xref: /openbsd/usr.sbin/smtpd/compress_gzip.c (revision 097a140d)
1 /*	$OpenBSD: compress_gzip.c,v 1.11 2021/01/23 16:11:11 rob Exp $	*/
2 
3 /*
4  * Copyright (c) 2012 Gilles Chehade <gilles@poolp.org>
5  * Copyright (c) 2012 Charles Longeau <chl@openbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <sys/types.h>
21 #include <sys/queue.h>
22 #include <sys/tree.h>
23 #include <sys/socket.h>
24 #include <sys/stat.h>
25 
26 #include <ctype.h>
27 #include <err.h>
28 #include <fcntl.h>
29 #include <imsg.h>
30 #include <pwd.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <unistd.h>
35 #include <limits.h>
36 
37 #include <zlib.h>
38 
39 #include "smtpd.h"
40 #include "log.h"
41 
42 
43 #define	GZIP_BUFFER_SIZE	16384
44 
45 
46 static size_t	compress_gzip_chunk(void *, size_t, void *, size_t);
47 static size_t	uncompress_gzip_chunk(void *, size_t, void *, size_t);
48 static int	compress_gzip_file(FILE *, FILE *);
49 static int	uncompress_gzip_file(FILE *, FILE *);
50 
51 
52 struct compress_backend	compress_gzip = {
53 	compress_gzip_chunk,
54 	uncompress_gzip_chunk,
55 
56 	compress_gzip_file,
57 	uncompress_gzip_file,
58 };
59 
60 static size_t
61 compress_gzip_chunk(void *ib, size_t ibsz, void *ob, size_t obsz)
62 {
63 	z_stream       *strm;
64 	size_t		ret = 0;
65 
66 	if ((strm = calloc(1, sizeof *strm)) == NULL)
67 		return 0;
68 
69 	strm->zalloc = Z_NULL;
70 	strm->zfree = Z_NULL;
71 	strm->opaque = Z_NULL;
72 	if (deflateInit2(strm, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
73 		(15+16), 8, Z_DEFAULT_STRATEGY) != Z_OK)
74 		goto end;
75 
76 	strm->avail_in  = ibsz;
77 	strm->next_in   = (unsigned char *)ib;
78 	strm->avail_out = obsz;
79 	strm->next_out  = (unsigned char *)ob;
80 	if (deflate(strm, Z_FINISH) != Z_STREAM_END)
81 		goto end;
82 
83 	ret = strm->total_out;
84 
85 end:
86 	deflateEnd(strm);
87 	free(strm);
88 	return ret;
89 }
90 
91 
92 static size_t
93 uncompress_gzip_chunk(void *ib, size_t ibsz, void *ob, size_t obsz)
94 {
95 	z_stream       *strm;
96 	size_t		ret = 0;
97 
98 	if ((strm = calloc(1, sizeof *strm)) == NULL)
99 		return 0;
100 
101 	strm->zalloc   = Z_NULL;
102 	strm->zfree    = Z_NULL;
103 	strm->opaque   = Z_NULL;
104 	strm->avail_in = 0;
105 	strm->next_in  = Z_NULL;
106 
107 	if (inflateInit2(strm, (15+16)) != Z_OK)
108 		goto end;
109 
110 	strm->avail_in  = ibsz;
111 	strm->next_in   = (unsigned char *)ib;
112 	strm->avail_out = obsz;
113 	strm->next_out  = (unsigned char *)ob;
114 
115 	if (inflate(strm, Z_FINISH) != Z_STREAM_END)
116 		goto end;
117 
118 	ret = strm->total_out;
119 
120 end:
121 	deflateEnd(strm);
122 	free(strm);
123 	return ret;
124 }
125 
126 
127 static int
128 compress_gzip_file(FILE *in, FILE *out)
129 {
130 	gzFile  gzf;
131 	char  ibuf[GZIP_BUFFER_SIZE];
132 	int  r;
133 	int  ret = 0;
134 
135 	if (in == NULL || out == NULL)
136 		return (0);
137 
138 	gzf = gzdopen(fileno(out), "wb");
139 	if (gzf == NULL)
140 		return (0);
141 
142 	while ((r = fread(ibuf, 1, GZIP_BUFFER_SIZE, in)) != 0) {
143 		if (gzwrite(gzf, ibuf, r) != r)
144 			goto end;
145 	}
146 	if (!feof(in))
147 		goto end;
148 
149 	ret = 1;
150 
151 end:
152 	gzclose(gzf);
153 	return (ret);
154 }
155 
156 
157 static int
158 uncompress_gzip_file(FILE *in, FILE *out)
159 {
160 	gzFile  gzf;
161 	char  obuf[GZIP_BUFFER_SIZE];
162 	int  r;
163 	int  ret = 0;
164 
165 	if (in == NULL || out == NULL)
166 		return (0);
167 
168 	gzf = gzdopen(fileno(in), "r");
169 	if (gzf == NULL)
170 		return (0);
171 
172 	while ((r = gzread(gzf, obuf, sizeof(obuf))) > 0) {
173 		if  (fwrite(obuf, r, 1, out) != 1)
174 			goto end;
175 	}
176 	if (!gzeof(gzf))
177 		goto end;
178 
179 	ret = 1;
180 
181 end:
182 	gzclose(gzf);
183 	return (ret);
184 }
185