+/* $Id: ppp-deflate.c,v 1.1 1996/07/01 01:24:27 paulus 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 "../h/param.h"
+#include "../h/types.h"
+#include "../h/mbuf.h"
+#include "../h/socket.h"
+#include "../net/net/if.h"
+#include "ppp_defs.h"
+#include "zlib.h"
+
+#define PACKETPTR struct mbuf *
+#include "ppp-comp.h"
+
+#if DO_DEFLATE
+
+/*
+ * 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, u_int nb));
+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 */
+};
+
+/*
+ * Space allocation and freeing routines for use by zlib routines.
+ */
+void *
+zalloc(notused, items, size)
+ void *notused;
+ u_int items, size;
+{
+ void *ptr;
+
+ KM_ALLOC(ptr, void *, items * size, KM_DEVBUF, KM_NOARG);
+ return ptr;
+}
+
+void
+zfree(notused, ptr, nbytes)
+ void *notused;
+ void *ptr;
+ u_int nbytes;
+{
+ KM_FREE(ptr, KM_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[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, DEFLATE_OVHD+2) != 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[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[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[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 (state->debug)
+ 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);
+
+ 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 (state->debug) {
+ 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 */
projects / ppp.git / commitdiff