Racelogic / Mbed 2 deprecated VIPS_LTC_RAW_IMU

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Dependencies:   BufferedSerial FatFileSystemCpp mbed

EthernetInterface/lwip/netif/ppp/vj.c@66:066b16c6c34f, 2021-11-16 (annotated)

Committer:
JamieB
Date:
Tue Nov 16 19:01:34 2021 +0000
Revision:
66:066b16c6c34f
Parent:
22:0dd9c1b5664a 
Changed Buffered Serial to Read Raw Serial in RX Interrupt

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AndyA 22:0dd9c1b5664a 1 /*
AndyA 22:0dd9c1b5664a 2 * Routines to compress and uncompess tcp packets (for transmission
AndyA 22:0dd9c1b5664a 3 * over low speed serial lines.
AndyA 22:0dd9c1b5664a 4 *
AndyA 22:0dd9c1b5664a 5 * Copyright (c) 1989 Regents of the University of California.
AndyA 22:0dd9c1b5664a 6 * All rights reserved.
AndyA 22:0dd9c1b5664a 7 *
AndyA 22:0dd9c1b5664a 8 * Redistribution and use in source and binary forms are permitted
AndyA 22:0dd9c1b5664a 9 * provided that the above copyright notice and this paragraph are
AndyA 22:0dd9c1b5664a 10 * duplicated in all such forms and that any documentation,
AndyA 22:0dd9c1b5664a 11 * advertising materials, and other materials related to such
AndyA 22:0dd9c1b5664a 12 * distribution and use acknowledge that the software was developed
AndyA 22:0dd9c1b5664a 13 * by the University of California, Berkeley. The name of the
AndyA 22:0dd9c1b5664a 14 * University may not be used to endorse or promote products derived
AndyA 22:0dd9c1b5664a 15 * from this software without specific prior written permission.
AndyA 22:0dd9c1b5664a 16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
AndyA 22:0dd9c1b5664a 17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
AndyA 22:0dd9c1b5664a 18 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
AndyA 22:0dd9c1b5664a 19 *
AndyA 22:0dd9c1b5664a 20 * Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989:
AndyA 22:0dd9c1b5664a 21 * Initial distribution.
AndyA 22:0dd9c1b5664a 22 *
AndyA 22:0dd9c1b5664a 23 * Modified June 1993 by Paul Mackerras, paulus@cs.anu.edu.au,
AndyA 22:0dd9c1b5664a 24 * so that the entire packet being decompressed doesn't have
AndyA 22:0dd9c1b5664a 25 * to be in contiguous memory (just the compressed header).
AndyA 22:0dd9c1b5664a 26 *
AndyA 22:0dd9c1b5664a 27 * Modified March 1998 by Guy Lancaster, glanca@gesn.com,
AndyA 22:0dd9c1b5664a 28 * for a 16 bit processor.
AndyA 22:0dd9c1b5664a 29 */
AndyA 22:0dd9c1b5664a 30
AndyA 22:0dd9c1b5664a 31 #include "lwip/opt.h"
AndyA 22:0dd9c1b5664a 32
AndyA 22:0dd9c1b5664a 33 #if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
AndyA 22:0dd9c1b5664a 34
AndyA 22:0dd9c1b5664a 35 #include "ppp.h"
AndyA 22:0dd9c1b5664a 36 #include "pppdebug.h"
AndyA 22:0dd9c1b5664a 37
AndyA 22:0dd9c1b5664a 38 #include "vj.h"
AndyA 22:0dd9c1b5664a 39
AndyA 22:0dd9c1b5664a 40 #include <string.h>
AndyA 22:0dd9c1b5664a 41
AndyA 22:0dd9c1b5664a 42 #if VJ_SUPPORT
AndyA 22:0dd9c1b5664a 43
AndyA 22:0dd9c1b5664a 44 #if LINK_STATS
AndyA 22:0dd9c1b5664a 45 #define INCR(counter) ++comp->stats.counter
AndyA 22:0dd9c1b5664a 46 #else
AndyA 22:0dd9c1b5664a 47 #define INCR(counter)
AndyA 22:0dd9c1b5664a 48 #endif
AndyA 22:0dd9c1b5664a 49
AndyA 22:0dd9c1b5664a 50 void
AndyA 22:0dd9c1b5664a 51 vj_compress_init(struct vjcompress *comp)
AndyA 22:0dd9c1b5664a 52 {
AndyA 22:0dd9c1b5664a 53 register u_char i;
AndyA 22:0dd9c1b5664a 54 register struct cstate *tstate = comp->tstate;
AndyA 22:0dd9c1b5664a 55
AndyA 22:0dd9c1b5664a 56 #if MAX_SLOTS == 0
AndyA 22:0dd9c1b5664a 57 memset((char *)comp, 0, sizeof(*comp));
AndyA 22:0dd9c1b5664a 58 #endif
AndyA 22:0dd9c1b5664a 59 comp->maxSlotIndex = MAX_SLOTS - 1;
AndyA 22:0dd9c1b5664a 60 comp->compressSlot = 0; /* Disable slot ID compression by default. */
AndyA 22:0dd9c1b5664a 61 for (i = MAX_SLOTS - 1; i > 0; --i) {
AndyA 22:0dd9c1b5664a 62 tstate[i].cs_id = i;
AndyA 22:0dd9c1b5664a 63 tstate[i].cs_next = &tstate[i - 1];
AndyA 22:0dd9c1b5664a 64 }
AndyA 22:0dd9c1b5664a 65 tstate[0].cs_next = &tstate[MAX_SLOTS - 1];
AndyA 22:0dd9c1b5664a 66 tstate[0].cs_id = 0;
AndyA 22:0dd9c1b5664a 67 comp->last_cs = &tstate[0];
AndyA 22:0dd9c1b5664a 68 comp->last_recv = 255;
AndyA 22:0dd9c1b5664a 69 comp->last_xmit = 255;
AndyA 22:0dd9c1b5664a 70 comp->flags = VJF_TOSS;
AndyA 22:0dd9c1b5664a 71 }
AndyA 22:0dd9c1b5664a 72
AndyA 22:0dd9c1b5664a 73
AndyA 22:0dd9c1b5664a 74 /* ENCODE encodes a number that is known to be non-zero. ENCODEZ
AndyA 22:0dd9c1b5664a 75 * checks for zero (since zero has to be encoded in the long, 3 byte
AndyA 22:0dd9c1b5664a 76 * form).
AndyA 22:0dd9c1b5664a 77 */
AndyA 22:0dd9c1b5664a 78 #define ENCODE(n) { \
AndyA 22:0dd9c1b5664a 79 if ((u_short)(n) >= 256) { \
AndyA 22:0dd9c1b5664a 80 *cp++ = 0; \
AndyA 22:0dd9c1b5664a 81 cp[1] = (u_char)(n); \
AndyA 22:0dd9c1b5664a 82 cp[0] = (u_char)((n) >> 8); \
AndyA 22:0dd9c1b5664a 83 cp += 2; \
AndyA 22:0dd9c1b5664a 84 } else { \
AndyA 22:0dd9c1b5664a 85 *cp++ = (u_char)(n); \
AndyA 22:0dd9c1b5664a 86 } \
AndyA 22:0dd9c1b5664a 87 }
AndyA 22:0dd9c1b5664a 88 #define ENCODEZ(n) { \
AndyA 22:0dd9c1b5664a 89 if ((u_short)(n) >= 256 || (u_short)(n) == 0) { \
AndyA 22:0dd9c1b5664a 90 *cp++ = 0; \
AndyA 22:0dd9c1b5664a 91 cp[1] = (u_char)(n); \
AndyA 22:0dd9c1b5664a 92 cp[0] = (u_char)((n) >> 8); \
AndyA 22:0dd9c1b5664a 93 cp += 2; \
AndyA 22:0dd9c1b5664a 94 } else { \
AndyA 22:0dd9c1b5664a 95 *cp++ = (u_char)(n); \
AndyA 22:0dd9c1b5664a 96 } \
AndyA 22:0dd9c1b5664a 97 }
AndyA 22:0dd9c1b5664a 98
AndyA 22:0dd9c1b5664a 99 #define DECODEL(f) { \
AndyA 22:0dd9c1b5664a 100 if (*cp == 0) {\
AndyA 22:0dd9c1b5664a 101 u32_t tmp = ntohl(f) + ((cp[1] << 8) | cp[2]); \
AndyA 22:0dd9c1b5664a 102 (f) = htonl(tmp); \
AndyA 22:0dd9c1b5664a 103 cp += 3; \
AndyA 22:0dd9c1b5664a 104 } else { \
AndyA 22:0dd9c1b5664a 105 u32_t tmp = ntohl(f) + (u32_t)*cp++; \
AndyA 22:0dd9c1b5664a 106 (f) = htonl(tmp); \
AndyA 22:0dd9c1b5664a 107 } \
AndyA 22:0dd9c1b5664a 108 }
AndyA 22:0dd9c1b5664a 109
AndyA 22:0dd9c1b5664a 110 #define DECODES(f) { \
AndyA 22:0dd9c1b5664a 111 if (*cp == 0) {\
AndyA 22:0dd9c1b5664a 112 u_short tmp = ntohs(f) + (((u_short)cp[1] << 8) | cp[2]); \
AndyA 22:0dd9c1b5664a 113 (f) = htons(tmp); \
AndyA 22:0dd9c1b5664a 114 cp += 3; \
AndyA 22:0dd9c1b5664a 115 } else { \
AndyA 22:0dd9c1b5664a 116 u_short tmp = ntohs(f) + (u_short)*cp++; \
AndyA 22:0dd9c1b5664a 117 (f) = htons(tmp); \
AndyA 22:0dd9c1b5664a 118 } \
AndyA 22:0dd9c1b5664a 119 }
AndyA 22:0dd9c1b5664a 120
AndyA 22:0dd9c1b5664a 121 #define DECODEU(f) { \
AndyA 22:0dd9c1b5664a 122 if (*cp == 0) {\
AndyA 22:0dd9c1b5664a 123 (f) = htons(((u_short)cp[1] << 8) | cp[2]); \
AndyA 22:0dd9c1b5664a 124 cp += 3; \
AndyA 22:0dd9c1b5664a 125 } else { \
AndyA 22:0dd9c1b5664a 126 (f) = htons((u_short)*cp++); \
AndyA 22:0dd9c1b5664a 127 } \
AndyA 22:0dd9c1b5664a 128 }
AndyA 22:0dd9c1b5664a 129
AndyA 22:0dd9c1b5664a 130 /*
AndyA 22:0dd9c1b5664a 131 * vj_compress_tcp - Attempt to do Van Jacobson header compression on a
AndyA 22:0dd9c1b5664a 132 * packet. This assumes that nb and comp are not null and that the first
AndyA 22:0dd9c1b5664a 133 * buffer of the chain contains a valid IP header.
AndyA 22:0dd9c1b5664a 134 * Return the VJ type code indicating whether or not the packet was
AndyA 22:0dd9c1b5664a 135 * compressed.
AndyA 22:0dd9c1b5664a 136 */
AndyA 22:0dd9c1b5664a 137 u_int
AndyA 22:0dd9c1b5664a 138 vj_compress_tcp(struct vjcompress *comp, struct pbuf *pb)
AndyA 22:0dd9c1b5664a 139 {
AndyA 22:0dd9c1b5664a 140 register struct ip_hdr *ip = (struct ip_hdr *)pb->payload;
AndyA 22:0dd9c1b5664a 141 register struct cstate *cs = comp->last_cs->cs_next;
AndyA 22:0dd9c1b5664a 142 register u_short hlen = IPH_HL(ip);
AndyA 22:0dd9c1b5664a 143 register struct tcp_hdr *oth;
AndyA 22:0dd9c1b5664a 144 register struct tcp_hdr *th;
AndyA 22:0dd9c1b5664a 145 register u_short deltaS, deltaA;
AndyA 22:0dd9c1b5664a 146 register u_long deltaL;
AndyA 22:0dd9c1b5664a 147 register u_int changes = 0;
AndyA 22:0dd9c1b5664a 148 u_char new_seq[16];
AndyA 22:0dd9c1b5664a 149 register u_char *cp = new_seq;
AndyA 22:0dd9c1b5664a 150
AndyA 22:0dd9c1b5664a 151 /*
AndyA 22:0dd9c1b5664a 152 * Check that the packet is IP proto TCP.
AndyA 22:0dd9c1b5664a 153 */
AndyA 22:0dd9c1b5664a 154 if (IPH_PROTO(ip) != IP_PROTO_TCP) {
AndyA 22:0dd9c1b5664a 155 return (TYPE_IP);
AndyA 22:0dd9c1b5664a 156 }
AndyA 22:0dd9c1b5664a 157
AndyA 22:0dd9c1b5664a 158 /*
AndyA 22:0dd9c1b5664a 159 * Bail if this is an IP fragment or if the TCP packet isn't
AndyA 22:0dd9c1b5664a 160 * `compressible' (i.e., ACK isn't set or some other control bit is
AndyA 22:0dd9c1b5664a 161 * set).
AndyA 22:0dd9c1b5664a 162 */
AndyA 22:0dd9c1b5664a 163 if ((IPH_OFFSET(ip) & PP_HTONS(0x3fff)) || pb->tot_len < 40) {
AndyA 22:0dd9c1b5664a 164 return (TYPE_IP);
AndyA 22:0dd9c1b5664a 165 }
AndyA 22:0dd9c1b5664a 166 th = (struct tcp_hdr *)&((long *)ip)[hlen];
AndyA 22:0dd9c1b5664a 167 if ((TCPH_FLAGS(th) & (TCP_SYN|TCP_FIN|TCP_RST|TCP_ACK)) != TCP_ACK) {
AndyA 22:0dd9c1b5664a 168 return (TYPE_IP);
AndyA 22:0dd9c1b5664a 169 }
AndyA 22:0dd9c1b5664a 170 /*
AndyA 22:0dd9c1b5664a 171 * Packet is compressible -- we're going to send either a
AndyA 22:0dd9c1b5664a 172 * COMPRESSED_TCP or UNCOMPRESSED_TCP packet. Either way we need
AndyA 22:0dd9c1b5664a 173 * to locate (or create) the connection state. Special case the
AndyA 22:0dd9c1b5664a 174 * most recently used connection since it's most likely to be used
AndyA 22:0dd9c1b5664a 175 * again & we don't have to do any reordering if it's used.
AndyA 22:0dd9c1b5664a 176 */
AndyA 22:0dd9c1b5664a 177 INCR(vjs_packets);
AndyA 22:0dd9c1b5664a 178 if (!ip_addr_cmp(&ip->src, &cs->cs_ip.src)
AndyA 22:0dd9c1b5664a 179 || !ip_addr_cmp(&ip->dest, &cs->cs_ip.dest)
AndyA 22:0dd9c1b5664a 180 || *(long *)th != ((long *)&cs->cs_ip)[IPH_HL(&cs->cs_ip)]) {
AndyA 22:0dd9c1b5664a 181 /*
AndyA 22:0dd9c1b5664a 182 * Wasn't the first -- search for it.
AndyA 22:0dd9c1b5664a 183 *
AndyA 22:0dd9c1b5664a 184 * States are kept in a circularly linked list with
AndyA 22:0dd9c1b5664a 185 * last_cs pointing to the end of the list. The
AndyA 22:0dd9c1b5664a 186 * list is kept in lru order by moving a state to the
AndyA 22:0dd9c1b5664a 187 * head of the list whenever it is referenced. Since
AndyA 22:0dd9c1b5664a 188 * the list is short and, empirically, the connection
AndyA 22:0dd9c1b5664a 189 * we want is almost always near the front, we locate
AndyA 22:0dd9c1b5664a 190 * states via linear search. If we don't find a state
AndyA 22:0dd9c1b5664a 191 * for the datagram, the oldest state is (re-)used.
AndyA 22:0dd9c1b5664a 192 */
AndyA 22:0dd9c1b5664a 193 register struct cstate *lcs;
AndyA 22:0dd9c1b5664a 194 register struct cstate *lastcs = comp->last_cs;
AndyA 22:0dd9c1b5664a 195
AndyA 22:0dd9c1b5664a 196 do {
AndyA 22:0dd9c1b5664a 197 lcs = cs; cs = cs->cs_next;
AndyA 22:0dd9c1b5664a 198 INCR(vjs_searches);
AndyA 22:0dd9c1b5664a 199 if (ip_addr_cmp(&ip->src, &cs->cs_ip.src)
AndyA 22:0dd9c1b5664a 200 && ip_addr_cmp(&ip->dest, &cs->cs_ip.dest)
AndyA 22:0dd9c1b5664a 201 && *(long *)th == ((long *)&cs->cs_ip)[IPH_HL(&cs->cs_ip)]) {
AndyA 22:0dd9c1b5664a 202 goto found;
AndyA 22:0dd9c1b5664a 203 }
AndyA 22:0dd9c1b5664a 204 } while (cs != lastcs);
AndyA 22:0dd9c1b5664a 205
AndyA 22:0dd9c1b5664a 206 /*
AndyA 22:0dd9c1b5664a 207 * Didn't find it -- re-use oldest cstate. Send an
AndyA 22:0dd9c1b5664a 208 * uncompressed packet that tells the other side what
AndyA 22:0dd9c1b5664a 209 * connection number we're using for this conversation.
AndyA 22:0dd9c1b5664a 210 * Note that since the state list is circular, the oldest
AndyA 22:0dd9c1b5664a 211 * state points to the newest and we only need to set
AndyA 22:0dd9c1b5664a 212 * last_cs to update the lru linkage.
AndyA 22:0dd9c1b5664a 213 */
AndyA 22:0dd9c1b5664a 214 INCR(vjs_misses);
AndyA 22:0dd9c1b5664a 215 comp->last_cs = lcs;
AndyA 22:0dd9c1b5664a 216 hlen += TCPH_OFFSET(th);
AndyA 22:0dd9c1b5664a 217 hlen <<= 2;
AndyA 22:0dd9c1b5664a 218 /* Check that the IP/TCP headers are contained in the first buffer. */
AndyA 22:0dd9c1b5664a 219 if (hlen > pb->len) {
AndyA 22:0dd9c1b5664a 220 return (TYPE_IP);
AndyA 22:0dd9c1b5664a 221 }
AndyA 22:0dd9c1b5664a 222 goto uncompressed;
AndyA 22:0dd9c1b5664a 223
AndyA 22:0dd9c1b5664a 224 found:
AndyA 22:0dd9c1b5664a 225 /*
AndyA 22:0dd9c1b5664a 226 * Found it -- move to the front on the connection list.
AndyA 22:0dd9c1b5664a 227 */
AndyA 22:0dd9c1b5664a 228 if (cs == lastcs) {
AndyA 22:0dd9c1b5664a 229 comp->last_cs = lcs;
AndyA 22:0dd9c1b5664a 230 } else {
AndyA 22:0dd9c1b5664a 231 lcs->cs_next = cs->cs_next;
AndyA 22:0dd9c1b5664a 232 cs->cs_next = lastcs->cs_next;
AndyA 22:0dd9c1b5664a 233 lastcs->cs_next = cs;
AndyA 22:0dd9c1b5664a 234 }
AndyA 22:0dd9c1b5664a 235 }
AndyA 22:0dd9c1b5664a 236
AndyA 22:0dd9c1b5664a 237 oth = (struct tcp_hdr *)&((long *)&cs->cs_ip)[hlen];
AndyA 22:0dd9c1b5664a 238 deltaS = hlen;
AndyA 22:0dd9c1b5664a 239 hlen += TCPH_OFFSET(th);
AndyA 22:0dd9c1b5664a 240 hlen <<= 2;
AndyA 22:0dd9c1b5664a 241 /* Check that the IP/TCP headers are contained in the first buffer. */
AndyA 22:0dd9c1b5664a 242 if (hlen > pb->len) {
AndyA 22:0dd9c1b5664a 243 PPPDEBUG(LOG_INFO, ("vj_compress_tcp: header len %d spans buffers\n", hlen));
AndyA 22:0dd9c1b5664a 244 return (TYPE_IP);
AndyA 22:0dd9c1b5664a 245 }
AndyA 22:0dd9c1b5664a 246
AndyA 22:0dd9c1b5664a 247 /*
AndyA 22:0dd9c1b5664a 248 * Make sure that only what we expect to change changed. The first
AndyA 22:0dd9c1b5664a 249 * line of the `if' checks the IP protocol version, header length &
AndyA 22:0dd9c1b5664a 250 * type of service. The 2nd line checks the "Don't fragment" bit.
AndyA 22:0dd9c1b5664a 251 * The 3rd line checks the time-to-live and protocol (the protocol
AndyA 22:0dd9c1b5664a 252 * check is unnecessary but costless). The 4th line checks the TCP
AndyA 22:0dd9c1b5664a 253 * header length. The 5th line checks IP options, if any. The 6th
AndyA 22:0dd9c1b5664a 254 * line checks TCP options, if any. If any of these things are
AndyA 22:0dd9c1b5664a 255 * different between the previous & current datagram, we send the
AndyA 22:0dd9c1b5664a 256 * current datagram `uncompressed'.
AndyA 22:0dd9c1b5664a 257 */
AndyA 22:0dd9c1b5664a 258 if (((u_short *)ip)[0] != ((u_short *)&cs->cs_ip)[0]
AndyA 22:0dd9c1b5664a 259 || ((u_short *)ip)[3] != ((u_short *)&cs->cs_ip)[3]
AndyA 22:0dd9c1b5664a 260 || ((u_short *)ip)[4] != ((u_short *)&cs->cs_ip)[4]
AndyA 22:0dd9c1b5664a 261 || TCPH_OFFSET(th) != TCPH_OFFSET(oth)
AndyA 22:0dd9c1b5664a 262 || (deltaS > 5 && BCMP(ip + 1, &cs->cs_ip + 1, (deltaS - 5) << 2))
AndyA 22:0dd9c1b5664a 263 || (TCPH_OFFSET(th) > 5 && BCMP(th + 1, oth + 1, (TCPH_OFFSET(th) - 5) << 2))) {
AndyA 22:0dd9c1b5664a 264 goto uncompressed;
AndyA 22:0dd9c1b5664a 265 }
AndyA 22:0dd9c1b5664a 266
AndyA 22:0dd9c1b5664a 267 /*
AndyA 22:0dd9c1b5664a 268 * Figure out which of the changing fields changed. The
AndyA 22:0dd9c1b5664a 269 * receiver expects changes in the order: urgent, window,
AndyA 22:0dd9c1b5664a 270 * ack, seq (the order minimizes the number of temporaries
AndyA 22:0dd9c1b5664a 271 * needed in this section of code).
AndyA 22:0dd9c1b5664a 272 */
AndyA 22:0dd9c1b5664a 273 if (TCPH_FLAGS(th) & TCP_URG) {
AndyA 22:0dd9c1b5664a 274 deltaS = ntohs(th->urgp);
AndyA 22:0dd9c1b5664a 275 ENCODEZ(deltaS);
AndyA 22:0dd9c1b5664a 276 changes |= NEW_U;
AndyA 22:0dd9c1b5664a 277 } else if (th->urgp != oth->urgp) {
AndyA 22:0dd9c1b5664a 278 /* argh! URG not set but urp changed -- a sensible
AndyA 22:0dd9c1b5664a 279 * implementation should never do this but RFC793
AndyA 22:0dd9c1b5664a 280 * doesn't prohibit the change so we have to deal
AndyA 22:0dd9c1b5664a 281 * with it. */
AndyA 22:0dd9c1b5664a 282 goto uncompressed;
AndyA 22:0dd9c1b5664a 283 }
AndyA 22:0dd9c1b5664a 284
AndyA 22:0dd9c1b5664a 285 if ((deltaS = (u_short)(ntohs(th->wnd) - ntohs(oth->wnd))) != 0) {
AndyA 22:0dd9c1b5664a 286 ENCODE(deltaS);
AndyA 22:0dd9c1b5664a 287 changes |= NEW_W;
AndyA 22:0dd9c1b5664a 288 }
AndyA 22:0dd9c1b5664a 289
AndyA 22:0dd9c1b5664a 290 if ((deltaL = ntohl(th->ackno) - ntohl(oth->ackno)) != 0) {
AndyA 22:0dd9c1b5664a 291 if (deltaL > 0xffff) {
AndyA 22:0dd9c1b5664a 292 goto uncompressed;
AndyA 22:0dd9c1b5664a 293 }
AndyA 22:0dd9c1b5664a 294 deltaA = (u_short)deltaL;
AndyA 22:0dd9c1b5664a 295 ENCODE(deltaA);
AndyA 22:0dd9c1b5664a 296 changes |= NEW_A;
AndyA 22:0dd9c1b5664a 297 }
AndyA 22:0dd9c1b5664a 298
AndyA 22:0dd9c1b5664a 299 if ((deltaL = ntohl(th->seqno) - ntohl(oth->seqno)) != 0) {
AndyA 22:0dd9c1b5664a 300 if (deltaL > 0xffff) {
AndyA 22:0dd9c1b5664a 301 goto uncompressed;
AndyA 22:0dd9c1b5664a 302 }
AndyA 22:0dd9c1b5664a 303 deltaS = (u_short)deltaL;
AndyA 22:0dd9c1b5664a 304 ENCODE(deltaS);
AndyA 22:0dd9c1b5664a 305 changes |= NEW_S;
AndyA 22:0dd9c1b5664a 306 }
AndyA 22:0dd9c1b5664a 307
AndyA 22:0dd9c1b5664a 308 switch(changes) {
AndyA 22:0dd9c1b5664a 309 case 0:
AndyA 22:0dd9c1b5664a 310 /*
AndyA 22:0dd9c1b5664a 311 * Nothing changed. If this packet contains data and the
AndyA 22:0dd9c1b5664a 312 * last one didn't, this is probably a data packet following
AndyA 22:0dd9c1b5664a 313 * an ack (normal on an interactive connection) and we send
AndyA 22:0dd9c1b5664a 314 * it compressed. Otherwise it's probably a retransmit,
AndyA 22:0dd9c1b5664a 315 * retransmitted ack or window probe. Send it uncompressed
AndyA 22:0dd9c1b5664a 316 * in case the other side missed the compressed version.
AndyA 22:0dd9c1b5664a 317 */
AndyA 22:0dd9c1b5664a 318 if (IPH_LEN(ip) != IPH_LEN(&cs->cs_ip) &&
AndyA 22:0dd9c1b5664a 319 ntohs(IPH_LEN(&cs->cs_ip)) == hlen) {
AndyA 22:0dd9c1b5664a 320 break;
AndyA 22:0dd9c1b5664a 321 }
AndyA 22:0dd9c1b5664a 322
AndyA 22:0dd9c1b5664a 323 /* (fall through) */
AndyA 22:0dd9c1b5664a 324
AndyA 22:0dd9c1b5664a 325 case SPECIAL_I:
AndyA 22:0dd9c1b5664a 326 case SPECIAL_D:
AndyA 22:0dd9c1b5664a 327 /*
AndyA 22:0dd9c1b5664a 328 * actual changes match one of our special case encodings --
AndyA 22:0dd9c1b5664a 329 * send packet uncompressed.
AndyA 22:0dd9c1b5664a 330 */
AndyA 22:0dd9c1b5664a 331 goto uncompressed;
AndyA 22:0dd9c1b5664a 332
AndyA 22:0dd9c1b5664a 333 case NEW_S|NEW_A:
AndyA 22:0dd9c1b5664a 334 if (deltaS == deltaA && deltaS == ntohs(IPH_LEN(&cs->cs_ip)) - hlen) {
AndyA 22:0dd9c1b5664a 335 /* special case for echoed terminal traffic */
AndyA 22:0dd9c1b5664a 336 changes = SPECIAL_I;
AndyA 22:0dd9c1b5664a 337 cp = new_seq;
AndyA 22:0dd9c1b5664a 338 }
AndyA 22:0dd9c1b5664a 339 break;
AndyA 22:0dd9c1b5664a 340
AndyA 22:0dd9c1b5664a 341 case NEW_S:
AndyA 22:0dd9c1b5664a 342 if (deltaS == ntohs(IPH_LEN(&cs->cs_ip)) - hlen) {
AndyA 22:0dd9c1b5664a 343 /* special case for data xfer */
AndyA 22:0dd9c1b5664a 344 changes = SPECIAL_D;
AndyA 22:0dd9c1b5664a 345 cp = new_seq;
AndyA 22:0dd9c1b5664a 346 }
AndyA 22:0dd9c1b5664a 347 break;
AndyA 22:0dd9c1b5664a 348 }
AndyA 22:0dd9c1b5664a 349
AndyA 22:0dd9c1b5664a 350 deltaS = (u_short)(ntohs(IPH_ID(ip)) - ntohs(IPH_ID(&cs->cs_ip)));
AndyA 22:0dd9c1b5664a 351 if (deltaS != 1) {
AndyA 22:0dd9c1b5664a 352 ENCODEZ(deltaS);
AndyA 22:0dd9c1b5664a 353 changes |= NEW_I;
AndyA 22:0dd9c1b5664a 354 }
AndyA 22:0dd9c1b5664a 355 if (TCPH_FLAGS(th) & TCP_PSH) {
AndyA 22:0dd9c1b5664a 356 changes |= TCP_PUSH_BIT;
AndyA 22:0dd9c1b5664a 357 }
AndyA 22:0dd9c1b5664a 358 /*
AndyA 22:0dd9c1b5664a 359 * Grab the cksum before we overwrite it below. Then update our
AndyA 22:0dd9c1b5664a 360 * state with this packet's header.
AndyA 22:0dd9c1b5664a 361 */
AndyA 22:0dd9c1b5664a 362 deltaA = ntohs(th->chksum);
AndyA 22:0dd9c1b5664a 363 BCOPY(ip, &cs->cs_ip, hlen);
AndyA 22:0dd9c1b5664a 364
AndyA 22:0dd9c1b5664a 365 /*
AndyA 22:0dd9c1b5664a 366 * We want to use the original packet as our compressed packet.
AndyA 22:0dd9c1b5664a 367 * (cp - new_seq) is the number of bytes we need for compressed
AndyA 22:0dd9c1b5664a 368 * sequence numbers. In addition we need one byte for the change
AndyA 22:0dd9c1b5664a 369 * mask, one for the connection id and two for the tcp checksum.
AndyA 22:0dd9c1b5664a 370 * So, (cp - new_seq) + 4 bytes of header are needed. hlen is how
AndyA 22:0dd9c1b5664a 371 * many bytes of the original packet to toss so subtract the two to
AndyA 22:0dd9c1b5664a 372 * get the new packet size.
AndyA 22:0dd9c1b5664a 373 */
AndyA 22:0dd9c1b5664a 374 deltaS = (u_short)(cp - new_seq);
AndyA 22:0dd9c1b5664a 375 if (!comp->compressSlot || comp->last_xmit != cs->cs_id) {
AndyA 22:0dd9c1b5664a 376 comp->last_xmit = cs->cs_id;
AndyA 22:0dd9c1b5664a 377 hlen -= deltaS + 4;
AndyA 22:0dd9c1b5664a 378 if(pbuf_header(pb, -hlen)){
AndyA 22:0dd9c1b5664a 379 /* Can we cope with this failing? Just assert for now */
AndyA 22:0dd9c1b5664a 380 LWIP_ASSERT("pbuf_header failed\n", 0);
AndyA 22:0dd9c1b5664a 381 }
AndyA 22:0dd9c1b5664a 382 cp = (u_char *)pb->payload;
AndyA 22:0dd9c1b5664a 383 *cp++ = (u_char)(changes | NEW_C);
AndyA 22:0dd9c1b5664a 384 *cp++ = cs->cs_id;
AndyA 22:0dd9c1b5664a 385 } else {
AndyA 22:0dd9c1b5664a 386 hlen -= deltaS + 3;
AndyA 22:0dd9c1b5664a 387 if(pbuf_header(pb, -hlen)) {
AndyA 22:0dd9c1b5664a 388 /* Can we cope with this failing? Just assert for now */
AndyA 22:0dd9c1b5664a 389 LWIP_ASSERT("pbuf_header failed\n", 0);
AndyA 22:0dd9c1b5664a 390 }
AndyA 22:0dd9c1b5664a 391 cp = (u_char *)pb->payload;
AndyA 22:0dd9c1b5664a 392 *cp++ = (u_char)changes;
AndyA 22:0dd9c1b5664a 393 }
AndyA 22:0dd9c1b5664a 394 *cp++ = (u_char)(deltaA >> 8);
AndyA 22:0dd9c1b5664a 395 *cp++ = (u_char)deltaA;
AndyA 22:0dd9c1b5664a 396 BCOPY(new_seq, cp, deltaS);
AndyA 22:0dd9c1b5664a 397 INCR(vjs_compressed);
AndyA 22:0dd9c1b5664a 398 return (TYPE_COMPRESSED_TCP);
AndyA 22:0dd9c1b5664a 399
AndyA 22:0dd9c1b5664a 400 /*
AndyA 22:0dd9c1b5664a 401 * Update connection state cs & send uncompressed packet (that is,
AndyA 22:0dd9c1b5664a 402 * a regular ip/tcp packet but with the 'conversation id' we hope
AndyA 22:0dd9c1b5664a 403 * to use on future compressed packets in the protocol field).
AndyA 22:0dd9c1b5664a 404 */
AndyA 22:0dd9c1b5664a 405 uncompressed:
AndyA 22:0dd9c1b5664a 406 BCOPY(ip, &cs->cs_ip, hlen);
AndyA 22:0dd9c1b5664a 407 IPH_PROTO_SET(ip, cs->cs_id);
AndyA 22:0dd9c1b5664a 408 comp->last_xmit = cs->cs_id;
AndyA 22:0dd9c1b5664a 409 return (TYPE_UNCOMPRESSED_TCP);
AndyA 22:0dd9c1b5664a 410 }
AndyA 22:0dd9c1b5664a 411
AndyA 22:0dd9c1b5664a 412 /*
AndyA 22:0dd9c1b5664a 413 * Called when we may have missed a packet.
AndyA 22:0dd9c1b5664a 414 */
AndyA 22:0dd9c1b5664a 415 void
AndyA 22:0dd9c1b5664a 416 vj_uncompress_err(struct vjcompress *comp)
AndyA 22:0dd9c1b5664a 417 {
AndyA 22:0dd9c1b5664a 418 comp->flags |= VJF_TOSS;
AndyA 22:0dd9c1b5664a 419 INCR(vjs_errorin);
AndyA 22:0dd9c1b5664a 420 }
AndyA 22:0dd9c1b5664a 421
AndyA 22:0dd9c1b5664a 422 /*
AndyA 22:0dd9c1b5664a 423 * "Uncompress" a packet of type TYPE_UNCOMPRESSED_TCP.
AndyA 22:0dd9c1b5664a 424 * Return 0 on success, -1 on failure.
AndyA 22:0dd9c1b5664a 425 */
AndyA 22:0dd9c1b5664a 426 int
AndyA 22:0dd9c1b5664a 427 vj_uncompress_uncomp(struct pbuf *nb, struct vjcompress *comp)
AndyA 22:0dd9c1b5664a 428 {
AndyA 22:0dd9c1b5664a 429 register u_int hlen;
AndyA 22:0dd9c1b5664a 430 register struct cstate *cs;
AndyA 22:0dd9c1b5664a 431 register struct ip_hdr *ip;
AndyA 22:0dd9c1b5664a 432
AndyA 22:0dd9c1b5664a 433 ip = (struct ip_hdr *)nb->payload;
AndyA 22:0dd9c1b5664a 434 hlen = IPH_HL(ip) << 2;
AndyA 22:0dd9c1b5664a 435 if (IPH_PROTO(ip) >= MAX_SLOTS
AndyA 22:0dd9c1b5664a 436 || hlen + sizeof(struct tcp_hdr) > nb->len
AndyA 22:0dd9c1b5664a 437 || (hlen += TCPH_OFFSET(((struct tcp_hdr *)&((char *)ip)[hlen])) << 2)
AndyA 22:0dd9c1b5664a 438 > nb->len
AndyA 22:0dd9c1b5664a 439 || hlen > MAX_HDR) {
AndyA 22:0dd9c1b5664a 440 PPPDEBUG(LOG_INFO, ("vj_uncompress_uncomp: bad cid=%d, hlen=%d buflen=%d\n",
AndyA 22:0dd9c1b5664a 441 IPH_PROTO(ip), hlen, nb->len));
AndyA 22:0dd9c1b5664a 442 comp->flags |= VJF_TOSS;
AndyA 22:0dd9c1b5664a 443 INCR(vjs_errorin);
AndyA 22:0dd9c1b5664a 444 return -1;
AndyA 22:0dd9c1b5664a 445 }
AndyA 22:0dd9c1b5664a 446 cs = &comp->rstate[comp->last_recv = IPH_PROTO(ip)];
AndyA 22:0dd9c1b5664a 447 comp->flags &=~ VJF_TOSS;
AndyA 22:0dd9c1b5664a 448 IPH_PROTO_SET(ip, IP_PROTO_TCP);
AndyA 22:0dd9c1b5664a 449 BCOPY(ip, &cs->cs_ip, hlen);
AndyA 22:0dd9c1b5664a 450 cs->cs_hlen = (u_short)hlen;
AndyA 22:0dd9c1b5664a 451 INCR(vjs_uncompressedin);
AndyA 22:0dd9c1b5664a 452 return 0;
AndyA 22:0dd9c1b5664a 453 }
AndyA 22:0dd9c1b5664a 454
AndyA 22:0dd9c1b5664a 455 /*
AndyA 22:0dd9c1b5664a 456 * Uncompress a packet of type TYPE_COMPRESSED_TCP.
AndyA 22:0dd9c1b5664a 457 * The packet is composed of a buffer chain and the first buffer
AndyA 22:0dd9c1b5664a 458 * must contain an accurate chain length.
AndyA 22:0dd9c1b5664a 459 * The first buffer must include the entire compressed TCP/IP header.
AndyA 22:0dd9c1b5664a 460 * This procedure replaces the compressed header with the uncompressed
AndyA 22:0dd9c1b5664a 461 * header and returns the length of the VJ header.
AndyA 22:0dd9c1b5664a 462 */
AndyA 22:0dd9c1b5664a 463 int
AndyA 22:0dd9c1b5664a 464 vj_uncompress_tcp(struct pbuf **nb, struct vjcompress *comp)
AndyA 22:0dd9c1b5664a 465 {
AndyA 22:0dd9c1b5664a 466 u_char *cp;
AndyA 22:0dd9c1b5664a 467 struct tcp_hdr *th;
AndyA 22:0dd9c1b5664a 468 struct cstate *cs;
AndyA 22:0dd9c1b5664a 469 u_short *bp;
AndyA 22:0dd9c1b5664a 470 struct pbuf *n0 = *nb;
AndyA 22:0dd9c1b5664a 471 u32_t tmp;
AndyA 22:0dd9c1b5664a 472 u_int vjlen, hlen, changes;
AndyA 22:0dd9c1b5664a 473
AndyA 22:0dd9c1b5664a 474 INCR(vjs_compressedin);
AndyA 22:0dd9c1b5664a 475 cp = (u_char *)n0->payload;
AndyA 22:0dd9c1b5664a 476 changes = *cp++;
AndyA 22:0dd9c1b5664a 477 if (changes & NEW_C) {
AndyA 22:0dd9c1b5664a 478 /*
AndyA 22:0dd9c1b5664a 479 * Make sure the state index is in range, then grab the state.
AndyA 22:0dd9c1b5664a 480 * If we have a good state index, clear the 'discard' flag.
AndyA 22:0dd9c1b5664a 481 */
AndyA 22:0dd9c1b5664a 482 if (*cp >= MAX_SLOTS) {
AndyA 22:0dd9c1b5664a 483 PPPDEBUG(LOG_INFO, ("vj_uncompress_tcp: bad cid=%d\n", *cp));
AndyA 22:0dd9c1b5664a 484 goto bad;
AndyA 22:0dd9c1b5664a 485 }
AndyA 22:0dd9c1b5664a 486
AndyA 22:0dd9c1b5664a 487 comp->flags &=~ VJF_TOSS;
AndyA 22:0dd9c1b5664a 488 comp->last_recv = *cp++;
AndyA 22:0dd9c1b5664a 489 } else {
AndyA 22:0dd9c1b5664a 490 /*
AndyA 22:0dd9c1b5664a 491 * this packet has an implicit state index. If we've
AndyA 22:0dd9c1b5664a 492 * had a line error since the last time we got an
AndyA 22:0dd9c1b5664a 493 * explicit state index, we have to toss the packet.
AndyA 22:0dd9c1b5664a 494 */
AndyA 22:0dd9c1b5664a 495 if (comp->flags & VJF_TOSS) {
AndyA 22:0dd9c1b5664a 496 PPPDEBUG(LOG_INFO, ("vj_uncompress_tcp: tossing\n"));
AndyA 22:0dd9c1b5664a 497 INCR(vjs_tossed);
AndyA 22:0dd9c1b5664a 498 return (-1);
AndyA 22:0dd9c1b5664a 499 }
AndyA 22:0dd9c1b5664a 500 }
AndyA 22:0dd9c1b5664a 501 cs = &comp->rstate[comp->last_recv];
AndyA 22:0dd9c1b5664a 502 hlen = IPH_HL(&cs->cs_ip) << 2;
AndyA 22:0dd9c1b5664a 503 th = (struct tcp_hdr *)&((u_char *)&cs->cs_ip)[hlen];
AndyA 22:0dd9c1b5664a 504 th->chksum = htons((*cp << 8) | cp[1]);
AndyA 22:0dd9c1b5664a 505 cp += 2;
AndyA 22:0dd9c1b5664a 506 if (changes & TCP_PUSH_BIT) {
AndyA 22:0dd9c1b5664a 507 TCPH_SET_FLAG(th, TCP_PSH);
AndyA 22:0dd9c1b5664a 508 } else {
AndyA 22:0dd9c1b5664a 509 TCPH_UNSET_FLAG(th, TCP_PSH);
AndyA 22:0dd9c1b5664a 510 }
AndyA 22:0dd9c1b5664a 511
AndyA 22:0dd9c1b5664a 512 switch (changes & SPECIALS_MASK) {
AndyA 22:0dd9c1b5664a 513 case SPECIAL_I:
AndyA 22:0dd9c1b5664a 514 {
AndyA 22:0dd9c1b5664a 515 register u32_t i = ntohs(IPH_LEN(&cs->cs_ip)) - cs->cs_hlen;
AndyA 22:0dd9c1b5664a 516 /* some compilers can't nest inline assembler.. */
AndyA 22:0dd9c1b5664a 517 tmp = ntohl(th->ackno) + i;
AndyA 22:0dd9c1b5664a 518 th->ackno = htonl(tmp);
AndyA 22:0dd9c1b5664a 519 tmp = ntohl(th->seqno) + i;
AndyA 22:0dd9c1b5664a 520 th->seqno = htonl(tmp);
AndyA 22:0dd9c1b5664a 521 }
AndyA 22:0dd9c1b5664a 522 break;
AndyA 22:0dd9c1b5664a 523
AndyA 22:0dd9c1b5664a 524 case SPECIAL_D:
AndyA 22:0dd9c1b5664a 525 /* some compilers can't nest inline assembler.. */
AndyA 22:0dd9c1b5664a 526 tmp = ntohl(th->seqno) + ntohs(IPH_LEN(&cs->cs_ip)) - cs->cs_hlen;
AndyA 22:0dd9c1b5664a 527 th->seqno = htonl(tmp);
AndyA 22:0dd9c1b5664a 528 break;
AndyA 22:0dd9c1b5664a 529
AndyA 22:0dd9c1b5664a 530 default:
AndyA 22:0dd9c1b5664a 531 if (changes & NEW_U) {
AndyA 22:0dd9c1b5664a 532 TCPH_SET_FLAG(th, TCP_URG);
AndyA 22:0dd9c1b5664a 533 DECODEU(th->urgp);
AndyA 22:0dd9c1b5664a 534 } else {
AndyA 22:0dd9c1b5664a 535 TCPH_UNSET_FLAG(th, TCP_URG);
AndyA 22:0dd9c1b5664a 536 }
AndyA 22:0dd9c1b5664a 537 if (changes & NEW_W) {
AndyA 22:0dd9c1b5664a 538 DECODES(th->wnd);
AndyA 22:0dd9c1b5664a 539 }
AndyA 22:0dd9c1b5664a 540 if (changes & NEW_A) {
AndyA 22:0dd9c1b5664a 541 DECODEL(th->ackno);
AndyA 22:0dd9c1b5664a 542 }
AndyA 22:0dd9c1b5664a 543 if (changes & NEW_S) {
AndyA 22:0dd9c1b5664a 544 DECODEL(th->seqno);
AndyA 22:0dd9c1b5664a 545 }
AndyA 22:0dd9c1b5664a 546 break;
AndyA 22:0dd9c1b5664a 547 }
AndyA 22:0dd9c1b5664a 548 if (changes & NEW_I) {
AndyA 22:0dd9c1b5664a 549 DECODES(cs->cs_ip._id);
AndyA 22:0dd9c1b5664a 550 } else {
AndyA 22:0dd9c1b5664a 551 IPH_ID_SET(&cs->cs_ip, ntohs(IPH_ID(&cs->cs_ip)) + 1);
AndyA 22:0dd9c1b5664a 552 IPH_ID_SET(&cs->cs_ip, htons(IPH_ID(&cs->cs_ip)));
AndyA 22:0dd9c1b5664a 553 }
AndyA 22:0dd9c1b5664a 554
AndyA 22:0dd9c1b5664a 555 /*
AndyA 22:0dd9c1b5664a 556 * At this point, cp points to the first byte of data in the
AndyA 22:0dd9c1b5664a 557 * packet. Fill in the IP total length and update the IP
AndyA 22:0dd9c1b5664a 558 * header checksum.
AndyA 22:0dd9c1b5664a 559 */
AndyA 22:0dd9c1b5664a 560 vjlen = (u_short)(cp - (u_char*)n0->payload);
AndyA 22:0dd9c1b5664a 561 if (n0->len < vjlen) {
AndyA 22:0dd9c1b5664a 562 /*
AndyA 22:0dd9c1b5664a 563 * We must have dropped some characters (crc should detect
AndyA 22:0dd9c1b5664a 564 * this but the old slip framing won't)
AndyA 22:0dd9c1b5664a 565 */
AndyA 22:0dd9c1b5664a 566 PPPDEBUG(LOG_INFO, ("vj_uncompress_tcp: head buffer %d too short %d\n",
AndyA 22:0dd9c1b5664a 567 n0->len, vjlen));
AndyA 22:0dd9c1b5664a 568 goto bad;
AndyA 22:0dd9c1b5664a 569 }
AndyA 22:0dd9c1b5664a 570
AndyA 22:0dd9c1b5664a 571 #if BYTE_ORDER == LITTLE_ENDIAN
AndyA 22:0dd9c1b5664a 572 tmp = n0->tot_len - vjlen + cs->cs_hlen;
AndyA 22:0dd9c1b5664a 573 IPH_LEN_SET(&cs->cs_ip, htons((u_short)tmp));
AndyA 22:0dd9c1b5664a 574 #else
AndyA 22:0dd9c1b5664a 575 IPH_LEN_SET(&cs->cs_ip, htons(n0->tot_len - vjlen + cs->cs_hlen));
AndyA 22:0dd9c1b5664a 576 #endif
AndyA 22:0dd9c1b5664a 577
AndyA 22:0dd9c1b5664a 578 /* recompute the ip header checksum */
AndyA 22:0dd9c1b5664a 579 bp = (u_short *) &cs->cs_ip;
AndyA 22:0dd9c1b5664a 580 IPH_CHKSUM_SET(&cs->cs_ip, 0);
AndyA 22:0dd9c1b5664a 581 for (tmp = 0; hlen > 0; hlen -= 2) {
AndyA 22:0dd9c1b5664a 582 tmp += *bp++;
AndyA 22:0dd9c1b5664a 583 }
AndyA 22:0dd9c1b5664a 584 tmp = (tmp & 0xffff) + (tmp >> 16);
AndyA 22:0dd9c1b5664a 585 tmp = (tmp & 0xffff) + (tmp >> 16);
AndyA 22:0dd9c1b5664a 586 IPH_CHKSUM_SET(&cs->cs_ip, (u_short)(~tmp));
AndyA 22:0dd9c1b5664a 587
AndyA 22:0dd9c1b5664a 588 /* Remove the compressed header and prepend the uncompressed header. */
AndyA 22:0dd9c1b5664a 589 if(pbuf_header(n0, -((s16_t)(vjlen)))) {
AndyA 22:0dd9c1b5664a 590 /* Can we cope with this failing? Just assert for now */
AndyA 22:0dd9c1b5664a 591 LWIP_ASSERT("pbuf_header failed\n", 0);
AndyA 22:0dd9c1b5664a 592 goto bad;
AndyA 22:0dd9c1b5664a 593 }
AndyA 22:0dd9c1b5664a 594
AndyA 22:0dd9c1b5664a 595 if(LWIP_MEM_ALIGN(n0->payload) != n0->payload) {
AndyA 22:0dd9c1b5664a 596 struct pbuf *np, *q;
AndyA 22:0dd9c1b5664a 597 u8_t *bufptr;
AndyA 22:0dd9c1b5664a 598
AndyA 22:0dd9c1b5664a 599 np = pbuf_alloc(PBUF_RAW, n0->len + cs->cs_hlen, PBUF_POOL);
AndyA 22:0dd9c1b5664a 600 if(!np) {
AndyA 22:0dd9c1b5664a 601 PPPDEBUG(LOG_WARNING, ("vj_uncompress_tcp: realign failed\n"));
AndyA 22:0dd9c1b5664a 602 goto bad;
AndyA 22:0dd9c1b5664a 603 }
AndyA 22:0dd9c1b5664a 604
AndyA 22:0dd9c1b5664a 605 if(pbuf_header(np, -cs->cs_hlen)) {
AndyA 22:0dd9c1b5664a 606 /* Can we cope with this failing? Just assert for now */
AndyA 22:0dd9c1b5664a 607 LWIP_ASSERT("pbuf_header failed\n", 0);
AndyA 22:0dd9c1b5664a 608 goto bad;
AndyA 22:0dd9c1b5664a 609 }
AndyA 22:0dd9c1b5664a 610
AndyA 22:0dd9c1b5664a 611 bufptr = n0->payload;
AndyA 22:0dd9c1b5664a 612 for(q = np; q != NULL; q = q->next) {
AndyA 22:0dd9c1b5664a 613 MEMCPY(q->payload, bufptr, q->len);
AndyA 22:0dd9c1b5664a 614 bufptr += q->len;
AndyA 22:0dd9c1b5664a 615 }
AndyA 22:0dd9c1b5664a 616
AndyA 22:0dd9c1b5664a 617 if(n0->next) {
AndyA 22:0dd9c1b5664a 618 pbuf_chain(np, n0->next);
AndyA 22:0dd9c1b5664a 619 pbuf_dechain(n0);
AndyA 22:0dd9c1b5664a 620 }
AndyA 22:0dd9c1b5664a 621 pbuf_free(n0);
AndyA 22:0dd9c1b5664a 622 n0 = np;
AndyA 22:0dd9c1b5664a 623 }
AndyA 22:0dd9c1b5664a 624
AndyA 22:0dd9c1b5664a 625 if(pbuf_header(n0, cs->cs_hlen)) {
AndyA 22:0dd9c1b5664a 626 struct pbuf *np;
AndyA 22:0dd9c1b5664a 627
AndyA 22:0dd9c1b5664a 628 LWIP_ASSERT("vj_uncompress_tcp: cs->cs_hlen <= PBUF_POOL_BUFSIZE", cs->cs_hlen <= PBUF_POOL_BUFSIZE);
AndyA 22:0dd9c1b5664a 629 np = pbuf_alloc(PBUF_RAW, cs->cs_hlen, PBUF_POOL);
AndyA 22:0dd9c1b5664a 630 if(!np) {
AndyA 22:0dd9c1b5664a 631 PPPDEBUG(LOG_WARNING, ("vj_uncompress_tcp: prepend failed\n"));
AndyA 22:0dd9c1b5664a 632 goto bad;
AndyA 22:0dd9c1b5664a 633 }
AndyA 22:0dd9c1b5664a 634 pbuf_cat(np, n0);
AndyA 22:0dd9c1b5664a 635 n0 = np;
AndyA 22:0dd9c1b5664a 636 }
AndyA 22:0dd9c1b5664a 637 LWIP_ASSERT("n0->len >= cs->cs_hlen", n0->len >= cs->cs_hlen);
AndyA 22:0dd9c1b5664a 638 MEMCPY(n0->payload, &cs->cs_ip, cs->cs_hlen);
AndyA 22:0dd9c1b5664a 639
AndyA 22:0dd9c1b5664a 640 *nb = n0;
AndyA 22:0dd9c1b5664a 641
AndyA 22:0dd9c1b5664a 642 return vjlen;
AndyA 22:0dd9c1b5664a 643
AndyA 22:0dd9c1b5664a 644 bad:
AndyA 22:0dd9c1b5664a 645 comp->flags |= VJF_TOSS;
AndyA 22:0dd9c1b5664a 646 INCR(vjs_errorin);
AndyA 22:0dd9c1b5664a 647 return (-1);
AndyA 22:0dd9c1b5664a 648 }
AndyA 22:0dd9c1b5664a 649
AndyA 22:0dd9c1b5664a 650 #endif /* VJ_SUPPORT */
AndyA 22:0dd9c1b5664a 651
AndyA 22:0dd9c1b5664a 652 #endif /* PPP_SUPPORT */