X-Git-Url: http://git.ozlabs.org/?p=ppp.git;a=blobdiff_plain;f=linux%2Fppp_deflate.c;h=bd2234277475917e6a73f2206356f482e5050104;hp=3de45971c6fbe70bf288740242d705afd4de16d0;hb=6df1318f7c7c2afa76293e90671aac884488a19d;hpb=1d80f42e7fee2db352e176d52219bf42e11d2eb4

diff --git a/linux/ppp_deflate.c b/linux/ppp_deflate.c
index 3de4597..bd22342 100644
--- a/linux/ppp_deflate.c
+++ b/linux/ppp_deflate.c
@@ -1,5 +1,5 @@
 /*
- *  ==FILEVERSION 970522==
+ *  ==FILEVERSION 971001==
  *
  * ppp_deflate.c - interface the zlib procedures for Deflate compression
  * and decompression (as used by gzip) to the PPP code.
@@ -86,7 +86,7 @@ struct ppp_deflate_state {
 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, unsigned int nb));
+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));
@@ -108,27 +108,32 @@ static void	z_decomp_reset __P((void *state));
 static void	z_comp_stats __P((void *state, struct compstat *stats));
 
 struct chunk_header {
-    unsigned size;		/* amount of space following header */
-    int valloced;		/* allocated with valloc, not kmalloc */
+	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, nbytes)
+zfree(arg, ptr)
     void *arg;
     void *ptr;
-    unsigned int nbytes;
 {
-    struct chunk_header *hdr = ((struct chunk_header *)ptr) - 1;
+	struct chunk_header *hdr = ((struct chunk_header *)ptr) - 1;
 
-    if (hdr->valloced)
-	vfree(hdr);
-    else
-	kfree(hdr);
+	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 *
@@ -136,16 +141,16 @@ 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->size = nbytes;
-    hdr->valloced = 0;
-    return (void *) (hdr + 1);
+	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 *
@@ -153,32 +158,32 @@ 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->size = nbytes;
-    hdr->valloced = nbytes >= MIN_VMALLOC;
-    return (void *) (hdr + 1);
+	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;
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 
-    if (state) {
-	    deflateEnd(&state->strm);
-	    kfree(state);
-	    MOD_DEC_USE_COUNT;
-    }
+	if (state) {
+		deflateEnd(&state->strm);
+		kfree(state);
+		MOD_DEC_USE_COUNT;
+	}
 }
 
 /*
@@ -189,36 +194,38 @@ 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;
-    state->strm.zalloc_init = 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, DEFLATE_OVHD+2) != Z_OK) {
-	z_comp_free(state);
-	return NULL;
-    }
-    return (void *) state;
+	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
@@ -227,32 +234,32 @@ z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
     unsigned char *options;
     int opt_len, unit, hdrlen, debug;
 {
-    struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+	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;
+	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->seqno = 0;
+	state->unit  = unit;
+	state->debug = debug;
 
-    deflateReset(&state->strm);
+	deflateReset(&state->strm);
 
-    return 1;
+	return 1;
 }
 
 static void
 z_comp_reset(arg)
     void *arg;
 {
-    struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 
-    state->seqno = 0;
-    deflateReset(&state->strm);
+	state->seqno = 0;
+	deflateReset(&state->strm);
 }
 
 int
@@ -262,81 +269,79 @@ z_compress(arg, rptr, obuf, isize, osize)
     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;
+	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 (state->strm.avail_out == 0) {
-	    olen += osize;
-	    state->strm.next_out = NULL;
-	    state->strm.avail_out = 1000000;
+	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 {
-	    break;		/* all done */
+		state->stats.inc_bytes += isize;
+		state->stats.inc_packets++;
+		olen = 0;
 	}
-    }
-    if (olen < osize)
-	olen += osize - state->strm.avail_out;
-
-    /*
-     * See if we managed to reduce the size of the packet.
-     * If the compressor just gave us a single zero byte, it means
-     * the packet was incompressible.
-     */
-    if (olen < isize && !(olen == PPP_HDRLEN + 3 && *wptr == 0)) {
-	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++;
+	state->stats.unc_bytes += isize;
+	state->stats.unc_packets++;
 
-    return olen;
+	return olen;
 }
 
 static void
@@ -344,25 +349,22 @@ z_comp_stats(arg, stats)
     void *arg;
     struct compstat *stats;
 {
-    struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 
-    *stats = state->stats;
+	*stats = state->stats;
 }
 
 static void
 z_decomp_free(arg)
     void *arg;
 {
-    struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 
-    if (state) {
-	    inflateEnd(&state->strm);
-#if USEMEMPOOL
-	    memPoolFree(&state->strm.opaque);
-#endif
-	    kfree(state);
-	    MOD_DEC_USE_COUNT;
-    }
+	if (state) {
+		inflateEnd(&state->strm);
+		kfree(state);
+		MOD_DEC_USE_COUNT;
+	}
 }
 
 /*
@@ -373,35 +375,36 @@ 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;
-    state->strm.zalloc_init = zalloc_init;
-    state->strm.zfree    = zfree;
-
-    if (inflateInit2(&state->strm, -w_size) != Z_OK) {
-	z_decomp_free(state);
-	return NULL;
-    }
-    return (void *) state;
+	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
@@ -410,33 +413,33 @@ z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
     unsigned char *options;
     int opt_len, unit, hdrlen, mru, debug;
 {
-    struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+	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;
+	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;
+	state->seqno = 0;
+	state->unit  = unit;
+	state->debug = debug;
+	state->mru   = mru;
 
-    inflateReset(&state->strm);
+	inflateReset(&state->strm);
 
-    return 1;
+	return 1;
 }
 
 static void
 z_decomp_reset(arg)
     void *arg;
 {
-    struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+	struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 
-    state->seqno = 0;
-    inflateReset(&state->strm);
+	state->seqno = 0;
+	inflateReset(&state->strm);
 }
 
 /*
@@ -463,97 +466,97 @@ z_decompress(arg, ibuf, isize, obuf, osize)
     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 packet (len=%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;
+	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;
 	}
-	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;
+
+	/* 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;
+	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++;
+	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;
+	return olen;
 }
 
 /*
@@ -565,48 +568,46 @@ z_incomp(arg, ibuf, icnt)
     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;
-
-    /*
-     * Iterate through the message blocks, adding the characters in them
-     * to the decompressor's history.  For the first block, 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: ""));
+	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;
 	}
-	return;
-    }
-
-    /*
-     * Update stats.
-     */
-    state->stats.inc_bytes += icnt;
-    state->stats.inc_packets++;
-    state->stats.unc_bytes += icnt;
-    state->stats.unc_packets++;
+
+	/*
+	 * Update stats.
+	 */
+	state->stats.inc_bytes += icnt;
+	state->stats.inc_packets++;
+	state->stats.unc_bytes += icnt;
+	state->stats.unc_packets++;
 }
 
 /*************************************************************
@@ -621,20 +622,20 @@ 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 */
+	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