1 /* $OpenBSD: xform_ipcomp.c,v 1.8 2019/01/09 12:11:38 mpi Exp $ */
2
3 /*
4 * Copyright (c) 2001 Jean-Jacques Bernard-Gundol (jj@wabbitt.org)
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 /*
31 * This file contains a wrapper around the deflate algo compression
32 * functions using the zlib library
33 */
34
35 #include <sys/param.h>
36 #include <sys/malloc.h>
37 #include <sys/systm.h>
38 #include <lib/libz/zutil.h>
39
40 #define Z_METHOD 8
41 #define Z_MEMLEVEL 8
42 #define ZBUF 10
43
44 u_int32_t deflate_global(u_int8_t *, u_int32_t, int, u_int8_t **);
45
46 struct deflate_buf {
47 u_int8_t *out;
48 u_int32_t size;
49 int flag;
50 };
51
52 int window_inflate = -1 * MAX_WBITS;
53 int window_deflate = -12;
54
55 /*
56 * This function takes a block of data and (de)compress it using the deflate
57 * algorithm
58 */
59
60 u_int32_t
deflate_global(u_int8_t * data,u_int32_t size,int decomp,u_int8_t ** out)61 deflate_global(u_int8_t *data, u_int32_t size, int decomp, u_int8_t **out)
62 {
63 z_stream zbuf;
64 u_int8_t *output;
65 u_int32_t count, result;
66 int error, i = 0, j;
67 struct deflate_buf buf[ZBUF];
68
69 bzero(&zbuf, sizeof(z_stream));
70 for (j = 0; j < ZBUF; j++)
71 buf[j].flag = 0;
72
73 zbuf.next_in = data; /* data that is going to be processed */
74 zbuf.zalloc = zcalloc;
75 zbuf.zfree = zcfree;
76 zbuf.opaque = Z_NULL;
77 zbuf.avail_in = size; /* Total length of data to be processed */
78
79 if (decomp) {
80 /*
81 * Choose a buffer with 4x the size of the input buffer
82 * for the size of the output buffer in the case of
83 * decompression. If it's not sufficient, it will need to be
84 * updated while the decompression is going on
85 */
86 if (size < 32 * 1024)
87 size *= 4;
88 }
89 buf[i].out = malloc((u_long)size, M_CRYPTO_DATA, M_NOWAIT);
90 if (buf[i].out == NULL)
91 goto bad;
92 buf[i].size = size;
93 buf[i].flag = 1;
94 i++;
95
96 zbuf.next_out = buf[0].out;
97 zbuf.avail_out = buf[0].size;
98
99 error = decomp ?
100 inflateInit2(&zbuf, window_inflate) :
101 deflateInit2(&zbuf, Z_DEFAULT_COMPRESSION, Z_METHOD,
102 window_deflate, Z_MEMLEVEL, Z_DEFAULT_STRATEGY);
103
104 if (error != Z_OK)
105 goto bad;
106 for (;;) {
107 error = decomp ?
108 inflate(&zbuf, Z_PARTIAL_FLUSH) :
109 deflate(&zbuf, Z_FINISH);
110 if (error == Z_STREAM_END)
111 break;
112 if (error != Z_OK)
113 goto bad;
114 if (zbuf.avail_out == 0 && i < (ZBUF - 1)) {
115 /* we need more output space, allocate size */
116 if (size < 32 * 1024)
117 size *= 2;
118 buf[i].out = malloc((u_long)size, M_CRYPTO_DATA,
119 M_NOWAIT);
120 if (buf[i].out == NULL)
121 goto bad;
122 zbuf.next_out = buf[i].out;
123 buf[i].size = size;
124 buf[i].flag = 1;
125 zbuf.avail_out = buf[i].size;
126 i++;
127 } else
128 goto bad; /* out of buffers */
129 }
130 result = count = zbuf.total_out;
131
132 *out = malloc((u_long)result, M_CRYPTO_DATA, M_NOWAIT);
133 if (*out == NULL)
134 goto bad;
135 if (decomp)
136 inflateEnd(&zbuf);
137 else
138 deflateEnd(&zbuf);
139 output = *out;
140 for (j = 0; buf[j].flag != 0; j++) {
141 if (count > buf[j].size) {
142 bcopy(buf[j].out, *out, buf[j].size);
143 *out += buf[j].size;
144 free(buf[j].out, M_CRYPTO_DATA, buf[j].size);
145 count -= buf[j].size;
146 } else {
147 /* it should be the last buffer */
148 bcopy(buf[j].out, *out, count);
149 *out += count;
150 free(buf[j].out, M_CRYPTO_DATA, buf[j].size);
151 count = 0;
152 }
153 }
154 *out = output;
155 return result;
156
157 bad:
158 *out = NULL;
159 for (j = 0; buf[j].flag != 0; j++)
160 free(buf[j].out, M_CRYPTO_DATA, buf[j].size);
161 if (decomp)
162 inflateEnd(&zbuf);
163 else
164 deflateEnd(&zbuf);
165 return 0;
166 }
167