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->mode = MODE_HUNT; 60 async->length = 0; 61 async->my_accmap = async->his_accmap = 0xffffffff; 62 memset(async->cfg.EscMap, '\0', sizeof async->cfg.EscMap); 63 } 64 65 void 66 async_SetLinkParams(struct async *async, struct lcp *lcp) 67 { 68 async->my_accmap = lcp->want_accmap; 69 async->his_accmap = lcp->his_accmap | lcp->want_accmap; 70 } 71 72 /* 73 * Encode into async HDLC byte code 74 */ 75 static void 76 async_Encode(struct async *async, u_char **cp, u_char c, int proto) 77 { 78 u_char *wp; 79 80 wp = *cp; 81 if ((c < 0x20 && (proto == PROTO_LCP || (async->his_accmap & (1 << c)))) 82 || (c == HDLC_ESC) || (c == HDLC_SYN)) { 83 *wp++ = HDLC_ESC; 84 c ^= HDLC_XOR; 85 } 86 if (async->cfg.EscMap[32] && async->cfg.EscMap[c >> 3] & (1 << (c & 7))) { 87 *wp++ = HDLC_ESC; 88 c ^= HDLC_XOR; 89 } 90 *wp++ = c; 91 *cp = wp; 92 } 93 94 static struct mbuf * 95 async_LayerPush(struct bundle *bundle, struct link *l, struct mbuf *bp, 96 int pri, u_short *proto) 97 { 98 struct physical *p = link2physical(l); 99 u_char *cp, *sp, *ep; 100 struct mbuf *wp; 101 int cnt; 102 103 if (!p || m_length(bp) > HDLCSIZE) { 104 m_freem(bp); 105 return NULL; 106 } 107 108 cp = p->async.xbuff; 109 ep = cp + HDLCSIZE - 10; 110 wp = bp; 111 *cp++ = HDLC_SYN; 112 while (wp) { 113 sp = MBUF_CTOP(wp); 114 for (cnt = wp->m_len; cnt > 0; cnt--) { 115 async_Encode(&p->async, &cp, *sp++, *proto); 116 if (cp >= ep) { 117 m_freem(bp); 118 return NULL; 119 } 120 } 121 wp = wp->m_next; 122 } 123 *cp++ = HDLC_SYN; 124 125 cnt = cp - p->async.xbuff; 126 m_freem(bp); 127 bp = m_get(cnt, MB_ASYNCOUT); 128 memcpy(MBUF_CTOP(bp), p->async.xbuff, cnt); 129 log_DumpBp(LogASYNC, "Write", bp); 130 131 return bp; 132 } 133 134 static struct mbuf * 135 async_Decode(struct async *async, u_char c) 136 { 137 struct mbuf *bp; 138 139 if ((async->mode & MODE_HUNT) && c != HDLC_SYN) 140 return NULL; 141 142 switch (c) { 143 case HDLC_SYN: 144 async->mode &= ~MODE_HUNT; 145 if (async->length) { /* packet is ready. */ 146 bp = m_get(async->length, MB_ASYNCIN); 147 mbuf_Write(bp, async->hbuff, async->length); 148 async->length = 0; 149 return bp; 150 } 151 break; 152 case HDLC_ESC: 153 if (!(async->mode & MODE_ESC)) { 154 async->mode |= MODE_ESC; 155 break; 156 } 157 /* Fall into ... */ 158 default: 159 if (async->length >= HDLCSIZE) { 160 /* packet is too large, discard it */ 161 log_Printf(LogWARN, "Packet too large (%d), discarding.\n", 162 async->length); 163 async->length = 0; 164 async->mode = MODE_HUNT; 165 break; 166 } 167 if (async->mode & MODE_ESC) { 168 c ^= HDLC_XOR; 169 async->mode &= ~MODE_ESC; 170 } 171 async->hbuff[async->length++] = c; 172 break; 173 } 174 return NULL; 175 } 176 177 static struct mbuf * 178 async_LayerPull(struct bundle *b, struct link *l, struct mbuf *bp, 179 u_short *proto) 180 { 181 struct mbuf *nbp, **last; 182 struct physical *p = link2physical(l); 183 u_char *ch; 184 size_t cnt; 185 186 if (!p) { 187 log_Printf(LogERROR, "Can't Pull an async packet from a logical link\n"); 188 return bp; 189 } 190 191 last = &nbp; 192 193 log_DumpBp(LogASYNC, "Read", bp); 194 while (bp) { 195 ch = MBUF_CTOP(bp); 196 for (cnt = bp->m_len; cnt; cnt--) { 197 *last = async_Decode(&p->async, *ch++); 198 if (*last != NULL) 199 last = &(*last)->m_nextpkt; 200 } 201 bp = m_free(bp); 202 } 203 204 return nbp; 205 } 206 207 struct layer asynclayer = 208 { LAYER_ASYNC, "async", async_LayerPush, async_LayerPull }; 209