1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org> 5 * based on work by Toshiharu OHNO <tony-o@iij.ad.jp> 6 * Internet Initiative Japan, Inc (IIJ) 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/types.h> 36 37 #include <string.h> 38 #include <termios.h> 39 40 #include "layer.h" 41 #include "mbuf.h" 42 #include "log.h" 43 #include "defs.h" 44 #include "timer.h" 45 #include "fsm.h" 46 #include "lqr.h" 47 #include "hdlc.h" 48 #include "lcp.h" 49 #include "proto.h" 50 #include "async.h" 51 #include "throughput.h" 52 #include "ccp.h" 53 #include "link.h" 54 #include "descriptor.h" 55 #include "physical.h" 56 57 #define MODE_HUNT 0x01 58 #define MODE_ESC 0x02 59 60 void 61 async_Init(struct async *async) 62 { 63 async_Setup(async); 64 memset(async->cfg.EscMap, '\0', sizeof async->cfg.EscMap); 65 } 66 67 void 68 async_Setup(struct async *async) 69 { 70 async->mode = MODE_HUNT; 71 async->length = 0; 72 async->my_accmap = async->his_accmap = 0xffffffff; 73 } 74 75 void 76 async_SetLinkParams(struct async *async, u_int32_t mymap, u_int32_t hismap) 77 { 78 async->my_accmap = mymap; 79 async->his_accmap = hismap | mymap; 80 } 81 82 /* 83 * Encode into async HDLC byte code 84 */ 85 static void 86 async_Encode(struct async *async, u_char **cp, u_char c, int proto) 87 { 88 u_char *wp; 89 90 wp = *cp; 91 if ((c < 0x20 && (proto == PROTO_LCP || (async->his_accmap & (1 << c)))) 92 || (c == HDLC_ESC) || (c == HDLC_SYN)) { 93 *wp++ = HDLC_ESC; 94 c ^= HDLC_XOR; 95 } 96 if (async->cfg.EscMap[32] && async->cfg.EscMap[c >> 3] & (1 << (c & 7))) { 97 *wp++ = HDLC_ESC; 98 c ^= HDLC_XOR; 99 } 100 *wp++ = c; 101 *cp = wp; 102 } 103 104 static struct mbuf * 105 async_LayerPush(struct bundle *b __unused, struct link *l, struct mbuf *bp, 106 int pri __unused, u_short *proto) 107 { 108 struct physical *p = link2physical(l); 109 u_char *cp, *sp, *ep; 110 struct mbuf *wp; 111 size_t oldcnt; 112 size_t cnt; 113 114 if (!p || m_length(bp) > HDLCSIZE) { 115 m_freem(bp); 116 return NULL; 117 } 118 119 oldcnt = m_length(bp); 120 121 cp = p->async.xbuff; 122 ep = cp + HDLCSIZE - 10; 123 wp = bp; 124 *cp++ = HDLC_SYN; 125 while (wp) { 126 sp = MBUF_CTOP(wp); 127 for (cnt = wp->m_len; cnt > 0; cnt--) { 128 async_Encode(&p->async, &cp, *sp++, *proto); 129 if (cp >= ep) { 130 m_freem(bp); 131 return NULL; 132 } 133 } 134 wp = wp->m_next; 135 } 136 *cp++ = HDLC_SYN; 137 138 cnt = cp - p->async.xbuff; 139 m_freem(bp); 140 bp = m_get(cnt, MB_ASYNCOUT); 141 memcpy(MBUF_CTOP(bp), p->async.xbuff, cnt); 142 bp->priv = cnt - oldcnt; 143 log_DumpBp(LogASYNC, "Write", bp); 144 145 return bp; 146 } 147 148 static struct mbuf * 149 async_Decode(struct async *async, u_char c) 150 { 151 struct mbuf *bp; 152 153 if ((async->mode & MODE_HUNT) && c != HDLC_SYN) 154 return NULL; 155 156 switch (c) { 157 case HDLC_SYN: 158 async->mode &= ~MODE_HUNT; 159 if (async->length) { /* packet is ready. */ 160 bp = m_get(async->length, MB_ASYNCIN); 161 mbuf_Write(bp, async->hbuff, async->length); 162 async->length = 0; 163 return bp; 164 } 165 break; 166 case HDLC_ESC: 167 if (!(async->mode & MODE_ESC)) { 168 async->mode |= MODE_ESC; 169 break; 170 } 171 /* FALLTHROUGH */ 172 default: 173 if (async->length >= HDLCSIZE) { 174 /* packet is too large, discard it */ 175 log_Printf(LogWARN, "Packet too large (%d), discarding.\n", 176 async->length); 177 async->length = 0; 178 async->mode = MODE_HUNT; 179 break; 180 } 181 if (async->mode & MODE_ESC) { 182 c ^= HDLC_XOR; 183 async->mode &= ~MODE_ESC; 184 } 185 async->hbuff[async->length++] = c; 186 break; 187 } 188 return NULL; 189 } 190 191 static struct mbuf * 192 async_LayerPull(struct bundle *b __unused, struct link *l, struct mbuf *bp, 193 u_short *proto __unused) 194 { 195 struct mbuf *nbp, **last; 196 struct physical *p = link2physical(l); 197 u_char *ch; 198 size_t cnt; 199 200 if (!p) { 201 log_Printf(LogERROR, "Can't Pull an async packet from a logical link\n"); 202 return bp; 203 } 204 205 last = &nbp; 206 207 log_DumpBp(LogASYNC, "Read", bp); 208 while (bp) { 209 ch = MBUF_CTOP(bp); 210 for (cnt = bp->m_len; cnt; cnt--) { 211 *last = async_Decode(&p->async, *ch++); 212 if (*last != NULL) 213 last = &(*last)->m_nextpkt; 214 } 215 bp = m_free(bp); 216 } 217 218 return nbp; 219 } 220 221 struct layer asynclayer = 222 { LAYER_ASYNC, "async", async_LayerPush, async_LayerPull }; 223