forked from Imagelibrary/rtems
Remove (Abandoned in FreeBSD).
This commit is contained in:
Ralf Corsepius
@@ -1,594 +0,0 @@
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/*-
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* Copyright (c) 1989 The Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)slcompress.c 7.7 (Berkeley) 5/7/91
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*/
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/*
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* Routines to compress and uncompess tcp packets (for transmission
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* over low speed serial lines.
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*
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* Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989:
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* - Initial distribution.
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*
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* $Id$
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*/
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#include <sys/types.h>
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/mbuf.h>
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#include <sys/socket.h>
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#include <sys/socketvar.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netinet/tcp.h>
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#include <net/pppcompress.h>
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#ifndef SL_NO_STATS
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#define INCR(counter) ++comp->counter;
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#else
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#define INCR(counter)
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#endif
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#define BCMP(p1, p2, n) bcmp((char *)(p1), (char *)(p2), (int)(n))
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#define BCOPY(p1, p2, n) bcopy((char *)(p1), (char *)(p2), (int)(n))
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#ifndef _KERNEL
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#define ovbcopy bcopy
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#endif
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void
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vj_compress_init(comp, max_state)
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struct vjcompress *comp;
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int max_state;
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{
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register u_int i;
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register struct cstate *tstate = comp->tstate;
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if ((unsigned) max_state > MAX_STATES - 1)
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max_state = MAX_STATES - 1;
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bzero((char *)comp, sizeof(*comp));
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for (i = max_state; i > 0; --i) {
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tstate[i].cs_id = i;
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tstate[i].cs_next = &tstate[i - 1];
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}
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tstate[0].cs_next = &tstate[max_state];
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tstate[0].cs_id = 0;
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comp->last_cs = &tstate[0];
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comp->last_recv = 255;
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comp->last_xmit = 255;
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comp->flags = SLF_TOSS;
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}
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/* ENCODE encodes a number that is known to be non-zero. ENCODEZ
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* checks for zero (since zero has to be encoded in the long, 3 byte
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* form).
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*/
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#define ENCODE(n) { \
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if ((u_short)(n) >= 256) { \
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*cp++ = 0; \
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cp[1] = (n); \
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cp[0] = (n) >> 8; \
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cp += 2; \
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} else { \
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*cp++ = (n); \
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} \
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}
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#define ENCODEZ(n) { \
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if ((u_short)(n) >= 256 || (u_short)(n) == 0) { \
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*cp++ = 0; \
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cp[1] = (n); \
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cp[0] = (n) >> 8; \
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cp += 2; \
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} else { \
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*cp++ = (n); \
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} \
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}
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#define DECODEL(f) { \
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if (*cp == 0) {\
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(f) = htonl(ntohl(f) + ((cp[1] << 8) | cp[2])); \
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cp += 3; \
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} else { \
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(f) = htonl(ntohl(f) + (u_long)*cp++); \
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} \
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}
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#define DECODES(f) { \
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if (*cp == 0) {\
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(f) = htons(ntohs(f) + ((cp[1] << 8) | cp[2])); \
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cp += 3; \
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} else { \
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(f) = htons(ntohs(f) + (u_long)*cp++); \
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} \
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}
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#define DECODEU(f) { \
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if (*cp == 0) {\
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(f) = htons((cp[1] << 8) | cp[2]); \
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cp += 3; \
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} else { \
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(f) = htons((u_long)*cp++); \
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} \
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}
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u_int
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vj_compress_tcp(m, ip, comp, compress_cid)
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struct mbuf *m;
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register struct ip *ip;
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struct vjcompress *comp;
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int compress_cid;
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{
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register struct cstate *cs = comp->last_cs->cs_next;
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register u_int hlen = ip->ip_hl;
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register struct tcphdr *oth;
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register struct tcphdr *th;
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register u_int deltaS, deltaA;
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register u_int changes = 0;
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u_char new_seq[16];
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register u_char *cp = new_seq;
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/*
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* Bail if this is an IP fragment or if the TCP packet isn't
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* `compressible' (i.e., ACK isn't set or some other control bit is
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* set). (We assume that the caller has already made sure the
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* packet is IP proto TCP).
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*/
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if ((ip->ip_off & htons(0x3fff)) || m->m_len < 40)
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return (TYPE_IP);
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th = (struct tcphdr *)&((int *)ip)[hlen];
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if ((th->th_flags & (TH_SYN|TH_FIN|TH_RST|TH_ACK)) != TH_ACK)
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return (TYPE_IP);
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/*
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* Packet is compressible -- we're going to send either a
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* COMPRESSED_TCP or UNCOMPRESSED_TCP packet. Either way we need
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* to locate (or create) the connection state. Special case the
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* most recently used connection since it's most likely to be used
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* again & we don't have to do any reordering if it's used.
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*/
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INCR(sls_packets)
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if (ip->ip_src.s_addr != cs->cs_ip.ip_src.s_addr ||
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ip->ip_dst.s_addr != cs->cs_ip.ip_dst.s_addr ||
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*(int *)th != ((int *)&cs->cs_ip)[cs->cs_ip.ip_hl]) {
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/*
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* Wasn't the first -- search for it.
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*
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* States are kept in a circularly linked list with
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* last_cs pointing to the end of the list. The
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* list is kept in lru order by moving a state to the
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* head of the list whenever it is referenced. Since
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* the list is short and, empirically, the connection
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* we want is almost always near the front, we locate
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* states via linear search. If we don't find a state
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* for the datagram, the oldest state is (re-)used.
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*/
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register struct cstate *lcs;
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register struct cstate *lastcs = comp->last_cs;
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do {
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lcs = cs; cs = cs->cs_next;
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INCR(sls_searches)
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if (ip->ip_src.s_addr == cs->cs_ip.ip_src.s_addr
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&& ip->ip_dst.s_addr == cs->cs_ip.ip_dst.s_addr
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&& *(int *)th == ((int *)&cs->cs_ip)[cs->cs_ip.ip_hl])
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goto found;
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} while (cs != lastcs);
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/*
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* Didn't find it -- re-use oldest cstate. Send an
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* uncompressed packet that tells the other side what
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* connection number we're using for this conversation.
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* Note that since the state list is circular, the oldest
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* state points to the newest and we only need to set
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* last_cs to update the lru linkage.
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*/
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INCR(sls_misses)
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comp->last_cs = lcs;
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hlen += th->th_off;
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hlen <<= 2;
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goto uncompressed;
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found:
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/*
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* Found it -- move to the front on the connection list.
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*/
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if (cs == lastcs)
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comp->last_cs = lcs;
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else {
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lcs->cs_next = cs->cs_next;
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cs->cs_next = lastcs->cs_next;
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lastcs->cs_next = cs;
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||||||
}
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}
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||||||
|
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||||||
/*
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||||||
* Make sure that only what we expect to change changed. The first
|
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* line of the `if' checks the IP protocol version, header length &
|
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||||||
* type of service. The 2nd line checks the "Don't fragment" bit.
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* The 3rd line checks the time-to-live and protocol (the protocol
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* check is unnecessary but costless). The 4th line checks the TCP
|
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||||||
* header length. The 5th line checks IP options, if any. The 6th
|
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||||||
* line checks TCP options, if any. If any of these things are
|
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* different between the previous & current datagram, we send the
|
|
||||||
* current datagram `uncompressed'.
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||||||
*/
|
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||||||
oth = (struct tcphdr *)&((int *)&cs->cs_ip)[hlen];
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||||||
deltaS = hlen;
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hlen += th->th_off;
|
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hlen <<= 2;
|
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||||||
|
|
||||||
if (((u_short *)ip)[0] != ((u_short *)&cs->cs_ip)[0] ||
|
|
||||||
((u_short *)ip)[3] != ((u_short *)&cs->cs_ip)[3] ||
|
|
||||||
((u_short *)ip)[4] != ((u_short *)&cs->cs_ip)[4] ||
|
|
||||||
th->th_off != oth->th_off ||
|
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||||||
(deltaS > 5 &&
|
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||||||
BCMP(ip + 1, &cs->cs_ip + 1, (deltaS - 5) << 2)) ||
|
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||||||
(th->th_off > 5 &&
|
|
||||||
BCMP(th + 1, oth + 1, (th->th_off - 5) << 2)))
|
|
||||||
goto uncompressed;
|
|
||||||
|
|
||||||
/*
|
|
||||||
* Figure out which of the changing fields changed. The
|
|
||||||
* receiver expects changes in the order: urgent, window,
|
|
||||||
* ack, seq (the order minimizes the number of temporaries
|
|
||||||
* needed in this section of code).
|
|
||||||
*/
|
|
||||||
if (th->th_flags & TH_URG) {
|
|
||||||
deltaS = ntohs(th->th_urp);
|
|
||||||
ENCODEZ(deltaS);
|
|
||||||
changes |= NEW_U;
|
|
||||||
} else if (th->th_urp != oth->th_urp)
|
|
||||||
/* argh! URG not set but urp changed -- a sensible
|
|
||||||
* implementation should never do this but RFC793
|
|
||||||
* doesn't prohibit the change so we have to deal
|
|
||||||
* with it. */
|
|
||||||
goto uncompressed;
|
|
||||||
|
|
||||||
if ((deltaS = (u_short)(ntohs(th->th_win) - ntohs(oth->th_win)))) {
|
|
||||||
ENCODE(deltaS);
|
|
||||||
changes |= NEW_W;
|
|
||||||
}
|
|
||||||
|
|
||||||
if ((deltaA = ntohl(th->th_ack) - ntohl(oth->th_ack))) {
|
|
||||||
if (deltaA > 0xffff)
|
|
||||||
goto uncompressed;
|
|
||||||
ENCODE(deltaA);
|
|
||||||
changes |= NEW_A;
|
|
||||||
}
|
|
||||||
|
|
||||||
if ((deltaS = ntohl(th->th_seq) - ntohl(oth->th_seq))) {
|
|
||||||
if (deltaS > 0xffff)
|
|
||||||
goto uncompressed;
|
|
||||||
ENCODE(deltaS);
|
|
||||||
changes |= NEW_S;
|
|
||||||
}
|
|
||||||
|
|
||||||
switch(changes) {
|
|
||||||
|
|
||||||
case 0:
|
|
||||||
/*
|
|
||||||
* Nothing changed. If this packet contains data and the
|
|
||||||
* last one didn't, this is probably a data packet following
|
|
||||||
* an ack (normal on an interactive connection) and we send
|
|
||||||
* it compressed. Otherwise it's probably a retransmit,
|
|
||||||
* retransmitted ack or window probe. Send it uncompressed
|
|
||||||
* in case the other side missed the compressed version.
|
|
||||||
*/
|
|
||||||
if (ip->ip_len != cs->cs_ip.ip_len &&
|
|
||||||
ntohs(cs->cs_ip.ip_len) == hlen)
|
|
||||||
break;
|
|
||||||
|
|
||||||
/* (fall through) */
|
|
||||||
|
|
||||||
case SPECIAL_I:
|
|
||||||
case SPECIAL_D:
|
|
||||||
/*
|
|
||||||
* actual changes match one of our special case encodings --
|
|
||||||
* send packet uncompressed.
|
|
||||||
*/
|
|
||||||
goto uncompressed;
|
|
||||||
|
|
||||||
case NEW_S|NEW_A:
|
|
||||||
if (deltaS == deltaA &&
|
|
||||||
deltaS == ntohs(cs->cs_ip.ip_len) - hlen) {
|
|
||||||
/* special case for echoed terminal traffic */
|
|
||||||
changes = SPECIAL_I;
|
|
||||||
cp = new_seq;
|
|
||||||
}
|
|
||||||
break;
|
|
||||||
|
|
||||||
case NEW_S:
|
|
||||||
if (deltaS == ntohs(cs->cs_ip.ip_len) - hlen) {
|
|
||||||
/* special case for data xfer */
|
|
||||||
changes = SPECIAL_D;
|
|
||||||
cp = new_seq;
|
|
||||||
}
|
|
||||||
break;
|
|
||||||
}
|
|
||||||
|
|
||||||
deltaS = ntohs(ip->ip_id) - ntohs(cs->cs_ip.ip_id);
|
|
||||||
if (deltaS != 1) {
|
|
||||||
ENCODEZ(deltaS);
|
|
||||||
changes |= NEW_I;
|
|
||||||
}
|
|
||||||
if (th->th_flags & TH_PUSH)
|
|
||||||
changes |= TCP_PUSH_BIT;
|
|
||||||
/*
|
|
||||||
* Grab the cksum before we overwrite it below. Then update our
|
|
||||||
* state with this packet's header.
|
|
||||||
*/
|
|
||||||
deltaA = ntohs(th->th_sum);
|
|
||||||
BCOPY(ip, &cs->cs_ip, hlen);
|
|
||||||
|
|
||||||
/*
|
|
||||||
* We want to use the original packet as our compressed packet.
|
|
||||||
* (cp - new_seq) is the number of bytes we need for compressed
|
|
||||||
* sequence numbers. In addition we need one byte for the change
|
|
||||||
* mask, one for the connection id and two for the tcp checksum.
|
|
||||||
* So, (cp - new_seq) + 4 bytes of header are needed. hlen is how
|
|
||||||
* many bytes of the original packet to toss so subtract the two to
|
|
||||||
* get the new packet size.
|
|
||||||
*/
|
|
||||||
deltaS = cp - new_seq;
|
|
||||||
cp = (u_char *)ip;
|
|
||||||
if (compress_cid == 0 || comp->last_xmit != cs->cs_id) {
|
|
||||||
comp->last_xmit = cs->cs_id;
|
|
||||||
hlen -= deltaS + 4;
|
|
||||||
cp += hlen;
|
|
||||||
*cp++ = changes | NEW_C;
|
|
||||||
*cp++ = cs->cs_id;
|
|
||||||
} else {
|
|
||||||
hlen -= deltaS + 3;
|
|
||||||
cp += hlen;
|
|
||||||
*cp++ = changes;
|
|
||||||
}
|
|
||||||
m->m_len -= hlen;
|
|
||||||
m->m_data += hlen;
|
|
||||||
*cp++ = deltaA >> 8;
|
|
||||||
*cp++ = deltaA;
|
|
||||||
BCOPY(new_seq, cp, deltaS);
|
|
||||||
INCR(sls_compressed)
|
|
||||||
return (TYPE_COMPRESSED_TCP);
|
|
||||||
|
|
||||||
/*
|
|
||||||
* Update connection state cs & send uncompressed packet ('uncompressed'
|
|
||||||
* means a regular ip/tcp packet but with the 'conversation id' we hope
|
|
||||||
* to use on future compressed packets in the protocol field).
|
|
||||||
*/
|
|
||||||
uncompressed:
|
|
||||||
BCOPY(ip, &cs->cs_ip, hlen);
|
|
||||||
ip->ip_p = cs->cs_id;
|
|
||||||
comp->last_xmit = cs->cs_id;
|
|
||||||
return (TYPE_UNCOMPRESSED_TCP);
|
|
||||||
}
|
|
||||||
|
|
||||||
|
|
||||||
int
|
|
||||||
vj_uncompress_tcp(bufp, len, type, comp)
|
|
||||||
u_char **bufp;
|
|
||||||
int len;
|
|
||||||
u_int type;
|
|
||||||
struct vjcompress *comp;
|
|
||||||
{
|
|
||||||
u_char *hdr, *cp;
|
|
||||||
u_int hlen;
|
|
||||||
int vjlen;
|
|
||||||
|
|
||||||
cp = bufp? *bufp: NULL;
|
|
||||||
vjlen = vj_uncompress_tcp_core(cp, len, len, type, comp, &hdr, &hlen);
|
|
||||||
if (vjlen < 0)
|
|
||||||
return (0); /* error */
|
|
||||||
if (vjlen == 0)
|
|
||||||
return (len); /* was uncompressed already */
|
|
||||||
|
|
||||||
cp += vjlen;
|
|
||||||
len -= vjlen;
|
|
||||||
|
|
||||||
/*
|
|
||||||
* At this point, cp points to the first byte of data in the
|
|
||||||
* packet. If we're not aligned on a 4-byte boundary, copy the
|
|
||||||
* data down so the ip & tcp headers will be aligned. Then back up
|
|
||||||
* cp by the tcp/ip header length to make room for the reconstructed
|
|
||||||
* header (we assume the packet we were handed has enough space to
|
|
||||||
* prepend 128 bytes of header).
|
|
||||||
*/
|
|
||||||
if ((intptr_t)cp & 3) {
|
|
||||||
if (len > 0)
|
|
||||||
(void) ovbcopy(cp, (caddr_t)((intptr_t)cp &~ 3), len);
|
|
||||||
cp = (u_char *)((intptr_t)cp &~ 3);
|
|
||||||
}
|
|
||||||
cp -= hlen;
|
|
||||||
len += hlen;
|
|
||||||
BCOPY(hdr, cp, hlen);
|
|
||||||
|
|
||||||
*bufp = cp;
|
|
||||||
return (len);
|
|
||||||
}
|
|
||||||
|
|
||||||
/*
|
|
||||||
* Uncompress a packet of total length total_len. The first buflen
|
|
||||||
* bytes are at buf; this must include the entire (compressed or
|
|
||||||
* uncompressed) TCP/IP header. This procedure returns the length
|
|
||||||
* of the VJ header, with a pointer to the uncompressed IP header
|
|
||||||
* in *hdrp and its length in *hlenp.
|
|
||||||
*/
|
|
||||||
int
|
|
||||||
vj_uncompress_tcp_core(buf, buflen, total_len, type, comp, hdrp, hlenp)
|
|
||||||
u_char *buf;
|
|
||||||
int buflen, total_len;
|
|
||||||
u_int type;
|
|
||||||
struct vjcompress *comp;
|
|
||||||
u_char **hdrp;
|
|
||||||
u_int *hlenp;
|
|
||||||
{
|
|
||||||
register u_char *cp;
|
|
||||||
register uint32_t hlen, changes;
|
|
||||||
register struct tcphdr *th;
|
|
||||||
register struct cstate *cs;
|
|
||||||
register struct ip *ip;
|
|
||||||
register u_short *bp;
|
|
||||||
register u_int vjlen;
|
|
||||||
|
|
||||||
switch (type) {
|
|
||||||
|
|
||||||
case TYPE_UNCOMPRESSED_TCP:
|
|
||||||
ip = (struct ip *) buf;
|
|
||||||
if (ip->ip_p >= MAX_STATES)
|
|
||||||
goto bad;
|
|
||||||
cs = &comp->rstate[comp->last_recv = ip->ip_p];
|
|
||||||
comp->flags &=~ SLF_TOSS;
|
|
||||||
ip->ip_p = IPPROTO_TCP;
|
|
||||||
/*
|
|
||||||
* Calculate the size of the TCP/IP header and make sure that
|
|
||||||
* we don't overflow the space we have available for it.
|
|
||||||
*/
|
|
||||||
hlen = ip->ip_hl << 2;
|
|
||||||
if (hlen + sizeof(struct tcphdr) > buflen)
|
|
||||||
goto bad;
|
|
||||||
hlen += ((struct tcphdr *)&((char *)ip)[hlen])->th_off << 2;
|
|
||||||
if (hlen > MAX_HDR || hlen > buflen)
|
|
||||||
goto bad;
|
|
||||||
BCOPY(ip, &cs->cs_ip, hlen);
|
|
||||||
cs->cs_hlen = hlen;
|
|
||||||
INCR(sls_uncompressedin)
|
|
||||||
*hdrp = (u_char *) &cs->cs_ip;
|
|
||||||
*hlenp = hlen;
|
|
||||||
return (0);
|
|
||||||
|
|
||||||
default:
|
|
||||||
goto bad;
|
|
||||||
|
|
||||||
case TYPE_COMPRESSED_TCP:
|
|
||||||
break;
|
|
||||||
}
|
|
||||||
/* We've got a compressed packet. */
|
|
||||||
INCR(sls_compressedin)
|
|
||||||
cp = buf;
|
|
||||||
changes = *cp++;
|
|
||||||
if (changes & NEW_C) {
|
|
||||||
/* Make sure the state index is in range, then grab the state.
|
|
||||||
* If we have a good state index, clear the 'discard' flag. */
|
|
||||||
if (*cp >= MAX_STATES)
|
|
||||||
goto bad;
|
|
||||||
|
|
||||||
comp->flags &=~ SLF_TOSS;
|
|
||||||
comp->last_recv = *cp++;
|
|
||||||
} else {
|
|
||||||
/* this packet has an implicit state index. If we've
|
|
||||||
* had a line error since the last time we got an
|
|
||||||
* explicit state index, we have to toss the packet. */
|
|
||||||
if (comp->flags & SLF_TOSS) {
|
|
||||||
INCR(sls_tossed)
|
|
||||||
return (-1);
|
|
||||||
}
|
|
||||||
}
|
|
||||||
cs = &comp->rstate[comp->last_recv];
|
|
||||||
hlen = cs->cs_ip.ip_hl << 2;
|
|
||||||
th = (struct tcphdr *)&((u_char *)&cs->cs_ip)[hlen];
|
|
||||||
th->th_sum = htons((*cp << 8) | cp[1]);
|
|
||||||
cp += 2;
|
|
||||||
if (changes & TCP_PUSH_BIT)
|
|
||||||
th->th_flags |= TH_PUSH;
|
|
||||||
else
|
|
||||||
th->th_flags &=~ TH_PUSH;
|
|
||||||
|
|
||||||
switch (changes & SPECIALS_MASK) {
|
|
||||||
case SPECIAL_I:
|
|
||||||
{
|
|
||||||
register u_int i = ntohs(cs->cs_ip.ip_len) - cs->cs_hlen;
|
|
||||||
th->th_ack = htonl(ntohl(th->th_ack) + i);
|
|
||||||
th->th_seq = htonl(ntohl(th->th_seq) + i);
|
|
||||||
}
|
|
||||||
break;
|
|
||||||
|
|
||||||
case SPECIAL_D:
|
|
||||||
th->th_seq = htonl(ntohl(th->th_seq) + ntohs(cs->cs_ip.ip_len)
|
|
||||||
- cs->cs_hlen);
|
|
||||||
break;
|
|
||||||
|
|
||||||
default:
|
|
||||||
if (changes & NEW_U) {
|
|
||||||
th->th_flags |= TH_URG;
|
|
||||||
DECODEU(th->th_urp)
|
|
||||||
} else
|
|
||||||
th->th_flags &=~ TH_URG;
|
|
||||||
if (changes & NEW_W)
|
|
||||||
DECODES(th->th_win)
|
|
||||||
if (changes & NEW_A)
|
|
||||||
DECODEL(th->th_ack)
|
|
||||||
if (changes & NEW_S)
|
|
||||||
DECODEL(th->th_seq)
|
|
||||||
break;
|
|
||||||
}
|
|
||||||
if (changes & NEW_I) {
|
|
||||||
DECODES(cs->cs_ip.ip_id)
|
|
||||||
} else
|
|
||||||
cs->cs_ip.ip_id = htons(ntohs(cs->cs_ip.ip_id) + 1);
|
|
||||||
|
|
||||||
/*
|
|
||||||
* At this point, cp points to the first byte of data in the
|
|
||||||
* packet. Fill in the IP total length and update the IP
|
|
||||||
* header checksum.
|
|
||||||
*/
|
|
||||||
vjlen = cp - buf;
|
|
||||||
buflen -= vjlen;
|
|
||||||
if (buflen < 0)
|
|
||||||
/* we must have dropped some characters (crc should detect
|
|
||||||
* this but the old slip framing won't) */
|
|
||||||
goto bad;
|
|
||||||
|
|
||||||
total_len += cs->cs_hlen - vjlen;
|
|
||||||
cs->cs_ip.ip_len = htons(total_len);
|
|
||||||
|
|
||||||
/* recompute the ip header checksum */
|
|
||||||
bp = (u_short *) &cs->cs_ip;
|
|
||||||
cs->cs_ip.ip_sum = 0;
|
|
||||||
for (changes = 0; hlen > 0; hlen -= 2)
|
|
||||||
changes += *bp++;
|
|
||||||
changes = (changes & 0xffff) + (changes >> 16);
|
|
||||||
changes = (changes & 0xffff) + (changes >> 16);
|
|
||||||
cs->cs_ip.ip_sum = ~ changes;
|
|
||||||
|
|
||||||
*hdrp = (u_char *) &cs->cs_ip;
|
|
||||||
*hlenp = cs->cs_hlen;
|
|
||||||
return vjlen;
|
|
||||||
|
|
||||||
bad:
|
|
||||||
comp->flags |= SLF_TOSS;
|
|
||||||
INCR(sls_errorin)
|
|
||||||
return (-1);
|
|
||||||
}
|
|
||||||
@@ -1,164 +0,0 @@
|
|||||||
/*
|
|
||||||
* Definitions for tcp compression routines.
|
|
||||||
*
|
|
||||||
* Copyright (c) 1989 Regents of the University of California.
|
|
||||||
* All rights reserved.
|
|
||||||
*
|
|
||||||
* Redistribution and use in source and binary forms, with or without
|
|
||||||
* modification, are permitted provided that the following conditions
|
|
||||||
* are met:
|
|
||||||
* 1. Redistributions of source code must retain the above copyright
|
|
||||||
* notice, this list of conditions and the following disclaimer.
|
|
||||||
* 2. Redistributions in binary form must reproduce the above copyright
|
|
||||||
* notice, this list of conditions and the following disclaimer in the
|
|
||||||
* documentation and/or other materials provided with the distribution.
|
|
||||||
* 3. All advertising materials mentioning features or use of this software
|
|
||||||
* must display the following acknowledgement:
|
|
||||||
* This product includes software developed by the University of
|
|
||||||
* California, Berkeley and its contributors.
|
|
||||||
* 4. Neither the name of the University nor the names of its contributors
|
|
||||||
* may be used to endorse or promote products derived from this software
|
|
||||||
* without specific prior written permission.
|
|
||||||
*
|
|
||||||
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
||||||
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
||||||
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
||||||
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
||||||
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
||||||
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
||||||
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
||||||
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
||||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
||||||
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
||||||
* SUCH DAMAGE.
|
|
||||||
*
|
|
||||||
* Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989:
|
|
||||||
* - Initial distribution.
|
|
||||||
*
|
|
||||||
* From: slcompress.h 7.4 90/06/28
|
|
||||||
* $Id$
|
|
||||||
*/
|
|
||||||
|
|
||||||
#ifndef _NET_PPPCOMPRESS_H_
|
|
||||||
#define _NET_PPPCOMPRESS_H_
|
|
||||||
|
|
||||||
#define MAX_STATES 16 /* must be > 2 and < 256 */
|
|
||||||
#define MAX_HDR MLEN /* XXX 4bsd-ism: should really be 128 */
|
|
||||||
|
|
||||||
/*
|
|
||||||
* Compressed packet format:
|
|
||||||
*
|
|
||||||
* The first octet contains the packet type (top 3 bits), TCP
|
|
||||||
* 'push' bit, and flags that indicate which of the 4 TCP sequence
|
|
||||||
* numbers have changed (bottom 5 bits). The next octet is a
|
|
||||||
* conversation number that associates a saved IP/TCP header with
|
|
||||||
* the compressed packet. The next two octets are the TCP checksum
|
|
||||||
* from the original datagram. The next 0 to 15 octets are
|
|
||||||
* sequence number changes, one change per bit set in the header
|
|
||||||
* (there may be no changes and there are two special cases where
|
|
||||||
* the receiver implicitly knows what changed -- see below).
|
|
||||||
*
|
|
||||||
* There are 5 numbers which can change (they are always inserted
|
|
||||||
* in the following order): TCP urgent pointer, window,
|
|
||||||
* acknowlegement, sequence number and IP ID. (The urgent pointer
|
|
||||||
* is different from the others in that its value is sent, not the
|
|
||||||
* change in value.) Since typical use of SLIP links is biased
|
|
||||||
* toward small packets (see comments on MTU/MSS below), changes
|
|
||||||
* use a variable length coding with one octet for numbers in the
|
|
||||||
* range 1 - 255 and 3 octets (0, MSB, LSB) for numbers in the
|
|
||||||
* range 256 - 65535 or 0. (If the change in sequence number or
|
|
||||||
* ack is more than 65535, an uncompressed packet is sent.)
|
|
||||||
*/
|
|
||||||
|
|
||||||
/*
|
|
||||||
* Packet types (must not conflict with IP protocol version)
|
|
||||||
*
|
|
||||||
* The top nibble of the first octet is the packet type. There are
|
|
||||||
* three possible types: IP (not proto TCP or tcp with one of the
|
|
||||||
* control flags set); uncompressed TCP (a normal IP/TCP packet but
|
|
||||||
* with the 8-bit protocol field replaced by an 8-bit connection id --
|
|
||||||
* this type of packet syncs the sender & receiver); and compressed
|
|
||||||
* TCP (described above).
|
|
||||||
*
|
|
||||||
* LSB of 4-bit field is TCP "PUSH" bit (a worthless anachronism) and
|
|
||||||
* is logically part of the 4-bit "changes" field that follows. Top
|
|
||||||
* three bits are actual packet type. For backward compatibility
|
|
||||||
* and in the interest of conserving bits, numbers are chosen so the
|
|
||||||
* IP protocol version number (4) which normally appears in this nibble
|
|
||||||
* means "IP packet".
|
|
||||||
*/
|
|
||||||
|
|
||||||
/* packet types */
|
|
||||||
#define TYPE_IP 0x40
|
|
||||||
#define TYPE_UNCOMPRESSED_TCP 0x70
|
|
||||||
#define TYPE_COMPRESSED_TCP 0x80
|
|
||||||
#define TYPE_ERROR 0x00
|
|
||||||
|
|
||||||
/* Bits in first octet of compressed packet */
|
|
||||||
#define NEW_C 0x40 /* flag bits for what changed in a packet */
|
|
||||||
#define NEW_I 0x20
|
|
||||||
#define NEW_S 0x08
|
|
||||||
#define NEW_A 0x04
|
|
||||||
#define NEW_W 0x02
|
|
||||||
#define NEW_U 0x01
|
|
||||||
|
|
||||||
/* reserved, special-case values of above */
|
|
||||||
#define SPECIAL_I (NEW_S|NEW_W|NEW_U) /* echoed interactive traffic */
|
|
||||||
#define SPECIAL_D (NEW_S|NEW_A|NEW_W|NEW_U) /* unidirectional data */
|
|
||||||
#define SPECIALS_MASK (NEW_S|NEW_A|NEW_W|NEW_U)
|
|
||||||
|
|
||||||
#define TCP_PUSH_BIT 0x10
|
|
||||||
|
|
||||||
|
|
||||||
/*
|
|
||||||
* "state" data for each active tcp conversation on the wire. This is
|
|
||||||
* basically a copy of the entire IP/TCP header from the last packet
|
|
||||||
* we saw from the conversation together with a small identifier
|
|
||||||
* the transmit & receive ends of the line use to locate saved header.
|
|
||||||
*/
|
|
||||||
struct cstate {
|
|
||||||
struct cstate *cs_next; /* next most recently used cstate (xmit only) */
|
|
||||||
u_short cs_hlen; /* size of hdr (receive only) */
|
|
||||||
u_char cs_id; /* connection # associated with this state */
|
|
||||||
u_char cs_filler;
|
|
||||||
union {
|
|
||||||
char csu_hdr[MAX_HDR];
|
|
||||||
struct ip csu_ip; /* ip/tcp hdr from most recent packet */
|
|
||||||
} slcs_u;
|
|
||||||
};
|
|
||||||
#define cs_ip slcs_u.csu_ip
|
|
||||||
#define cs_hdr slcs_u.csu_hdr
|
|
||||||
|
|
||||||
/*
|
|
||||||
* all the state data for one serial line (we need one of these
|
|
||||||
* per line).
|
|
||||||
*/
|
|
||||||
struct vjcompress {
|
|
||||||
struct cstate *last_cs; /* most recently used tstate */
|
|
||||||
u_char last_recv; /* last rcvd conn. id */
|
|
||||||
u_char last_xmit; /* last sent conn. id */
|
|
||||||
u_short flags;
|
|
||||||
#ifndef SL_NO_STATS
|
|
||||||
int sls_packets; /* outbound packets */
|
|
||||||
int sls_compressed; /* outbound compressed packets */
|
|
||||||
int sls_searches; /* searches for connection state */
|
|
||||||
int sls_misses; /* times couldn't find conn. state */
|
|
||||||
int sls_uncompressedin; /* inbound uncompressed packets */
|
|
||||||
int sls_compressedin; /* inbound compressed packets */
|
|
||||||
int sls_errorin; /* inbound unknown type packets */
|
|
||||||
int sls_tossed; /* inbound packets tossed because of error */
|
|
||||||
#endif
|
|
||||||
struct cstate tstate[MAX_STATES]; /* xmit connection states */
|
|
||||||
struct cstate rstate[MAX_STATES]; /* receive connection states */
|
|
||||||
};
|
|
||||||
/* flag values */
|
|
||||||
#define SLF_TOSS 1 /* tossing rcvd frames because of input err */
|
|
||||||
|
|
||||||
void vj_compress_init(struct vjcompress *, int);
|
|
||||||
u_int vj_compress_tcp(struct mbuf *,
|
|
||||||
struct ip *, struct vjcompress *, int);
|
|
||||||
int vj_uncompress_tcp(u_char **, int, u_int, struct vjcompress *);
|
|
||||||
int vj_uncompress_tcp_core(u_char *, int, int, u_int,
|
|
||||||
struct vjcompress *, u_char **, u_int *);
|
|
||||||
|
|
||||||
#endif /* _NET_PPPCOMPRESS_H_ */
|
|
||||||
Reference in New Issue
Block a user