1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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/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 *b __unused, struct link *l, struct mbuf *bp, 103 int pri __unused, u_short *proto) 104 { 105 struct physical *p = link2physical(l); 106 u_char *cp, *sp, *ep; 107 struct mbuf *wp; 108 size_t oldcnt; 109 size_t cnt; 110 111 if (!p || m_length(bp) > HDLCSIZE) { 112 m_freem(bp); 113 return NULL; 114 } 115 116 oldcnt = m_length(bp); 117 118 cp = p->async.xbuff; 119 ep = cp + HDLCSIZE - 10; 120 wp = bp; 121 *cp++ = HDLC_SYN; 122 while (wp) { 123 sp = MBUF_CTOP(wp); 124 for (cnt = wp->m_len; cnt > 0; cnt--) { 125 async_Encode(&p->async, &cp, *sp++, *proto); 126 if (cp >= ep) { 127 m_freem(bp); 128 return NULL; 129 } 130 } 131 wp = wp->m_next; 132 } 133 *cp++ = HDLC_SYN; 134 135 cnt = cp - p->async.xbuff; 136 m_freem(bp); 137 bp = m_get(cnt, MB_ASYNCOUT); 138 memcpy(MBUF_CTOP(bp), p->async.xbuff, cnt); 139 bp->priv = cnt - oldcnt; 140 log_DumpBp(LogASYNC, "Write", bp); 141 142 return bp; 143 } 144 145 static struct mbuf * 146 async_Decode(struct async *async, u_char c) 147 { 148 struct mbuf *bp; 149 150 if ((async->mode & MODE_HUNT) && c != HDLC_SYN) 151 return NULL; 152 153 switch (c) { 154 case HDLC_SYN: 155 async->mode &= ~MODE_HUNT; 156 if (async->length) { /* packet is ready. */ 157 bp = m_get(async->length, MB_ASYNCIN); 158 mbuf_Write(bp, async->hbuff, async->length); 159 async->length = 0; 160 return bp; 161 } 162 break; 163 case HDLC_ESC: 164 if (!(async->mode & MODE_ESC)) { 165 async->mode |= MODE_ESC; 166 break; 167 } 168 /* FALLTHROUGH */ 169 default: 170 if (async->length >= HDLCSIZE) { 171 /* packet is too large, discard it */ 172 log_Printf(LogWARN, "Packet too large (%d), discarding.\n", 173 async->length); 174 async->length = 0; 175 async->mode = MODE_HUNT; 176 break; 177 } 178 if (async->mode & MODE_ESC) { 179 c ^= HDLC_XOR; 180 async->mode &= ~MODE_ESC; 181 } 182 async->hbuff[async->length++] = c; 183 break; 184 } 185 return NULL; 186 } 187 188 static struct mbuf * 189 async_LayerPull(struct bundle *b __unused, struct link *l, struct mbuf *bp, 190 u_short *proto __unused) 191 { 192 struct mbuf *nbp, **last; 193 struct physical *p = link2physical(l); 194 u_char *ch; 195 size_t cnt; 196 197 if (!p) { 198 log_Printf(LogERROR, "Can't Pull an async packet from a logical link\n"); 199 return bp; 200 } 201 202 last = &nbp; 203 204 log_DumpBp(LogASYNC, "Read", bp); 205 while (bp) { 206 ch = MBUF_CTOP(bp); 207 for (cnt = bp->m_len; cnt; cnt--) { 208 *last = async_Decode(&p->async, *ch++); 209 if (*last != NULL) 210 last = &(*last)->m_nextpkt; 211 } 212 bp = m_free(bp); 213 } 214 215 return nbp; 216 } 217 218 struct layer asynclayer = 219 { LAYER_ASYNC, "async", async_LayerPush, async_LayerPull }; 220