URL https://opencores.org/ocsvn/or1k/or1k/trunk

Subversion Repositories or1k

[/] [or1k/] [trunk/] [rtems-20020807/] [cpukit/] [libnetworking/] [net/] [ppp-deflate.c] - Blame information for rev 1774

Go to most recent revision | Details | Compare with Previous | View Log


/*      ppp-deflate.c,v 1.1 2002/01/31 21:40:47 joel Exp        */
 
/*
 * 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 mbufs on BSD-derived systems.
 *
 * 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.
 */
 
#include <sys/param.h>
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <net/ppp_defs.h>
#include <net/zlib.h>
 
#define PACKETPTR       struct mbuf *
#include <net/ppp-comp.h>
 
#if DO_DEFLATE
 
#define DEFLATE_DEBUG   1
 
/*
 * State for a Deflate (de)compressor.
 */
struct deflate_state {
    int         seqno;
    int         w_size;
    int         unit;
    int         hdrlen;
    int         mru;
    int         debug;
    z_stream    strm;
    struct compstat stats;
};
 
#define DEFLATE_OVHD    2               /* Deflate overhead/packet */
 
static void     *zalloc __P((void *, u_int items, u_int size));
static void     zfree __P((void *, void *ptr));
static void     *z_comp_alloc __P((u_char *options, int opt_len));
static void     *z_decomp_alloc __P((u_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, u_char *options, int opt_len,
                                 int unit, int hdrlen, int debug));
static int      z_decomp_init __P((void *state, u_char *options, int opt_len,
                                     int unit, int hdrlen, int mru, int debug));
static int      z_compress __P((void *state, struct mbuf **mret,
                                  struct mbuf *mp, int slen, int maxolen));
static void     z_incomp __P((void *state, struct mbuf *dmsg));
static int      z_decompress __P((void *state, struct mbuf *cmp,
                                    struct mbuf **dmpp));
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));
 
/*
 * 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 */
};
 
struct compressor ppp_deflate = {
    CI_DEFLATE_DRAFT,           /* 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 */
};
 
/*
 * Space allocation and freeing routines for use by zlib routines.
 */
void *
zalloc(notused, items, size)
    void *notused;
    u_int items, size;
{
    void *ptr;
 
    MALLOC(ptr, void *, items * size, M_DEVBUF, M_NOWAIT);
    return ptr;
}
 
void
zfree(notused, ptr)
    void *notused;
    void *ptr;
{
    FREE(ptr, M_DEVBUF);
}
 
/*
 * Allocate space for a compressor.
 */
static void *
z_comp_alloc(options, opt_len)
    u_char *options;
    int opt_len;
{
    struct 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;
 
    MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
           M_DEVBUF, M_NOWAIT);
    if (state == NULL)
        return NULL;
 
    state->strm.next_in = NULL;
    state->strm.zalloc = zalloc;
    state->strm.zfree = zfree;
    if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL,
                     -w_size, 8, Z_DEFAULT_STRATEGY) != Z_OK) {
        FREE(state, M_DEVBUF);
        return NULL;
    }
 
    state->w_size = w_size;
    bzero(&state->stats, sizeof(state->stats));
    return (void *) state;
}
 
static void
z_comp_free(arg)
    void *arg;
{
    struct deflate_state *state = (struct deflate_state *) arg;
 
    deflateEnd(&state->strm);
    FREE(state, M_DEVBUF);
}
 
static int
z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
    void *arg;
    u_char *options;
    int opt_len, unit, hdrlen, debug;
{
    struct deflate_state *state = (struct 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->hdrlen = hdrlen;
    state->debug = debug;
 
    deflateReset(&state->strm);
 
    return 1;
}
 
static void
z_comp_reset(arg)
    void *arg;
{
    struct deflate_state *state = (struct deflate_state *) arg;
 
    state->seqno = 0;
    deflateReset(&state->strm);
}
 
int
z_compress(arg, mret, mp, orig_len, maxolen)
    void *arg;
    struct mbuf **mret;         /* compressed packet (out) */
    struct mbuf *mp;            /* uncompressed packet (in) */
    int orig_len, maxolen;
{
    struct deflate_state *state = (struct deflate_state *) arg;
    u_char *rptr, *wptr;
    int proto, olen, wspace, r, flush;
    struct mbuf *m;
 
    /*
     * Check that the protocol is in the range we handle.
     */
    rptr = mtod(mp, u_char *);
    proto = PPP_PROTOCOL(rptr);
    if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) {
        *mret = NULL;
        return orig_len;
    }
 
    /* Allocate one mbuf initially. */
    if (maxolen > orig_len)
        maxolen = orig_len;
    MGET(m, M_DONTWAIT, MT_DATA);
    *mret = m;
    if (m != NULL) {
        m->m_len = 0;
        if (maxolen + state->hdrlen > MLEN)
            MCLGET(m, M_DONTWAIT);
        wspace = M_TRAILINGSPACE(m);
        if (state->hdrlen + PPP_HDRLEN + 2 < wspace) {
            m->m_data += state->hdrlen;
            wspace -= state->hdrlen;
        }
        wptr = mtod(m, u_char *);
 
        /*
         * 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 = wspace - (PPP_HDRLEN + 2);
    } else {
        state->strm.next_out = NULL;
        state->strm.avail_out = 1000000;
        wptr = NULL;
        wspace = 0;
    }
    ++state->seqno;
 
    rptr += (proto > 0xff)? 2: 3;       /* skip 1st proto byte if 0 */
    state->strm.next_in = rptr;
    state->strm.avail_in = mtod(mp, u_char *) + mp->m_len - rptr;
    mp = mp->m_next;
    flush = (mp == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
    olen = 0;
    for (;;) {
        r = deflate(&state->strm, flush);
        if (r != Z_OK) {
            printf("z_compress: deflate returned %d (%s)\n",
                   r, (state->strm.msg? state->strm.msg: ""));
            break;
        }
        if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
            break;              /* all done */
        if (state->strm.avail_in == 0 && mp != NULL) {
            state->strm.next_in = mtod(mp, u_char *);
            state->strm.avail_in = mp->m_len;
            mp = mp->m_next;
            if (mp == NULL)
                flush = Z_PACKET_FLUSH;
        }
        if (state->strm.avail_out == 0) {
            if (m != NULL) {
                m->m_len = wspace;
                olen += wspace;
                MGET(m->m_next, M_DONTWAIT, MT_DATA);
                m = m->m_next;
                if (m != NULL) {
                    m->m_len = 0;
                    if (maxolen - olen > MLEN)
                        MCLGET(m, M_DONTWAIT);
                    state->strm.next_out = mtod(m, u_char *);
                    state->strm.avail_out = wspace = M_TRAILINGSPACE(m);
                }
            }
            if (m == NULL) {
                state->strm.next_out = NULL;
                state->strm.avail_out = 1000000;
            }
        }
    }
    if (m != NULL)
        olen += (m->m_len = wspace - 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 (m != NULL && olen < orig_len
        && !(olen == PPP_HDRLEN + 3 && *wptr == 0)) {
        state->stats.comp_bytes += olen;
        state->stats.comp_packets++;
    } else {
        if (*mret != NULL) {
            m_freem(*mret);
            *mret = NULL;
        }
        state->stats.inc_bytes += orig_len;
        state->stats.inc_packets++;
        olen = orig_len;
    }
    state->stats.unc_bytes += orig_len;
    state->stats.unc_packets++;
 
    return olen;
}
 
static void
z_comp_stats(arg, stats)
    void *arg;
    struct compstat *stats;
{
    struct deflate_state *state = (struct deflate_state *) arg;
    u_int out;
 
    *stats = state->stats;
    stats->ratio = stats->unc_bytes;
    out = stats->comp_bytes + stats->inc_bytes;
    if (stats->ratio <= 0x7ffffff)
        stats->ratio <<= 8;
    else
        out >>= 8;
    if (out != 0)
        stats->ratio /= out;
}
 
/*
 * Allocate space for a decompressor.
 */
static void *
z_decomp_alloc(options, opt_len)
    u_char *options;
    int opt_len;
{
    struct 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;
 
    MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
           M_DEVBUF, M_NOWAIT);
    if (state == NULL)
        return NULL;
 
    state->strm.next_out = NULL;
    state->strm.zalloc = zalloc;
    state->strm.zfree = zfree;
    if (inflateInit2(&state->strm, -w_size) != Z_OK) {
        FREE(state, M_DEVBUF);
        return NULL;
    }
 
    state->w_size = w_size;
    bzero(&state->stats, sizeof(state->stats));
    return (void *) state;
}
 
static void
z_decomp_free(arg)
    void *arg;
{
    struct deflate_state *state = (struct deflate_state *) arg;
 
    inflateEnd(&state->strm);
    FREE(state, M_DEVBUF);
}
 
static int
z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
    void *arg;
    u_char *options;
    int opt_len, unit, hdrlen, mru, debug;
{
    struct deflate_state *state = (struct 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->hdrlen = hdrlen;
    state->debug = debug;
    state->mru = mru;
 
    inflateReset(&state->strm);
 
    return 1;
}
 
static void
z_decomp_reset(arg)
    void *arg;
{
    struct deflate_state *state = (struct 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, mi, mop)
    void *arg;
    struct mbuf *mi, **mop;
{
    struct deflate_state *state = (struct deflate_state *) arg;
    struct mbuf *mo, *mo_head;
    u_char *rptr, *wptr;
    int rlen, olen, ospace;
    int seq, i, flush, r, decode_proto;
    u_char hdr[PPP_HDRLEN + DEFLATE_OVHD];
 
    *mop = NULL;
    rptr = mtod(mi, u_char *);
    rlen = mi->m_len;
    for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) {
        while (rlen <= 0) {
            mi = mi->m_next;
            if (mi == NULL)
                return DECOMP_ERROR;
            rptr = mtod(mi, u_char *);
            rlen = mi->m_len;
        }
        hdr[i] = *rptr++;
        --rlen;
    }
 
    /* Check the sequence number. */
    seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1];
    if (seq != state->seqno) {
        if (state->debug)
            printf("z_decompress%d: bad seq # %d, expected %d\n",
                   state->unit, seq, state->seqno);
        return DECOMP_ERROR;
    }
    ++state->seqno;
 
    /* Allocate an output mbuf. */
    MGETHDR(mo, M_DONTWAIT, MT_DATA);
    if (mo == NULL)
        return DECOMP_ERROR;
    mo_head = mo;
    mo->m_len = 0;
    mo->m_next = NULL;
    MCLGET(mo, M_DONTWAIT);
    ospace = M_TRAILINGSPACE(mo);
    if (state->hdrlen + PPP_HDRLEN < ospace) {
        mo->m_data += state->hdrlen;
        ospace -= state->hdrlen;
    }
 
    /*
     * Fill in the first part of the PPP header.  The protocol field
     * comes from the decompressed data.
     */
    wptr = mtod(mo, u_char *);
    wptr[0] = PPP_ADDRESS(hdr);
    wptr[1] = PPP_CONTROL(hdr);
    wptr[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 = rptr;
    state->strm.avail_in = rlen;
    mi = mi->m_next;
    flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
    rlen += PPP_HDRLEN + DEFLATE_OVHD;
    state->strm.next_out = wptr + 3;
    state->strm.avail_out = 1;
    decode_proto = 1;
    olen = PPP_HDRLEN;
 
    /*
     * Call inflate, supplying more input or output as needed.
     */
    for (;;) {
        r = inflate(&state->strm, flush);
        if (r != Z_OK) {
#if !DEFLATE_DEBUG
            if (state->debug)
#endif
                printf("z_decompress%d: inflate returned %d (%s)\n",
                       state->unit, r, (state->strm.msg? state->strm.msg: ""));
            m_freem(mo_head);
            return DECOMP_FATALERROR;
        }
        if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
            break;              /* all done */
        if (state->strm.avail_in == 0 && mi != NULL) {
            state->strm.next_in = mtod(mi, u_char *);
            state->strm.avail_in = mi->m_len;
            rlen += mi->m_len;
            mi = mi->m_next;
            if (mi == NULL)
                flush = Z_PACKET_FLUSH;
        }
        if (state->strm.avail_out == 0) {
            if (decode_proto) {
                state->strm.avail_out = ospace - PPP_HDRLEN;
                if ((wptr[3] & 1) == 0) {
                    /* 2-byte protocol field */
                    wptr[2] = wptr[3];
                    --state->strm.next_out;
                    ++state->strm.avail_out;
                    --olen;
                }
                decode_proto = 0;
            } else {
                mo->m_len = ospace;
                olen += ospace;
                MGET(mo->m_next, M_DONTWAIT, MT_DATA);
                mo = mo->m_next;
                if (mo == NULL) {
                    m_freem(mo_head);
                    return DECOMP_ERROR;
                }
                MCLGET(mo, M_DONTWAIT);
                state->strm.next_out = mtod(mo, u_char *);
                state->strm.avail_out = ospace = M_TRAILINGSPACE(mo);
            }
        }
    }
    if (decode_proto) {
        m_freem(mo_head);
        return DECOMP_ERROR;
    }
    olen += (mo->m_len = ospace - state->strm.avail_out);
#if DEFLATE_DEBUG
    if (olen > state->mru + PPP_HDRLEN)
        printf("ppp_deflate%d: exceeded mru (%d > %d)\n",
               state->unit, olen, state->mru + PPP_HDRLEN);
#endif
 
    state->stats.unc_bytes += olen;
    state->stats.unc_packets++;
    state->stats.comp_bytes += rlen;
    state->stats.comp_packets++;
 
    *mop = mo_head;
    return DECOMP_OK;
}
 
/*
 * Incompressible data has arrived - add it to the history.
 */
static void
z_incomp(arg, mi)
    void *arg;
    struct mbuf *mi;
{
    struct deflate_state *state = (struct deflate_state *) arg;
    u_char *rptr;
    int rlen, proto, r;
 
    /*
     * Check that the protocol is one we handle.
     */
    rptr = mtod(mi, u_char *);
    proto = PPP_PROTOCOL(rptr);
    if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
        return;
 
    ++state->seqno;
 
    /*
     * Iterate through the mbufs, adding the characters in them
     * to the decompressor's history.  For the first mbuf, we start
     * at the either the 1st or 2nd byte of the protocol field,
     * depending on whether the protocol value is compressible.
     */
    rlen = mi->m_len;
    state->strm.next_in = rptr + 3;
    state->strm.avail_in = rlen - 3;
    if (proto > 0xff) {
        --state->strm.next_in;
        ++state->strm.avail_in;
    }
    for (;;) {
        r = inflateIncomp(&state->strm);
        if (r != Z_OK) {
            /* gak! */
#if !DEFLATE_DEBUG
            if (state->debug)
#endif
                printf("z_incomp%d: inflateIncomp returned %d (%s)\n",
                       state->unit, r, (state->strm.msg? state->strm.msg: ""));
            return;
        }
        mi = mi->m_next;
        if (mi == NULL)
            break;
        state->strm.next_in = mtod(mi, u_char *);
        state->strm.avail_in = mi->m_len;
        rlen += mi->m_len;
    }
 
    /*
     * Update stats.
     */
    state->stats.inc_bytes += rlen;
    state->stats.inc_packets++;
    state->stats.unc_bytes += rlen;
    state->stats.unc_packets++;
}
 
#endif /* DO_DEFLATE */

Browse

Tools

Subversion Repositories or1k

[/] [or1k/] [trunk/] [rtems-20020807/] [cpukit/] [libnetworking/] [net/] [ppp-deflate.c] - Blame information for rev 1774

Line No.	Rev	Author	Line
1	1026	ivang	`/* ppp-deflate.c,v 1.1 2002/01/31 21:40:47 joel Exp */`
2
3			`/*`
4			`* ppp_deflate.c - interface the zlib procedures for Deflate compression`
5			`* and decompression (as used by gzip) to the PPP code.`
6			`* This version is for use with mbufs on BSD-derived systems.`
7			`*`
8			`* Copyright (c) 1994 The Australian National University.`
9			`* All rights reserved.`
10			`*`
11			`* Permission to use, copy, modify, and distribute this software and its`
12			`* documentation is hereby granted, provided that the above copyright`
13			`* notice appears in all copies. This software is provided without any`
14			`* warranty, express or implied. The Australian National University`
15			`* makes no representations about the suitability of this software for`
16			`* any purpose.`
17			`*`
18			`* IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY`
19			`* PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES`
20			`* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF`
21			`* THE AUSTRALIAN NATIONAL UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY`
22			`* OF SUCH DAMAGE.`
23			`*`
24			`* THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,`
25			`* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY`
26			`* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS`
27			`* ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO`
28			`* OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,`
29			`* OR MODIFICATIONS.`
30			`*/`
31
32			`#include <sys/param.h>`
33			`#include <sys/types.h>`
34			`#include <sys/systm.h>`
35			`#include <sys/mbuf.h>`
36			`#include <net/ppp_defs.h>`
37			`#include <net/zlib.h>`
38
39			`#define PACKETPTR struct mbuf *`
40			`#include <net/ppp-comp.h>`
41
42			`#if DO_DEFLATE`
43
44			`#define DEFLATE_DEBUG 1`
45
46			`/*`
47			`* State for a Deflate (de)compressor.`
48			`*/`
49			`struct deflate_state {`
50			`int seqno;`
51			`int w_size;`
52			`int unit;`
53			`int hdrlen;`
54			`int mru;`
55			`int debug;`
56			`z_stream strm;`
57			`struct compstat stats;`
58			`};`
59
60			`#define DEFLATE_OVHD 2 /* Deflate overhead/packet */`
61
62			`static void zalloc __P((void , u_int items, u_int size));`
63			`static void zfree __P((void , void ptr));`
64			`static void z_comp_alloc __P((u_char options, int opt_len));`
65			`static void z_decomp_alloc __P((u_char options, int opt_len));`
66			`static void z_comp_free __P((void *state));`
67			`static void z_decomp_free __P((void *state));`
68			`static int z_comp_init __P((void state, u_char options, int opt_len,`
69			`int unit, int hdrlen, int debug));`
70			`static int z_decomp_init __P((void state, u_char options, int opt_len,`
71			`int unit, int hdrlen, int mru, int debug));`
72			`static int z_compress __P((void state, struct mbuf *mret,`
73			`struct mbuf *mp, int slen, int maxolen));`
74			`static void z_incomp __P((void state, struct mbuf dmsg));`
75			`static int z_decompress __P((void state, struct mbuf cmp,`
76			`struct mbuf **dmpp));`
77			`static void z_comp_reset __P((void *state));`
78			`static void z_decomp_reset __P((void *state));`
79			`static void z_comp_stats __P((void state, struct compstat stats));`
80
81			`/*`
82			`* Procedures exported to if_ppp.c.`
83			`*/`
84			`struct compressor ppp_deflate = {`
85			`CI_DEFLATE, /* compress_proto */`
86			`z_comp_alloc, /* comp_alloc */`
87			`z_comp_free, /* comp_free */`
88			`z_comp_init, /* comp_init */`
89			`z_comp_reset, /* comp_reset */`
90			`z_compress, /* compress */`
91			`z_comp_stats, /* comp_stat */`
92			`z_decomp_alloc, /* decomp_alloc */`
93			`z_decomp_free, /* decomp_free */`
94			`z_decomp_init, /* decomp_init */`
95			`z_decomp_reset, /* decomp_reset */`
96			`z_decompress, /* decompress */`
97			`z_incomp, /* incomp */`
98			`z_comp_stats, /* decomp_stat */`
99			`};`
100
101			`struct compressor ppp_deflate = {`
102			`CI_DEFLATE_DRAFT, /* compress_proto */`
103			`z_comp_alloc, /* comp_alloc */`
104			`z_comp_free, /* comp_free */`
105			`z_comp_init, /* comp_init */`
106			`z_comp_reset, /* comp_reset */`
107			`z_compress, /* compress */`
108			`z_comp_stats, /* comp_stat */`
109			`z_decomp_alloc, /* decomp_alloc */`
110			`z_decomp_free, /* decomp_free */`
111			`z_decomp_init, /* decomp_init */`
112			`z_decomp_reset, /* decomp_reset */`
113			`z_decompress, /* decompress */`
114			`z_incomp, /* incomp */`
115			`z_comp_stats, /* decomp_stat */`
116			`};`
117
118			`/*`
119			`* Space allocation and freeing routines for use by zlib routines.`
120			`*/`
121			`void *`
122			`zalloc(notused, items, size)`
123			`void *notused;`
124			`u_int items, size;`
125			`{`
126			`void *ptr;`
127
128			`MALLOC(ptr, void , items size, M_DEVBUF, M_NOWAIT);`
129			`return ptr;`
130			`}`
131
132			`void`
133			`zfree(notused, ptr)`
134			`void *notused;`
135			`void *ptr;`
136			`{`
137			`FREE(ptr, M_DEVBUF);`
138			`}`
139
140			`/*`
141			`* Allocate space for a compressor.`
142			`*/`
143			`static void *`
144			`z_comp_alloc(options, opt_len)`
145			`u_char *options;`
146			`int opt_len;`
147			`{`
148			`struct deflate_state *state;`
149			`int w_size;`
150
151			`if (opt_len != CILEN_DEFLATE`
152			`\|\| (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)`
153			`\|\| options[1] != CILEN_DEFLATE`
154			`\|\| DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL`
155			`\|\| options[3] != DEFLATE_CHK_SEQUENCE)`
156			`return NULL;`
157			`w_size = DEFLATE_SIZE(options[2]);`
158			`if (w_size < DEFLATE_MIN_SIZE \|\| w_size > DEFLATE_MAX_SIZE)`
159			`return NULL;`
160
161			`MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),`
162			`M_DEVBUF, M_NOWAIT);`
163			`if (state == NULL)`
164			`return NULL;`
165
166			`state->strm.next_in = NULL;`
167			`state->strm.zalloc = zalloc;`
168			`state->strm.zfree = zfree;`
169			`if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL,`
170			`-w_size, 8, Z_DEFAULT_STRATEGY) != Z_OK) {`
171			`FREE(state, M_DEVBUF);`
172			`return NULL;`
173			`}`
174
175			`state->w_size = w_size;`
176			`bzero(&state->stats, sizeof(state->stats));`
177			`return (void *) state;`
178			`}`
179
180			`static void`
181			`z_comp_free(arg)`
182			`void *arg;`
183			`{`
184			`struct deflate_state state = (struct deflate_state ) arg;`
185
186			`deflateEnd(&state->strm);`
187			`FREE(state, M_DEVBUF);`
188			`}`
189
190			`static int`
191			`z_comp_init(arg, options, opt_len, unit, hdrlen, debug)`
192			`void *arg;`
193			`u_char *options;`
194			`int opt_len, unit, hdrlen, debug;`
195			`{`
196			`struct deflate_state state = (struct deflate_state ) arg;`
197
198			`if (opt_len < CILEN_DEFLATE`
199			`\|\| (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)`
200			`\|\| options[1] != CILEN_DEFLATE`
201			`\|\| DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL`
202			`\|\| DEFLATE_SIZE(options[2]) != state->w_size`
203			`\|\| options[3] != DEFLATE_CHK_SEQUENCE)`
204			`return 0;`
205
206			`state->seqno = 0;`
207			`state->unit = unit;`
208			`state->hdrlen = hdrlen;`
209			`state->debug = debug;`
210
211			`deflateReset(&state->strm);`
212
213			`return 1;`
214			`}`
215
216			`static void`
217			`z_comp_reset(arg)`
218			`void *arg;`
219			`{`
220			`struct deflate_state state = (struct deflate_state ) arg;`
221
222			`state->seqno = 0;`
223			`deflateReset(&state->strm);`
224			`}`
225
226			`int`
227			`z_compress(arg, mret, mp, orig_len, maxolen)`
228			`void *arg;`
229			`struct mbuf *mret; / compressed packet (out) */`
230			`struct mbuf mp; / uncompressed packet (in) */`
231			`int orig_len, maxolen;`
232			`{`
233			`struct deflate_state state = (struct deflate_state ) arg;`
234			`u_char rptr, wptr;`
235			`int proto, olen, wspace, r, flush;`
236			`struct mbuf *m;`
237
238			`/*`
239			`* Check that the protocol is in the range we handle.`
240			`*/`
241			`rptr = mtod(mp, u_char *);`
242			`proto = PPP_PROTOCOL(rptr);`
243			`if (proto > 0x3fff \|\| proto == 0xfd \|\| proto == 0xfb) {`
244			`*mret = NULL;`
245			`return orig_len;`
246			`}`
247
248			`/* Allocate one mbuf initially. */`
249			`if (maxolen > orig_len)`
250			`maxolen = orig_len;`
251			`MGET(m, M_DONTWAIT, MT_DATA);`
252			`*mret = m;`
253			`if (m != NULL) {`
254			`m->m_len = 0;`
255			`if (maxolen + state->hdrlen > MLEN)`
256			`MCLGET(m, M_DONTWAIT);`
257			`wspace = M_TRAILINGSPACE(m);`
258			`if (state->hdrlen + PPP_HDRLEN + 2 < wspace) {`
259			`m->m_data += state->hdrlen;`
260			`wspace -= state->hdrlen;`
261			`}`
262			`wptr = mtod(m, u_char *);`
263
264			`/*`
265			`* Copy over the PPP header and store the 2-byte sequence number.`
266			`*/`
267			`wptr[0] = PPP_ADDRESS(rptr);`
268			`wptr[1] = PPP_CONTROL(rptr);`
269			`wptr[2] = PPP_COMP >> 8;`
270			`wptr[3] = PPP_COMP;`
271			`wptr += PPP_HDRLEN;`
272			`wptr[0] = state->seqno >> 8;`
273			`wptr[1] = state->seqno;`
274			`wptr += 2;`
275			`state->strm.next_out = wptr;`
276			`state->strm.avail_out = wspace - (PPP_HDRLEN + 2);`
277			`} else {`
278			`state->strm.next_out = NULL;`
279			`state->strm.avail_out = 1000000;`
280			`wptr = NULL;`
281			`wspace = 0;`
282			`}`
283			`++state->seqno;`
284
285			`rptr += (proto > 0xff)? 2: 3; /* skip 1st proto byte if 0 */`
286			`state->strm.next_in = rptr;`
287			`state->strm.avail_in = mtod(mp, u_char *) + mp->m_len - rptr;`
288			`mp = mp->m_next;`
289			`flush = (mp == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;`
290			`olen = 0;`
291			`for (;;) {`
292			`r = deflate(&state->strm, flush);`
293			`if (r != Z_OK) {`
294			`printf("z_compress: deflate returned %d (%s)\n",`
295			`r, (state->strm.msg? state->strm.msg: ""));`
296			`break;`
297			`}`
298			`if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)`
299			`break; /* all done */`
300			`if (state->strm.avail_in == 0 && mp != NULL) {`
301			`state->strm.next_in = mtod(mp, u_char *);`
302			`state->strm.avail_in = mp->m_len;`
303			`mp = mp->m_next;`
304			`if (mp == NULL)`
305			`flush = Z_PACKET_FLUSH;`
306			`}`
307			`if (state->strm.avail_out == 0) {`
308			`if (m != NULL) {`
309			`m->m_len = wspace;`
310			`olen += wspace;`
311			`MGET(m->m_next, M_DONTWAIT, MT_DATA);`
312			`m = m->m_next;`
313			`if (m != NULL) {`
314			`m->m_len = 0;`
315			`if (maxolen - olen > MLEN)`
316			`MCLGET(m, M_DONTWAIT);`
317			`state->strm.next_out = mtod(m, u_char *);`
318			`state->strm.avail_out = wspace = M_TRAILINGSPACE(m);`
319			`}`
320			`}`
321			`if (m == NULL) {`
322			`state->strm.next_out = NULL;`
323			`state->strm.avail_out = 1000000;`
324			`}`
325			`}`
326			`}`
327			`if (m != NULL)`
328			`olen += (m->m_len = wspace - state->strm.avail_out);`
329
330			`/*`
331			`* See if we managed to reduce the size of the packet.`
332			`* If the compressor just gave us a single zero byte, it means`
333			`* the packet was incompressible.`
334			`*/`
335			`if (m != NULL && olen < orig_len`
336			`&& !(olen == PPP_HDRLEN + 3 && *wptr == 0)) {`
337			`state->stats.comp_bytes += olen;`
338			`state->stats.comp_packets++;`
339			`} else {`
340			`if (*mret != NULL) {`
341			`m_freem(*mret);`
342			`*mret = NULL;`
343			`}`
344			`state->stats.inc_bytes += orig_len;`
345			`state->stats.inc_packets++;`
346			`olen = orig_len;`
347			`}`
348			`state->stats.unc_bytes += orig_len;`
349			`state->stats.unc_packets++;`
350
351			`return olen;`
352			`}`
353
354			`static void`
355			`z_comp_stats(arg, stats)`
356			`void *arg;`
357			`struct compstat *stats;`
358			`{`
359			`struct deflate_state state = (struct deflate_state ) arg;`
360			`u_int out;`
361
362			`*stats = state->stats;`
363			`stats->ratio = stats->unc_bytes;`
364			`out = stats->comp_bytes + stats->inc_bytes;`
365			`if (stats->ratio <= 0x7ffffff)`
366			`stats->ratio <<= 8;`
367			`else`
368			`out >>= 8;`
369			`if (out != 0)`
370			`stats->ratio /= out;`
371			`}`
372
373			`/*`
374			`* Allocate space for a decompressor.`
375			`*/`
376			`static void *`
377			`z_decomp_alloc(options, opt_len)`
378			`u_char *options;`
379			`int opt_len;`
380			`{`
381			`struct deflate_state *state;`
382			`int w_size;`
383
384			`if (opt_len != CILEN_DEFLATE`
385			`\|\| (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)`
386			`\|\| options[1] != CILEN_DEFLATE`
387			`\|\| DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL`
388			`\|\| options[3] != DEFLATE_CHK_SEQUENCE)`
389			`return NULL;`
390			`w_size = DEFLATE_SIZE(options[2]);`
391			`if (w_size < DEFLATE_MIN_SIZE \|\| w_size > DEFLATE_MAX_SIZE)`
392			`return NULL;`
393
394			`MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),`
395			`M_DEVBUF, M_NOWAIT);`
396			`if (state == NULL)`
397			`return NULL;`
398
399			`state->strm.next_out = NULL;`
400			`state->strm.zalloc = zalloc;`
401			`state->strm.zfree = zfree;`
402			`if (inflateInit2(&state->strm, -w_size) != Z_OK) {`
403			`FREE(state, M_DEVBUF);`
404			`return NULL;`
405			`}`
406
407			`state->w_size = w_size;`
408			`bzero(&state->stats, sizeof(state->stats));`
409			`return (void *) state;`
410			`}`
411
412			`static void`
413			`z_decomp_free(arg)`
414			`void *arg;`
415			`{`
416			`struct deflate_state state = (struct deflate_state ) arg;`
417
418			`inflateEnd(&state->strm);`
419			`FREE(state, M_DEVBUF);`
420			`}`
421
422			`static int`
423			`z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)`
424			`void *arg;`
425			`u_char *options;`
426			`int opt_len, unit, hdrlen, mru, debug;`
427			`{`
428			`struct deflate_state state = (struct deflate_state ) arg;`
429
430			`if (opt_len < CILEN_DEFLATE`
431			`\|\| (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)`
432			`\|\| options[1] != CILEN_DEFLATE`
433			`\|\| DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL`
434			`\|\| DEFLATE_SIZE(options[2]) != state->w_size`
435			`\|\| options[3] != DEFLATE_CHK_SEQUENCE)`
436			`return 0;`
437
438			`state->seqno = 0;`
439			`state->unit = unit;`
440			`state->hdrlen = hdrlen;`
441			`state->debug = debug;`
442			`state->mru = mru;`
443
444			`inflateReset(&state->strm);`
445
446			`return 1;`
447			`}`
448
449			`static void`
450			`z_decomp_reset(arg)`
451			`void *arg;`
452			`{`
453			`struct deflate_state state = (struct deflate_state ) arg;`
454
455			`state->seqno = 0;`
456			`inflateReset(&state->strm);`
457			`}`
458
459			`/*`
460			`* Decompress a Deflate-compressed packet.`
461			`*`
462			`* Because of patent problems, we return DECOMP_ERROR for errors`
463			`* found by inspecting the input data and for system problems, but`
464			`* DECOMP_FATALERROR for any errors which could possibly be said to`
465			`* be being detected "after" decompression. For DECOMP_ERROR,`
466			`* we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be`
467			`* infringing a patent of Motorola's if we do, so we take CCP down`
468			`* instead.`
469			`*`
470			`* Given that the frame has the correct sequence number and a good FCS,`
471			`* errors such as invalid codes in the input most likely indicate a`
472			`* bug, so we return DECOMP_FATALERROR for them in order to turn off`
473			`* compression, even though they are detected by inspecting the input.`
474			`*/`
475			`int`
476			`z_decompress(arg, mi, mop)`
477			`void *arg;`
478			`struct mbuf mi, *mop;`
479			`{`
480			`struct deflate_state state = (struct deflate_state ) arg;`
481			`struct mbuf mo, mo_head;`
482			`u_char rptr, wptr;`
483			`int rlen, olen, ospace;`
484			`int seq, i, flush, r, decode_proto;`
485			`u_char hdr[PPP_HDRLEN + DEFLATE_OVHD];`
486
487			`*mop = NULL;`
488			`rptr = mtod(mi, u_char *);`
489			`rlen = mi->m_len;`
490			`for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) {`
491			`while (rlen <= 0) {`
492			`mi = mi->m_next;`
493			`if (mi == NULL)`
494			`return DECOMP_ERROR;`
495			`rptr = mtod(mi, u_char *);`
496			`rlen = mi->m_len;`
497			`}`
498			`hdr[i] = *rptr++;`
499			`--rlen;`
500			`}`
501
502			`/* Check the sequence number. */`
503			`seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1];`
504			`if (seq != state->seqno) {`
505			`if (state->debug)`
506			`printf("z_decompress%d: bad seq # %d, expected %d\n",`
507			`state->unit, seq, state->seqno);`
508			`return DECOMP_ERROR;`
509			`}`
510			`++state->seqno;`
511
512			`/* Allocate an output mbuf. */`
513			`MGETHDR(mo, M_DONTWAIT, MT_DATA);`
514			`if (mo == NULL)`
515			`return DECOMP_ERROR;`
516			`mo_head = mo;`
517			`mo->m_len = 0;`
518			`mo->m_next = NULL;`
519			`MCLGET(mo, M_DONTWAIT);`
520			`ospace = M_TRAILINGSPACE(mo);`
521			`if (state->hdrlen + PPP_HDRLEN < ospace) {`
522			`mo->m_data += state->hdrlen;`
523			`ospace -= state->hdrlen;`
524			`}`
525
526			`/*`
527			`* Fill in the first part of the PPP header. The protocol field`
528			`* comes from the decompressed data.`
529			`*/`
530			`wptr = mtod(mo, u_char *);`
531			`wptr[0] = PPP_ADDRESS(hdr);`
532			`wptr[1] = PPP_CONTROL(hdr);`
533			`wptr[2] = 0;`
534
535			`/*`
536			`* Set up to call inflate. We set avail_out to 1 initially so we can`
537			`* look at the first byte of the output and decide whether we have`
538			`* a 1-byte or 2-byte protocol field.`
539			`*/`
540			`state->strm.next_in = rptr;`
541			`state->strm.avail_in = rlen;`
542			`mi = mi->m_next;`
543			`flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;`
544			`rlen += PPP_HDRLEN + DEFLATE_OVHD;`
545			`state->strm.next_out = wptr + 3;`
546			`state->strm.avail_out = 1;`
547			`decode_proto = 1;`
548			`olen = PPP_HDRLEN;`
549
550			`/*`
551			`* Call inflate, supplying more input or output as needed.`
552			`*/`
553			`for (;;) {`
554			`r = inflate(&state->strm, flush);`
555			`if (r != Z_OK) {`
556			`#if !DEFLATE_DEBUG`
557			`if (state->debug)`
558			`#endif`
559			`printf("z_decompress%d: inflate returned %d (%s)\n",`
560			`state->unit, r, (state->strm.msg? state->strm.msg: ""));`
561			`m_freem(mo_head);`
562			`return DECOMP_FATALERROR;`
563			`}`
564			`if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)`
565			`break; /* all done */`
566			`if (state->strm.avail_in == 0 && mi != NULL) {`
567			`state->strm.next_in = mtod(mi, u_char *);`
568			`state->strm.avail_in = mi->m_len;`
569			`rlen += mi->m_len;`
570			`mi = mi->m_next;`
571			`if (mi == NULL)`
572			`flush = Z_PACKET_FLUSH;`
573			`}`
574			`if (state->strm.avail_out == 0) {`
575			`if (decode_proto) {`
576			`state->strm.avail_out = ospace - PPP_HDRLEN;`
577			`if ((wptr[3] & 1) == 0) {`
578			`/* 2-byte protocol field */`
579			`wptr[2] = wptr[3];`
580			`--state->strm.next_out;`
581			`++state->strm.avail_out;`
582			`--olen;`
583			`}`
584			`decode_proto = 0;`
585			`} else {`
586			`mo->m_len = ospace;`
587			`olen += ospace;`
588			`MGET(mo->m_next, M_DONTWAIT, MT_DATA);`
589			`mo = mo->m_next;`
590			`if (mo == NULL) {`
591			`m_freem(mo_head);`
592			`return DECOMP_ERROR;`
593			`}`
594			`MCLGET(mo, M_DONTWAIT);`
595			`state->strm.next_out = mtod(mo, u_char *);`
596			`state->strm.avail_out = ospace = M_TRAILINGSPACE(mo);`
597			`}`
598			`}`
599			`}`
600			`if (decode_proto) {`
601			`m_freem(mo_head);`
602			`return DECOMP_ERROR;`
603			`}`
604			`olen += (mo->m_len = ospace - state->strm.avail_out);`
605			`#if DEFLATE_DEBUG`
606			`if (olen > state->mru + PPP_HDRLEN)`
607			`printf("ppp_deflate%d: exceeded mru (%d > %d)\n",`
608			`state->unit, olen, state->mru + PPP_HDRLEN);`
609			`#endif`
610
611			`state->stats.unc_bytes += olen;`
612			`state->stats.unc_packets++;`
613			`state->stats.comp_bytes += rlen;`
614			`state->stats.comp_packets++;`
615
616			`*mop = mo_head;`
617			`return DECOMP_OK;`
618			`}`
619
620			`/*`
621			`* Incompressible data has arrived - add it to the history.`
622			`*/`
623			`static void`
624			`z_incomp(arg, mi)`
625			`void *arg;`
626			`struct mbuf *mi;`
627			`{`
628			`struct deflate_state state = (struct deflate_state ) arg;`
629			`u_char *rptr;`
630			`int rlen, proto, r;`
631
632			`/*`
633			`* Check that the protocol is one we handle.`
634			`*/`
635			`rptr = mtod(mi, u_char *);`
636			`proto = PPP_PROTOCOL(rptr);`
637			`if (proto > 0x3fff \|\| proto == 0xfd \|\| proto == 0xfb)`
638			`return;`
639
640			`++state->seqno;`
641
642			`/*`
643			`* Iterate through the mbufs, adding the characters in them`
644			`* to the decompressor's history. For the first mbuf, we start`
645			`* at the either the 1st or 2nd byte of the protocol field,`
646			`* depending on whether the protocol value is compressible.`
647			`*/`
648			`rlen = mi->m_len;`
649			`state->strm.next_in = rptr + 3;`
650			`state->strm.avail_in = rlen - 3;`
651			`if (proto > 0xff) {`
652			`--state->strm.next_in;`
653			`++state->strm.avail_in;`
654			`}`
655			`for (;;) {`
656			`r = inflateIncomp(&state->strm);`
657			`if (r != Z_OK) {`
658			`/* gak! */`
659			`#if !DEFLATE_DEBUG`
660			`if (state->debug)`
661			`#endif`
662			`printf("z_incomp%d: inflateIncomp returned %d (%s)\n",`
663			`state->unit, r, (state->strm.msg? state->strm.msg: ""));`
664			`return;`
665			`}`
666			`mi = mi->m_next;`
667			`if (mi == NULL)`
668			`break;`
669			`state->strm.next_in = mtod(mi, u_char *);`
670			`state->strm.avail_in = mi->m_len;`
671			`rlen += mi->m_len;`
672			`}`
673
674			`/*`
675			`* Update stats.`
676			`*/`
677			`state->stats.inc_bytes += rlen;`
678			`state->stats.inc_packets++;`
679			`state->stats.unc_bytes += rlen;`
680			`state->stats.unc_packets++;`
681			`}`
682
683			`#endif /* DO_DEFLATE */`