async.c revision 37019
1102166Stjr/* 2102166Stjr * PPP Async HDLC Module 3102166Stjr * 4102166Stjr * Written by Toshiharu OHNO (tony-o@iij.ad.jp) 5102166Stjr * 6102166Stjr * Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd. 7102166Stjr * 8102166Stjr * Redistribution and use in source and binary forms are permitted 9102166Stjr * provided that the above copyright notice and this paragraph are 10102166Stjr * duplicated in all such forms and that any documentation, 11102166Stjr * advertising materials, and other materials related to such 12102166Stjr * distribution and use acknowledge that the software was developed 13102166Stjr * by the Internet Initiative Japan, Inc. The name of the 14102166Stjr * IIJ may not be used to endorse or promote products derived 15102166Stjr * from this software without specific prior written permission. 16102166Stjr * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 17102166Stjr * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 18102166Stjr * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 19102166Stjr * 20102166Stjr * $Id: async.c,v 1.16 1998/05/21 21:43:55 brian Exp $ 21102166Stjr * 22102166Stjr */ 23102166Stjr#include <sys/types.h> 24102166Stjr 25102166Stjr#include <string.h> 26107706Sru#include <termios.h> 27107706Sru 28102166Stjr#include "mbuf.h" 29102166Stjr#include "log.h" 30102166Stjr#include "defs.h" 31102166Stjr#include "timer.h" 32102166Stjr#include "fsm.h" 33102166Stjr#include "lqr.h" 34102166Stjr#include "hdlc.h" 35102166Stjr#include "lcp.h" 36102166Stjr#include "lcpproto.h" 37102166Stjr#include "async.h" 38102166Stjr#include "throughput.h" 39102166Stjr#include "ccp.h" 40102166Stjr#include "link.h" 41102166Stjr#include "descriptor.h" 42102166Stjr#include "physical.h" 43102166Stjr 44102166Stjr#define MODE_HUNT 0x01 45102166Stjr#define MODE_ESC 0x02 46102166Stjr 47102166Stjrvoid 48102166Stjrasync_Init(struct async *async) 49102166Stjr{ 50102166Stjr async->mode = MODE_HUNT; 51102166Stjr async->length = 0; 52102166Stjr async->my_accmap = async->his_accmap = 0xffffffff; 53107706Sru memset(async->cfg.EscMap, '\0', sizeof async->cfg.EscMap); 54102166Stjr} 55102166Stjr 56102166Stjrvoid 57102166Stjrasync_SetLinkParams(struct async *async, struct lcp *lcp) 58102166Stjr{ 59102166Stjr async->my_accmap = lcp->want_accmap; 60102166Stjr async->his_accmap = lcp->his_accmap; 61102166Stjr} 62102166Stjr 63/* 64 * Encode into async HDLC byte code if necessary 65 */ 66static void 67HdlcPutByte(struct async *async, u_char **cp, u_char c, int proto) 68{ 69 u_char *wp; 70 71 wp = *cp; 72 if ((c < 0x20 && (proto == PROTO_LCP || (async->his_accmap & (1 << c)))) 73 || (c == HDLC_ESC) || (c == HDLC_SYN)) { 74 *wp++ = HDLC_ESC; 75 c ^= HDLC_XOR; 76 } 77 if (async->cfg.EscMap[32] && async->cfg.EscMap[c >> 3] & (1 << (c & 7))) { 78 *wp++ = HDLC_ESC; 79 c ^= HDLC_XOR; 80 } 81 *wp++ = c; 82 *cp = wp; 83} 84 85void 86async_Output(int pri, struct mbuf *bp, int proto, struct physical *physical) 87{ 88 u_char *cp, *sp, *ep; 89 struct mbuf *wp; 90 int cnt; 91 92 if (mbuf_Length(bp) > HDLCSIZE) { 93 mbuf_Free(bp); 94 return; 95 } 96 cp = physical->async.xbuff; 97 ep = cp + HDLCSIZE - 10; 98 wp = bp; 99 *cp++ = HDLC_SYN; 100 while (wp) { 101 sp = MBUF_CTOP(wp); 102 for (cnt = wp->cnt; cnt > 0; cnt--) { 103 HdlcPutByte(&physical->async, &cp, *sp++, proto); 104 if (cp >= ep) { 105 mbuf_Free(bp); 106 return; 107 } 108 } 109 wp = wp->next; 110 } 111 *cp++ = HDLC_SYN; 112 113 cnt = cp - physical->async.xbuff; 114 log_DumpBuff(LogASYNC, "WriteModem", physical->async.xbuff, cnt); 115 link_Write(&physical->link, pri, (char *)physical->async.xbuff, cnt); 116 link_AddOutOctets(&physical->link, cnt); 117 mbuf_Free(bp); 118} 119 120static struct mbuf * 121async_Decode(struct async *async, u_char c) 122{ 123 struct mbuf *bp; 124 125 if ((async->mode & MODE_HUNT) && c != HDLC_SYN) 126 return NULL; 127 128 switch (c) { 129 case HDLC_SYN: 130 async->mode &= ~MODE_HUNT; 131 if (async->length) { /* packet is ready. */ 132 bp = mbuf_Alloc(async->length, MB_ASYNC); 133 mbuf_Write(bp, async->hbuff, async->length); 134 async->length = 0; 135 return bp; 136 } 137 break; 138 case HDLC_ESC: 139 if (!(async->mode & MODE_ESC)) { 140 async->mode |= MODE_ESC; 141 break; 142 } 143 /* Fall into ... */ 144 default: 145 if (async->length >= HDLCSIZE) { 146 /* packet is too large, discard it */ 147 log_Printf(LogWARN, "Packet too large (%d), discarding.\n", 148 async->length); 149 async->length = 0; 150 async->mode = MODE_HUNT; 151 break; 152 } 153 if (async->mode & MODE_ESC) { 154 c ^= HDLC_XOR; 155 async->mode &= ~MODE_ESC; 156 } 157 async->hbuff[async->length++] = c; 158 break; 159 } 160 return NULL; 161} 162 163void 164async_Input(struct bundle *bundle, u_char *buff, int cnt, 165 struct physical *physical) 166{ 167 struct mbuf *bp; 168 169 link_AddInOctets(&physical->link, cnt); 170 171 if (physical_IsSync(physical)) { 172 bp = mbuf_Alloc(cnt, MB_ASYNC); 173 memcpy(MBUF_CTOP(bp), buff, cnt); 174 bp->cnt = cnt; 175 hdlc_Input(bundle, bp, physical); 176 } else { 177 while (cnt > 0) { 178 bp = async_Decode(&physical->async, *buff++); 179 if (bp) 180 hdlc_Input(bundle, bp, physical); 181 cnt--; 182 } 183 } 184} 185