^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * Routines to compress and uncompress tcp packets (for transmission
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * over low speed serial lines).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (c) 1989 Regents of the University of California.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Redistribution and use in source and binary forms are permitted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * provided that the above copyright notice and this paragraph are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * duplicated in all such forms and that any documentation,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * advertising materials, and other materials related to such
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * distribution and use acknowledge that the software was developed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * by the University of California, Berkeley. The name of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * University may not be used to endorse or promote products derived
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * from this software without specific prior written permission.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * - Initial distribution.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * modified for KA9Q Internet Software Package by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * Katie Stevens (dkstevens@ucdavis.edu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * University of California, Davis
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * Computing Services
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * - 01-31-90 initial adaptation (from 1.19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * PPP.05 02-15-90 [ks]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) * PPP.08 05-02-90 [ks] use PPP protocol field to signal compression
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * PPP.15 09-90 [ks] improve mbuf handling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) * PPP.16 11-02 [karn] substantially rewritten to use NOS facilities
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * - Feb 1991 Bill_Simpson@um.cc.umich.edu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) * variable number of conversation slots
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) * allow zero or one slots
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) * separate routines
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) * status display
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) * - Jul 1994 Dmitry Gorodchanin
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * Fixes for memory leaks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) * - Oct 1994 Dmitry Gorodchanin
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * Modularization.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) * - Jan 1995 Bjorn Ekwall
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) * Use ip_fast_csum from ip.h
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * - July 1995 Christos A. Polyzols
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) * Spotted bug in tcp option checking
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) * This module is a difficult issue. It's clearly inet code but it's also clearly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) * driver code belonging close to PPP and SLIP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) #include <net/slhc_vj.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) #ifdef CONFIG_INET
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) /* Entire module is for IP only */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) #include <linux/socket.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) #include <linux/sockios.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) #include <linux/termios.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) #include <linux/in.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) #include <linux/fcntl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) #include <linux/inet.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) #include <linux/netdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) #include <net/ip.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) #include <net/protocol.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) #include <net/icmp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) #include <net/tcp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) #include <linux/skbuff.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) #include <net/sock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) #include <linux/timer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) #include <net/checksum.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) #include <asm/unaligned.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) static unsigned char *encode(unsigned char *cp, unsigned short n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) static long decode(unsigned char **cpp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) static unsigned char * put16(unsigned char *cp, unsigned short x);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) static unsigned short pull16(unsigned char **cpp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) /* Allocate compression data structure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) * slots must be in range 0 to 255 (zero meaning no compression)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) * Returns pointer to structure or ERR_PTR() on error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) struct slcompress *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) slhc_init(int rslots, int tslots)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) short i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) struct cstate *ts;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) struct slcompress *comp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) if (rslots < 0 || rslots > 255 || tslots < 0 || tslots > 255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) return ERR_PTR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) comp = kzalloc(sizeof(struct slcompress), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) if (! comp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) goto out_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) if (rslots > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) size_t rsize = rslots * sizeof(struct cstate);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) comp->rstate = kzalloc(rsize, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) if (! comp->rstate)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) goto out_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) comp->rslot_limit = rslots - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) if (tslots > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) size_t tsize = tslots * sizeof(struct cstate);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) comp->tstate = kzalloc(tsize, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) if (! comp->tstate)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) goto out_free2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) comp->tslot_limit = tslots - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) comp->xmit_oldest = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) comp->xmit_current = 255;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) comp->recv_current = 255;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) * don't accept any packets with implicit index until we get
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) * one with an explicit index. Otherwise the uncompress code
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) * will try to use connection 255, which is almost certainly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) * out of range
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) comp->flags |= SLF_TOSS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) if ( tslots > 0 ) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) ts = comp->tstate;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) for(i = comp->tslot_limit; i > 0; --i){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) ts[i].cs_this = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) ts[i].next = &(ts[i - 1]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) ts[0].next = &(ts[comp->tslot_limit]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) ts[0].cs_this = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) return comp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) out_free2:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) kfree(comp->rstate);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) out_free:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) kfree(comp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) out_fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) return ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) /* Free a compression data structure */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) slhc_free(struct slcompress *comp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) if ( IS_ERR_OR_NULL(comp) )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) if ( comp->tstate != NULLSLSTATE )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) kfree( comp->tstate );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) if ( comp->rstate != NULLSLSTATE )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) kfree( comp->rstate );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) kfree( comp );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) /* Put a short in host order into a char array in network order */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) static inline unsigned char *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) put16(unsigned char *cp, unsigned short x)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) *cp++ = x >> 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) *cp++ = x;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) return cp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) /* Encode a number */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) static unsigned char *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) encode(unsigned char *cp, unsigned short n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) if(n >= 256 || n == 0){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) *cp++ = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) cp = put16(cp,n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) *cp++ = n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) return cp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) /* Pull a 16-bit integer in host order from buffer in network byte order */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) static unsigned short
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) pull16(unsigned char **cpp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) short rval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) rval = *(*cpp)++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) rval <<= 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) rval |= *(*cpp)++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) return rval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) /* Decode a number */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) static long
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) decode(unsigned char **cpp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) int x;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) x = *(*cpp)++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) if(x == 0){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) return pull16(cpp) & 0xffff; /* pull16 returns -1 on error */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) return x & 0xff; /* -1 if PULLCHAR returned error */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) * icp and isize are the original packet.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) * ocp is a place to put a copy if necessary.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) * cpp is initially a pointer to icp. If the copy is used,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) * change it to ocp.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) slhc_compress(struct slcompress *comp, unsigned char *icp, int isize,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) unsigned char *ocp, unsigned char **cpp, int compress_cid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) struct cstate *ocs = &(comp->tstate[comp->xmit_oldest]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) struct cstate *lcs = ocs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) struct cstate *cs = lcs->next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) unsigned long deltaS, deltaA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) short changes = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) int nlen, hlen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) unsigned char new_seq[16];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) unsigned char *cp = new_seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) struct iphdr *ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) struct tcphdr *th, *oth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) __sum16 csum;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) * Don't play with runt packets.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) if(isize<sizeof(struct iphdr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) return isize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) ip = (struct iphdr *) icp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) if (ip->version != 4 || ip->ihl < 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) return isize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) /* Bail if this packet isn't TCP, or is an IP fragment */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) if (ip->protocol != IPPROTO_TCP || (ntohs(ip->frag_off) & 0x3fff)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) /* Send as regular IP */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) if(ip->protocol != IPPROTO_TCP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) comp->sls_o_nontcp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) comp->sls_o_tcp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) return isize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) nlen = ip->ihl * 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) if (isize < nlen + sizeof(*th))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) return isize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) th = (struct tcphdr *)(icp + nlen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) if (th->doff < sizeof(struct tcphdr) / 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) return isize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) hlen = nlen + th->doff * 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) /* Bail if the TCP packet isn't `compressible' (i.e., ACK isn't set or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) * some other control bit is set). Also uncompressible if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) * it's a runt.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) if(hlen > isize || th->syn || th->fin || th->rst ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) ! (th->ack)){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) /* TCP connection stuff; send as regular IP */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) comp->sls_o_tcp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) return isize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) * Packet is compressible -- we're going to send either a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) * COMPRESSED_TCP or UNCOMPRESSED_TCP packet. Either way,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) * we need to locate (or create) the connection state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) * States are kept in a circularly linked list with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) * xmit_oldest pointing to the end of the list. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) * list is kept in lru order by moving a state to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) * head of the list whenever it is referenced. Since
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) * the list is short and, empirically, the connection
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) * we want is almost always near the front, we locate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) * states via linear search. If we don't find a state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) * for the datagram, the oldest state is (re-)used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) for ( ; ; ) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) if( ip->saddr == cs->cs_ip.saddr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) && ip->daddr == cs->cs_ip.daddr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) && th->source == cs->cs_tcp.source
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) && th->dest == cs->cs_tcp.dest)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) goto found;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) /* if current equal oldest, at end of list */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) if ( cs == ocs )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) lcs = cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) cs = cs->next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) comp->sls_o_searches++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) * Didn't find it -- re-use oldest cstate. Send an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) * uncompressed packet that tells the other side what
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) * connection number we're using for this conversation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) * Note that since the state list is circular, the oldest
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) * state points to the newest and we only need to set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) * xmit_oldest to update the lru linkage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) comp->sls_o_misses++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) comp->xmit_oldest = lcs->cs_this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) goto uncompressed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) found:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) * Found it -- move to the front on the connection list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) if(lcs == ocs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) /* found at most recently used */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) } else if (cs == ocs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) /* found at least recently used */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) comp->xmit_oldest = lcs->cs_this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) /* more than 2 elements */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) lcs->next = cs->next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) cs->next = ocs->next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) ocs->next = cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) * Make sure that only what we expect to change changed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) * Check the following:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) * IP protocol version, header length & type of service.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) * The "Don't fragment" bit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) * The time-to-live field.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) * The TCP header length.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) * IP options, if any.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) * TCP options, if any.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) * If any of these things are different between the previous &
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) * current datagram, we send the current datagram `uncompressed'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) oth = &cs->cs_tcp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) if(ip->version != cs->cs_ip.version || ip->ihl != cs->cs_ip.ihl
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) || ip->tos != cs->cs_ip.tos
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) || (ip->frag_off & htons(0x4000)) != (cs->cs_ip.frag_off & htons(0x4000))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) || ip->ttl != cs->cs_ip.ttl
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) || th->doff != cs->cs_tcp.doff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) || (ip->ihl > 5 && memcmp(ip+1,cs->cs_ipopt,((ip->ihl)-5)*4) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) || (th->doff > 5 && memcmp(th+1,cs->cs_tcpopt,((th->doff)-5)*4) != 0)){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) goto uncompressed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) * Figure out which of the changing fields changed. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) * receiver expects changes in the order: urgent, window,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) * ack, seq (the order minimizes the number of temporaries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) * needed in this section of code).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) if(th->urg){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) deltaS = ntohs(th->urg_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) cp = encode(cp,deltaS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) changes |= NEW_U;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) } else if(th->urg_ptr != oth->urg_ptr){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) /* argh! URG not set but urp changed -- a sensible
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) * implementation should never do this but RFC793
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) * doesn't prohibit the change so we have to deal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) * with it. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) goto uncompressed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) if((deltaS = ntohs(th->window) - ntohs(oth->window)) != 0){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) cp = encode(cp,deltaS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) changes |= NEW_W;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) if((deltaA = ntohl(th->ack_seq) - ntohl(oth->ack_seq)) != 0L){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) if(deltaA > 0x0000ffff)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) goto uncompressed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) cp = encode(cp,deltaA);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) changes |= NEW_A;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) if((deltaS = ntohl(th->seq) - ntohl(oth->seq)) != 0L){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) if(deltaS > 0x0000ffff)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) goto uncompressed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) cp = encode(cp,deltaS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) changes |= NEW_S;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) switch(changes){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) case 0: /* Nothing changed. If this packet contains data and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) * last one didn't, this is probably a data packet following
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) * an ack (normal on an interactive connection) and we send
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) * it compressed. Otherwise it's probably a retransmit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) * retransmitted ack or window probe. Send it uncompressed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) * in case the other side missed the compressed version.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) if(ip->tot_len != cs->cs_ip.tot_len &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) ntohs(cs->cs_ip.tot_len) == hlen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) goto uncompressed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) case SPECIAL_I:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) case SPECIAL_D:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) /* actual changes match one of our special case encodings --
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) * send packet uncompressed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) goto uncompressed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) case NEW_S|NEW_A:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) if(deltaS == deltaA &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) deltaS == ntohs(cs->cs_ip.tot_len) - hlen){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) /* special case for echoed terminal traffic */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) changes = SPECIAL_I;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) cp = new_seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) case NEW_S:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) if(deltaS == ntohs(cs->cs_ip.tot_len) - hlen){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) /* special case for data xfer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) changes = SPECIAL_D;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) cp = new_seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) deltaS = ntohs(ip->id) - ntohs(cs->cs_ip.id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) if(deltaS != 1){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) cp = encode(cp,deltaS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) changes |= NEW_I;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) if(th->psh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) changes |= TCP_PUSH_BIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) /* Grab the cksum before we overwrite it below. Then update our
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) * state with this packet's header.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) csum = th->check;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) memcpy(&cs->cs_ip,ip,20);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) memcpy(&cs->cs_tcp,th,20);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) /* We want to use the original packet as our compressed packet.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) * (cp - new_seq) is the number of bytes we need for compressed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) * sequence numbers. In addition we need one byte for the change
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) * mask, one for the connection id and two for the tcp checksum.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) * So, (cp - new_seq) + 4 bytes of header are needed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) deltaS = cp - new_seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) if(compress_cid == 0 || comp->xmit_current != cs->cs_this){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) cp = ocp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) *cpp = ocp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) *cp++ = changes | NEW_C;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) *cp++ = cs->cs_this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) comp->xmit_current = cs->cs_this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) cp = ocp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) *cpp = ocp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) *cp++ = changes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) *(__sum16 *)cp = csum;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) cp += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) /* deltaS is now the size of the change section of the compressed header */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) memcpy(cp,new_seq,deltaS); /* Write list of deltas */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) memcpy(cp+deltaS,icp+hlen,isize-hlen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) comp->sls_o_compressed++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) ocp[0] |= SL_TYPE_COMPRESSED_TCP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) return isize - hlen + deltaS + (cp - ocp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) /* Update connection state cs & send uncompressed packet (i.e.,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) * a regular ip/tcp packet but with the 'conversation id' we hope
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) * to use on future compressed packets in the protocol field).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) uncompressed:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) memcpy(&cs->cs_ip,ip,20);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) memcpy(&cs->cs_tcp,th,20);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) if (ip->ihl > 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) memcpy(cs->cs_ipopt, ip+1, ((ip->ihl) - 5) * 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) if (th->doff > 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) memcpy(cs->cs_tcpopt, th+1, ((th->doff) - 5) * 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) comp->xmit_current = cs->cs_this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) comp->sls_o_uncompressed++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) memcpy(ocp, icp, isize);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) *cpp = ocp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) ocp[9] = cs->cs_this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) ocp[0] |= SL_TYPE_UNCOMPRESSED_TCP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) return isize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) slhc_uncompress(struct slcompress *comp, unsigned char *icp, int isize)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) int changes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) long x;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) struct tcphdr *thp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) struct iphdr *ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) struct cstate *cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) int len, hdrlen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) unsigned char *cp = icp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) /* We've got a compressed packet; read the change byte */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) comp->sls_i_compressed++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) if(isize < 3){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) comp->sls_i_error++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) changes = *cp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) if(changes & NEW_C){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) /* Make sure the state index is in range, then grab the state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) * If we have a good state index, clear the 'discard' flag.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) x = *cp++; /* Read conn index */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) if(x < 0 || x > comp->rslot_limit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) goto bad;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) /* Check if the cstate is initialized */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) if (!comp->rstate[x].initialized)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) goto bad;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) comp->flags &=~ SLF_TOSS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) comp->recv_current = x;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) /* this packet has an implicit state index. If we've
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) * had a line error since the last time we got an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) * explicit state index, we have to toss the packet. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) if(comp->flags & SLF_TOSS){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) comp->sls_i_tossed++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) cs = &comp->rstate[comp->recv_current];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) thp = &cs->cs_tcp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) ip = &cs->cs_ip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) thp->check = *(__sum16 *)cp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) cp += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) thp->psh = (changes & TCP_PUSH_BIT) ? 1 : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) * we can use the same number for the length of the saved header and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) * the current one, because the packet wouldn't have been sent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) * as compressed unless the options were the same as the previous one
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) hdrlen = ip->ihl * 4 + thp->doff * 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) switch(changes & SPECIALS_MASK){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) case SPECIAL_I: /* Echoed terminal traffic */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) short i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) i = ntohs(ip->tot_len) - hdrlen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) thp->ack_seq = htonl( ntohl(thp->ack_seq) + i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) thp->seq = htonl( ntohl(thp->seq) + i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) case SPECIAL_D: /* Unidirectional data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) thp->seq = htonl( ntohl(thp->seq) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) ntohs(ip->tot_len) - hdrlen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) if(changes & NEW_U){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) thp->urg = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) if((x = decode(&cp)) == -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) goto bad;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) thp->urg_ptr = htons(x);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) thp->urg = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) if(changes & NEW_W){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) if((x = decode(&cp)) == -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) goto bad;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) thp->window = htons( ntohs(thp->window) + x);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) if(changes & NEW_A){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) if((x = decode(&cp)) == -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) goto bad;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) thp->ack_seq = htonl( ntohl(thp->ack_seq) + x);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) if(changes & NEW_S){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) if((x = decode(&cp)) == -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) goto bad;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) thp->seq = htonl( ntohl(thp->seq) + x);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) if(changes & NEW_I){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) if((x = decode(&cp)) == -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) goto bad;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) ip->id = htons (ntohs (ip->id) + x);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) ip->id = htons (ntohs (ip->id) + 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) * At this point, cp points to the first byte of data in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) * packet. Put the reconstructed TCP and IP headers back on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) * packet. Recalculate IP checksum (but not TCP checksum).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) len = isize - (cp - icp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) if (len < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) goto bad;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) len += hdrlen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) ip->tot_len = htons(len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) ip->check = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) memmove(icp + hdrlen, cp, len - hdrlen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) cp = icp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) memcpy(cp, ip, 20);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) cp += 20;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) if (ip->ihl > 5) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) memcpy(cp, cs->cs_ipopt, (ip->ihl - 5) * 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) cp += (ip->ihl - 5) * 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) put_unaligned(ip_fast_csum(icp, ip->ihl),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) &((struct iphdr *)icp)->check);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) memcpy(cp, thp, 20);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) cp += 20;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) if (thp->doff > 5) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) memcpy(cp, cs->cs_tcpopt, ((thp->doff) - 5) * 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) cp += ((thp->doff) - 5) * 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) return len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) bad:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) comp->sls_i_error++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) return slhc_toss( comp );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) slhc_remember(struct slcompress *comp, unsigned char *icp, int isize)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) struct cstate *cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) unsigned ihl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) unsigned char index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) if(isize < 20) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) /* The packet is shorter than a legal IP header */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) comp->sls_i_runt++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) return slhc_toss( comp );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) /* Peek at the IP header's IHL field to find its length */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) ihl = icp[0] & 0xf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) if(ihl < 20 / 4){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) /* The IP header length field is too small */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) comp->sls_i_runt++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) return slhc_toss( comp );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) index = icp[9];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) icp[9] = IPPROTO_TCP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) if (ip_fast_csum(icp, ihl)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) /* Bad IP header checksum; discard */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) comp->sls_i_badcheck++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) return slhc_toss( comp );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) if(index > comp->rslot_limit) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) comp->sls_i_error++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) return slhc_toss(comp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) /* Update local state */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) cs = &comp->rstate[comp->recv_current = index];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) comp->flags &=~ SLF_TOSS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) memcpy(&cs->cs_ip,icp,20);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) memcpy(&cs->cs_tcp,icp + ihl*4,20);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) if (ihl > 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) memcpy(cs->cs_ipopt, icp + sizeof(struct iphdr), (ihl - 5) * 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) if (cs->cs_tcp.doff > 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) memcpy(cs->cs_tcpopt, icp + ihl*4 + sizeof(struct tcphdr), (cs->cs_tcp.doff - 5) * 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) cs->cs_hsize = ihl*2 + cs->cs_tcp.doff*2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) cs->initialized = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) /* Put headers back on packet
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) * Neither header checksum is recalculated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) comp->sls_i_uncompressed++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) return isize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) slhc_toss(struct slcompress *comp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) if ( comp == NULLSLCOMPR )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) comp->flags |= SLF_TOSS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) #else /* CONFIG_INET */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) slhc_toss(struct slcompress *comp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) printk(KERN_DEBUG "Called IP function on non IP-system: slhc_toss");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) slhc_uncompress(struct slcompress *comp, unsigned char *icp, int isize)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) printk(KERN_DEBUG "Called IP function on non IP-system: slhc_uncompress");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) slhc_compress(struct slcompress *comp, unsigned char *icp, int isize,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) unsigned char *ocp, unsigned char **cpp, int compress_cid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) printk(KERN_DEBUG "Called IP function on non IP-system: slhc_compress");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) slhc_remember(struct slcompress *comp, unsigned char *icp, int isize)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) printk(KERN_DEBUG "Called IP function on non IP-system: slhc_remember");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) slhc_free(struct slcompress *comp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) printk(KERN_DEBUG "Called IP function on non IP-system: slhc_free");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) struct slcompress *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) slhc_init(int rslots, int tslots)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) printk(KERN_DEBUG "Called IP function on non IP-system: slhc_init");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) #endif /* CONFIG_INET */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) /* VJ header compression */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) EXPORT_SYMBOL(slhc_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) EXPORT_SYMBOL(slhc_free);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) EXPORT_SYMBOL(slhc_remember);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) EXPORT_SYMBOL(slhc_compress);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) EXPORT_SYMBOL(slhc_uncompress);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) EXPORT_SYMBOL(slhc_toss);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) MODULE_LICENSE("Dual BSD/GPL");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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