patch-2.1.67 linux/drivers/net/ppp_deflate.c

• Lines: 661
• Date: Sat Nov 29 10:33:20 1997
• Orig file: v2.1.66/linux/drivers/net/ppp_deflate.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.66/linux/drivers/net/ppp_deflate.c linux/drivers/net/ppp_deflate.c
@@ -0,0 +1,660 @@
+/*
+ *  ==FILEVERSION 971001==
+ *
+ * ppp_deflate.c - interface the zlib procedures for Deflate compression
+ * and decompression (as used by gzip) to the PPP code.
+ * This version is for use with Linux kernel 1.3.X.
+ *
+ * Copyright (c) 1994 The Australian National University.
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation is hereby granted, provided that the above copyright
+ * notice appears in all copies.  This software is provided without any
+ * warranty, express or implied. The Australian National University
+ * makes no representations about the suitability of this software for
+ * any purpose.
+ *
+ * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
+ * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
+ * THE AUSTRALIAN NATIONAL UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
+ * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
+ * OR MODIFICATIONS.
+ *
+ * From: deflate.c,v 1.1 1996/01/18 03:17:48 paulus Exp
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/in.h>
+#include <linux/malloc.h>
+#include <linux/vmalloc.h>
+#include <linux/errno.h>
+#include <linux/sched.h>	/* to get the struct task_struct */
+#include <linux/string.h>	/* used in new tty drivers */
+#include <linux/signal.h>	/* used in new tty drivers */
+
+#include <asm/system.h>
+
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/inet.h>
+#include <linux/ioctl.h>
+
+#include <linux/ppp_defs.h>
+
+#undef	 PACKETPTR
+#define	 PACKETPTR 1
+#include <linux/ppp-comp.h>
+#undef	 PACKETPTR
+
+#include "zlib.c"
+
+/*
+ * State for a Deflate (de)compressor.
+ */
+struct ppp_deflate_state {
+    int		seqno;
+    int		w_size;
+    int		unit;
+    int		mru;
+    int		debug;
+    z_stream	strm;
+    struct compstat stats;
+};
+
+#define DEFLATE_OVHD	2		/* Deflate overhead/packet */
+
+static void	*zalloc __P((void *, unsigned int items, unsigned int size));
+static void	*zalloc_init __P((void *, unsigned int items,
+				  unsigned int size));
+static void	zfree __P((void *, void *ptr));
+static void	*z_comp_alloc __P((unsigned char *options, int opt_len));
+static void	*z_decomp_alloc __P((unsigned char *options, int opt_len));
+static void	z_comp_free __P((void *state));
+static void	z_decomp_free __P((void *state));
+static int	z_comp_init __P((void *state, unsigned char *options,
+				 int opt_len,
+				 int unit, int hdrlen, int debug));
+static int	z_decomp_init __P((void *state, unsigned char *options,
+				   int opt_len,
+				   int unit, int hdrlen, int mru, int debug));
+static int	z_compress __P((void *state, unsigned char *rptr,
+				unsigned char *obuf,
+				int isize, int osize));
+static void	z_incomp __P((void *state, unsigned char *ibuf, int icnt));
+static int	z_decompress __P((void *state, unsigned char *ibuf,
+				int isize, unsigned char *obuf, int osize));
+static void	z_comp_reset __P((void *state));
+static void	z_decomp_reset __P((void *state));
+static void	z_comp_stats __P((void *state, struct compstat *stats));
+
+struct chunk_header {
+	int valloced;		/* allocated with valloc, not kmalloc */
+	int guard;		/* check for overwritten header */
+};
+
+#define GUARD_MAGIC	0x77a8011a
+#define MIN_VMALLOC	2048	/* use kmalloc for blocks < this */
+
+/*
+ * Space allocation and freeing routines for use by zlib routines.
+ */
+void
+zfree(arg, ptr)
+    void *arg;
+    void *ptr;
+{
+	struct chunk_header *hdr = ((struct chunk_header *)ptr) - 1;
+
+	if (hdr->guard != GUARD_MAGIC) {
+		printk(KERN_WARNING "zfree: header corrupted (%x %x) at %p\n",
+		       hdr->valloced, hdr->guard, hdr);
+		return;
+	}
+	if (hdr->valloced)
+		vfree(hdr);
+	else
+		kfree(hdr);
+}
+
+void *
+zalloc(arg, items, size)
+    void *arg;
+    unsigned int items, size;
+{
+	struct chunk_header *hdr;
+	unsigned nbytes;
+
+	nbytes = items * size + sizeof(*hdr);
+	hdr = kmalloc(nbytes, GFP_ATOMIC);
+	if (hdr == 0)
+		return 0;
+	hdr->valloced = 0;
+	hdr->guard = GUARD_MAGIC;
+	return (void *) (hdr + 1);
+}
+
+void *
+zalloc_init(arg, items, size)
+    void *arg;
+    unsigned int items, size;
+{
+	struct chunk_header *hdr;
+	unsigned nbytes;
+
+	nbytes = items * size + sizeof(*hdr);
+	if (nbytes >= MIN_VMALLOC)
+		hdr = vmalloc(nbytes);
+	else
+		hdr = kmalloc(nbytes, GFP_KERNEL);
+	if (hdr == 0)
+		return 0;
+	hdr->valloced = nbytes >= MIN_VMALLOC;
+	hdr->guard = GUARD_MAGIC;
+	return (void *) (hdr + 1);
+}
+
+static void
+z_comp_free(arg)
+    void *arg;
+{
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+	if (state) {
+		deflateEnd(&state->strm);
+		kfree(state);
+		MOD_DEC_USE_COUNT;
+	}
+}
+
+/*
+ * Allocate space for a compressor.
+ */
+static void *
+z_comp_alloc(options, opt_len)
+    unsigned char *options;
+    int opt_len;
+{
+	struct ppp_deflate_state *state;
+	int w_size;
+
+	if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE
+	    || options[1] != CILEN_DEFLATE
+	    || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
+	    || options[3] != DEFLATE_CHK_SEQUENCE)
+		return NULL;
+	w_size = DEFLATE_SIZE(options[2]);
+	if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
+		return NULL;
+
+	state = (struct ppp_deflate_state *) kmalloc(sizeof(*state), GFP_KERNEL);
+	if (state == NULL)
+		return NULL;
+
+	MOD_INC_USE_COUNT;
+	memset (state, 0, sizeof (struct ppp_deflate_state));
+	state->strm.next_in = NULL;
+	state->strm.zalloc  = zalloc_init;
+	state->strm.zfree   = zfree;
+	state->w_size       = w_size;
+
+	if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION,
+			 DEFLATE_METHOD_VAL, -w_size, 8, Z_DEFAULT_STRATEGY)
+	    != Z_OK) {
+		z_comp_free(state);
+		return NULL;
+	}
+
+	state->strm.zalloc = zalloc;
+	return (void *) state;
+}
+
+static int
+z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
+    void *arg;
+    unsigned char *options;
+    int opt_len, unit, hdrlen, debug;
+{
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+	if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE
+	    || options[1] != CILEN_DEFLATE
+	    || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
+	    || DEFLATE_SIZE(options[2]) != state->w_size
+	    || options[3] != DEFLATE_CHK_SEQUENCE)
+		return 0;
+
+	state->seqno = 0;
+	state->unit  = unit;
+	state->debug = debug;
+
+	deflateReset(&state->strm);
+
+	return 1;
+}
+
+static void
+z_comp_reset(arg)
+    void *arg;
+{
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+	state->seqno = 0;
+	deflateReset(&state->strm);
+}
+
+int
+z_compress(arg, rptr, obuf, isize, osize)
+    void *arg;
+    unsigned char *rptr;	/* uncompressed packet (in) */
+    unsigned char *obuf;	/* compressed packet (out) */
+    int isize, osize;
+{
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+	int r, proto, off, olen;
+	unsigned char *wptr;
+
+	/*
+	 * Check that the protocol is in the range we handle.
+	 */
+	proto = PPP_PROTOCOL(rptr);
+	if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
+		return 0;
+
+	/* Don't generate compressed packets which are larger than
+	   the uncompressed packet. */
+	if (osize > isize)
+		osize = isize;
+
+	wptr = obuf;
+
+	/*
+	 * Copy over the PPP header and store the 2-byte sequence number.
+	 */
+	wptr[0] = PPP_ADDRESS(rptr);
+	wptr[1] = PPP_CONTROL(rptr);
+	wptr[2] = PPP_COMP >> 8;
+	wptr[3] = PPP_COMP;
+	wptr += PPP_HDRLEN;
+	wptr[0] = state->seqno >> 8;
+	wptr[1] = state->seqno;
+	wptr += 2;
+	state->strm.next_out = wptr;
+	state->strm.avail_out = osize - (PPP_HDRLEN + 2);
+	++state->seqno;
+
+	off = (proto > 0xff) ? 2 : 3;	/* skip 1st proto byte if 0 */
+	rptr += off;
+	state->strm.next_in = rptr;
+	state->strm.avail_in = (isize - off);
+
+	olen = 0;
+	for (;;) {
+		r = deflate(&state->strm, Z_PACKET_FLUSH);
+		if (r != Z_OK) {
+			if (state->debug)
+				printk(KERN_DEBUG "z_compress: deflate returned %d (%s)\n",
+				       r, (state->strm.msg? state->strm.msg: ""));
+			break;
+		}
+		if (state->strm.avail_out == 0) {
+			olen += osize;
+			state->strm.next_out = NULL;
+			state->strm.avail_out = 1000000;
+		} else {
+			break;		/* all done */
+		}
+	}
+	if (olen < osize)
+		olen += osize - state->strm.avail_out;
+
+	/*
+	 * See if we managed to reduce the size of the packet.
+	 */
+	if (olen < isize) {
+		state->stats.comp_bytes += olen;
+		state->stats.comp_packets++;
+	} else {
+		state->stats.inc_bytes += isize;
+		state->stats.inc_packets++;
+		olen = 0;
+	}
+	state->stats.unc_bytes += isize;
+	state->stats.unc_packets++;
+
+	return olen;
+}
+
+static void
+z_comp_stats(arg, stats)
+    void *arg;
+    struct compstat *stats;
+{
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+	*stats = state->stats;
+}
+
+static void
+z_decomp_free(arg)
+    void *arg;
+{
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+	if (state) {
+		inflateEnd(&state->strm);
+		kfree(state);
+		MOD_DEC_USE_COUNT;
+	}
+}
+
+/*
+ * Allocate space for a decompressor.
+ */
+static void *
+z_decomp_alloc(options, opt_len)
+    unsigned char *options;
+    int opt_len;
+{
+	struct ppp_deflate_state *state;
+	int w_size;
+
+	if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE
+	    || options[1] != CILEN_DEFLATE
+	    || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
+	    || options[3] != DEFLATE_CHK_SEQUENCE)
+		return NULL;
+	w_size = DEFLATE_SIZE(options[2]);
+	if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
+		return NULL;
+
+	state = (struct ppp_deflate_state *) kmalloc(sizeof(*state), GFP_KERNEL);
+	if (state == NULL)
+		return NULL;
+
+	MOD_INC_USE_COUNT;
+	memset (state, 0, sizeof (struct ppp_deflate_state));
+	state->w_size        = w_size;
+	state->strm.next_out = NULL;
+	state->strm.zalloc   = zalloc_init;
+	state->strm.zfree    = zfree;
+
+	if (inflateInit2(&state->strm, -w_size) != Z_OK) {
+		z_decomp_free(state);
+		return NULL;
+	}
+
+	state->strm.zalloc = zalloc;
+	return (void *) state;
+}
+
+static int
+z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
+    void *arg;
+    unsigned char *options;
+    int opt_len, unit, hdrlen, mru, debug;
+{
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+	if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE
+	    || options[1] != CILEN_DEFLATE
+	    || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
+	    || DEFLATE_SIZE(options[2]) != state->w_size
+	    || options[3] != DEFLATE_CHK_SEQUENCE)
+		return 0;
+
+	state->seqno = 0;
+	state->unit  = unit;
+	state->debug = debug;
+	state->mru   = mru;
+
+	inflateReset(&state->strm);
+
+	return 1;
+}
+
+static void
+z_decomp_reset(arg)
+    void *arg;
+{
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+	state->seqno = 0;
+	inflateReset(&state->strm);
+}
+
+/*
+ * Decompress a Deflate-compressed packet.
+ *
+ * Because of patent problems, we return DECOMP_ERROR for errors
+ * found by inspecting the input data and for system problems, but
+ * DECOMP_FATALERROR for any errors which could possibly be said to
+ * be being detected "after" decompression.  For DECOMP_ERROR,
+ * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
+ * infringing a patent of Motorola's if we do, so we take CCP down
+ * instead.
+ *
+ * Given that the frame has the correct sequence number and a good FCS,
+ * errors such as invalid codes in the input most likely indicate a
+ * bug, so we return DECOMP_FATALERROR for them in order to turn off
+ * compression, even though they are detected by inspecting the input.
+ */
+int
+z_decompress(arg, ibuf, isize, obuf, osize)
+    void *arg;
+    unsigned char *ibuf;
+    int isize;
+    unsigned char *obuf;
+    int osize;
+{
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+	int olen, seq, r;
+	int decode_proto, overflow;
+	unsigned char overflow_buf[1];
+
+	if (isize <= PPP_HDRLEN + DEFLATE_OVHD) {
+		if (state->debug)
+			printk(KERN_DEBUG "z_decompress%d: short pkt (%d)\n",
+			       state->unit, isize);
+		return DECOMP_ERROR;
+	}
+
+	/* Check the sequence number. */
+	seq = (ibuf[PPP_HDRLEN] << 8) + ibuf[PPP_HDRLEN+1];
+	if (seq != state->seqno) {
+		if (state->debug)
+			printk(KERN_DEBUG "z_decompress%d: bad seq # %d, expected %d\n",
+			       state->unit, seq, state->seqno);
+		return DECOMP_ERROR;
+	}
+	++state->seqno;
+
+	/*
+	 * Fill in the first part of the PPP header.  The protocol field
+	 * comes from the decompressed data.
+	 */
+	obuf[0] = PPP_ADDRESS(ibuf);
+	obuf[1] = PPP_CONTROL(ibuf);
+	obuf[2] = 0;
+
+	/*
+	 * Set up to call inflate.  We set avail_out to 1 initially so we can
+	 * look at the first byte of the output and decide whether we have
+	 * a 1-byte or 2-byte protocol field.
+	 */
+	state->strm.next_in = ibuf + PPP_HDRLEN + DEFLATE_OVHD;
+	state->strm.avail_in = isize - (PPP_HDRLEN + DEFLATE_OVHD);
+	state->strm.next_out = obuf + 3;
+	state->strm.avail_out = 1;
+	decode_proto = 1;
+	overflow = 0;
+
+	/*
+	 * Call inflate, supplying more input or output as needed.
+	 */
+	for (;;) {
+		r = inflate(&state->strm, Z_PACKET_FLUSH);
+		if (r != Z_OK) {
+			if (state->debug)
+				printk(KERN_DEBUG "z_decompress%d: inflate returned %d (%s)\n",
+				       state->unit, r, (state->strm.msg? state->strm.msg: ""));
+			return DECOMP_FATALERROR;
+		}
+		if (state->strm.avail_out != 0)
+			break;		/* all done */
+		if (decode_proto) {
+			state->strm.avail_out = osize - PPP_HDRLEN;
+			if ((obuf[3] & 1) == 0) {
+				/* 2-byte protocol field */
+				obuf[2] = obuf[3];
+				--state->strm.next_out;
+				++state->strm.avail_out;
+			}
+			decode_proto = 0;
+		} else if (!overflow) {
+			/*
+			 * We've filled up the output buffer; the only way to
+			 * find out whether inflate has any more characters
+			 * left is to give it another byte of output space.
+			 */
+			state->strm.next_out = overflow_buf;
+			state->strm.avail_out = 1;
+			overflow = 1;
+		} else {
+			if (state->debug)
+				printk(KERN_DEBUG "z_decompress%d: ran out of mru\n",
+				       state->unit);
+			return DECOMP_FATALERROR;
+		}
+	}
+
+	if (decode_proto)
+		return DECOMP_ERROR;
+
+	olen = osize + overflow - state->strm.avail_out;
+	state->stats.unc_bytes += olen;
+	state->stats.unc_packets++;
+	state->stats.comp_bytes += isize;
+	state->stats.comp_packets++;
+
+	return olen;
+}
+
+/*
+ * Incompressible data has arrived - add it to the history.
+ */
+static void
+z_incomp(arg, ibuf, icnt)
+    void *arg;
+    unsigned char *ibuf;
+    int icnt;
+{
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+	int proto, r;
+
+	/*
+	 * Check that the protocol is one we handle.
+	 */
+	proto = PPP_PROTOCOL(ibuf);
+	if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
+		return;
+
+	++state->seqno;
+
+	/*
+	 * We start at the either the 1st or 2nd byte of the protocol field,
+	 * depending on whether the protocol value is compressible.
+	 */
+	state->strm.next_in = ibuf + 3;
+	state->strm.avail_in = icnt - 3;
+	if (proto > 0xff) {
+		--state->strm.next_in;
+		++state->strm.avail_in;
+	}
+
+	r = inflateIncomp(&state->strm);
+	if (r != Z_OK) {
+		/* gak! */
+		if (state->debug) {
+			printk(KERN_DEBUG "z_incomp%d: inflateIncomp returned %d (%s)\n",
+			       state->unit, r, (state->strm.msg? state->strm.msg: ""));
+		}
+		return;
+	}
+
+	/*
+	 * Update stats.
+	 */
+	state->stats.inc_bytes += icnt;
+	state->stats.inc_packets++;
+	state->stats.unc_bytes += icnt;
+	state->stats.unc_packets++;
+}
+
+/*************************************************************
+ * Module interface table
+ *************************************************************/
+
+/* These are in ppp.c */
+extern int  ppp_register_compressor   (struct compressor *cp);
+extern void ppp_unregister_compressor (struct compressor *cp);
+
+/*
+ * Procedures exported to if_ppp.c.
+ */
+struct compressor ppp_deflate = {
+	CI_DEFLATE,		/* compress_proto */
+	z_comp_alloc,		/* comp_alloc */
+	z_comp_free,		/* comp_free */
+	z_comp_init,		/* comp_init */
+	z_comp_reset,		/* comp_reset */
+	z_compress,		/* compress */
+	z_comp_stats,		/* comp_stat */
+	z_decomp_alloc,		/* decomp_alloc */
+	z_decomp_free,		/* decomp_free */
+	z_decomp_init,		/* decomp_init */
+	z_decomp_reset,		/* decomp_reset */
+	z_decompress,		/* decompress */
+	z_incomp,		/* incomp */
+	z_comp_stats,		/* decomp_stat */
+};
+
+#ifdef MODULE
+/*************************************************************
+ * Module support routines
+ *************************************************************/
+
+int
+init_module(void)
+{  
+        int answer = ppp_register_compressor (&ppp_deflate);
+        if (answer == 0)
+                printk (KERN_INFO
+			"PPP Deflate Compression module registered\n");
+        return answer;
+}
+     
+void
+cleanup_module(void)
+{
+	if (MOD_IN_USE)
+		printk (KERN_INFO
+			"Deflate Compression module busy, remove delayed\n");
+	else
+	        ppp_unregister_compressor (&ppp_deflate);
+}
+#endif