clone-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4 #include <sys/wait.h>
   5
   6 static int quiet;
   7 static int keep_pack;
   8 static const char clone_pack_usage[] =
   9 "git-clone-pack [-q] [--keep] [--exec=<git-upload-pack>] [<host>:]<directory> [<heads>]*";
  10 static const char *exec = "git-upload-pack";
  11
  12 static void clone_handshake(int fd[2], struct ref *ref)
  13 {
  14         unsigned char sha1[20];
  15
  16         while (ref) {
  17                 packet_write(fd[1], "want %s\n", sha1_to_hex(ref->old_sha1));
  18                 ref = ref->next;
  19         }
  20         packet_flush(fd[1]);
  21
  22         /* We don't have nuttin' */
  23         packet_write(fd[1], "done\n");
  24         if (get_ack(fd[0], sha1))
  25                 error("Huh! git-clone-pack got positive ack for %s", sha1_to_hex(sha1));
  26 }
  27
  28 static int is_master(struct ref *ref)
  29 {
  30         return !strcmp(ref->name, "refs/heads/master");
  31 }
  32
  33 static void write_one_ref(struct ref *ref)
  34 {
  35         char *path = git_path("%s", ref->name);
  36         int fd;
  37         char *hex;
  38
  39         if (!strncmp(ref->name, "refs/", 5) &&
  40             check_ref_format(ref->name + 5)) {
  41                 error("refusing to create funny ref '%s' locally", ref->name);
  42                 return;
  43         }
  44
  45         if (safe_create_leading_directories(path))
  46                 die("unable to create leading directory for %s", ref->name);
  47         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, 0666);
  48         if (fd < 0)
  49                 die("unable to create ref %s", ref->name);
  50         hex = sha1_to_hex(ref->old_sha1);
  51         hex[40] = '\n';
  52         if (write(fd, hex, 41) != 41)
  53                 die("unable to write ref %s", ref->name);
  54         close(fd);
  55 }
  56
  57 static void write_refs(struct ref *ref)
  58 {
  59         struct ref *head = NULL, *head_ptr, *master_ref;
  60         char *head_path;
  61
  62         /* Upload-pack must report HEAD first */
  63         if (!strcmp(ref->name, "HEAD")) {
  64                 head = ref;
  65                 ref = ref->next;
  66         }
  67         head_ptr = NULL;
  68         master_ref = NULL;
  69         while (ref) {
  70                 if (is_master(ref))
  71                         master_ref = ref;
  72                 if (head &&
  73                     !memcmp(ref->old_sha1, head->old_sha1, 20) &&
  74                     !strncmp(ref->name, "refs/heads/",11) &&
  75                     (!head_ptr || ref == master_ref))
  76                         head_ptr = ref;
  77
  78                 write_one_ref(ref);
  79                 ref = ref->next;
  80         }
  81         if (!head) {
  82                 fprintf(stderr, "No HEAD in remote.\n");
  83                 return;
  84         }
  85
  86         head_path = strdup(git_path("HEAD"));
  87         if (!head_ptr) {
  88                 /*
  89                  * If we had a master ref, and it wasn't HEAD, we need to undo the
  90                  * symlink, and write a standalone HEAD. Give a warning, because that's
  91                  * really really wrong.
  92                  */
  93                 if (master_ref) {
  94                         error("HEAD doesn't point to any refs! Making standalone HEAD");
  95                         unlink(head_path);
  96                 }
  97                 write_one_ref(head);
  98                 free(head_path);
  99                 return;
 100         }
 101
 102         /* We reset to the master branch if it's available */
 103         if (master_ref)
 104                 return;
 105
 106         fprintf(stderr, "Setting HEAD to %s\n", head_ptr->name);
 107
 108         /*
 109          * Uhhuh. Other end didn't have master. We start HEAD off with
 110          * the first branch with the same value.
 111          */
 112         if (create_symref(head_path, head_ptr->name) < 0)
 113                 die("unable to link HEAD to %s", head_ptr->name);
 114         free(head_path);
 115 }
 116
 117 static int clone_by_unpack(int fd[2])
 118 {
 119         int status;
 120         pid_t pid;
 121
 122         pid = fork();
 123         if (pid < 0)
 124                 die("git-clone-pack: unable to fork off git-unpack-objects");
 125         if (!pid) {
 126                 dup2(fd[0], 0);
 127                 close(fd[0]);
 128                 close(fd[1]);
 129                 execlp("git-unpack-objects", "git-unpack-objects",
 130                         quiet ? "-q" : NULL, NULL);
 131                 die("git-unpack-objects exec failed");
 132         }
 133         close(fd[0]);
 134         close(fd[1]);
 135         while (waitpid(pid, &status, 0) < 0) {
 136                 if (errno != EINTR)
 137                         die("waiting for git-unpack-objects: %s", strerror(errno));
 138         }
 139         if (WIFEXITED(status)) {
 140                 int code = WEXITSTATUS(status);
 141                 if (code)
 142                         die("git-unpack-objects died with error code %d", code);
 143                 return 0;
 144         }
 145         if (WIFSIGNALED(status)) {
 146                 int sig = WTERMSIG(status);
 147                 die("git-unpack-objects died of signal %d", sig);
 148         }
 149         die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
 150 }
 151
 152 static int finish_pack(const char *pack_tmp_name)
 153 {
 154         int pipe_fd[2];
 155         pid_t pid;
 156         char idx[PATH_MAX];
 157         char final[PATH_MAX];
 158         char hash[41];
 159         unsigned char sha1[20];
 160         char *cp;
 161         int err = 0;
 162
 163         if (pipe(pipe_fd) < 0)
 164                 die("git-clone-pack: unable to set up pipe");
 165
 166         strcpy(idx, pack_tmp_name); /* ".git/objects/pack-XXXXXX" */
 167         cp = strrchr(idx, '/');
 168         memcpy(cp, "/pidx", 5);
 169
 170         pid = fork();
 171         if (pid < 0)
 172                 die("git-clone-pack: unable to fork off git-index-pack");
 173         if (!pid) {
 174                 close(0);
 175                 dup2(pipe_fd[1], 1);
 176                 close(pipe_fd[0]);
 177                 close(pipe_fd[1]);
 178                 execlp("git-index-pack","git-index-pack",
 179                        "-o", idx, pack_tmp_name, NULL);
 180                 error("cannot exec git-index-pack <%s> <%s>",
 181                       idx, pack_tmp_name);
 182                 exit(1);
 183         }
 184         close(pipe_fd[1]);
 185         if (read(pipe_fd[0], hash, 40) != 40) {
 186                 error("git-clone-pack: unable to read from git-index-pack");
 187                 err = 1;
 188         }
 189         close(pipe_fd[0]);
 190
 191         for (;;) {
 192                 int status, code;
 193                 int retval = waitpid(pid, &status, 0);
 194
 195                 if (retval < 0) {
 196                         if (errno == EINTR)
 197                                 continue;
 198                         error("waitpid failed (%s)", strerror(retval));
 199                         goto error_die;
 200                 }
 201                 if (WIFSIGNALED(status)) {
 202                         int sig = WTERMSIG(status);
 203                         error("git-index-pack died of signal %d", sig);
 204                         goto error_die;
 205                 }
 206                 if (!WIFEXITED(status)) {
 207                         error("git-index-pack died of unnatural causes %d",
 208                               status);
 209                         goto error_die;
 210                 }
 211                 code = WEXITSTATUS(status);
 212                 if (code) {
 213                         error("git-index-pack died with error code %d", code);
 214                         goto error_die;
 215                 }
 216                 if (err)
 217                         goto error_die;
 218                 break;
 219         }
 220         hash[40] = 0;
 221         if (get_sha1_hex(hash, sha1)) {
 222                 error("git-index-pack reported nonsense '%s'", hash);
 223                 goto error_die;
 224         }
 225         /* Now we have pack in pack_tmp_name[], and
 226          * idx in idx[]; rename them to their final names.
 227          */
 228         snprintf(final, sizeof(final),
 229                  "%s/pack/pack-%s.pack", get_object_directory(), hash);
 230         move_temp_to_file(pack_tmp_name, final);
 231         chmod(final, 0444);
 232         snprintf(final, sizeof(final),
 233                  "%s/pack/pack-%s.idx", get_object_directory(), hash);
 234         move_temp_to_file(idx, final);
 235         chmod(final, 0444);
 236         return 0;
 237
 238  error_die:
 239         unlink(idx);
 240         unlink(pack_tmp_name);
 241         exit(1);
 242 }
 243
 244 static int clone_without_unpack(int fd[2])
 245 {
 246         char tmpfile[PATH_MAX];
 247         int ofd, ifd;
 248
 249         ifd = fd[0];
 250         snprintf(tmpfile, sizeof(tmpfile),
 251                  "%s/pack-XXXXXX", get_object_directory());
 252         ofd = mkstemp(tmpfile);
 253         if (ofd < 0)
 254                 return error("unable to create temporary file %s", tmpfile);
 255
 256         while (1) {
 257                 char buf[8192];
 258                 ssize_t sz, wsz, pos;
 259                 sz = read(ifd, buf, sizeof(buf));
 260                 if (sz == 0)
 261                         break;
 262                 if (sz < 0) {
 263                         error("error reading pack (%s)", strerror(errno));
 264                         close(ofd);
 265                         unlink(tmpfile);
 266                         return -1;
 267                 }
 268                 pos = 0;
 269                 while (pos < sz) {
 270                         wsz = write(ofd, buf + pos, sz - pos);
 271                         if (wsz < 0) {
 272                                 error("error writing pack (%s)",
 273                                       strerror(errno));
 274                                 close(ofd);
 275                                 unlink(tmpfile);
 276                                 return -1;
 277                         }
 278                         pos += wsz;
 279                 }
 280         }
 281         close(ofd);
 282         return finish_pack(tmpfile);
 283 }
 284
 285 static int clone_pack(int fd[2], int nr_match, char **match)
 286 {
 287         struct ref *refs;
 288         int status;
 289
 290         get_remote_heads(fd[0], &refs, nr_match, match);
 291         if (!refs) {
 292                 packet_flush(fd[1]);
 293                 die("no matching remote head");
 294         }
 295         clone_handshake(fd, refs);
 296
 297         if (keep_pack)
 298                 status = clone_without_unpack(fd);
 299         else
 300                 status = clone_by_unpack(fd);
 301
 302         if (!status)
 303                 write_refs(refs);
 304         return status;
 305 }
 306
 307 static int clone_options(const char *var, const char *value)
 308 {
 309         if (!strcmp("clone.keeppack", var)) {
 310                 keep_pack = git_config_bool(var, value);
 311                 return 0;
 312         }
 313         if (!strcmp("clone.quiet", var)) {
 314                 quiet = git_config_bool(var, value);
 315                 return 0;
 316         }
 317         /*
 318          * Put other local option parsing for this program
 319          * here ...
 320          */
 321
 322         /* Fall back on the default ones */
 323         return git_default_config(var, value);
 324 }
 325
 326 int main(int argc, char **argv)
 327 {
 328         int i, ret, nr_heads;
 329         char *dest = NULL, **heads;
 330         int fd[2];
 331         pid_t pid;
 332
 333         git_config(clone_options);
 334         nr_heads = 0;
 335         heads = NULL;
 336         for (i = 1; i < argc; i++) {
 337                 char *arg = argv[i];
 338
 339                 if (*arg == '-') {
 340                         if (!strcmp("-q", arg)) {
 341                                 quiet = 1;
 342                                 continue;
 343                         }
 344                         if (!strncmp("--exec=", arg, 7)) {
 345                                 exec = arg + 7;
 346                                 continue;
 347                         }
 348                         if (!strcmp("--keep", arg)) {
 349                                 keep_pack = 1;
 350                                 continue;
 351                         }
 352                         usage(clone_pack_usage);
 353                 }
 354                 dest = arg;
 355                 heads = argv + i + 1;
 356                 nr_heads = argc - i - 1;
 357                 break;
 358         }
 359         if (!dest)
 360                 usage(clone_pack_usage);
 361         pid = git_connect(fd, dest, exec);
 362         if (pid < 0)
 363                 return 1;
 364         ret = clone_pack(fd, nr_heads, heads);
 365         close(fd[0]);
 366         close(fd[1]);
 367         finish_connect(pid);
 368         return ret;
 369 }