xref: /freebsd/contrib/libarchive/libarchive/archive_check_magic.c (revision b9128a37faafede823eb456aa65a11ac69997284)
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 
28 #ifdef HAVE_SYS_TYPES_H
29 #include <sys/types.h>
30 #endif
31 
32 #include <stdio.h>
33 #ifdef HAVE_STDLIB_H
34 #include <stdlib.h>
35 #endif
36 #ifdef HAVE_STRING_H
37 #include <string.h>
38 #endif
39 #ifdef HAVE_UNISTD_H
40 #include <unistd.h>
41 #endif
42 #if defined(_WIN32) && !defined(__CYGWIN__)
43 #include <windows.h>
44 #include <winbase.h>
45 #endif
46 
47 #include "archive_private.h"
48 
49 static void
50 errmsg(const char *m)
51 {
52 	size_t s = strlen(m);
53 	ssize_t written;
54 
55 	while (s > 0) {
56 		written = write(2, m, s);
57 		if (written <= 0)
58 			return;
59 		m += written;
60 		s -= written;
61 	}
62 }
63 
64 static __LA_NORETURN void
65 diediedie(void)
66 {
67 #if defined(_WIN32) && !defined(__CYGWIN__) && defined(_DEBUG)
68 	/* Cause a breakpoint exception  */
69 	DebugBreak();
70 #endif
71 	abort();        /* Terminate the program abnormally. */
72 }
73 
74 static const char *
75 state_name(unsigned s)
76 {
77 	switch (s) {
78 	case ARCHIVE_STATE_NEW:		return ("new");
79 	case ARCHIVE_STATE_HEADER:	return ("header");
80 	case ARCHIVE_STATE_DATA:	return ("data");
81 	case ARCHIVE_STATE_EOF:		return ("eof");
82 	case ARCHIVE_STATE_CLOSED:	return ("closed");
83 	case ARCHIVE_STATE_FATAL:	return ("fatal");
84 	default:			return ("??");
85 	}
86 }
87 
88 static const char *
89 archive_handle_type_name(unsigned m)
90 {
91 	switch (m) {
92 	case ARCHIVE_WRITE_MAGIC:	return ("archive_write");
93 	case ARCHIVE_READ_MAGIC:	return ("archive_read");
94 	case ARCHIVE_WRITE_DISK_MAGIC:	return ("archive_write_disk");
95 	case ARCHIVE_READ_DISK_MAGIC:	return ("archive_read_disk");
96 	case ARCHIVE_MATCH_MAGIC:	return ("archive_match");
97 	default:			return NULL;
98 	}
99 }
100 
101 static void
102 write_all_states(char *buff, unsigned int states)
103 {
104 	unsigned int lowbit;
105 
106 	*buff = '\0';
107 
108 	/* A trick for computing the lowest set bit. */
109 	while ((lowbit = states & (1 + ~states)) != 0) {
110 		states &= ~lowbit;		/* Clear the low bit. */
111 		strcat(buff, state_name(lowbit));
112 		if (states != 0)
113 			strcat(buff, "/");
114 	}
115 }
116 
117 /*
118  * Check magic value and current state.
119  *   Magic value mismatches are fatal and result in calls to abort().
120  *   State mismatches return ARCHIVE_FATAL.
121  *   Otherwise, returns ARCHIVE_OK.
122  *
123  * This is designed to catch serious programming errors that violate
124  * the libarchive API.
125  */
126 int
127 __archive_check_magic(struct archive *a, unsigned int magic,
128     unsigned int state, const char *function)
129 {
130 	char states1[64];
131 	char states2[64];
132 	const char *handle_type;
133 
134 	/*
135 	 * If this isn't some form of archive handle,
136 	 * then the library user has screwed up so bad that
137 	 * we don't even have a reliable way to report an error.
138 	 */
139 	handle_type = archive_handle_type_name(a->magic);
140 
141 	if (!handle_type) {
142 		errmsg("PROGRAMMER ERROR: Function ");
143 		errmsg(function);
144 		errmsg(" invoked with invalid archive handle.\n");
145 		diediedie();
146 	}
147 
148 	if (a->magic != magic) {
149 		archive_set_error(a, -1,
150 		    "PROGRAMMER ERROR: Function '%s' invoked"
151 		    " on '%s' archive object, which is not supported.",
152 		    function,
153 		    handle_type);
154 		a->state = ARCHIVE_STATE_FATAL;
155 		return (ARCHIVE_FATAL);
156 	}
157 
158 	if ((a->state & state) == 0) {
159 		/* If we're already FATAL, don't overwrite the error. */
160 		if (a->state != ARCHIVE_STATE_FATAL) {
161 			write_all_states(states1, a->state);
162 			write_all_states(states2, state);
163 			archive_set_error(a, -1,
164 			    "INTERNAL ERROR: Function '%s' invoked with"
165 			    " archive structure in state '%s',"
166 			    " should be in state '%s'",
167 			    function,
168 			    states1,
169 			    states2);
170 		}
171 		a->state = ARCHIVE_STATE_FATAL;
172 		return (ARCHIVE_FATAL);
173 	}
174 	return (ARCHIVE_OK);
175 }
176