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 = 0;
  13 static int send_all = 0;
  14 static int force_update = 0;
  15
  16 static int is_zero_sha1(const unsigned char *sha1)
  17 {
  18         int i;
  19
  20         for (i = 0; i < 20; i++) {
  21                 if (*sha1++)
  22                         return 0;
  23         }
  24         return 1;
  25 }
  26
  27 static void exec_pack_objects(void)
  28 {
  29         static char *args[] = {
  30                 "pack-objects",
  31                 "--stdout",
  32                 NULL
  33         };
  34         execv_git_cmd(args);
  35         die("git-pack-objects exec failed (%s)", strerror(errno));
  36 }
  37
  38 static void exec_rev_list(struct ref *refs)
  39 {
  40         static char *args[1000];
  41         int i = 0;
  42
  43         args[i++] = "rev-list"; /* 0 */
  44         args[i++] = "--objects";        /* 1 */
  45         while (refs) {
  46                 char *buf = malloc(100);
  47                 if (i > 900)
  48                         die("git-rev-list environment overflow");
  49                 if (!is_zero_sha1(refs->old_sha1) &&
  50                     has_sha1_file(refs->old_sha1)) {
  51                         args[i++] = buf;
  52                         snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
  53                         buf += 50;
  54                 }
  55                 if (!is_zero_sha1(refs->new_sha1)) {
  56                         args[i++] = buf;
  57                         snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
  58                 }
  59                 refs = refs->next;
  60         }
  61         args[i] = NULL;
  62         execv_git_cmd(args);
  63         die("git-rev-list exec failed (%s)", strerror(errno));
  64 }
  65
  66 static void rev_list(int fd, struct ref *refs)
  67 {
  68         int pipe_fd[2];
  69         pid_t pack_objects_pid;
  70
  71         if (pipe(pipe_fd) < 0)
  72                 die("rev-list setup: pipe failed");
  73         pack_objects_pid = fork();
  74         if (!pack_objects_pid) {
  75                 dup2(pipe_fd[0], 0);
  76                 dup2(fd, 1);
  77                 close(pipe_fd[0]);
  78                 close(pipe_fd[1]);
  79                 close(fd);
  80                 exec_pack_objects();
  81                 die("pack-objects setup failed");
  82         }
  83         if (pack_objects_pid < 0)
  84                 die("pack-objects fork failed");
  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 static int pack_objects(int fd, struct ref *refs)
  93 {
  94         pid_t rev_list_pid;
  95
  96         rev_list_pid = fork();
  97         if (!rev_list_pid) {
  98                 rev_list(fd, refs);
  99                 die("rev-list setup failed");
 100         }
 101         if (rev_list_pid < 0)
 102                 die("rev-list fork failed");
 103         /*
 104          * We don't wait for the rev-list pipeline in the parent:
 105          * we end up waiting for the other end instead
 106          */
 107         return 0;
 108 }
 109
 110 static void unmark_and_free(struct commit_list *list, unsigned int mark)
 111 {
 112         while (list) {
 113                 struct commit_list *temp = list;
 114                 temp->item->object.flags &= ~mark;
 115                 list = temp->next;
 116                 free(temp);
 117         }
 118 }
 119
 120 static int ref_newer(const unsigned char *new_sha1,
 121                      const unsigned char *old_sha1)
 122 {
 123         struct object *o;
 124         struct commit *old, *new;
 125         struct commit_list *list, *used;
 126         int found = 0;
 127
 128         /* Both new and old must be commit-ish and new is descendant of
 129          * old.  Otherwise we require --force.
 130          */
 131         o = deref_tag(parse_object(old_sha1), NULL, 0);
 132         if (!o || o->type != commit_type)
 133                 return 0;
 134         old = (struct commit *) o;
 135
 136         o = deref_tag(parse_object(new_sha1), NULL, 0);
 137         if (!o || o->type != commit_type)
 138                 return 0;
 139         new = (struct commit *) o;
 140
 141         if (parse_commit(new) < 0)
 142                 return 0;
 143
 144         used = list = NULL;
 145         commit_list_insert(new, &list);
 146         while (list) {
 147                 new = pop_most_recent_commit(&list, 1);
 148                 commit_list_insert(new, &used);
 149                 if (new == old) {
 150                         found = 1;
 151                         break;
 152                 }
 153         }
 154         unmark_and_free(list, 1);
 155         unmark_and_free(used, 1);
 156         return found;
 157 }
 158
 159 static struct ref *local_refs, **local_tail;
 160 static struct ref *remote_refs, **remote_tail;
 161
 162 static int one_local_ref(const char *refname, const unsigned char *sha1)
 163 {
 164         struct ref *ref;
 165         int len = strlen(refname) + 1;
 166         ref = xcalloc(1, sizeof(*ref) + len);
 167         memcpy(ref->new_sha1, sha1, 20);
 168         memcpy(ref->name, refname, len);
 169         *local_tail = ref;
 170         local_tail = &ref->next;
 171         return 0;
 172 }
 173
 174 static void get_local_heads(void)
 175 {
 176         local_tail = &local_refs;
 177         for_each_ref(one_local_ref);
 178 }
 179
 180 static int receive_status(int in)
 181 {
 182         char line[1000];
 183         int ret = 0;
 184         int len = packet_read_line(in, line, sizeof(line));
 185         if (len < 10 || memcmp(line, "unpack ", 7)) {
 186                 fprintf(stderr, "did not receive status back\n");
 187                 return -1;
 188         }
 189         if (memcmp(line, "unpack ok\n", 10)) {
 190                 fputs(line, stderr);
 191                 ret = -1;
 192         }
 193         while (1) {
 194                 len = packet_read_line(in, line, sizeof(line));
 195                 if (!len)
 196                         break;
 197                 if (len < 3 ||
 198                     (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
 199                         fprintf(stderr, "protocol error: %s\n", line);
 200                         ret = -1;
 201                         break;
 202                 }
 203                 if (!memcmp(line, "ok", 2))
 204                         continue;
 205                 fputs(line, stderr);
 206                 ret = -1;
 207         }
 208         return ret;
 209 }
 210
 211 static int send_pack(int in, int out, int nr_refspec, char **refspec)
 212 {
 213         struct ref *ref;
 214         int new_refs;
 215         int ret = 0;
 216         int ask_for_status_report = 0;
 217         int expect_status_report = 0;
 218
 219         /* No funny business with the matcher */
 220         remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, 1);
 221         get_local_heads();
 222
 223         /* Does the other end support the reporting? */
 224         if (server_supports("report-status"))
 225                 ask_for_status_report = 1;
 226
 227         /* match them up */
 228         if (!remote_tail)
 229                 remote_tail = &remote_refs;
 230         if (match_refs(local_refs, remote_refs, &remote_tail,
 231                        nr_refspec, refspec, send_all))
 232                 return -1;
 233
 234         if (!remote_refs) {
 235                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
 236                 return 0;
 237         }
 238
 239         /*
 240          * Finally, tell the other end!
 241          */
 242         new_refs = 0;
 243         for (ref = remote_refs; ref; ref = ref->next) {
 244                 char old_hex[60], *new_hex;
 245                 if (!ref->peer_ref)
 246                         continue;
 247                 if (!memcmp(ref->old_sha1, ref->peer_ref->new_sha1, 20)) {
 248                         if (verbose)
 249                                 fprintf(stderr, "'%s': up-to-date\n", ref->name);
 250                         continue;
 251                 }
 252
 253                 /* This part determines what can overwrite what.
 254                  * The rules are:
 255                  *
 256                  * (0) you can always use --force or +A:B notation to
 257                  *     selectively force individual ref pairs.
 258                  *
 259                  * (1) if the old thing does not exist, it is OK.
 260                  *
 261                  * (2) if you do not have the old thing, you are not allowed
 262                  *     to overwrite it; you would not know what you are losing
 263                  *     otherwise.
 264                  *
 265                  * (3) if both new and old are commit-ish, and new is a
 266                  *     descendant of old, it is OK.
 267                  */
 268
 269                 if (!force_update &&
 270                     !is_zero_sha1(ref->old_sha1) &&
 271                     !ref->force) {
 272                         if (!has_sha1_file(ref->old_sha1) ||
 273                             !ref_newer(ref->peer_ref->new_sha1,
 274                                        ref->old_sha1)) {
 275                                 /* We do not have the remote ref, or
 276                                  * we know that the remote ref is not
 277                                  * an ancestor of what we are trying to
 278                                  * push.  Either way this can be losing
 279                                  * commits at the remote end and likely
 280                                  * we were not up to date to begin with.
 281                                  */
 282                                 error("remote '%s' is not a strict "
 283                                       "subset of local ref '%s'. "
 284                                       "maybe you are not up-to-date and "
 285                                       "need to pull first?",
 286                                       ref->name,
 287                                       ref->peer_ref->name);
 288                                 ret = -2;
 289                                 continue;
 290                         }
 291                 }
 292                 memcpy(ref->new_sha1, ref->peer_ref->new_sha1, 20);
 293                 if (is_zero_sha1(ref->new_sha1)) {
 294                         error("cannot happen anymore");
 295                         ret = -3;
 296                         continue;
 297                 }
 298                 new_refs++;
 299                 strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 300                 new_hex = sha1_to_hex(ref->new_sha1);
 301
 302                 if (ask_for_status_report) {
 303                         packet_write(out, "%s %s %s%c%s",
 304                                      old_hex, new_hex, ref->name, 0,
 305                                      "report-status");
 306                         ask_for_status_report = 0;
 307                         expect_status_report = 1;
 308                 }
 309                 else
 310                         packet_write(out, "%s %s %s",
 311                                      old_hex, new_hex, ref->name);
 312                 fprintf(stderr, "updating '%s'", ref->name);
 313                 if (strcmp(ref->name, ref->peer_ref->name))
 314                         fprintf(stderr, " using '%s'", ref->peer_ref->name);
 315                 fprintf(stderr, "\n  from %s\n  to   %s\n", old_hex, new_hex);
 316         }
 317
 318         packet_flush(out);
 319         if (new_refs)
 320                 pack_objects(out, remote_refs);
 321         close(out);
 322
 323         if (expect_status_report) {
 324                 if (receive_status(in))
 325                         ret = -4;
 326         }
 327
 328         if (!new_refs && ret == 0)
 329                 fprintf(stderr, "Everything up-to-date\n");
 330         return ret;
 331 }
 332
 333
 334 int main(int argc, char **argv)
 335 {
 336         int i, nr_heads = 0;
 337         char *dest = NULL;
 338         char **heads = NULL;
 339         int fd[2], ret;
 340         pid_t pid;
 341
 342         setup_git_directory();
 343         argv++;
 344         for (i = 1; i < argc; i++, argv++) {
 345                 char *arg = *argv;
 346
 347                 if (*arg == '-') {
 348                         if (!strncmp(arg, "--exec=", 7)) {
 349                                 exec = arg + 7;
 350                                 continue;
 351                         }
 352                         if (!strcmp(arg, "--all")) {
 353                                 send_all = 1;
 354                                 continue;
 355                         }
 356                         if (!strcmp(arg, "--force")) {
 357                                 force_update = 1;
 358                                 continue;
 359                         }
 360                         if (!strcmp(arg, "--verbose")) {
 361                                 verbose = 1;
 362                                 continue;
 363                         }
 364                         usage(send_pack_usage);
 365                 }
 366                 if (!dest) {
 367                         dest = arg;
 368                         continue;
 369                 }
 370                 heads = argv;
 371                 nr_heads = argc - i;
 372                 break;
 373         }
 374         if (!dest)
 375                 usage(send_pack_usage);
 376         if (heads && send_all)
 377                 usage(send_pack_usage);
 378         pid = git_connect(fd, dest, exec);
 379         if (pid < 0)
 380                 return 1;
 381         ret = send_pack(fd[0], fd[1], nr_heads, heads);
 382         close(fd[0]);
 383         close(fd[1]);
 384         finish_connect(pid);
 385         return ret;
 386 }