Commit | Line | Data |
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b06f22bd | 1 | /* slcompress.c 7.5 90/01/20 */ |
11b5360c | 2 | /* |
11b5360c SL |
3 | * Routines to compress and uncompess tcp packets (for transmission |
4 | * over low speed serial lines. | |
5 | * | |
b06f22bd | 6 | * Copyright (c) 1989 Regents of the University of California. |
11b5360c | 7 | * All rights reserved. |
b06f22bd SL |
8 | * |
9 | * Redistribution and use in source and binary forms are permitted | |
10 | * provided that the above copyright notice and this paragraph are | |
11 | * duplicated in all such forms and that any documentation, | |
12 | * advertising materials, and other materials related to such | |
13 | * distribution and use acknowledge that the software was developed | |
14 | * by the University of California, Berkeley. The name of the | |
15 | * University may not be used to endorse or promote products derived | |
16 | * from this software without specific prior written permission. | |
17 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR | |
18 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED | |
19 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. | |
20 | * | |
21 | * Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989: | |
22 | * - Initial distribution. | |
11b5360c | 23 | */ |
11b5360c | 24 | #ifndef lint |
b06f22bd | 25 | static char rcsid[] = "$Header: slcompress.c,v 1.19 89/12/31 08:52:59 van Exp $"; |
11b5360c SL |
26 | #endif |
27 | ||
28 | #include <sys/types.h> | |
29 | #include <sys/param.h> | |
30 | #include <sys/mbuf.h> | |
31 | #include <netinet/in.h> | |
32 | #include <netinet/in_systm.h> | |
33 | #include <netinet/ip.h> | |
34 | #include <netinet/tcp.h> | |
35 | ||
36 | #include "slcompress.h" | |
37 | ||
b06f22bd | 38 | #ifndef SL_NO_STATS |
1dbf8d66 MK |
39 | #define INCR(counter) ++comp->counter; |
40 | #else | |
41 | #define INCR(counter) | |
42 | #endif | |
11b5360c SL |
43 | |
44 | #define BCMP(p1, p2, n) bcmp((char *)(p1), (char *)(p2), (int)(n)) | |
45 | #define BCOPY(p1, p2, n) bcopy((char *)(p1), (char *)(p2), (int)(n)) | |
b06f22bd SL |
46 | #ifndef KERNEL |
47 | #define ovbcopy bcopy | |
48 | #endif | |
11b5360c | 49 | |
11b5360c SL |
50 | |
51 | void | |
52 | sl_compress_init(comp) | |
53 | struct slcompress *comp; | |
54 | { | |
55 | register u_int i; | |
56 | register struct cstate *tstate = comp->tstate; | |
57 | ||
58 | bzero((char *)comp, sizeof(*comp)); | |
59 | for (i = MAX_STATES - 1; i > 0; --i) { | |
60 | tstate[i].cs_id = i; | |
61 | tstate[i].cs_next = &tstate[i - 1]; | |
62 | } | |
63 | tstate[0].cs_next = &tstate[MAX_STATES - 1]; | |
64 | tstate[0].cs_id = 0; | |
65 | comp->last_cs = &tstate[0]; | |
66 | comp->last_recv = 255; | |
67 | comp->last_xmit = 255; | |
68 | } | |
69 | ||
70 | ||
71 | /* ENCODE encodes a number that is known to be non-zero. ENCODEZ | |
72 | * checks for zero (since zero has to be encoded in the long, 3 byte | |
73 | * form). | |
74 | */ | |
75 | #define ENCODE(n) { \ | |
76 | if ((u_short)(n) >= 256) { \ | |
77 | *cp++ = 0; \ | |
78 | cp[1] = (n); \ | |
79 | cp[0] = (n) >> 8; \ | |
80 | cp += 2; \ | |
81 | } else { \ | |
82 | *cp++ = (n); \ | |
83 | } \ | |
84 | } | |
85 | #define ENCODEZ(n) { \ | |
86 | if ((u_short)(n) >= 256 || (u_short)(n) == 0) { \ | |
87 | *cp++ = 0; \ | |
88 | cp[1] = (n); \ | |
89 | cp[0] = (n) >> 8; \ | |
90 | cp += 2; \ | |
91 | } else { \ | |
92 | *cp++ = (n); \ | |
93 | } \ | |
94 | } | |
95 | ||
96 | #define DECODEL(f) { \ | |
97 | if (*cp == 0) {\ | |
98 | (f) = htonl(ntohl(f) + ((cp[1] << 8) | cp[2])); \ | |
99 | cp += 3; \ | |
100 | } else { \ | |
101 | (f) = htonl(ntohl(f) + (u_long)*cp++); \ | |
102 | } \ | |
103 | } | |
104 | ||
105 | #define DECODES(f) { \ | |
106 | if (*cp == 0) {\ | |
107 | (f) = htons(ntohs(f) + ((cp[1] << 8) | cp[2])); \ | |
108 | cp += 3; \ | |
109 | } else { \ | |
110 | (f) = htons(ntohs(f) + (u_long)*cp++); \ | |
111 | } \ | |
112 | } | |
113 | ||
b06f22bd SL |
114 | #define DECODEU(f) { \ |
115 | if (*cp == 0) {\ | |
116 | (f) = htons((cp[1] << 8) | cp[2]); \ | |
117 | cp += 3; \ | |
118 | } else { \ | |
119 | (f) = htons((u_long)*cp++); \ | |
120 | } \ | |
121 | } | |
122 | ||
11b5360c SL |
123 | |
124 | u_char | |
b06f22bd | 125 | sl_compress_tcp(m, ip, comp, compress_cid) |
11b5360c SL |
126 | struct mbuf *m; |
127 | register struct ip *ip; | |
128 | struct slcompress *comp; | |
b06f22bd | 129 | int compress_cid; |
11b5360c SL |
130 | { |
131 | register struct cstate *cs = comp->last_cs->cs_next; | |
132 | register u_int hlen = ip->ip_hl; | |
133 | register struct tcphdr *oth; | |
134 | register struct tcphdr *th; | |
135 | register u_int deltaS, deltaA; | |
136 | register u_int changes = 0; | |
137 | u_char new_seq[16]; | |
138 | register u_char *cp = new_seq; | |
139 | ||
140 | /* | |
b06f22bd SL |
141 | * Bail if this is an IP fragment or if the TCP packet isn't |
142 | * `compressible' (i.e., ACK isn't set or some other control bit is | |
143 | * set). (We assume that the caller has already made sure the | |
144 | * packet is IP proto TCP). | |
11b5360c | 145 | */ |
b06f22bd | 146 | if ((ip->ip_off & htons(0x3fff)) || m->m_len < 40) |
11b5360c SL |
147 | return (TYPE_IP); |
148 | ||
149 | th = (struct tcphdr *)&((int *)ip)[hlen]; | |
150 | if ((th->th_flags & (TH_SYN|TH_FIN|TH_RST|TH_ACK)) != TH_ACK) | |
151 | return (TYPE_IP); | |
b06f22bd SL |
152 | /* |
153 | * Packet is compressible -- we're going to send either a | |
154 | * COMPRESSED_TCP or UNCOMPRESSED_TCP packet. Either way we need | |
155 | * to locate (or create) the connection state. Special case the | |
156 | * most recently used connection since it's most likely to be used | |
157 | * again & we don't have to do any reordering if it's used. | |
158 | */ | |
1dbf8d66 MK |
159 | INCR(sls_packets) |
160 | if (ip->ip_src.s_addr != cs->cs_ip.ip_src.s_addr || | |
161 | ip->ip_dst.s_addr != cs->cs_ip.ip_dst.s_addr || | |
162 | *(int *)th != ((int *)&cs->cs_ip)[cs->cs_ip.ip_hl]) { | |
11b5360c SL |
163 | /* |
164 | * Wasn't the first -- search for it. | |
165 | * | |
166 | * States are kept in a circularly linked list with | |
b06f22bd | 167 | * last_cs pointing to the end of the list. The |
11b5360c SL |
168 | * list is kept in lru order by moving a state to the |
169 | * head of the list whenever it is referenced. Since | |
170 | * the list is short and, empirically, the connection | |
171 | * we want is almost always near the front, we locate | |
172 | * states via linear search. If we don't find a state | |
b06f22bd | 173 | * for the datagram, the oldest state is (re-)used. |
11b5360c SL |
174 | */ |
175 | register struct cstate *lcs; | |
b06f22bd | 176 | register struct cstate *lastcs = comp->last_cs; |
11b5360c SL |
177 | |
178 | do { | |
179 | lcs = cs; cs = cs->cs_next; | |
1dbf8d66 | 180 | INCR(sls_searches) |
b06f22bd SL |
181 | if (ip->ip_src.s_addr == cs->cs_ip.ip_src.s_addr |
182 | && ip->ip_dst.s_addr == cs->cs_ip.ip_dst.s_addr | |
183 | && *(int *)th == ((int *)&cs->cs_ip)[cs->cs_ip.ip_hl]) | |
11b5360c | 184 | goto found; |
b06f22bd | 185 | } while (cs != lastcs); |
11b5360c SL |
186 | |
187 | /* | |
b06f22bd SL |
188 | * Didn't find it -- re-use oldest cstate. Send an |
189 | * uncompressed packet that tells the other side what | |
190 | * connection number we're using for this conversation. | |
191 | * Note that since the state list is circular, the oldest | |
192 | * state points to the newest and we only need to set | |
193 | * last_cs to update the lru linkage. | |
11b5360c | 194 | */ |
b06f22bd | 195 | INCR(sls_misses) |
11b5360c SL |
196 | comp->last_cs = lcs; |
197 | hlen += th->th_off; | |
198 | hlen <<= 2; | |
199 | goto uncompressed; | |
200 | ||
201 | found: | |
202 | /* | |
203 | * Found it -- move to the front on the connection list. | |
204 | */ | |
b06f22bd | 205 | if (cs == lastcs) |
11b5360c SL |
206 | comp->last_cs = lcs; |
207 | else { | |
208 | lcs->cs_next = cs->cs_next; | |
b06f22bd SL |
209 | cs->cs_next = lastcs->cs_next; |
210 | lastcs->cs_next = cs; | |
11b5360c SL |
211 | } |
212 | } | |
213 | ||
214 | /* | |
b06f22bd SL |
215 | * Make sure that only what we expect to change changed. The first |
216 | * line of the `if' checks the IP protocol version, header length & | |
217 | * type of service. The 2nd line checks the "Don't fragment" bit. | |
218 | * The 3rd line checks the time-to-live and protocol (the protocol | |
219 | * check is unnecessary but costless). The 4th line checks the TCP | |
220 | * header length. The 5th line checks IP options, if any. The 6th | |
221 | * line checks TCP options, if any. If any of these things are | |
222 | * different between the previous & current datagram, we send the | |
223 | * current datagram `uncompressed'. | |
11b5360c SL |
224 | */ |
225 | oth = (struct tcphdr *)&((int *)&cs->cs_ip)[hlen]; | |
226 | deltaS = hlen; | |
227 | hlen += th->th_off; | |
228 | hlen <<= 2; | |
229 | ||
230 | if (((u_short *)ip)[0] != ((u_short *)&cs->cs_ip)[0] || | |
b06f22bd | 231 | ((u_short *)ip)[3] != ((u_short *)&cs->cs_ip)[3] || |
11b5360c SL |
232 | ((u_short *)ip)[4] != ((u_short *)&cs->cs_ip)[4] || |
233 | th->th_off != oth->th_off || | |
234 | (deltaS > 5 && | |
235 | BCMP(ip + 1, &cs->cs_ip + 1, (deltaS - 5) << 2)) || | |
236 | (th->th_off > 5 && | |
237 | BCMP(th + 1, oth + 1, (th->th_off - 5) << 2))) | |
238 | goto uncompressed; | |
239 | ||
240 | /* | |
241 | * Figure out which of the changing fields changed. The | |
242 | * receiver expects changes in the order: urgent, window, | |
243 | * ack, seq (the order minimizes the number of temporaries | |
244 | * needed in this section of code). | |
245 | */ | |
246 | if (th->th_flags & TH_URG) { | |
247 | deltaS = ntohs(th->th_urp); | |
248 | ENCODEZ(deltaS); | |
249 | changes |= NEW_U; | |
250 | } else if (th->th_urp != oth->th_urp) | |
251 | /* argh! URG not set but urp changed -- a sensible | |
252 | * implementation should never do this but RFC793 | |
253 | * doesn't prohibit the change so we have to deal | |
b06f22bd | 254 | * with it. */ |
11b5360c SL |
255 | goto uncompressed; |
256 | ||
257 | if (deltaS = (u_short)(ntohs(th->th_win) - ntohs(oth->th_win))) { | |
258 | ENCODE(deltaS); | |
259 | changes |= NEW_W; | |
260 | } | |
261 | ||
262 | if (deltaA = ntohl(th->th_ack) - ntohl(oth->th_ack)) { | |
263 | if (deltaA > 0xffff) | |
264 | goto uncompressed; | |
265 | ENCODE(deltaA); | |
266 | changes |= NEW_A; | |
267 | } | |
268 | ||
269 | if (deltaS = ntohl(th->th_seq) - ntohl(oth->th_seq)) { | |
270 | if (deltaS > 0xffff) | |
271 | goto uncompressed; | |
272 | ENCODE(deltaS); | |
273 | changes |= NEW_S; | |
274 | } | |
275 | ||
276 | switch(changes) { | |
277 | ||
278 | case 0: | |
11b5360c | 279 | /* |
b06f22bd SL |
280 | * Nothing changed. If this packet contains data and the |
281 | * last one didn't, this is probably a data packet following | |
282 | * an ack (normal on an interactive connection) and we send | |
283 | * it compressed. Otherwise it's probably a retransmit, | |
284 | * retransmitted ack or window probe. Send it uncompressed | |
285 | * in case the other side missed the compressed version. | |
11b5360c | 286 | */ |
b06f22bd SL |
287 | if (ip->ip_len != cs->cs_ip.ip_len && |
288 | ntohs(cs->cs_ip.ip_len) == hlen) | |
289 | break; | |
290 | ||
291 | /* (fall through) */ | |
11b5360c SL |
292 | |
293 | case SPECIAL_I: | |
294 | case SPECIAL_D: | |
295 | /* | |
296 | * actual changes match one of our special case encodings -- | |
297 | * send packet uncompressed. | |
298 | */ | |
299 | goto uncompressed; | |
300 | ||
301 | case NEW_S|NEW_A: | |
302 | if (deltaS == deltaA && | |
303 | deltaS == ntohs(cs->cs_ip.ip_len) - hlen) { | |
304 | /* special case for echoed terminal traffic */ | |
305 | changes = SPECIAL_I; | |
306 | cp = new_seq; | |
307 | } | |
308 | break; | |
309 | ||
310 | case NEW_S: | |
311 | if (deltaS == ntohs(cs->cs_ip.ip_len) - hlen) { | |
312 | /* special case for data xfer */ | |
313 | changes = SPECIAL_D; | |
314 | cp = new_seq; | |
315 | } | |
316 | break; | |
317 | } | |
318 | ||
319 | deltaS = ntohs(ip->ip_id) - ntohs(cs->cs_ip.ip_id); | |
320 | if (deltaS != 1) { | |
321 | ENCODEZ(deltaS); | |
322 | changes |= NEW_I; | |
323 | } | |
324 | if (th->th_flags & TH_PUSH) | |
325 | changes |= TCP_PUSH_BIT; | |
326 | /* | |
327 | * Grab the cksum before we overwrite it below. Then update our | |
328 | * state with this packet's header. | |
329 | */ | |
330 | deltaA = ntohs(th->th_sum); | |
331 | BCOPY(ip, &cs->cs_ip, hlen); | |
332 | ||
333 | /* | |
334 | * We want to use the original packet as our compressed packet. | |
335 | * (cp - new_seq) is the number of bytes we need for compressed | |
336 | * sequence numbers. In addition we need one byte for the change | |
337 | * mask, one for the connection id and two for the tcp checksum. | |
338 | * So, (cp - new_seq) + 4 bytes of header are needed. hlen is how | |
339 | * many bytes of the original packet to toss so subtract the two to | |
340 | * get the new packet size. | |
341 | */ | |
342 | deltaS = cp - new_seq; | |
343 | cp = (u_char *)ip; | |
b06f22bd | 344 | if (compress_cid == 0 || comp->last_xmit != cs->cs_id) { |
11b5360c SL |
345 | comp->last_xmit = cs->cs_id; |
346 | hlen -= deltaS + 4; | |
1dbf8d66 | 347 | cp += hlen; |
1dbf8d66 | 348 | *cp++ = changes | NEW_C; |
11b5360c SL |
349 | *cp++ = cs->cs_id; |
350 | } else { | |
351 | hlen -= deltaS + 3; | |
1dbf8d66 | 352 | cp += hlen; |
1dbf8d66 | 353 | *cp++ = changes; |
11b5360c | 354 | } |
b06f22bd SL |
355 | m->m_len -= hlen; |
356 | m->m_data += hlen; | |
11b5360c SL |
357 | *cp++ = deltaA >> 8; |
358 | *cp++ = deltaA; | |
359 | BCOPY(new_seq, cp, deltaS); | |
1dbf8d66 | 360 | INCR(sls_compressed) |
11b5360c SL |
361 | return (TYPE_COMPRESSED_TCP); |
362 | ||
363 | /* | |
364 | * Update connection state cs & send uncompressed packet ('uncompressed' | |
365 | * means a regular ip/tcp packet but with the 'conversation id' we hope | |
366 | * to use on future compressed packets in the protocol field). | |
367 | */ | |
368 | uncompressed: | |
369 | BCOPY(ip, &cs->cs_ip, hlen); | |
370 | ip->ip_p = cs->cs_id; | |
371 | comp->last_xmit = cs->cs_id; | |
11b5360c SL |
372 | return (TYPE_UNCOMPRESSED_TCP); |
373 | } | |
374 | ||
11b5360c | 375 | |
1dbf8d66 MK |
376 | int |
377 | sl_uncompress_tcp(bufp, len, type, comp) | |
378 | u_char **bufp; | |
379 | int len; | |
380 | u_int type; | |
11b5360c SL |
381 | struct slcompress *comp; |
382 | { | |
383 | register u_char *cp; | |
384 | register u_int hlen, changes; | |
385 | register struct tcphdr *th; | |
386 | register struct cstate *cs; | |
387 | register struct ip *ip; | |
11b5360c SL |
388 | |
389 | switch (type) { | |
390 | ||
391 | case TYPE_UNCOMPRESSED_TCP: | |
1dbf8d66 | 392 | ip = (struct ip *) *bufp; |
b06f22bd SL |
393 | if (ip->ip_p >= MAX_STATES) |
394 | goto bad; | |
11b5360c SL |
395 | cs = &comp->rstate[comp->last_recv = ip->ip_p]; |
396 | comp->flags &=~ SLF_TOSS; | |
397 | ip->ip_p = IPPROTO_TCP; | |
398 | hlen = ip->ip_hl; | |
399 | hlen += ((struct tcphdr *)&((int *)ip)[hlen])->th_off; | |
400 | hlen <<= 2; | |
401 | BCOPY(ip, &cs->cs_ip, hlen); | |
402 | cs->cs_ip.ip_sum = 0; | |
403 | cs->cs_hlen = hlen; | |
1dbf8d66 MK |
404 | INCR(sls_uncompressedin) |
405 | return (len); | |
11b5360c | 406 | |
1dbf8d66 | 407 | default: |
b06f22bd | 408 | goto bad; |
11b5360c SL |
409 | |
410 | case TYPE_COMPRESSED_TCP: | |
11b5360c SL |
411 | break; |
412 | } | |
413 | /* We've got a compressed packet. */ | |
1dbf8d66 MK |
414 | INCR(sls_compressedin) |
415 | cp = *bufp; | |
11b5360c SL |
416 | changes = *cp++; |
417 | if (changes & NEW_C) { | |
418 | /* Make sure the state index is in range, then grab the state. | |
419 | * If we have a good state index, clear the 'discard' flag. */ | |
b06f22bd SL |
420 | if (*cp >= MAX_STATES) |
421 | goto bad; | |
422 | ||
11b5360c SL |
423 | comp->flags &=~ SLF_TOSS; |
424 | comp->last_recv = *cp++; | |
425 | } else { | |
426 | /* this packet has an implicit state index. If we've | |
427 | * had a line error since the last time we got an | |
428 | * explicit state index, we have to toss the packet. */ | |
1dbf8d66 MK |
429 | if (comp->flags & SLF_TOSS) { |
430 | INCR(sls_tossed) | |
431 | return (0); | |
432 | } | |
11b5360c SL |
433 | } |
434 | cs = &comp->rstate[comp->last_recv]; | |
435 | hlen = cs->cs_ip.ip_hl << 2; | |
436 | th = (struct tcphdr *)&((u_char *)&cs->cs_ip)[hlen]; | |
437 | th->th_sum = htons((*cp << 8) | cp[1]); | |
438 | cp += 2; | |
439 | if (changes & TCP_PUSH_BIT) | |
440 | th->th_flags |= TH_PUSH; | |
441 | else | |
442 | th->th_flags &=~ TH_PUSH; | |
443 | ||
444 | switch (changes & SPECIALS_MASK) { | |
445 | case SPECIAL_I: | |
446 | { | |
447 | register u_int i = ntohs(cs->cs_ip.ip_len) - cs->cs_hlen; | |
448 | th->th_ack = htonl(ntohl(th->th_ack) + i); | |
449 | th->th_seq = htonl(ntohl(th->th_seq) + i); | |
450 | } | |
451 | break; | |
452 | ||
453 | case SPECIAL_D: | |
454 | th->th_seq = htonl(ntohl(th->th_seq) + ntohs(cs->cs_ip.ip_len) | |
455 | - cs->cs_hlen); | |
456 | break; | |
457 | ||
458 | default: | |
459 | if (changes & NEW_U) { | |
460 | th->th_flags |= TH_URG; | |
b06f22bd | 461 | DECODEU(th->th_urp) |
11b5360c SL |
462 | } else |
463 | th->th_flags &=~ TH_URG; | |
464 | if (changes & NEW_W) | |
465 | DECODES(th->th_win) | |
466 | if (changes & NEW_A) | |
467 | DECODEL(th->th_ack) | |
468 | if (changes & NEW_S) | |
469 | DECODEL(th->th_seq) | |
470 | break; | |
471 | } | |
472 | if (changes & NEW_I) { | |
473 | DECODES(cs->cs_ip.ip_id) | |
474 | } else | |
475 | cs->cs_ip.ip_id = htons(ntohs(cs->cs_ip.ip_id) + 1); | |
476 | ||
477 | /* | |
478 | * At this point, cp points to the first byte of data in the | |
1dbf8d66 MK |
479 | * packet. If we're not aligned on a 4-byte boundary, copy the |
480 | * data down so the ip & tcp headers will be aligned. Then back up | |
481 | * cp by the tcp/ip header length to make room for the reconstructed | |
482 | * header (we assume the packet we were handed has enough space to | |
b06f22bd | 483 | * prepend 128 bytes of header). Adjust the length to account for |
1dbf8d66 | 484 | * the new header & fill in the IP total length. |
11b5360c | 485 | */ |
1dbf8d66 | 486 | len -= (cp - *bufp); |
b06f22bd | 487 | if (len < 0) |
1dbf8d66 MK |
488 | /* we must have dropped some characters (crc should detect |
489 | * this but the old slip framing won't) */ | |
b06f22bd SL |
490 | goto bad; |
491 | ||
26fea0bf SL |
492 | if ((int)cp & 3) { |
493 | if (len > 0) | |
b06f22bd | 494 | (void) ovbcopy(cp, (caddr_t)((int)cp &~ 3), len); |
1dbf8d66 MK |
495 | cp = (u_char *)((int)cp &~ 3); |
496 | } | |
497 | cp -= cs->cs_hlen; | |
498 | len += cs->cs_hlen; | |
499 | cs->cs_ip.ip_len = htons(len); | |
500 | BCOPY(&cs->cs_ip, cp, cs->cs_hlen); | |
501 | *bufp = cp; | |
502 | ||
503 | /* recompute the ip header checksum */ | |
504 | { | |
505 | register u_short *bp = (u_short *)cp; | |
506 | for (changes = 0; hlen > 0; hlen -= 2) | |
507 | changes += *bp++; | |
508 | changes = (changes & 0xffff) + (changes >> 16); | |
509 | changes = (changes & 0xffff) + (changes >> 16); | |
510 | ((struct ip *)cp)->ip_sum = ~ changes; | |
511 | } | |
512 | return (len); | |
b06f22bd SL |
513 | bad: |
514 | comp->flags |= SLF_TOSS; | |
515 | INCR(sls_errorin) | |
516 | return (0); | |
11b5360c | 517 | } |