+/* $OpenBSD: compress.c,v 1.25 2006/08/06 01:13:32 stevesk Exp $ */
/*
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ * All rights reserved
+ * 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".
+ */
-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.
+#include "includes.h"
-*/
+#include <sys/types.h>
-#include "includes.h"
-RCSID("$Id$");
+#include <stdarg.h>
+#include <zlib.h>
-#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). */
+/*
+ * 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)
{
- 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);
+ 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);
+ 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);
- 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);
+ debug("compress outgoing: raw data %llu, compressed %llu, factor %.2f",
+ (unsigned long long)outgoing_stream.total_in,
+ (unsigned long long)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 %llu, compressed %llu, factor %.2f",
+ (unsigned long long)incoming_stream.total_out,
+ (unsigned long long)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);
}
-/* Compresses the contents of input_buffer into output_buffer. All
- packets compressed using this function will form a single
- compressed data stream; however, data will be flushed at the end of
- every call so that each output_buffer can be decompressed
- independently (but in the appropriate order since they together
- form a single compression stream) by the receiver. This appends
- the compressed data to the output buffer. */
-
-void buffer_compress(Buffer *input_buffer, Buffer *output_buffer)
+/*
+ * Compresses the contents of input_buffer into output_buffer. All packets
+ * compressed using this function will form a single compressed data stream;
+ * however, data will be flushed at the end of every call so that each
+ * output_buffer can be decompressed independently (but in the appropriate
+ * order since they together form a single compression stream) by the
+ * receiver. This appends the compressed data to the output buffer.
+ */
+
+void
+buffer_compress(Buffer * input_buffer, Buffer * output_buffer)
{
- char buf[4096];
- int status;
-
- /* This case is not handled below. */
- if (buffer_len(input_buffer) == 0)
- return;
-
- /* Input is the contents of the input buffer. */
- outgoing_stream.next_in = buffer_ptr(input_buffer);
- outgoing_stream.avail_in = buffer_len(input_buffer);
-
- /* Loop compressing until deflate() returns with avail_out != 0. */
- do
- {
- /* Set up fixed-size output buffer. */
- outgoing_stream.next_out = buf;
- outgoing_stream.avail_out = sizeof(buf);
-
- /* Compress as much data into the buffer as possible. */
- status = deflate(&outgoing_stream, Z_PARTIAL_FLUSH);
- switch (status)
- {
- case Z_OK:
- /* Append compressed data to output_buffer. */
- buffer_append(output_buffer, buf,
- 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:
- fatal("buffer_compress: deflate returned %d", status);
- /*NOTREACHED*/
- }
- }
- while (outgoing_stream.avail_out == 0);
+ u_char buf[4096];
+ int status;
+
+ /* This case is not handled below. */
+ if (buffer_len(input_buffer) == 0)
+ return;
+
+ /* Input is the contents of the input buffer. */
+ outgoing_stream.next_in = buffer_ptr(input_buffer);
+ outgoing_stream.avail_in = buffer_len(input_buffer);
+
+ /* Loop compressing until deflate() returns with avail_out != 0. */
+ do {
+ /* Set up fixed-size output buffer. */
+ outgoing_stream.next_out = buf;
+ outgoing_stream.avail_out = sizeof(buf);
+
+ /* Compress as much data into the buffer as possible. */
+ status = deflate(&outgoing_stream, Z_PARTIAL_FLUSH);
+ switch (status) {
+ case Z_OK:
+ /* Append compressed data to output_buffer. */
+ buffer_append(output_buffer, buf,
+ sizeof(buf) - outgoing_stream.avail_out);
+ break;
+ default:
+ deflate_failed = 1;
+ fatal("buffer_compress: deflate returned %d", status);
+ /* NOTREACHED */
+ }
+ } while (outgoing_stream.avail_out == 0);
}
-/* Uncompresses the contents of input_buffer into output_buffer. All
- packets uncompressed using this function will form a single
- compressed data stream; however, data will be flushed at the end of
- every call so that each output_buffer. This must be called for the
- same size units that the buffer_compress was called, and in the
- same order that buffers compressed with that. This appends the
- uncompressed data to the output buffer. */
-
-void buffer_uncompress(Buffer *input_buffer, Buffer *output_buffer)
+/*
+ * Uncompresses the contents of input_buffer into output_buffer. All packets
+ * uncompressed using this function will form a single compressed data
+ * stream; however, data will be flushed at the end of every call so that
+ * each output_buffer. This must be called for the same size units that the
+ * buffer_compress was called, and in the same order that buffers compressed
+ * with that. This appends the uncompressed data to the output buffer.
+ */
+
+void
+buffer_uncompress(Buffer * input_buffer, Buffer * output_buffer)
{
- 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 (;;)
- {
- 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);
- 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 inflate()
- until we get an error. This appears to be the error that we
- get. */
- return;
- case Z_MEM_ERROR:
- fatal("buffer_uncompress: inflate returned Z_MEM_ERROR");
- /*NOTREACHED*/
- default:
- fatal("buffer_uncompress: inflate returned %d", status);
+ u_char buf[4096];
+ int status;
+
+ incoming_stream.next_in = buffer_ptr(input_buffer);
+ incoming_stream.avail_in = buffer_len(input_buffer);
+
+ 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);
+ break;
+ case Z_BUF_ERROR:
+ /*
+ * Comments in zlib.h say that we should keep calling
+ * inflate() until we get an error. This appears to
+ * be the error that we get.
+ */
+ return;
+ default:
+ inflate_failed = 1;
+ fatal("buffer_uncompress: inflate returned %d", status);
+ /* NOTREACHED */
+ }
}
- }
}
-