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: src/usr.sbin/ppp/async.c,v 1.23.2.3 2002/09/01 02:12:22 brian Exp $ 29 * $DragonFly: src/usr.sbin/ppp/async.c,v 1.2 2003/06/17 04:30:00 dillon Exp $ 30 */ 31 32 #include <sys/types.h> 33 34 #include <string.h> 35 #include <termios.h> 36 37 #include "layer.h" 38 #include "mbuf.h" 39 #include "log.h" 40 #include "defs.h" 41 #include "timer.h" 42 #include "fsm.h" 43 #include "lqr.h" 44 #include "hdlc.h" 45 #include "lcp.h" 46 #include "proto.h" 47 #include "async.h" 48 #include "throughput.h" 49 #include "ccp.h" 50 #include "link.h" 51 #include "descriptor.h" 52 #include "physical.h" 53 54 #define MODE_HUNT 0x01 55 #define MODE_ESC 0x02 56 57 void 58 async_Init(struct async *async) 59 { 60 async_Setup(async); 61 memset(async->cfg.EscMap, '\0', sizeof async->cfg.EscMap); 62 } 63 64 void 65 async_Setup(struct async *async) 66 { 67 async->mode = MODE_HUNT; 68 async->length = 0; 69 async->my_accmap = async->his_accmap = 0xffffffff; 70 } 71 72 void 73 async_SetLinkParams(struct async *async, u_int32_t mymap, u_int32_t hismap) 74 { 75 async->my_accmap = mymap; 76 async->his_accmap = hismap | mymap; 77 } 78 79 /* 80 * Encode into async HDLC byte code 81 */ 82 static void 83 async_Encode(struct async *async, u_char **cp, u_char c, int proto) 84 { 85 u_char *wp; 86 87 wp = *cp; 88 if ((c < 0x20 && (proto == PROTO_LCP || (async->his_accmap & (1 << c)))) 89 || (c == HDLC_ESC) || (c == HDLC_SYN)) { 90 *wp++ = HDLC_ESC; 91 c ^= HDLC_XOR; 92 } 93 if (async->cfg.EscMap[32] && async->cfg.EscMap[c >> 3] & (1 << (c & 7))) { 94 *wp++ = HDLC_ESC; 95 c ^= HDLC_XOR; 96 } 97 *wp++ = c; 98 *cp = wp; 99 } 100 101 static struct mbuf * 102 async_LayerPush(struct bundle *bundle, struct link *l, struct mbuf *bp, 103 int pri, u_short *proto) 104 { 105 struct physical *p = link2physical(l); 106 u_char *cp, *sp, *ep; 107 struct mbuf *wp; 108 int cnt; 109 110 if (!p || m_length(bp) > HDLCSIZE) { 111 m_freem(bp); 112 return NULL; 113 } 114 115 cp = p->async.xbuff; 116 ep = cp + HDLCSIZE - 10; 117 wp = bp; 118 *cp++ = HDLC_SYN; 119 while (wp) { 120 sp = MBUF_CTOP(wp); 121 for (cnt = wp->m_len; cnt > 0; cnt--) { 122 async_Encode(&p->async, &cp, *sp++, *proto); 123 if (cp >= ep) { 124 m_freem(bp); 125 return NULL; 126 } 127 } 128 wp = wp->m_next; 129 } 130 *cp++ = HDLC_SYN; 131 132 cnt = cp - p->async.xbuff; 133 m_freem(bp); 134 bp = m_get(cnt, MB_ASYNCOUT); 135 memcpy(MBUF_CTOP(bp), p->async.xbuff, cnt); 136 log_DumpBp(LogASYNC, "Write", bp); 137 138 return bp; 139 } 140 141 static struct mbuf * 142 async_Decode(struct async *async, u_char c) 143 { 144 struct mbuf *bp; 145 146 if ((async->mode & MODE_HUNT) && c != HDLC_SYN) 147 return NULL; 148 149 switch (c) { 150 case HDLC_SYN: 151 async->mode &= ~MODE_HUNT; 152 if (async->length) { /* packet is ready. */ 153 bp = m_get(async->length, MB_ASYNCIN); 154 mbuf_Write(bp, async->hbuff, async->length); 155 async->length = 0; 156 return bp; 157 } 158 break; 159 case HDLC_ESC: 160 if (!(async->mode & MODE_ESC)) { 161 async->mode |= MODE_ESC; 162 break; 163 } 164 /* FALLTHROUGH */ 165 default: 166 if (async->length >= HDLCSIZE) { 167 /* packet is too large, discard it */ 168 log_Printf(LogWARN, "Packet too large (%d), discarding.\n", 169 async->length); 170 async->length = 0; 171 async->mode = MODE_HUNT; 172 break; 173 } 174 if (async->mode & MODE_ESC) { 175 c ^= HDLC_XOR; 176 async->mode &= ~MODE_ESC; 177 } 178 async->hbuff[async->length++] = c; 179 break; 180 } 181 return NULL; 182 } 183 184 static struct mbuf * 185 async_LayerPull(struct bundle *b, struct link *l, struct mbuf *bp, 186 u_short *proto) 187 { 188 struct mbuf *nbp, **last; 189 struct physical *p = link2physical(l); 190 u_char *ch; 191 size_t cnt; 192 193 if (!p) { 194 log_Printf(LogERROR, "Can't Pull an async packet from a logical link\n"); 195 return bp; 196 } 197 198 last = &nbp; 199 200 log_DumpBp(LogASYNC, "Read", bp); 201 while (bp) { 202 ch = MBUF_CTOP(bp); 203 for (cnt = bp->m_len; cnt; cnt--) { 204 *last = async_Decode(&p->async, *ch++); 205 if (*last != NULL) 206 last = &(*last)->m_nextpkt; 207 } 208 bp = m_free(bp); 209 } 210 211 return nbp; 212 } 213 214 struct layer asynclayer = 215 { LAYER_ASYNC, "async", async_LayerPush, async_LayerPull }; 216