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, s); 58 if (written <= 0) 59 return; 60 m += written; 61 s -= written; 62 } 63 } 64 65 static __LA_DEAD 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 } 176