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