upload-pack.con commit upload-pack: prepare for sideband message support. (363b781)
   1#include "cache.h"
   2#include "refs.h"
   3#include "pkt-line.h"
   4#include "tag.h"
   5#include "object.h"
   6#include "commit.h"
   7#include "exec_cmd.h"
   8#include <signal.h>
   9#include <sys/poll.h>
  10#include <sys/wait.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;
  24
  25static void reset_timeout(void)
  26{
  27        alarm(timeout);
  28}
  29
  30static int strip(char *line, int len)
  31{
  32        if (len && line[len-1] == '\n')
  33                line[--len] = 0;
  34        return len;
  35}
  36
  37static void create_pack_file(void)
  38{
  39        /* Pipes between rev-list to pack-objects, pack-objects to us
  40         * and pack-objects error stream for progress bar.
  41         */
  42        int lp_pipe[2], pu_pipe[2], pe_pipe[2];
  43        pid_t pid_rev_list, pid_pack_objects;
  44        int create_full_pack = (nr_our_refs == nr_needs && !nr_has);
  45        char data[8193], progress[128];
  46        int buffered = -1;
  47
  48        if (pipe(lp_pipe) < 0)
  49                die("git-upload-pack: unable to create pipe");
  50        pid_rev_list = fork();
  51        if (pid_rev_list < 0)
  52                die("git-upload-pack: unable to fork git-rev-list");
  53
  54        if (!pid_rev_list) {
  55                int i;
  56                int args;
  57                const char **argv;
  58                char *buf;
  59                char **p;
  60
  61                if (create_full_pack) {
  62                        args = 10;
  63                        use_thin_pack = 0; /* no point doing it */
  64                }
  65                else
  66                        args = nr_has + nr_needs + 5;
  67                p = xmalloc(args * sizeof(char *));
  68                argv = (const char **) p;
  69                buf = xmalloc(args * 45);
  70
  71                dup2(lp_pipe[1], 1);
  72                close(0);
  73                close(lp_pipe[0]);
  74                close(lp_pipe[1]);
  75                *p++ = "rev-list";
  76                *p++ = use_thin_pack ? "--objects-edge" : "--objects";
  77                if (create_full_pack || MAX_NEEDS <= nr_needs)
  78                        *p++ = "--all";
  79                else {
  80                        for (i = 0; i < nr_needs; i++) {
  81                                *p++ = buf;
  82                                memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
  83                                buf += 41;
  84                        }
  85                }
  86                if (!create_full_pack)
  87                        for (i = 0; i < nr_has; i++) {
  88                                *p++ = buf;
  89                                *buf++ = '^';
  90                                memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
  91                                buf += 41;
  92                        }
  93                *p++ = NULL;
  94                execv_git_cmd(argv);
  95                die("git-upload-pack: unable to exec git-rev-list");
  96        }
  97
  98        if (pipe(pu_pipe) < 0)
  99                die("git-upload-pack: unable to create pipe");
 100        if (pipe(pe_pipe) < 0)
 101                die("git-upload-pack: unable to create pipe");
 102        pid_pack_objects = fork();
 103        if (pid_pack_objects < 0) {
 104                /* daemon sets things up to ignore TERM */
 105                kill(pid_rev_list, SIGKILL);
 106                die("git-upload-pack: unable to fork git-pack-objects");
 107        }
 108        if (!pid_pack_objects) {
 109                dup2(lp_pipe[0], 0);
 110                dup2(pu_pipe[1], 1);
 111                dup2(pe_pipe[1], 2);
 112
 113                close(lp_pipe[0]);
 114                close(lp_pipe[1]);
 115                close(pu_pipe[0]);
 116                close(pu_pipe[1]);
 117                close(pe_pipe[0]);
 118                close(pe_pipe[1]);
 119                execl_git_cmd("pack-objects", "--stdout", "--progress", NULL);
 120                kill(pid_rev_list, SIGKILL);
 121                die("git-upload-pack: unable to exec git-pack-objects");
 122        }
 123
 124        close(lp_pipe[0]);
 125        close(lp_pipe[1]);
 126
 127        /* We read from pe_pipe[0] to capture stderr output for
 128         * progress bar, and pu_pipe[0] to capture the pack data.
 129         */
 130        close(pe_pipe[1]);
 131        close(pu_pipe[1]);
 132
 133        while (1) {
 134                const char *who;
 135                char *cp;
 136                struct pollfd pfd[2];
 137                pid_t pid;
 138                int status;
 139                ssize_t sz;
 140                int pe, pu, pollsize;
 141
 142                pollsize = 0;
 143                pe = pu = -1;
 144
 145                if (0 <= pu_pipe[0]) {
 146                        pfd[pollsize].fd = pu_pipe[0];
 147                        pfd[pollsize].events = POLLIN;
 148                        pu = pollsize;
 149                        pollsize++;
 150                }
 151                if (0 <= pe_pipe[0]) {
 152                        pfd[pollsize].fd = pe_pipe[0];
 153                        pfd[pollsize].events = POLLIN;
 154                        pe = pollsize;
 155                        pollsize++;
 156                }
 157
 158                if (pollsize) {
 159                        if (poll(pfd, pollsize, -1) < 0) {
 160                                if (errno != EINTR) {
 161                                        error("poll failed, resuming: %s",
 162                                              strerror(errno));
 163                                        sleep(1);
 164                                }
 165                                continue;
 166                        }
 167                        if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 168                                /* Data ready; we keep the last byte
 169                                 * to ourselves in case we detect
 170                                 * broken rev-list, so that we can
 171                                 * leave the stream corrupted.  This
 172                                 * is unfortunate -- unpack-objects
 173                                 * would happily accept a valid pack
 174                                 * data with trailing garbage, so
 175                                 * appending garbage after we pass all
 176                                 * the pack data is not good enough to
 177                                 * signal breakage to downstream.
 178                                 */
 179                                char *cp = data;
 180                                ssize_t outsz = 0;
 181                                if (0 <= buffered) {
 182                                        *cp++ = buffered;
 183                                        outsz++;
 184                                }
 185                                sz = read(pu_pipe[0], cp,
 186                                          sizeof(data) - outsz);
 187                                if (0 < sz)
 188                                                ;
 189                                else if (sz == 0) {
 190                                        close(pu_pipe[0]);
 191                                        pu_pipe[0] = -1;
 192                                }
 193                                else
 194                                        goto fail;
 195                                sz += outsz;
 196                                if (1 < sz) {
 197                                        buffered = data[sz-1] & 0xFF;
 198                                        sz--;
 199                                }
 200                                else
 201                                        buffered = -1;
 202                                sz = xwrite(1, data, sz);
 203                                if (sz < 0)
 204                                        goto fail;
 205                        }
 206                        if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 207                                /* Status ready; we do not use it for now,
 208                                 * but later we will add side-band to send it
 209                                 * to the other side.
 210                                 */
 211                                sz = read(pe_pipe[0], progress,
 212                                          sizeof(progress));
 213                                if (0 < sz)
 214                                        write(2, progress, sz);
 215                                else if (sz == 0) {
 216                                        close(pe_pipe[0]);
 217                                        pe_pipe[0] = -1;
 218                                }
 219                                else
 220                                        goto fail;
 221                        }
 222                }
 223
 224                /* See if the children are still there */
 225                if (pid_rev_list || pid_pack_objects) {
 226                        pid = waitpid(-1, &status, WNOHANG);
 227                        if (!pid)
 228                                continue;
 229                        who = ((pid == pid_rev_list) ? "git-rev-list" :
 230                               (pid == pid_pack_objects) ? "git-pack-objects" :
 231                               NULL);
 232                        if (!who) {
 233                                if (pid < 0) {
 234                                        error("git-upload-pack: %s",
 235                                              strerror(errno));
 236                                        goto fail;
 237                                }
 238                                error("git-upload-pack: we weren't "
 239                                      "waiting for %d", pid);
 240                                continue;
 241                        }
 242                        if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
 243                                error("git-upload-pack: %s died with error.",
 244                                      who);
 245                                goto fail;
 246                        }
 247                        if (pid == pid_rev_list)
 248                                pid_rev_list = 0;
 249                        if (pid == pid_pack_objects)
 250                                pid_pack_objects = 0;
 251                        if (pid_rev_list || pid_pack_objects)
 252                                continue;
 253                }
 254
 255                /* both died happily */
 256                if (pollsize)
 257                        continue;
 258
 259                /* flush the data */
 260                if (0 <= buffered) {
 261                        data[0] = buffered;
 262                        sz = xwrite(1, data, 1);
 263                        if (sz < 0)
 264                                goto fail;
 265                        fprintf(stderr, "flushed.\n");
 266                }
 267                return;
 268        }
 269 fail:
 270        if (pid_pack_objects)
 271                kill(pid_pack_objects, SIGKILL);
 272        if (pid_rev_list)
 273                kill(pid_rev_list, SIGKILL);
 274        die("git-upload-pack: aborting due to possible repository corruption on the remote side.");
 275}
 276
 277static int got_sha1(char *hex, unsigned char *sha1)
 278{
 279        if (get_sha1_hex(hex, sha1))
 280                die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 281        if (!has_sha1_file(sha1))
 282                return 0;
 283        if (nr_has < MAX_HAS) {
 284                struct object *o = lookup_object(sha1);
 285                if (!(o && o->parsed))
 286                        o = parse_object(sha1);
 287                if (!o)
 288                        die("oops (%s)", sha1_to_hex(sha1));
 289                if (o->type == TYPE_COMMIT) {
 290                        struct commit_list *parents;
 291                        if (o->flags & THEY_HAVE)
 292                                return 0;
 293                        o->flags |= THEY_HAVE;
 294                        for (parents = ((struct commit*)o)->parents;
 295                             parents;
 296                             parents = parents->next)
 297                                parents->item->object.flags |= THEY_HAVE;
 298                }
 299                memcpy(has_sha1[nr_has++], sha1, 20);
 300        }
 301        return 1;
 302}
 303
 304static int get_common_commits(void)
 305{
 306        static char line[1000];
 307        unsigned char sha1[20], last_sha1[20];
 308        int len;
 309
 310        track_object_refs = 0;
 311        save_commit_buffer = 0;
 312
 313        for(;;) {
 314                len = packet_read_line(0, line, sizeof(line));
 315                reset_timeout();
 316
 317                if (!len) {
 318                        if (nr_has == 0 || multi_ack)
 319                                packet_write(1, "NAK\n");
 320                        continue;
 321                }
 322                len = strip(line, len);
 323                if (!strncmp(line, "have ", 5)) {
 324                        if (got_sha1(line+5, sha1) &&
 325                                        (multi_ack || nr_has == 1)) {
 326                                if (nr_has >= MAX_HAS)
 327                                        multi_ack = 0;
 328                                packet_write(1, "ACK %s%s\n",
 329                                        sha1_to_hex(sha1),
 330                                        multi_ack ?  " continue" : "");
 331                                if (multi_ack)
 332                                        memcpy(last_sha1, sha1, 20);
 333                        }
 334                        continue;
 335                }
 336                if (!strcmp(line, "done")) {
 337                        if (nr_has > 0) {
 338                                if (multi_ack)
 339                                        packet_write(1, "ACK %s\n",
 340                                                        sha1_to_hex(last_sha1));
 341                                return 0;
 342                        }
 343                        packet_write(1, "NAK\n");
 344                        return -1;
 345                }
 346                die("git-upload-pack: expected SHA1 list, got '%s'", line);
 347        }
 348}
 349
 350static int receive_needs(void)
 351{
 352        static char line[1000];
 353        int len, needs;
 354
 355        needs = 0;
 356        for (;;) {
 357                struct object *o;
 358                unsigned char dummy[20], *sha1_buf;
 359                len = packet_read_line(0, line, sizeof(line));
 360                reset_timeout();
 361                if (!len)
 362                        return needs;
 363
 364                sha1_buf = dummy;
 365                if (needs == MAX_NEEDS) {
 366                        fprintf(stderr,
 367                                "warning: supporting only a max of %d requests. "
 368                                "sending everything instead.\n",
 369                                MAX_NEEDS);
 370                }
 371                else if (needs < MAX_NEEDS)
 372                        sha1_buf = needs_sha1[needs];
 373
 374                if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
 375                        die("git-upload-pack: protocol error, "
 376                            "expected to get sha, not '%s'", line);
 377                if (strstr(line+45, "multi_ack"))
 378                        multi_ack = 1;
 379                if (strstr(line+45, "thin-pack"))
 380                        use_thin_pack = 1;
 381
 382                /* We have sent all our refs already, and the other end
 383                 * should have chosen out of them; otherwise they are
 384                 * asking for nonsense.
 385                 *
 386                 * Hmph.  We may later want to allow "want" line that
 387                 * asks for something like "master~10" (symbolic)...
 388                 * would it make sense?  I don't know.
 389                 */
 390                o = lookup_object(sha1_buf);
 391                if (!o || !(o->flags & OUR_REF))
 392                        die("git-upload-pack: not our ref %s", line+5);
 393                if (!(o->flags & WANTED)) {
 394                        o->flags |= WANTED;
 395                        needs++;
 396                }
 397        }
 398}
 399
 400static int send_ref(const char *refname, const unsigned char *sha1)
 401{
 402        static char *capabilities = "multi_ack thin-pack";
 403        struct object *o = parse_object(sha1);
 404
 405        if (!o)
 406                die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 407
 408        if (capabilities)
 409                packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 410                        0, capabilities);
 411        else
 412                packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 413        capabilities = NULL;
 414        if (!(o->flags & OUR_REF)) {
 415                o->flags |= OUR_REF;
 416                nr_our_refs++;
 417        }
 418        if (o->type == TYPE_TAG) {
 419                o = deref_tag(o, refname, 0);
 420                packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 421        }
 422        return 0;
 423}
 424
 425static int upload_pack(void)
 426{
 427        reset_timeout();
 428        head_ref(send_ref);
 429        for_each_ref(send_ref);
 430        packet_flush(1);
 431        nr_needs = receive_needs();
 432        if (!nr_needs)
 433                return 0;
 434        get_common_commits();
 435        create_pack_file();
 436        return 0;
 437}
 438
 439int main(int argc, char **argv)
 440{
 441        char *dir;
 442        int i;
 443        int strict = 0;
 444
 445        for (i = 1; i < argc; i++) {
 446                char *arg = argv[i];
 447
 448                if (arg[0] != '-')
 449                        break;
 450                if (!strcmp(arg, "--strict")) {
 451                        strict = 1;
 452                        continue;
 453                }
 454                if (!strncmp(arg, "--timeout=", 10)) {
 455                        timeout = atoi(arg+10);
 456                        continue;
 457                }
 458                if (!strcmp(arg, "--")) {
 459                        i++;
 460                        break;
 461                }
 462        }
 463        
 464        if (i != argc-1)
 465                usage(upload_pack_usage);
 466        dir = argv[i];
 467
 468        if (!enter_repo(dir, strict))
 469                die("'%s': unable to chdir or not a git archive", dir);
 470
 471        upload_pack();
 472        return 0;
 473}