archive_check_magic.c revision 228761 
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: 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
50static void
51errmsg(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
65static void
66diediedie(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
75static const char *
76state_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
90static void
91write_all_states(unsigned int states)
92{
93	unsigned int lowbit;
94
95	/* A trick for computing the lowest set bit. */
96	while ((lowbit = states & (1 + ~states)) != 0) {
97		states &= ~lowbit;		/* Clear the low bit. */
98		errmsg(state_name(lowbit));
99		if (states != 0)
100			errmsg("/");
101	}
102}
103
104/*
105 * Check magic value and current state; bail if it isn't valid.
106 *
107 * This is designed to catch serious programming errors that violate
108 * the libarchive API.
109 */
110void
111__archive_check_magic(struct archive *a, unsigned int magic,
112    unsigned int state, const char *function)
113{
114	if (a->magic != magic) {
115		errmsg("INTERNAL ERROR: Function ");
116		errmsg(function);
117		errmsg(" invoked with invalid struct archive structure.\n");
118		diediedie();
119	}
120
121	if (state == ARCHIVE_STATE_ANY)
122		return;
123
124	if ((a->state & state) == 0) {
125		errmsg("INTERNAL ERROR: Function '");
126		errmsg(function);
127		errmsg("' invoked with archive structure in state '");
128		write_all_states(a->state);
129		errmsg("', should be in state '");
130		write_all_states(state);
131		errmsg("'\n");
132		diediedie();
133	}
134}
135