LwIP with PPP & Ethernet integration
This is the mbed port of the LwIP stack: http://savannah.nongnu.org/projects/lwip/
It includes contributed content from NXP's port for LPCxxxx devices: http://www.lpcware.com/content/project/lightweight-ip-lwip-networking-stack
Licence
LwIP is licenced under the BSD licence:
Copyright (c) 2001-2004 Swedish Institute of Computer Science. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 3. The name of the author may not be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
src/netif/ppp/vj.c@2:1a87f74b8e3b, 2012-05-25 (annotated)
- Committer:
- donatien
- Date:
- Fri May 25 08:56:35 2012 +0000
- Revision:
- 2:1a87f74b8e3b
- Parent:
- 0:8e01dca41002
Removed compilation of EMAC driver when using PPP
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
donatien | 0:8e01dca41002 | 1 | /* |
donatien | 0:8e01dca41002 | 2 | * Routines to compress and uncompess tcp packets (for transmission |
donatien | 0:8e01dca41002 | 3 | * over low speed serial lines. |
donatien | 0:8e01dca41002 | 4 | * |
donatien | 0:8e01dca41002 | 5 | * Copyright (c) 1989 Regents of the University of California. |
donatien | 0:8e01dca41002 | 6 | * All rights reserved. |
donatien | 0:8e01dca41002 | 7 | * |
donatien | 0:8e01dca41002 | 8 | * Redistribution and use in source and binary forms are permitted |
donatien | 0:8e01dca41002 | 9 | * provided that the above copyright notice and this paragraph are |
donatien | 0:8e01dca41002 | 10 | * duplicated in all such forms and that any documentation, |
donatien | 0:8e01dca41002 | 11 | * advertising materials, and other materials related to such |
donatien | 0:8e01dca41002 | 12 | * distribution and use acknowledge that the software was developed |
donatien | 0:8e01dca41002 | 13 | * by the University of California, Berkeley. The name of the |
donatien | 0:8e01dca41002 | 14 | * University may not be used to endorse or promote products derived |
donatien | 0:8e01dca41002 | 15 | * from this software without specific prior written permission. |
donatien | 0:8e01dca41002 | 16 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
donatien | 0:8e01dca41002 | 17 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
donatien | 0:8e01dca41002 | 18 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
donatien | 0:8e01dca41002 | 19 | * |
donatien | 0:8e01dca41002 | 20 | * Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989: |
donatien | 0:8e01dca41002 | 21 | * Initial distribution. |
donatien | 0:8e01dca41002 | 22 | * |
donatien | 0:8e01dca41002 | 23 | * Modified June 1993 by Paul Mackerras, paulus@cs.anu.edu.au, |
donatien | 0:8e01dca41002 | 24 | * so that the entire packet being decompressed doesn't have |
donatien | 0:8e01dca41002 | 25 | * to be in contiguous memory (just the compressed header). |
donatien | 0:8e01dca41002 | 26 | * |
donatien | 0:8e01dca41002 | 27 | * Modified March 1998 by Guy Lancaster, glanca@gesn.com, |
donatien | 0:8e01dca41002 | 28 | * for a 16 bit processor. |
donatien | 0:8e01dca41002 | 29 | */ |
donatien | 0:8e01dca41002 | 30 | |
donatien | 0:8e01dca41002 | 31 | #include "lwip/opt.h" |
donatien | 0:8e01dca41002 | 32 | |
donatien | 0:8e01dca41002 | 33 | #if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */ |
donatien | 0:8e01dca41002 | 34 | |
donatien | 0:8e01dca41002 | 35 | #include "ppp.h" |
donatien | 0:8e01dca41002 | 36 | #include "pppdebug.h" |
donatien | 0:8e01dca41002 | 37 | |
donatien | 0:8e01dca41002 | 38 | #include "vj.h" |
donatien | 0:8e01dca41002 | 39 | |
donatien | 0:8e01dca41002 | 40 | #include <string.h> |
donatien | 0:8e01dca41002 | 41 | |
donatien | 0:8e01dca41002 | 42 | #if VJ_SUPPORT |
donatien | 0:8e01dca41002 | 43 | |
donatien | 0:8e01dca41002 | 44 | #if LINK_STATS |
donatien | 0:8e01dca41002 | 45 | #define INCR(counter) ++comp->stats.counter |
donatien | 0:8e01dca41002 | 46 | #else |
donatien | 0:8e01dca41002 | 47 | #define INCR(counter) |
donatien | 0:8e01dca41002 | 48 | #endif |
donatien | 0:8e01dca41002 | 49 | |
donatien | 0:8e01dca41002 | 50 | void |
donatien | 0:8e01dca41002 | 51 | vj_compress_init(struct vjcompress *comp) |
donatien | 0:8e01dca41002 | 52 | { |
donatien | 0:8e01dca41002 | 53 | register u_char i; |
donatien | 0:8e01dca41002 | 54 | register struct cstate *tstate = comp->tstate; |
donatien | 0:8e01dca41002 | 55 | |
donatien | 0:8e01dca41002 | 56 | #if MAX_SLOTS == 0 |
donatien | 0:8e01dca41002 | 57 | memset((char *)comp, 0, sizeof(*comp)); |
donatien | 0:8e01dca41002 | 58 | #endif |
donatien | 0:8e01dca41002 | 59 | comp->maxSlotIndex = MAX_SLOTS - 1; |
donatien | 0:8e01dca41002 | 60 | comp->compressSlot = 0; /* Disable slot ID compression by default. */ |
donatien | 0:8e01dca41002 | 61 | for (i = MAX_SLOTS - 1; i > 0; --i) { |
donatien | 0:8e01dca41002 | 62 | tstate[i].cs_id = i; |
donatien | 0:8e01dca41002 | 63 | tstate[i].cs_next = &tstate[i - 1]; |
donatien | 0:8e01dca41002 | 64 | } |
donatien | 0:8e01dca41002 | 65 | tstate[0].cs_next = &tstate[MAX_SLOTS - 1]; |
donatien | 0:8e01dca41002 | 66 | tstate[0].cs_id = 0; |
donatien | 0:8e01dca41002 | 67 | comp->last_cs = &tstate[0]; |
donatien | 0:8e01dca41002 | 68 | comp->last_recv = 255; |
donatien | 0:8e01dca41002 | 69 | comp->last_xmit = 255; |
donatien | 0:8e01dca41002 | 70 | comp->flags = VJF_TOSS; |
donatien | 0:8e01dca41002 | 71 | } |
donatien | 0:8e01dca41002 | 72 | |
donatien | 0:8e01dca41002 | 73 | |
donatien | 0:8e01dca41002 | 74 | /* ENCODE encodes a number that is known to be non-zero. ENCODEZ |
donatien | 0:8e01dca41002 | 75 | * checks for zero (since zero has to be encoded in the long, 3 byte |
donatien | 0:8e01dca41002 | 76 | * form). |
donatien | 0:8e01dca41002 | 77 | */ |
donatien | 0:8e01dca41002 | 78 | #define ENCODE(n) { \ |
donatien | 0:8e01dca41002 | 79 | if ((u_short)(n) >= 256) { \ |
donatien | 0:8e01dca41002 | 80 | *cp++ = 0; \ |
donatien | 0:8e01dca41002 | 81 | cp[1] = (u_char)(n); \ |
donatien | 0:8e01dca41002 | 82 | cp[0] = (u_char)((n) >> 8); \ |
donatien | 0:8e01dca41002 | 83 | cp += 2; \ |
donatien | 0:8e01dca41002 | 84 | } else { \ |
donatien | 0:8e01dca41002 | 85 | *cp++ = (u_char)(n); \ |
donatien | 0:8e01dca41002 | 86 | } \ |
donatien | 0:8e01dca41002 | 87 | } |
donatien | 0:8e01dca41002 | 88 | #define ENCODEZ(n) { \ |
donatien | 0:8e01dca41002 | 89 | if ((u_short)(n) >= 256 || (u_short)(n) == 0) { \ |
donatien | 0:8e01dca41002 | 90 | *cp++ = 0; \ |
donatien | 0:8e01dca41002 | 91 | cp[1] = (u_char)(n); \ |
donatien | 0:8e01dca41002 | 92 | cp[0] = (u_char)((n) >> 8); \ |
donatien | 0:8e01dca41002 | 93 | cp += 2; \ |
donatien | 0:8e01dca41002 | 94 | } else { \ |
donatien | 0:8e01dca41002 | 95 | *cp++ = (u_char)(n); \ |
donatien | 0:8e01dca41002 | 96 | } \ |
donatien | 0:8e01dca41002 | 97 | } |
donatien | 0:8e01dca41002 | 98 | |
donatien | 0:8e01dca41002 | 99 | #define DECODEL(f) { \ |
donatien | 0:8e01dca41002 | 100 | if (*cp == 0) {\ |
donatien | 0:8e01dca41002 | 101 | u32_t tmp = ntohl(f) + ((cp[1] << 8) | cp[2]); \ |
donatien | 0:8e01dca41002 | 102 | (f) = htonl(tmp); \ |
donatien | 0:8e01dca41002 | 103 | cp += 3; \ |
donatien | 0:8e01dca41002 | 104 | } else { \ |
donatien | 0:8e01dca41002 | 105 | u32_t tmp = ntohl(f) + (u32_t)*cp++; \ |
donatien | 0:8e01dca41002 | 106 | (f) = htonl(tmp); \ |
donatien | 0:8e01dca41002 | 107 | } \ |
donatien | 0:8e01dca41002 | 108 | } |
donatien | 0:8e01dca41002 | 109 | |
donatien | 0:8e01dca41002 | 110 | #define DECODES(f) { \ |
donatien | 0:8e01dca41002 | 111 | if (*cp == 0) {\ |
donatien | 0:8e01dca41002 | 112 | u_short tmp = ntohs(f) + (((u_short)cp[1] << 8) | cp[2]); \ |
donatien | 0:8e01dca41002 | 113 | (f) = htons(tmp); \ |
donatien | 0:8e01dca41002 | 114 | cp += 3; \ |
donatien | 0:8e01dca41002 | 115 | } else { \ |
donatien | 0:8e01dca41002 | 116 | u_short tmp = ntohs(f) + (u_short)*cp++; \ |
donatien | 0:8e01dca41002 | 117 | (f) = htons(tmp); \ |
donatien | 0:8e01dca41002 | 118 | } \ |
donatien | 0:8e01dca41002 | 119 | } |
donatien | 0:8e01dca41002 | 120 | |
donatien | 0:8e01dca41002 | 121 | #define DECODEU(f) { \ |
donatien | 0:8e01dca41002 | 122 | if (*cp == 0) {\ |
donatien | 0:8e01dca41002 | 123 | (f) = htons(((u_short)cp[1] << 8) | cp[2]); \ |
donatien | 0:8e01dca41002 | 124 | cp += 3; \ |
donatien | 0:8e01dca41002 | 125 | } else { \ |
donatien | 0:8e01dca41002 | 126 | (f) = htons((u_short)*cp++); \ |
donatien | 0:8e01dca41002 | 127 | } \ |
donatien | 0:8e01dca41002 | 128 | } |
donatien | 0:8e01dca41002 | 129 | |
donatien | 0:8e01dca41002 | 130 | /* |
donatien | 0:8e01dca41002 | 131 | * vj_compress_tcp - Attempt to do Van Jacobson header compression on a |
donatien | 0:8e01dca41002 | 132 | * packet. This assumes that nb and comp are not null and that the first |
donatien | 0:8e01dca41002 | 133 | * buffer of the chain contains a valid IP header. |
donatien | 0:8e01dca41002 | 134 | * Return the VJ type code indicating whether or not the packet was |
donatien | 0:8e01dca41002 | 135 | * compressed. |
donatien | 0:8e01dca41002 | 136 | */ |
donatien | 0:8e01dca41002 | 137 | u_int |
donatien | 0:8e01dca41002 | 138 | vj_compress_tcp(struct vjcompress *comp, struct pbuf *pb) |
donatien | 0:8e01dca41002 | 139 | { |
donatien | 0:8e01dca41002 | 140 | register struct ip_hdr *ip = (struct ip_hdr *)pb->payload; |
donatien | 0:8e01dca41002 | 141 | register struct cstate *cs = comp->last_cs->cs_next; |
donatien | 0:8e01dca41002 | 142 | register u_short hlen = IPH_HL(ip); |
donatien | 0:8e01dca41002 | 143 | register struct tcp_hdr *oth; |
donatien | 0:8e01dca41002 | 144 | register struct tcp_hdr *th; |
donatien | 0:8e01dca41002 | 145 | register u_short deltaS, deltaA; |
donatien | 0:8e01dca41002 | 146 | register u_long deltaL; |
donatien | 0:8e01dca41002 | 147 | register u_int changes = 0; |
donatien | 0:8e01dca41002 | 148 | u_char new_seq[16]; |
donatien | 0:8e01dca41002 | 149 | register u_char *cp = new_seq; |
donatien | 0:8e01dca41002 | 150 | |
donatien | 0:8e01dca41002 | 151 | /* |
donatien | 0:8e01dca41002 | 152 | * Check that the packet is IP proto TCP. |
donatien | 0:8e01dca41002 | 153 | */ |
donatien | 0:8e01dca41002 | 154 | if (IPH_PROTO(ip) != IP_PROTO_TCP) { |
donatien | 0:8e01dca41002 | 155 | return (TYPE_IP); |
donatien | 0:8e01dca41002 | 156 | } |
donatien | 0:8e01dca41002 | 157 | |
donatien | 0:8e01dca41002 | 158 | /* |
donatien | 0:8e01dca41002 | 159 | * Bail if this is an IP fragment or if the TCP packet isn't |
donatien | 0:8e01dca41002 | 160 | * `compressible' (i.e., ACK isn't set or some other control bit is |
donatien | 0:8e01dca41002 | 161 | * set). |
donatien | 0:8e01dca41002 | 162 | */ |
donatien | 0:8e01dca41002 | 163 | if ((IPH_OFFSET(ip) & PP_HTONS(0x3fff)) || pb->tot_len < 40) { |
donatien | 0:8e01dca41002 | 164 | return (TYPE_IP); |
donatien | 0:8e01dca41002 | 165 | } |
donatien | 0:8e01dca41002 | 166 | th = (struct tcp_hdr *)&((long *)ip)[hlen]; |
donatien | 0:8e01dca41002 | 167 | if ((TCPH_FLAGS(th) & (TCP_SYN|TCP_FIN|TCP_RST|TCP_ACK)) != TCP_ACK) { |
donatien | 0:8e01dca41002 | 168 | return (TYPE_IP); |
donatien | 0:8e01dca41002 | 169 | } |
donatien | 0:8e01dca41002 | 170 | /* |
donatien | 0:8e01dca41002 | 171 | * Packet is compressible -- we're going to send either a |
donatien | 0:8e01dca41002 | 172 | * COMPRESSED_TCP or UNCOMPRESSED_TCP packet. Either way we need |
donatien | 0:8e01dca41002 | 173 | * to locate (or create) the connection state. Special case the |
donatien | 0:8e01dca41002 | 174 | * most recently used connection since it's most likely to be used |
donatien | 0:8e01dca41002 | 175 | * again & we don't have to do any reordering if it's used. |
donatien | 0:8e01dca41002 | 176 | */ |
donatien | 0:8e01dca41002 | 177 | INCR(vjs_packets); |
donatien | 0:8e01dca41002 | 178 | if (!ip_addr_cmp(&ip->src, &cs->cs_ip.src) |
donatien | 0:8e01dca41002 | 179 | || !ip_addr_cmp(&ip->dest, &cs->cs_ip.dest) |
donatien | 0:8e01dca41002 | 180 | || *(long *)th != ((long *)&cs->cs_ip)[IPH_HL(&cs->cs_ip)]) { |
donatien | 0:8e01dca41002 | 181 | /* |
donatien | 0:8e01dca41002 | 182 | * Wasn't the first -- search for it. |
donatien | 0:8e01dca41002 | 183 | * |
donatien | 0:8e01dca41002 | 184 | * States are kept in a circularly linked list with |
donatien | 0:8e01dca41002 | 185 | * last_cs pointing to the end of the list. The |
donatien | 0:8e01dca41002 | 186 | * list is kept in lru order by moving a state to the |
donatien | 0:8e01dca41002 | 187 | * head of the list whenever it is referenced. Since |
donatien | 0:8e01dca41002 | 188 | * the list is short and, empirically, the connection |
donatien | 0:8e01dca41002 | 189 | * we want is almost always near the front, we locate |
donatien | 0:8e01dca41002 | 190 | * states via linear search. If we don't find a state |
donatien | 0:8e01dca41002 | 191 | * for the datagram, the oldest state is (re-)used. |
donatien | 0:8e01dca41002 | 192 | */ |
donatien | 0:8e01dca41002 | 193 | register struct cstate *lcs; |
donatien | 0:8e01dca41002 | 194 | register struct cstate *lastcs = comp->last_cs; |
donatien | 0:8e01dca41002 | 195 | |
donatien | 0:8e01dca41002 | 196 | do { |
donatien | 0:8e01dca41002 | 197 | lcs = cs; cs = cs->cs_next; |
donatien | 0:8e01dca41002 | 198 | INCR(vjs_searches); |
donatien | 0:8e01dca41002 | 199 | if (ip_addr_cmp(&ip->src, &cs->cs_ip.src) |
donatien | 0:8e01dca41002 | 200 | && ip_addr_cmp(&ip->dest, &cs->cs_ip.dest) |
donatien | 0:8e01dca41002 | 201 | && *(long *)th == ((long *)&cs->cs_ip)[IPH_HL(&cs->cs_ip)]) { |
donatien | 0:8e01dca41002 | 202 | goto found; |
donatien | 0:8e01dca41002 | 203 | } |
donatien | 0:8e01dca41002 | 204 | } while (cs != lastcs); |
donatien | 0:8e01dca41002 | 205 | |
donatien | 0:8e01dca41002 | 206 | /* |
donatien | 0:8e01dca41002 | 207 | * Didn't find it -- re-use oldest cstate. Send an |
donatien | 0:8e01dca41002 | 208 | * uncompressed packet that tells the other side what |
donatien | 0:8e01dca41002 | 209 | * connection number we're using for this conversation. |
donatien | 0:8e01dca41002 | 210 | * Note that since the state list is circular, the oldest |
donatien | 0:8e01dca41002 | 211 | * state points to the newest and we only need to set |
donatien | 0:8e01dca41002 | 212 | * last_cs to update the lru linkage. |
donatien | 0:8e01dca41002 | 213 | */ |
donatien | 0:8e01dca41002 | 214 | INCR(vjs_misses); |
donatien | 0:8e01dca41002 | 215 | comp->last_cs = lcs; |
donatien | 0:8e01dca41002 | 216 | hlen += TCPH_OFFSET(th); |
donatien | 0:8e01dca41002 | 217 | hlen <<= 2; |
donatien | 0:8e01dca41002 | 218 | /* Check that the IP/TCP headers are contained in the first buffer. */ |
donatien | 0:8e01dca41002 | 219 | if (hlen > pb->len) { |
donatien | 0:8e01dca41002 | 220 | return (TYPE_IP); |
donatien | 0:8e01dca41002 | 221 | } |
donatien | 0:8e01dca41002 | 222 | goto uncompressed; |
donatien | 0:8e01dca41002 | 223 | |
donatien | 0:8e01dca41002 | 224 | found: |
donatien | 0:8e01dca41002 | 225 | /* |
donatien | 0:8e01dca41002 | 226 | * Found it -- move to the front on the connection list. |
donatien | 0:8e01dca41002 | 227 | */ |
donatien | 0:8e01dca41002 | 228 | if (cs == lastcs) { |
donatien | 0:8e01dca41002 | 229 | comp->last_cs = lcs; |
donatien | 0:8e01dca41002 | 230 | } else { |
donatien | 0:8e01dca41002 | 231 | lcs->cs_next = cs->cs_next; |
donatien | 0:8e01dca41002 | 232 | cs->cs_next = lastcs->cs_next; |
donatien | 0:8e01dca41002 | 233 | lastcs->cs_next = cs; |
donatien | 0:8e01dca41002 | 234 | } |
donatien | 0:8e01dca41002 | 235 | } |
donatien | 0:8e01dca41002 | 236 | |
donatien | 0:8e01dca41002 | 237 | oth = (struct tcp_hdr *)&((long *)&cs->cs_ip)[hlen]; |
donatien | 0:8e01dca41002 | 238 | deltaS = hlen; |
donatien | 0:8e01dca41002 | 239 | hlen += TCPH_OFFSET(th); |
donatien | 0:8e01dca41002 | 240 | hlen <<= 2; |
donatien | 0:8e01dca41002 | 241 | /* Check that the IP/TCP headers are contained in the first buffer. */ |
donatien | 0:8e01dca41002 | 242 | if (hlen > pb->len) { |
donatien | 0:8e01dca41002 | 243 | PPPDEBUG(LOG_INFO, ("vj_compress_tcp: header len %d spans buffers\n", hlen)); |
donatien | 0:8e01dca41002 | 244 | return (TYPE_IP); |
donatien | 0:8e01dca41002 | 245 | } |
donatien | 0:8e01dca41002 | 246 | |
donatien | 0:8e01dca41002 | 247 | /* |
donatien | 0:8e01dca41002 | 248 | * Make sure that only what we expect to change changed. The first |
donatien | 0:8e01dca41002 | 249 | * line of the `if' checks the IP protocol version, header length & |
donatien | 0:8e01dca41002 | 250 | * type of service. The 2nd line checks the "Don't fragment" bit. |
donatien | 0:8e01dca41002 | 251 | * The 3rd line checks the time-to-live and protocol (the protocol |
donatien | 0:8e01dca41002 | 252 | * check is unnecessary but costless). The 4th line checks the TCP |
donatien | 0:8e01dca41002 | 253 | * header length. The 5th line checks IP options, if any. The 6th |
donatien | 0:8e01dca41002 | 254 | * line checks TCP options, if any. If any of these things are |
donatien | 0:8e01dca41002 | 255 | * different between the previous & current datagram, we send the |
donatien | 0:8e01dca41002 | 256 | * current datagram `uncompressed'. |
donatien | 0:8e01dca41002 | 257 | */ |
donatien | 0:8e01dca41002 | 258 | if (((u_short *)ip)[0] != ((u_short *)&cs->cs_ip)[0] |
donatien | 0:8e01dca41002 | 259 | || ((u_short *)ip)[3] != ((u_short *)&cs->cs_ip)[3] |
donatien | 0:8e01dca41002 | 260 | || ((u_short *)ip)[4] != ((u_short *)&cs->cs_ip)[4] |
donatien | 0:8e01dca41002 | 261 | || TCPH_OFFSET(th) != TCPH_OFFSET(oth) |
donatien | 0:8e01dca41002 | 262 | || (deltaS > 5 && BCMP(ip + 1, &cs->cs_ip + 1, (deltaS - 5) << 2)) |
donatien | 0:8e01dca41002 | 263 | || (TCPH_OFFSET(th) > 5 && BCMP(th + 1, oth + 1, (TCPH_OFFSET(th) - 5) << 2))) { |
donatien | 0:8e01dca41002 | 264 | goto uncompressed; |
donatien | 0:8e01dca41002 | 265 | } |
donatien | 0:8e01dca41002 | 266 | |
donatien | 0:8e01dca41002 | 267 | /* |
donatien | 0:8e01dca41002 | 268 | * Figure out which of the changing fields changed. The |
donatien | 0:8e01dca41002 | 269 | * receiver expects changes in the order: urgent, window, |
donatien | 0:8e01dca41002 | 270 | * ack, seq (the order minimizes the number of temporaries |
donatien | 0:8e01dca41002 | 271 | * needed in this section of code). |
donatien | 0:8e01dca41002 | 272 | */ |
donatien | 0:8e01dca41002 | 273 | if (TCPH_FLAGS(th) & TCP_URG) { |
donatien | 0:8e01dca41002 | 274 | deltaS = ntohs(th->urgp); |
donatien | 0:8e01dca41002 | 275 | ENCODEZ(deltaS); |
donatien | 0:8e01dca41002 | 276 | changes |= NEW_U; |
donatien | 0:8e01dca41002 | 277 | } else if (th->urgp != oth->urgp) { |
donatien | 0:8e01dca41002 | 278 | /* argh! URG not set but urp changed -- a sensible |
donatien | 0:8e01dca41002 | 279 | * implementation should never do this but RFC793 |
donatien | 0:8e01dca41002 | 280 | * doesn't prohibit the change so we have to deal |
donatien | 0:8e01dca41002 | 281 | * with it. */ |
donatien | 0:8e01dca41002 | 282 | goto uncompressed; |
donatien | 0:8e01dca41002 | 283 | } |
donatien | 0:8e01dca41002 | 284 | |
donatien | 0:8e01dca41002 | 285 | if ((deltaS = (u_short)(ntohs(th->wnd) - ntohs(oth->wnd))) != 0) { |
donatien | 0:8e01dca41002 | 286 | ENCODE(deltaS); |
donatien | 0:8e01dca41002 | 287 | changes |= NEW_W; |
donatien | 0:8e01dca41002 | 288 | } |
donatien | 0:8e01dca41002 | 289 | |
donatien | 0:8e01dca41002 | 290 | if ((deltaL = ntohl(th->ackno) - ntohl(oth->ackno)) != 0) { |
donatien | 0:8e01dca41002 | 291 | if (deltaL > 0xffff) { |
donatien | 0:8e01dca41002 | 292 | goto uncompressed; |
donatien | 0:8e01dca41002 | 293 | } |
donatien | 0:8e01dca41002 | 294 | deltaA = (u_short)deltaL; |
donatien | 0:8e01dca41002 | 295 | ENCODE(deltaA); |
donatien | 0:8e01dca41002 | 296 | changes |= NEW_A; |
donatien | 0:8e01dca41002 | 297 | } |
donatien | 0:8e01dca41002 | 298 | |
donatien | 0:8e01dca41002 | 299 | if ((deltaL = ntohl(th->seqno) - ntohl(oth->seqno)) != 0) { |
donatien | 0:8e01dca41002 | 300 | if (deltaL > 0xffff) { |
donatien | 0:8e01dca41002 | 301 | goto uncompressed; |
donatien | 0:8e01dca41002 | 302 | } |
donatien | 0:8e01dca41002 | 303 | deltaS = (u_short)deltaL; |
donatien | 0:8e01dca41002 | 304 | ENCODE(deltaS); |
donatien | 0:8e01dca41002 | 305 | changes |= NEW_S; |
donatien | 0:8e01dca41002 | 306 | } |
donatien | 0:8e01dca41002 | 307 | |
donatien | 0:8e01dca41002 | 308 | switch(changes) { |
donatien | 0:8e01dca41002 | 309 | case 0: |
donatien | 0:8e01dca41002 | 310 | /* |
donatien | 0:8e01dca41002 | 311 | * Nothing changed. If this packet contains data and the |
donatien | 0:8e01dca41002 | 312 | * last one didn't, this is probably a data packet following |
donatien | 0:8e01dca41002 | 313 | * an ack (normal on an interactive connection) and we send |
donatien | 0:8e01dca41002 | 314 | * it compressed. Otherwise it's probably a retransmit, |
donatien | 0:8e01dca41002 | 315 | * retransmitted ack or window probe. Send it uncompressed |
donatien | 0:8e01dca41002 | 316 | * in case the other side missed the compressed version. |
donatien | 0:8e01dca41002 | 317 | */ |
donatien | 0:8e01dca41002 | 318 | if (IPH_LEN(ip) != IPH_LEN(&cs->cs_ip) && |
donatien | 0:8e01dca41002 | 319 | ntohs(IPH_LEN(&cs->cs_ip)) == hlen) { |
donatien | 0:8e01dca41002 | 320 | break; |
donatien | 0:8e01dca41002 | 321 | } |
donatien | 0:8e01dca41002 | 322 | |
donatien | 0:8e01dca41002 | 323 | /* (fall through) */ |
donatien | 0:8e01dca41002 | 324 | |
donatien | 0:8e01dca41002 | 325 | case SPECIAL_I: |
donatien | 0:8e01dca41002 | 326 | case SPECIAL_D: |
donatien | 0:8e01dca41002 | 327 | /* |
donatien | 0:8e01dca41002 | 328 | * actual changes match one of our special case encodings -- |
donatien | 0:8e01dca41002 | 329 | * send packet uncompressed. |
donatien | 0:8e01dca41002 | 330 | */ |
donatien | 0:8e01dca41002 | 331 | goto uncompressed; |
donatien | 0:8e01dca41002 | 332 | |
donatien | 0:8e01dca41002 | 333 | case NEW_S|NEW_A: |
donatien | 0:8e01dca41002 | 334 | if (deltaS == deltaA && deltaS == ntohs(IPH_LEN(&cs->cs_ip)) - hlen) { |
donatien | 0:8e01dca41002 | 335 | /* special case for echoed terminal traffic */ |
donatien | 0:8e01dca41002 | 336 | changes = SPECIAL_I; |
donatien | 0:8e01dca41002 | 337 | cp = new_seq; |
donatien | 0:8e01dca41002 | 338 | } |
donatien | 0:8e01dca41002 | 339 | break; |
donatien | 0:8e01dca41002 | 340 | |
donatien | 0:8e01dca41002 | 341 | case NEW_S: |
donatien | 0:8e01dca41002 | 342 | if (deltaS == ntohs(IPH_LEN(&cs->cs_ip)) - hlen) { |
donatien | 0:8e01dca41002 | 343 | /* special case for data xfer */ |
donatien | 0:8e01dca41002 | 344 | changes = SPECIAL_D; |
donatien | 0:8e01dca41002 | 345 | cp = new_seq; |
donatien | 0:8e01dca41002 | 346 | } |
donatien | 0:8e01dca41002 | 347 | break; |
donatien | 0:8e01dca41002 | 348 | } |
donatien | 0:8e01dca41002 | 349 | |
donatien | 0:8e01dca41002 | 350 | deltaS = (u_short)(ntohs(IPH_ID(ip)) - ntohs(IPH_ID(&cs->cs_ip))); |
donatien | 0:8e01dca41002 | 351 | if (deltaS != 1) { |
donatien | 0:8e01dca41002 | 352 | ENCODEZ(deltaS); |
donatien | 0:8e01dca41002 | 353 | changes |= NEW_I; |
donatien | 0:8e01dca41002 | 354 | } |
donatien | 0:8e01dca41002 | 355 | if (TCPH_FLAGS(th) & TCP_PSH) { |
donatien | 0:8e01dca41002 | 356 | changes |= TCP_PUSH_BIT; |
donatien | 0:8e01dca41002 | 357 | } |
donatien | 0:8e01dca41002 | 358 | /* |
donatien | 0:8e01dca41002 | 359 | * Grab the cksum before we overwrite it below. Then update our |
donatien | 0:8e01dca41002 | 360 | * state with this packet's header. |
donatien | 0:8e01dca41002 | 361 | */ |
donatien | 0:8e01dca41002 | 362 | deltaA = ntohs(th->chksum); |
donatien | 0:8e01dca41002 | 363 | BCOPY(ip, &cs->cs_ip, hlen); |
donatien | 0:8e01dca41002 | 364 | |
donatien | 0:8e01dca41002 | 365 | /* |
donatien | 0:8e01dca41002 | 366 | * We want to use the original packet as our compressed packet. |
donatien | 0:8e01dca41002 | 367 | * (cp - new_seq) is the number of bytes we need for compressed |
donatien | 0:8e01dca41002 | 368 | * sequence numbers. In addition we need one byte for the change |
donatien | 0:8e01dca41002 | 369 | * mask, one for the connection id and two for the tcp checksum. |
donatien | 0:8e01dca41002 | 370 | * So, (cp - new_seq) + 4 bytes of header are needed. hlen is how |
donatien | 0:8e01dca41002 | 371 | * many bytes of the original packet to toss so subtract the two to |
donatien | 0:8e01dca41002 | 372 | * get the new packet size. |
donatien | 0:8e01dca41002 | 373 | */ |
donatien | 0:8e01dca41002 | 374 | deltaS = (u_short)(cp - new_seq); |
donatien | 0:8e01dca41002 | 375 | if (!comp->compressSlot || comp->last_xmit != cs->cs_id) { |
donatien | 0:8e01dca41002 | 376 | comp->last_xmit = cs->cs_id; |
donatien | 0:8e01dca41002 | 377 | hlen -= deltaS + 4; |
donatien | 0:8e01dca41002 | 378 | if(pbuf_header(pb, -hlen)){ |
donatien | 0:8e01dca41002 | 379 | /* Can we cope with this failing? Just assert for now */ |
donatien | 0:8e01dca41002 | 380 | LWIP_ASSERT("pbuf_header failed\n", 0); |
donatien | 0:8e01dca41002 | 381 | } |
donatien | 0:8e01dca41002 | 382 | cp = (u_char *)pb->payload; |
donatien | 0:8e01dca41002 | 383 | *cp++ = (u_char)(changes | NEW_C); |
donatien | 0:8e01dca41002 | 384 | *cp++ = cs->cs_id; |
donatien | 0:8e01dca41002 | 385 | } else { |
donatien | 0:8e01dca41002 | 386 | hlen -= deltaS + 3; |
donatien | 0:8e01dca41002 | 387 | if(pbuf_header(pb, -hlen)) { |
donatien | 0:8e01dca41002 | 388 | /* Can we cope with this failing? Just assert for now */ |
donatien | 0:8e01dca41002 | 389 | LWIP_ASSERT("pbuf_header failed\n", 0); |
donatien | 0:8e01dca41002 | 390 | } |
donatien | 0:8e01dca41002 | 391 | cp = (u_char *)pb->payload; |
donatien | 0:8e01dca41002 | 392 | *cp++ = (u_char)changes; |
donatien | 0:8e01dca41002 | 393 | } |
donatien | 0:8e01dca41002 | 394 | *cp++ = (u_char)(deltaA >> 8); |
donatien | 0:8e01dca41002 | 395 | *cp++ = (u_char)deltaA; |
donatien | 0:8e01dca41002 | 396 | BCOPY(new_seq, cp, deltaS); |
donatien | 0:8e01dca41002 | 397 | INCR(vjs_compressed); |
donatien | 0:8e01dca41002 | 398 | return (TYPE_COMPRESSED_TCP); |
donatien | 0:8e01dca41002 | 399 | |
donatien | 0:8e01dca41002 | 400 | /* |
donatien | 0:8e01dca41002 | 401 | * Update connection state cs & send uncompressed packet (that is, |
donatien | 0:8e01dca41002 | 402 | * a regular ip/tcp packet but with the 'conversation id' we hope |
donatien | 0:8e01dca41002 | 403 | * to use on future compressed packets in the protocol field). |
donatien | 0:8e01dca41002 | 404 | */ |
donatien | 0:8e01dca41002 | 405 | uncompressed: |
donatien | 0:8e01dca41002 | 406 | BCOPY(ip, &cs->cs_ip, hlen); |
donatien | 0:8e01dca41002 | 407 | IPH_PROTO_SET(ip, cs->cs_id); |
donatien | 0:8e01dca41002 | 408 | comp->last_xmit = cs->cs_id; |
donatien | 0:8e01dca41002 | 409 | return (TYPE_UNCOMPRESSED_TCP); |
donatien | 0:8e01dca41002 | 410 | } |
donatien | 0:8e01dca41002 | 411 | |
donatien | 0:8e01dca41002 | 412 | /* |
donatien | 0:8e01dca41002 | 413 | * Called when we may have missed a packet. |
donatien | 0:8e01dca41002 | 414 | */ |
donatien | 0:8e01dca41002 | 415 | void |
donatien | 0:8e01dca41002 | 416 | vj_uncompress_err(struct vjcompress *comp) |
donatien | 0:8e01dca41002 | 417 | { |
donatien | 0:8e01dca41002 | 418 | comp->flags |= VJF_TOSS; |
donatien | 0:8e01dca41002 | 419 | INCR(vjs_errorin); |
donatien | 0:8e01dca41002 | 420 | } |
donatien | 0:8e01dca41002 | 421 | |
donatien | 0:8e01dca41002 | 422 | /* |
donatien | 0:8e01dca41002 | 423 | * "Uncompress" a packet of type TYPE_UNCOMPRESSED_TCP. |
donatien | 0:8e01dca41002 | 424 | * Return 0 on success, -1 on failure. |
donatien | 0:8e01dca41002 | 425 | */ |
donatien | 0:8e01dca41002 | 426 | int |
donatien | 0:8e01dca41002 | 427 | vj_uncompress_uncomp(struct pbuf *nb, struct vjcompress *comp) |
donatien | 0:8e01dca41002 | 428 | { |
donatien | 0:8e01dca41002 | 429 | register u_int hlen; |
donatien | 0:8e01dca41002 | 430 | register struct cstate *cs; |
donatien | 0:8e01dca41002 | 431 | register struct ip_hdr *ip; |
donatien | 0:8e01dca41002 | 432 | |
donatien | 0:8e01dca41002 | 433 | ip = (struct ip_hdr *)nb->payload; |
donatien | 0:8e01dca41002 | 434 | hlen = IPH_HL(ip) << 2; |
donatien | 0:8e01dca41002 | 435 | if (IPH_PROTO(ip) >= MAX_SLOTS |
donatien | 0:8e01dca41002 | 436 | || hlen + sizeof(struct tcp_hdr) > nb->len |
donatien | 0:8e01dca41002 | 437 | || (hlen += TCPH_OFFSET(((struct tcp_hdr *)&((char *)ip)[hlen])) << 2) |
donatien | 0:8e01dca41002 | 438 | > nb->len |
donatien | 0:8e01dca41002 | 439 | || hlen > MAX_HDR) { |
donatien | 0:8e01dca41002 | 440 | PPPDEBUG(LOG_INFO, ("vj_uncompress_uncomp: bad cid=%d, hlen=%d buflen=%d\n", |
donatien | 0:8e01dca41002 | 441 | IPH_PROTO(ip), hlen, nb->len)); |
donatien | 0:8e01dca41002 | 442 | comp->flags |= VJF_TOSS; |
donatien | 0:8e01dca41002 | 443 | INCR(vjs_errorin); |
donatien | 0:8e01dca41002 | 444 | return -1; |
donatien | 0:8e01dca41002 | 445 | } |
donatien | 0:8e01dca41002 | 446 | cs = &comp->rstate[comp->last_recv = IPH_PROTO(ip)]; |
donatien | 0:8e01dca41002 | 447 | comp->flags &=~ VJF_TOSS; |
donatien | 0:8e01dca41002 | 448 | IPH_PROTO_SET(ip, IP_PROTO_TCP); |
donatien | 0:8e01dca41002 | 449 | BCOPY(ip, &cs->cs_ip, hlen); |
donatien | 0:8e01dca41002 | 450 | cs->cs_hlen = (u_short)hlen; |
donatien | 0:8e01dca41002 | 451 | INCR(vjs_uncompressedin); |
donatien | 0:8e01dca41002 | 452 | return 0; |
donatien | 0:8e01dca41002 | 453 | } |
donatien | 0:8e01dca41002 | 454 | |
donatien | 0:8e01dca41002 | 455 | /* |
donatien | 0:8e01dca41002 | 456 | * Uncompress a packet of type TYPE_COMPRESSED_TCP. |
donatien | 0:8e01dca41002 | 457 | * The packet is composed of a buffer chain and the first buffer |
donatien | 0:8e01dca41002 | 458 | * must contain an accurate chain length. |
donatien | 0:8e01dca41002 | 459 | * The first buffer must include the entire compressed TCP/IP header. |
donatien | 0:8e01dca41002 | 460 | * This procedure replaces the compressed header with the uncompressed |
donatien | 0:8e01dca41002 | 461 | * header and returns the length of the VJ header. |
donatien | 0:8e01dca41002 | 462 | */ |
donatien | 0:8e01dca41002 | 463 | int |
donatien | 0:8e01dca41002 | 464 | vj_uncompress_tcp(struct pbuf **nb, struct vjcompress *comp) |
donatien | 0:8e01dca41002 | 465 | { |
donatien | 0:8e01dca41002 | 466 | u_char *cp; |
donatien | 0:8e01dca41002 | 467 | struct tcp_hdr *th; |
donatien | 0:8e01dca41002 | 468 | struct cstate *cs; |
donatien | 0:8e01dca41002 | 469 | u_short *bp; |
donatien | 0:8e01dca41002 | 470 | struct pbuf *n0 = *nb; |
donatien | 0:8e01dca41002 | 471 | u32_t tmp; |
donatien | 0:8e01dca41002 | 472 | u_int vjlen, hlen, changes; |
donatien | 0:8e01dca41002 | 473 | |
donatien | 0:8e01dca41002 | 474 | INCR(vjs_compressedin); |
donatien | 0:8e01dca41002 | 475 | cp = (u_char *)n0->payload; |
donatien | 0:8e01dca41002 | 476 | changes = *cp++; |
donatien | 0:8e01dca41002 | 477 | if (changes & NEW_C) { |
donatien | 0:8e01dca41002 | 478 | /* |
donatien | 0:8e01dca41002 | 479 | * Make sure the state index is in range, then grab the state. |
donatien | 0:8e01dca41002 | 480 | * If we have a good state index, clear the 'discard' flag. |
donatien | 0:8e01dca41002 | 481 | */ |
donatien | 0:8e01dca41002 | 482 | if (*cp >= MAX_SLOTS) { |
donatien | 0:8e01dca41002 | 483 | PPPDEBUG(LOG_INFO, ("vj_uncompress_tcp: bad cid=%d\n", *cp)); |
donatien | 0:8e01dca41002 | 484 | goto bad; |
donatien | 0:8e01dca41002 | 485 | } |
donatien | 0:8e01dca41002 | 486 | |
donatien | 0:8e01dca41002 | 487 | comp->flags &=~ VJF_TOSS; |
donatien | 0:8e01dca41002 | 488 | comp->last_recv = *cp++; |
donatien | 0:8e01dca41002 | 489 | } else { |
donatien | 0:8e01dca41002 | 490 | /* |
donatien | 0:8e01dca41002 | 491 | * this packet has an implicit state index. If we've |
donatien | 0:8e01dca41002 | 492 | * had a line error since the last time we got an |
donatien | 0:8e01dca41002 | 493 | * explicit state index, we have to toss the packet. |
donatien | 0:8e01dca41002 | 494 | */ |
donatien | 0:8e01dca41002 | 495 | if (comp->flags & VJF_TOSS) { |
donatien | 0:8e01dca41002 | 496 | PPPDEBUG(LOG_INFO, ("vj_uncompress_tcp: tossing\n")); |
donatien | 0:8e01dca41002 | 497 | INCR(vjs_tossed); |
donatien | 0:8e01dca41002 | 498 | return (-1); |
donatien | 0:8e01dca41002 | 499 | } |
donatien | 0:8e01dca41002 | 500 | } |
donatien | 0:8e01dca41002 | 501 | cs = &comp->rstate[comp->last_recv]; |
donatien | 0:8e01dca41002 | 502 | hlen = IPH_HL(&cs->cs_ip) << 2; |
donatien | 0:8e01dca41002 | 503 | th = (struct tcp_hdr *)&((u_char *)&cs->cs_ip)[hlen]; |
donatien | 0:8e01dca41002 | 504 | th->chksum = htons((*cp << 8) | cp[1]); |
donatien | 0:8e01dca41002 | 505 | cp += 2; |
donatien | 0:8e01dca41002 | 506 | if (changes & TCP_PUSH_BIT) { |
donatien | 0:8e01dca41002 | 507 | TCPH_SET_FLAG(th, TCP_PSH); |
donatien | 0:8e01dca41002 | 508 | } else { |
donatien | 0:8e01dca41002 | 509 | TCPH_UNSET_FLAG(th, TCP_PSH); |
donatien | 0:8e01dca41002 | 510 | } |
donatien | 0:8e01dca41002 | 511 | |
donatien | 0:8e01dca41002 | 512 | switch (changes & SPECIALS_MASK) { |
donatien | 0:8e01dca41002 | 513 | case SPECIAL_I: |
donatien | 0:8e01dca41002 | 514 | { |
donatien | 0:8e01dca41002 | 515 | register u32_t i = ntohs(IPH_LEN(&cs->cs_ip)) - cs->cs_hlen; |
donatien | 0:8e01dca41002 | 516 | /* some compilers can't nest inline assembler.. */ |
donatien | 0:8e01dca41002 | 517 | tmp = ntohl(th->ackno) + i; |
donatien | 0:8e01dca41002 | 518 | th->ackno = htonl(tmp); |
donatien | 0:8e01dca41002 | 519 | tmp = ntohl(th->seqno) + i; |
donatien | 0:8e01dca41002 | 520 | th->seqno = htonl(tmp); |
donatien | 0:8e01dca41002 | 521 | } |
donatien | 0:8e01dca41002 | 522 | break; |
donatien | 0:8e01dca41002 | 523 | |
donatien | 0:8e01dca41002 | 524 | case SPECIAL_D: |
donatien | 0:8e01dca41002 | 525 | /* some compilers can't nest inline assembler.. */ |
donatien | 0:8e01dca41002 | 526 | tmp = ntohl(th->seqno) + ntohs(IPH_LEN(&cs->cs_ip)) - cs->cs_hlen; |
donatien | 0:8e01dca41002 | 527 | th->seqno = htonl(tmp); |
donatien | 0:8e01dca41002 | 528 | break; |
donatien | 0:8e01dca41002 | 529 | |
donatien | 0:8e01dca41002 | 530 | default: |
donatien | 0:8e01dca41002 | 531 | if (changes & NEW_U) { |
donatien | 0:8e01dca41002 | 532 | TCPH_SET_FLAG(th, TCP_URG); |
donatien | 0:8e01dca41002 | 533 | DECODEU(th->urgp); |
donatien | 0:8e01dca41002 | 534 | } else { |
donatien | 0:8e01dca41002 | 535 | TCPH_UNSET_FLAG(th, TCP_URG); |
donatien | 0:8e01dca41002 | 536 | } |
donatien | 0:8e01dca41002 | 537 | if (changes & NEW_W) { |
donatien | 0:8e01dca41002 | 538 | DECODES(th->wnd); |
donatien | 0:8e01dca41002 | 539 | } |
donatien | 0:8e01dca41002 | 540 | if (changes & NEW_A) { |
donatien | 0:8e01dca41002 | 541 | DECODEL(th->ackno); |
donatien | 0:8e01dca41002 | 542 | } |
donatien | 0:8e01dca41002 | 543 | if (changes & NEW_S) { |
donatien | 0:8e01dca41002 | 544 | DECODEL(th->seqno); |
donatien | 0:8e01dca41002 | 545 | } |
donatien | 0:8e01dca41002 | 546 | break; |
donatien | 0:8e01dca41002 | 547 | } |
donatien | 0:8e01dca41002 | 548 | if (changes & NEW_I) { |
donatien | 0:8e01dca41002 | 549 | DECODES(cs->cs_ip._id); |
donatien | 0:8e01dca41002 | 550 | } else { |
donatien | 0:8e01dca41002 | 551 | IPH_ID_SET(&cs->cs_ip, ntohs(IPH_ID(&cs->cs_ip)) + 1); |
donatien | 0:8e01dca41002 | 552 | IPH_ID_SET(&cs->cs_ip, htons(IPH_ID(&cs->cs_ip))); |
donatien | 0:8e01dca41002 | 553 | } |
donatien | 0:8e01dca41002 | 554 | |
donatien | 0:8e01dca41002 | 555 | /* |
donatien | 0:8e01dca41002 | 556 | * At this point, cp points to the first byte of data in the |
donatien | 0:8e01dca41002 | 557 | * packet. Fill in the IP total length and update the IP |
donatien | 0:8e01dca41002 | 558 | * header checksum. |
donatien | 0:8e01dca41002 | 559 | */ |
donatien | 0:8e01dca41002 | 560 | vjlen = (u_short)(cp - (u_char*)n0->payload); |
donatien | 0:8e01dca41002 | 561 | if (n0->len < vjlen) { |
donatien | 0:8e01dca41002 | 562 | /* |
donatien | 0:8e01dca41002 | 563 | * We must have dropped some characters (crc should detect |
donatien | 0:8e01dca41002 | 564 | * this but the old slip framing won't) |
donatien | 0:8e01dca41002 | 565 | */ |
donatien | 0:8e01dca41002 | 566 | PPPDEBUG(LOG_INFO, ("vj_uncompress_tcp: head buffer %d too short %d\n", |
donatien | 0:8e01dca41002 | 567 | n0->len, vjlen)); |
donatien | 0:8e01dca41002 | 568 | goto bad; |
donatien | 0:8e01dca41002 | 569 | } |
donatien | 0:8e01dca41002 | 570 | |
donatien | 0:8e01dca41002 | 571 | #if BYTE_ORDER == LITTLE_ENDIAN |
donatien | 0:8e01dca41002 | 572 | tmp = n0->tot_len - vjlen + cs->cs_hlen; |
donatien | 0:8e01dca41002 | 573 | IPH_LEN_SET(&cs->cs_ip, htons((u_short)tmp)); |
donatien | 0:8e01dca41002 | 574 | #else |
donatien | 0:8e01dca41002 | 575 | IPH_LEN_SET(&cs->cs_ip, htons(n0->tot_len - vjlen + cs->cs_hlen)); |
donatien | 0:8e01dca41002 | 576 | #endif |
donatien | 0:8e01dca41002 | 577 | |
donatien | 0:8e01dca41002 | 578 | /* recompute the ip header checksum */ |
donatien | 0:8e01dca41002 | 579 | bp = (u_short *) &cs->cs_ip; |
donatien | 0:8e01dca41002 | 580 | IPH_CHKSUM_SET(&cs->cs_ip, 0); |
donatien | 0:8e01dca41002 | 581 | for (tmp = 0; hlen > 0; hlen -= 2) { |
donatien | 0:8e01dca41002 | 582 | tmp += *bp++; |
donatien | 0:8e01dca41002 | 583 | } |
donatien | 0:8e01dca41002 | 584 | tmp = (tmp & 0xffff) + (tmp >> 16); |
donatien | 0:8e01dca41002 | 585 | tmp = (tmp & 0xffff) + (tmp >> 16); |
donatien | 0:8e01dca41002 | 586 | IPH_CHKSUM_SET(&cs->cs_ip, (u_short)(~tmp)); |
donatien | 0:8e01dca41002 | 587 | |
donatien | 0:8e01dca41002 | 588 | /* Remove the compressed header and prepend the uncompressed header. */ |
donatien | 0:8e01dca41002 | 589 | if(pbuf_header(n0, -((s16_t)(vjlen)))) { |
donatien | 0:8e01dca41002 | 590 | /* Can we cope with this failing? Just assert for now */ |
donatien | 0:8e01dca41002 | 591 | LWIP_ASSERT("pbuf_header failed\n", 0); |
donatien | 0:8e01dca41002 | 592 | goto bad; |
donatien | 0:8e01dca41002 | 593 | } |
donatien | 0:8e01dca41002 | 594 | |
donatien | 0:8e01dca41002 | 595 | if(LWIP_MEM_ALIGN(n0->payload) != n0->payload) { |
donatien | 0:8e01dca41002 | 596 | struct pbuf *np, *q; |
donatien | 0:8e01dca41002 | 597 | u8_t *bufptr; |
donatien | 0:8e01dca41002 | 598 | |
donatien | 0:8e01dca41002 | 599 | np = pbuf_alloc(PBUF_RAW, n0->len + cs->cs_hlen, PBUF_POOL); |
donatien | 0:8e01dca41002 | 600 | if(!np) { |
donatien | 0:8e01dca41002 | 601 | PPPDEBUG(LOG_WARNING, ("vj_uncompress_tcp: realign failed\n")); |
donatien | 0:8e01dca41002 | 602 | goto bad; |
donatien | 0:8e01dca41002 | 603 | } |
donatien | 0:8e01dca41002 | 604 | |
donatien | 0:8e01dca41002 | 605 | if(pbuf_header(np, -cs->cs_hlen)) { |
donatien | 0:8e01dca41002 | 606 | /* Can we cope with this failing? Just assert for now */ |
donatien | 0:8e01dca41002 | 607 | LWIP_ASSERT("pbuf_header failed\n", 0); |
donatien | 0:8e01dca41002 | 608 | goto bad; |
donatien | 0:8e01dca41002 | 609 | } |
donatien | 0:8e01dca41002 | 610 | |
donatien | 0:8e01dca41002 | 611 | bufptr = n0->payload; |
donatien | 0:8e01dca41002 | 612 | for(q = np; q != NULL; q = q->next) { |
donatien | 0:8e01dca41002 | 613 | MEMCPY(q->payload, bufptr, q->len); |
donatien | 0:8e01dca41002 | 614 | bufptr += q->len; |
donatien | 0:8e01dca41002 | 615 | } |
donatien | 0:8e01dca41002 | 616 | |
donatien | 0:8e01dca41002 | 617 | if(n0->next) { |
donatien | 0:8e01dca41002 | 618 | pbuf_chain(np, n0->next); |
donatien | 0:8e01dca41002 | 619 | pbuf_dechain(n0); |
donatien | 0:8e01dca41002 | 620 | } |
donatien | 0:8e01dca41002 | 621 | pbuf_free(n0); |
donatien | 0:8e01dca41002 | 622 | n0 = np; |
donatien | 0:8e01dca41002 | 623 | } |
donatien | 0:8e01dca41002 | 624 | |
donatien | 0:8e01dca41002 | 625 | if(pbuf_header(n0, cs->cs_hlen)) { |
donatien | 0:8e01dca41002 | 626 | struct pbuf *np; |
donatien | 0:8e01dca41002 | 627 | |
donatien | 0:8e01dca41002 | 628 | LWIP_ASSERT("vj_uncompress_tcp: cs->cs_hlen <= PBUF_POOL_BUFSIZE", cs->cs_hlen <= PBUF_POOL_BUFSIZE); |
donatien | 0:8e01dca41002 | 629 | np = pbuf_alloc(PBUF_RAW, cs->cs_hlen, PBUF_POOL); |
donatien | 0:8e01dca41002 | 630 | if(!np) { |
donatien | 0:8e01dca41002 | 631 | PPPDEBUG(LOG_WARNING, ("vj_uncompress_tcp: prepend failed\n")); |
donatien | 0:8e01dca41002 | 632 | goto bad; |
donatien | 0:8e01dca41002 | 633 | } |
donatien | 0:8e01dca41002 | 634 | pbuf_cat(np, n0); |
donatien | 0:8e01dca41002 | 635 | n0 = np; |
donatien | 0:8e01dca41002 | 636 | } |
donatien | 0:8e01dca41002 | 637 | LWIP_ASSERT("n0->len >= cs->cs_hlen", n0->len >= cs->cs_hlen); |
donatien | 0:8e01dca41002 | 638 | MEMCPY(n0->payload, &cs->cs_ip, cs->cs_hlen); |
donatien | 0:8e01dca41002 | 639 | |
donatien | 0:8e01dca41002 | 640 | *nb = n0; |
donatien | 0:8e01dca41002 | 641 | |
donatien | 0:8e01dca41002 | 642 | return vjlen; |
donatien | 0:8e01dca41002 | 643 | |
donatien | 0:8e01dca41002 | 644 | bad: |
donatien | 0:8e01dca41002 | 645 | comp->flags |= VJF_TOSS; |
donatien | 0:8e01dca41002 | 646 | INCR(vjs_errorin); |
donatien | 0:8e01dca41002 | 647 | return (-1); |
donatien | 0:8e01dca41002 | 648 | } |
donatien | 0:8e01dca41002 | 649 | |
donatien | 0:8e01dca41002 | 650 | #endif /* VJ_SUPPORT */ |
donatien | 0:8e01dca41002 | 651 | |
donatien | 0:8e01dca41002 | 652 | #endif /* PPP_SUPPORT */ |