mono/eglib/gspawn.c

   1 /*
   2  * Spawning processes.
   3  *
   4  * Author:
   5  *   Gonzalo Paniagua Javier (gonzalo@novell.com
   6  *
   7  * (C) 2006 Novell, Inc.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining
  10  * a copy of this software and associated documentation files (the
  11  * "Software"), to deal in the Software without restriction, including
  12  * without limitation the rights to use, copy, modify, merge, publish,
  13  * distribute, sublicense, and/or sell copies of the Software, and to
  14  * permit persons to whom the Software is furnished to do so, subject to
  15  * the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be
  18  * included in all copies or substantial portions of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27  */
  28 #include <config.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <errno.h>
  32 #include <fcntl.h>
  33 #include <sys/types.h>
  34
  35 #include <glib.h>
  36
  37 #ifdef HAVE_UNISTD_H
  38 #ifndef __USE_GNU
  39 #define __USE_GNU
  40 #endif
  41 #include <unistd.h>
  42 #endif
  43
  44 #ifdef HAVE_SYS_SELECT_H
  45 #include <sys/select.h>
  46 #endif
  47
  48 #ifdef HAVE_SYS_TIME_H
  49 #include <sys/time.h>
  50 #endif
  51
  52 #ifdef HAVE_SYS_WAIT_H
  53 #include <sys/wait.h>
  54 #endif
  55
  56 #ifdef HAVE_SYS_RESOURCE_H
  57 #  include <sys/resource.h>
  58 #endif
  59
  60 #ifdef G_OS_WIN32
  61 #include <io.h>
  62 #include <winsock2.h>
  63 #define open _open
  64 #define close _close
  65 #define read _read
  66 #define write _write
  67 /* windows pipe api details: http://msdn2.microsoft.com/en-us/library/edze9h7e(VS.80).aspx */
  68 #define pipe(x) _pipe(x, 256, 0)
  69 #endif
  70
  71 #define set_error(msg, ...) do { if (gerror != NULL) *gerror = g_error_new (G_LOG_DOMAIN, 1, msg, __VA_ARGS__); } while (0)
  72 #define set_error_cond(cond,msg, ...) do { if ((cond) && gerror != NULL) *gerror = g_error_new (G_LOG_DOMAIN, 1, msg, __VA_ARGS__); } while (0)
  73 #define set_error_status(status,msg, ...) do { if (gerror != NULL) *gerror = g_error_new (G_LOG_DOMAIN, status, msg, __VA_ARGS__); } while (0)
  74 #define NO_INTR(var,cmd) do { (var) = (cmd); } while ((var) == -1 && errno == EINTR)
  75 #define CLOSE_PIPE(p) do { close (p [0]); close (p [1]); } while (0)
  76
  77 #if defined(__APPLE__)
  78 #if defined (TARGET_OSX)
  79 /* Apple defines this in crt_externs.h but doesn't provide that header for
  80  * arm-apple-darwin9.  We'll manually define the symbol on Apple as it does
  81  * in fact exist on all implementations (so far)
  82  */
  83 G_BEGIN_DECLS
  84 gchar ***_NSGetEnviron(void);
  85 G_END_DECLS
  86 #define environ (*_NSGetEnviron())
  87 #else
  88 static char *mono_environ[1] = { NULL };
  89 #define environ mono_environ
  90 #endif /* defined (TARGET_OSX) */
  91 #elif defined(_MSC_VER)
  92 /* MS defines this in stdlib.h */
  93 #else
  94 G_BEGIN_DECLS
  95 extern char **environ;
  96 G_END_DECLS
  97 #endif
  98
  99 #if !defined (G_OS_WIN32) && defined (HAVE_FORK) && defined (HAVE_EXECV)
 100 static int
 101 safe_read (int fd, gchar *buffer, gint count, GError **gerror)
 102 {
 103         int res;
 104
 105         NO_INTR (res, read (fd, buffer, count));
 106         set_error_cond (res == -1, "%s", "Error reading from pipe.");
 107         return res;
 108 }
 109
 110 static int
 111 read_pipes (int outfd, gchar **out_str, int errfd, gchar **err_str, GError **gerror)
 112 {
 113         fd_set rfds;
 114         int res;
 115         gboolean out_closed;
 116         gboolean err_closed;
 117         GString *out = NULL;
 118         GString *err = NULL;
 119         gchar *buffer = NULL;
 120         gint nread;
 121
 122         out_closed = (outfd < 0);
 123         err_closed = (errfd < 0);
 124         if (out_str) {
 125                 *out_str = NULL;
 126                 out = g_string_new ("");
 127         }
 128
 129         if (err_str) {
 130                 *err_str = NULL;
 131                 err = g_string_new ("");
 132         }
 133
 134         do {
 135                 if (out_closed && err_closed)
 136                         break;
 137
 138                 FD_ZERO (&rfds);
 139                 if (!out_closed && outfd >= 0)
 140                         FD_SET (outfd, &rfds);
 141                 if (!err_closed && errfd >= 0)
 142                         FD_SET (errfd, &rfds);
 143
 144                 res = select (MAX (outfd, errfd) + 1, &rfds, NULL, NULL, NULL);
 145                 if (res > 0) {
 146                         if (buffer == NULL)
 147                                 buffer = g_malloc (1024);
 148                         if (!out_closed && FD_ISSET (outfd, &rfds)) {
 149                                 nread = safe_read (outfd, buffer, 1024, gerror);
 150                                 if (nread < 0) {
 151                                         close (errfd);
 152                                         close (outfd);
 153                                         return -1;
 154                                 }
 155                                 g_string_append_len (out, buffer, nread);
 156                                 if (nread <= 0) {
 157                                         out_closed = TRUE;
 158                                         close (outfd);
 159                                 }
 160                         }
 161
 162                         if (!err_closed && FD_ISSET (errfd, &rfds)) {
 163                                 nread = safe_read (errfd, buffer, 1024, gerror);
 164                                 if (nread < 0) {
 165                                         close (errfd);
 166                                         close (outfd);
 167                                         return -1;
 168                                 }
 169                                 g_string_append_len (err, buffer, nread);
 170                                 if (nread <= 0) {
 171                                         err_closed = TRUE;
 172                                         close (errfd);
 173                                 }
 174                         }
 175                 }
 176         } while (res > 0 || (res == -1 && errno == EINTR));
 177
 178         g_free (buffer);
 179         if (out_str)
 180                 *out_str = g_string_free (out, FALSE);
 181
 182         if (err_str)
 183                 *err_str = g_string_free (err, FALSE);
 184
 185         return 0;
 186 }
 187
 188 static gboolean
 189 create_pipe (int *fds, GError **gerror)
 190 {
 191         if (pipe (fds) == -1) {
 192                 set_error ("%s", "Error creating pipe.");
 193                 return FALSE;
 194         }
 195         return TRUE;
 196 }
 197
 198 static int
 199 write_all (int fd, const void *vbuf, size_t n)
 200 {
 201         const char *buf = (const char *) vbuf;
 202         size_t nwritten = 0;
 203         int w;
 204
 205         do {
 206                 do {
 207                         w = write (fd, buf + nwritten, n - nwritten);
 208                 } while (w == -1 && errno == EINTR);
 209
 210                 if (w == -1)
 211                         return -1;
 212
 213                 nwritten += w;
 214         } while (nwritten < n);
 215
 216         return nwritten;
 217 }
 218 #endif /* !defined (G_OS_WIN32) && defined (HAVE_FORK) && defined (HAVE_EXECV) */
 219
 220 #if !defined(G_OS_WIN32) && defined(HAVE_GETDTABLESIZE)
 221 int
 222 eg_getdtablesize (void)
 223 {
 224 #ifdef HAVE_GETRLIMIT
 225         struct rlimit limit;
 226         int res;
 227
 228         res = getrlimit (RLIMIT_NOFILE, &limit);
 229         g_assert (res == 0);
 230         return limit.rlim_cur;
 231 #else
 232         return getdtablesize ();
 233 #endif
 234 }
 235 #else
 236 int
 237 eg_getdtablesize (void)
 238 {
 239         g_error ("Should not be called");
 240 }
 241 #endif
 242
 243 gboolean
 244 g_spawn_command_line_sync (const gchar *command_line,
 245                                 gchar **standard_output,
 246                                 gchar **standard_error,
 247                                 gint *exit_status,
 248                                 GError **gerror)
 249 {
 250 #ifdef G_OS_WIN32
 251         return TRUE;
 252 #elif !defined (HAVE_FORK) || !defined (HAVE_EXECV)
 253         fprintf (stderr, "g_spawn_command_line_sync not supported on this platform\n");
 254         return FALSE;
 255 #else
 256         pid_t pid;
 257         gchar **argv;
 258         gint argc;
 259         int stdout_pipe [2] = { -1, -1 };
 260         int stderr_pipe [2] = { -1, -1 };
 261         int status;
 262         int res;
 263
 264         if (!g_shell_parse_argv (command_line, &argc, &argv, gerror))
 265                 return FALSE;
 266
 267         if (standard_output && !create_pipe (stdout_pipe, gerror))
 268                 return FALSE;
 269
 270         if (standard_error && !create_pipe (stderr_pipe, gerror)) {
 271                 if (standard_output) {
 272                         CLOSE_PIPE (stdout_pipe);
 273                 }
 274                 return FALSE;
 275         }
 276
 277         pid = fork ();
 278         if (pid == 0) {
 279                 gint i;
 280
 281                 if (standard_output) {
 282                         close (stdout_pipe [0]);
 283                         dup2 (stdout_pipe [1], STDOUT_FILENO);
 284                 }
 285
 286                 if (standard_error) {
 287                         close (stderr_pipe [0]);
 288                         dup2 (stderr_pipe [1], STDERR_FILENO);
 289                 }
 290                 for (i = eg_getdtablesize () - 1; i >= 3; i--)
 291                         close (i);
 292
 293                 /* G_SPAWN_SEARCH_PATH is always enabled for g_spawn_command_line_sync */
 294                 if (!g_path_is_absolute (argv [0])) {
 295                         gchar *arg0;
 296
 297                         arg0 = g_find_program_in_path (argv [0]);
 298                         if (arg0 == NULL) {
 299                                 exit (1);
 300                         }
 301                         //g_free (argv [0]);
 302                         argv [0] = arg0;
 303                 }
 304                 execv (argv [0], argv);
 305                 exit (1); /* TODO: What now? */
 306         }
 307
 308         g_strfreev (argv);
 309         if (standard_output)
 310                 close (stdout_pipe [1]);
 311
 312         if (standard_error)
 313                 close (stderr_pipe [1]);
 314
 315         if (standard_output || standard_error) {
 316                 res = read_pipes (stdout_pipe [0], standard_output, stderr_pipe [0], standard_error, gerror);
 317                 if (res) {
 318                         waitpid (pid, &status, WNOHANG); /* avoid zombie */
 319                         return FALSE;
 320                 }
 321         }
 322
 323         NO_INTR (res, waitpid (pid, &status, 0));
 324
 325         /* TODO: What if error? */
 326         if (WIFEXITED (status) && exit_status) {
 327                 *exit_status = WEXITSTATUS (status);
 328         }
 329         return TRUE;
 330 #endif
 331 }
 332
 333 /*
 334  * This is the only use we have in mono/metadata
 335 !g_spawn_async_with_pipes (NULL, (char**)addr_argv, NULL, G_SPAWN_SEARCH_PATH, NULL, NULL, &child_pid, &ch_in, &ch_out, NULL, NULL)
 336 */
 337 gboolean
 338 g_spawn_async_with_pipes (const gchar *working_directory,
 339                         gchar **argv,
 340                         gchar **envp,
 341                         GSpawnFlags flags,
 342                         GSpawnChildSetupFunc child_setup,
 343                         gpointer user_data,
 344                         GPid *child_pid,
 345                         gint *standard_input,
 346                         gint *standard_output,
 347                         gint *standard_error,
 348                         GError **gerror)
 349 {
 350 #ifdef G_OS_WIN32
 351         return TRUE;
 352 #elif !defined (HAVE_FORK) || !defined (HAVE_EXECVE)
 353         fprintf (stderr, "g_spawn_async_with_pipes is not supported on this platform\n");
 354         return FALSE;
 355 #else
 356         pid_t pid;
 357         int info_pipe [2];
 358         int in_pipe [2] = { -1, -1 };
 359         int out_pipe [2] = { -1, -1 };
 360         int err_pipe [2] = { -1, -1 };
 361         int status;
 362
 363         g_return_val_if_fail (argv != NULL, FALSE); /* Only mandatory arg */
 364
 365         if (!create_pipe (info_pipe, gerror))
 366                 return FALSE;
 367
 368         if (standard_output && !create_pipe (out_pipe, gerror)) {
 369                 CLOSE_PIPE (info_pipe);
 370                 return FALSE;
 371         }
 372
 373         if (standard_error && !create_pipe (err_pipe, gerror)) {
 374                 CLOSE_PIPE (info_pipe);
 375                 CLOSE_PIPE (out_pipe);
 376                 return FALSE;
 377         }
 378
 379         if (standard_input && !create_pipe (in_pipe, gerror)) {
 380                 CLOSE_PIPE (info_pipe);
 381                 CLOSE_PIPE (out_pipe);
 382                 CLOSE_PIPE (err_pipe);
 383                 return FALSE;
 384         }
 385
 386         pid = fork ();
 387         if (pid == -1) {
 388                 CLOSE_PIPE (info_pipe);
 389                 CLOSE_PIPE (out_pipe);
 390                 CLOSE_PIPE (err_pipe);
 391                 CLOSE_PIPE (in_pipe);
 392                 set_error ("%s", "Error in fork ()");
 393                 return FALSE;
 394         }
 395
 396         if (pid == 0) {
 397                 /* No zombie left behind */
 398                 if ((flags & G_SPAWN_DO_NOT_REAP_CHILD) == 0) {
 399                         pid = fork ();
 400                 }
 401
 402                 if (pid != 0) {
 403                         exit (pid == -1 ? 1 : 0);
 404                 }  else {
 405                         gint i;
 406                         int fd;
 407                         gchar *arg0;
 408                         gchar **actual_args;
 409                         gint unused;
 410
 411                         close (info_pipe [0]);
 412                         close (in_pipe [1]);
 413                         close (out_pipe [0]);
 414                         close (err_pipe [0]);
 415
 416                         /* when exec* succeeds, we want to close this fd, which will return
 417                          * a 0 read on the parent. We're not supposed to keep it open forever.
 418                          * If exec fails, we still can write the error to it before closing.
 419                          */
 420                         fcntl (info_pipe [1], F_SETFD, FD_CLOEXEC);
 421
 422                         if ((flags & G_SPAWN_DO_NOT_REAP_CHILD) == 0) {
 423                                 pid = getpid ();
 424                                 NO_INTR (unused, write_all (info_pipe [1], &pid, sizeof (pid_t)));
 425                         }
 426
 427                         if (working_directory && chdir (working_directory) == -1) {
 428                                 int err = errno;
 429                                 NO_INTR (unused, write_all (info_pipe [1], &err, sizeof (int)));
 430                                 exit (0);
 431                         }
 432
 433                         if (standard_output) {
 434                                 dup2 (out_pipe [1], STDOUT_FILENO);
 435                         } else if ((flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0) {
 436                                 fd = open ("/dev/null", O_WRONLY);
 437                                 dup2 (fd, STDOUT_FILENO);
 438                         }
 439
 440                         if (standard_error) {
 441                                 dup2 (err_pipe [1], STDERR_FILENO);
 442                         } else if ((flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0) {
 443                                 fd = open ("/dev/null", O_WRONLY);
 444                                 dup2 (fd, STDERR_FILENO);
 445                         }
 446
 447                         if (standard_input) {
 448                                 dup2 (in_pipe [0], STDIN_FILENO);
 449                         } else if ((flags & G_SPAWN_CHILD_INHERITS_STDIN) == 0) {
 450                                 fd = open ("/dev/null", O_RDONLY);
 451                                 dup2 (fd, STDIN_FILENO);
 452                         }
 453
 454                         if ((flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN) != 0) {
 455                                 for (i = eg_getdtablesize () - 1; i >= 3; i--)
 456                                         close (i);
 457                         }
 458
 459                         actual_args = ((flags & G_SPAWN_FILE_AND_ARGV_ZERO) == 0) ? argv : argv + 1;
 460                         if (envp == NULL)
 461                                 envp = environ;
 462
 463                         if (child_setup)
 464                                 child_setup (user_data);
 465
 466                         arg0 = argv [0];
 467                         if (!g_path_is_absolute (arg0) || (flags & G_SPAWN_SEARCH_PATH) != 0) {
 468                                 arg0 = g_find_program_in_path (argv [0]);
 469                                 if (arg0 == NULL) {
 470                                         int err = ENOENT;
 471                                         write_all (info_pipe [1], &err, sizeof (int));
 472                                         exit (0);
 473                                 }
 474                         }
 475
 476                         execve (arg0, actual_args, envp);
 477                         int const err = errno;
 478                         write_all (info_pipe [1], &err, sizeof (int));
 479                         exit (0);
 480                 }
 481         } else if ((flags & G_SPAWN_DO_NOT_REAP_CHILD) == 0) {
 482                 int w;
 483                 /* Wait for the first child if two are created */
 484                 NO_INTR (w, waitpid (pid, &status, 0));
 485                 if (status == 1 || w == -1) {
 486                         CLOSE_PIPE (info_pipe);
 487                         CLOSE_PIPE (out_pipe);
 488                         CLOSE_PIPE (err_pipe);
 489                         CLOSE_PIPE (in_pipe);
 490                         set_error ("Error in fork (): %d", status);
 491                         return FALSE;
 492                 }
 493         }
 494         close (info_pipe [1]);
 495         close (in_pipe [0]);
 496         close (out_pipe [1]);
 497         close (err_pipe [1]);
 498
 499         if ((flags & G_SPAWN_DO_NOT_REAP_CHILD) == 0) {
 500                 int x;
 501                 NO_INTR (x, read (info_pipe [0], &pid, sizeof (pid_t))); /* if we read < sizeof (pid_t)... */
 502         }
 503
 504         if (child_pid) {
 505                 *child_pid = pid;
 506         }
 507
 508         if (read (info_pipe [0], &status, sizeof (int)) != 0) {
 509                 close (info_pipe [0]);
 510                 close (in_pipe [0]);
 511                 close (out_pipe [1]);
 512                 close (err_pipe [1]);
 513                 set_error_status (status, "Error in exec (%d -> %s)", status, strerror (status));
 514                 return FALSE;
 515         }
 516
 517         close (info_pipe [0]);
 518         if (standard_input)
 519                 *standard_input = in_pipe [1];
 520         if (standard_output)
 521                 *standard_output = out_pipe [0];
 522         if (standard_error)
 523                 *standard_error = err_pipe [0];
 524         return TRUE;
 525 #endif
 526 }