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
errmsg(const char * m)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
diediedie(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 *
state_name(unsigned s)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 *
archive_handle_type_name(unsigned m)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 *
write_all_states(char * buff,unsigned int states)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
__archive_check_magic(struct archive * a,unsigned int magic,unsigned int state,const char * function)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