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*/
1 /*
2 * Routines to compress and uncompress tcp packets (for transmission
3 * over low speed serial lines).
4 *
5 * Copyright (c) 1989 Regents of the University of California.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms are permitted
9 * provided that the above copyright notice and this paragraph are
10 * duplicated in all such forms and that any documentation,
11 * advertising materials, and other materials related to such
12 * distribution and use acknowledge that the software was developed
13 * by the University of California, Berkeley. The name of the
14 * University may not be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
19 *
20 * Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989:
21 * - Initial distribution.
22 *
23 *
24 * modified for KA9Q Internet Software Package by
25 * Katie Stevens (dkstevens@ucdavis.edu)
26 * University of California, Davis
27 * Computing Services
28 * - 01-31-90 initial adaptation (from 1.19)
29 * PPP.05 02-15-90 [ks]
30 * PPP.08 05-02-90 [ks] use PPP protocol field to signal compression
31 * PPP.15 09-90 [ks] improve mbuf handling
32 * PPP.16 11-02 [karn] substantially rewritten to use NOS facilities
33 *
34 * - Feb 1991 Bill_Simpson@um.cc.umich.edu
35 * variable number of conversation slots
36 * allow zero or one slots
37 * separate routines
38 * status display
39 * - Jul 1994 Dmitry Gorodchanin
40 * Fixes for memory leaks.
41 * - Oct 1994 Dmitry Gorodchanin
42 * Modularization.
43 * - Jan 1995 Bjorn Ekwall
44 * Use ip_fast_csum from ip.h
45 * - July 1995 Christos A. Polyzols
46 * Spotted bug in tcp option checking
47 *
48 *
49 * This module is a difficult issue. It's clearly inet code but it's also clearly
50 * driver code belonging close to PPP and SLIP
51 */
52
53 #include <linux/config.h>
54 #ifdef CONFIG_INET
55 /* Entire module is for IP only */
56 #include <linux/module.h>
57
58 #include <linux/types.h>
59 #include <linux/sched.h>
60 #include <linux/mm.h>
61 #include <linux/string.h>
62 #include <linux/socket.h>
63 #include <linux/sockios.h>
64 #include <linux/termios.h>
65 #include <linux/in.h>
66 #include <linux/fcntl.h>
67 #include <linux/inet.h>
68 #include <linux/netdevice.h>
69 #include <net/ip.h>
70 #include <net/protocol.h>
71 #include <net/icmp.h>
72 #include <net/tcp.h>
73 #include <linux/skbuff.h>
74 #include <net/sock.h>
75 #include <linux/errno.h>
76 #include <linux/timer.h>
77 #include <asm/system.h>
78 #include <asm/segment.h>
79 #include <linux/mm.h>
80 #include <net/checksum.h>
81 #include "slhc.h"
82
83 #ifdef __alpha__
84 # include <asm/unaligned.h>
85 #endif
86
87 int last_retran;
88
89 static unsigned char *encode(unsigned char *cp, unsigned short n);
90 static long decode(unsigned char **cpp);
91 static unsigned char * put16(unsigned char *cp, unsigned short x);
92 static unsigned short pull16(unsigned char **cpp);
93
94 /* Initialize compression data structure
95 * slots must be in range 0 to 255 (zero meaning no compression)
96 */
97 struct slcompress *
98 slhc_init(int rslots, int tslots)
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*/
99 {
100 register short i;
101 register struct cstate *ts;
102 struct slcompress *comp;
103
104 comp = (struct slcompress *)kmalloc(sizeof(struct slcompress),
105 GFP_KERNEL);
106 if (! comp)
107 return NULL;
108
109 memset(comp, 0, sizeof(struct slcompress));
110
111 if ( rslots > 0 && rslots < 256 ) {
112 comp->rstate =
113 (struct cstate *)kmalloc(rslots * sizeof(struct cstate),
114 GFP_KERNEL);
115 if (! comp->rstate)
116 {
117 kfree((unsigned char *)comp);
118 return NULL;
119 }
120 memset(comp->rstate, 0, rslots * sizeof(struct cstate));
121 comp->rslot_limit = rslots - 1;
122 }
123
124 if ( tslots > 0 && tslots < 256 ) {
125 comp->tstate =
126 (struct cstate *)kmalloc(tslots * sizeof(struct cstate),
127 GFP_KERNEL);
128 if (! comp->tstate)
129 {
130 kfree((unsigned char *)comp->rstate);
131 kfree((unsigned char *)comp);
132 return NULL;
133 }
134 memset(comp->tstate, 0, tslots * sizeof(struct cstate));
135 comp->tslot_limit = tslots - 1;
136 }
137
138 comp->xmit_oldest = 0;
139 comp->xmit_current = 255;
140 comp->recv_current = 255;
141 /*
142 * don't accept any packets with implicit index until we get
143 * one with an explicit index. Otherwise the uncompress code
144 * will try to use connection 255, which is almost certainly
145 * out of range
146 */
147 comp->flags |= SLF_TOSS;
148
149 if ( tslots > 0 ) {
150 ts = comp->tstate;
151 for(i = comp->tslot_limit; i > 0; --i){
152 ts[i].cs_this = i;
153 ts[i].next = &(ts[i - 1]);
154 }
155 ts[0].next = &(ts[comp->tslot_limit]);
156 ts[0].cs_this = 0;
157 }
158 MOD_INC_USE_COUNT;
159 return comp;
160 }
161
162
163 /* Free a compression data structure */
164 void
165 slhc_free(struct slcompress *comp)
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166 {
167 if ( comp == NULLSLCOMPR )
168 return;
169
170 if ( comp->rstate != NULLSLSTATE )
171 kfree( comp->rstate );
172
173 if ( comp->tstate != NULLSLSTATE )
174 kfree( comp->tstate );
175
176 MOD_DEC_USE_COUNT;
177 kfree( comp );
178 }
179
180
181 /* Put a short in host order into a char array in network order */
182 static inline unsigned char *
183 put16(unsigned char *cp, unsigned short x)
/* */
184 {
185 *cp++ = x >> 8;
186 *cp++ = x;
187
188 return cp;
189 }
190
191
192 /* Encode a number */
193 unsigned char *
194 encode(unsigned char *cp, unsigned short n)
/* */
195 {
196 if(n >= 256 || n == 0){
197 *cp++ = 0;
198 cp = put16(cp,n);
199 } else {
200 *cp++ = n;
201 }
202 return cp;
203 }
204
205 /* Pull a 16-bit integer in host order from buffer in network byte order */
206 static unsigned short
207 pull16(unsigned char **cpp)
/* */
208 {
209 short rval;
210
211 rval = *(*cpp)++;
212 rval <<= 8;
213 rval |= *(*cpp)++;
214 return rval;
215 }
216
217 /* Decode a number */
218 long
219 decode(unsigned char **cpp)
/* */
220 {
221 register int x;
222
223 x = *(*cpp)++;
224 if(x == 0){
225 return pull16(cpp) & 0xffff; /* pull16 returns -1 on error */
226 } else {
227 return x & 0xff; /* -1 if PULLCHAR returned error */
228 }
229 }
230
231 /*
232 * icp and isize are the original packet.
233 * ocp is a place to put a copy if necessary.
234 * cpp is initially a pointer to icp. If the copy is used,
235 * change it to ocp.
236 */
237
238 int
239 slhc_compress(struct slcompress *comp, unsigned char *icp, int isize,
/* */
240 unsigned char *ocp, unsigned char **cpp, int compress_cid)
241 {
242 register struct cstate *ocs = &(comp->tstate[comp->xmit_oldest]);
243 register struct cstate *lcs = ocs;
244 register struct cstate *cs = lcs->next;
245 register unsigned long deltaS, deltaA;
246 register short changes = 0;
247 int hlen;
248 unsigned char new_seq[16];
249 register unsigned char *cp = new_seq;
250 struct iphdr *ip;
251 struct tcphdr *th, *oth;
252
253 ip = (struct iphdr *) icp;
254
255 /* Bail if this packet isn't TCP, or is an IP fragment */
256 if(ip->protocol != IPPROTO_TCP || (ntohs(ip->frag_off) & 0x1fff) ||
257 (ip->frag_off & 32)){
258 /* Send as regular IP */
259 if(ip->protocol != IPPROTO_TCP)
260 comp->sls_o_nontcp++;
261 else
262 comp->sls_o_tcp++;
263 return isize;
264 }
265 /* Extract TCP header */
266
267 th = (struct tcphdr *)(((unsigned char *)ip) + ip->ihl*4);
268 hlen = ip->ihl*4 + th->doff*4;
269
270 /* Bail if the TCP packet isn't `compressible' (i.e., ACK isn't set or
271 * some other control bit is set).
272 */
273 if(th->syn || th->fin || th->rst ||
274 ! (th->ack)){
275 /* TCP connection stuff; send as regular IP */
276 comp->sls_o_tcp++;
277 return isize;
278 }
279 /*
280 * Packet is compressible -- we're going to send either a
281 * COMPRESSED_TCP or UNCOMPRESSED_TCP packet. Either way,
282 * we need to locate (or create) the connection state.
283 *
284 * States are kept in a circularly linked list with
285 * xmit_oldest pointing to the end of the list. The
286 * list is kept in lru order by moving a state to the
287 * head of the list whenever it is referenced. Since
288 * the list is short and, empirically, the connection
289 * we want is almost always near the front, we locate
290 * states via linear search. If we don't find a state
291 * for the datagram, the oldest state is (re-)used.
292 */
293 for ( ; ; ) {
294 if( ip->saddr == cs->cs_ip.saddr
295 && ip->daddr == cs->cs_ip.daddr
296 && th->source == cs->cs_tcp.source
297 && th->dest == cs->cs_tcp.dest)
298 goto found;
299
300 /* if current equal oldest, at end of list */
301 if ( cs == ocs )
302 break;
303 lcs = cs;
304 cs = cs->next;
305 comp->sls_o_searches++;
306 };
307 /*
308 * Didn't find it -- re-use oldest cstate. Send an
309 * uncompressed packet that tells the other side what
310 * connection number we're using for this conversation.
311 *
312 * Note that since the state list is circular, the oldest
313 * state points to the newest and we only need to set
314 * xmit_oldest to update the lru linkage.
315 */
316 comp->sls_o_misses++;
317 comp->xmit_oldest = lcs->cs_this;
318 goto uncompressed;
319
320 found:
321 /*
322 * Found it -- move to the front on the connection list.
323 */
324 if(lcs == ocs) {
325 /* found at most recently used */
326 } else if (cs == ocs) {
327 /* found at least recently used */
328 comp->xmit_oldest = lcs->cs_this;
329 } else {
330 /* more than 2 elements */
331 lcs->next = cs->next;
332 cs->next = ocs->next;
333 ocs->next = cs;
334 }
335
336 /*
337 * Make sure that only what we expect to change changed.
338 * Check the following:
339 * IP protocol version, header length & type of service.
340 * The "Don't fragment" bit.
341 * The time-to-live field.
342 * The TCP header length.
343 * IP options, if any.
344 * TCP options, if any.
345 * If any of these things are different between the previous &
346 * current datagram, we send the current datagram `uncompressed'.
347 */
348 oth = &cs->cs_tcp;
349
350 if(last_retran
351 || ip->version != cs->cs_ip.version || ip->ihl != cs->cs_ip.ihl
352 || ip->tos != cs->cs_ip.tos
353 || (ip->frag_off & 64) != (cs->cs_ip.frag_off & 64)
354 || ip->ttl != cs->cs_ip.ttl
355 || th->doff != cs->cs_tcp.doff
356 || (ip->ihl > 5 && memcmp(ip+1,cs->cs_ipopt,((ip->ihl)-5)*4) != 0)
357 || (th->doff > 5 && memcmp(th+1,cs->cs_tcpopt,((th->doff)-5)*4) != 0)){
358 goto uncompressed;
359 }
360
361 /*
362 * Figure out which of the changing fields changed. The
363 * receiver expects changes in the order: urgent, window,
364 * ack, seq (the order minimizes the number of temporaries
365 * needed in this section of code).
366 */
367 if(th->urg){
368 deltaS = ntohs(th->urg_ptr);
369 cp = encode(cp,deltaS);
370 changes |= NEW_U;
371 } else if(th->urg_ptr != oth->urg_ptr){
372 /* argh! URG not set but urp changed -- a sensible
373 * implementation should never do this but RFC793
374 * doesn't prohibit the change so we have to deal
375 * with it. */
376 goto uncompressed;
377 }
378 if((deltaS = ntohs(th->window) - ntohs(oth->window)) != 0){
379 cp = encode(cp,deltaS);
380 changes |= NEW_W;
381 }
382 if((deltaA = ntohl(th->ack_seq) - ntohl(oth->ack_seq)) != 0L){
383 if(deltaA > 0x0000ffff)
384 goto uncompressed;
385 cp = encode(cp,deltaA);
386 changes |= NEW_A;
387 }
388 if((deltaS = ntohl(th->seq) - ntohl(oth->seq)) != 0L){
389 if(deltaS > 0x0000ffff)
390 goto uncompressed;
391 cp = encode(cp,deltaS);
392 changes |= NEW_S;
393 }
394
395 switch(changes){
396 case 0: /* Nothing changed. If this packet contains data and the
397 * last one didn't, this is probably a data packet following
398 * an ack (normal on an interactive connection) and we send
399 * it compressed. Otherwise it's probably a retransmit,
400 * retransmitted ack or window probe. Send it uncompressed
401 * in case the other side missed the compressed version.
402 */
403 if(ip->tot_len != cs->cs_ip.tot_len &&
404 ntohs(cs->cs_ip.tot_len) == hlen)
405 break;
406 goto uncompressed;
407 break;
408 case SPECIAL_I:
409 case SPECIAL_D:
410 /* actual changes match one of our special case encodings --
411 * send packet uncompressed.
412 */
413 goto uncompressed;
414 case NEW_S|NEW_A:
415 if(deltaS == deltaA &&
416 deltaS == ntohs(cs->cs_ip.tot_len) - hlen){
417 /* special case for echoed terminal traffic */
418 changes = SPECIAL_I;
419 cp = new_seq;
420 }
421 break;
422 case NEW_S:
423 if(deltaS == ntohs(cs->cs_ip.tot_len) - hlen){
424 /* special case for data xfer */
425 changes = SPECIAL_D;
426 cp = new_seq;
427 }
428 break;
429 }
430 deltaS = ntohs(ip->id) - ntohs(cs->cs_ip.id);
431 if(deltaS != 1){
432 cp = encode(cp,deltaS);
433 changes |= NEW_I;
434 }
435 if(th->psh)
436 changes |= TCP_PUSH_BIT;
437 /* Grab the cksum before we overwrite it below. Then update our
438 * state with this packet's header.
439 */
440 deltaA = ntohs(th->check);
441 memcpy(&cs->cs_ip,ip,20);
442 memcpy(&cs->cs_tcp,th,20);
443 /* We want to use the original packet as our compressed packet.
444 * (cp - new_seq) is the number of bytes we need for compressed
445 * sequence numbers. In addition we need one byte for the change
446 * mask, one for the connection id and two for the tcp checksum.
447 * So, (cp - new_seq) + 4 bytes of header are needed.
448 */
449 deltaS = cp - new_seq;
450 if(compress_cid == 0 || comp->xmit_current != cs->cs_this){
451 cp = ocp;
452 *cpp = ocp;
453 *cp++ = changes | NEW_C;
454 *cp++ = cs->cs_this;
455 comp->xmit_current = cs->cs_this;
456 } else {
457 cp = ocp;
458 *cpp = ocp;
459 *cp++ = changes;
460 }
461 cp = put16(cp,(short)deltaA); /* Write TCP checksum */
462 /* deltaS is now the size of the change section of the compressed header */
463 memcpy(cp,new_seq,deltaS); /* Write list of deltas */
464 memcpy(cp+deltaS,icp+hlen,isize-hlen);
465 comp->sls_o_compressed++;
466 ocp[0] |= SL_TYPE_COMPRESSED_TCP;
467 return isize - hlen + deltaS + (cp - ocp);
468
469 /* Update connection state cs & send uncompressed packet (i.e.,
470 * a regular ip/tcp packet but with the 'conversation id' we hope
471 * to use on future compressed packets in the protocol field).
472 */
473 uncompressed:
474 memcpy(&cs->cs_ip,ip,20);
475 memcpy(&cs->cs_tcp,th,20);
476 if (ip->ihl > 5)
477 memcpy(cs->cs_ipopt, ip+1, ((ip->ihl) - 5) * 4);
478 if (th->doff > 5)
479 memcpy(cs->cs_tcpopt, th+1, ((th->doff) - 5) * 4);
480 comp->xmit_current = cs->cs_this;
481 comp->sls_o_uncompressed++;
482 memcpy(ocp, icp, isize);
483 *cpp = ocp;
484 ocp[9] = cs->cs_this;
485 ocp[0] |= SL_TYPE_UNCOMPRESSED_TCP;
486 return isize;
487 }
488
489
490 int
491 slhc_uncompress(struct slcompress *comp, unsigned char *icp, int isize)
/* */
492 {
493 register int changes;
494 long x;
495 register struct tcphdr *thp;
496 register struct iphdr *ip;
497 register struct cstate *cs;
498 int len, hdrlen;
499 unsigned char *cp = icp;
500
501 /* We've got a compressed packet; read the change byte */
502 comp->sls_i_compressed++;
503 if(isize < 3){
504 comp->sls_i_error++;
505 return 0;
506 }
507 changes = *cp++;
508 if(changes & NEW_C){
509 /* Make sure the state index is in range, then grab the state.
510 * If we have a good state index, clear the 'discard' flag.
511 */
512 x = *cp++; /* Read conn index */
513 if(x < 0 || x > comp->rslot_limit)
514 goto bad;
515
516 comp->flags &=~ SLF_TOSS;
517 comp->recv_current = x;
518 } else {
519 /* this packet has an implicit state index. If we've
520 * had a line error since the last time we got an
521 * explicit state index, we have to toss the packet. */
522 if(comp->flags & SLF_TOSS){
523 comp->sls_i_tossed++;
524 return 0;
525 }
526 }
527 cs = &comp->rstate[comp->recv_current];
528 thp = &cs->cs_tcp;
529 ip = &cs->cs_ip;
530
531 if((x = pull16(&cp)) == -1) { /* Read the TCP checksum */
532 goto bad;
533 }
534 thp->check = htons(x);
535
536 thp->psh = (changes & TCP_PUSH_BIT) ? 1 : 0;
537 /*
538 * we can use the same number for the length of the saved header and
539 * the current one, because the packet wouldn't have been sent
540 * as compressed unless the options were the same as the previous one
541 */
542
543 hdrlen = ip->ihl * 4 + thp->doff * 4;
544
545 switch(changes & SPECIALS_MASK){
546 case SPECIAL_I: /* Echoed terminal traffic */
547 {
548 register short i;
549 i = ntohs(ip->tot_len) - hdrlen;
550 thp->ack_seq = htonl( ntohl(thp->ack_seq) + i);
551 thp->seq = htonl( ntohl(thp->seq) + i);
552 }
553 break;
554
555 case SPECIAL_D: /* Unidirectional data */
556 thp->seq = htonl( ntohl(thp->seq) +
557 ntohs(ip->tot_len) - hdrlen);
558 break;
559
560 default:
561 if(changes & NEW_U){
562 thp->urg = 1;
563 if((x = decode(&cp)) == -1) {
564 goto bad;
565 }
566 thp->urg_ptr = htons(x);
567 } else
568 thp->urg = 0;
569 if(changes & NEW_W){
570 if((x = decode(&cp)) == -1) {
571 goto bad;
572 }
573 thp->window = htons( ntohs(thp->window) + x);
574 }
575 if(changes & NEW_A){
576 if((x = decode(&cp)) == -1) {
577 goto bad;
578 }
579 thp->ack_seq = htonl( ntohl(thp->ack_seq) + x);
580 }
581 if(changes & NEW_S){
582 if((x = decode(&cp)) == -1) {
583 goto bad;
584 }
585 thp->seq = htonl( ntohl(thp->seq) + x);
586 }
587 break;
588 }
589 if(changes & NEW_I){
590 if((x = decode(&cp)) == -1) {
591 goto bad;
592 }
593 ip->id = htons (ntohs (ip->id) + x);
594 } else
595 ip->id = htons (ntohs (ip->id) + 1);
596
597 /*
598 * At this point, cp points to the first byte of data in the
599 * packet. Put the reconstructed TCP and IP headers back on the
600 * packet. Recalculate IP checksum (but not TCP checksum).
601 */
602
603 len = isize - (cp - icp);
604 if (len < 0)
605 goto bad;
606 len += hdrlen;
607 ip->tot_len = htons(len);
608 ip->check = 0;
609
610 memmove(icp + hdrlen, cp, len - hdrlen);
611
612 cp = icp;
613 memcpy(cp, ip, 20);
614 cp += 20;
615
616 if (ip->ihl > 5) {
617 memcpy(cp, cs->cs_ipopt, (ip->ihl - 5) * 4);
618 cp += (ip->ihl - 5) * 4;
619 }
620
621 #ifdef __alpha__
622 stw_u(ip_fast_csum(icp, ip->ihl), &((struct iphdr *)icp)->check);
623 #else
624 ((struct iphdr *)icp)->check = ip_fast_csum(icp, ((struct iphdr*)icp)->ihl);
625 #endif
626
627 memcpy(cp, thp, 20);
628 cp += 20;
629
630 if (thp->doff > 5) {
631 memcpy(cp, cs->cs_tcpopt, ((thp->doff) - 5) * 4);
632 cp += ((thp->doff) - 5) * 4;
633 }
634
635 return len;
636 bad:
637 comp->sls_i_error++;
638 return slhc_toss( comp );
639 }
640
641
642 int
643 slhc_remember(struct slcompress *comp, unsigned char *icp, int isize)
/* */
644 {
645 register struct cstate *cs;
646 unsigned ihl;
647
648 unsigned char index;
649
650 if(isize < 20) {
651 /* The packet is shorter than a legal IP header */
652 comp->sls_i_runt++;
653 return slhc_toss( comp );
654 }
655 /* Peek at the IP header's IHL field to find its length */
656 ihl = icp[0] & 0xf;
657 if(ihl < 20 / 4){
658 /* The IP header length field is too small */
659 comp->sls_i_runt++;
660 return slhc_toss( comp );
661 }
662 index = icp[9];
663 icp[9] = IPPROTO_TCP;
664
665 if (ip_fast_csum(icp, ihl)) {
666 /* Bad IP header checksum; discard */
667 comp->sls_i_badcheck++;
668 return slhc_toss( comp );
669 }
670 if(index > comp->rslot_limit) {
671 comp->sls_i_error++;
672 return slhc_toss(comp);
673 }
674
675 /* Update local state */
676 cs = &comp->rstate[comp->recv_current = index];
677 comp->flags &=~ SLF_TOSS;
678 memcpy(&cs->cs_ip,icp,20);
679 memcpy(&cs->cs_tcp,icp + ihl*4,20);
680 if (ihl > 5)
681 memcpy(cs->cs_ipopt, icp + sizeof(struct iphdr), (ihl - 5) * 4);
682 if (cs->cs_tcp.doff > 5)
683 memcpy(cs->cs_tcpopt, icp + ihl*4 + sizeof(struct tcphdr), (cs->cs_tcp.doff - 5) * 4);
684 cs->cs_hsize = ihl*2 + cs->cs_tcp.doff*2;
685 /* Put headers back on packet
686 * Neither header checksum is recalculated
687 */
688 comp->sls_i_uncompressed++;
689 return isize;
690 }
691
692
693 int
694 slhc_toss(struct slcompress *comp)
/* */
695 {
696 if ( comp == NULLSLCOMPR )
697 return 0;
698
699 comp->flags |= SLF_TOSS;
700 return 0;
701 }
702
703
704 void slhc_i_status(struct slcompress *comp)
/* */
705 {
706 if (comp != NULLSLCOMPR) {
707 printk("\t%ld Cmp, %ld Uncmp, %ld Bad, %ld Tossed\n",
708 comp->sls_i_compressed,
709 comp->sls_i_uncompressed,
710 comp->sls_i_error,
711 comp->sls_i_tossed);
712 }
713 }
714
715
716 void slhc_o_status(struct slcompress *comp)
/* */
717 {
718 if (comp != NULLSLCOMPR) {
719 printk("\t%ld Cmp, %ld Uncmp, %ld AsIs, %ld NotTCP\n",
720 comp->sls_o_compressed,
721 comp->sls_o_uncompressed,
722 comp->sls_o_tcp,
723 comp->sls_o_nontcp);
724 printk("\t%10ld Searches, %10ld Misses\n",
725 comp->sls_o_searches,
726 comp->sls_o_misses);
727 }
728 }
729
730 #ifdef MODULE
731
732 int init_module(void)
/* */
733 {
734 printk("CSLIP: code copyright 1989 Regents of the University of California\n");
735 return 0;
736 }
737
738 void cleanup_module(void)
/* ![[last]](../icons/n_last.png)
*/
739 {
740 return;
741 }
742 #endif /* MODULE */
743 #endif /* CONFIG_INET */
![[bottom]](../icons/n_bottom.png){kind=icon}
*/