contrib/libarchive/libarchive/archive_check_magic.c

   1 /*-
   2  * Copyright (c) 2003-2010 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: head/lib/libarchive/archive_check_magic.c 201089 2009-12-28 02:20:23Z kientzle $");
  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         size_t s = strlen(m);
  54         ssize_t written;
  55
  56         while (s > 0) {
  57                 written = write(2, m, strlen(m));
  58                 if (written <= 0)
  59                         return;
  60                 m += written;
  61                 s -= written;
  62         }
  63 }
  64
  65 static void
  66 diediedie(void)
  67 {
  68 #if defined(_WIN32) && !defined(__CYGWIN__) && defined(_DEBUG)
  69         /* Cause a breakpoint exception  */
  70         DebugBreak();
  71 #endif
  72         abort();        /* Terminate the program abnormally. */
  73 }
  74
  75 static const char *
  76 state_name(unsigned s)
  77 {
  78         switch (s) {
  79         case ARCHIVE_STATE_NEW:         return ("new");
  80         case ARCHIVE_STATE_HEADER:      return ("header");
  81         case ARCHIVE_STATE_DATA:        return ("data");
  82         case ARCHIVE_STATE_EOF:         return ("eof");
  83         case ARCHIVE_STATE_CLOSED:      return ("closed");
  84         case ARCHIVE_STATE_FATAL:       return ("fatal");
  85         default:                        return ("??");
  86         }
  87 }
  88
  89 static const char *
  90 archive_handle_type_name(unsigned m)
  91 {
  92         switch (m) {
  93         case ARCHIVE_WRITE_MAGIC:       return ("archive_write");
  94         case ARCHIVE_READ_MAGIC:        return ("archive_read");
  95         case ARCHIVE_WRITE_DISK_MAGIC:  return ("archive_write_disk");
  96         case ARCHIVE_READ_DISK_MAGIC:   return ("archive_read_disk");
  97         case ARCHIVE_MATCH_MAGIC:       return ("archive_match");
  98         default:                        return NULL;
  99         }
 100 }
 101
 102
 103 static char *
 104 write_all_states(char *buff, unsigned int states)
 105 {
 106         unsigned int lowbit;
 107
 108         buff[0] = '\0';
 109
 110         /* A trick for computing the lowest set bit. */
 111         while ((lowbit = states & (1 + ~states)) != 0) {
 112                 states &= ~lowbit;              /* Clear the low bit. */
 113                 strcat(buff, state_name(lowbit));
 114                 if (states != 0)
 115                         strcat(buff, "/");
 116         }
 117         return buff;
 118 }
 119
 120 /*
 121  * Check magic value and current state.
 122  *   Magic value mismatches are fatal and result in calls to abort().
 123  *   State mismatches return ARCHIVE_FATAL.
 124  *   Otherwise, returns ARCHIVE_OK.
 125  *
 126  * This is designed to catch serious programming errors that violate
 127  * the libarchive API.
 128  */
 129 int
 130 __archive_check_magic(struct archive *a, unsigned int magic,
 131     unsigned int state, const char *function)
 132 {
 133         char states1[64];
 134         char states2[64];
 135         const char *handle_type;
 136
 137         /*
 138          * If this isn't some form of archive handle,
 139          * then the library user has screwed up so bad that
 140          * we don't even have a reliable way to report an error.
 141          */
 142         handle_type = archive_handle_type_name(a->magic);
 143
 144         if (!handle_type) {
 145                 errmsg("PROGRAMMER ERROR: Function ");
 146                 errmsg(function);
 147                 errmsg(" invoked with invalid archive handle.\n");
 148                 diediedie();
 149         }
 150
 151         if (a->magic != magic) {
 152                 archive_set_error(a, -1,
 153                     "PROGRAMMER ERROR: Function '%s' invoked"
 154                     " on '%s' archive object, which is not supported.",
 155                     function,
 156                     handle_type);
 157                 a->state = ARCHIVE_STATE_FATAL;
 158                 return (ARCHIVE_FATAL);
 159         }
 160
 161         if ((a->state & state) == 0) {
 162                 /* If we're already FATAL, don't overwrite the error. */
 163                 if (a->state != ARCHIVE_STATE_FATAL)
 164                         archive_set_error(a, -1,
 165                             "INTERNAL ERROR: Function '%s' invoked with"
 166                             " archive structure in state '%s',"
 167                             " should be in state '%s'",
 168                             function,
 169                             write_all_states(states1, a->state),
 170                             write_all_states(states2, state));
 171                 a->state = ARCHIVE_STATE_FATAL;
 172                 return (ARCHIVE_FATAL);
 173         }
 174         return ARCHIVE_OK;
 175 }