summaryrefslogtreecommitdiffstats
path: root/mdk-stage1/mar/mar-extract-only.c
blob: 723cc376d61fc3e7f22346f98fa35575d0ac3e76 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
/*
 * Guillaume Cottenceau (gc@mandrakesoft.com)
 *
 * Copyright 2000 MandrakeSoft
 *
 * This software may be freely redistributed under the terms of the GNU
 * public license.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

/*
 * mar - The Mandrake Archiver
 *
 * An archiver that supports compression (through zlib).
 *
 */

/*
 * This code should suffice for stage1 on-the-fly uncompression of kernel modules.
 * (and it DOES perform tests and return values, blaaaah..)
 */

#include "mar-extract-only.h"
#include "mar.h"

#ifdef _STANDALONE_
void
zerr(BZFILE * f) /* decrease code size */
{
	fprintf(stderr, BZ2_bzerror(f, &z_errnum));
}

inline void
log_perror(char *msg)
{
	perror(msg);
}
void
log_message(char *msg)
{
	fprintf(stderr, msg);
}
#else /* _STANDALONE_ */
#include "../log.h"
void
zerr(BZFILE * f) /* decrease code size */
{
	log_message(BZ2_bzerror(f, &z_errnum));
}
#endif /* _STANDALONE_ */


static int
mar_open_file(char *filename, struct mar_stream *s)
{
	int end_filetable = 0;
	struct mar_element * previous_element = NULL;

	/* mar_zfile */
	s->mar_zfile = BZ2_bzopen(filename, "rb");
	if (!s->mar_zfile)
	{
		log_perror(filename);
		return -1;
	}

	while (end_filetable == 0)
	{
		char buf[512];
		int ptr = 0;
		/* read filename */
		do
		{
			if (BZ2_bzread(s->mar_zfile, &(buf[ptr]), sizeof(char)) != sizeof(char))
			{
				zerr(s->mar_zfile);
				return -1;
			}
			ptr++;
		} while ((buf[ptr-1] != 0) && (ptr < 512));
		/* ptr == 1 when we arrive on the "char 0" of the end of the filetable */
		if (ptr > 1)
		{
			struct mar_element * e = (struct mar_element *) malloc(sizeof(struct mar_element));
			e->filename = strdup(buf);
			/* read file_length */
			if (BZ2_bzread(s->mar_zfile, &(e->file_length), sizeof(int)) != sizeof(int))
			{
				zerr(s->mar_zfile);
				return -1;
			}
			/* read data_offset */
			if (BZ2_bzread(s->mar_zfile, &(e->data_offset), sizeof(int)) != sizeof(int))
			{
				zerr(s->mar_zfile);
				return -1;
			}
			/* write down chaining */
			if (previous_element)
				previous_element->next_element = e;
			else
				s->first_element = e;
			previous_element = e;
		}
		else
			end_filetable = 1;

	}
	/* chaining for last element */
	previous_element->next_element = NULL;

	return 0;
}


char **
mar_list_contents(char * mar_filename)
{
	struct mar_stream s;
	struct mar_element * elem;
	char * tmp_contents[500];
	char ** answ;
	int i = 0;

	if (mar_open_file(mar_filename, &s))
		return NULL;

	elem = s.first_element;
	while (elem)
	{
		tmp_contents[i++] = strdup(elem->filename);
		elem = elem->next_element;
	}
	tmp_contents[i++] = NULL;
	answ = (char **) malloc(sizeof(char *) * i);
	memcpy(answ, tmp_contents, sizeof(char *) * i);
	return answ;
}


int
mar_extract_file(char *mar_filename, char *filename_to_extract, char *dest_dir)
{
	struct mar_stream s;
	struct mar_element * elem;

	if (mar_open_file(mar_filename, &s))
		return -1;

	elem = s.first_element;
	while (elem)
	{
		if (strcmp(elem->filename, filename_to_extract) == 0)
		{
			char garb_buf[4096];
			char *buf;
			char *dest_file;
			int fd, i;
			dest_file = (char *) alloca(strlen(dest_dir) + strlen(filename_to_extract) + 1);
			strcpy(dest_file, dest_dir);
			strcat(dest_file, filename_to_extract);
			fd = creat(dest_file, 00660);
			if (fd == -1)
			{
				log_perror(dest_file);
				return -1;
			}
			buf = (char *) alloca(elem->file_length);
			if (!buf)
			{
				log_perror(dest_file);
				return -1;
			}
			i = elem->data_offset;
			while (i > 0) {
				int to_read = i > sizeof(garb_buf) ? sizeof(garb_buf) : i;
				if (BZ2_bzread(s.mar_zfile, garb_buf, to_read) != to_read) {
					log_message("MAR: unexpected EOF in stream");
					return -1;
				}
				i -= to_read;
			}
			if (BZ2_bzread(s.mar_zfile, buf, elem->file_length) != elem->file_length)
			{
				zerr(s.mar_zfile);
				return -1;
			}
			if (write(fd, buf, elem->file_length) != elem->file_length)
			{
				log_perror(dest_file);
				return -1;
			}
			close(fd); /* do not check return value for code size */
			BZ2_bzclose(s.mar_zfile);
			return 0;
		}
		elem = elem->next_element;
	}
	BZ2_bzclose(s.mar_zfile);
	return 1; /* 1 for file_not_found_in_archive */
}