref->force) {
 343                         if (!has_sha1_file(ref->old_sha1) ||
 344                             !ref_newer(ref->peer_ref->new_sha1,
 345                                        ref->old_sha1)) {
 346                                 /* We do not have the remote ref, or
 347                                  * we know that the remote ref is not
 348                                  * an ancestor of what we are trying to
 349                                  * push.  Either way this can be losing
 350                                  * commits at the remote end and likely
 351                                  * we were not up to date to begin with.
 352                                  */
 353                                 error("remote '%s' is not a strict "
 354                                       "subset of local ref '%s'. "
 355                                       "maybe you are not up-to-date and "
 356                                       "need to pull first?",
 357                                       ref->name,
 358                                       ref->peer_ref->name);
 359                                 ret = -2;
 360                                 continue;
 361                         }
 362                 }
 363                 hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
 364                 if (!delete_ref)
 365                         new_refs++;
 366                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 367                 new_hex = sha1_to_hex(ref->new_sha1);
 368
 369                 if (ask_for_status_report) {
 370                         packet_write(out, "%s %s %s%c%s",
 371                                      old_hex, new_hex, ref->name, 0,
 372                                      "report-status");
 373                         ask_for_status_report = 0;
 374                         expect_status_report = 1;
 375                 }
 376                 else
 377                         packet_write(out, "%s %s %s",
 378                                      old_hex, new_hex, ref->name);
 379                 if (delete_ref)
 380                         fprintf(stderr, "deleting '%s'\n", ref->name);
 381                 else {
 382                         fprintf(stderr, "updating '%s'", ref->name);
 383                         if (strcmp(ref->name, ref->peer_ref->name))
 384                                 fprintf(stderr, " using '%s'",
 385                                         ref->peer_ref->name);
 386                         fprintf(stderr, "\n  from %s\n  to   %s\n",
 387                                 old_hex, new_hex);
 388                 }
 389         }
 390
 391         packet_flush(out);
 392         if (new_refs)
 393                 pack_objects(out, remote_refs);
 394         close(out);
 395
 396         if (expect_status_report) {
 397                 if (receive_status(in))
 398                         ret = -4;
 399         }
 400
 401         if (!new_refs && ret == 0)
 402                 fprintf(stderr, "Everything up-to-date\n");
 403         return ret;
 404 }
 405
 406 static void verify_remote_names(int nr_heads, char **heads)
 407 {
 408         int i;
 409
 410         for (i = 0; i < nr_heads; i++) {
 411                 const char *remote = strchr(heads[i], ':');
 412
 413                 remote = remote ? (remote + 1) : heads[i];
 414                 switch (check_ref_format(remote)) {
 415                 case 0: /* ok */
 416                 case -2: /* ok but a single level -- that is fine for
 417                           * a match pattern.
 418                           */
 419                         continue;
 420                 }
 421                 die("remote part of refspec is not a valid name in %s",
 422                     heads[i]);
 423         }
 424 }
 425
 426 int main(int argc, char **argv)
 427 {
 428         int i, nr_heads = 0;
 429         char *dest = NULL;
 430         char **heads = NULL;
 431         int fd[2], ret;
 432         pid_t pid;
 433
 434         setup_git_directory();
 435         git_config(git_default_config);
 436
 437         argv++;
 438         for (i = 1; i < argc; i++, argv++) {
 439                 char *arg = *argv;
 440
 441                 if (*arg == '-') {
 442                         if (!strncmp(arg, "--exec=", 7)) {
 443                                 exec = arg + 7;
 444                                 continue;
 445                         }
 446                         if (!strcmp(arg, "--all")) {
 447                                 send_all = 1;
 448                                 continue;
 449                         }
 450                         if (!strcmp(arg, "--force")) {
 451                                 force_update = 1;
 452                                 continue;
 453                         }
 454                         if (!strcmp(arg, "--verbose")) {
 455                                 verbose = 1;
 456                                 continue;
 457                         }
 458                         if (!strcmp(arg, "--thin")) {
 459                                 use_thin_pack = 1;
 460                                 continue;
 461                         }
 462                         usage(send_pack_usage);
 463                 }
 464                 if (!dest) {
 465                         dest = arg;
 466                         continue;
 467                 }
 468                 heads = argv;
 469                 nr_heads = argc - i;
 470                 break;
 471         }
 472         if (!dest)
 473                 usage(send_pack_usage);
 474         if (heads && send_all)
 475                 usage(send_pack_usage);
 476         verify_remote_names(nr_heads, heads);
 477
 478         pid = git_connect(fd, dest, exec);
 479         if (pid < 0)
 480                 return 1;
 481         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 482         close(fd[0]);
 483         close(fd[1]);
 484         ret |= finish_connect(pid);
 485         return !!ret;
 486 }