X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=modules%2Fppp_ahdlc.c;fp=modules%2Fppp_ahdlc.c;h=ba4f41c126b6276c31b64fe844118d6b3797e59d;hb=a44a616baa968a263dc273bc06ed79c475b7deec;hp=0000000000000000000000000000000000000000;hpb=b4be00b380f87488cf898882e0551ba535146194;p=ppp.git diff --git a/modules/ppp_ahdlc.c b/modules/ppp_ahdlc.c new file mode 100644 index 0000000..ba4f41c --- /dev/null +++ b/modules/ppp_ahdlc.c @@ -0,0 +1,710 @@ +/* + * 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 +#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) + +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]; +}