Andrew's git / gitweb.git / run-command.c
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run-command.con commit Merge branch 'pw/p4' (98b256b)
   1#include "cache.h"
   2#include "run-command.h"
   3#include "exec_cmd.h"
   4
   5static inline void close_pair(int fd[2])
   6{
   7        close(fd[0]);
   8        close(fd[1]);
   9}
  10
  11#ifndef WIN32
  12static inline void dup_devnull(int to)
  13{
  14        int fd = open("/dev/null", O_RDWR);
  15        dup2(fd, to);
  16        close(fd);
  17}
  18#endif
  19
  20static const char **prepare_shell_cmd(const char **argv)
  21{
  22        int argc, nargc = 0;
  23        const char **nargv;
  24
  25        for (argc = 0; argv[argc]; argc++)
  26                ; /* just counting */
  27        /* +1 for NULL, +3 for "sh -c" plus extra $0 */
  28        nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
  29
  30        if (argc < 1)
  31                die("BUG: shell command is empty");
  32
  33        if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
  34                nargv[nargc++] = "sh";
  35                nargv[nargc++] = "-c";
  36
  37                if (argc < 2)
  38                        nargv[nargc++] = argv[0];
  39                else {
  40                        struct strbuf arg0 = STRBUF_INIT;
  41                        strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
  42                        nargv[nargc++] = strbuf_detach(&arg0, NULL);
  43                }
  44        }
  45
  46        for (argc = 0; argv[argc]; argc++)
  47                nargv[nargc++] = argv[argc];
  48        nargv[nargc] = NULL;
  49
  50        return nargv;
  51}
  52
  53#ifndef WIN32
  54static int execv_shell_cmd(const char **argv)
  55{
  56        const char **nargv = prepare_shell_cmd(argv);
  57        trace_argv_printf(nargv, "trace: exec:");
  58        execvp(nargv[0], (char **)nargv);
  59        free(nargv);
  60        return -1;
  61}
  62#endif
  63
  64#ifndef WIN32
  65static int child_err = 2;
  66static int child_notifier = -1;
  67
  68static void notify_parent(void)
  69{
  70        ssize_t unused;
  71        unused = write(child_notifier, "", 1);
  72}
  73
  74static NORETURN void die_child(const char *err, va_list params)
  75{
  76        char msg[4096];
  77        ssize_t unused;
  78        int len = vsnprintf(msg, sizeof(msg), err, params);
  79        if (len > sizeof(msg))
  80                len = sizeof(msg);
  81
  82        unused = write(child_err, "fatal: ", 7);
  83        unused = write(child_err, msg, len);
  84        unused = write(child_err, "\n", 1);
  85        exit(128);
  86}
  87#endif
  88
  89static inline void set_cloexec(int fd)
  90{
  91        int flags = fcntl(fd, F_GETFD);
  92        if (flags >= 0)
  93                fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
  94}
  95
  96static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
  97{
  98        int status, code = -1;
  99        pid_t waiting;
 100        int failed_errno = 0;
 101
 102        while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
 103                ;       /* nothing */
 104
 105        if (waiting < 0) {
 106                failed_errno = errno;
 107                error("waitpid for %s failed: %s", argv0, strerror(errno));
 108        } else if (waiting != pid) {
 109                error("waitpid is confused (%s)", argv0);
 110        } else if (WIFSIGNALED(status)) {
 111                code = WTERMSIG(status);
 112                error("%s died of signal %d", argv0, code);
 113                /*
 114                 * This return value is chosen so that code & 0xff
 115                 * mimics the exit code that a POSIX shell would report for
 116                 * a program that died from this signal.
 117                 */
 118                code -= 128;
 119        } else if (WIFEXITED(status)) {
 120                code = WEXITSTATUS(status);
 121                /*
 122                 * Convert special exit code when execvp failed.
 123                 */
 124                if (code == 127) {
 125                        code = -1;
 126                        failed_errno = ENOENT;
 127                        if (!silent_exec_failure)
 128                                error("cannot run %s: %s", argv0,
 129                                        strerror(ENOENT));
 130                }
 131        } else {
 132                error("waitpid is confused (%s)", argv0);
 133        }
 134        errno = failed_errno;
 135        return code;
 136}
 137
 138int start_command(struct child_process *cmd)
 139{
 140        int need_in, need_out, need_err;
 141        int fdin[2], fdout[2], fderr[2];
 142        int failed_errno = failed_errno;
 143
 144        /*
 145         * In case of errors we must keep the promise to close FDs
 146         * that have been passed in via ->in and ->out.
 147         */
 148
 149        need_in = !cmd->no_stdin && cmd->in < 0;
 150        if (need_in) {
 151                if (pipe(fdin) < 0) {
 152                        failed_errno = errno;
 153                        if (cmd->out > 0)
 154                                close(cmd->out);
 155                        goto fail_pipe;
 156                }
 157                cmd->in = fdin[1];
 158        }
 159
 160        need_out = !cmd->no_stdout
 161                && !cmd->stdout_to_stderr
 162                && cmd->out < 0;
 163        if (need_out) {
 164                if (pipe(fdout) < 0) {
 165                        failed_errno = errno;
 166                        if (need_in)
 167                                close_pair(fdin);
 168                        else if (cmd->in)
 169                                close(cmd->in);
 170                        goto fail_pipe;
 171                }
 172                cmd->out = fdout[0];
 173        }
 174
 175        need_err = !cmd->no_stderr && cmd->err < 0;
 176        if (need_err) {
 177                if (pipe(fderr) < 0) {
 178                        failed_errno = errno;
 179                        if (need_in)
 180                                close_pair(fdin);
 181                        else if (cmd->in)
 182                                close(cmd->in);
 183                        if (need_out)
 184                                close_pair(fdout);
 185                        else if (cmd->out)
 186                                close(cmd->out);
 187fail_pipe:
 188                        error("cannot create pipe for %s: %s",
 189                                cmd->argv[0], strerror(failed_errno));
 190                        errno = failed_errno;
 191                        return -1;
 192                }
 193                cmd->err = fderr[0];
 194        }
 195
 196        trace_argv_printf(cmd->argv, "trace: run_command:");
 197        fflush(NULL);
 198
 199#ifndef WIN32
 200{
 201        int notify_pipe[2];
 202        if (pipe(notify_pipe))
 203                notify_pipe[0] = notify_pipe[1] = -1;
 204
 205        cmd->pid = fork();
 206        if (!cmd->pid) {
 207                /*
 208                 * Redirect the channel to write syscall error messages to
 209                 * before redirecting the process's stderr so that all die()
 210                 * in subsequent call paths use the parent's stderr.
 211                 */
 212                if (cmd->no_stderr || need_err) {
 213                        child_err = dup(2);
 214                        set_cloexec(child_err);
 215                }
 216                set_die_routine(die_child);
 217
 218                close(notify_pipe[0]);
 219                set_cloexec(notify_pipe[1]);
 220                child_notifier = notify_pipe[1];
 221                atexit(notify_parent);
 222
 223                if (cmd->no_stdin)
 224                        dup_devnull(0);
 225                else if (need_in) {
 226                        dup2(fdin[0], 0);
 227                        close_pair(fdin);
 228                } else if (cmd->in) {
 229                        dup2(cmd->in, 0);
 230                        close(cmd->in);
 231                }
 232
 233                if (cmd->no_stderr)
 234                        dup_devnull(2);
 235                else if (need_err) {
 236                        dup2(fderr[1], 2);
 237                        close_pair(fderr);
 238                } else if (cmd->err > 1) {
 239                        dup2(cmd->err, 2);
 240                        close(cmd->err);
 241                }
 242
 243                if (cmd->no_stdout)
 244                        dup_devnull(1);
 245                else if (cmd->stdout_to_stderr)
 246                        dup2(2, 1);
 247                else if (need_out) {
 248                        dup2(fdout[1], 1);
 249                        close_pair(fdout);
 250                } else if (cmd->out > 1) {
 251                        dup2(cmd->out, 1);
 252                        close(cmd->out);
 253                }
 254
 255                if (cmd->dir && chdir(cmd->dir))
 256                        die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
 257                            cmd->dir);
 258                if (cmd->env) {
 259                        for (; *cmd->env; cmd->env++) {
 260                                if (strchr(*cmd->env, '='))
 261                                        putenv((char *)*cmd->env);
 262                                else
 263                                        unsetenv(*cmd->env);
 264                        }
 265                }
 266                if (cmd->preexec_cb) {
 267                        /*
 268                         * We cannot predict what the pre-exec callback does.
 269                         * Forgo parent notification.
 270                         */
 271                        close(child_notifier);
 272                        child_notifier = -1;
 273
 274                        cmd->preexec_cb();
 275                }
 276                if (cmd->git_cmd) {
 277                        execv_git_cmd(cmd->argv);
 278                } else if (cmd->use_shell) {
 279                        execv_shell_cmd(cmd->argv);
 280                } else {
 281                        execvp(cmd->argv[0], (char *const*) cmd->argv);
 282                }
 283                /*
 284                 * Do not check for cmd->silent_exec_failure; the parent
 285                 * process will check it when it sees this exit code.
 286                 */
 287                if (errno == ENOENT)
 288                        exit(127);
 289                else
 290                        die_errno("cannot exec '%s'", cmd->argv[0]);
 291        }
 292        if (cmd->pid < 0)
 293                error("cannot fork() for %s: %s", cmd->argv[0],
 294                        strerror(failed_errno = errno));
 295
 296        /*
 297         * Wait for child's execvp. If the execvp succeeds (or if fork()
 298         * failed), EOF is seen immediately by the parent. Otherwise, the
 299         * child process sends a single byte.
 300         * Note that use of this infrastructure is completely advisory,
 301         * therefore, we keep error checks minimal.
 302         */
 303        close(notify_pipe[1]);
 304        if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
 305                /*
 306                 * At this point we know that fork() succeeded, but execvp()
 307                 * failed. Errors have been reported to our stderr.
 308                 */
 309                wait_or_whine(cmd->pid, cmd->argv[0],
 310                              cmd->silent_exec_failure);
 311                failed_errno = errno;
 312                cmd->pid = -1;
 313        }
 314        close(notify_pipe[0]);
 315}
 316#else
 317{
 318        int fhin = 0, fhout = 1, fherr = 2;
 319        const char **sargv = cmd->argv;
 320        char **env = environ;
 321
 322        if (cmd->no_stdin)
 323                fhin = open("/dev/null", O_RDWR);
 324        else if (need_in)
 325                fhin = dup(fdin[0]);
 326        else if (cmd->in)
 327                fhin = dup(cmd->in);
 328
 329        if (cmd->no_stderr)
 330                fherr = open("/dev/null", O_RDWR);
 331        else if (need_err)
 332                fherr = dup(fderr[1]);
 333        else if (cmd->err > 2)
 334                fherr = dup(cmd->err);
 335
 336        if (cmd->no_stdout)
 337                fhout = open("/dev/null", O_RDWR);
 338        else if (cmd->stdout_to_stderr)
 339                fhout = dup(fherr);
 340        else if (need_out)
 341                fhout = dup(fdout[1]);
 342        else if (cmd->out > 1)
 343                fhout = dup(cmd->out);
 344
 345        if (cmd->env)
 346                env = make_augmented_environ(cmd->env);
 347
 348        if (cmd->git_cmd) {
 349                cmd->argv = prepare_git_cmd(cmd->argv);
 350        } else if (cmd->use_shell) {
 351                cmd->argv = prepare_shell_cmd(cmd->argv);
 352        }
 353
 354        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
 355                                  fhin, fhout, fherr);
 356        failed_errno = errno;
 357        if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 358                error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 359
 360        if (cmd->env)
 361                free_environ(env);
 362        if (cmd->git_cmd)
 363                free(cmd->argv);
 364
 365        cmd->argv = sargv;
 366        if (fhin != 0)
 367                close(fhin);
 368        if (fhout != 1)
 369                close(fhout);
 370        if (fherr != 2)
 371                close(fherr);
 372}
 373#endif
 374
 375        if (cmd->pid < 0) {
 376                if (need_in)
 377                        close_pair(fdin);
 378                else if (cmd->in)
 379                        close(cmd->in);
 380                if (need_out)
 381                        close_pair(fdout);
 382                else if (cmd->out)
 383                        close(cmd->out);
 384                if (need_err)
 385                        close_pair(fderr);
 386                else if (cmd->err)
 387                        close(cmd->err);
 388                errno = failed_errno;
 389                return -1;
 390        }
 391
 392        if (need_in)
 393                close(fdin[0]);
 394        else if (cmd->in)
 395                close(cmd->in);
 396
 397        if (need_out)
 398                close(fdout[1]);
 399        else if (cmd->out)
 400                close(cmd->out);
 401
 402        if (need_err)
 403                close(fderr[1]);
 404        else if (cmd->err)
 405                close(cmd->err);
 406
 407        return 0;
 408}
 409
 410int finish_command(struct child_process *cmd)
 411{
 412        return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
 413}
 414
 415int run_command(struct child_process *cmd)
 416{
 417        int code = start_command(cmd);
 418        if (code)
 419                return code;
 420        return finish_command(cmd);
 421}
 422
 423static void prepare_run_command_v_opt(struct child_process *cmd,
 424                                      const char **argv,
 425                                      int opt)
 426{
 427        memset(cmd, 0, sizeof(*cmd));
 428        cmd->argv = argv;
 429        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 430        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 431        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 432        cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 433        cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
 434}
 435
 436int run_command_v_opt(const char **argv, int opt)
 437{
 438        struct child_process cmd;
 439        prepare_run_command_v_opt(&cmd, argv, opt);
 440        return run_command(&cmd);
 441}
 442
 443int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 444{
 445        struct child_process cmd;
 446        prepare_run_command_v_opt(&cmd, argv, opt);
 447        cmd.dir = dir;
 448        cmd.env = env;
 449        return run_command(&cmd);
 450}
 451
 452#ifndef NO_PTHREADS
 453static pthread_t main_thread;
 454static int main_thread_set;
 455static pthread_key_t async_key;
 456
 457static void *run_thread(void *data)
 458{
 459        struct async *async = data;
 460        intptr_t ret;
 461
 462        pthread_setspecific(async_key, async);
 463        ret = async->proc(async->proc_in, async->proc_out, async->data);
 464        return (void *)ret;
 465}
 466
 467static NORETURN void die_async(const char *err, va_list params)
 468{
 469        vreportf("fatal: ", err, params);
 470
 471        if (!pthread_equal(main_thread, pthread_self())) {
 472                struct async *async = pthread_getspecific(async_key);
 473                if (async->proc_in >= 0)
 474                        close(async->proc_in);
 475                if (async->proc_out >= 0)
 476                        close(async->proc_out);
 477                pthread_exit((void *)128);
 478        }
 479
 480        exit(128);
 481}
 482#endif
 483
 484int start_async(struct async *async)
 485{
 486        int need_in, need_out;
 487        int fdin[2], fdout[2];
 488        int proc_in, proc_out;
 489
 490        need_in = async->in < 0;
 491        if (need_in) {
 492                if (pipe(fdin) < 0) {
 493                        if (async->out > 0)
 494                                close(async->out);
 495                        return error("cannot create pipe: %s", strerror(errno));
 496                }
 497                async->in = fdin[1];
 498        }
 499
 500        need_out = async->out < 0;
 501        if (need_out) {
 502                if (pipe(fdout) < 0) {
 503                        if (need_in)
 504                                close_pair(fdin);
 505                        else if (async->in)
 506                                close(async->in);
 507                        return error("cannot create pipe: %s", strerror(errno));
 508                }
 509                async->out = fdout[0];
 510        }
 511
 512        if (need_in)
 513                proc_in = fdin[0];
 514        else if (async->in)
 515                proc_in = async->in;
 516        else
 517                proc_in = -1;
 518
 519        if (need_out)
 520                proc_out = fdout[1];
 521        else if (async->out)
 522                proc_out = async->out;
 523        else
 524                proc_out = -1;
 525
 526#ifdef NO_PTHREADS
 527        /* Flush stdio before fork() to avoid cloning buffers */
 528        fflush(NULL);
 529
 530        async->pid = fork();
 531        if (async->pid < 0) {
 532                error("fork (async) failed: %s", strerror(errno));
 533                goto error;
 534        }
 535        if (!async->pid) {
 536                if (need_in)
 537                        close(fdin[1]);
 538                if (need_out)
 539                        close(fdout[0]);
 540                exit(!!async->proc(proc_in, proc_out, async->data));
 541        }
 542
 543        if (need_in)
 544                close(fdin[0]);
 545        else if (async->in)
 546                close(async->in);
 547
 548        if (need_out)
 549                close(fdout[1]);
 550        else if (async->out)
 551                close(async->out);
 552#else
 553        if (!main_thread_set) {
 554                /*
 555                 * We assume that the first time that start_async is called
 556                 * it is from the main thread.
 557                 */
 558                main_thread_set = 1;
 559                main_thread = pthread_self();
 560                pthread_key_create(&async_key, NULL);
 561                set_die_routine(die_async);
 562        }
 563
 564        if (proc_in >= 0)
 565                set_cloexec(proc_in);
 566        if (proc_out >= 0)
 567                set_cloexec(proc_out);
 568        async->proc_in = proc_in;
 569        async->proc_out = proc_out;
 570        {
 571                int err = pthread_create(&async->tid, NULL, run_thread, async);
 572                if (err) {
 573                        error("cannot create thread: %s", strerror(err));
 574                        goto error;
 575                }
 576        }
 577#endif
 578        return 0;
 579
 580error:
 581        if (need_in)
 582                close_pair(fdin);
 583        else if (async->in)
 584                close(async->in);
 585
 586        if (need_out)
 587                close_pair(fdout);
 588        else if (async->out)
 589                close(async->out);
 590        return -1;
 591}
 592
 593int finish_async(struct async *async)
 594{
 595#ifdef NO_PTHREADS
 596        return wait_or_whine(async->pid, "child process", 0);
 597#else
 598        void *ret = (void *)(intptr_t)(-1);
 599
 600        if (pthread_join(async->tid, &ret))
 601                error("pthread_join failed");
 602        return (int)(intptr_t)ret;
 603#endif
 604}
 605
 606int run_hook(const char *index_file, const char *name, ...)
 607{
 608        struct child_process hook;
 609        const char **argv = NULL, *env[2];
 610        char index[PATH_MAX];
 611        va_list args;
 612        int ret;
 613        size_t i = 0, alloc = 0;
 614
 615        if (access(git_path("hooks/%s", name), X_OK) < 0)
 616                return 0;
 617
 618        va_start(args, name);
 619        ALLOC_GROW(argv, i + 1, alloc);
 620        argv[i++] = git_path("hooks/%s", name);
 621        while (argv[i-1]) {
 622                ALLOC_GROW(argv, i + 1, alloc);
 623                argv[i++] = va_arg(args, const char *);
 624        }
 625        va_end(args);
 626
 627        memset(&hook, 0, sizeof(hook));
 628        hook.argv = argv;
 629        hook.no_stdin = 1;
 630        hook.stdout_to_stderr = 1;
 631        if (index_file) {
 632                snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 633                env[0] = index;
 634                env[1] = NULL;
 635                hook.env = env;
 636        }
 637
 638        ret = run_command(&hook);
 639        free(argv);
 640        return ret;
 641}