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Diffstat (limited to 'src/async.c')
| -rw-r--r-- | src/async.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/src/async.c b/src/async.c new file mode 100644 index 0000000..745c52f --- /dev/null +++ b/src/async.c @@ -0,0 +1,220 @@ +/*- + * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org> + * based on work by Toshiharu OHNO <tony-o@iij.ad.jp> + * Internet Initiative Japan, Inc (IIJ) + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD: src/usr.sbin/ppp/async.c,v 1.29.26.1 2010/12/21 17:10:29 kensmith Exp $"); + +#include <sys/types.h> + +#include <string.h> +#include <termios.h> + +#include "layer.h" +#include "mbuf.h" +#include "log.h" +#include "defs.h" +#include "timer.h" +#include "fsm.h" +#include "lqr.h" +#include "hdlc.h" +#include "lcp.h" +#include "proto.h" +#include "async.h" +#include "throughput.h" +#include "ccp.h" +#include "link.h" +#include "descriptor.h" +#include "physical.h" + +#define MODE_HUNT 0x01 +#define MODE_ESC 0x02 + +void +async_Init(struct async *async) +{ + async_Setup(async); + memset(async->cfg.EscMap, '\0', sizeof async->cfg.EscMap); +} + +void +async_Setup(struct async *async) +{ + async->mode = MODE_HUNT; + async->length = 0; + async->my_accmap = async->his_accmap = 0xffffffff; +} + +void +async_SetLinkParams(struct async *async, u_int32_t mymap, u_int32_t hismap) +{ + async->my_accmap = mymap; + async->his_accmap = hismap | mymap; +} + +/* + * Encode into async HDLC byte code + */ +static void +async_Encode(struct async *async, u_char **cp, u_char c, int proto) +{ + u_char *wp; + + wp = *cp; + if ((c < 0x20 && (proto == PROTO_LCP || (async->his_accmap & (1 << c)))) + || (c == HDLC_ESC) || (c == HDLC_SYN)) { + *wp++ = HDLC_ESC; + c ^= HDLC_XOR; + } + if (async->cfg.EscMap[32] && async->cfg.EscMap[c >> 3] & (1 << (c & 7))) { + *wp++ = HDLC_ESC; + c ^= HDLC_XOR; + } + *wp++ = c; + *cp = wp; +} + +static struct mbuf * +async_LayerPush(struct bundle *b __unused, struct link *l, struct mbuf *bp, + int pri __unused, u_short *proto) +{ + struct physical *p = link2physical(l); + u_char *cp, *sp, *ep; + struct mbuf *wp; + size_t oldcnt; + size_t cnt; + + if (!p || m_length(bp) > HDLCSIZE) { + m_freem(bp); + return NULL; + } + + oldcnt = m_length(bp); + + cp = p->async.xbuff; + ep = cp + HDLCSIZE - 10; + wp = bp; + *cp++ = HDLC_SYN; + while (wp) { + sp = MBUF_CTOP(wp); + for (cnt = wp->m_len; cnt > 0; cnt--) { + async_Encode(&p->async, &cp, *sp++, *proto); + if (cp >= ep) { + m_freem(bp); + return NULL; + } + } + wp = wp->m_next; + } + *cp++ = HDLC_SYN; + + cnt = cp - p->async.xbuff; + m_freem(bp); + bp = m_get(cnt, MB_ASYNCOUT); + memcpy(MBUF_CTOP(bp), p->async.xbuff, cnt); + bp->priv = cnt - oldcnt; + log_DumpBp(LogASYNC, "Write", bp); + + return bp; +} + +static struct mbuf * +async_Decode(struct async *async, u_char c) +{ + struct mbuf *bp; + + if ((async->mode & MODE_HUNT) && c != HDLC_SYN) + return NULL; + + switch (c) { + case HDLC_SYN: + async->mode &= ~MODE_HUNT; + if (async->length) { /* packet is ready. */ + bp = m_get(async->length, MB_ASYNCIN); + mbuf_Write(bp, async->hbuff, async->length); + async->length = 0; + return bp; + } + break; + case HDLC_ESC: + if (!(async->mode & MODE_ESC)) { + async->mode |= MODE_ESC; + break; + } + /* FALLTHROUGH */ + default: + if (async->length >= HDLCSIZE) { + /* packet is too large, discard it */ + log_Printf(LogWARN, "Packet too large (%d), discarding.\n", + async->length); + async->length = 0; + async->mode = MODE_HUNT; + break; + } + if (async->mode & MODE_ESC) { + c ^= HDLC_XOR; + async->mode &= ~MODE_ESC; + } + async->hbuff[async->length++] = c; + break; + } + return NULL; +} + +static struct mbuf * +async_LayerPull(struct bundle *b __unused, struct link *l, struct mbuf *bp, + u_short *proto __unused) +{ + struct mbuf *nbp, **last; + struct physical *p = link2physical(l); + u_char *ch; + size_t cnt; + + if (!p) { + log_Printf(LogERROR, "Can't Pull an async packet from a logical link\n"); + return bp; + } + + last = &nbp; + + log_DumpBp(LogASYNC, "Read", bp); + while (bp) { + ch = MBUF_CTOP(bp); + for (cnt = bp->m_len; cnt; cnt--) { + *last = async_Decode(&p->async, *ch++); + if (*last != NULL) + last = &(*last)->m_nextpkt; + } + bp = m_free(bp); + } + + return nbp; +} + +struct layer asynclayer = + { LAYER_ASYNC, "async", async_LayerPush, async_LayerPull }; |