Andrew's git - gitweb.git/blob

   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        write(child_notifier, "", 1);
  71}
  72
  73static NORETURN void die_child(const char *err, va_list params)
  74{
  75        char msg[4096];
  76        int len = vsnprintf(msg, sizeof(msg), err, params);
  77        if (len > sizeof(msg))
  78                len = sizeof(msg);
  79
  80        write(child_err, "fatal: ", 7);
  81        write(child_err, msg, len);
  82        write(child_err, "\n", 1);
  83        exit(128);
  84}
  85
  86static inline void set_cloexec(int fd)
  87{
  88        int flags = fcntl(fd, F_GETFD);
  89        if (flags >= 0)
  90                fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
  91}
  92#endif
  93
  94static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
  95{
  96        int status, code = -1;
  97        pid_t waiting;
  98        int failed_errno = 0;
  99
 100        while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
 101                ;       /* nothing */
 102
 103        if (waiting < 0) {
 104                failed_errno = errno;
 105                error("waitpid for %s failed: %s", argv0, strerror(errno));
 106        } else if (waiting != pid) {
 107                error("waitpid is confused (%s)", argv0);
 108        } else if (WIFSIGNALED(status)) {
 109                code = WTERMSIG(status);
 110                error("%s died of signal %d", argv0, code);
 111                /*
 112                 * This return value is chosen so that code & 0xff
 113                 * mimics the exit code that a POSIX shell would report for
 114                 * a program that died from this signal.
 115                 */
 116                code -= 128;
 117        } else if (WIFEXITED(status)) {
 118                code = WEXITSTATUS(status);
 119                /*
 120                 * Convert special exit code when execvp failed.
 121                 */
 122                if (code == 127) {
 123                        code = -1;
 124                        failed_errno = ENOENT;
 125                        if (!silent_exec_failure)
 126                                error("cannot run %s: %s", argv0,
 127                                        strerror(ENOENT));
 128                }
 129        } else {
 130                error("waitpid is confused (%s)", argv0);
 131        }
 132        errno = failed_errno;
 133        return code;
 134}
 135
 136int start_command(struct child_process *cmd)
 137{
 138        int need_in, need_out, need_err;
 139        int fdin[2], fdout[2], fderr[2];
 140        int failed_errno = failed_errno;
 141
 142        /*
 143         * In case of errors we must keep the promise to close FDs
 144         * that have been passed in via ->in and ->out.
 145         */
 146
 147        need_in = !cmd->no_stdin && cmd->in < 0;
 148        if (need_in) {
 149                if (pipe(fdin) < 0) {
 150                        failed_errno = errno;
 151                        if (cmd->out > 0)
 152                                close(cmd->out);
 153                        goto fail_pipe;
 154                }
 155                cmd->in = fdin[1];
 156        }
 157
 158        need_out = !cmd->no_stdout
 159                && !cmd->stdout_to_stderr
 160                && cmd->out < 0;
 161        if (need_out) {
 162                if (pipe(fdout) < 0) {
 163                        failed_errno = errno;
 164                        if (need_in)
 165                                close_pair(fdin);
 166                        else if (cmd->in)
 167                                close(cmd->in);
 168                        goto fail_pipe;
 169                }
 170                cmd->out = fdout[0];
 171        }
 172
 173        need_err = !cmd->no_stderr && cmd->err < 0;
 174        if (need_err) {
 175                if (pipe(fderr) < 0) {
 176                        failed_errno = errno;
 177                        if (need_in)
 178                                close_pair(fdin);
 179                        else if (cmd->in)
 180                                close(cmd->in);
 181                        if (need_out)
 182                                close_pair(fdout);
 183                        else if (cmd->out)
 184                                close(cmd->out);
 185fail_pipe:
 186                        error("cannot create pipe for %s: %s",
 187                                cmd->argv[0], strerror(failed_errno));
 188                        errno = failed_errno;
 189                        return -1;
 190                }
 191                cmd->err = fderr[0];
 192        }
 193
 194        trace_argv_printf(cmd->argv, "trace: run_command:");
 195
 196#ifndef WIN32
 197{
 198        int notify_pipe[2];
 199        if (pipe(notify_pipe))
 200                notify_pipe[0] = notify_pipe[1] = -1;
 201
 202        fflush(NULL);
 203        cmd->pid = fork();
 204        if (!cmd->pid) {
 205                /*
 206                 * Redirect the channel to write syscall error messages to
 207                 * before redirecting the process's stderr so that all die()
 208                 * in subsequent call paths use the parent's stderr.
 209                 */
 210                if (cmd->no_stderr || need_err) {
 211                        child_err = dup(2);
 212                        set_cloexec(child_err);
 213                }
 214                set_die_routine(die_child);
 215
 216                close(notify_pipe[0]);
 217                set_cloexec(notify_pipe[1]);
 218                child_notifier = notify_pipe[1];
 219                atexit(notify_parent);
 220
 221                if (cmd->no_stdin)
 222                        dup_devnull(0);
 223                else if (need_in) {
 224                        dup2(fdin[0], 0);
 225                        close_pair(fdin);
 226                } else if (cmd->in) {
 227                        dup2(cmd->in, 0);
 228                        close(cmd->in);
 229                }
 230
 231                if (cmd->no_stderr)
 232                        dup_devnull(2);
 233                else if (need_err) {
 234                        dup2(fderr[1], 2);
 235                        close_pair(fderr);
 236                }
 237
 238                if (cmd->no_stdout)
 239                        dup_devnull(1);
 240                else if (cmd->stdout_to_stderr)
 241                        dup2(2, 1);
 242                else if (need_out) {
 243                        dup2(fdout[1], 1);
 244                        close_pair(fdout);
 245                } else if (cmd->out > 1) {
 246                        dup2(cmd->out, 1);
 247                        close(cmd->out);
 248                }
 249
 250                if (cmd->dir && chdir(cmd->dir))
 251                        die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
 252                            cmd->dir);
 253                if (cmd->env) {
 254                        for (; *cmd->env; cmd->env++) {
 255                                if (strchr(*cmd->env, '='))
 256                                        putenv((char *)*cmd->env);
 257                                else
 258                                        unsetenv(*cmd->env);
 259                        }
 260                }
 261                if (cmd->preexec_cb) {
 262                        /*
 263                         * We cannot predict what the pre-exec callback does.
 264                         * Forgo parent notification.
 265                         */
 266                        close(child_notifier);
 267                        child_notifier = -1;
 268
 269                        cmd->preexec_cb();
 270                }
 271                if (cmd->git_cmd) {
 272                        execv_git_cmd(cmd->argv);
 273                } else if (cmd->use_shell) {
 274                        execv_shell_cmd(cmd->argv);
 275                } else {
 276                        execvp(cmd->argv[0], (char *const*) cmd->argv);
 277                }
 278                /*
 279                 * Do not check for cmd->silent_exec_failure; the parent
 280                 * process will check it when it sees this exit code.
 281                 */
 282                if (errno == ENOENT)
 283                        exit(127);
 284                else
 285                        die_errno("cannot exec '%s'", cmd->argv[0]);
 286        }
 287        if (cmd->pid < 0)
 288                error("cannot fork() for %s: %s", cmd->argv[0],
 289                        strerror(failed_errno = errno));
 290
 291        /*
 292         * Wait for child's execvp. If the execvp succeeds (or if fork()
 293         * failed), EOF is seen immediately by the parent. Otherwise, the
 294         * child process sends a single byte.
 295         * Note that use of this infrastructure is completely advisory,
 296         * therefore, we keep error checks minimal.
 297         */
 298        close(notify_pipe[1]);
 299        if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
 300                /*
 301                 * At this point we know that fork() succeeded, but execvp()
 302                 * failed. Errors have been reported to our stderr.
 303                 */
 304                wait_or_whine(cmd->pid, cmd->argv[0],
 305                              cmd->silent_exec_failure);
 306                failed_errno = errno;
 307                cmd->pid = -1;
 308        }
 309        close(notify_pipe[0]);
 310}
 311#else
 312{
 313        int fhin = 0, fhout = 1, fherr = 2;
 314        const char **sargv = cmd->argv;
 315        char **env = environ;
 316
 317        if (cmd->no_stdin)
 318                fhin = open("/dev/null", O_RDWR);
 319        else if (need_in)
 320                fhin = dup(fdin[0]);
 321        else if (cmd->in)
 322                fhin = dup(cmd->in);
 323
 324        if (cmd->no_stderr)
 325                fherr = open("/dev/null", O_RDWR);
 326        else if (need_err)
 327                fherr = dup(fderr[1]);
 328
 329        if (cmd->no_stdout)
 330                fhout = open("/dev/null", O_RDWR);
 331        else if (cmd->stdout_to_stderr)
 332                fhout = dup(fherr);
 333        else if (need_out)
 334                fhout = dup(fdout[1]);
 335        else if (cmd->out > 1)
 336                fhout = dup(cmd->out);
 337
 338        if (cmd->dir)
 339                die("chdir in start_command() not implemented");
 340        if (cmd->env)
 341                env = make_augmented_environ(cmd->env);
 342
 343        if (cmd->git_cmd) {
 344                cmd->argv = prepare_git_cmd(cmd->argv);
 345        } else if (cmd->use_shell) {
 346                cmd->argv = prepare_shell_cmd(cmd->argv);
 347        }
 348
 349        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env,
 350                                  fhin, fhout, fherr);
 351        failed_errno = errno;
 352        if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 353                error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 354
 355        if (cmd->env)
 356                free_environ(env);
 357        if (cmd->git_cmd)
 358                free(cmd->argv);
 359
 360        cmd->argv = sargv;
 361        if (fhin != 0)
 362                close(fhin);
 363        if (fhout != 1)
 364                close(fhout);
 365        if (fherr != 2)
 366                close(fherr);
 367}
 368#endif
 369
 370        if (cmd->pid < 0) {
 371                if (need_in)
 372                        close_pair(fdin);
 373                else if (cmd->in)
 374                        close(cmd->in);
 375                if (need_out)
 376                        close_pair(fdout);
 377                else if (cmd->out)
 378                        close(cmd->out);
 379                if (need_err)
 380                        close_pair(fderr);
 381                errno = failed_errno;
 382                return -1;
 383        }
 384
 385        if (need_in)
 386                close(fdin[0]);
 387        else if (cmd->in)
 388                close(cmd->in);
 389
 390        if (need_out)
 391                close(fdout[1]);
 392        else if (cmd->out)
 393                close(cmd->out);
 394
 395        if (need_err)
 396                close(fderr[1]);
 397
 398        return 0;
 399}
 400
 401int finish_command(struct child_process *cmd)
 402{
 403        return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
 404}
 405
 406int run_command(struct child_process *cmd)
 407{
 408        int code = start_command(cmd);
 409        if (code)
 410                return code;
 411        return finish_command(cmd);
 412}
 413
 414static void prepare_run_command_v_opt(struct child_process *cmd,
 415                                      const char **argv,
 416                                      int opt)
 417{
 418        memset(cmd, 0, sizeof(*cmd));
 419        cmd->argv = argv;
 420        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 421        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 422        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 423        cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 424        cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
 425}
 426
 427int run_command_v_opt(const char **argv, int opt)
 428{
 429        struct child_process cmd;
 430        prepare_run_command_v_opt(&cmd, argv, opt);
 431        return run_command(&cmd);
 432}
 433
 434int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 435{
 436        struct child_process cmd;
 437        prepare_run_command_v_opt(&cmd, argv, opt);
 438        cmd.dir = dir;
 439        cmd.env = env;
 440        return run_command(&cmd);
 441}
 442
 443#ifdef WIN32
 444static unsigned __stdcall run_thread(void *data)
 445{
 446        struct async *async = data;
 447        return async->proc(async->fd_for_proc, async->data);
 448}
 449#endif
 450
 451int start_async(struct async *async)
 452{
 453        int pipe_out[2];
 454
 455        if (pipe(pipe_out) < 0)
 456                return error("cannot create pipe: %s", strerror(errno));
 457        async->out = pipe_out[0];
 458
 459#ifndef WIN32
 460        /* Flush stdio before fork() to avoid cloning buffers */
 461        fflush(NULL);
 462
 463        async->pid = fork();
 464        if (async->pid < 0) {
 465                error("fork (async) failed: %s", strerror(errno));
 466                close_pair(pipe_out);
 467                return -1;
 468        }
 469        if (!async->pid) {
 470                close(pipe_out[0]);
 471                exit(!!async->proc(pipe_out[1], async->data));
 472        }
 473        close(pipe_out[1]);
 474#else
 475        async->fd_for_proc = pipe_out[1];
 476        async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 477        if (!async->tid) {
 478                error("cannot create thread: %s", strerror(errno));
 479                close_pair(pipe_out);
 480                return -1;
 481        }
 482#endif
 483        return 0;
 484}
 485
 486int finish_async(struct async *async)
 487{
 488#ifndef WIN32
 489        int ret = wait_or_whine(async->pid, "child process", 0);
 490#else
 491        DWORD ret = 0;
 492        if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 493                ret = error("waiting for thread failed: %lu", GetLastError());
 494        else if (!GetExitCodeThread(async->tid, &ret))
 495                ret = error("cannot get thread exit code: %lu", GetLastError());
 496        CloseHandle(async->tid);
 497#endif
 498        return ret;
 499}
 500
 501int run_hook(const char *index_file, const char *name, ...)
 502{
 503        struct child_process hook;
 504        const char **argv = NULL, *env[2];
 505        char index[PATH_MAX];
 506        va_list args;
 507        int ret;
 508        size_t i = 0, alloc = 0;
 509
 510        if (access(git_path("hooks/%s", name), X_OK) < 0)
 511                return 0;
 512
 513        va_start(args, name);
 514        ALLOC_GROW(argv, i + 1, alloc);
 515        argv[i++] = git_path("hooks/%s", name);
 516        while (argv[i-1]) {
 517                ALLOC_GROW(argv, i + 1, alloc);
 518                argv[i++] = va_arg(args, const char *);
 519        }
 520        va_end(args);
 521
 522        memset(&hook, 0, sizeof(hook));
 523        hook.argv = argv;
 524        hook.no_stdin = 1;
 525        hook.stdout_to_stderr = 1;
 526        if (index_file) {
 527                snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 528                env[0] = index;
 529                env[1] = NULL;
 530                hook.env = env;
 531        }
 532
 533        ret = run_command(&hook);
 534        free(argv);
 535        return ret;
 536}