send-pack.con commit git-fetch: exit with non-zero status when fast-forward check fails (f64d7fd)
   1#include "cache.h"
   2#include "commit.h"
   3#include "tag.h"
   4#include "refs.h"
   5#include "pkt-line.h"
   6#include "exec_cmd.h"
   7
   8static const char send_pack_usage[] =
   9"git-send-pack [--all] [--exec=git-receive-pack] <remote> [<head>...]\n"
  10"  --all and explicit <head> specification are mutually exclusive.";
  11static const char *exec = "git-receive-pack";
  12static int verbose;
  13static int send_all;
  14static int force_update;
  15static int use_thin_pack;
  16
  17static int is_zero_sha1(const unsigned char *sha1)
  18{
  19        int i;
  20
  21        for (i = 0; i < 20; i++) {
  22                if (*sha1++)
  23                        return 0;
  24        }
  25        return 1;
  26}
  27
  28static void exec_pack_objects(void)
  29{
  30        static const char *args[] = {
  31                "pack-objects",
  32                "--all-progress",
  33                "--stdout",
  34                NULL
  35        };
  36        execv_git_cmd(args);
  37        die("git-pack-objects exec failed (%s)", strerror(errno));
  38}
  39
  40static void exec_rev_list(struct ref *refs)
  41{
  42        static const char *args[4];
  43        int i = 0;
  44
  45        args[i++] = "rev-list"; /* 0 */
  46        if (use_thin_pack)      /* 1 */
  47                args[i++] = "--objects-edge";
  48        else
  49                args[i++] = "--objects";
  50
  51        args[i++] = "--stdin";
  52
  53        args[i] = NULL;
  54        execv_git_cmd(args);
  55        die("git-rev-list exec failed (%s)", strerror(errno));
  56}
  57
  58/*
  59 * Run "rev-list --stdin | pack-objects" pipe.
  60 */
  61static void rev_list(int fd, struct ref *refs)
  62{
  63        int pipe_fd[2];
  64        pid_t pack_objects_pid;
  65
  66        if (pipe(pipe_fd) < 0)
  67                die("rev-list setup: pipe failed");
  68        pack_objects_pid = fork();
  69        if (!pack_objects_pid) {
  70                /* The child becomes pack-objects; reads from pipe
  71                 * and writes to the original fd
  72                 */
  73                dup2(pipe_fd[0], 0);
  74                dup2(fd, 1);
  75                close(pipe_fd[0]);
  76                close(pipe_fd[1]);
  77                close(fd);
  78                exec_pack_objects();
  79                die("pack-objects setup failed");
  80        }
  81        if (pack_objects_pid < 0)
  82                die("pack-objects fork failed");
  83
  84        /* We become rev-list --stdin; output goes to pipe. */
  85        dup2(pipe_fd[1], 1);
  86        close(pipe_fd[0]);
  87        close(pipe_fd[1]);
  88        close(fd);
  89        exec_rev_list(refs);
  90}
  91
  92/*
  93 * Create "rev-list --stdin | pack-objects" pipe and feed
  94 * the refs into the pipeline.
  95 */
  96static void rev_list_generate(int fd, struct ref *refs)
  97{
  98        int pipe_fd[2];
  99        pid_t rev_list_generate_pid;
 100
 101        if (pipe(pipe_fd) < 0)
 102                die("rev-list-generate setup: pipe failed");
 103        rev_list_generate_pid = fork();
 104        if (!rev_list_generate_pid) {
 105                /* The child becomes the "rev-list | pack-objects"
 106                 * pipeline.  It takes input from us, and its output
 107                 * goes to fd.
 108                 */
 109                dup2(pipe_fd[0], 0);
 110                dup2(fd, 1);
 111                close(pipe_fd[0]);
 112                close(pipe_fd[1]);
 113                close(fd);
 114                rev_list(fd, refs);
 115                die("rev-list setup failed");
 116        }
 117        if (rev_list_generate_pid < 0)
 118                die("rev-list-generate fork failed");
 119
 120        /* We feed the rev parameters to them.  We do not write into
 121         * fd nor read from the pipe.
 122         */
 123        close(pipe_fd[0]);
 124        close(fd);
 125        while (refs) {
 126                char buf[42];
 127
 128                if (!is_null_sha1(refs->old_sha1) &&
 129                    has_sha1_file(refs->old_sha1)) {
 130                        memcpy(buf + 1, sha1_to_hex(refs->old_sha1), 40);
 131                        buf[0] = '^';
 132                        buf[41] = '\n';
 133                        write(pipe_fd[1], buf, 42);
 134                }
 135                if (!is_null_sha1(refs->new_sha1)) {
 136                        memcpy(buf, sha1_to_hex(refs->new_sha1), 40);
 137                        buf[40] = '\n';
 138                        write(pipe_fd[1], buf, 41);
 139                }
 140                refs = refs->next;
 141        }
 142        close(pipe_fd[1]);
 143        // waitpid(rev_list_generate_pid);
 144        exit(0);
 145}
 146
 147/*
 148 * Make a pack stream and spit it out into file descriptor fd
 149 */
 150static void pack_objects(int fd, struct ref *refs)
 151{
 152        pid_t rev_list_pid;
 153
 154        rev_list_pid = fork();
 155        if (!rev_list_pid) {
 156                rev_list_generate(fd, refs);
 157                die("rev-list setup failed");
 158        }
 159        if (rev_list_pid < 0)
 160                die("rev-list fork failed");
 161        /*
 162         * We don't wait for the rev-list pipeline in the parent:
 163         * we end up waiting for the other end instead
 164         */
 165}
 166
 167static void unmark_and_free(struct commit_list *list, unsigned int mark)
 168{
 169        while (list) {
 170                struct commit_list *temp = list;
 171                temp->item->object.flags &= ~mark;
 172                list = temp->next;
 173                free(temp);
 174        }
 175}
 176
 177static int ref_newer(const unsigned char *new_sha1,
 178                     const unsigned char *old_sha1)
 179{
 180        struct object *o;
 181        struct commit *old, *new;
 182        struct commit_list *list, *used;
 183        int found = 0;
 184
 185        /* Both new and old must be commit-ish and new is descendant of
 186         * old.  Otherwise we require --force.
 187         */
 188        o = deref_tag(parse_object(old_sha1), NULL, 0);
 189        if (!o || o->type != OBJ_COMMIT)
 190                return 0;
 191        old = (struct commit *) o;
 192
 193        o = deref_tag(parse_object(new_sha1), NULL, 0);
 194        if (!o || o->type != OBJ_COMMIT)
 195                return 0;
 196        new = (struct commit *) o;
 197
 198        if (parse_commit(new) < 0)
 199                return 0;
 200
 201        used = list = NULL;
 202        commit_list_insert(new, &list);
 203        while (list) {
 204                new = pop_most_recent_commit(&list, 1);
 205                commit_list_insert(new, &used);
 206                if (new == old) {
 207                        found = 1;
 208                        break;
 209                }
 210        }
 211        unmark_and_free(list, 1);
 212        unmark_and_free(used, 1);
 213        return found;
 214}
 215
 216static struct ref *local_refs, **local_tail;
 217static struct ref *remote_refs, **remote_tail;
 218
 219static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 220{
 221        struct ref *ref;
 222        int len = strlen(refname) + 1;
 223        ref = xcalloc(1, sizeof(*ref) + len);
 224        hashcpy(ref->new_sha1, sha1);
 225        memcpy(ref->name, refname, len);
 226        *local_tail = ref;
 227        local_tail = &ref->next;
 228        return 0;
 229}
 230
 231static void get_local_heads(void)
 232{
 233        local_tail = &local_refs;
 234        for_each_ref(one_local_ref, NULL);
 235}
 236
 237static int receive_status(int in)
 238{
 239        char line[1000];
 240        int ret = 0;
 241        int len = packet_read_line(in, line, sizeof(line));
 242        if (len < 10 || memcmp(line, "unpack ", 7)) {
 243                fprintf(stderr, "did not receive status back\n");
 244                return -1;
 245        }
 246        if (memcmp(line, "unpack ok\n", 10)) {
 247                fputs(line, stderr);
 248                ret = -1;
 249        }
 250        while (1) {
 251                len = packet_read_line(in, line, sizeof(line));
 252                if (!len)
 253                        break;
 254                if (len < 3 ||
 255                    (memcmp(line, "ok", 2) && memcmp(line, "ng", 2))) {
 256                        fprintf(stderr, "protocol error: %s\n", line);
 257                        ret = -1;
 258                        break;
 259                }
 260                if (!memcmp(line, "ok", 2))
 261                        continue;
 262                fputs(line, stderr);
 263                ret = -1;
 264        }
 265        return ret;
 266}
 267
 268static int send_pack(int in, int out, int nr_refspec, char **refspec)
 269{
 270        struct ref *ref;
 271        int new_refs;
 272        int ret = 0;
 273        int ask_for_status_report = 0;
 274        int expect_status_report = 0;
 275
 276        /* No funny business with the matcher */
 277        remote_tail = get_remote_heads(in, &remote_refs, 0, NULL, REF_NORMAL);
 278        get_local_heads();
 279
 280        /* Does the other end support the reporting? */
 281        if (server_supports("report-status"))
 282                ask_for_status_report = 1;
 283
 284        /* match them up */
 285        if (!remote_tail)
 286                remote_tail = &remote_refs;
 287        if (match_refs(local_refs, remote_refs, &remote_tail,
 288                       nr_refspec, refspec, send_all))
 289                return -1;
 290
 291        if (!remote_refs) {
 292                fprintf(stderr, "No refs in common and none specified; doing nothing.\n");
 293                return 0;
 294        }
 295
 296        /*
 297         * Finally, tell the other end!
 298         */
 299        new_refs = 0;
 300        for (ref = remote_refs; ref; ref = ref->next) {
 301                char old_hex[60], *new_hex;
 302                if (!ref->peer_ref)
 303                        continue;
 304                if (!hashcmp(ref->old_sha1, ref->peer_ref->new_sha1)) {
 305                        if (verbose)
 306                                fprintf(stderr, "'%s': up-to-date\n", ref->name);
 307                        continue;
 308                }
 309
 310                /* This part determines what can overwrite what.
 311                 * The rules are:
 312                 *
 313                 * (0) you can always use --force or +A:B notation to
 314                 *     selectively force individual ref pairs.
 315                 *
 316                 * (1) if the old thing does not exist, it is OK.
 317                 *
 318                 * (2) if you do not have the old thing, you are not allowed
 319                 *     to overwrite it; you would not know what you are losing
 320                 *     otherwise.
 321                 *
 322                 * (3) if both new and old are commit-ish, and new is a
 323                 *     descendant of old, it is OK.
 324                 */
 325
 326                if (!force_update &&
 327                    !is_zero_sha1(ref->old_sha1) &&
 328                    !ref->force) {
 329                        if (!has_sha1_file(ref->old_sha1) ||
 330                            !ref_newer(ref->peer_ref->new_sha1,
 331                                       ref->old_sha1)) {
 332                                /* We do not have the remote ref, or
 333                                 * we know that the remote ref is not
 334                                 * an ancestor of what we are trying to
 335                                 * push.  Either way this can be losing
 336                                 * commits at the remote end and likely
 337                                 * we were not up to date to begin with.
 338                                 */
 339                                error("remote '%s' is not a strict "
 340                                      "subset of local ref '%s'. "
 341                                      "maybe you are not up-to-date and "
 342                                      "need to pull first?",
 343                                      ref->name,
 344                                      ref->peer_ref->name);
 345                                ret = -2;
 346                                continue;
 347                        }
 348                }
 349                hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
 350                if (is_zero_sha1(ref->new_sha1)) {
 351                        error("cannot happen anymore");
 352                        ret = -3;
 353                        continue;
 354                }
 355                new_refs++;
 356                strcpy(old_hex, sha1_to_hex(ref->old_sha1));
 357                new_hex = sha1_to_hex(ref->new_sha1);
 358
 359                if (ask_for_status_report) {
 360                        packet_write(out, "%s %s %s%c%s",
 361                                     old_hex, new_hex, ref->name, 0,
 362                                     "report-status");
 363                        ask_for_status_report = 0;
 364                        expect_status_report = 1;
 365                }
 366                else
 367                        packet_write(out, "%s %s %s",
 368                                     old_hex, new_hex, ref->name);
 369                fprintf(stderr, "updating '%s'", ref->name);
 370                if (strcmp(ref->name, ref->peer_ref->name))
 371                        fprintf(stderr, " using '%s'", ref->peer_ref->name);
 372                fprintf(stderr, "\n  from %s\n  to   %s\n", old_hex, new_hex);
 373        }
 374
 375        packet_flush(out);
 376        if (new_refs)
 377                pack_objects(out, remote_refs);
 378        close(out);
 379
 380        if (expect_status_report) {
 381                if (receive_status(in))
 382                        ret = -4;
 383        }
 384
 385        if (!new_refs && ret == 0)
 386                fprintf(stderr, "Everything up-to-date\n");
 387        return ret;
 388}
 389
 390
 391int main(int argc, char **argv)
 392{
 393        int i, nr_heads = 0;
 394        char *dest = NULL;
 395        char **heads = NULL;
 396        int fd[2], ret;
 397        pid_t pid;
 398
 399        setup_git_directory();
 400        git_config(git_default_config);
 401
 402        argv++;
 403        for (i = 1; i < argc; i++, argv++) {
 404                char *arg = *argv;
 405
 406                if (*arg == '-') {
 407                        if (!strncmp(arg, "--exec=", 7)) {
 408                                exec = arg + 7;
 409                                continue;
 410                        }
 411                        if (!strcmp(arg, "--all")) {
 412                                send_all = 1;
 413                                continue;
 414                        }
 415                        if (!strcmp(arg, "--force")) {
 416                                force_update = 1;
 417                                continue;
 418                        }
 419                        if (!strcmp(arg, "--verbose")) {
 420                                verbose = 1;
 421                                continue;
 422                        }
 423                        if (!strcmp(arg, "--thin")) {
 424                                use_thin_pack = 1;
 425                                continue;
 426                        }
 427                        usage(send_pack_usage);
 428                }
 429                if (!dest) {
 430                        dest = arg;
 431                        continue;
 432                }
 433                heads = argv;
 434                nr_heads = argc - i;
 435                break;
 436        }
 437        if (!dest)
 438                usage(send_pack_usage);
 439        if (heads && send_all)
 440                usage(send_pack_usage);
 441        pid = git_connect(fd, dest, exec);
 442        if (pid < 0)
 443                return 1;
 444        ret = send_pack(fd[0], fd[1], nr_heads, heads);
 445        close(fd[0]);
 446        close(fd[1]);
 447        ret |= finish_connect(pid);
 448        return !!ret;
 449}