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 */
29
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD: src/usr.sbin/ppp/async.c,v 1.29.26.1 2010/12/21 17:10:29 kensmith Exp $");
32
33 #include <sys/types.h>
34
35 #include <string.h>
36 #include <termios.h>
37
38 #include "layer.h"
39 #include "mbuf.h"
40 #include "log.h"
41 #include "defs.h"
42 #include "timer.h"
43 #include "fsm.h"
44 #include "lqr.h"
45 #include "hdlc.h"
46 #include "lcp.h"
47 #include "proto.h"
48 #include "async.h"
49 #include "throughput.h"
50 #include "ccp.h"
51 #include "link.h"
52 #include "descriptor.h"
53 #include "physical.h"
54
55 #define MODE_HUNT 0x01
56 #define MODE_ESC 0x02
57
58 void
async_Init(struct async * async)59 async_Init(struct async *async)
60 {
61 async_Setup(async);
62 memset(async->cfg.EscMap, '\0', sizeof async->cfg.EscMap);
63 }
64
65 void
async_Setup(struct async * async)66 async_Setup(struct async *async)
67 {
68 async->mode = MODE_HUNT;
69 async->length = 0;
70 async->my_accmap = async->his_accmap = 0xffffffff;
71 }
72
73 void
async_SetLinkParams(struct async * async,u_int32_t mymap,u_int32_t hismap)74 async_SetLinkParams(struct async *async, u_int32_t mymap, u_int32_t hismap)
75 {
76 async->my_accmap = mymap;
77 async->his_accmap = hismap | mymap;
78 }
79
80 /*
81 * Encode into async HDLC byte code
82 */
83 static void
async_Encode(struct async * async,u_char ** cp,u_char c,int proto)84 async_Encode(struct async *async, u_char **cp, u_char c, int proto)
85 {
86 u_char *wp;
87
88 wp = *cp;
89 if ((c < 0x20 && (proto == PROTO_LCP || (async->his_accmap & (1 << c))))
90 || (c == HDLC_ESC) || (c == HDLC_SYN)) {
91 *wp++ = HDLC_ESC;
92 c ^= HDLC_XOR;
93 }
94 if (async->cfg.EscMap[32] && async->cfg.EscMap[c >> 3] & (1 << (c & 7))) {
95 *wp++ = HDLC_ESC;
96 c ^= HDLC_XOR;
97 }
98 *wp++ = c;
99 *cp = wp;
100 }
101
102 static struct mbuf *
async_LayerPush(struct bundle * b __unused,struct link * l,struct mbuf * bp,int pri __unused,u_short * proto)103 async_LayerPush(struct bundle *b __unused, struct link *l, struct mbuf *bp,
104 int pri __unused, u_short *proto)
105 {
106 struct physical *p = link2physical(l);
107 u_char *cp, *sp, *ep;
108 struct mbuf *wp;
109 size_t oldcnt;
110 size_t cnt;
111
112 if (!p || m_length(bp) > HDLCSIZE) {
113 m_freem(bp);
114 return NULL;
115 }
116
117 oldcnt = m_length(bp);
118
119 cp = p->async.xbuff;
120 ep = cp + HDLCSIZE - 10;
121 wp = bp;
122 *cp++ = HDLC_SYN;
123 while (wp) {
124 sp = MBUF_CTOP(wp);
125 for (cnt = wp->m_len; cnt > 0; cnt--) {
126 async_Encode(&p->async, &cp, *sp++, *proto);
127 if (cp >= ep) {
128 m_freem(bp);
129 return NULL;
130 }
131 }
132 wp = wp->m_next;
133 }
134 *cp++ = HDLC_SYN;
135
136 cnt = cp - p->async.xbuff;
137 m_freem(bp);
138 bp = m_get(cnt, MB_ASYNCOUT);
139 memcpy(MBUF_CTOP(bp), p->async.xbuff, cnt);
140 bp->priv = cnt - oldcnt;
141 log_DumpBp(LogASYNC, "Write", bp);
142
143 return bp;
144 }
145
146 static struct mbuf *
async_Decode(struct async * async,u_char c)147 async_Decode(struct async *async, u_char c)
148 {
149 struct mbuf *bp;
150
151 if ((async->mode & MODE_HUNT) && c != HDLC_SYN)
152 return NULL;
153
154 switch (c) {
155 case HDLC_SYN:
156 async->mode &= ~MODE_HUNT;
157 if (async->length) { /* packet is ready. */
158 bp = m_get(async->length, MB_ASYNCIN);
159 mbuf_Write(bp, async->hbuff, async->length);
160 async->length = 0;
161 return bp;
162 }
163 break;
164 case HDLC_ESC:
165 if (!(async->mode & MODE_ESC)) {
166 async->mode |= MODE_ESC;
167 break;
168 }
169 /* FALLTHROUGH */
170 default:
171 if (async->length >= HDLCSIZE) {
172 /* packet is too large, discard it */
173 log_Printf(LogWARN, "Packet too large (%d), discarding.\n",
174 async->length);
175 async->length = 0;
176 async->mode = MODE_HUNT;
177 break;
178 }
179 if (async->mode & MODE_ESC) {
180 c ^= HDLC_XOR;
181 async->mode &= ~MODE_ESC;
182 }
183 async->hbuff[async->length++] = c;
184 break;
185 }
186 return NULL;
187 }
188
189 static struct mbuf *
async_LayerPull(struct bundle * b __unused,struct link * l,struct mbuf * bp,u_short * proto __unused)190 async_LayerPull(struct bundle *b __unused, struct link *l, struct mbuf *bp,
191 u_short *proto __unused)
192 {
193 struct mbuf *nbp, **last;
194 struct physical *p = link2physical(l);
195 u_char *ch;
196 size_t cnt;
197
198 if (!p) {
199 log_Printf(LogERROR, "Can't Pull an async packet from a logical link\n");
200 return bp;
201 }
202
203 last = &nbp;
204
205 log_DumpBp(LogASYNC, "Read", bp);
206 while (bp) {
207 ch = MBUF_CTOP(bp);
208 for (cnt = bp->m_len; cnt; cnt--) {
209 *last = async_Decode(&p->async, *ch++);
210 if (*last != NULL)
211 last = &(*last)->m_nextpkt;
212 }
213 bp = m_free(bp);
214 }
215
216 return nbp;
217 }
218
219 struct layer asynclayer =
220 { LAYER_ASYNC, "async", async_LayerPush, async_LayerPull };
221