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 (error != NULL) *error = g_error_new (G_LOG_DOMAIN, 1, msg, __VA_ARGS__); } while (0)
  72 #define set_error_cond(cond,msg, ...) do { if ((cond) && error != NULL) *error = g_error_new (G_LOG_DOMAIN, 1, msg, __VA_ARGS__); } while (0)
  73 #define set_error_status(status,msg, ...) do { if (error != NULL) *error = 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 gchar ***_NSGetEnviron(void);
  84 #define environ (*_NSGetEnviron())
  85 #else
  86 static char *mono_environ[1] = { NULL };
  87 #define environ mono_environ
  88 #endif /* defined (TARGET_OSX) */
  89 #elif defined(_MSC_VER)
  90 /* MS defines this in stdlib.h */
  91 #else
  92 extern char **environ;
  93 #endif
  94
  95 #ifndef G_OS_WIN32
  96 static int
  97 safe_read (int fd, gchar *buffer, gint count, GError **error)
  98 {
  99         int res;
 100
 101         NO_INTR (res, read (fd, buffer, count));
 102         set_error_cond (res == -1, "%s", "Error reading from pipe.");
 103         return res;
 104 }
 105
 106 static int
 107 read_pipes (int outfd, gchar **out_str, int errfd, gchar **err_str, GError **error)
 108 {
 109         fd_set rfds;
 110         int res;
 111         gboolean out_closed;
 112         gboolean err_closed;
 113         GString *out = NULL;
 114         GString *err = NULL;
 115         gchar *buffer = NULL;
 116         gint nread;
 117
 118         out_closed = (outfd < 0);
 119         err_closed = (errfd < 0);
 120         if (out_str) {
 121                 *out_str = NULL;
 122                 out = g_string_new ("");
 123         }
 124
 125         if (err_str) {
 126                 *err_str = NULL;
 127                 err = g_string_new ("");
 128         }
 129
 130         do {
 131                 if (out_closed && err_closed)
 132                         break;
 133
 134 #ifdef _MSC_VER
 135 #pragma warning(push)
 136 #pragma warning(disable:4389)
 137 #endif
 138
 139                 FD_ZERO (&rfds);
 140                 if (!out_closed && outfd >= 0)
 141                         FD_SET (outfd, &rfds);
 142                 if (!err_closed && errfd >= 0)
 143                         FD_SET (errfd, &rfds);
 144
 145 #ifdef _MSC_VER
 146 #pragma warning(pop)
 147 #endif
 148
 149                 res = select (MAX (outfd, errfd) + 1, &rfds, NULL, NULL, NULL);
 150                 if (res > 0) {
 151                         if (buffer == NULL)
 152                                 buffer = g_malloc (1024);
 153                         if (!out_closed && FD_ISSET (outfd, &rfds)) {
 154                                 nread = safe_read (outfd, buffer, 1024, error);
 155                                 if (nread < 0) {
 156                                         close (errfd);
 157                                         close (outfd);
 158                                         return -1;
 159                                 }
 160                                 g_string_append_len (out, buffer, nread);
 161                                 if (nread <= 0) {
 162                                         out_closed = TRUE;
 163                                         close (outfd);
 164                                 }
 165                         }
 166
 167                         if (!err_closed && FD_ISSET (errfd, &rfds)) {
 168                                 nread = safe_read (errfd, buffer, 1024, error);
 169                                 if (nread < 0) {
 170                                         close (errfd);
 171                                         close (outfd);
 172                                         return -1;
 173                                 }
 174                                 g_string_append_len (err, buffer, nread);
 175                                 if (nread <= 0) {
 176                                         err_closed = TRUE;
 177                                         close (errfd);
 178                                 }
 179                         }
 180                 }
 181         } while (res > 0 || (res == -1 && errno == EINTR));
 182
 183         g_free (buffer);
 184         if (out_str)
 185                 *out_str = g_string_free (out, FALSE);
 186
 187         if (err_str)
 188                 *err_str = g_string_free (err, FALSE);
 189
 190         return 0;
 191 }
 192
 193 static gboolean
 194 create_pipe (int *fds, GError **error)
 195 {
 196         if (pipe (fds) == -1) {
 197                 set_error ("%s", "Error creating pipe.");
 198                 return FALSE;
 199         }
 200         return TRUE;
 201 }
 202 #endif /* G_OS_WIN32 */
 203
 204 static int
 205 write_all (int fd, const void *vbuf, size_t n)
 206 {
 207         const char *buf = (const char *) vbuf;
 208         size_t nwritten = 0;
 209         int w;
 210
 211         do {
 212                 do {
 213                         w = write (fd, buf + nwritten, n - nwritten);
 214                 } while (w == -1 && errno == EINTR);
 215
 216                 if (w == -1)
 217                         return -1;
 218
 219                 nwritten += w;
 220         } while (nwritten < n);
 221
 222         return nwritten;
 223 }
 224
 225 #ifndef G_OS_WIN32
 226 int
 227 eg_getdtablesize (void)
 228 {
 229 #ifdef HAVE_GETRLIMIT
 230         struct rlimit limit;
 231         int res;
 232
 233         res = getrlimit (RLIMIT_NOFILE, &limit);
 234         g_assert (res == 0);
 235         return limit.rlim_cur;
 236 #else
 237         return getdtablesize ();
 238 #endif
 239 }
 240 #else
 241 int
 242 eg_getdtablesize (void)
 243 {
 244         g_error ("Should not be called");
 245 }
 246 #endif
 247
 248 gboolean
 249 g_spawn_command_line_sync (const gchar *command_line,
 250                                 gchar **standard_output,
 251                                 gchar **standard_error,
 252                                 gint *exit_status,
 253                                 GError **error)
 254 {
 255 #ifdef G_OS_WIN32
 256 #elif !defined (HAVE_FORK) || !defined (HAVE_EXECV)
 257         fprintf (stderr, "g_spawn_command_line_sync not supported on this platform\n");
 258         return FALSE;
 259 #else
 260         pid_t pid;
 261         gchar **argv;
 262         gint argc;
 263         int stdout_pipe [2] = { -1, -1 };
 264         int stderr_pipe [2] = { -1, -1 };
 265         int status;
 266         int res;
 267
 268         if (!g_shell_parse_argv (command_line, &argc, &argv, error))
 269                 return FALSE;
 270
 271         if (standard_output && !create_pipe (stdout_pipe, error))
 272                 return FALSE;
 273
 274         if (standard_error && !create_pipe (stderr_pipe, error)) {
 275                 if (standard_output) {
 276                         CLOSE_PIPE (stdout_pipe);
 277                 }
 278                 return FALSE;
 279         }
 280
 281         pid = fork ();
 282         if (pid == 0) {
 283                 gint i;
 284
 285                 if (standard_output) {
 286                         close (stdout_pipe [0]);
 287                         dup2 (stdout_pipe [1], STDOUT_FILENO);
 288                 }
 289
 290                 if (standard_error) {
 291                         close (stderr_pipe [0]);
 292                         dup2 (stderr_pipe [1], STDERR_FILENO);
 293                 }
 294                 for (i = eg_getdtablesize () - 1; i >= 3; i--)
 295                         close (i);
 296
 297                 /* G_SPAWN_SEARCH_PATH is always enabled for g_spawn_command_line_sync */
 298                 if (!g_path_is_absolute (argv [0])) {
 299                         gchar *arg0;
 300
 301                         arg0 = g_find_program_in_path (argv [0]);
 302                         if (arg0 == NULL) {
 303                                 exit (1);
 304                         }
 305                         //g_free (argv [0]);
 306                         argv [0] = arg0;
 307                 }
 308                 execv (argv [0], argv);
 309                 exit (1); /* TODO: What now? */
 310         }
 311
 312         g_strfreev (argv);
 313         if (standard_output)
 314                 close (stdout_pipe [1]);
 315
 316         if (standard_error)
 317                 close (stderr_pipe [1]);
 318
 319         if (standard_output || standard_error) {
 320                 res = read_pipes (stdout_pipe [0], standard_output, stderr_pipe [0], standard_error, error);
 321                 if (res) {
 322                         waitpid (pid, &status, WNOHANG); /* avoid zombie */
 323                         return FALSE;
 324                 }
 325         }
 326
 327         NO_INTR (res, waitpid (pid, &status, 0));
 328
 329         /* TODO: What if error? */
 330         if (WIFEXITED (status) && exit_status) {
 331                 *exit_status = WEXITSTATUS (status);
 332         }
 333 #endif
 334         return TRUE;
 335 }
 336
 337 /*
 338  * This is the only use we have in mono/metadata
 339 !g_spawn_async_with_pipes (NULL, (char**)addr_argv, NULL, G_SPAWN_SEARCH_PATH, NULL, NULL, &child_pid, &ch_in, &ch_out, NULL, NULL)
 340 */
 341 gboolean
 342 g_spawn_async_with_pipes (const gchar *working_directory,
 343                         gchar **argv,
 344                         gchar **envp,
 345                         GSpawnFlags flags,
 346                         GSpawnChildSetupFunc child_setup,
 347                         gpointer user_data,
 348                         GPid *child_pid,
 349                         gint *standard_input,
 350                         gint *standard_output,
 351                         gint *standard_error,
 352                         GError **error)
 353 {
 354 #ifdef G_OS_WIN32
 355 #elif !defined (HAVE_FORK) || !defined (HAVE_EXECVE)
 356         fprintf (stderr, "g_spawn_async_with_pipes is not supported on this platform\n");
 357         return FALSE;
 358 #else
 359         pid_t pid;
 360         int info_pipe [2];
 361         int in_pipe [2] = { -1, -1 };
 362         int out_pipe [2] = { -1, -1 };
 363         int err_pipe [2] = { -1, -1 };
 364         int status;
 365
 366         g_return_val_if_fail (argv != NULL, FALSE); /* Only mandatory arg */
 367
 368         if (!create_pipe (info_pipe, error))
 369                 return FALSE;
 370
 371         if (standard_output && !create_pipe (out_pipe, error)) {
 372                 CLOSE_PIPE (info_pipe);
 373                 return FALSE;
 374         }
 375
 376         if (standard_error && !create_pipe (err_pipe, error)) {
 377                 CLOSE_PIPE (info_pipe);
 378                 CLOSE_PIPE (out_pipe);
 379                 return FALSE;
 380         }
 381
 382         if (standard_input && !create_pipe (in_pipe, error)) {
 383                 CLOSE_PIPE (info_pipe);
 384                 CLOSE_PIPE (out_pipe);
 385                 CLOSE_PIPE (err_pipe);
 386                 return FALSE;
 387         }
 388
 389         pid = fork ();
 390         if (pid == -1) {
 391                 CLOSE_PIPE (info_pipe);
 392                 CLOSE_PIPE (out_pipe);
 393                 CLOSE_PIPE (err_pipe);
 394                 CLOSE_PIPE (in_pipe);
 395                 set_error ("%s", "Error in fork ()");
 396                 return FALSE;
 397         }
 398
 399         if (pid == 0) {
 400                 /* No zombie left behind */
 401                 if ((flags & G_SPAWN_DO_NOT_REAP_CHILD) == 0) {
 402                         pid = fork ();
 403                 }
 404
 405                 if (pid != 0) {
 406                         exit (pid == -1 ? 1 : 0);
 407                 }  else {
 408                         gint i;
 409                         int fd;
 410                         gchar *arg0;
 411                         gchar **actual_args;
 412                         gint unused;
 413
 414                         close (info_pipe [0]);
 415                         close (in_pipe [1]);
 416                         close (out_pipe [0]);
 417                         close (err_pipe [0]);
 418
 419                         /* when exec* succeeds, we want to close this fd, which will return
 420                          * a 0 read on the parent. We're not supposed to keep it open forever.
 421                          * If exec fails, we still can write the error to it before closing.
 422                          */
 423                         fcntl (info_pipe [1], F_SETFD, FD_CLOEXEC);
 424
 425                         if ((flags & G_SPAWN_DO_NOT_REAP_CHILD) == 0) {
 426                                 pid = getpid ();
 427                                 NO_INTR (unused, write_all (info_pipe [1], &pid, sizeof (pid_t)));
 428                         }
 429
 430                         if (working_directory && chdir (working_directory) == -1) {
 431                                 int err = errno;
 432                                 NO_INTR (unused, write_all (info_pipe [1], &err, sizeof (int)));
 433                                 exit (0);
 434                         }
 435
 436                         if (standard_output) {
 437                                 dup2 (out_pipe [1], STDOUT_FILENO);
 438                         } else if ((flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0) {
 439                                 fd = open ("/dev/null", O_WRONLY);
 440                                 dup2 (fd, STDOUT_FILENO);
 441                         }
 442
 443                         if (standard_error) {
 444                                 dup2 (err_pipe [1], STDERR_FILENO);
 445                         } else if ((flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0) {
 446                                 fd = open ("/dev/null", O_WRONLY);
 447                                 dup2 (fd, STDERR_FILENO);
 448                         }
 449
 450                         if (standard_input) {
 451                                 dup2 (in_pipe [0], STDIN_FILENO);
 452                         } else if ((flags & G_SPAWN_CHILD_INHERITS_STDIN) == 0) {
 453                                 fd = open ("/dev/null", O_RDONLY);
 454                                 dup2 (fd, STDIN_FILENO);
 455                         }
 456
 457                         if ((flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN) != 0) {
 458                                 for (i = eg_getdtablesize () - 1; i >= 3; i--)
 459                                         close (i);
 460                         }
 461
 462                         actual_args = ((flags & G_SPAWN_FILE_AND_ARGV_ZERO) == 0) ? argv : argv + 1;
 463                         if (envp == NULL)
 464                                 envp = environ;
 465
 466                         if (child_setup)
 467                                 child_setup (user_data);
 468
 469                         arg0 = argv [0];
 470                         if (!g_path_is_absolute (arg0) || (flags & G_SPAWN_SEARCH_PATH) != 0) {
 471                                 arg0 = g_find_program_in_path (argv [0]);
 472                                 if (arg0 == NULL) {
 473                                         int err = ENOENT;
 474                                         write_all (info_pipe [1], &err, sizeof (int));
 475                                         exit (0);
 476                                 }
 477                         }
 478
 479                         execve (arg0, actual_args, envp);
 480                         write_all (info_pipe [1], &errno, sizeof (int));
 481                         exit (0);
 482                 }
 483         } else if ((flags & G_SPAWN_DO_NOT_REAP_CHILD) == 0) {
 484                 int w;
 485                 /* Wait for the first child if two are created */
 486                 NO_INTR (w, waitpid (pid, &status, 0));
 487                 if (status == 1 || w == -1) {
 488                         CLOSE_PIPE (info_pipe);
 489                         CLOSE_PIPE (out_pipe);
 490                         CLOSE_PIPE (err_pipe);
 491                         CLOSE_PIPE (in_pipe);
 492                         set_error ("Error in fork (): %d", status);
 493                         return FALSE;
 494                 }
 495         }
 496         close (info_pipe [1]);
 497         close (in_pipe [0]);
 498         close (out_pipe [1]);
 499         close (err_pipe [1]);
 500
 501         if ((flags & G_SPAWN_DO_NOT_REAP_CHILD) == 0) {
 502                 int x;
 503                 NO_INTR (x, read (info_pipe [0], &pid, sizeof (pid_t))); /* if we read < sizeof (pid_t)... */
 504         }
 505
 506         if (child_pid) {
 507                 *child_pid = pid;
 508         }
 509
 510         if (read (info_pipe [0], &status, sizeof (int)) != 0) {
 511                 close (info_pipe [0]);
 512                 close (in_pipe [0]);
 513                 close (out_pipe [1]);
 514                 close (err_pipe [1]);
 515                 set_error_status (status, "Error in exec (%d -> %s)", status, strerror (status));
 516                 return FALSE;
 517         }
 518
 519         close (info_pipe [0]);
 520         if (standard_input)
 521                 *standard_input = in_pipe [1];
 522         if (standard_output)
 523                 *standard_output = out_pipe [0];
 524         if (standard_error)
 525                 *standard_error = err_pipe [0];
 526 #endif
 527         return TRUE;
 528 }
 529
 530