upload-pack.con commit commit walkers: setup_ident() to record correct committer in ref-log. (19c4588)
   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
  12static 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#define MAX_HAS 256
  18#define MAX_NEEDS 256
  19static int nr_has = 0, nr_needs = 0, multi_ack = 0, nr_our_refs = 0;
  20static int use_thin_pack = 0;
  21static unsigned char has_sha1[MAX_HAS][20];
  22static unsigned char needs_sha1[MAX_NEEDS][20];
  23static unsigned int timeout = 0;
  24static int use_sideband = 0;
  25
  26static void reset_timeout(void)
  27{
  28        alarm(timeout);
  29}
  30
  31static int strip(char *line, int len)
  32{
  33        if (len && line[len-1] == '\n')
  34                line[--len] = 0;
  35        return len;
  36}
  37
  38#define PACKET_MAX 1000
  39static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
  40{
  41        ssize_t ssz;
  42        const char *p;
  43
  44        if (!data) {
  45                if (!use_sideband)
  46                        return 0;
  47                packet_flush(1);
  48        }
  49
  50        if (!use_sideband) {
  51                if (fd == 3)
  52                        /* emergency quit */
  53                        fd = 2;
  54                if (fd == 2) {
  55                        xwrite(fd, data, sz);
  56                        return sz;
  57                }
  58                return safe_write(fd, data, sz);
  59        }
  60        p = data;
  61        ssz = sz;
  62        while (sz) {
  63                unsigned n;
  64                char hdr[5];
  65
  66                n = sz;
  67                if (PACKET_MAX - 5 < n)
  68                        n = PACKET_MAX - 5;
  69                sprintf(hdr, "%04x", n + 5);
  70                hdr[4] = fd;
  71                safe_write(1, hdr, 5);
  72                safe_write(1, p, n);
  73                p += n;
  74                sz -= n;
  75        }
  76        return ssz;
  77}
  78
  79static void create_pack_file(void)
  80{
  81        /* Pipes between rev-list to pack-objects, pack-objects to us
  82         * and pack-objects error stream for progress bar.
  83         */
  84        int lp_pipe[2], pu_pipe[2], pe_pipe[2];
  85        pid_t pid_rev_list, pid_pack_objects;
  86        int create_full_pack = (nr_our_refs == nr_needs && !nr_has);
  87        char data[8193], progress[128];
  88        char abort_msg[] = "aborting due to possible repository "
  89                "corruption on the remote side.";
  90        int buffered = -1;
  91
  92        if (pipe(lp_pipe) < 0)
  93                die("git-upload-pack: unable to create pipe");
  94        pid_rev_list = fork();
  95        if (pid_rev_list < 0)
  96                die("git-upload-pack: unable to fork git-rev-list");
  97
  98        if (!pid_rev_list) {
  99                int i;
 100                int args;
 101                const char **argv;
 102                const char **p;
 103                char *buf;
 104
 105                if (create_full_pack) {
 106                        args = 10;
 107                        use_thin_pack = 0; /* no point doing it */
 108                }
 109                else
 110                        args = nr_has + nr_needs + 5;
 111                p = xmalloc(args * sizeof(char *));
 112                argv = (const char **) p;
 113                buf = xmalloc(args * 45);
 114
 115                dup2(lp_pipe[1], 1);
 116                close(0);
 117                close(lp_pipe[0]);
 118                close(lp_pipe[1]);
 119                *p++ = "rev-list";
 120                *p++ = use_thin_pack ? "--objects-edge" : "--objects";
 121                if (create_full_pack || MAX_NEEDS <= nr_needs)
 122                        *p++ = "--all";
 123                else {
 124                        for (i = 0; i < nr_needs; i++) {
 125                                *p++ = buf;
 126                                memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
 127                                buf += 41;
 128                        }
 129                }
 130                if (!create_full_pack)
 131                        for (i = 0; i < nr_has; i++) {
 132                                *p++ = buf;
 133                                *buf++ = '^';
 134                                memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
 135                                buf += 41;
 136                        }
 137                *p++ = NULL;
 138                execv_git_cmd(argv);
 139                die("git-upload-pack: unable to exec git-rev-list");
 140        }
 141
 142        if (pipe(pu_pipe) < 0)
 143                die("git-upload-pack: unable to create pipe");
 144        if (pipe(pe_pipe) < 0)
 145                die("git-upload-pack: unable to create pipe");
 146        pid_pack_objects = fork();
 147        if (pid_pack_objects < 0) {
 148                /* daemon sets things up to ignore TERM */
 149                kill(pid_rev_list, SIGKILL);
 150                die("git-upload-pack: unable to fork git-pack-objects");
 151        }
 152        if (!pid_pack_objects) {
 153                dup2(lp_pipe[0], 0);
 154                dup2(pu_pipe[1], 1);
 155                dup2(pe_pipe[1], 2);
 156
 157                close(lp_pipe[0]);
 158                close(lp_pipe[1]);
 159                close(pu_pipe[0]);
 160                close(pu_pipe[1]);
 161                close(pe_pipe[0]);
 162                close(pe_pipe[1]);
 163                execl_git_cmd("pack-objects", "--stdout", "--progress", NULL);
 164                kill(pid_rev_list, SIGKILL);
 165                die("git-upload-pack: unable to exec git-pack-objects");
 166        }
 167
 168        close(lp_pipe[0]);
 169        close(lp_pipe[1]);
 170
 171        /* We read from pe_pipe[0] to capture stderr output for
 172         * progress bar, and pu_pipe[0] to capture the pack data.
 173         */
 174        close(pe_pipe[1]);
 175        close(pu_pipe[1]);
 176
 177        while (1) {
 178                const char *who;
 179                struct pollfd pfd[2];
 180                pid_t pid;
 181                int status;
 182                ssize_t sz;
 183                int pe, pu, pollsize;
 184
 185                reset_timeout();
 186
 187                pollsize = 0;
 188                pe = pu = -1;
 189
 190                if (0 <= pu_pipe[0]) {
 191                        pfd[pollsize].fd = pu_pipe[0];
 192                        pfd[pollsize].events = POLLIN;
 193                        pu = pollsize;
 194                        pollsize++;
 195                }
 196                if (0 <= pe_pipe[0]) {
 197                        pfd[pollsize].fd = pe_pipe[0];
 198                        pfd[pollsize].events = POLLIN;
 199                        pe = pollsize;
 200                        pollsize++;
 201                }
 202
 203                if (pollsize) {
 204                        if (poll(pfd, pollsize, -1) < 0) {
 205                                if (errno != EINTR) {
 206                                        error("poll failed, resuming: %s",
 207                                              strerror(errno));
 208                                        sleep(1);
 209                                }
 210                                continue;
 211                        }
 212                        if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 213                                /* Data ready; we keep the last byte
 214                                 * to ourselves in case we detect
 215                                 * broken rev-list, so that we can
 216                                 * leave the stream corrupted.  This
 217                                 * is unfortunate -- unpack-objects
 218                                 * would happily accept a valid pack
 219                                 * data with trailing garbage, so
 220                                 * appending garbage after we pass all
 221                                 * the pack data is not good enough to
 222                                 * signal breakage to downstream.
 223                                 */
 224                                char *cp = data;
 225                                ssize_t outsz = 0;
 226                                if (0 <= buffered) {
 227                                        *cp++ = buffered;
 228                                        outsz++;
 229                                }
 230                                sz = read(pu_pipe[0], cp,
 231                                          sizeof(data) - outsz);
 232                                if (0 < sz)
 233                                                ;
 234                                else if (sz == 0) {
 235                                        close(pu_pipe[0]);
 236                                        pu_pipe[0] = -1;
 237                                }
 238                                else
 239                                        goto fail;
 240                                sz += outsz;
 241                                if (1 < sz) {
 242                                        buffered = data[sz-1] & 0xFF;
 243                                        sz--;
 244                                }
 245                                else
 246                                        buffered = -1;
 247                                sz = send_client_data(1, data, sz);
 248                                if (sz < 0)
 249                                        goto fail;
 250                        }
 251                        if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 252                                /* Status ready; we ship that in the side-band
 253                                 * or dump to the standard error.
 254                                 */
 255                                sz = read(pe_pipe[0], progress,
 256                                          sizeof(progress));
 257                                if (0 < sz)
 258                                        send_client_data(2, progress, sz);
 259                                else if (sz == 0) {
 260                                        close(pe_pipe[0]);
 261                                        pe_pipe[0] = -1;
 262                                }
 263                                else
 264                                        goto fail;
 265                        }
 266                }
 267
 268                /* See if the children are still there */
 269                if (pid_rev_list || pid_pack_objects) {
 270                        pid = waitpid(-1, &status, WNOHANG);
 271                        if (!pid)
 272                                continue;
 273                        who = ((pid == pid_rev_list) ? "git-rev-list" :
 274                               (pid == pid_pack_objects) ? "git-pack-objects" :
 275                               NULL);
 276                        if (!who) {
 277                                if (pid < 0) {
 278                                        error("git-upload-pack: %s",
 279                                              strerror(errno));
 280                                        goto fail;
 281                                }
 282                                error("git-upload-pack: we weren't "
 283                                      "waiting for %d", pid);
 284                                continue;
 285                        }
 286                        if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
 287                                error("git-upload-pack: %s died with error.",
 288                                      who);
 289                                goto fail;
 290                        }
 291                        if (pid == pid_rev_list)
 292                                pid_rev_list = 0;
 293                        if (pid == pid_pack_objects)
 294                                pid_pack_objects = 0;
 295                        if (pid_rev_list || pid_pack_objects)
 296                                continue;
 297                }
 298
 299                /* both died happily */
 300                if (pollsize)
 301                        continue;
 302
 303                /* flush the data */
 304                if (0 <= buffered) {
 305                        data[0] = buffered;
 306                        sz = send_client_data(1, data, 1);
 307                        if (sz < 0)
 308                                goto fail;
 309                        fprintf(stderr, "flushed.\n");
 310                }
 311                send_client_data(1, NULL, 0);
 312                return;
 313        }
 314 fail:
 315        if (pid_pack_objects)
 316                kill(pid_pack_objects, SIGKILL);
 317        if (pid_rev_list)
 318                kill(pid_rev_list, SIGKILL);
 319        send_client_data(3, abort_msg, sizeof(abort_msg));
 320        die("git-upload-pack: %s", abort_msg);
 321}
 322
 323static int got_sha1(char *hex, unsigned char *sha1)
 324{
 325        if (get_sha1_hex(hex, sha1))
 326                die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 327        if (!has_sha1_file(sha1))
 328                return 0;
 329        if (nr_has < MAX_HAS) {
 330                struct object *o = lookup_object(sha1);
 331                if (!(o && o->parsed))
 332                        o = parse_object(sha1);
 333                if (!o)
 334                        die("oops (%s)", sha1_to_hex(sha1));
 335                if (o->type == OBJ_COMMIT) {
 336                        struct commit_list *parents;
 337                        if (o->flags & THEY_HAVE)
 338                                return 0;
 339                        o->flags |= THEY_HAVE;
 340                        for (parents = ((struct commit*)o)->parents;
 341                             parents;
 342                             parents = parents->next)
 343                                parents->item->object.flags |= THEY_HAVE;
 344                }
 345                memcpy(has_sha1[nr_has++], sha1, 20);
 346        }
 347        return 1;
 348}
 349
 350static int get_common_commits(void)
 351{
 352        static char line[1000];
 353        unsigned char sha1[20], last_sha1[20];
 354        int len;
 355
 356        track_object_refs = 0;
 357        save_commit_buffer = 0;
 358
 359        for(;;) {
 360                len = packet_read_line(0, line, sizeof(line));
 361                reset_timeout();
 362
 363                if (!len) {
 364                        if (nr_has == 0 || multi_ack)
 365                                packet_write(1, "NAK\n");
 366                        continue;
 367                }
 368                len = strip(line, len);
 369                if (!strncmp(line, "have ", 5)) {
 370                        if (got_sha1(line+5, sha1) &&
 371                                        (multi_ack || nr_has == 1)) {
 372                                if (nr_has >= MAX_HAS)
 373                                        multi_ack = 0;
 374                                packet_write(1, "ACK %s%s\n",
 375                                        sha1_to_hex(sha1),
 376                                        multi_ack ?  " continue" : "");
 377                                if (multi_ack)
 378                                        memcpy(last_sha1, sha1, 20);
 379                        }
 380                        continue;
 381                }
 382                if (!strcmp(line, "done")) {
 383                        if (nr_has > 0) {
 384                                if (multi_ack)
 385                                        packet_write(1, "ACK %s\n",
 386                                                        sha1_to_hex(last_sha1));
 387                                return 0;
 388                        }
 389                        packet_write(1, "NAK\n");
 390                        return -1;
 391                }
 392                die("git-upload-pack: expected SHA1 list, got '%s'", line);
 393        }
 394}
 395
 396static int receive_needs(void)
 397{
 398        static char line[1000];
 399        int len, needs;
 400
 401        needs = 0;
 402        for (;;) {
 403                struct object *o;
 404                unsigned char dummy[20], *sha1_buf;
 405                len = packet_read_line(0, line, sizeof(line));
 406                reset_timeout();
 407                if (!len)
 408                        return needs;
 409
 410                sha1_buf = dummy;
 411                if (needs == MAX_NEEDS) {
 412                        fprintf(stderr,
 413                                "warning: supporting only a max of %d requests. "
 414                                "sending everything instead.\n",
 415                                MAX_NEEDS);
 416                }
 417                else if (needs < MAX_NEEDS)
 418                        sha1_buf = needs_sha1[needs];
 419
 420                if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
 421                        die("git-upload-pack: protocol error, "
 422                            "expected to get sha, not '%s'", line);
 423                if (strstr(line+45, "multi_ack"))
 424                        multi_ack = 1;
 425                if (strstr(line+45, "thin-pack"))
 426                        use_thin_pack = 1;
 427                if (strstr(line+45, "side-band"))
 428                        use_sideband = 1;
 429
 430                /* We have sent all our refs already, and the other end
 431                 * should have chosen out of them; otherwise they are
 432                 * asking for nonsense.
 433                 *
 434                 * Hmph.  We may later want to allow "want" line that
 435                 * asks for something like "master~10" (symbolic)...
 436                 * would it make sense?  I don't know.
 437                 */
 438                o = lookup_object(sha1_buf);
 439                if (!o || !(o->flags & OUR_REF))
 440                        die("git-upload-pack: not our ref %s", line+5);
 441                if (!(o->flags & WANTED)) {
 442                        o->flags |= WANTED;
 443                        needs++;
 444                }
 445        }
 446}
 447
 448static int send_ref(const char *refname, const unsigned char *sha1)
 449{
 450        static const char *capabilities = "multi_ack thin-pack side-band";
 451        struct object *o = parse_object(sha1);
 452
 453        if (!o)
 454                die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 455
 456        if (capabilities)
 457                packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 458                        0, capabilities);
 459        else
 460                packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 461        capabilities = NULL;
 462        if (!(o->flags & OUR_REF)) {
 463                o->flags |= OUR_REF;
 464                nr_our_refs++;
 465        }
 466        if (o->type == OBJ_TAG) {
 467                o = deref_tag(o, refname, 0);
 468                packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 469        }
 470        return 0;
 471}
 472
 473static int upload_pack(void)
 474{
 475        reset_timeout();
 476        head_ref(send_ref);
 477        for_each_ref(send_ref);
 478        packet_flush(1);
 479        nr_needs = receive_needs();
 480        if (!nr_needs)
 481                return 0;
 482        get_common_commits();
 483        create_pack_file();
 484        return 0;
 485}
 486
 487int main(int argc, char **argv)
 488{
 489        char *dir;
 490        int i;
 491        int strict = 0;
 492
 493        for (i = 1; i < argc; i++) {
 494                char *arg = argv[i];
 495
 496                if (arg[0] != '-')
 497                        break;
 498                if (!strcmp(arg, "--strict")) {
 499                        strict = 1;
 500                        continue;
 501                }
 502                if (!strncmp(arg, "--timeout=", 10)) {
 503                        timeout = atoi(arg+10);
 504                        continue;
 505                }
 506                if (!strcmp(arg, "--")) {
 507                        i++;
 508                        break;
 509                }
 510        }
 511        
 512        if (i != argc-1)
 513                usage(upload_pack_usage);
 514        dir = argv[i];
 515
 516        if (!enter_repo(dir, strict))
 517                die("'%s': unable to chdir or not a git archive", dir);
 518
 519        upload_pack();
 520        return 0;
 521}