upload-pack.con commit Merge branch 'gl/cleanup' (a7f0519)
   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)
  17static int multi_ack, nr_our_refs;
  18static int use_thin_pack;
  19static struct object_array have_obj;
  20static struct object_array want_obj;
  21static unsigned int timeout;
  22static int use_sideband;
  23
  24static void reset_timeout(void)
  25{
  26        alarm(timeout);
  27}
  28
  29static 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
  37static 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                if (fd == 2) {
  53                        xwrite(fd, data, sz);
  54                        return sz;
  55                }
  56                return safe_write(fd, data, sz);
  57        }
  58        p = data;
  59        ssz = sz;
  60        while (sz) {
  61                unsigned n;
  62                char hdr[5];
  63
  64                n = sz;
  65                if (PACKET_MAX - 5 < n)
  66                        n = PACKET_MAX - 5;
  67                sprintf(hdr, "%04x", n + 5);
  68                hdr[4] = fd;
  69                safe_write(1, hdr, 5);
  70                safe_write(1, p, n);
  71                p += n;
  72                sz -= n;
  73        }
  74        return ssz;
  75}
  76
  77static void create_pack_file(void)
  78{
  79        /* Pipes between rev-list to pack-objects, pack-objects to us
  80         * and pack-objects error stream for progress bar.
  81         */
  82        int lp_pipe[2], pu_pipe[2], pe_pipe[2];
  83        pid_t pid_rev_list, pid_pack_objects;
  84        int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
  85        char data[8193], progress[128];
  86        char abort_msg[] = "aborting due to possible repository "
  87                "corruption on the remote side.";
  88        int buffered = -1;
  89
  90        if (pipe(lp_pipe) < 0)
  91                die("git-upload-pack: unable to create pipe");
  92        pid_rev_list = fork();
  93        if (pid_rev_list < 0)
  94                die("git-upload-pack: unable to fork git-rev-list");
  95
  96        if (!pid_rev_list) {
  97                int i;
  98                int args;
  99                const char **argv;
 100                const char **p;
 101                char *buf;
 102
 103                if (create_full_pack) {
 104                        args = 10;
 105                        use_thin_pack = 0; /* no point doing it */
 106                }
 107                else
 108                        args = have_obj.nr + want_obj.nr + 5;
 109                p = xmalloc(args * sizeof(char *));
 110                argv = (const char **) p;
 111                buf = xmalloc(args * 45);
 112
 113                dup2(lp_pipe[1], 1);
 114                close(0);
 115                close(lp_pipe[0]);
 116                close(lp_pipe[1]);
 117                *p++ = "rev-list";
 118                *p++ = use_thin_pack ? "--objects-edge" : "--objects";
 119                if (create_full_pack)
 120                        *p++ = "--all";
 121                else {
 122                        for (i = 0; i < want_obj.nr; i++) {
 123                                struct object *o = want_obj.objects[i].item;
 124                                *p++ = buf;
 125                                memcpy(buf, sha1_to_hex(o->sha1), 41);
 126                                buf += 41;
 127                        }
 128                }
 129                if (!create_full_pack)
 130                        for (i = 0; i < have_obj.nr; i++) {
 131                                struct object *o = have_obj.objects[i].item;
 132                                *p++ = buf;
 133                                *buf++ = '^';
 134                                memcpy(buf, sha1_to_hex(o->sha1), 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        struct object *o;
 326
 327        if (get_sha1_hex(hex, sha1))
 328                die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 329        if (!has_sha1_file(sha1))
 330                return 0;
 331
 332        o = lookup_object(sha1);
 333        if (!(o && o->parsed))
 334                o = parse_object(sha1);
 335        if (!o)
 336                die("oops (%s)", sha1_to_hex(sha1));
 337        if (o->type == OBJ_COMMIT) {
 338                struct commit_list *parents;
 339                if (o->flags & THEY_HAVE)
 340                        return 0;
 341                o->flags |= THEY_HAVE;
 342                for (parents = ((struct commit*)o)->parents;
 343                     parents;
 344                     parents = parents->next)
 345                        parents->item->object.flags |= THEY_HAVE;
 346        }
 347        add_object_array(o, NULL, &have_obj);
 348        return 1;
 349}
 350
 351static int get_common_commits(void)
 352{
 353        static char line[1000];
 354        unsigned char sha1[20], last_sha1[20];
 355        int len;
 356
 357        track_object_refs = 0;
 358        save_commit_buffer = 0;
 359
 360        for(;;) {
 361                len = packet_read_line(0, line, sizeof(line));
 362                reset_timeout();
 363
 364                if (!len) {
 365                        if (have_obj.nr == 0 || multi_ack)
 366                                packet_write(1, "NAK\n");
 367                        continue;
 368                }
 369                len = strip(line, len);
 370                if (!strncmp(line, "have ", 5)) {
 371                        if (got_sha1(line+5, sha1) &&
 372                            (multi_ack || have_obj.nr == 1)) {
 373                                packet_write(1, "ACK %s%s\n",
 374                                             sha1_to_hex(sha1),
 375                                             multi_ack ?  " continue" : "");
 376                                if (multi_ack)
 377                                        hashcpy(last_sha1, sha1);
 378                        }
 379                        continue;
 380                }
 381                if (!strcmp(line, "done")) {
 382                        if (have_obj.nr > 0) {
 383                                if (multi_ack)
 384                                        packet_write(1, "ACK %s\n",
 385                                                        sha1_to_hex(last_sha1));
 386                                return 0;
 387                        }
 388                        packet_write(1, "NAK\n");
 389                        return -1;
 390                }
 391                die("git-upload-pack: expected SHA1 list, got '%s'", line);
 392        }
 393}
 394
 395static void receive_needs(void)
 396{
 397        static char line[1000];
 398        int len;
 399
 400        for (;;) {
 401                struct object *o;
 402                unsigned char sha1_buf[20];
 403                len = packet_read_line(0, line, sizeof(line));
 404                reset_timeout();
 405                if (!len)
 406                        return;
 407
 408                if (strncmp("want ", line, 5) ||
 409                    get_sha1_hex(line+5, sha1_buf))
 410                        die("git-upload-pack: protocol error, "
 411                            "expected to get sha, not '%s'", line);
 412                if (strstr(line+45, "multi_ack"))
 413                        multi_ack = 1;
 414                if (strstr(line+45, "thin-pack"))
 415                        use_thin_pack = 1;
 416                if (strstr(line+45, "side-band"))
 417                        use_sideband = 1;
 418
 419                /* We have sent all our refs already, and the other end
 420                 * should have chosen out of them; otherwise they are
 421                 * asking for nonsense.
 422                 *
 423                 * Hmph.  We may later want to allow "want" line that
 424                 * asks for something like "master~10" (symbolic)...
 425                 * would it make sense?  I don't know.
 426                 */
 427                o = lookup_object(sha1_buf);
 428                if (!o || !(o->flags & OUR_REF))
 429                        die("git-upload-pack: not our ref %s", line+5);
 430                if (!(o->flags & WANTED)) {
 431                        o->flags |= WANTED;
 432                        add_object_array(o, NULL, &want_obj);
 433                }
 434        }
 435}
 436
 437static int send_ref(const char *refname, const unsigned char *sha1)
 438{
 439        static const char *capabilities = "multi_ack thin-pack side-band";
 440        struct object *o = parse_object(sha1);
 441
 442        if (!o)
 443                die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 444
 445        if (capabilities)
 446                packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 447                        0, capabilities);
 448        else
 449                packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 450        capabilities = NULL;
 451        if (!(o->flags & OUR_REF)) {
 452                o->flags |= OUR_REF;
 453                nr_our_refs++;
 454        }
 455        if (o->type == OBJ_TAG) {
 456                o = deref_tag(o, refname, 0);
 457                packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 458        }
 459        return 0;
 460}
 461
 462static void upload_pack(void)
 463{
 464        reset_timeout();
 465        head_ref(send_ref);
 466        for_each_ref(send_ref);
 467        packet_flush(1);
 468        receive_needs();
 469        if (want_obj.nr) {
 470                get_common_commits();
 471                create_pack_file();
 472        }
 473}
 474
 475int main(int argc, char **argv)
 476{
 477        char *dir;
 478        int i;
 479        int strict = 0;
 480
 481        for (i = 1; i < argc; i++) {
 482                char *arg = argv[i];
 483
 484                if (arg[0] != '-')
 485                        break;
 486                if (!strcmp(arg, "--strict")) {
 487                        strict = 1;
 488                        continue;
 489                }
 490                if (!strncmp(arg, "--timeout=", 10)) {
 491                        timeout = atoi(arg+10);
 492                        continue;
 493                }
 494                if (!strcmp(arg, "--")) {
 495                        i++;
 496                        break;
 497                }
 498        }
 499        
 500        if (i != argc-1)
 501                usage(upload_pack_usage);
 502        dir = argv[i];
 503
 504        if (!enter_repo(dir, strict))
 505                die("'%s': unable to chdir or not a git archive", dir);
 506
 507        upload_pack();
 508        return 0;
 509}