--- /dev/null
+/*
+ * ppp_ahdlc.c - STREAMS module for doing PPP asynchronous HDLC.
+ *
+ * Copyright (c) 1994 The Australian National University.
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation is hereby granted, provided that the above copyright
+ * notice appears in all copies. This software is provided without any
+ * warranty, express or implied. The Australian National University
+ * makes no representations about the suitability of this software for
+ * any purpose.
+ *
+ * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
+ * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
+ * THE AUSTRALIAN NATIONAL UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
+ * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
+ * OR MODIFICATIONS.
+ *
+ * $Id: ppp_ahdlc.c,v 1.1 1995/12/11 05:06:42 paulus Exp $
+ */
+
+/*
+ * This file is used under Solaris 2, SVR4, SunOS 4, and OSF/1.
+ */
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/stream.h>
+#include <sys/errno.h>
+
+#ifdef SVR4
+#include <sys/conf.h>
+#include <sys/kmem.h>
+#include <sys/cmn_err.h>
+#include <sys/ddi.h>
+#else
+#include <sys/user.h>
+#endif /* SVR4 */
+
+#include <net/ppp_defs.h>
+#include <net/pppio.h>
+#include "ppp_mod.h"
+
+#define IFRAME_BSIZE 512 /* Block size to allocate for input */
+#define OFRAME_BSIZE 4096 /* Don't allocb more than this for output */
+
+MOD_OPEN_DECL(ahdlc_open);
+MOD_CLOSE_DECL(ahdlc_close);
+static int ahdlc_wput __P((queue_t *, mblk_t *));
+static int ahdlc_rput __P((queue_t *, mblk_t *));
+static void stuff_frame __P((queue_t *, mblk_t *));
+static void unstuff_chars __P((queue_t *, mblk_t *));
+static int msg_byte __P((mblk_t *, unsigned int));
+
+/* Extract byte i of message mp. */
+#define MSG_BYTE(mp, i) ((i) < (mp)->b_wptr - (mp)->b_rptr? (mp)->b_rptr[i]: \
+ msg_byte((mp), (i)))
+
+/* Is this LCP packet one we have to transmit using LCP defaults? */
+#define LCP_USE_DFLT(mp) (1 <= (code = MSG_BYTE((mp), 4)) && code <= 7)
+
+static struct module_info minfo = {
+ 0x7d23, "ppp_ahdl", 0, INFPSZ, 4096, 128
+};
+
+static struct qinit rinit = {
+ ahdlc_rput, NULL, ahdlc_open, ahdlc_close, NULL, &minfo, NULL
+};
+
+static struct qinit winit = {
+ ahdlc_wput, NULL, NULL, NULL, NULL, &minfo, NULL
+};
+
+struct streamtab ppp_ahdlcinfo = {
+ &rinit, &winit, NULL, NULL
+};
+
+int ppp_ahdlc_count;
+
+typedef struct ahdlc_state {
+ int flags;
+ mblk_t *cur_frame;
+ mblk_t *cur_blk;
+ int inlen;
+ ushort infcs;
+ u_int32_t xaccm[8];
+ u_int32_t raccm;
+ int mtu;
+ int mru;
+ int unit;
+ struct pppstat stats;
+} ahdlc_state_t;
+
+/* Values for flags */
+#define ESCAPED 0x100 /* last saw escape char on input */
+#define IFLUSH 0x200 /* flushing input due to error */
+
+/* RCV_B7_1, etc., defined in net/pppio.h, are stored in flags also. */
+#define RCV_FLAGS (RCV_B7_1|RCV_B7_0|RCV_ODDP|RCV_EVNP)
+
+/*
+ * FCS lookup table as calculated by genfcstab.
+ */
+static u_short fcstab[256] = {
+ 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
+ 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
+ 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
+ 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
+ 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
+ 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
+ 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
+ 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
+ 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
+ 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
+ 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
+ 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
+ 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
+ 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
+ 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
+ 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
+ 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
+ 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
+ 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
+ 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
+ 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
+ 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
+ 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
+ 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
+ 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
+ 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
+ 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
+ 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
+ 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
+ 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
+ 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
+ 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
+};
+
+/*
+ * STREAMS module entry points.
+ */
+MOD_OPEN(ahdlc_open)
+{
+ ahdlc_state_t *sp;
+
+ if (q->q_ptr == 0) {
+ sp = (ahdlc_state_t *) ALLOC_SLEEP(sizeof(ahdlc_state_t));
+ if (sp == 0)
+ OPEN_ERROR(ENOSR);
+ bzero((caddr_t) sp, sizeof(ahdlc_state_t));
+ q->q_ptr = (caddr_t) sp;
+ WR(q)->q_ptr = (caddr_t) sp;
+ sp->xaccm[0] = ~0;
+ sp->xaccm[3] = 0x60000000;
+ sp->mru = 1500;
+ ++ppp_ahdlc_count;
+ qprocson(q);
+ }
+ return 0;
+}
+
+MOD_CLOSE(ahdlc_close)
+{
+ ahdlc_state_t *state;
+
+ qprocsoff(q);
+ if (q->q_ptr != 0) {
+ state = (ahdlc_state_t *) q->q_ptr;
+ if (state->cur_frame != 0) {
+ freemsg(state->cur_frame);
+ state->cur_frame = 0;
+ }
+ FREE(q->q_ptr, sizeof(ahdlc_state_t));
+ --ppp_ahdlc_count;
+ }
+ return 0;
+}
+
+static int
+ahdlc_wput(q, mp)
+ queue_t *q;
+ mblk_t *mp;
+{
+ ahdlc_state_t *state;
+ struct iocblk *iop;
+ int error;
+ mblk_t *np;
+ struct ppp_stats *psp;
+
+ state = (ahdlc_state_t *) q->q_ptr;
+ switch (mp->b_datap->db_type) {
+ case M_DATA:
+ /*
+ * A data packet - do character-stuffing and FCS, and
+ * send it onwards.
+ */
+ stuff_frame(q, mp);
+ freemsg(mp);
+ break;
+
+ case M_IOCTL:
+ iop = (struct iocblk *) mp->b_rptr;
+ error = EINVAL;
+ switch (iop->ioc_cmd) {
+ case PPPIO_XACCM:
+ if (iop->ioc_count < sizeof(u_int32_t)
+ || iop->ioc_count > sizeof(ext_accm))
+ break;
+ bcopy((caddr_t)mp->b_cont->b_rptr, (caddr_t)state->xaccm,
+ iop->ioc_count);
+ state->xaccm[2] &= 0x40000000; /* don't escape 0x5e */
+ state->xaccm[3] |= 0x60000000; /* do escape 0x7d, 0x7e */
+ iop->ioc_count = 0;
+ error = 0;
+ break;
+
+ case PPPIO_RACCM:
+ if (iop->ioc_count != sizeof(u_int32_t))
+ break;
+ bcopy((caddr_t)mp->b_cont->b_rptr, (caddr_t)&state->raccm,
+ sizeof(u_int32_t));
+ iop->ioc_count = 0;
+ error = 0;
+ break;
+
+ case PPPIO_GCLEAN:
+ np = allocb(sizeof(int), BPRI_HI);
+ if (np == 0) {
+ error = ENOSR;
+ break;
+ }
+ if (mp->b_cont != 0)
+ freemsg(mp->b_cont);
+ mp->b_cont = np;
+ *(int *)np->b_wptr = state->flags & RCV_FLAGS;
+ np->b_wptr += sizeof(int);
+ iop->ioc_count = sizeof(int);
+ error = 0;
+ break;
+
+ case PPPIO_GETSTAT:
+ np = allocb(sizeof(struct ppp_stats), BPRI_HI);
+ if (np == 0) {
+ error = ENOSR;
+ break;
+ }
+ if (mp->b_cont != 0)
+ freemsg(mp->b_cont);
+ mp->b_cont = np;
+ psp = (struct ppp_stats *) np->b_wptr;
+ np->b_wptr += sizeof(struct ppp_stats);
+ bzero((caddr_t)psp, sizeof(struct ppp_stats));
+ psp->p = state->stats;
+ iop->ioc_count = sizeof(struct ppp_stats);
+ error = 0;
+ break;
+
+ case PPPIO_LASTMOD:
+ /* we knew this anyway */
+ error = 0;
+ break;
+
+ default:
+ error = -1;
+ break;
+ }
+
+ if (error < 0)
+ putnext(q, mp);
+ else if (error == 0) {
+ mp->b_datap->db_type = M_IOCACK;
+ qreply(q, mp);
+ } else {
+ mp->b_datap->db_type = M_IOCNAK;
+ iop->ioc_count = 0;
+ iop->ioc_error = error;
+ qreply(q, mp);
+ }
+ break;
+
+ case M_CTL:
+ switch (*mp->b_rptr) {
+ case PPPCTL_MTU:
+ state->mtu = ((unsigned short *)mp->b_rptr)[1];
+ freemsg(mp);
+ break;
+ case PPPCTL_MRU:
+ state->mru = ((unsigned short *)mp->b_rptr)[1];
+ freemsg(mp);
+ break;
+ case PPPCTL_UNIT:
+ state->unit = mp->b_rptr[1];
+ break;
+ default:
+ putnext(q, mp);
+ }
+ break;
+
+ default:
+ putnext(q, mp);
+ }
+ return 0;
+}
+
+static int
+ahdlc_rput(q, mp)
+ queue_t *q;
+ mblk_t *mp;
+{
+ mblk_t *np;
+ uchar_t *cp;
+ ahdlc_state_t *state;
+
+ switch (mp->b_datap->db_type) {
+ case M_DATA:
+ unstuff_chars(q, mp);
+ freemsg(mp);
+ break;
+
+ case M_HANGUP:
+ state = (ahdlc_state_t *) q->q_ptr;
+ if (state->cur_frame != 0) {
+ /* XXX would like to send this up for debugging */
+ freemsg(state->cur_frame);
+ state->cur_frame = 0;
+ state->cur_blk = 0;
+ }
+ state->inlen = 0;
+ state->flags = IFLUSH;
+ putnext(q, mp);
+ break;
+
+ default:
+ putnext(q, mp);
+ }
+ return 0;
+}
+
+/* Extract bit c from map m, to determine if c needs to be escaped. */
+#define ESCAPE(c, m) ((m)[(c) >> 5] & (1 << ((c) & 0x1f)))
+
+static void
+stuff_frame(q, mp)
+ queue_t *q;
+ mblk_t *mp;
+{
+ ahdlc_state_t *state;
+ int ilen, olen, c, extra, i, code;
+ mblk_t *omsg, *op, *np;
+ uchar_t *sp, *sp0, *dp, *dp0, *spend;
+ ushort_t fcs;
+ u_int32_t *xaccm, lcp_xaccm[8];
+ static uchar_t lcphdr[PPP_HDRLEN] = { 0xff, 0x03, 0xc0, 0x21 };
+ uchar_t ppphdr[PPP_HDRLEN];
+
+ state = (ahdlc_state_t *) q->q_ptr;
+ ilen = msgdsize(mp);
+
+ /*
+ * We estimate the length of the output packet as
+ * 1.25 * input length + 16 (for initial flag, FCS, final flag, slop).
+ */
+ olen = ilen + (ilen >> 2) + 16;
+ if (olen > OFRAME_BSIZE)
+ olen = OFRAME_BSIZE;
+ omsg = op = allocb(olen, BPRI_MED);
+ if (omsg == 0)
+ goto bomb;
+
+ /*
+ * Put in an initial flag for now. We'll remove it later
+ * if we decide we don't need it.
+ */
+ dp = op->b_wptr;
+ *dp++ = PPP_FLAG;
+ --olen;
+
+ /*
+ * For LCP packets with code values between 1 and 7 (Conf-Req
+ * to Code-Rej), we must escape all control characters.
+ */
+ xaccm = state->xaccm;
+ if (MSG_BYTE(mp, 0) == PPP_ALLSTATIONS
+ && MSG_BYTE(mp, 1) == PPP_UI
+ && MSG_BYTE(mp, 2) == (PPP_LCP >> 8)
+ && MSG_BYTE(mp, 3) == (PPP_LCP & 0xFF)
+ && LCP_USE_DFLT(mp)) {
+ bcopy((caddr_t) state->xaccm, (caddr_t) lcp_xaccm, sizeof(lcp_xaccm));
+ lcp_xaccm[0] = ~0;
+ xaccm = lcp_xaccm;
+ }
+
+ sp = mp->b_rptr;
+ fcs = PPP_INITFCS;
+ for (;;) {
+ spend = mp->b_wptr;
+ extra = sp + olen - spend;
+ if (extra < 0) {
+ spend = sp + olen;
+ extra = 0;
+ }
+ /*
+ * We can safely process the input up to `spend'
+ * without overrunning the output, provided we don't
+ * hit more than `extra' characters which need to be escaped.
+ */
+ sp0 = sp;
+ dp0 = dp;
+ while (sp < spend) {
+ c = *sp;
+ if (ESCAPE(c, xaccm)) {
+ if (extra > 0)
+ --extra;
+ else if (sp < spend - 1)
+ --spend;
+ else
+ break;
+ fcs = PPP_FCS(fcs, c);
+ *dp++ = PPP_ESCAPE;
+ c ^= PPP_TRANS;
+ } else
+ fcs = PPP_FCS(fcs, c);
+ *dp++ = c;
+ ++sp;
+ }
+ ilen -= sp - sp0;
+ olen -= dp - dp0;
+
+ /*
+ * At this point, we have emptied an input block
+ * and/or filled an output block.
+ */
+ if (sp >= mp->b_wptr) {
+ /*
+ * We've emptied an input block. Advance to the next.
+ */
+ mp = mp->b_cont;
+ if (mp == 0)
+ break; /* all done */
+ sp = mp->b_rptr;
+ }
+ if (olen < 2) {
+ /*
+ * The output block is full. Allocate a new one.
+ */
+ op->b_wptr = dp;
+ olen = 2 * ilen + 5;
+ if (olen > OFRAME_BSIZE)
+ olen = OFRAME_BSIZE;
+ np = allocb(olen, BPRI_MED);
+ if (np == 0)
+ goto bomb;
+ op->b_cont = np;
+ op = np;
+ dp = op->b_wptr;
+ }
+ }
+
+ /*
+ * Append the FCS and closing flag.
+ * This could require up to 5 characters.
+ */
+ if (olen < 5) {
+ /* Sigh. Need another block. */
+ op->b_wptr = dp;
+ np = allocb(5, BPRI_MED);
+ if (np == 0)
+ goto bomb;
+ op->b_cont = np;
+ op = np;
+ dp = op->b_wptr;
+ }
+ c = ~fcs & 0xff;
+ if (ESCAPE(c, xaccm)) {
+ *dp++ = PPP_ESCAPE;
+ c ^= PPP_TRANS;
+ }
+ *dp++ = c;
+ c = (~fcs >> 8) & 0xff;
+ if (ESCAPE(c, xaccm)) {
+ *dp++ = PPP_ESCAPE;
+ c ^= PPP_TRANS;
+ }
+ *dp++ = c;
+ *dp++ = PPP_FLAG;
+ op->b_wptr = dp;
+
+ /*
+ * Remove the initial flag, if possible.
+ */
+ if (qsize(q->q_next) > 0)
+ ++omsg->b_rptr;
+
+ /*
+ * Update statistics.
+ */
+ state->stats.ppp_obytes += msgdsize(omsg);
+ state->stats.ppp_opackets++;
+
+ /*
+ * Send it on.
+ */
+ putnext(q, omsg);
+ return;
+
+ bomb:
+ if (omsg != 0)
+ freemsg(omsg);
+ state->stats.ppp_oerrors++;
+ putctl1(RD(q)->q_next, M_CTL, PPPCTL_OERROR);
+}
+
+#define UPDATE_FLAGS(c) { \
+ if ((c) & 0x80) \
+ state->flags |= RCV_B7_1; \
+ else \
+ state->flags |= RCV_B7_0; \
+ if (0x6996 & (1 << ((((c) >> 4) ^ (c)) & 0xf))) \
+ state->flags |= RCV_ODDP; \
+ else \
+ state->flags |= RCV_EVNP; \
+}
+
+/*
+ * Process received characters.
+ */
+static void
+unstuff_chars(q, mp)
+ queue_t *q;
+ mblk_t *mp;
+{
+ ahdlc_state_t *state;
+ mblk_t *om;
+ uchar_t *cp, *cpend, *dp, *dp0;
+ int c, len, extra, offset;
+ ushort_t fcs;
+
+ state = (ahdlc_state_t *) q->q_ptr;
+ state->stats.ppp_ibytes += msgdsize(mp);
+ cp = mp->b_rptr;
+ for (;;) {
+ /*
+ * Advance to next input block if necessary.
+ */
+ if (cp >= mp->b_wptr) {
+ mp = mp->b_cont;
+ if (mp == 0)
+ break;
+ cp = mp->b_rptr;
+ continue;
+ }
+
+ if ((state->flags & (IFLUSH|ESCAPED)) == 0
+ && state->inlen > 0 && (om = state->cur_blk) != 0) {
+ /*
+ * Process bulk chars as quickly as possible.
+ */
+ dp = om->b_wptr;
+ len = om->b_datap->db_lim - dp; /* max # output bytes */
+ extra = (mp->b_wptr - cp) - len;/* #input chars - #output bytes */
+ if (extra < 0) {
+ len += extra; /* we'll run out of input first */
+ extra = 0;
+ }
+ cpend = cp + len;
+ dp0 = dp;
+ fcs = state->infcs;
+ while (cp < cpend) {
+ c = *cp;
+ if (c == PPP_FLAG)
+ break;
+ ++cp;
+ UPDATE_FLAGS(c);
+ if (c == PPP_ESCAPE) {
+ if (extra > 0) {
+ --extra;
+ ++cpend;
+ }
+ if (cp >= cpend || (c = *cp) == PPP_FLAG) {
+ state->flags |= ESCAPED;
+ break;
+ }
+ ++cp;
+ UPDATE_FLAGS(c);
+ c ^= PPP_TRANS;
+ }
+ *dp++ = c;
+ fcs = PPP_FCS(fcs, c);
+ }
+ state->inlen += dp - dp0;
+ state->infcs = fcs;
+ om->b_wptr = dp;
+ if (cp >= mp->b_wptr)
+ continue; /* advance to the next mblk */
+ }
+
+ c = *cp++;
+ UPDATE_FLAGS(c);
+ if (c == PPP_FLAG) {
+ /*
+ * End of a frame.
+ * If the ESCAPE flag is set, the frame ended with
+ * the frame abort sequence "}~".
+ */
+ om = state->cur_frame;
+ len = state->inlen;
+ state->cur_frame = 0;
+ state->inlen = 0;
+ if (len == 0 && (state->flags & IFLUSH) == 0)
+ continue;
+ state->stats.ppp_ipackets++;
+ if (om != 0 && (state->flags & (IFLUSH|ESCAPED)) == 0
+ && len > PPP_FCSLEN) {
+ if (state->infcs == PPP_GOODFCS) {
+ adjmsg(om, -PPP_FCSLEN); /* chop off fcs */
+ putnext(q, om); /* bombs away! */
+ continue;
+ }
+ DPRINT1("ppp_ahdl: bad fcs %x\n", state->infcs);
+ }
+ if (om != 0)
+ freemsg(om);
+ state->stats.ppp_ierrors++;
+ putctl1(q->q_next, M_CTL, PPPCTL_IERROR);
+ continue;
+ }
+
+ if (state->flags & IFLUSH)
+ continue;
+ if (state->flags & ESCAPED) {
+ c ^= PPP_TRANS;
+ state->flags &= ~ESCAPED;
+ } else if (c == PPP_ESCAPE) {
+ state->flags |= ESCAPED;
+ continue;
+ }
+ if (state->inlen == 0) {
+ /*
+ * First byte of the frame: allocate the first message block.
+ */
+ om = allocb(IFRAME_BSIZE, BPRI_MED);
+ if (om == 0) {
+ state->flags |= IFLUSH;
+ continue;
+ }
+ state->cur_frame = om;
+ state->cur_blk = om;
+ state->infcs = PPP_INITFCS;
+ } else {
+ om = state->cur_blk;
+ if (om->b_wptr >= om->b_datap->db_lim) {
+ /*
+ * Current message block is full. Allocate another one,
+ * unless we have run out of MRU.
+ */
+ if (state->inlen >= state->mru + PPP_HDRLEN + PPP_FCSLEN) {
+ state->flags |= IFLUSH;
+ DPRINT1("ppp_ahdl: frame too long (%d)\n", state->inlen);
+ continue;
+ }
+ om = allocb(IFRAME_BSIZE, BPRI_MED);
+ if (om == 0) {
+ state->flags |= IFLUSH;
+ continue;
+ }
+ state->cur_blk->b_cont = om;
+ state->cur_blk = om;
+ }
+ }
+
+ if (state->inlen == 0) {
+ /*
+ * We don't do address/control & protocol decompression here,
+ * but we try to put the first byte at an offset such that
+ * the info field starts on a word boundary. The code here
+ * will do this except for packets with protocol compression
+ * but not address/control compression.
+ */
+ if (c != PPP_ALLSTATIONS) {
+ om->b_wptr += 2;
+ if (c & 1)
+ ++om->b_wptr;
+ om->b_rptr = om->b_wptr;
+ }
+ }
+
+ *om->b_wptr++ = c;
+ ++state->inlen;
+ state->infcs = PPP_FCS(state->infcs, c);
+ }
+}
+
+static int
+msg_byte(mp, i)
+ mblk_t *mp;
+ unsigned int i;
+{
+ while (mp != 0 && i >= mp->b_wptr - mp->b_rptr)
+ mp = mp->b_cont;
+ if (mp == 0)
+ return -1;
+ return mp->b_rptr[i];
+}
projects / ppp.git / blobdiff