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(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, int flag, void *cb_data)
 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, NULL);
 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 expect_status_report = 0;
 275
 276         /* No funny business with the matcher */
 277         remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, REF_NORMAL);
 278         get_local_heads();
 279
 280         /* Does the other end support the reporting? */
 281         if (server_supports("report-status"))
 282                 ask_for_status_report = 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                 if (!ref->peer_ref)
 303                         continue;
 304                 if (!hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
 305                         if (verbose)
 306                                 fprintf(stderr, "'%s': up-to-date\n", ref->name);
 307                         continue;
 308                 }
 309
 310                 /* This part determines what can overwrite what.
 311                  * The rules are:
 312                  *
 313                  * (0) you can always use --force or +A:B notation to
 314                  *     selectively force individual ref pairs.
 315                  *
 316                  * (1) if the old thing does not exist, it is OK.
 317                  *
 318                  * (2) if you do not have the old thing, you are not allowed
 319                  *     to overwrite it; you would not know what you are losing
 320                  *     otherwise.
 321                  *
 322                  * (3) if both new and old are commit-ish, and new is a
 323                  *     descendant of old, it is OK.
 324                  */
 325
 326                 if (!force_update &&
 327                     !is_zero_sha1(ref->old_sha1) &&
 328                     !ref->force) {
 329                         if (!has_sha1_file(ref->old_sha1) ||
 330                             !ref_newer(ref->peer_ref->new_sha1,
 331                                        ref->old_sha1)) {
 332                                 /* We do not have the remote ref, or
 333                                  * we know that the remote ref is not
 334                                  * an ancestor of what we are trying to
 335                                  * push.  Either way this can be losing
 336                                  * commits at the remote end and likely
 337                                  * we were not up to date to begin with.
 338                                  */
 339                                 error("remote '%s' is not a strict "
 340                                       "subset of local ref '%s'. "
 341                                       "maybe you are not up-to-date and "
 342                                       "need to pull first?",
 343                                       ref->name,
 344                                       ref->peer_ref->name);
 345                                 ret = -2;
 346                                 continue;
 347                         }
 348                 }
 349                 hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
 350                 if (is_zero_sha1(ref->new_sha1)) {
 351                         error("cannot happen anymore");
 352                         ret = -3;
 353                         continue;
 354                 }
 355                 new_refs++;
 356                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 357                 new_hex = sha1_to_hex(ref->new_sha1);
 358
 359                 if (ask_for_status_report) {
 360                         packet_write(out, "%s %s %s%c%s",
 361                                      old_hex, new_hex, ref->name, 0,
 362                                      "report-status");
 363                         ask_for_status_report = 0;
 364                         expect_status_report = 1;
 365                 }
 366                 else
 367                         packet_write(out, "%s %s %s",
 368                                      old_hex, new_hex, ref->name);
 369                 fprintf(stderr, "updating '%s'", ref->name);
 370                 if (strcmp(ref->name, ref->peer_ref->name))
 371                         fprintf(stderr, " using '%s'", ref->peer_ref->name);
 372                 fprintf(stderr, "\n  from %s\n  to   %s\n", old_hex, new_hex);
 373         }
 374
 375         packet_flush(out);
 376         if (new_refs)
 377                 pack_objects(out, remote_refs);
 378         close(out);
 379
 380         if (expect_status_report) {
 381                 if (receive_status(in))
 382                         ret = -4;
 383         }
 384
 385         if (!new_refs && ret == 0)
 386                 fprintf(stderr, "Everything up-to-date\n");
 387         return ret;
 388 }
 389
 390
 391 int main(int argc, char **argv)
 392 {
 393         int i, nr_heads = 0;
 394         char *dest = NULL;
 395         char **heads = NULL;
 396         int fd[2], ret;
 397         pid_t pid;
 398
 399         setup_git_directory();
 400         git_config(git_default_config);
 401
 402         argv++;
 403         for (i = 1; i < argc; i++, argv++) {
 404                 char *arg = *argv;
 405
 406                 if (*arg == '-') {
 407                         if (!strncmp(arg, "--exec=", 7)) {
 408                                 exec = arg + 7;
 409                                 continue;
 410                         }
 411                         if (!strcmp(arg, "--all")) {
 412                                 send_all = 1;
 413                                 continue;
 414                         }
 415                         if (!strcmp(arg, "--force")) {
 416                                 force_update = 1;
 417                                 continue;
 418                         }
 419                         if (!strcmp(arg, "--verbose")) {
 420                                 verbose = 1;
 421                                 continue;
 422                         }
 423                         if (!strcmp(arg, "--thin")) {
 424                                 use_thin_pack = 1;
 425                                 continue;
 426                         }
 427                         usage(send_pack_usage);
 428                 }
 429                 if (!dest) {
 430                         dest = arg;
 431                         continue;
 432                 }
 433                 heads = argv;
 434                 nr_heads = argc - i;
 435                 break;
 436         }
 437         if (!dest)
 438                 usage(send_pack_usage);
 439         if (heads && send_all)
 440                 usage(send_pack_usage);
 441         pid = git_connect(fd, dest, exec);
 442         if (pid < 0)
 443                 return 1;
 444         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 445         close(fd[0]);
 446         close(fd[1]);
 447         ret |= finish_connect(pid);
 448         return !!ret;
 449 }