1 /*- 2 * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org> 3 * based on work by Toshiharu OHNO <tony-o@iij.ad.jp> 4 * Internet Initiative Japan, Inc (IIJ) 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #include <sys/types.h> 32 33 #include <string.h> 34 #include <termios.h> 35 36 #include "layer.h" 37 #include "mbuf.h" 38 #include "log.h" 39 #include "defs.h" 40 #include "timer.h" 41 #include "fsm.h" 42 #include "lqr.h" 43 #include "hdlc.h" 44 #include "lcp.h" 45 #include "proto.h" 46 #include "async.h" 47 #include "throughput.h" 48 #include "ccp.h" 49 #include "link.h" 50 #include "descriptor.h" 51 #include "physical.h" 52 53 #define MODE_HUNT 0x01 54 #define MODE_ESC 0x02 55 56 void 57 async_Init(struct async *async) 58 { 59 async_Setup(async); 60 memset(async->cfg.EscMap, '\0', sizeof async->cfg.EscMap); 61 } 62 63 void 64 async_Setup(struct async *async) 65 { 66 async->mode = MODE_HUNT; 67 async->length = 0; 68 async->my_accmap = async->his_accmap = 0xffffffff; 69 } 70 71 void 72 async_SetLinkParams(struct async *async, struct lcp *lcp) 73 { 74 async->my_accmap = lcp->want_accmap; 75 async->his_accmap = lcp->his_accmap | lcp->want_accmap; 76 } 77 78 /* 79 * Encode into async HDLC byte code 80 */ 81 static void 82 async_Encode(struct async *async, u_char **cp, u_char c, int proto) 83 { 84 u_char *wp; 85 86 wp = *cp; 87 if ((c < 0x20 && (proto == PROTO_LCP || (async->his_accmap & (1 << c)))) 88 || (c == HDLC_ESC) || (c == HDLC_SYN)) { 89 *wp++ = HDLC_ESC; 90 c ^= HDLC_XOR; 91 } 92 if (async->cfg.EscMap[32] && async->cfg.EscMap[c >> 3] & (1 << (c & 7))) { 93 *wp++ = HDLC_ESC; 94 c ^= HDLC_XOR; 95 } 96 *wp++ = c; 97 *cp = wp; 98 } 99 100 static struct mbuf * 101 async_LayerPush(struct bundle *bundle, struct link *l, struct mbuf *bp, 102 int pri, u_short *proto) 103 { 104 struct physical *p = link2physical(l); 105 u_char *cp, *sp, *ep; 106 struct mbuf *wp; 107 int cnt; 108 109 if (!p || m_length(bp) > HDLCSIZE) { 110 m_freem(bp); 111 return NULL; 112 } 113 114 cp = p->async.xbuff; 115 ep = cp + HDLCSIZE - 10; 116 wp = bp; 117 *cp++ = HDLC_SYN; 118 while (wp) { 119 sp = MBUF_CTOP(wp); 120 for (cnt = wp->m_len; cnt > 0; cnt--) { 121 async_Encode(&p->async, &cp, *sp++, *proto); 122 if (cp >= ep) { 123 m_freem(bp); 124 return NULL; 125 } 126 } 127 wp = wp->m_next; 128 } 129 *cp++ = HDLC_SYN; 130 131 cnt = cp - p->async.xbuff; 132 m_freem(bp); 133 bp = m_get(cnt, MB_ASYNCOUT); 134 memcpy(MBUF_CTOP(bp), p->async.xbuff, cnt); 135 log_DumpBp(LogASYNC, "Write", bp); 136 137 return bp; 138 } 139 140 static struct mbuf * 141 async_Decode(struct async *async, u_char c) 142 { 143 struct mbuf *bp; 144 145 if ((async->mode & MODE_HUNT) && c != HDLC_SYN) 146 return NULL; 147 148 switch (c) { 149 case HDLC_SYN: 150 async->mode &= ~MODE_HUNT; 151 if (async->length) { /* packet is ready. */ 152 bp = m_get(async->length, MB_ASYNCIN); 153 mbuf_Write(bp, async->hbuff, async->length); 154 async->length = 0; 155 return bp; 156 } 157 break; 158 case HDLC_ESC: 159 if (!(async->mode & MODE_ESC)) { 160 async->mode |= MODE_ESC; 161 break; 162 } 163 /* Fall into ... */ 164 default: 165 if (async->length >= HDLCSIZE) { 166 /* packet is too large, discard it */ 167 log_Printf(LogWARN, "Packet too large (%d), discarding.\n", 168 async->length); 169 async->length = 0; 170 async->mode = MODE_HUNT; 171 break; 172 } 173 if (async->mode & MODE_ESC) { 174 c ^= HDLC_XOR; 175 async->mode &= ~MODE_ESC; 176 } 177 async->hbuff[async->length++] = c; 178 break; 179 } 180 return NULL; 181 } 182 183 static struct mbuf * 184 async_LayerPull(struct bundle *b, struct link *l, struct mbuf *bp, 185 u_short *proto) 186 { 187 struct mbuf *nbp, **last; 188 struct physical *p = link2physical(l); 189 u_char *ch; 190 size_t cnt; 191 192 if (!p) { 193 log_Printf(LogERROR, "Can't Pull an async packet from a logical link\n"); 194 return bp; 195 } 196 197 last = &nbp; 198 199 log_DumpBp(LogASYNC, "Read", bp); 200 while (bp) { 201 ch = MBUF_CTOP(bp); 202 for (cnt = bp->m_len; cnt; cnt--) { 203 *last = async_Decode(&p->async, *ch++); 204 if (*last != NULL) 205 last = &(*last)->m_nextpkt; 206 } 207 bp = m_free(bp); 208 } 209 210 return nbp; 211 } 212 213 struct layer asynclayer = 214 { LAYER_ASYNC, "async", async_LayerPush, async_LayerPull }; 215