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