X-Git-Url: https://git.dogcows.com/gitweb?p=chaz%2Ftar;a=blobdiff_plain;f=src%2Fsystem.c;h=94142336ef6d021868836cf94a97720ee9d20429;hp=fb5a8fa5a147e2040cfd99535ab5d5d6bf5eec30;hb=45ccda119355a1087450039a250359c1d0de0d08;hpb=8e3a2a520d68e31bf93a90f20bd0f19d83ae5cc6

diff --git a/src/system.c b/src/system.c
index fb5a8fa..9414233 100644
--- a/src/system.c
+++ b/src/system.c
@@ -1,6 +1,6 @@
 /* System-dependent calls for tar.
 
-   Copyright (C) 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+   Copyright 2003-2008, 2010, 2013-2014 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the
@@ -13,15 +13,28 @@
    Public License for more details.
 
    You should have received a copy of the GNU General Public License along
-   with this program; if not, write to the Free Software Foundation, Inc.,
-   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+   with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <system.h>
-#include <setenv.h>
 
 #include "common.h"
+#include <priv-set.h>
 #include <rmt.h>
 #include <signal.h>
+#include <wordsplit.h>
+
+static _Noreturn void
+xexec (const char *cmd)
+{
+  struct wordsplit ws;
+
+  ws.ws_env = (const char **) environ;
+  if (wordsplit (cmd, &ws, (WRDSF_DEFFLAGS | WRDSF_ENV) & ~WRDSF_NOVAR))
+    FATAL_ERROR ((0, 0, _("cannot split string '%s': %s"),
+		  cmd, wordsplit_strerror (&ws)));
+  execvp (ws.ws_wordv[0], ws.ws_wordv);
+  exec_fatal (cmd);
+}
 
 #if MSDOS
 
@@ -52,12 +65,7 @@ sys_detect_dev_null_output (void)
 }
 
 void
-sys_drain_input_pipe (void)
-{
-}
-
-void
-sys_wait_for_child (pid_t child_pid)
+sys_wait_for_child (pid_t child_pid, bool eof)
 {
 }
 
@@ -161,26 +169,8 @@ sys_detect_dev_null_output (void)
 			 && archive_stat.st_ino == dev_null_stat.st_ino));
 }
 
-/* Manage to fully drain a pipe we might be reading, so to not break it on
-   the producer after the EOF block.  FIXME: one of these days, GNU tar
-   might become clever enough to just stop working, once there is no more
-   work to do, we might have to revise this area in such time.  */
-
 void
-sys_drain_input_pipe (void)
-{
-  size_t r;
-
-  if (access_mode == ACCESS_READ
-      && ! _isrmt (archive)
-      && (S_ISFIFO (archive_stat.st_mode) || S_ISSOCK (archive_stat.st_mode)))
-    while ((r = rmtread (archive, record_start->buffer, record_size)) != 0
-	   && r != SAFE_READ_ERROR)
-      continue;
-}
-
-void
-sys_wait_for_child (pid_t child_pid)
+sys_wait_for_child (pid_t child_pid, bool eof)
 {
   if (child_pid)
     {
@@ -194,11 +184,14 @@ sys_wait_for_child (pid_t child_pid)
 	  }
 
       if (WIFSIGNALED (wait_status))
-	ERROR ((0, 0, _("Child died with signal %d"),
-		WTERMSIG (wait_status)));
+	{
+	  int sig = WTERMSIG (wait_status);
+	  if (!(!eof && sig == SIGPIPE))
+	    FATAL_ERROR ((0, 0, _("Child died with signal %d"), sig));
+	}
       else if (WEXITSTATUS (wait_status) != 0)
-	ERROR ((0, 0, _("Child returned status %d"),
-		WEXITSTATUS (wait_status)));
+	FATAL_ERROR ((0, 0, _("Child returned status %d"),
+		      WEXITSTATUS (wait_status)));
     }
 }
 
@@ -212,7 +205,8 @@ sys_spawn_shell (void)
   child = xfork ();
   if (child == 0)
     {
-      execlp (shell, "-sh", "-i", (char *) 0);
+      priv_set_restore_linkdir ();
+      execlp (shell, "-sh", "-i", NULL);
       exec_fatal (shell);
     }
   else
@@ -303,6 +297,30 @@ xdup2 (int from, int into)
     }
 }
 
+static void wait_for_grandchild (pid_t pid) __attribute__ ((__noreturn__));
+
+/* Propagate any failure of the grandchild back to the parent.  */
+static void
+wait_for_grandchild (pid_t pid)
+{
+  int wait_status;
+  int exit_code = 0;
+
+  while (waitpid (pid, &wait_status, 0) == -1)
+    if (errno != EINTR)
+      {
+	waitpid_error (use_compress_program_option);
+	break;
+      }
+
+  if (WIFSIGNALED (wait_status))
+    raise (WTERMSIG (wait_status));
+  else if (WEXITSTATUS (wait_status) != 0)
+    exit_code = WEXITSTATUS (wait_status);
+
+  exit (exit_code);
+}
+
 /* Set ARCHIVE for writing, then compressing an archive.  */
 pid_t
 sys_child_open_for_compress (void)
@@ -311,7 +329,6 @@ sys_child_open_for_compress (void)
   int child_pipe[2];
   pid_t grandchild_pid;
   pid_t child_pid;
-  int wait_status;
 
   xpipe (parent_pipe);
   child_pid = xfork ();
@@ -327,7 +344,8 @@ sys_child_open_for_compress (void)
 
   /* The new born child tar is here!  */
 
-  program_name = _("tar (child)");
+  set_program_name (_("tar (child)"));
+  signal (SIGPIPE, SIG_DFL);
 
   xdup2 (parent_pipe[PREAD], STDIN_FILENO);
   xclose (parent_pipe[PWRITE]);
@@ -358,8 +376,8 @@ sys_child_open_for_compress (void)
 	    }
 	  xdup2 (archive, STDOUT_FILENO);
 	}
-      execlp (use_compress_program_option, use_compress_program_option, NULL);
-      exec_fatal (use_compress_program_option);
+      priv_set_restore_linkdir ();
+      xexec (use_compress_program_option);
     }
 
   /* We do need a grandchild tar.  */
@@ -371,13 +389,12 @@ sys_child_open_for_compress (void)
     {
       /* The newborn grandchild tar is here!  Launch the compressor.  */
 
-      program_name = _("tar (grandchild)");
+      set_program_name (_("tar (grandchild)"));
 
       xdup2 (child_pipe[PWRITE], STDOUT_FILENO);
       xclose (child_pipe[PREAD]);
-      execlp (use_compress_program_option, use_compress_program_option,
-	      (char *) 0);
-      exec_fatal (use_compress_program_option);
+      priv_set_restore_linkdir ();
+      xexec (use_compress_program_option);
     }
 
   /* The child tar is still here!  */
@@ -444,24 +461,43 @@ sys_child_open_for_compress (void)
 	archive_write_error (status);
     }
 
-  /* Propagate any failure of the grandchild back to the parent.  */
+  wait_for_grandchild (grandchild_pid);
+}
+
+static void
+run_decompress_program (void)
+{
+  int i;
+  const char *p, *prog = NULL;
+  struct wordsplit ws;
+  int wsflags = (WRDSF_DEFFLAGS | WRDSF_ENV | WRDSF_DOOFFS) & ~WRDSF_NOVAR;
 
-  while (waitpid (grandchild_pid, &wait_status, 0) == -1)
-    if (errno != EINTR)
-      {
-	waitpid_error (use_compress_program_option);
-	break;
-      }
+  ws.ws_env = (const char **) environ;
+  ws.ws_offs = 1;
 
-  if (WIFSIGNALED (wait_status))
+  for (p = first_decompress_program (&i); p; p = next_decompress_program (&i))
     {
-      kill (child_pid, WTERMSIG (wait_status));
-      exit_status = TAREXIT_FAILURE;
+      if (prog)
+	{
+	  WARNOPT (WARN_DECOMPRESS_PROGRAM,
+		   (0, errno, _("cannot run %s"), prog));
+	  WARNOPT (WARN_DECOMPRESS_PROGRAM,
+		   (0, 0, _("trying %s"), p));
+	}
+      if (wordsplit (p, &ws, wsflags))
+	FATAL_ERROR ((0, 0, _("cannot split string '%s': %s"),
+		      p, wordsplit_strerror (&ws)));
+      wsflags |= WRDSF_REUSE;
+      memmove(ws.ws_wordv, ws.ws_wordv + ws.ws_offs,
+	      sizeof(ws.ws_wordv[0])*ws.ws_wordc);
+      ws.ws_wordv[ws.ws_wordc] = (char *) "-d";
+      prog = p;
+      execvp (ws.ws_wordv[0], ws.ws_wordv);
+      ws.ws_wordv[ws.ws_wordc] = NULL;
     }
-  else if (WEXITSTATUS (wait_status) != 0)
-    exit_status = WEXITSTATUS (wait_status);
-
-  exit (exit_status);
+  if (!prog)
+    FATAL_ERROR ((0, 0, _("unable to run decompression program")));
+  exec_fatal (prog);
 }
 
 /* Set ARCHIVE for uncompressing, then reading an archive.  */
@@ -472,7 +508,6 @@ sys_child_open_for_uncompress (void)
   int child_pipe[2];
   pid_t grandchild_pid;
   pid_t child_pid;
-  int wait_status;
 
   xpipe (parent_pipe);
   child_pid = xfork ();
@@ -488,7 +523,8 @@ sys_child_open_for_uncompress (void)
 
   /* The newborn child tar is here!  */
 
-  program_name = _("tar (child)");
+  set_program_name (_("tar (child)"));
+  signal (SIGPIPE, SIG_DFL);
 
   xdup2 (parent_pipe[PWRITE], STDOUT_FILENO);
   xclose (parent_pipe[PREAD]);
@@ -509,9 +545,8 @@ sys_child_open_for_uncompress (void)
       if (archive < 0)
 	open_fatal (archive_name_array[0]);
       xdup2 (archive, STDIN_FILENO);
-      execlp (use_compress_program_option, use_compress_program_option,
-	      "-d", (char *) 0);
-      exec_fatal (use_compress_program_option);
+      priv_set_restore_linkdir ();
+      run_decompress_program ();
     }
 
   /* We do need a grandchild tar.  */
@@ -523,13 +558,12 @@ sys_child_open_for_uncompress (void)
     {
       /* The newborn grandchild tar is here!  Launch the uncompressor.  */
 
-      program_name = _("tar (grandchild)");
+      set_program_name (_("tar (grandchild)"));
 
       xdup2 (child_pipe[PREAD], STDIN_FILENO);
       xclose (child_pipe[PWRITE]);
-      execlp (use_compress_program_option, use_compress_program_option,
-	      "-d", (char *) 0);
-      exec_fatal (use_compress_program_option);
+      priv_set_restore_linkdir ();
+      run_decompress_program ();
     }
 
   /* The child tar is still here!  */
@@ -582,30 +616,13 @@ sys_child_open_for_uncompress (void)
 
   xclose (STDOUT_FILENO);
 
-  /* Propagate any failure of the grandchild back to the parent.  */
-
-  while (waitpid (grandchild_pid, &wait_status, 0) == -1)
-    if (errno != EINTR)
-      {
-	waitpid_error (use_compress_program_option);
-	break;
-      }
-
-  if (WIFSIGNALED (wait_status))
-    {
-      kill (child_pid, WTERMSIG (wait_status));
-      exit_status = TAREXIT_FAILURE;
-    }
-  else if (WEXITSTATUS (wait_status) != 0)
-    exit_status = WEXITSTATUS (wait_status);
-
-  exit (exit_status);
+  wait_for_grandchild (grandchild_pid);
 }
 
 
 
 static void
-dec_to_env (char *envar, uintmax_t num)
+dec_to_env (char const *envar, uintmax_t num)
 {
   char buf[UINTMAX_STRSIZE_BOUND];
   char *numstr;
@@ -616,7 +633,7 @@ dec_to_env (char *envar, uintmax_t num)
 }
 
 static void
-time_to_env (char *envar, struct timespec t)
+time_to_env (char const *envar, struct timespec t)
 {
   char buf[TIMESPEC_STRSIZE_BOUND];
   if (setenv (envar, code_timespec (t, buf), 1) != 0)
@@ -624,7 +641,7 @@ time_to_env (char *envar, struct timespec t)
 }
 
 static void
-oct_to_env (char *envar, unsigned long num)
+oct_to_env (char const *envar, unsigned long num)
 {
   char buf[1+1+(sizeof(unsigned long)*CHAR_BIT+2)/3];
 
@@ -634,7 +651,7 @@ oct_to_env (char *envar, unsigned long num)
 }
 
 static void
-str_to_env (char *envar, char const *str)
+str_to_env (char const *envar, char const *str)
 {
   if (str)
     {
@@ -646,7 +663,7 @@ str_to_env (char *envar, char const *str)
 }
 
 static void
-chr_to_env (char *envar, char c)
+chr_to_env (char const *envar, char c)
 {
   char buf[2];
   buf[0] = c;
@@ -659,6 +676,12 @@ static void
 stat_to_env (char *name, char type, struct tar_stat_info *st)
 {
   str_to_env ("TAR_VERSION", PACKAGE_VERSION);
+  str_to_env ("TAR_ARCHIVE", *archive_name_cursor);
+  dec_to_env ("TAR_VOLUME", archive_name_cursor - archive_name_array + 1);
+  dec_to_env ("TAR_BLOCKING_FACTOR", blocking_factor);
+  str_to_env ("TAR_FORMAT",
+	      archive_format_string (current_format == DEFAULT_FORMAT ?
+				     archive_format : current_format));
   chr_to_env ("TAR_FILETYPE", type);
   oct_to_env ("TAR_MODE", st->stat.st_mode);
   str_to_env ("TAR_FILENAME", name);
@@ -697,13 +720,12 @@ stat_to_env (char *name, char type, struct tar_stat_info *st)
 }
 
 static pid_t global_pid;
-static RETSIGTYPE (*pipe_handler) (int sig);
+static void (*pipe_handler) (int sig);
 
 int
 sys_exec_command (char *file_name, int typechar, struct tar_stat_info *st)
 {
   int p[2];
-  char *argv[4];
 
   xpipe (p);
   pipe_handler = signal (SIGPIPE, SIG_IGN);
@@ -721,14 +743,8 @@ sys_exec_command (char *file_name, int typechar, struct tar_stat_info *st)
 
   stat_to_env (file_name, typechar, st);
 
-  argv[0] = "/bin/sh";
-  argv[1] = "-c";
-  argv[2] = to_command_option;
-  argv[3] = NULL;
-
-  execv ("/bin/sh", argv);
-
-  exec_fatal (file_name);
+  priv_set_restore_linkdir ();
+  xexec (to_command_option);
 }
 
 void
@@ -770,11 +786,10 @@ int
 sys_exec_info_script (const char **archive_name, int volume_number)
 {
   pid_t pid;
-  char *argv[4];
   char uintbuf[UINTMAX_STRSIZE_BOUND];
   int p[2];
-  static RETSIGTYPE (*saved_handler) (int sig);
-  
+  static void (*saved_handler) (int sig);
+
   xpipe (p);
   saved_handler = signal (SIGPIPE, SIG_IGN);
 
@@ -807,7 +822,7 @@ sys_exec_info_script (const char **archive_name, int volume_number)
 	  }
 
       signal (SIGPIPE, saved_handler);
-      
+
       if (WIFEXITED (status))
 	{
 	  if (WEXITSTATUS (status) == 0 && rc > 0)
@@ -835,14 +850,8 @@ sys_exec_info_script (const char **archive_name, int volume_number)
 
   xclose (p[PREAD]);
 
-  argv[0] = "/bin/sh";
-  argv[1] = "-c";
-  argv[2] = (char*) info_script_option;
-  argv[3] = NULL;
-
-  execv (argv[0], argv);
-
-  exec_fatal (info_script_option);
+  priv_set_restore_linkdir ();
+  xexec (info_script_option);
 }
 
 void
@@ -851,7 +860,6 @@ sys_exec_checkpoint_script (const char *script_name,
 			    int checkpoint_number)
 {
   pid_t pid;
-  char *argv[4];
   char uintbuf[UINTMAX_STRSIZE_BOUND];
 
   pid = xfork ();
@@ -882,14 +890,8 @@ sys_exec_checkpoint_script (const char *script_name,
   setenv ("TAR_FORMAT",
 	  archive_format_string (current_format == DEFAULT_FORMAT ?
 				 archive_format : current_format), 1);
-  argv[0] = "/bin/sh";
-  argv[1] = "-c";
-  argv[2] = (char*) script_name;
-  argv[3] = NULL;
-
-  execv (argv[0], argv);
-
-  exec_fatal (script_name);
+  priv_set_restore_linkdir ();
+  xexec (script_name);
 }
 
 #endif /* not MSDOS */