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] [--keep] [--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 static int keep_pack;
  17
  18 static int is_zero_sha1(const unsigned char *sha1)
  19 {
  20         int i;
  21
  22         for (i = 0; i < 20; i++) {
  23                 if (*sha1++)
  24                         return 0;
  25         }
  26         return 1;
  27 }
  28
  29 static void exec_pack_objects(void)
  30 {
  31         static const char *args[] = {
  32                 "pack-objects",
  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(int fd, 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                 dup2(fd, 1);
  75                 close(pipe_fd[0]);
  76                 close(pipe_fd[1]);
  77                 close(fd);
  78                 exec_pack_objects();
  79                 die("pack-objects setup failed");
  80         }
  81         if (pack_objects_pid < 0)
  82                 die("pack-objects fork failed");
  83
  84         /* We become rev-list --stdin; output goes to pipe. */
  85         dup2(pipe_fd[1], 1);
  86         close(pipe_fd[0]);
  87         close(pipe_fd[1]);
  88         close(fd);
  89         exec_rev_list(refs);
  90 }
  91
  92 /*
  93  * Create "rev-list --stdin | pack-objects" pipe and feed
  94  * the refs into the pipeline.
  95  */
  96 static void rev_list_generate(int fd, struct ref *refs)
  97 {
  98         int pipe_fd[2];
  99         pid_t rev_list_generate_pid;
 100
 101         if (pipe(pipe_fd) < 0)
 102                 die("rev-list-generate setup: pipe failed");
 103         rev_list_generate_pid = fork();
 104         if (!rev_list_generate_pid) {
 105                 /* The child becomes the "rev-list | pack-objects"
 106                  * pipeline.  It takes input from us, and its output
 107                  * goes to fd.
 108                  */
 109                 dup2(pipe_fd[0], 0);
 110                 dup2(fd, 1);
 111                 close(pipe_fd[0]);
 112                 close(pipe_fd[1]);
 113                 close(fd);
 114                 rev_list(fd, refs);
 115                 die("rev-list setup failed");
 116         }
 117         if (rev_list_generate_pid < 0)
 118                 die("rev-list-generate fork failed");
 119
 120         /* We feed the rev parameters to them.  We do not write into
 121          * fd nor read from the pipe.
 122          */
 123         close(pipe_fd[0]);
 124         close(fd);
 125         while (refs) {
 126                 char buf[42];
 127
 128                 if (!is_null_sha1(refs->old_sha1) &&
 129                     has_sha1_file(refs->old_sha1)) {
 130                         memcpy(buf + 1, sha1_to_hex(refs->old_sha1), 40);
 131                         buf[0] = '^';
 132                         buf[41] = '\n';
 133                         write(pipe_fd[1], buf, 42);
 134                 }
 135                 if (!is_null_sha1(refs->new_sha1)) {
 136                         memcpy(buf, sha1_to_hex(refs->new_sha1), 40);
 137                         buf[40] = '\n';
 138                         write(pipe_fd[1], buf, 41);
 139                 }
 140                 refs = refs->next;
 141         }
 142         close(pipe_fd[1]);
 143         // waitpid(rev_list_generate_pid);
 144         exit(0);
 145 }
 146
 147 /*
 148  * Make a pack stream and spit it out into file descriptor fd
 149  */
 150 static void pack_objects(int fd, struct ref *refs)
 151 {
 152         pid_t rev_list_pid;
 153
 154         rev_list_pid = fork();
 155         if (!rev_list_pid) {
 156                 rev_list_generate(fd, refs);
 157                 die("rev-list setup failed");
 158         }
 159         if (rev_list_pid < 0)
 160                 die("rev-list fork failed");
 161         /*
 162          * We don't wait for the rev-list pipeline in the parent:
 163          * we end up waiting for the other end instead
 164          */
 165 }
 166
 167 static void unmark_and_free(struct commit_list *list, unsigned int mark)
 168 {
 169         while (list) {
 170                 struct commit_list *temp = list;
 171                 temp->item->object.flags &= ~mark;
 172                 list = temp->next;
 173                 free(temp);
 174         }
 175 }
 176
 177 static int ref_newer(const unsigned char *new_sha1,
 178                      const unsigned char *old_sha1)
 179 {
 180         struct object *o;
 181         struct commit *old, *new;
 182         struct commit_list *list, *used;
 183         int found = 0;
 184
 185         /* Both new and old must be commit-ish and new is descendant of
 186          * old.  Otherwise we require --force.
 187          */
 188         o = deref_tag(parse_object(old_sha1), NULL, 0);
 189         if (!o || o->type != OBJ_COMMIT)
 190                 return 0;
 191         old = (struct commit *) o;
 192
 193         o = deref_tag(parse_object(new_sha1), NULL, 0);
 194         if (!o || o->type != OBJ_COMMIT)
 195                 return 0;
 196         new = (struct commit *) o;
 197
 198         if (parse_commit(new) < 0)
 199                 return 0;
 200
 201         used = list = NULL;
 202         commit_list_insert(new, &list);
 203         while (list) {
 204                 new = pop_most_recent_commit(&list, 1);
 205                 commit_list_insert(new, &used);
 206                 if (new == old) {
 207                         found = 1;
 208                         break;
 209                 }
 210         }
 211         unmark_and_free(list, 1);
 212         unmark_and_free(used, 1);
 213         return found;
 214 }
 215
 216 static struct ref *local_refs, **local_tail;
 217 static struct ref *remote_refs, **remote_tail;
 218
 219 static int one_local_ref(const char *refname, const unsigned char *sha1)
 220 {
 221         struct ref *ref;
 222         int len = strlen(refname) + 1;
 223         ref = xcalloc(1, sizeof(*ref) + len);
 224         hashcpy(ref->new_sha1, sha1);
 225         memcpy(ref->name, refname, len);
 226         *local_tail = ref;
 227         local_tail = &ref->next;
 228         return 0;
 229 }
 230
 231 static void get_local_heads(void)
 232 {
 233         local_tail = &local_refs;
 234         for_each_ref(one_local_ref);
 235 }
 236
 237 static int receive_status(int in)
 238 {
 239         char line[1000];
 240         int ret = 0;
 241         int len = packet_read_line(in, line, sizeof(line));
 242         if (len < 10 || memcmp(line, "unpack ", 7)) {
 243                 fprintf(stderr, "did not receive status back\n");
 244                 return -1;
 245         }
 246         if (memcmp(line, "unpack ok\n", 10)) {
 247                 fputs(line, stderr);
 248                 ret = -1;
 249         }
 250         while (1) {
 251                 len = packet_read_line(in, line, sizeof(line));
 252                 if (!len)
 253                         break;
 254                 if (len < 3 ||
 255                     (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
 256                         fprintf(stderr, "protocol error: %s\n", line);
 257                         ret = -1;
 258                         break;
 259                 }
 260                 if (!memcmp(line, "ok", 2))
 261                         continue;
 262                 fputs(line, stderr);
 263                 ret = -1;
 264         }
 265         return ret;
 266 }
 267
 268 static int send_pack(int in, int out, int nr_refspec, char **refspec)
 269 {
 270         struct ref *ref;
 271         int new_refs;
 272         int ret = 0;
 273         int ask_for_status_report = 0;
 274         int ask_to_keep_pack = 0;
 275         int expect_status_report = 0;
 276
 277         /* No funny business with the matcher */
 278         remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, REF_NORMAL);
 279         get_local_heads();
 280
 281         /* Does the other end support the reporting? */
 282         if (server_supports("report-status"))
 283                 ask_for_status_report = 1;
 284         if (server_supports("keep-pack") && keep_pack)
 285                 ask_to_keep_pack = 1;
 286
 287         /* match them up */
 288         if (!remote_tail)
 289                 remote_tail = &remote_refs;
 290         if (match_refs(local_refs, remote_refs, &remote_tail,
 291                        nr_refspec, refspec, send_all))
 292                 return -1;
 293
 294         if (!remote_refs) {
 295                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
 296                 return 0;
 297         }
 298
 299         /*
 300          * Finally, tell the other end!
 301          */
 302         new_refs = 0;
 303         for (ref = remote_refs; ref; ref = ref->next) {
 304                 char old_hex[60], *new_hex;
 305                 if (!ref->peer_ref)
 306                         continue;
 307                 if (!hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
 308                         if (verbose)
 309                                 fprintf(stderr, "'%s': up-to-date\n", ref->name);
 310                         continue;
 311                 }
 312
 313                 /* This part determines what can overwrite what.
 314                  * The rules are:
 315                  *
 316                  * (0) you can always use --force or +A:B notation to
 317                  *     selectively force individual ref pairs.
 318                  *
 319                  * (1) if the old thing does not exist, it is OK.
 320                  *
 321                  * (2) if you do not have the old thing, you are not allowed
 322                  *     to overwrite it; you would not know what you are losing
 323                  *     otherwise.
 324                  *
 325                  * (3) if both new and old are commit-ish, and new is a
 326                  *     descendant of old, it is OK.
 327                  */
 328
 329                 if (!force_update &&
 330                     !is_zero_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 (is_zero_sha1(ref->new_sha1)) {
 354                         error("cannot happen anymore");
 355                         ret = -3;
 356                         continue;
 357                 }
 358                 new_refs++;
 359                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 360                 new_hex = sha1_to_hex(ref->new_sha1);
 361
 362                 if (ask_for_status_report || ask_to_keep_pack) {
 363                         packet_write(out, "%s %s %s%c%s%s",
 364                                      old_hex, new_hex, ref->name, 0,
 365                                      ask_for_status_report
 366                                      ? " report-status" : "",
 367                                      ask_to_keep_pack
 368                                      ? " keep-pack" : "");
 369                         if (ask_for_status_report)
 370                                 expect_status_report = 1;
 371                         ask_for_status_report = 0;
 372                         ask_to_keep_pack = 0;
 373                 }
 374                 else
 375                         packet_write(out, "%s %s %s",
 376                                      old_hex, new_hex, ref->name);
 377                 fprintf(stderr, "updating '%s'", ref->name);
 378                 if (strcmp(ref->name, ref->peer_ref->name))
 379                         fprintf(stderr, " using '%s'", ref->peer_ref->name);
 380                 fprintf(stderr, "\n  from %s\n  to   %s\n", old_hex, new_hex);
 381         }
 382
 383         packet_flush(out);
 384         if (new_refs)
 385                 pack_objects(out, remote_refs);
 386         close(out);
 387
 388         if (expect_status_report) {
 389                 if (receive_status(in))
 390                         ret = -4;
 391         }
 392
 393         if (!new_refs && ret == 0)
 394                 fprintf(stderr, "Everything up-to-date\n");
 395         return ret;
 396 }
 397
 398
 399 int main(int argc, char **argv)
 400 {
 401         int i, nr_heads = 0;
 402         char *dest = NULL;
 403         char **heads = NULL;
 404         int fd[2], ret;
 405         pid_t pid;
 406
 407         setup_git_directory();
 408         git_config(git_default_config);
 409
 410         argv++;
 411         for (i = 1; i < argc; i++, argv++) {
 412                 char *arg = *argv;
 413
 414                 if (*arg == '-') {
 415                         if (!strncmp(arg, "--exec=", 7)) {
 416                                 exec = arg + 7;
 417                                 continue;
 418                         }
 419                         if (!strcmp(arg, "--all")) {
 420                                 send_all = 1;
 421                                 continue;
 422                         }
 423                         if (!strcmp(arg, "--force")) {
 424                                 force_update = 1;
 425                                 continue;
 426                         }
 427                         if (!strcmp(arg, "--verbose")) {
 428                                 verbose = 1;
 429                                 continue;
 430                         }
 431                         if (!strcmp(arg, "--keep")) {
 432                                 keep_pack = 1;
 433                                 continue;
 434                         }
 435                         if (!strcmp(arg, "--thin")) {
 436                                 use_thin_pack = 1;
 437                                 continue;
 438                         }
 439                         usage(send_pack_usage);
 440                 }
 441                 if (!dest) {
 442                         dest = arg;
 443                         continue;
 444                 }
 445                 heads = argv;
 446                 nr_heads = argc - i;
 447                 break;
 448         }
 449         if (!dest)
 450                 usage(send_pack_usage);
 451         if (heads && send_all)
 452                 usage(send_pack_usage);
 453         pid = git_connect(fd, dest, exec);
 454         if (pid < 0)
 455                 return 1;
 456         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 457         close(fd[0]);
 458         close(fd[1]);
 459         ret |= finish_connect(pid);
 460         return !!ret;
 461 }