upload-pack.c

   1 #include <signal.h>
   2 #include <sys/wait.h>
   3 #include <sys/poll.h>
   4 #include "cache.h"
   5 #include "refs.h"
   6 #include "pkt-line.h"
   7 #include "tag.h"
   8 #include "object.h"
   9 #include "commit.h"
  10 #include "exec_cmd.h"
  11
  12 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
  13
  14 #define THEY_HAVE (1U << 0)
  15 #define OUR_REF (1U << 1)
  16 #define WANTED (1U << 2)
  17 static int multi_ack = 0, nr_our_refs = 0;
  18 static int use_thin_pack = 0;
  19 static struct object_array have_obj;
  20 static struct object_array want_obj;
  21 static unsigned int timeout = 0;
  22 static int use_sideband = 0;
  23
  24 static void reset_timeout(void)
  25 {
  26         alarm(timeout);
  27 }
  28
  29 static int strip(char *line, int len)
  30 {
  31         if (len && line[len-1] == '\n')
  32                 line[--len] = 0;
  33         return len;
  34 }
  35
  36 #define PACKET_MAX 1000
  37 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
  38 {
  39         ssize_t ssz;
  40         const char *p;
  41
  42         if (!data) {
  43                 if (!use_sideband)
  44                         return 0;
  45                 packet_flush(1);
  46         }
  47
  48         if (!use_sideband) {
  49                 if (fd == 3)
  50                         /* emergency quit */
  51                         fd = 2;
  52                 return safe_write(fd, data, sz);
  53         }
  54         p = data;
  55         ssz = sz;
  56         while (sz) {
  57                 unsigned n;
  58                 char hdr[5];
  59
  60                 n = sz;
  61                 if (PACKET_MAX - 5 < n)
  62                         n = PACKET_MAX - 5;
  63                 sprintf(hdr, "%04x", n + 5);
  64                 hdr[4] = fd;
  65                 safe_write(1, hdr, 5);
  66                 safe_write(1, p, n);
  67                 p += n;
  68                 sz -= n;
  69         }
  70         return ssz;
  71 }
  72
  73 static void create_pack_file(void)
  74 {
  75         /* Pipes between rev-list to pack-objects, pack-objects to us
  76          * and pack-objects error stream for progress bar.
  77          */
  78         int lp_pipe[2], pu_pipe[2], pe_pipe[2];
  79         pid_t pid_rev_list, pid_pack_objects;
  80         int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
  81         char data[8193], progress[128];
  82         char abort_msg[] = "aborting due to possible repository "
  83                 "corruption on the remote side.";
  84         int buffered = -1;
  85
  86         if (pipe(lp_pipe) < 0)
  87                 die("git-upload-pack: unable to create pipe");
  88         pid_rev_list = fork();
  89         if (pid_rev_list < 0)
  90                 die("git-upload-pack: unable to fork git-rev-list");
  91
  92         if (!pid_rev_list) {
  93                 int i;
  94                 int args;
  95                 const char **argv;
  96                 const char **p;
  97                 char *buf;
  98
  99                 if (create_full_pack) {
 100                         args = 10;
 101                         use_thin_pack = 0; /* no point doing it */
 102                 }
 103                 else
 104                         args = have_obj.nr + want_obj.nr + 5;
 105                 p = xmalloc(args * sizeof(char *));
 106                 argv = (const char **) p;
 107                 buf = xmalloc(args * 45);
 108
 109                 dup2(lp_pipe[1], 1);
 110                 close(0);
 111                 close(lp_pipe[0]);
 112                 close(lp_pipe[1]);
 113                 *p++ = "rev-list";
 114                 *p++ = use_thin_pack ? "--objects-edge" : "--objects";
 115                 if (create_full_pack)
 116                         *p++ = "--all";
 117                 else {
 118                         for (i = 0; i < want_obj.nr; i++) {
 119                                 struct object *o = want_obj.objects[i].item;
 120                                 *p++ = buf;
 121                                 memcpy(buf, sha1_to_hex(o->sha1), 41);
 122                                 buf += 41;
 123                         }
 124                 }
 125                 if (!create_full_pack)
 126                         for (i = 0; i < have_obj.nr; i++) {
 127                                 struct object *o = have_obj.objects[i].item;
 128                                 *p++ = buf;
 129                                 *buf++ = '^';
 130                                 memcpy(buf, sha1_to_hex(o->sha1), 41);
 131                                 buf += 41;
 132                         }
 133                 *p++ = NULL;
 134                 execv_git_cmd(argv);
 135                 die("git-upload-pack: unable to exec git-rev-list");
 136         }
 137
 138         if (pipe(pu_pipe) < 0)
 139                 die("git-upload-pack: unable to create pipe");
 140         if (pipe(pe_pipe) < 0)
 141                 die("git-upload-pack: unable to create pipe");
 142         pid_pack_objects = fork();
 143         if (pid_pack_objects < 0) {
 144                 /* daemon sets things up to ignore TERM */
 145                 kill(pid_rev_list, SIGKILL);
 146                 die("git-upload-pack: unable to fork git-pack-objects");
 147         }
 148         if (!pid_pack_objects) {
 149                 dup2(lp_pipe[0], 0);
 150                 dup2(pu_pipe[1], 1);
 151                 dup2(pe_pipe[1], 2);
 152
 153                 close(lp_pipe[0]);
 154                 close(lp_pipe[1]);
 155                 close(pu_pipe[0]);
 156                 close(pu_pipe[1]);
 157                 close(pe_pipe[0]);
 158                 close(pe_pipe[1]);
 159                 execl_git_cmd("pack-objects", "--stdout", "--progress", NULL);
 160                 kill(pid_rev_list, SIGKILL);
 161                 die("git-upload-pack: unable to exec git-pack-objects");
 162         }
 163
 164         close(lp_pipe[0]);
 165         close(lp_pipe[1]);
 166
 167         /* We read from pe_pipe[0] to capture stderr output for
 168          * progress bar, and pu_pipe[0] to capture the pack data.
 169          */
 170         close(pe_pipe[1]);
 171         close(pu_pipe[1]);
 172
 173         while (1) {
 174                 const char *who;
 175                 struct pollfd pfd[2];
 176                 pid_t pid;
 177                 int status;
 178                 ssize_t sz;
 179                 int pe, pu, pollsize;
 180
 181                 pollsize = 0;
 182                 pe = pu = -1;
 183
 184                 if (0 <= pu_pipe[0]) {
 185                         pfd[pollsize].fd = pu_pipe[0];
 186                         pfd[pollsize].events = POLLIN;
 187                         pu = pollsize;
 188                         pollsize++;
 189                 }
 190                 if (0 <= pe_pipe[0]) {
 191                         pfd[pollsize].fd = pe_pipe[0];
 192                         pfd[pollsize].events = POLLIN;
 193                         pe = pollsize;
 194                         pollsize++;
 195                 }
 196
 197                 if (pollsize) {
 198                         if (poll(pfd, pollsize, -1) < 0) {
 199                                 if (errno != EINTR) {
 200                                         error("poll failed, resuming: %s",
 201                                               strerror(errno));
 202                                         sleep(1);
 203                                 }
 204                                 continue;
 205                         }
 206                         if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 207                                 /* Data ready; we keep the last byte
 208                                  * to ourselves in case we detect
 209                                  * broken rev-list, so that we can
 210                                  * leave the stream corrupted.  This
 211                                  * is unfortunate -- unpack-objects
 212                                  * would happily accept a valid pack
 213                                  * data with trailing garbage, so
 214                                  * appending garbage after we pass all
 215                                  * the pack data is not good enough to
 216                                  * signal breakage to downstream.
 217                                  */
 218                                 char *cp = data;
 219                                 ssize_t outsz = 0;
 220                                 if (0 <= buffered) {
 221                                         *cp++ = buffered;
 222                                         outsz++;
 223                                 }
 224                                 sz = read(pu_pipe[0], cp,
 225                                           sizeof(data) - outsz);
 226                                 if (0 < sz)
 227                                                 ;
 228                                 else if (sz == 0) {
 229                                         close(pu_pipe[0]);
 230                                         pu_pipe[0] = -1;
 231                                 }
 232                                 else
 233                                         goto fail;
 234                                 sz += outsz;
 235                                 if (1 < sz) {
 236                                         buffered = data[sz-1] & 0xFF;
 237                                         sz--;
 238                                 }
 239                                 else
 240                                         buffered = -1;
 241                                 sz = send_client_data(1, data, sz);
 242                                 if (sz < 0)
 243                                         goto fail;
 244                         }
 245                         if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 246                                 /* Status ready; we ship that in the side-band
 247                                  * or dump to the standard error.
 248                                  */
 249                                 sz = read(pe_pipe[0], progress,
 250                                           sizeof(progress));
 251                                 if (0 < sz)
 252                                         send_client_data(2, progress, sz);
 253                                 else if (sz == 0) {
 254                                         close(pe_pipe[0]);
 255                                         pe_pipe[0] = -1;
 256                                 }
 257                                 else
 258                                         goto fail;
 259                         }
 260                 }
 261
 262                 /* See if the children are still there */
 263                 if (pid_rev_list || pid_pack_objects) {
 264                         pid = waitpid(-1, &status, WNOHANG);
 265                         if (!pid)
 266                                 continue;
 267                         who = ((pid == pid_rev_list) ? "git-rev-list" :
 268                                (pid == pid_pack_objects) ? "git-pack-objects" :
 269                                NULL);
 270                         if (!who) {
 271                                 if (pid < 0) {
 272                                         error("git-upload-pack: %s",
 273                                               strerror(errno));
 274                                         goto fail;
 275                                 }
 276                                 error("git-upload-pack: we weren't "
 277                                       "waiting for %d", pid);
 278                                 continue;
 279                         }
 280                         if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
 281                                 error("git-upload-pack: %s died with error.",
 282                                       who);
 283                                 goto fail;
 284                         }
 285                         if (pid == pid_rev_list)
 286                                 pid_rev_list = 0;
 287                         if (pid == pid_pack_objects)
 288                                 pid_pack_objects = 0;
 289                         if (pid_rev_list || pid_pack_objects)
 290                                 continue;
 291                 }
 292
 293                 /* both died happily */
 294                 if (pollsize)
 295                         continue;
 296
 297                 /* flush the data */
 298                 if (0 <= buffered) {
 299                         data[0] = buffered;
 300                         sz = send_client_data(1, data, 1);
 301                         if (sz < 0)
 302                                 goto fail;
 303                         fprintf(stderr, "flushed.\n");
 304                 }
 305                 send_client_data(1, NULL, 0);
 306                 return;
 307         }
 308  fail:
 309         if (pid_pack_objects)
 310                 kill(pid_pack_objects, SIGKILL);
 311         if (pid_rev_list)
 312                 kill(pid_rev_list, SIGKILL);
 313         send_client_data(3, abort_msg, sizeof(abort_msg));
 314         die("git-upload-pack: %s", abort_msg);
 315 }
 316
 317 static int got_sha1(char *hex, unsigned char *sha1)
 318 {
 319         struct object *o;
 320
 321         if (get_sha1_hex(hex, sha1))
 322                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 323         if (!has_sha1_file(sha1))
 324                 return 0;
 325
 326         o = lookup_object(sha1);
 327         if (!(o && o->parsed))
 328                 o = parse_object(sha1);
 329         if (!o)
 330                 die("oops (%s)", sha1_to_hex(sha1));
 331         if (o->type == TYPE_COMMIT) {
 332                 struct commit_list *parents;
 333                 if (o->flags & THEY_HAVE)
 334                         return 0;
 335                 o->flags |= THEY_HAVE;
 336                 for (parents = ((struct commit*)o)->parents;
 337                      parents;
 338                      parents = parents->next)
 339                         parents->item->object.flags |= THEY_HAVE;
 340         }
 341         add_object_array(o, NULL, &have_obj);
 342         return 1;
 343 }
 344
 345 static int get_common_commits(void)
 346 {
 347         static char line[1000];
 348         unsigned char sha1[20], last_sha1[20];
 349         int len;
 350
 351         track_object_refs = 0;
 352         save_commit_buffer = 0;
 353
 354         for(;;) {
 355                 len = packet_read_line(0, line, sizeof(line));
 356                 reset_timeout();
 357
 358                 if (!len) {
 359                         if (have_obj.nr == 0 || multi_ack)
 360                                 packet_write(1, "NAK\n");
 361                         continue;
 362                 }
 363                 len = strip(line, len);
 364                 if (!strncmp(line, "have ", 5)) {
 365                         if (got_sha1(line+5, sha1) &&
 366                             (multi_ack || have_obj.nr == 1)) {
 367                                 packet_write(1, "ACK %s%s\n",
 368                                              sha1_to_hex(sha1),
 369                                              multi_ack ?  " continue" : "");
 370                                 if (multi_ack)
 371                                         memcpy(last_sha1, sha1, 20);
 372                         }
 373                         continue;
 374                 }
 375                 if (!strcmp(line, "done")) {
 376                         if (have_obj.nr > 0) {
 377                                 if (multi_ack)
 378                                         packet_write(1, "ACK %s\n",
 379                                                         sha1_to_hex(last_sha1));
 380                                 return 0;
 381                         }
 382                         packet_write(1, "NAK\n");
 383                         return -1;
 384                 }
 385                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 386         }
 387 }
 388
 389 static void receive_needs(void)
 390 {
 391         static char line[1000];
 392         int len;
 393
 394         for (;;) {
 395                 struct object *o;
 396                 unsigned char sha1_buf[20];
 397                 len = packet_read_line(0, line, sizeof(line));
 398                 reset_timeout();
 399                 if (!len)
 400                         return;
 401
 402                 if (strncmp("want ", line, 5) ||
 403                     get_sha1_hex(line+5, sha1_buf))
 404                         die("git-upload-pack: protocol error, "
 405                             "expected to get sha, not '%s'", line);
 406                 if (strstr(line+45, "multi_ack"))
 407                         multi_ack = 1;
 408                 if (strstr(line+45, "thin-pack"))
 409                         use_thin_pack = 1;
 410                 if (strstr(line+45, "side-band"))
 411                         use_sideband = 1;
 412
 413                 /* We have sent all our refs already, and the other end
 414                  * should have chosen out of them; otherwise they are
 415                  * asking for nonsense.
 416                  *
 417                  * Hmph.  We may later want to allow "want" line that
 418                  * asks for something like "master~10" (symbolic)...
 419                  * would it make sense?  I don't know.
 420                  */
 421                 o = lookup_object(sha1_buf);
 422                 if (!o || !(o->flags & OUR_REF))
 423                         die("git-upload-pack: not our ref %s", line+5);
 424                 if (!(o->flags & WANTED)) {
 425                         o->flags |= WANTED;
 426                         add_object_array(o, NULL, &want_obj);
 427                 }
 428         }
 429 }
 430
 431 static int send_ref(const char *refname, const unsigned char *sha1)
 432 {
 433         static const char *capabilities = "multi_ack thin-pack side-band";
 434         struct object *o = parse_object(sha1);
 435
 436         if (!o)
 437                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 438
 439         if (capabilities)
 440                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 441                         0, capabilities);
 442         else
 443                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 444         capabilities = NULL;
 445         if (!(o->flags & OUR_REF)) {
 446                 o->flags |= OUR_REF;
 447                 nr_our_refs++;
 448         }
 449         if (o->type == TYPE_TAG) {
 450                 o = deref_tag(o, refname, 0);
 451                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 452         }
 453         return 0;
 454 }
 455
 456 static int upload_pack(void)
 457 {
 458         reset_timeout();
 459         head_ref(send_ref);
 460         for_each_ref(send_ref);
 461         packet_flush(1);
 462         receive_needs();
 463         if (!want_obj.nr)
 464                 return 0;
 465         get_common_commits();
 466         create_pack_file();
 467         return 0;
 468 }
 469
 470 int main(int argc, char **argv)
 471 {
 472         char *dir;
 473         int i;
 474         int strict = 0;
 475
 476         for (i = 1; i < argc; i++) {
 477                 char *arg = argv[i];
 478
 479                 if (arg[0] != '-')
 480                         break;
 481                 if (!strcmp(arg, "--strict")) {
 482                         strict = 1;
 483                         continue;
 484                 }
 485                 if (!strncmp(arg, "--timeout=", 10)) {
 486                         timeout = atoi(arg+10);
 487                         continue;
 488                 }
 489                 if (!strcmp(arg, "--")) {
 490                         i++;
 491                         break;
 492                 }
 493         }
 494
 495         if (i != argc-1)
 496                 usage(upload_pack_usage);
 497         dir = argv[i];
 498
 499         if (!enter_repo(dir, strict))
 500                 die("'%s': unable to chdir or not a git archive", dir);
 501
 502         upload_pack();
 503         return 0;
 504 }