eglib/src/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 #define __USE_GNU
  39 #include <unistd.h>
  40 #endif
  41
  42 #ifdef HAVE_SYS_TIME_H
  43 #include <sys/time.h>
  44 #endif
  45
  46 #ifdef HAVE_SYS_WAIT_H
  47 #include <sys/wait.h>
  48 #endif
  49
  50 #ifdef G_OS_WIN32
  51 #include <io.h>
  52 #include <winsock2.h>
  53 #define open _open
  54 #define close _close
  55 #define read _read
  56 #define write _write
  57 /* windows pipe api details: http://msdn2.microsoft.com/en-us/library/edze9h7e(VS.80).aspx */
  58 #define pipe(x) _pipe(x, 256, 0)
  59 #endif
  60
  61 #define set_error(msg, ...) do { if (error != NULL) *error = g_error_new (G_LOG_DOMAIN, 1, msg, __VA_ARGS__); } while (0)
  62 #define set_error_cond(cond,msg, ...) do { if ((cond) && error != NULL) *error = g_error_new (G_LOG_DOMAIN, 1, msg, __VA_ARGS__); } while (0)
  63 #define set_error_status(status,msg, ...) do { if (error != NULL) *error = g_error_new (G_LOG_DOMAIN, status, msg, __VA_ARGS__); } while (0)
  64 #define NO_INTR(var,cmd) do { (var) = (cmd); } while ((var) == -1 && errno == EINTR)
  65 #define CLOSE_PIPE(p) do { close (p [0]); close (p [1]); } while (0)
  66
  67 #ifdef __APPLE__
  68 /* Apple defines this in crt_externs.h but doesn't provide that header for
  69  * arm-apple-darwin9.  We'll manually define the symbol on Apple as it does
  70  * in fact exist on all implementations (so far)
  71  */
  72 gchar ***_NSGetEnviron();
  73 #define environ (*_NSGetEnviron())
  74 #endif
  75
  76 static int
  77 safe_read (int fd, gchar *buffer, gint count, GError **error)
  78 {
  79         int res;
  80
  81         NO_INTR (res, read (fd, buffer, count));
  82         set_error_cond (res == -1, "%s", "Error reading from pipe.");
  83         return res;
  84 }
  85
  86 static int
  87 read_pipes (int outfd, gchar **out_str, int errfd, gchar **err_str, GError **error)
  88 {
  89         fd_set rfds;
  90         int res;
  91         gboolean out_closed;
  92         gboolean err_closed;
  93         GString *out = NULL;
  94         GString *err = NULL;
  95         gchar *buffer = NULL;
  96         gint nread;
  97
  98         out_closed = (outfd < 0);
  99         err_closed = (errfd < 0);
 100         if (out_str) {
 101                 *out_str = NULL;
 102                 out = g_string_new ("");
 103         }
 104
 105         if (err_str) {
 106                 *err_str = NULL;
 107                 err = g_string_new ("");
 108         }
 109
 110         do {
 111                 if (out_closed && err_closed)
 112                         break;
 113
 114 #ifdef _MSC_VER
 115 #pragma warning(push)
 116 #pragma warning(disable:4389)
 117 #endif
 118
 119                 FD_ZERO (&rfds);
 120                 if (!out_closed && outfd >= 0)
 121                         FD_SET (outfd, &rfds);
 122                 if (!err_closed && errfd >= 0)
 123                         FD_SET (errfd, &rfds);
 124
 125 #ifdef _MSC_VER
 126 #pragma warning(pop)
 127 #endif
 128
 129                 res = select (MAX (outfd, errfd) + 1, &rfds, NULL, NULL, NULL);
 130                 if (res > 0) {
 131                         if (buffer == NULL)
 132                                 buffer = g_malloc (1024);
 133                         if (!out_closed && FD_ISSET (outfd, &rfds)) {
 134                                 nread = safe_read (outfd, buffer, 1024, error);
 135                                 if (nread < 0) {
 136                                         close (errfd);
 137                                         close (outfd);
 138                                         return -1;
 139                                 }
 140                                 g_string_append_len (out, buffer, nread);
 141                                 if (nread <= 0) {
 142                                         out_closed = TRUE;
 143                                         close (outfd);
 144                                 }
 145                         }
 146
 147                         if (!err_closed && FD_ISSET (errfd, &rfds)) {
 148                                 nread = safe_read (errfd, buffer, 1024, error);
 149                                 if (nread < 0) {
 150                                         close (errfd);
 151                                         close (outfd);
 152                                         return -1;
 153                                 }
 154                                 g_string_append_len (err, buffer, nread);
 155                                 if (nread <= 0) {
 156                                         err_closed = TRUE;
 157                                         close (errfd);
 158                                 }
 159                         }
 160                 }
 161         } while (res > 0 || (res == -1 && errno == EINTR));
 162
 163         g_free (buffer);
 164         if (out_str)
 165                 *out_str = g_string_free (out, FALSE);
 166
 167         if (err_str)
 168                 *err_str = g_string_free (err, FALSE);
 169
 170         return 0;
 171 }
 172
 173 static gboolean
 174 create_pipe (int *fds, GError **error)
 175 {
 176         if (pipe (fds) == -1) {
 177                 set_error ("%s", "Error creating pipe.");
 178                 return FALSE;
 179         }
 180         return TRUE;
 181 }
 182
 183 gboolean
 184 g_spawn_command_line_sync (const gchar *command_line,
 185                                 gchar **standard_output,
 186                                 gchar **standard_error,
 187                                 gint *exit_status,
 188                                 GError **error)
 189 {
 190 #ifdef G_OS_WIN32
 191 #else
 192         pid_t pid;
 193         gchar **argv;
 194         gint argc;
 195         int stdout_pipe [2] = { -1, -1 };
 196         int stderr_pipe [2] = { -1, -1 };
 197         int status;
 198         int res;
 199
 200         if (!g_shell_parse_argv (command_line, &argc, &argv, error))
 201                 return FALSE;
 202
 203         if (standard_output && !create_pipe (stdout_pipe, error))
 204                 return FALSE;
 205
 206         if (standard_error && !create_pipe (stderr_pipe, error)) {
 207                 if (standard_output) {
 208                         CLOSE_PIPE (stdout_pipe);
 209                 }
 210                 return FALSE;
 211         }
 212
 213         pid = fork ();
 214         if (pid == 0) {
 215                 gint i;
 216
 217                 if (standard_output) {
 218                         close (stdout_pipe [0]);
 219                         dup2 (stdout_pipe [1], STDOUT_FILENO);
 220                 }
 221
 222                 if (standard_error) {
 223                         close (stderr_pipe [0]);
 224                         dup2 (stderr_pipe [1], STDERR_FILENO);
 225                 }
 226                 for (i = getdtablesize () - 1; i >= 3; i--)
 227                         close (i);
 228
 229                 /* G_SPAWN_SEARCH_PATH is always enabled for g_spawn_command_line_sync */
 230                 if (!g_path_is_absolute (argv [0])) {
 231                         gchar *arg0;
 232
 233                         arg0 = g_find_program_in_path (argv [0]);
 234                         if (arg0 == NULL) {
 235                                 exit (1);
 236                         }
 237                         //g_free (argv [0]);
 238                         argv [0] = arg0;
 239                 }
 240                 execv (argv [0], argv);
 241                 exit (1); /* TODO: What now? */
 242         }
 243
 244         g_strfreev (argv);
 245         if (standard_output)
 246                 close (stdout_pipe [1]);
 247
 248         if (standard_error)
 249                 close (stderr_pipe [1]);
 250
 251         if (standard_output || standard_error) {
 252                 res = read_pipes (stdout_pipe [0], standard_output, stderr_pipe [0], standard_error, error);
 253                 if (res) {
 254                         waitpid (pid, &status, WNOHANG); /* avoid zombie */
 255                         return FALSE;
 256                 }
 257         }
 258
 259         NO_INTR (res, waitpid (pid, &status, 0));
 260
 261         /* TODO: What if error? */
 262         if (WIFEXITED (status) && exit_status) {
 263                 *exit_status = WEXITSTATUS (status);
 264         }
 265 #endif
 266         return TRUE;
 267 }
 268
 269 /*
 270  * This is the only use we have in mono/metadata
 271 !g_spawn_async_with_pipes (NULL, (char**)addr_argv, NULL, G_SPAWN_SEARCH_PATH, NULL, NULL, &child_pid, &ch_in, &ch_out, NULL, NULL)
 272 */
 273 gboolean
 274 g_spawn_async_with_pipes (const gchar *working_directory,
 275                         gchar **argv,
 276                         gchar **envp,
 277                         GSpawnFlags flags,
 278                         GSpawnChildSetupFunc child_setup,
 279                         gpointer user_data,
 280                         GPid *child_pid,
 281                         gint *standard_input,
 282                         gint *standard_output,
 283                         gint *standard_error,
 284                         GError **error)
 285 {
 286 #ifdef G_OS_WIN32
 287 #else
 288         pid_t pid;
 289         int info_pipe [2];
 290         int in_pipe [2] = { -1, -1 };
 291         int out_pipe [2] = { -1, -1 };
 292         int err_pipe [2] = { -1, -1 };
 293         int status;
 294
 295         g_return_val_if_fail (argv != NULL, FALSE); /* Only mandatory arg */
 296
 297         if (!create_pipe (info_pipe, error))
 298                 return FALSE;
 299
 300         if (standard_output && !create_pipe (out_pipe, error)) {
 301                 CLOSE_PIPE (info_pipe);
 302                 return FALSE;
 303         }
 304
 305         if (standard_error && !create_pipe (err_pipe, error)) {
 306                 CLOSE_PIPE (info_pipe);
 307                 CLOSE_PIPE (out_pipe);
 308                 return FALSE;
 309         }
 310
 311         if (standard_input && !create_pipe (in_pipe, error)) {
 312                 CLOSE_PIPE (info_pipe);
 313                 CLOSE_PIPE (out_pipe);
 314                 CLOSE_PIPE (err_pipe);
 315                 return FALSE;
 316         }
 317
 318         pid = fork ();
 319         if (pid == -1) {
 320                 CLOSE_PIPE (info_pipe);
 321                 CLOSE_PIPE (out_pipe);
 322                 CLOSE_PIPE (err_pipe);
 323                 CLOSE_PIPE (in_pipe);
 324                 set_error ("%s", "Error in fork ()");
 325                 return FALSE;
 326         }
 327
 328         if (pid == 0) {
 329                 /* No zombie left behind */
 330                 if ((flags & G_SPAWN_DO_NOT_REAP_CHILD) == 0) {
 331                         pid = fork ();
 332                 }
 333
 334                 if (pid != 0) {
 335                         exit (pid == -1 ? 1 : 0);
 336                 }  else {
 337                         gint i;
 338                         int fd;
 339                         gchar *arg0;
 340                         gchar **actual_args;
 341                         gint unused;
 342
 343                         close (info_pipe [0]);
 344                         close (in_pipe [1]);
 345                         close (out_pipe [0]);
 346                         close (err_pipe [0]);
 347
 348                         /* when exec* succeeds, we want to close this fd, which will return
 349                          * a 0 read on the parent. We're not supposed to keep it open forever.
 350                          * If exec fails, we still can write the error to it before closing.
 351                          */
 352                         fcntl (info_pipe [1], F_SETFD, FD_CLOEXEC);
 353
 354                         if ((flags & G_SPAWN_DO_NOT_REAP_CHILD) == 0) {
 355                                 pid = getpid ();
 356                                 NO_INTR (unused, write (info_pipe [1], &pid, sizeof (pid_t)));
 357                         }
 358
 359                         if (working_directory && chdir (working_directory) == -1) {
 360                                 int err = errno;
 361                                 NO_INTR (unused, write (info_pipe [1], &err, sizeof (int)));
 362                                 exit (0);
 363                         }
 364
 365                         if (standard_output) {
 366                                 dup2 (out_pipe [1], STDOUT_FILENO);
 367                         } else if ((flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0) {
 368                                 fd = open ("/dev/null", O_WRONLY);
 369                                 dup2 (fd, STDOUT_FILENO);
 370                         }
 371
 372                         if (standard_error) {
 373                                 dup2 (err_pipe [1], STDERR_FILENO);
 374                         } else if ((flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0) {
 375                                 fd = open ("/dev/null", O_WRONLY);
 376                                 dup2 (fd, STDERR_FILENO);
 377                         }
 378
 379                         if (standard_input) {
 380                                 dup2 (in_pipe [0], STDERR_FILENO);
 381                         } else if ((flags & G_SPAWN_CHILD_INHERITS_STDIN) == 0) {
 382                                 fd = open ("/dev/null", O_RDONLY);
 383                                 dup2 (fd, STDERR_FILENO);
 384                         }
 385
 386                         if ((flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN) != 0) {
 387                                 for (i = getdtablesize () - 1; i >= 3; i--)
 388                                         close (i);
 389                         }
 390
 391                         actual_args = ((flags & G_SPAWN_FILE_AND_ARGV_ZERO) == 0) ? argv : argv + 1;
 392                         if (envp == NULL)
 393                                 envp = environ;
 394
 395                         if (child_setup)
 396                                 child_setup (user_data);
 397
 398                         arg0 = argv [0];
 399                         if (!g_path_is_absolute (arg0) || (flags & G_SPAWN_SEARCH_PATH) != 0) {
 400                                 arg0 = g_find_program_in_path (argv [0]);
 401                                 if (arg0 == NULL) {
 402                                         int err = ENOENT;
 403                                         write (info_pipe [1], &err, sizeof (int));
 404                                         exit (0);
 405                                 }
 406                         }
 407
 408                         execve (arg0, actual_args, envp);
 409                         write (info_pipe [1], &errno, sizeof (int));
 410                         exit (0);
 411                 }
 412         } else if ((flags & G_SPAWN_DO_NOT_REAP_CHILD) == 0) {
 413                 int w;
 414                 /* Wait for the first child if two are created */
 415                 NO_INTR (w, waitpid (pid, &status, 0));
 416                 if (status == 1 || w == -1) {
 417                         CLOSE_PIPE (info_pipe);
 418                         CLOSE_PIPE (out_pipe);
 419                         CLOSE_PIPE (err_pipe);
 420                         CLOSE_PIPE (in_pipe);
 421                         set_error ("Error in fork (): %d", status);
 422                         return FALSE;
 423                 }
 424         }
 425         close (info_pipe [1]);
 426         close (in_pipe [0]);
 427         close (out_pipe [1]);
 428         close (err_pipe [1]);
 429
 430         if ((flags & G_SPAWN_DO_NOT_REAP_CHILD) == 0) {
 431                 int x;
 432                 NO_INTR (x, read (info_pipe [0], &pid, sizeof (pid_t))); /* if we read < sizeof (pid_t)... */
 433         }
 434
 435         if (child_pid) {
 436                 *child_pid = pid;
 437         }
 438
 439         if (read (info_pipe [0], &status, sizeof (int)) != 0) {
 440                 close (info_pipe [0]);
 441                 close (in_pipe [0]);
 442                 close (out_pipe [1]);
 443                 close (err_pipe [1]);
 444                 set_error_status (status, "Error in exec (%d -> %s)", status, strerror (status));
 445                 return FALSE;
 446         }
 447
 448         close (info_pipe [0]);
 449         if (standard_input)
 450                 *standard_input = in_pipe [1];
 451         if (standard_output)
 452                 *standard_output = out_pipe [0];
 453         if (standard_error)
 454                 *standard_error = err_pipe [0];
 455 #endif
 456         return TRUE;
 457 }
 458
 459