run-command.c

   1 #include "cache.h"
   2 #include "run-command.h"
   3 #include "exec_cmd.h"
   4
   5 static inline void close_pair(int fd[2])
   6 {
   7         close(fd[0]);
   8         close(fd[1]);
   9 }
  10
  11 #ifndef WIN32
  12 static 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
  20 static 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
  54 static 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 int start_command(struct child_process *cmd)
  65 {
  66         int need_in, need_out, need_err;
  67         int fdin[2], fdout[2], fderr[2];
  68         int failed_errno = failed_errno;
  69
  70         /*
  71          * In case of errors we must keep the promise to close FDs
  72          * that have been passed in via ->in and ->out.
  73          */
  74
  75         need_in = !cmd->no_stdin && cmd->in < 0;
  76         if (need_in) {
  77                 if (pipe(fdin) < 0) {
  78                         failed_errno = errno;
  79                         if (cmd->out > 0)
  80                                 close(cmd->out);
  81                         goto fail_pipe;
  82                 }
  83                 cmd->in = fdin[1];
  84         }
  85
  86         need_out = !cmd->no_stdout
  87                 && !cmd->stdout_to_stderr
  88                 && cmd->out < 0;
  89         if (need_out) {
  90                 if (pipe(fdout) < 0) {
  91                         failed_errno = errno;
  92                         if (need_in)
  93                                 close_pair(fdin);
  94                         else if (cmd->in)
  95                                 close(cmd->in);
  96                         goto fail_pipe;
  97                 }
  98                 cmd->out = fdout[0];
  99         }
 100
 101         need_err = !cmd->no_stderr && cmd->err < 0;
 102         if (need_err) {
 103                 if (pipe(fderr) < 0) {
 104                         failed_errno = errno;
 105                         if (need_in)
 106                                 close_pair(fdin);
 107                         else if (cmd->in)
 108                                 close(cmd->in);
 109                         if (need_out)
 110                                 close_pair(fdout);
 111                         else if (cmd->out)
 112                                 close(cmd->out);
 113 fail_pipe:
 114                         error("cannot create pipe for %s: %s",
 115                                 cmd->argv[0], strerror(failed_errno));
 116                         errno = failed_errno;
 117                         return -1;
 118                 }
 119                 cmd->err = fderr[0];
 120         }
 121
 122         trace_argv_printf(cmd->argv, "trace: run_command:");
 123
 124 #ifndef WIN32
 125         fflush(NULL);
 126         cmd->pid = fork();
 127         if (!cmd->pid) {
 128                 if (cmd->no_stdin)
 129                         dup_devnull(0);
 130                 else if (need_in) {
 131                         dup2(fdin[0], 0);
 132                         close_pair(fdin);
 133                 } else if (cmd->in) {
 134                         dup2(cmd->in, 0);
 135                         close(cmd->in);
 136                 }
 137
 138                 if (cmd->no_stderr)
 139                         dup_devnull(2);
 140                 else if (need_err) {
 141                         dup2(fderr[1], 2);
 142                         close_pair(fderr);
 143                 }
 144
 145                 if (cmd->no_stdout)
 146                         dup_devnull(1);
 147                 else if (cmd->stdout_to_stderr)
 148                         dup2(2, 1);
 149                 else if (need_out) {
 150                         dup2(fdout[1], 1);
 151                         close_pair(fdout);
 152                 } else if (cmd->out > 1) {
 153                         dup2(cmd->out, 1);
 154                         close(cmd->out);
 155                 }
 156
 157                 if (cmd->dir && chdir(cmd->dir))
 158                         die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
 159                             cmd->dir);
 160                 if (cmd->env) {
 161                         for (; *cmd->env; cmd->env++) {
 162                                 if (strchr(*cmd->env, '='))
 163                                         putenv((char *)*cmd->env);
 164                                 else
 165                                         unsetenv(*cmd->env);
 166                         }
 167                 }
 168                 if (cmd->preexec_cb)
 169                         cmd->preexec_cb();
 170                 if (cmd->git_cmd) {
 171                         execv_git_cmd(cmd->argv);
 172                 } else if (cmd->use_shell) {
 173                         execv_shell_cmd(cmd->argv);
 174                 } else {
 175                         execvp(cmd->argv[0], (char *const*) cmd->argv);
 176                 }
 177                 trace_printf("trace: exec '%s' failed: %s\n", cmd->argv[0],
 178                                 strerror(errno));
 179                 exit(127);
 180         }
 181         if (cmd->pid < 0)
 182                 error("cannot fork() for %s: %s", cmd->argv[0],
 183                         strerror(failed_errno = errno));
 184 #else
 185 {
 186         int fhin = 0, fhout = 1, fherr = 2;
 187         const char **sargv = cmd->argv;
 188         char **env = environ;
 189
 190         if (cmd->no_stdin)
 191                 fhin = open("/dev/null", O_RDWR);
 192         else if (need_in)
 193                 fhin = dup(fdin[0]);
 194         else if (cmd->in)
 195                 fhin = dup(cmd->in);
 196
 197         if (cmd->no_stderr)
 198                 fherr = open("/dev/null", O_RDWR);
 199         else if (need_err)
 200                 fherr = dup(fderr[1]);
 201
 202         if (cmd->no_stdout)
 203                 fhout = open("/dev/null", O_RDWR);
 204         else if (cmd->stdout_to_stderr)
 205                 fhout = dup(fherr);
 206         else if (need_out)
 207                 fhout = dup(fdout[1]);
 208         else if (cmd->out > 1)
 209                 fhout = dup(cmd->out);
 210
 211         if (cmd->dir)
 212                 die("chdir in start_command() not implemented");
 213         if (cmd->env)
 214                 env = make_augmented_environ(cmd->env);
 215
 216         if (cmd->git_cmd) {
 217                 cmd->argv = prepare_git_cmd(cmd->argv);
 218         } else if (cmd->use_shell) {
 219                 cmd->argv = prepare_shell_cmd(cmd->argv);
 220         }
 221
 222         cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env,
 223                                   fhin, fhout, fherr);
 224         failed_errno = errno;
 225         if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 226                 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 227
 228         if (cmd->env)
 229                 free_environ(env);
 230         if (cmd->git_cmd)
 231                 free(cmd->argv);
 232
 233         cmd->argv = sargv;
 234         if (fhin != 0)
 235                 close(fhin);
 236         if (fhout != 1)
 237                 close(fhout);
 238         if (fherr != 2)
 239                 close(fherr);
 240 }
 241 #endif
 242
 243         if (cmd->pid < 0) {
 244                 if (need_in)
 245                         close_pair(fdin);
 246                 else if (cmd->in)
 247                         close(cmd->in);
 248                 if (need_out)
 249                         close_pair(fdout);
 250                 else if (cmd->out)
 251                         close(cmd->out);
 252                 if (need_err)
 253                         close_pair(fderr);
 254                 errno = failed_errno;
 255                 return -1;
 256         }
 257
 258         if (need_in)
 259                 close(fdin[0]);
 260         else if (cmd->in)
 261                 close(cmd->in);
 262
 263         if (need_out)
 264                 close(fdout[1]);
 265         else if (cmd->out)
 266                 close(cmd->out);
 267
 268         if (need_err)
 269                 close(fderr[1]);
 270
 271         return 0;
 272 }
 273
 274 static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
 275 {
 276         int status, code = -1;
 277         pid_t waiting;
 278         int failed_errno = 0;
 279
 280         while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
 281                 ;       /* nothing */
 282
 283         if (waiting < 0) {
 284                 failed_errno = errno;
 285                 error("waitpid for %s failed: %s", argv0, strerror(errno));
 286         } else if (waiting != pid) {
 287                 error("waitpid is confused (%s)", argv0);
 288         } else if (WIFSIGNALED(status)) {
 289                 code = WTERMSIG(status);
 290                 error("%s died of signal %d", argv0, code);
 291                 /*
 292                  * This return value is chosen so that code & 0xff
 293                  * mimics the exit code that a POSIX shell would report for
 294                  * a program that died from this signal.
 295                  */
 296                 code -= 128;
 297         } else if (WIFEXITED(status)) {
 298                 code = WEXITSTATUS(status);
 299                 /*
 300                  * Convert special exit code when execvp failed.
 301                  */
 302                 if (code == 127) {
 303                         code = -1;
 304                         failed_errno = ENOENT;
 305                         if (!silent_exec_failure)
 306                                 error("cannot run %s: %s", argv0,
 307                                         strerror(ENOENT));
 308                 }
 309         } else {
 310                 error("waitpid is confused (%s)", argv0);
 311         }
 312         errno = failed_errno;
 313         return code;
 314 }
 315
 316 int finish_command(struct child_process *cmd)
 317 {
 318         return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
 319 }
 320
 321 int run_command(struct child_process *cmd)
 322 {
 323         int code = start_command(cmd);
 324         if (code)
 325                 return code;
 326         return finish_command(cmd);
 327 }
 328
 329 static void prepare_run_command_v_opt(struct child_process *cmd,
 330                                       const char **argv,
 331                                       int opt)
 332 {
 333         memset(cmd, 0, sizeof(*cmd));
 334         cmd->argv = argv;
 335         cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 336         cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 337         cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 338         cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 339         cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
 340 }
 341
 342 int run_command_v_opt(const char **argv, int opt)
 343 {
 344         struct child_process cmd;
 345         prepare_run_command_v_opt(&cmd, argv, opt);
 346         return run_command(&cmd);
 347 }
 348
 349 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 350 {
 351         struct child_process cmd;
 352         prepare_run_command_v_opt(&cmd, argv, opt);
 353         cmd.dir = dir;
 354         cmd.env = env;
 355         return run_command(&cmd);
 356 }
 357
 358 #ifdef WIN32
 359 static unsigned __stdcall run_thread(void *data)
 360 {
 361         struct async *async = data;
 362         return async->proc(async->fd_for_proc, async->data);
 363 }
 364 #endif
 365
 366 int start_async(struct async *async)
 367 {
 368         int pipe_out[2];
 369
 370         if (pipe(pipe_out) < 0)
 371                 return error("cannot create pipe: %s", strerror(errno));
 372         async->out = pipe_out[0];
 373
 374 #ifndef WIN32
 375         /* Flush stdio before fork() to avoid cloning buffers */
 376         fflush(NULL);
 377
 378         async->pid = fork();
 379         if (async->pid < 0) {
 380                 error("fork (async) failed: %s", strerror(errno));
 381                 close_pair(pipe_out);
 382                 return -1;
 383         }
 384         if (!async->pid) {
 385                 close(pipe_out[0]);
 386                 exit(!!async->proc(pipe_out[1], async->data));
 387         }
 388         close(pipe_out[1]);
 389 #else
 390         async->fd_for_proc = pipe_out[1];
 391         async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 392         if (!async->tid) {
 393                 error("cannot create thread: %s", strerror(errno));
 394                 close_pair(pipe_out);
 395                 return -1;
 396         }
 397 #endif
 398         return 0;
 399 }
 400
 401 int finish_async(struct async *async)
 402 {
 403 #ifndef WIN32
 404         int ret = wait_or_whine(async->pid, "child process", 0);
 405 #else
 406         DWORD ret = 0;
 407         if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 408                 ret = error("waiting for thread failed: %lu", GetLastError());
 409         else if (!GetExitCodeThread(async->tid, &ret))
 410                 ret = error("cannot get thread exit code: %lu", GetLastError());
 411         CloseHandle(async->tid);
 412 #endif
 413         return ret;
 414 }
 415
 416 int run_hook(const char *index_file, const char *name, ...)
 417 {
 418         struct child_process hook;
 419         const char **argv = NULL, *env[2];
 420         char index[PATH_MAX];
 421         va_list args;
 422         int ret;
 423         size_t i = 0, alloc = 0;
 424
 425         if (access(git_path("hooks/%s", name), X_OK) < 0)
 426                 return 0;
 427
 428         va_start(args, name);
 429         ALLOC_GROW(argv, i + 1, alloc);
 430         argv[i++] = git_path("hooks/%s", name);
 431         while (argv[i-1]) {
 432                 ALLOC_GROW(argv, i + 1, alloc);
 433                 argv[i++] = va_arg(args, const char *);
 434         }
 435         va_end(args);
 436
 437         memset(&hook, 0, sizeof(hook));
 438         hook.argv = argv;
 439         hook.no_stdin = 1;
 440         hook.stdout_to_stderr = 1;
 441         if (index_file) {
 442                 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 443                 env[0] = index;
 444                 env[1] = NULL;
 445                 hook.env = env;
 446         }
 447
 448         ret = run_command(&hook);
 449         free(argv);
 450         return ret;
 451 }