contrib/libarchive/libarchive/archive_check_magic.c

   1 /*-
   2  * Copyright (c) 2003-2007 Tim Kientzle
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "archive_platform.h"
  27 __FBSDID("$FreeBSD: src/lib/libarchive/archive_check_magic.c,v 1.9 2008/12/06 05:52:01 kientzle Exp $");
  28
  29 #ifdef HAVE_SYS_TYPES_H
  30 #include <sys/types.h>
  31 #endif
  32
  33 #include <stdio.h>
  34 #ifdef HAVE_STDLIB_H
  35 #include <stdlib.h>
  36 #endif
  37 #ifdef HAVE_STRING_H
  38 #include <string.h>
  39 #endif
  40 #ifdef HAVE_UNISTD_H
  41 #include <unistd.h>
  42 #endif
  43 #if defined(_WIN32) && !defined(__CYGWIN__)
  44 #include <windows.h>
  45 #include <winbase.h>
  46 #endif
  47
  48 #include "archive_private.h"
  49
  50 static void
  51 errmsg(const char *m)
  52 {
  53         write(2, m, strlen(m));
  54 }
  55
  56 static void
  57 diediedie(void)
  58 {
  59 #if defined(_WIN32) && !defined(__CYGWIN__) && defined(_DEBUG)
  60         /* Cause a breakpoint exception  */
  61         DebugBreak();
  62 #endif
  63         *(char *)0 = 1; /* Deliberately segfault and force a coredump. */
  64         _exit(1);       /* If that didn't work, just exit with an error. */
  65 }
  66
  67 static const char *
  68 state_name(unsigned s)
  69 {
  70         switch (s) {
  71         case ARCHIVE_STATE_NEW:         return ("new");
  72         case ARCHIVE_STATE_HEADER:      return ("header");
  73         case ARCHIVE_STATE_DATA:        return ("data");
  74         case ARCHIVE_STATE_EOF:         return ("eof");
  75         case ARCHIVE_STATE_CLOSED:      return ("closed");
  76         case ARCHIVE_STATE_FATAL:       return ("fatal");
  77         default:                        return ("??");
  78         }
  79 }
  80
  81
  82 static void
  83 write_all_states(unsigned int states)
  84 {
  85         unsigned int lowbit;
  86
  87         /* A trick for computing the lowest set bit. */
  88         while ((lowbit = states & (-states)) != 0) {
  89                 states &= ~lowbit;              /* Clear the low bit. */
  90                 errmsg(state_name(lowbit));
  91                 if (states != 0)
  92                         errmsg("/");
  93         }
  94 }
  95
  96 /*
  97  * Check magic value and current state; bail if it isn't valid.
  98  *
  99  * This is designed to catch serious programming errors that violate
 100  * the libarchive API.
 101  */
 102 void
 103 __archive_check_magic(struct archive *a, unsigned int magic,
 104     unsigned int state, const char *function)
 105 {
 106         if (a->magic != magic) {
 107                 errmsg("INTERNAL ERROR: Function ");
 108                 errmsg(function);
 109                 errmsg(" invoked with invalid struct archive structure.\n");
 110                 diediedie();
 111         }
 112
 113         if (state == ARCHIVE_STATE_ANY)
 114                 return;
 115
 116         if ((a->state & state) == 0) {
 117                 errmsg("INTERNAL ERROR: Function '");
 118                 errmsg(function);
 119                 errmsg("' invoked with archive structure in state '");
 120                 write_all_states(a->state);
 121                 errmsg("', should be in state '");
 122                 write_all_states(state);
 123                 errmsg("'\n");
 124                 diediedie();
 125         }
 126 }