ppp: Move the PPP drivers

Move the PPP drivers into drivers/net/ppp/ and make the
necessary Kconfig and Makefile changes.

CC: Paul Mackerras <paulus@samba.org>
CC: Frank Cusack <fcusack@fcusack.com>
CC: Michal Ostrowski <mostrows@speakeasy.net>
CC: Michal Ostrowski <mostrows@earthlink.net>
CC: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 653 insertions, 0 deletions

diff --git a/drivers/net/ppp/ppp_deflate.c b/drivers/net/ppp/ppp_deflate.c
new file mode 100644
index 000000000000..1dbdf82a6dfd
--- /dev/null
+++ b/drivers/net/ppp/ppp_deflate.c
@@ -0,0 +1,653 @@
+/*
+ *  ==FILEVERSION 980319==
+ *
+ * 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/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/string.h>
+
+#include <linux/ppp_defs.h>
+#include <linux/ppp-comp.h>
+
+#include <linux/zlib.h>
+#include <asm/unaligned.h>
+
+/*
+ * 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     *z_comp_alloc(unsigned char *options, int opt_len);
+static void     *z_decomp_alloc(unsigned char *options, int opt_len);
+static void     z_comp_free(void *state);
+static void     z_decomp_free(void *state);
+static int      z_comp_init(void *state, unsigned char *options,
+                                 int opt_len,
+                                 int unit, int hdrlen, int debug);
+static int      z_decomp_init(void *state, unsigned char *options,
+                                   int opt_len,
+                                   int unit, int hdrlen, int mru, int debug);
+static int      z_compress(void *state, unsigned char *rptr,
+                                unsigned char *obuf,
+                                int isize, int osize);
+static void     z_incomp(void *state, unsigned char *ibuf, int icnt);
+static int      z_decompress(void *state, unsigned char *ibuf,
+                                int isize, unsigned char *obuf, int osize);
+static void     z_comp_reset(void *state);
+static void     z_decomp_reset(void *state);
+static void     z_comp_stats(void *state, struct compstat *stats);
+
+/**
+ *      z_comp_free - free the memory used by a compressor
+ *      @arg:   pointer to the private state for the compressor.
+ */
+static void z_comp_free(void *arg)
+{
+        struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+        if (state) {
+                zlib_deflateEnd(&state->strm);
+                vfree(state->strm.workspace);
+                kfree(state);
+        }
+}
+
+/**
+ *      z_comp_alloc - allocate space for a compressor.
+ *      @options: pointer to CCP option data
+ *      @opt_len: length of the CCP option at @options.
+ *
+ *      The @options pointer points to the a buffer containing the
+ *      CCP option data for the compression being negotiated.  It is
+ *      formatted according to RFC1979, and describes the window
+ *      size that the peer is requesting that we use in compressing
+ *      data to be sent to it.
+ *
+ *      Returns the pointer to the private state for the compressor,
+ *      or NULL if we could not allocate enough memory.
+ */
+static void *z_comp_alloc(unsigned char *options, int opt_len)
+{
+        struct ppp_deflate_state *state;
+        int w_size;
+
+        if (opt_len != CILEN_DEFLATE ||
+            (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT) ||
+            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 = kzalloc(sizeof(*state),
+                                                     GFP_KERNEL);
+        if (state == NULL)
+                return NULL;
+
+        state->strm.next_in   = NULL;
+        state->w_size         = w_size;
+        state->strm.workspace = vmalloc(zlib_deflate_workspacesize(-w_size, 8));
+        if (state->strm.workspace == NULL)
+                goto out_free;
+
+        if (zlib_deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION,
+                         DEFLATE_METHOD_VAL, -w_size, 8, Z_DEFAULT_STRATEGY)
+            != Z_OK)
+                goto out_free;
+        return (void *) state;
+
+out_free:
+        z_comp_free(state);
+        return NULL;
+}
+
+/**
+ *      z_comp_init - initialize a previously-allocated compressor.
+ *      @arg:   pointer to the private state for the compressor
+ *      @options: pointer to the CCP option data describing the
+ *              compression that was negotiated with the peer
+ *      @opt_len: length of the CCP option data at @options
+ *      @unit:  PPP unit number for diagnostic messages
+ *      @hdrlen: ignored (present for backwards compatibility)
+ *      @debug: debug flag; if non-zero, debug messages are printed.
+ *
+ *      The CCP options described by @options must match the options
+ *      specified when the compressor was allocated.  The compressor
+ *      history is reset.  Returns 0 for failure (CCP options don't
+ *      match) or 1 for success.
+ */
+static int z_comp_init(void *arg, unsigned char *options, int opt_len,
+                       int unit, int hdrlen, int debug)
+{
+        struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+        if (opt_len < CILEN_DEFLATE ||
+            (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT) ||
+            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;
+
+        zlib_deflateReset(&state->strm);
+
+        return 1;
+}
+
+/**
+ *      z_comp_reset - reset a previously-allocated compressor.
+ *      @arg:   pointer to private state for the compressor.
+ *
+ *      This clears the history for the compressor and makes it
+ *      ready to start emitting a new compressed stream.
+ */
+static void z_comp_reset(void *arg)
+{
+        struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+        state->seqno = 0;
+        zlib_deflateReset(&state->strm);
+}
+
+/**
+ *      z_compress - compress a PPP packet with Deflate compression.
+ *      @arg:   pointer to private state for the compressor
+ *      @rptr:  uncompressed packet (input)
+ *      @obuf:  compressed packet (output)
+ *      @isize: size of uncompressed packet
+ *      @osize: space available at @obuf
+ *
+ *      Returns the length of the compressed packet, or 0 if the
+ *      packet is incompressible.
+ */
+static int z_compress(void *arg, unsigned char *rptr, unsigned char *obuf,
+               int isize, int osize)
+{
+        struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+        int r, proto, off, olen, oavail;
+        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);
+        put_unaligned_be16(PPP_COMP, wptr + 2);
+        wptr += PPP_HDRLEN;
+        put_unaligned_be16(state->seqno, wptr);
+        wptr += DEFLATE_OVHD;
+        olen = PPP_HDRLEN + DEFLATE_OVHD;
+        state->strm.next_out = wptr;
+        state->strm.avail_out = oavail = osize - olen;
+        ++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);
+
+        for (;;) {
+                r = zlib_deflate(&state->strm, Z_PACKET_FLUSH);
+                if (r != Z_OK) {
+                        if (state->debug)
+                                printk(KERN_ERR
+                                       "z_compress: deflate returned %d\n", r);
+                        break;
+                }
+                if (state->strm.avail_out == 0) {
+                        olen += oavail;
+                        state->strm.next_out = NULL;
+                        state->strm.avail_out = oavail = 1000000;
+                } else {
+                        break;          /* all done */
+                }
+        }
+        olen += oavail - 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;
+}
+
+/**
+ *      z_comp_stats - return compression statistics for a compressor
+ *              or decompressor.
+ *      @arg:   pointer to private space for the (de)compressor
+ *      @stats: pointer to a struct compstat to receive the result.
+ */
+static void z_comp_stats(void *arg, struct compstat *stats)
+{
+        struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+        *stats = state->stats;
+}
+
+/**
+ *      z_decomp_free - Free the memory used by a decompressor.
+ *      @arg:   pointer to private space for the decompressor.
+ */
+static void z_decomp_free(void *arg)
+{
+        struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+        if (state) {
+                zlib_inflateEnd(&state->strm);
+                vfree(state->strm.workspace);
+                kfree(state);
+        }
+}
+
+/**
+ *      z_decomp_alloc - allocate space for a decompressor.
+ *      @options: pointer to CCP option data
+ *      @opt_len: length of the CCP option at @options.
+ *
+ *      The @options pointer points to the a buffer containing the
+ *      CCP option data for the compression being negotiated.  It is
+ *      formatted according to RFC1979, and describes the window
+ *      size that we are requesting the peer to use in compressing
+ *      data to be sent to us.
+ *
+ *      Returns the pointer to the private state for the decompressor,
+ *      or NULL if we could not allocate enough memory.
+ */
+static void *z_decomp_alloc(unsigned char *options, int opt_len)
+{
+        struct ppp_deflate_state *state;
+        int w_size;
+
+        if (opt_len != CILEN_DEFLATE ||
+            (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT) ||
+            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 = kzalloc(sizeof(*state), GFP_KERNEL);
+        if (state == NULL)
+                return NULL;
+
+        state->w_size         = w_size;
+        state->strm.next_out  = NULL;
+        state->strm.workspace = vmalloc(zlib_inflate_workspacesize());
+        if (state->strm.workspace == NULL)
+                goto out_free;
+
+        if (zlib_inflateInit2(&state->strm, -w_size) != Z_OK)
+                goto out_free;
+        return (void *) state;
+
+out_free:
+        z_decomp_free(state);
+        return NULL;
+}
+
+/**
+ *      z_decomp_init - initialize a previously-allocated decompressor.
+ *      @arg:   pointer to the private state for the decompressor
+ *      @options: pointer to the CCP option data describing the
+ *              compression that was negotiated with the peer
+ *      @opt_len: length of the CCP option data at @options
+ *      @unit:  PPP unit number for diagnostic messages
+ *      @hdrlen: ignored (present for backwards compatibility)
+ *      @mru:   maximum length of decompressed packets
+ *      @debug: debug flag; if non-zero, debug messages are printed.
+ *
+ *      The CCP options described by @options must match the options
+ *      specified when the decompressor was allocated.  The decompressor
+ *      history is reset.  Returns 0 for failure (CCP options don't
+ *      match) or 1 for success.
+ */
+static int z_decomp_init(void *arg, unsigned char *options, int opt_len,
+                         int unit, int hdrlen, int mru, int debug)
+{
+        struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+        if (opt_len < CILEN_DEFLATE ||
+            (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT) ||
+            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;
+
+        zlib_inflateReset(&state->strm);
+
+        return 1;
+}
+
+/**
+ *      z_decomp_reset - reset a previously-allocated decompressor.
+ *      @arg:   pointer to private state for the decompressor.
+ *
+ *      This clears the history for the decompressor and makes it
+ *      ready to receive a new compressed stream.
+ */
+static void z_decomp_reset(void *arg)
+{
+        struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
+
+        state->seqno = 0;
+        zlib_inflateReset(&state->strm);
+}
+
+/**
+ *      z_decompress - decompress a Deflate-compressed packet.
+ *      @arg:   pointer to private state for the decompressor
+ *      @ibuf:  pointer to input (compressed) packet data
+ *      @isize: length of input packet
+ *      @obuf:  pointer to space for output (decompressed) packet
+ *      @osize: amount of space available at @obuf
+ *
+ * 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.
+ */
+static int z_decompress(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 = get_unaligned_be16(ibuf + PPP_HDRLEN);
+        if (seq != (state->seqno & 0xffff)) {
+                if (state->debug)
+                        printk(KERN_DEBUG "z_decompress%d: bad seq # %d, expected %d\n",
+                               state->unit, seq, state->seqno & 0xffff);
+                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 = zlib_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) {
+                if (state->debug)
+                        printk(KERN_DEBUG "z_decompress%d: didn't get proto\n",
+                               state->unit);
+                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;
+}
+
+/**
+ *      z_incomp - add incompressible input data to the history.
+ *      @arg:   pointer to private state for the decompressor
+ *      @ibuf:  pointer to input packet data
+ *      @icnt:  length of input data.
+ */
+static void z_incomp(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 = zlib_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_generic.c */
+extern int  ppp_register_compressor   (struct compressor *cp);
+extern void ppp_unregister_compressor (struct compressor *cp);
+
+/*
+ * Procedures exported to if_ppp.c.
+ */
+static struct compressor ppp_deflate = {
+        .compress_proto =       CI_DEFLATE,
+        .comp_alloc =           z_comp_alloc,
+        .comp_free =            z_comp_free,
+        .comp_init =            z_comp_init,
+        .comp_reset =           z_comp_reset,
+        .compress =             z_compress,
+        .comp_stat =            z_comp_stats,
+        .decomp_alloc =         z_decomp_alloc,
+        .decomp_free =          z_decomp_free,
+        .decomp_init =          z_decomp_init,
+        .decomp_reset =         z_decomp_reset,
+        .decompress =           z_decompress,
+        .incomp =               z_incomp,
+        .decomp_stat =          z_comp_stats,
+        .owner =                THIS_MODULE
+};
+
+static struct compressor ppp_deflate_draft = {
+        .compress_proto =       CI_DEFLATE_DRAFT,
+        .comp_alloc =           z_comp_alloc,
+        .comp_free =            z_comp_free,
+        .comp_init =            z_comp_init,
+        .comp_reset =           z_comp_reset,
+        .compress =             z_compress,
+        .comp_stat =            z_comp_stats,
+        .decomp_alloc =         z_decomp_alloc,
+        .decomp_free =          z_decomp_free,
+        .decomp_init =          z_decomp_init,
+        .decomp_reset =         z_decomp_reset,
+        .decompress =           z_decompress,
+        .incomp =               z_incomp,
+        .decomp_stat =          z_comp_stats,
+        .owner =                THIS_MODULE
+};
+
+static int __init deflate_init(void)
+{
+        int answer = ppp_register_compressor(&ppp_deflate);
+        if (answer == 0)
+                printk(KERN_INFO
+                       "PPP Deflate Compression module registered\n");
+        ppp_register_compressor(&ppp_deflate_draft);
+        return answer;
+}
+
+static void __exit deflate_cleanup(void)
+{
+        ppp_unregister_compressor(&ppp_deflate);
+        ppp_unregister_compressor(&ppp_deflate_draft);
+}
+
+module_init(deflate_init);
+module_exit(deflate_cleanup);
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("ppp-compress-" __stringify(CI_DEFLATE));
+MODULE_ALIAS("ppp-compress-" __stringify(CI_DEFLATE_DRAFT));