/*
- *
- * compress.c
- *
* Author: Tatu Ylonen <ylo@cs.hut.fi>
- *
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
- *
- * Created: Wed Oct 25 22:12:46 1995 ylo
- *
* Interface to packet compression for ssh.
- *
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose. Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
*/
#include "includes.h"
-RCSID("$Id$");
+RCSID("$OpenBSD: compress.c,v 1.19 2002/03/18 17:31:54 provos Exp $");
-#include "ssh.h"
+#include "log.h"
#include "buffer.h"
#include "zlib.h"
+#include "compress.h"
-static z_stream incoming_stream;
-static z_stream outgoing_stream;
+z_stream incoming_stream;
+z_stream outgoing_stream;
+static int compress_init_send_called = 0;
+static int compress_init_recv_called = 0;
+static int inflate_failed = 0;
+static int deflate_failed = 0;
/*
* Initializes compression; level is compression level from 1 to 9
* (as in gzip).
*/
-void
-buffer_compress_init(int level)
+void
+buffer_compress_init_send(int level)
{
+ if (compress_init_send_called == 1)
+ deflateEnd(&outgoing_stream);
+ compress_init_send_called = 1;
debug("Enabling compression at level %d.", level);
if (level < 1 || level > 9)
fatal("Bad compression level %d.", level);
- inflateInit(&incoming_stream);
deflateInit(&outgoing_stream, level);
}
+void
+buffer_compress_init_recv(void)
+{
+ if (compress_init_recv_called == 1)
+ inflateEnd(&incoming_stream);
+ compress_init_recv_called = 1;
+ inflateInit(&incoming_stream);
+}
/* Frees any data structures allocated for compression. */
-void
-buffer_compress_uninit()
+void
+buffer_compress_uninit(void)
{
debug("compress outgoing: raw data %lu, compressed %lu, factor %.2f",
- outgoing_stream.total_in, outgoing_stream.total_out,
- outgoing_stream.total_in == 0 ? 0.0 :
- (double) outgoing_stream.total_out / outgoing_stream.total_in);
+ outgoing_stream.total_in, outgoing_stream.total_out,
+ outgoing_stream.total_in == 0 ? 0.0 :
+ (double) outgoing_stream.total_out / outgoing_stream.total_in);
debug("compress incoming: raw data %lu, compressed %lu, factor %.2f",
- incoming_stream.total_out, incoming_stream.total_in,
- incoming_stream.total_out == 0 ? 0.0 :
- (double) incoming_stream.total_in / incoming_stream.total_out);
- inflateEnd(&incoming_stream);
- deflateEnd(&outgoing_stream);
+ incoming_stream.total_out, incoming_stream.total_in,
+ incoming_stream.total_out == 0 ? 0.0 :
+ (double) incoming_stream.total_in / incoming_stream.total_out);
+ if (compress_init_recv_called == 1 && inflate_failed == 0)
+ inflateEnd(&incoming_stream);
+ if (compress_init_send_called == 1 && deflate_failed == 0)
+ deflateEnd(&outgoing_stream);
}
/*
* receiver. This appends the compressed data to the output buffer.
*/
-void
+void
buffer_compress(Buffer * input_buffer, Buffer * output_buffer)
{
- char buf[4096];
+ u_char buf[4096];
int status;
/* This case is not handled below. */
case Z_OK:
/* Append compressed data to output_buffer. */
buffer_append(output_buffer, buf,
- sizeof(buf) - outgoing_stream.avail_out);
+ sizeof(buf) - outgoing_stream.avail_out);
break;
- case Z_STREAM_END:
- fatal("buffer_compress: deflate returned Z_STREAM_END");
- /* NOTREACHED */
- case Z_STREAM_ERROR:
- fatal("buffer_compress: deflate returned Z_STREAM_ERROR");
- /* NOTREACHED */
- case Z_BUF_ERROR:
- fatal("buffer_compress: deflate returned Z_BUF_ERROR");
- /* NOTREACHED */
default:
+ deflate_failed = 1;
fatal("buffer_compress: deflate returned %d", status);
/* NOTREACHED */
}
- }
- while (outgoing_stream.avail_out == 0);
+ } while (outgoing_stream.avail_out == 0);
}
/*
* with that. This appends the uncompressed data to the output buffer.
*/
-void
+void
buffer_uncompress(Buffer * input_buffer, Buffer * output_buffer)
{
- char buf[4096];
+ u_char buf[4096];
int status;
incoming_stream.next_in = buffer_ptr(input_buffer);
incoming_stream.avail_in = buffer_len(input_buffer);
- incoming_stream.next_out = buf;
- incoming_stream.avail_out = sizeof(buf);
-
for (;;) {
+ /* Set up fixed-size output buffer. */
+ incoming_stream.next_out = buf;
+ incoming_stream.avail_out = sizeof(buf);
+
status = inflate(&incoming_stream, Z_PARTIAL_FLUSH);
switch (status) {
case Z_OK:
buffer_append(output_buffer, buf,
- sizeof(buf) - incoming_stream.avail_out);
- incoming_stream.next_out = buf;
- incoming_stream.avail_out = sizeof(buf);
+ sizeof(buf) - incoming_stream.avail_out);
break;
- case Z_STREAM_END:
- fatal("buffer_uncompress: inflate returned Z_STREAM_END");
- /* NOTREACHED */
- case Z_DATA_ERROR:
- fatal("buffer_uncompress: inflate returned Z_DATA_ERROR");
- /* NOTREACHED */
- case Z_STREAM_ERROR:
- fatal("buffer_uncompress: inflate returned Z_STREAM_ERROR");
- /* NOTREACHED */
case Z_BUF_ERROR:
/*
* Comments in zlib.h say that we should keep calling
* be the error that we get.
*/
return;
- case Z_MEM_ERROR:
- fatal("buffer_uncompress: inflate returned Z_MEM_ERROR");
- /* NOTREACHED */
default:
+ inflate_failed = 1;
fatal("buffer_uncompress: inflate returned %d", status);
+ /* NOTREACHED */
}
}
}