Yann Garcia / Mbed 2 deprecated DS130x_I2CApp

This short program illustrates how to use the DS130x_I2C library. My objective is to share the same RTC with Microchip 18F MCU.

Dependencies:   mbed DebugLibrary

NetServices/lwip/netif/ppp/vj.c@0:f30e2135b0db, 2011-02-09 (annotated)

Committer:
Yann
Date:
Wed Feb 09 13:57:49 2011 +0000
Revision:
0:f30e2135b0db
V0.0.0.1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Yann 0:f30e2135b0db 1 /*
Yann 0:f30e2135b0db 2 * Routines to compress and uncompess tcp packets (for transmission
Yann 0:f30e2135b0db 3 * over low speed serial lines.
Yann 0:f30e2135b0db 4 *
Yann 0:f30e2135b0db 5 * Copyright (c) 1989 Regents of the University of California.
Yann 0:f30e2135b0db 6 * All rights reserved.
Yann 0:f30e2135b0db 7 *
Yann 0:f30e2135b0db 8 * Redistribution and use in source and binary forms are permitted
Yann 0:f30e2135b0db 9 * provided that the above copyright notice and this paragraph are
Yann 0:f30e2135b0db 10 * duplicated in all such forms and that any documentation,
Yann 0:f30e2135b0db 11 * advertising materials, and other materials related to such
Yann 0:f30e2135b0db 12 * distribution and use acknowledge that the software was developed
Yann 0:f30e2135b0db 13 * by the University of California, Berkeley. The name of the
Yann 0:f30e2135b0db 14 * University may not be used to endorse or promote products derived
Yann 0:f30e2135b0db 15 * from this software without specific prior written permission.
Yann 0:f30e2135b0db 16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
Yann 0:f30e2135b0db 17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
Yann 0:f30e2135b0db 18 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
Yann 0:f30e2135b0db 19 *
Yann 0:f30e2135b0db 20 * Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989:
Yann 0:f30e2135b0db 21 * Initial distribution.
Yann 0:f30e2135b0db 22 *
Yann 0:f30e2135b0db 23 * Modified June 1993 by Paul Mackerras, paulus@cs.anu.edu.au,
Yann 0:f30e2135b0db 24 * so that the entire packet being decompressed doesn't have
Yann 0:f30e2135b0db 25 * to be in contiguous memory (just the compressed header).
Yann 0:f30e2135b0db 26 *
Yann 0:f30e2135b0db 27 * Modified March 1998 by Guy Lancaster, glanca@gesn.com,
Yann 0:f30e2135b0db 28 * for a 16 bit processor.
Yann 0:f30e2135b0db 29 */
Yann 0:f30e2135b0db 30
Yann 0:f30e2135b0db 31 #include "lwip/opt.h"
Yann 0:f30e2135b0db 32
Yann 0:f30e2135b0db 33 #if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
Yann 0:f30e2135b0db 34
Yann 0:f30e2135b0db 35 #include "ppp.h"
Yann 0:f30e2135b0db 36 #include "pppdebug.h"
Yann 0:f30e2135b0db 37
Yann 0:f30e2135b0db 38 #include "vj.h"
Yann 0:f30e2135b0db 39
Yann 0:f30e2135b0db 40 #include <string.h>
Yann 0:f30e2135b0db 41
Yann 0:f30e2135b0db 42 #if VJ_SUPPORT
Yann 0:f30e2135b0db 43
Yann 0:f30e2135b0db 44 #if LINK_STATS
Yann 0:f30e2135b0db 45 #define INCR(counter) ++comp->stats.counter
Yann 0:f30e2135b0db 46 #else
Yann 0:f30e2135b0db 47 #define INCR(counter)
Yann 0:f30e2135b0db 48 #endif
Yann 0:f30e2135b0db 49
Yann 0:f30e2135b0db 50 void
Yann 0:f30e2135b0db 51 vj_compress_init(struct vjcompress *comp)
Yann 0:f30e2135b0db 52 {
Yann 0:f30e2135b0db 53 register u_char i;
Yann 0:f30e2135b0db 54 register struct cstate *tstate = comp->tstate;
Yann 0:f30e2135b0db 55
Yann 0:f30e2135b0db 56 #if MAX_SLOTS == 0
Yann 0:f30e2135b0db 57 memset((char *)comp, 0, sizeof(*comp));
Yann 0:f30e2135b0db 58 #endif
Yann 0:f30e2135b0db 59 comp->maxSlotIndex = MAX_SLOTS - 1;
Yann 0:f30e2135b0db 60 comp->compressSlot = 0; /* Disable slot ID compression by default. */
Yann 0:f30e2135b0db 61 for (i = MAX_SLOTS - 1; i > 0; --i) {
Yann 0:f30e2135b0db 62 tstate[i].cs_id = i;
Yann 0:f30e2135b0db 63 tstate[i].cs_next = &tstate[i - 1];
Yann 0:f30e2135b0db 64 }
Yann 0:f30e2135b0db 65 tstate[0].cs_next = &tstate[MAX_SLOTS - 1];
Yann 0:f30e2135b0db 66 tstate[0].cs_id = 0;
Yann 0:f30e2135b0db 67 comp->last_cs = &tstate[0];
Yann 0:f30e2135b0db 68 comp->last_recv = 255;
Yann 0:f30e2135b0db 69 comp->last_xmit = 255;
Yann 0:f30e2135b0db 70 comp->flags = VJF_TOSS;
Yann 0:f30e2135b0db 71 }
Yann 0:f30e2135b0db 72
Yann 0:f30e2135b0db 73
Yann 0:f30e2135b0db 74 /* ENCODE encodes a number that is known to be non-zero. ENCODEZ
Yann 0:f30e2135b0db 75 * checks for zero (since zero has to be encoded in the long, 3 byte
Yann 0:f30e2135b0db 76 * form).
Yann 0:f30e2135b0db 77 */
Yann 0:f30e2135b0db 78 #define ENCODE(n) { \
Yann 0:f30e2135b0db 79 if ((u_short)(n) >= 256) { \
Yann 0:f30e2135b0db 80 *cp++ = 0; \
Yann 0:f30e2135b0db 81 cp[1] = (u_char)(n); \
Yann 0:f30e2135b0db 82 cp[0] = (u_char)((n) >> 8); \
Yann 0:f30e2135b0db 83 cp += 2; \
Yann 0:f30e2135b0db 84 } else { \
Yann 0:f30e2135b0db 85 *cp++ = (u_char)(n); \
Yann 0:f30e2135b0db 86 } \
Yann 0:f30e2135b0db 87 }
Yann 0:f30e2135b0db 88 #define ENCODEZ(n) { \
Yann 0:f30e2135b0db 89 if ((u_short)(n) >= 256 || (u_short)(n) == 0) { \
Yann 0:f30e2135b0db 90 *cp++ = 0; \
Yann 0:f30e2135b0db 91 cp[1] = (u_char)(n); \
Yann 0:f30e2135b0db 92 cp[0] = (u_char)((n) >> 8); \
Yann 0:f30e2135b0db 93 cp += 2; \
Yann 0:f30e2135b0db 94 } else { \
Yann 0:f30e2135b0db 95 *cp++ = (u_char)(n); \
Yann 0:f30e2135b0db 96 } \
Yann 0:f30e2135b0db 97 }
Yann 0:f30e2135b0db 98
Yann 0:f30e2135b0db 99 #define DECODEL(f) { \
Yann 0:f30e2135b0db 100 if (*cp == 0) {\
Yann 0:f30e2135b0db 101 u32_t tmp = ntohl(f) + ((cp[1] << 8) | cp[2]); \
Yann 0:f30e2135b0db 102 (f) = htonl(tmp); \
Yann 0:f30e2135b0db 103 cp += 3; \
Yann 0:f30e2135b0db 104 } else { \
Yann 0:f30e2135b0db 105 u32_t tmp = ntohl(f) + (u32_t)*cp++; \
Yann 0:f30e2135b0db 106 (f) = htonl(tmp); \
Yann 0:f30e2135b0db 107 } \
Yann 0:f30e2135b0db 108 }
Yann 0:f30e2135b0db 109
Yann 0:f30e2135b0db 110 #define DECODES(f) { \
Yann 0:f30e2135b0db 111 if (*cp == 0) {\
Yann 0:f30e2135b0db 112 u_short tmp = ntohs(f) + (((u_short)cp[1] << 8) | cp[2]); \
Yann 0:f30e2135b0db 113 (f) = htons(tmp); \
Yann 0:f30e2135b0db 114 cp += 3; \
Yann 0:f30e2135b0db 115 } else { \
Yann 0:f30e2135b0db 116 u_short tmp = ntohs(f) + (u_short)*cp++; \
Yann 0:f30e2135b0db 117 (f) = htons(tmp); \
Yann 0:f30e2135b0db 118 } \
Yann 0:f30e2135b0db 119 }
Yann 0:f30e2135b0db 120
Yann 0:f30e2135b0db 121 #define DECODEU(f) { \
Yann 0:f30e2135b0db 122 if (*cp == 0) {\
Yann 0:f30e2135b0db 123 (f) = htons(((u_short)cp[1] << 8) | cp[2]); \
Yann 0:f30e2135b0db 124 cp += 3; \
Yann 0:f30e2135b0db 125 } else { \
Yann 0:f30e2135b0db 126 (f) = htons((u_short)*cp++); \
Yann 0:f30e2135b0db 127 } \
Yann 0:f30e2135b0db 128 }
Yann 0:f30e2135b0db 129
Yann 0:f30e2135b0db 130 /*
Yann 0:f30e2135b0db 131 * vj_compress_tcp - Attempt to do Van Jacobson header compression on a
Yann 0:f30e2135b0db 132 * packet. This assumes that nb and comp are not null and that the first
Yann 0:f30e2135b0db 133 * buffer of the chain contains a valid IP header.
Yann 0:f30e2135b0db 134 * Return the VJ type code indicating whether or not the packet was
Yann 0:f30e2135b0db 135 * compressed.
Yann 0:f30e2135b0db 136 */
Yann 0:f30e2135b0db 137 u_int
Yann 0:f30e2135b0db 138 vj_compress_tcp(struct vjcompress *comp, struct pbuf *pb)
Yann 0:f30e2135b0db 139 {
Yann 0:f30e2135b0db 140 register struct ip_hdr *ip = (struct ip_hdr *)pb->payload;
Yann 0:f30e2135b0db 141 register struct cstate *cs = comp->last_cs->cs_next;
Yann 0:f30e2135b0db 142 register u_short hlen = IPH_HL(ip);
Yann 0:f30e2135b0db 143 register struct tcp_hdr *oth;
Yann 0:f30e2135b0db 144 register struct tcp_hdr *th;
Yann 0:f30e2135b0db 145 register u_short deltaS, deltaA;
Yann 0:f30e2135b0db 146 register u_long deltaL;
Yann 0:f30e2135b0db 147 register u_int changes = 0;
Yann 0:f30e2135b0db 148 u_char new_seq[16];
Yann 0:f30e2135b0db 149 register u_char *cp = new_seq;
Yann 0:f30e2135b0db 150
Yann 0:f30e2135b0db 151 /*
Yann 0:f30e2135b0db 152 * Check that the packet is IP proto TCP.
Yann 0:f30e2135b0db 153 */
Yann 0:f30e2135b0db 154 if (IPH_PROTO(ip) != IP_PROTO_TCP) {
Yann 0:f30e2135b0db 155 return (TYPE_IP);
Yann 0:f30e2135b0db 156 }
Yann 0:f30e2135b0db 157
Yann 0:f30e2135b0db 158 /*
Yann 0:f30e2135b0db 159 * Bail if this is an IP fragment or if the TCP packet isn't
Yann 0:f30e2135b0db 160 * `compressible' (i.e., ACK isn't set or some other control bit is
Yann 0:f30e2135b0db 161 * set).
Yann 0:f30e2135b0db 162 */
Yann 0:f30e2135b0db 163 if ((IPH_OFFSET(ip) & PP_HTONS(0x3fff)) || pb->tot_len < 40) {
Yann 0:f30e2135b0db 164 return (TYPE_IP);
Yann 0:f30e2135b0db 165 }
Yann 0:f30e2135b0db 166 th = (struct tcp_hdr *)&((long *)ip)[hlen];
Yann 0:f30e2135b0db 167 if ((TCPH_FLAGS(th) & (TCP_SYN|TCP_FIN|TCP_RST|TCP_ACK)) != TCP_ACK) {
Yann 0:f30e2135b0db 168 return (TYPE_IP);
Yann 0:f30e2135b0db 169 }
Yann 0:f30e2135b0db 170 /*
Yann 0:f30e2135b0db 171 * Packet is compressible -- we're going to send either a
Yann 0:f30e2135b0db 172 * COMPRESSED_TCP or UNCOMPRESSED_TCP packet. Either way we need
Yann 0:f30e2135b0db 173 * to locate (or create) the connection state. Special case the
Yann 0:f30e2135b0db 174 * most recently used connection since it's most likely to be used
Yann 0:f30e2135b0db 175 * again & we don't have to do any reordering if it's used.
Yann 0:f30e2135b0db 176 */
Yann 0:f30e2135b0db 177 INCR(vjs_packets);
Yann 0:f30e2135b0db 178 if (!ip_addr_cmp(&ip->src, &cs->cs_ip.src)
Yann 0:f30e2135b0db 179 || !ip_addr_cmp(&ip->dest, &cs->cs_ip.dest)
Yann 0:f30e2135b0db 180 || *(long *)th != ((long *)&cs->cs_ip)[IPH_HL(&cs->cs_ip)]) {
Yann 0:f30e2135b0db 181 /*
Yann 0:f30e2135b0db 182 * Wasn't the first -- search for it.
Yann 0:f30e2135b0db 183 *
Yann 0:f30e2135b0db 184 * States are kept in a circularly linked list with
Yann 0:f30e2135b0db 185 * last_cs pointing to the end of the list. The
Yann 0:f30e2135b0db 186 * list is kept in lru order by moving a state to the
Yann 0:f30e2135b0db 187 * head of the list whenever it is referenced. Since
Yann 0:f30e2135b0db 188 * the list is short and, empirically, the connection
Yann 0:f30e2135b0db 189 * we want is almost always near the front, we locate
Yann 0:f30e2135b0db 190 * states via linear search. If we don't find a state
Yann 0:f30e2135b0db 191 * for the datagram, the oldest state is (re-)used.
Yann 0:f30e2135b0db 192 */
Yann 0:f30e2135b0db 193 register struct cstate *lcs;
Yann 0:f30e2135b0db 194 register struct cstate *lastcs = comp->last_cs;
Yann 0:f30e2135b0db 195
Yann 0:f30e2135b0db 196 do {
Yann 0:f30e2135b0db 197 lcs = cs; cs = cs->cs_next;
Yann 0:f30e2135b0db 198 INCR(vjs_searches);
Yann 0:f30e2135b0db 199 if (ip_addr_cmp(&ip->src, &cs->cs_ip.src)
Yann 0:f30e2135b0db 200 && ip_addr_cmp(&ip->dest, &cs->cs_ip.dest)
Yann 0:f30e2135b0db 201 && *(long *)th == ((long *)&cs->cs_ip)[IPH_HL(&cs->cs_ip)]) {
Yann 0:f30e2135b0db 202 goto found;
Yann 0:f30e2135b0db 203 }
Yann 0:f30e2135b0db 204 } while (cs != lastcs);
Yann 0:f30e2135b0db 205
Yann 0:f30e2135b0db 206 /*
Yann 0:f30e2135b0db 207 * Didn't find it -- re-use oldest cstate. Send an
Yann 0:f30e2135b0db 208 * uncompressed packet that tells the other side what
Yann 0:f30e2135b0db 209 * connection number we're using for this conversation.
Yann 0:f30e2135b0db 210 * Note that since the state list is circular, the oldest
Yann 0:f30e2135b0db 211 * state points to the newest and we only need to set
Yann 0:f30e2135b0db 212 * last_cs to update the lru linkage.
Yann 0:f30e2135b0db 213 */
Yann 0:f30e2135b0db 214 INCR(vjs_misses);
Yann 0:f30e2135b0db 215 comp->last_cs = lcs;
Yann 0:f30e2135b0db 216 hlen += TCPH_OFFSET(th);
Yann 0:f30e2135b0db 217 hlen <<= 2;
Yann 0:f30e2135b0db 218 /* Check that the IP/TCP headers are contained in the first buffer. */
Yann 0:f30e2135b0db 219 if (hlen > pb->len) {
Yann 0:f30e2135b0db 220 return (TYPE_IP);
Yann 0:f30e2135b0db 221 }
Yann 0:f30e2135b0db 222 goto uncompressed;
Yann 0:f30e2135b0db 223
Yann 0:f30e2135b0db 224 found:
Yann 0:f30e2135b0db 225 /*
Yann 0:f30e2135b0db 226 * Found it -- move to the front on the connection list.
Yann 0:f30e2135b0db 227 */
Yann 0:f30e2135b0db 228 if (cs == lastcs) {
Yann 0:f30e2135b0db 229 comp->last_cs = lcs;
Yann 0:f30e2135b0db 230 } else {
Yann 0:f30e2135b0db 231 lcs->cs_next = cs->cs_next;
Yann 0:f30e2135b0db 232 cs->cs_next = lastcs->cs_next;
Yann 0:f30e2135b0db 233 lastcs->cs_next = cs;
Yann 0:f30e2135b0db 234 }
Yann 0:f30e2135b0db 235 }
Yann 0:f30e2135b0db 236
Yann 0:f30e2135b0db 237 oth = (struct tcp_hdr *)&((long *)&cs->cs_ip)[hlen];
Yann 0:f30e2135b0db 238 deltaS = hlen;
Yann 0:f30e2135b0db 239 hlen += TCPH_OFFSET(th);
Yann 0:f30e2135b0db 240 hlen <<= 2;
Yann 0:f30e2135b0db 241 /* Check that the IP/TCP headers are contained in the first buffer. */
Yann 0:f30e2135b0db 242 if (hlen > pb->len) {
Yann 0:f30e2135b0db 243 PPPDEBUG(LOG_INFO, ("vj_compress_tcp: header len %d spans buffers\n", hlen));
Yann 0:f30e2135b0db 244 return (TYPE_IP);
Yann 0:f30e2135b0db 245 }
Yann 0:f30e2135b0db 246
Yann 0:f30e2135b0db 247 /*
Yann 0:f30e2135b0db 248 * Make sure that only what we expect to change changed. The first
Yann 0:f30e2135b0db 249 * line of the `if' checks the IP protocol version, header length &
Yann 0:f30e2135b0db 250 * type of service. The 2nd line checks the "Don't fragment" bit.
Yann 0:f30e2135b0db 251 * The 3rd line checks the time-to-live and protocol (the protocol
Yann 0:f30e2135b0db 252 * check is unnecessary but costless). The 4th line checks the TCP
Yann 0:f30e2135b0db 253 * header length. The 5th line checks IP options, if any. The 6th
Yann 0:f30e2135b0db 254 * line checks TCP options, if any. If any of these things are
Yann 0:f30e2135b0db 255 * different between the previous & current datagram, we send the
Yann 0:f30e2135b0db 256 * current datagram `uncompressed'.
Yann 0:f30e2135b0db 257 */
Yann 0:f30e2135b0db 258 if (((u_short *)ip)[0] != ((u_short *)&cs->cs_ip)[0]
Yann 0:f30e2135b0db 259 || ((u_short *)ip)[3] != ((u_short *)&cs->cs_ip)[3]
Yann 0:f30e2135b0db 260 || ((u_short *)ip)[4] != ((u_short *)&cs->cs_ip)[4]
Yann 0:f30e2135b0db 261 || TCPH_OFFSET(th) != TCPH_OFFSET(oth)
Yann 0:f30e2135b0db 262 || (deltaS > 5 && BCMP(ip + 1, &cs->cs_ip + 1, (deltaS - 5) << 2))
Yann 0:f30e2135b0db 263 || (TCPH_OFFSET(th) > 5 && BCMP(th + 1, oth + 1, (TCPH_OFFSET(th) - 5) << 2))) {
Yann 0:f30e2135b0db 264 goto uncompressed;
Yann 0:f30e2135b0db 265 }
Yann 0:f30e2135b0db 266
Yann 0:f30e2135b0db 267 /*
Yann 0:f30e2135b0db 268 * Figure out which of the changing fields changed. The
Yann 0:f30e2135b0db 269 * receiver expects changes in the order: urgent, window,
Yann 0:f30e2135b0db 270 * ack, seq (the order minimizes the number of temporaries
Yann 0:f30e2135b0db 271 * needed in this section of code).
Yann 0:f30e2135b0db 272 */
Yann 0:f30e2135b0db 273 if (TCPH_FLAGS(th) & TCP_URG) {
Yann 0:f30e2135b0db 274 deltaS = ntohs(th->urgp);
Yann 0:f30e2135b0db 275 ENCODEZ(deltaS);
Yann 0:f30e2135b0db 276 changes |= NEW_U;
Yann 0:f30e2135b0db 277 } else if (th->urgp != oth->urgp) {
Yann 0:f30e2135b0db 278 /* argh! URG not set but urp changed -- a sensible
Yann 0:f30e2135b0db 279 * implementation should never do this but RFC793
Yann 0:f30e2135b0db 280 * doesn't prohibit the change so we have to deal
Yann 0:f30e2135b0db 281 * with it. */
Yann 0:f30e2135b0db 282 goto uncompressed;
Yann 0:f30e2135b0db 283 }
Yann 0:f30e2135b0db 284
Yann 0:f30e2135b0db 285 if ((deltaS = (u_short)(ntohs(th->wnd) - ntohs(oth->wnd))) != 0) {
Yann 0:f30e2135b0db 286 ENCODE(deltaS);
Yann 0:f30e2135b0db 287 changes |= NEW_W;
Yann 0:f30e2135b0db 288 }
Yann 0:f30e2135b0db 289
Yann 0:f30e2135b0db 290 if ((deltaL = ntohl(th->ackno) - ntohl(oth->ackno)) != 0) {
Yann 0:f30e2135b0db 291 if (deltaL > 0xffff) {
Yann 0:f30e2135b0db 292 goto uncompressed;
Yann 0:f30e2135b0db 293 }
Yann 0:f30e2135b0db 294 deltaA = (u_short)deltaL;
Yann 0:f30e2135b0db 295 ENCODE(deltaA);
Yann 0:f30e2135b0db 296 changes |= NEW_A;
Yann 0:f30e2135b0db 297 }
Yann 0:f30e2135b0db 298
Yann 0:f30e2135b0db 299 if ((deltaL = ntohl(th->seqno) - ntohl(oth->seqno)) != 0) {
Yann 0:f30e2135b0db 300 if (deltaL > 0xffff) {
Yann 0:f30e2135b0db 301 goto uncompressed;
Yann 0:f30e2135b0db 302 }
Yann 0:f30e2135b0db 303 deltaS = (u_short)deltaL;
Yann 0:f30e2135b0db 304 ENCODE(deltaS);
Yann 0:f30e2135b0db 305 changes |= NEW_S;
Yann 0:f30e2135b0db 306 }
Yann 0:f30e2135b0db 307
Yann 0:f30e2135b0db 308 switch(changes) {
Yann 0:f30e2135b0db 309 case 0:
Yann 0:f30e2135b0db 310 /*
Yann 0:f30e2135b0db 311 * Nothing changed. If this packet contains data and the
Yann 0:f30e2135b0db 312 * last one didn't, this is probably a data packet following
Yann 0:f30e2135b0db 313 * an ack (normal on an interactive connection) and we send
Yann 0:f30e2135b0db 314 * it compressed. Otherwise it's probably a retransmit,
Yann 0:f30e2135b0db 315 * retransmitted ack or window probe. Send it uncompressed
Yann 0:f30e2135b0db 316 * in case the other side missed the compressed version.
Yann 0:f30e2135b0db 317 */
Yann 0:f30e2135b0db 318 if (IPH_LEN(ip) != IPH_LEN(&cs->cs_ip) &&
Yann 0:f30e2135b0db 319 ntohs(IPH_LEN(&cs->cs_ip)) == hlen) {
Yann 0:f30e2135b0db 320 break;
Yann 0:f30e2135b0db 321 }
Yann 0:f30e2135b0db 322
Yann 0:f30e2135b0db 323 /* (fall through) */
Yann 0:f30e2135b0db 324
Yann 0:f30e2135b0db 325 case SPECIAL_I:
Yann 0:f30e2135b0db 326 case SPECIAL_D:
Yann 0:f30e2135b0db 327 /*
Yann 0:f30e2135b0db 328 * actual changes match one of our special case encodings --
Yann 0:f30e2135b0db 329 * send packet uncompressed.
Yann 0:f30e2135b0db 330 */
Yann 0:f30e2135b0db 331 goto uncompressed;
Yann 0:f30e2135b0db 332
Yann 0:f30e2135b0db 333 case NEW_S|NEW_A:
Yann 0:f30e2135b0db 334 if (deltaS == deltaA && deltaS == ntohs(IPH_LEN(&cs->cs_ip)) - hlen) {
Yann 0:f30e2135b0db 335 /* special case for echoed terminal traffic */
Yann 0:f30e2135b0db 336 changes = SPECIAL_I;
Yann 0:f30e2135b0db 337 cp = new_seq;
Yann 0:f30e2135b0db 338 }
Yann 0:f30e2135b0db 339 break;
Yann 0:f30e2135b0db 340
Yann 0:f30e2135b0db 341 case NEW_S:
Yann 0:f30e2135b0db 342 if (deltaS == ntohs(IPH_LEN(&cs->cs_ip)) - hlen) {
Yann 0:f30e2135b0db 343 /* special case for data xfer */
Yann 0:f30e2135b0db 344 changes = SPECIAL_D;
Yann 0:f30e2135b0db 345 cp = new_seq;
Yann 0:f30e2135b0db 346 }
Yann 0:f30e2135b0db 347 break;
Yann 0:f30e2135b0db 348 }
Yann 0:f30e2135b0db 349
Yann 0:f30e2135b0db 350 deltaS = (u_short)(ntohs(IPH_ID(ip)) - ntohs(IPH_ID(&cs->cs_ip)));
Yann 0:f30e2135b0db 351 if (deltaS != 1) {
Yann 0:f30e2135b0db 352 ENCODEZ(deltaS);
Yann 0:f30e2135b0db 353 changes |= NEW_I;
Yann 0:f30e2135b0db 354 }
Yann 0:f30e2135b0db 355 if (TCPH_FLAGS(th) & TCP_PSH) {
Yann 0:f30e2135b0db 356 changes |= TCP_PUSH_BIT;
Yann 0:f30e2135b0db 357 }
Yann 0:f30e2135b0db 358 /*
Yann 0:f30e2135b0db 359 * Grab the cksum before we overwrite it below. Then update our
Yann 0:f30e2135b0db 360 * state with this packet's header.
Yann 0:f30e2135b0db 361 */
Yann 0:f30e2135b0db 362 deltaA = ntohs(th->chksum);
Yann 0:f30e2135b0db 363 BCOPY(ip, &cs->cs_ip, hlen);
Yann 0:f30e2135b0db 364
Yann 0:f30e2135b0db 365 /*
Yann 0:f30e2135b0db 366 * We want to use the original packet as our compressed packet.
Yann 0:f30e2135b0db 367 * (cp - new_seq) is the number of bytes we need for compressed
Yann 0:f30e2135b0db 368 * sequence numbers. In addition we need one byte for the change
Yann 0:f30e2135b0db 369 * mask, one for the connection id and two for the tcp checksum.
Yann 0:f30e2135b0db 370 * So, (cp - new_seq) + 4 bytes of header are needed. hlen is how
Yann 0:f30e2135b0db 371 * many bytes of the original packet to toss so subtract the two to
Yann 0:f30e2135b0db 372 * get the new packet size.
Yann 0:f30e2135b0db 373 */
Yann 0:f30e2135b0db 374 deltaS = (u_short)(cp - new_seq);
Yann 0:f30e2135b0db 375 if (!comp->compressSlot || comp->last_xmit != cs->cs_id) {
Yann 0:f30e2135b0db 376 comp->last_xmit = cs->cs_id;
Yann 0:f30e2135b0db 377 hlen -= deltaS + 4;
Yann 0:f30e2135b0db 378 if(pbuf_header(pb, -hlen)){
Yann 0:f30e2135b0db 379 /* Can we cope with this failing? Just assert for now */
Yann 0:f30e2135b0db 380 LWIP_ASSERT("pbuf_header failed\n", 0);
Yann 0:f30e2135b0db 381 }
Yann 0:f30e2135b0db 382 cp = (u_char *)pb->payload;
Yann 0:f30e2135b0db 383 *cp++ = (u_char)(changes | NEW_C);
Yann 0:f30e2135b0db 384 *cp++ = cs->cs_id;
Yann 0:f30e2135b0db 385 } else {
Yann 0:f30e2135b0db 386 hlen -= deltaS + 3;
Yann 0:f30e2135b0db 387 if(pbuf_header(pb, -hlen)) {
Yann 0:f30e2135b0db 388 /* Can we cope with this failing? Just assert for now */
Yann 0:f30e2135b0db 389 LWIP_ASSERT("pbuf_header failed\n", 0);
Yann 0:f30e2135b0db 390 }
Yann 0:f30e2135b0db 391 cp = (u_char *)pb->payload;
Yann 0:f30e2135b0db 392 *cp++ = (u_char)changes;
Yann 0:f30e2135b0db 393 }
Yann 0:f30e2135b0db 394 *cp++ = (u_char)(deltaA >> 8);
Yann 0:f30e2135b0db 395 *cp++ = (u_char)deltaA;
Yann 0:f30e2135b0db 396 BCOPY(new_seq, cp, deltaS);
Yann 0:f30e2135b0db 397 INCR(vjs_compressed);
Yann 0:f30e2135b0db 398 return (TYPE_COMPRESSED_TCP);
Yann 0:f30e2135b0db 399
Yann 0:f30e2135b0db 400 /*
Yann 0:f30e2135b0db 401 * Update connection state cs & send uncompressed packet (that is,
Yann 0:f30e2135b0db 402 * a regular ip/tcp packet but with the 'conversation id' we hope
Yann 0:f30e2135b0db 403 * to use on future compressed packets in the protocol field).
Yann 0:f30e2135b0db 404 */
Yann 0:f30e2135b0db 405 uncompressed:
Yann 0:f30e2135b0db 406 BCOPY(ip, &cs->cs_ip, hlen);
Yann 0:f30e2135b0db 407 IPH_PROTO_SET(ip, cs->cs_id);
Yann 0:f30e2135b0db 408 comp->last_xmit = cs->cs_id;
Yann 0:f30e2135b0db 409 return (TYPE_UNCOMPRESSED_TCP);
Yann 0:f30e2135b0db 410 }
Yann 0:f30e2135b0db 411
Yann 0:f30e2135b0db 412 /*
Yann 0:f30e2135b0db 413 * Called when we may have missed a packet.
Yann 0:f30e2135b0db 414 */
Yann 0:f30e2135b0db 415 void
Yann 0:f30e2135b0db 416 vj_uncompress_err(struct vjcompress *comp)
Yann 0:f30e2135b0db 417 {
Yann 0:f30e2135b0db 418 comp->flags |= VJF_TOSS;
Yann 0:f30e2135b0db 419 INCR(vjs_errorin);
Yann 0:f30e2135b0db 420 }
Yann 0:f30e2135b0db 421
Yann 0:f30e2135b0db 422 /*
Yann 0:f30e2135b0db 423 * "Uncompress" a packet of type TYPE_UNCOMPRESSED_TCP.
Yann 0:f30e2135b0db 424 * Return 0 on success, -1 on failure.
Yann 0:f30e2135b0db 425 */
Yann 0:f30e2135b0db 426 int
Yann 0:f30e2135b0db 427 vj_uncompress_uncomp(struct pbuf *nb, struct vjcompress *comp)
Yann 0:f30e2135b0db 428 {
Yann 0:f30e2135b0db 429 register u_int hlen;
Yann 0:f30e2135b0db 430 register struct cstate *cs;
Yann 0:f30e2135b0db 431 register struct ip_hdr *ip;
Yann 0:f30e2135b0db 432
Yann 0:f30e2135b0db 433 ip = (struct ip_hdr *)nb->payload;
Yann 0:f30e2135b0db 434 hlen = IPH_HL(ip) << 2;
Yann 0:f30e2135b0db 435 if (IPH_PROTO(ip) >= MAX_SLOTS
Yann 0:f30e2135b0db 436 || hlen + sizeof(struct tcp_hdr) > nb->len
Yann 0:f30e2135b0db 437 || (hlen += TCPH_OFFSET(((struct tcp_hdr *)&((char *)ip)[hlen])) << 2)
Yann 0:f30e2135b0db 438 > nb->len
Yann 0:f30e2135b0db 439 || hlen > MAX_HDR) {
Yann 0:f30e2135b0db 440 PPPDEBUG(LOG_INFO, ("vj_uncompress_uncomp: bad cid=%d, hlen=%d buflen=%d\n",
Yann 0:f30e2135b0db 441 IPH_PROTO(ip), hlen, nb->len));
Yann 0:f30e2135b0db 442 comp->flags |= VJF_TOSS;
Yann 0:f30e2135b0db 443 INCR(vjs_errorin);
Yann 0:f30e2135b0db 444 return -1;
Yann 0:f30e2135b0db 445 }
Yann 0:f30e2135b0db 446 cs = &comp->rstate[comp->last_recv = IPH_PROTO(ip)];
Yann 0:f30e2135b0db 447 comp->flags &=~ VJF_TOSS;
Yann 0:f30e2135b0db 448 IPH_PROTO_SET(ip, IP_PROTO_TCP);
Yann 0:f30e2135b0db 449 BCOPY(ip, &cs->cs_ip, hlen);
Yann 0:f30e2135b0db 450 cs->cs_hlen = (u_short)hlen;
Yann 0:f30e2135b0db 451 INCR(vjs_uncompressedin);
Yann 0:f30e2135b0db 452 return 0;
Yann 0:f30e2135b0db 453 }
Yann 0:f30e2135b0db 454
Yann 0:f30e2135b0db 455 /*
Yann 0:f30e2135b0db 456 * Uncompress a packet of type TYPE_COMPRESSED_TCP.
Yann 0:f30e2135b0db 457 * The packet is composed of a buffer chain and the first buffer
Yann 0:f30e2135b0db 458 * must contain an accurate chain length.
Yann 0:f30e2135b0db 459 * The first buffer must include the entire compressed TCP/IP header.
Yann 0:f30e2135b0db 460 * This procedure replaces the compressed header with the uncompressed
Yann 0:f30e2135b0db 461 * header and returns the length of the VJ header.
Yann 0:f30e2135b0db 462 */
Yann 0:f30e2135b0db 463 int
Yann 0:f30e2135b0db 464 vj_uncompress_tcp(struct pbuf **nb, struct vjcompress *comp)
Yann 0:f30e2135b0db 465 {
Yann 0:f30e2135b0db 466 u_char *cp;
Yann 0:f30e2135b0db 467 struct tcp_hdr *th;
Yann 0:f30e2135b0db 468 struct cstate *cs;
Yann 0:f30e2135b0db 469 u_short *bp;
Yann 0:f30e2135b0db 470 struct pbuf *n0 = *nb;
Yann 0:f30e2135b0db 471 u32_t tmp;
Yann 0:f30e2135b0db 472 u_int vjlen, hlen, changes;
Yann 0:f30e2135b0db 473
Yann 0:f30e2135b0db 474 INCR(vjs_compressedin);
Yann 0:f30e2135b0db 475 cp = (u_char *)n0->payload;
Yann 0:f30e2135b0db 476 changes = *cp++;
Yann 0:f30e2135b0db 477 if (changes & NEW_C) {
Yann 0:f30e2135b0db 478 /*
Yann 0:f30e2135b0db 479 * Make sure the state index is in range, then grab the state.
Yann 0:f30e2135b0db 480 * If we have a good state index, clear the 'discard' flag.
Yann 0:f30e2135b0db 481 */
Yann 0:f30e2135b0db 482 if (*cp >= MAX_SLOTS) {
Yann 0:f30e2135b0db 483 PPPDEBUG(LOG_INFO, ("vj_uncompress_tcp: bad cid=%d\n", *cp));
Yann 0:f30e2135b0db 484 goto bad;
Yann 0:f30e2135b0db 485 }
Yann 0:f30e2135b0db 486
Yann 0:f30e2135b0db 487 comp->flags &=~ VJF_TOSS;
Yann 0:f30e2135b0db 488 comp->last_recv = *cp++;
Yann 0:f30e2135b0db 489 } else {
Yann 0:f30e2135b0db 490 /*
Yann 0:f30e2135b0db 491 * this packet has an implicit state index. If we've
Yann 0:f30e2135b0db 492 * had a line error since the last time we got an
Yann 0:f30e2135b0db 493 * explicit state index, we have to toss the packet.
Yann 0:f30e2135b0db 494 */
Yann 0:f30e2135b0db 495 if (comp->flags & VJF_TOSS) {
Yann 0:f30e2135b0db 496 PPPDEBUG(LOG_INFO, ("vj_uncompress_tcp: tossing\n"));
Yann 0:f30e2135b0db 497 INCR(vjs_tossed);
Yann 0:f30e2135b0db 498 return (-1);
Yann 0:f30e2135b0db 499 }
Yann 0:f30e2135b0db 500 }
Yann 0:f30e2135b0db 501 cs = &comp->rstate[comp->last_recv];
Yann 0:f30e2135b0db 502 hlen = IPH_HL(&cs->cs_ip) << 2;
Yann 0:f30e2135b0db 503 th = (struct tcp_hdr *)&((u_char *)&cs->cs_ip)[hlen];
Yann 0:f30e2135b0db 504 th->chksum = htons((*cp << 8) | cp[1]);
Yann 0:f30e2135b0db 505 cp += 2;
Yann 0:f30e2135b0db 506 if (changes & TCP_PUSH_BIT) {
Yann 0:f30e2135b0db 507 TCPH_SET_FLAG(th, TCP_PSH);
Yann 0:f30e2135b0db 508 } else {
Yann 0:f30e2135b0db 509 TCPH_UNSET_FLAG(th, TCP_PSH);
Yann 0:f30e2135b0db 510 }
Yann 0:f30e2135b0db 511
Yann 0:f30e2135b0db 512 switch (changes & SPECIALS_MASK) {
Yann 0:f30e2135b0db 513 case SPECIAL_I:
Yann 0:f30e2135b0db 514 {
Yann 0:f30e2135b0db 515 register u32_t i = ntohs(IPH_LEN(&cs->cs_ip)) - cs->cs_hlen;
Yann 0:f30e2135b0db 516 /* some compilers can't nest inline assembler.. */
Yann 0:f30e2135b0db 517 tmp = ntohl(th->ackno) + i;
Yann 0:f30e2135b0db 518 th->ackno = htonl(tmp);
Yann 0:f30e2135b0db 519 tmp = ntohl(th->seqno) + i;
Yann 0:f30e2135b0db 520 th->seqno = htonl(tmp);
Yann 0:f30e2135b0db 521 }
Yann 0:f30e2135b0db 522 break;
Yann 0:f30e2135b0db 523
Yann 0:f30e2135b0db 524 case SPECIAL_D:
Yann 0:f30e2135b0db 525 /* some compilers can't nest inline assembler.. */
Yann 0:f30e2135b0db 526 tmp = ntohl(th->seqno) + ntohs(IPH_LEN(&cs->cs_ip)) - cs->cs_hlen;
Yann 0:f30e2135b0db 527 th->seqno = htonl(tmp);
Yann 0:f30e2135b0db 528 break;
Yann 0:f30e2135b0db 529
Yann 0:f30e2135b0db 530 default:
Yann 0:f30e2135b0db 531 if (changes & NEW_U) {
Yann 0:f30e2135b0db 532 TCPH_SET_FLAG(th, TCP_URG);
Yann 0:f30e2135b0db 533 DECODEU(th->urgp);
Yann 0:f30e2135b0db 534 } else {
Yann 0:f30e2135b0db 535 TCPH_UNSET_FLAG(th, TCP_URG);
Yann 0:f30e2135b0db 536 }
Yann 0:f30e2135b0db 537 if (changes & NEW_W) {
Yann 0:f30e2135b0db 538 DECODES(th->wnd);
Yann 0:f30e2135b0db 539 }
Yann 0:f30e2135b0db 540 if (changes & NEW_A) {
Yann 0:f30e2135b0db 541 DECODEL(th->ackno);
Yann 0:f30e2135b0db 542 }
Yann 0:f30e2135b0db 543 if (changes & NEW_S) {
Yann 0:f30e2135b0db 544 DECODEL(th->seqno);
Yann 0:f30e2135b0db 545 }
Yann 0:f30e2135b0db 546 break;
Yann 0:f30e2135b0db 547 }
Yann 0:f30e2135b0db 548 if (changes & NEW_I) {
Yann 0:f30e2135b0db 549 DECODES(cs->cs_ip._id);
Yann 0:f30e2135b0db 550 } else {
Yann 0:f30e2135b0db 551 IPH_ID_SET(&cs->cs_ip, ntohs(IPH_ID(&cs->cs_ip)) + 1);
Yann 0:f30e2135b0db 552 IPH_ID_SET(&cs->cs_ip, htons(IPH_ID(&cs->cs_ip)));
Yann 0:f30e2135b0db 553 }
Yann 0:f30e2135b0db 554
Yann 0:f30e2135b0db 555 /*
Yann 0:f30e2135b0db 556 * At this point, cp points to the first byte of data in the
Yann 0:f30e2135b0db 557 * packet. Fill in the IP total length and update the IP
Yann 0:f30e2135b0db 558 * header checksum.
Yann 0:f30e2135b0db 559 */
Yann 0:f30e2135b0db 560 vjlen = (u_short)(cp - (u_char*)n0->payload);
Yann 0:f30e2135b0db 561 if (n0->len < vjlen) {
Yann 0:f30e2135b0db 562 /*
Yann 0:f30e2135b0db 563 * We must have dropped some characters (crc should detect
Yann 0:f30e2135b0db 564 * this but the old slip framing won't)
Yann 0:f30e2135b0db 565 */
Yann 0:f30e2135b0db 566 PPPDEBUG(LOG_INFO, ("vj_uncompress_tcp: head buffer %d too short %d\n",
Yann 0:f30e2135b0db 567 n0->len, vjlen));
Yann 0:f30e2135b0db 568 goto bad;
Yann 0:f30e2135b0db 569 }
Yann 0:f30e2135b0db 570
Yann 0:f30e2135b0db 571 #if BYTE_ORDER == LITTLE_ENDIAN
Yann 0:f30e2135b0db 572 tmp = n0->tot_len - vjlen + cs->cs_hlen;
Yann 0:f30e2135b0db 573 IPH_LEN_SET(&cs->cs_ip, htons((u_short)tmp));
Yann 0:f30e2135b0db 574 #else
Yann 0:f30e2135b0db 575 IPH_LEN_SET(&cs->cs_ip, htons(n0->tot_len - vjlen + cs->cs_hlen));
Yann 0:f30e2135b0db 576 #endif
Yann 0:f30e2135b0db 577
Yann 0:f30e2135b0db 578 /* recompute the ip header checksum */
Yann 0:f30e2135b0db 579 bp = (u_short *) &cs->cs_ip;
Yann 0:f30e2135b0db 580 IPH_CHKSUM_SET(&cs->cs_ip, 0);
Yann 0:f30e2135b0db 581 for (tmp = 0; hlen > 0; hlen -= 2) {
Yann 0:f30e2135b0db 582 tmp += *bp++;
Yann 0:f30e2135b0db 583 }
Yann 0:f30e2135b0db 584 tmp = (tmp & 0xffff) + (tmp >> 16);
Yann 0:f30e2135b0db 585 tmp = (tmp & 0xffff) + (tmp >> 16);
Yann 0:f30e2135b0db 586 IPH_CHKSUM_SET(&cs->cs_ip, (u_short)(~tmp));
Yann 0:f30e2135b0db 587
Yann 0:f30e2135b0db 588 /* Remove the compressed header and prepend the uncompressed header. */
Yann 0:f30e2135b0db 589 if(pbuf_header(n0, -((s16_t)(vjlen)))) {
Yann 0:f30e2135b0db 590 /* Can we cope with this failing? Just assert for now */
Yann 0:f30e2135b0db 591 LWIP_ASSERT("pbuf_header failed\n", 0);
Yann 0:f30e2135b0db 592 goto bad;
Yann 0:f30e2135b0db 593 }
Yann 0:f30e2135b0db 594
Yann 0:f30e2135b0db 595 if(LWIP_MEM_ALIGN(n0->payload) != n0->payload) {
Yann 0:f30e2135b0db 596 struct pbuf *np, *q;
Yann 0:f30e2135b0db 597 u8_t *bufptr;
Yann 0:f30e2135b0db 598
Yann 0:f30e2135b0db 599 np = pbuf_alloc(PBUF_RAW, n0->len + cs->cs_hlen, PBUF_POOL);
Yann 0:f30e2135b0db 600 if(!np) {
Yann 0:f30e2135b0db 601 PPPDEBUG(LOG_WARNING, ("vj_uncompress_tcp: realign failed\n"));
Yann 0:f30e2135b0db 602 goto bad;
Yann 0:f30e2135b0db 603 }
Yann 0:f30e2135b0db 604
Yann 0:f30e2135b0db 605 if(pbuf_header(np, -cs->cs_hlen)) {
Yann 0:f30e2135b0db 606 /* Can we cope with this failing? Just assert for now */
Yann 0:f30e2135b0db 607 LWIP_ASSERT("pbuf_header failed\n", 0);
Yann 0:f30e2135b0db 608 goto bad;
Yann 0:f30e2135b0db 609 }
Yann 0:f30e2135b0db 610
Yann 0:f30e2135b0db 611 bufptr = (u8_t *)n0->payload;
Yann 0:f30e2135b0db 612 for(q = np; q != NULL; q = q->next) {
Yann 0:f30e2135b0db 613 MEMCPY(q->payload, bufptr, q->len);
Yann 0:f30e2135b0db 614 bufptr += q->len;
Yann 0:f30e2135b0db 615 }
Yann 0:f30e2135b0db 616
Yann 0:f30e2135b0db 617 if(n0->next) {
Yann 0:f30e2135b0db 618 pbuf_chain(np, n0->next);
Yann 0:f30e2135b0db 619 pbuf_dechain(n0);
Yann 0:f30e2135b0db 620 }
Yann 0:f30e2135b0db 621 pbuf_free(n0);
Yann 0:f30e2135b0db 622 n0 = np;
Yann 0:f30e2135b0db 623 }
Yann 0:f30e2135b0db 624
Yann 0:f30e2135b0db 625 if(pbuf_header(n0, cs->cs_hlen)) {
Yann 0:f30e2135b0db 626 struct pbuf *np;
Yann 0:f30e2135b0db 627
Yann 0:f30e2135b0db 628 LWIP_ASSERT("vj_uncompress_tcp: cs->cs_hlen <= PBUF_POOL_BUFSIZE", cs->cs_hlen <= PBUF_POOL_BUFSIZE);
Yann 0:f30e2135b0db 629 np = pbuf_alloc(PBUF_RAW, cs->cs_hlen, PBUF_POOL);
Yann 0:f30e2135b0db 630 if(!np) {
Yann 0:f30e2135b0db 631 PPPDEBUG(LOG_WARNING, ("vj_uncompress_tcp: prepend failed\n"));
Yann 0:f30e2135b0db 632 goto bad;
Yann 0:f30e2135b0db 633 }
Yann 0:f30e2135b0db 634 pbuf_cat(np, n0);
Yann 0:f30e2135b0db 635 n0 = np;
Yann 0:f30e2135b0db 636 }
Yann 0:f30e2135b0db 637 LWIP_ASSERT("n0->len >= cs->cs_hlen", n0->len >= cs->cs_hlen);
Yann 0:f30e2135b0db 638 MEMCPY(n0->payload, &cs->cs_ip, cs->cs_hlen);
Yann 0:f30e2135b0db 639
Yann 0:f30e2135b0db 640 *nb = n0;
Yann 0:f30e2135b0db 641
Yann 0:f30e2135b0db 642 return vjlen;
Yann 0:f30e2135b0db 643
Yann 0:f30e2135b0db 644 bad:
Yann 0:f30e2135b0db 645 comp->flags |= VJF_TOSS;
Yann 0:f30e2135b0db 646 INCR(vjs_errorin);
Yann 0:f30e2135b0db 647 return (-1);
Yann 0:f30e2135b0db 648 }
Yann 0:f30e2135b0db 649
Yann 0:f30e2135b0db 650 #endif /* VJ_SUPPORT */
Yann 0:f30e2135b0db 651
Yann 0:f30e2135b0db 652 #endif /* PPP_SUPPORT */