diff options
author | Damien Miller <djm@mindrot.org> | 1999-10-27 13:42:43 +1000 |
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committer | Damien Miller <djm@mindrot.org> | 1999-10-27 13:42:43 +1000 |
commit | d4a8b7e34dd619a4debf9a206c81db26d1402ea6 (patch) | |
tree | a47d770a2f790f40d18b0982d4e55fa7cfb1fa3b /compress.c |
Initial revision
Diffstat (limited to 'compress.c')
-rw-r--r-- | compress.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/compress.c b/compress.c new file mode 100644 index 000000000..c3267f73f --- /dev/null +++ b/compress.c | |||
@@ -0,0 +1,160 @@ | |||
1 | /* | ||
2 | |||
3 | compress.c | ||
4 | |||
5 | Author: Tatu Ylonen <ylo@cs.hut.fi> | ||
6 | |||
7 | Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | ||
8 | All rights reserved | ||
9 | |||
10 | Created: Wed Oct 25 22:12:46 1995 ylo | ||
11 | |||
12 | Interface to packet compression for ssh. | ||
13 | |||
14 | */ | ||
15 | |||
16 | #include "includes.h" | ||
17 | RCSID("$Id: compress.c,v 1.1 1999/10/27 03:42:44 damien Exp $"); | ||
18 | |||
19 | #include "ssh.h" | ||
20 | #include "buffer.h" | ||
21 | #include "zlib.h" | ||
22 | |||
23 | static z_stream incoming_stream; | ||
24 | static z_stream outgoing_stream; | ||
25 | |||
26 | /* Initializes compression; level is compression level from 1 to 9 (as in | ||
27 | gzip). */ | ||
28 | |||
29 | void buffer_compress_init(int level) | ||
30 | { | ||
31 | debug("Enabling compression at level %d.", level); | ||
32 | if (level < 1 || level > 9) | ||
33 | fatal("Bad compression level %d.", level); | ||
34 | inflateInit(&incoming_stream); | ||
35 | deflateInit(&outgoing_stream, level); | ||
36 | } | ||
37 | |||
38 | /* Frees any data structures allocated for compression. */ | ||
39 | |||
40 | void buffer_compress_uninit() | ||
41 | { | ||
42 | debug("compress outgoing: raw data %lu, compressed %lu, factor %.2f", | ||
43 | outgoing_stream.total_in, outgoing_stream.total_out, | ||
44 | outgoing_stream.total_in == 0 ? 0.0 : | ||
45 | (double)outgoing_stream.total_out / outgoing_stream.total_in); | ||
46 | debug("compress incoming: raw data %lu, compressed %lu, factor %.2f", | ||
47 | incoming_stream.total_out, incoming_stream.total_in, | ||
48 | incoming_stream.total_out == 0 ? 0.0 : | ||
49 | (double)incoming_stream.total_in / incoming_stream.total_out); | ||
50 | inflateEnd(&incoming_stream); | ||
51 | deflateEnd(&outgoing_stream); | ||
52 | } | ||
53 | |||
54 | /* Compresses the contents of input_buffer into output_buffer. All | ||
55 | packets compressed using this function will form a single | ||
56 | compressed data stream; however, data will be flushed at the end of | ||
57 | every call so that each output_buffer can be decompressed | ||
58 | independently (but in the appropriate order since they together | ||
59 | form a single compression stream) by the receiver. This appends | ||
60 | the compressed data to the output buffer. */ | ||
61 | |||
62 | void buffer_compress(Buffer *input_buffer, Buffer *output_buffer) | ||
63 | { | ||
64 | char buf[4096]; | ||
65 | int status; | ||
66 | |||
67 | /* This case is not handled below. */ | ||
68 | if (buffer_len(input_buffer) == 0) | ||
69 | return; | ||
70 | |||
71 | /* Input is the contents of the input buffer. */ | ||
72 | outgoing_stream.next_in = buffer_ptr(input_buffer); | ||
73 | outgoing_stream.avail_in = buffer_len(input_buffer); | ||
74 | |||
75 | /* Loop compressing until deflate() returns with avail_out != 0. */ | ||
76 | do | ||
77 | { | ||
78 | /* Set up fixed-size output buffer. */ | ||
79 | outgoing_stream.next_out = buf; | ||
80 | outgoing_stream.avail_out = sizeof(buf); | ||
81 | |||
82 | /* Compress as much data into the buffer as possible. */ | ||
83 | status = deflate(&outgoing_stream, Z_PARTIAL_FLUSH); | ||
84 | switch (status) | ||
85 | { | ||
86 | case Z_OK: | ||
87 | /* Append compressed data to output_buffer. */ | ||
88 | buffer_append(output_buffer, buf, | ||
89 | sizeof(buf) - outgoing_stream.avail_out); | ||
90 | break; | ||
91 | case Z_STREAM_END: | ||
92 | fatal("buffer_compress: deflate returned Z_STREAM_END"); | ||
93 | /*NOTREACHED*/ | ||
94 | case Z_STREAM_ERROR: | ||
95 | fatal("buffer_compress: deflate returned Z_STREAM_ERROR"); | ||
96 | /*NOTREACHED*/ | ||
97 | case Z_BUF_ERROR: | ||
98 | fatal("buffer_compress: deflate returned Z_BUF_ERROR"); | ||
99 | /*NOTREACHED*/ | ||
100 | default: | ||
101 | fatal("buffer_compress: deflate returned %d", status); | ||
102 | /*NOTREACHED*/ | ||
103 | } | ||
104 | } | ||
105 | while (outgoing_stream.avail_out == 0); | ||
106 | } | ||
107 | |||
108 | /* Uncompresses the contents of input_buffer into output_buffer. All | ||
109 | packets uncompressed using this function will form a single | ||
110 | compressed data stream; however, data will be flushed at the end of | ||
111 | every call so that each output_buffer. This must be called for the | ||
112 | same size units that the buffer_compress was called, and in the | ||
113 | same order that buffers compressed with that. This appends the | ||
114 | uncompressed data to the output buffer. */ | ||
115 | |||
116 | void buffer_uncompress(Buffer *input_buffer, Buffer *output_buffer) | ||
117 | { | ||
118 | char buf[4096]; | ||
119 | int status; | ||
120 | |||
121 | incoming_stream.next_in = buffer_ptr(input_buffer); | ||
122 | incoming_stream.avail_in = buffer_len(input_buffer); | ||
123 | |||
124 | incoming_stream.next_out = buf; | ||
125 | incoming_stream.avail_out = sizeof(buf); | ||
126 | |||
127 | for (;;) | ||
128 | { | ||
129 | status = inflate(&incoming_stream, Z_PARTIAL_FLUSH); | ||
130 | switch (status) | ||
131 | { | ||
132 | case Z_OK: | ||
133 | buffer_append(output_buffer, buf, | ||
134 | sizeof(buf) - incoming_stream.avail_out); | ||
135 | incoming_stream.next_out = buf; | ||
136 | incoming_stream.avail_out = sizeof(buf); | ||
137 | break; | ||
138 | case Z_STREAM_END: | ||
139 | fatal("buffer_uncompress: inflate returned Z_STREAM_END"); | ||
140 | /*NOTREACHED*/ | ||
141 | case Z_DATA_ERROR: | ||
142 | fatal("buffer_uncompress: inflate returned Z_DATA_ERROR"); | ||
143 | /*NOTREACHED*/ | ||
144 | case Z_STREAM_ERROR: | ||
145 | fatal("buffer_uncompress: inflate returned Z_STREAM_ERROR"); | ||
146 | /*NOTREACHED*/ | ||
147 | case Z_BUF_ERROR: | ||
148 | /* Comments in zlib.h say that we should keep calling inflate() | ||
149 | until we get an error. This appears to be the error that we | ||
150 | get. */ | ||
151 | return; | ||
152 | case Z_MEM_ERROR: | ||
153 | fatal("buffer_uncompress: inflate returned Z_MEM_ERROR"); | ||
154 | /*NOTREACHED*/ | ||
155 | default: | ||
156 | fatal("buffer_uncompress: inflate returned %d", status); | ||
157 | } | ||
158 | } | ||
159 | } | ||
160 | |||