/* * 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 1.2 1996/06/26 00:54:01 paulus Exp $ */ /* * This file is used under Solaris 2, SVR4, SunOS 4, and Digital UNIX. */ #include #include #include #include #ifdef SVR4 #include #include #include #include #else #include #endif /* SVR4 */ #include #include #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) #define PPP_AHDL_ID 0x7d23 static struct module_info minfo = { PPP_AHDL_ID, "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; } DPRINT2("ppp%d: bad fcs (len=%d)\n", state->unit, len); } if (om != 0) freemsg(om); state->flags &= ~(IFLUSH|ESCAPED); 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; DPRINT2("ppp%d: frame too long (%d)\n", state->unit, 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]; }