/* * lcp.c - PPP Link Control Protocol. * * Copyright (c) 1989 Carnegie Mellon University. * All rights reserved. * * Redistribution and use in source and binary forms are permitted * provided that the above copyright notice and this paragraph are * duplicated in all such forms and that any documentation, * advertising materials, and other materials related to such * distribution and use acknowledge that the software was developed * by Carnegie Mellon University. The name of the * University may not be used to endorse or promote products derived * from this software without specific prior written permission. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ #ifndef lint static char rcsid[] = "$Id: lcp.c,v 1.8 1994/06/28 04:38:40 paulus Exp $"; #endif /* * TODO: */ #include #include #include #include #include #include #include #include #include #include "pppd.h" #include "ppp.h" #include "fsm.h" #include "lcp.h" #include "magic.h" #include "chap.h" #include "upap.h" #include "ipcp.h" /* global vars */ fsm lcp_fsm[NPPP]; /* LCP fsm structure (global)*/ lcp_options lcp_wantoptions[NPPP]; /* Options that we want to request */ lcp_options lcp_gotoptions[NPPP]; /* Options that peer ack'd */ lcp_options lcp_allowoptions[NPPP]; /* Options we allow peer to request */ lcp_options lcp_hisoptions[NPPP]; /* Options that we ack'd */ u_long xmit_accm[NPPP][8]; /* extended transmit ACCM */ static u_long lcp_echos_pending = 0; /* Number of outstanding echo msgs */ static u_long lcp_echo_number = 0; /* ID number of next echo frame */ static u_long lcp_echo_timer_running = 0; /* TRUE if a timer is running */ u_long lcp_echo_interval = 0; u_long lcp_echo_fails = 0; /* * Callbacks for fsm code. (CI = Configuration Information) */ static void lcp_resetci __ARGS((fsm *)); /* Reset our CI */ static int lcp_cilen __ARGS((fsm *)); /* Return length of our CI */ static void lcp_addci __ARGS((fsm *, u_char *, int *)); /* Add our CI to pkt */ static int lcp_ackci __ARGS((fsm *, u_char *, int)); /* Peer ack'd our CI */ static int lcp_nakci __ARGS((fsm *, u_char *, int)); /* Peer nak'd our CI */ static int lcp_rejci __ARGS((fsm *, u_char *, int)); /* Peer rej'd our CI */ static int lcp_reqci __ARGS((fsm *, u_char *, int *, int)); /* Rcv peer CI */ static void lcp_up __ARGS((fsm *)); /* We're UP */ static void lcp_down __ARGS((fsm *)); /* We're DOWN */ static void lcp_starting __ARGS((fsm *)); /* We need lower layer up */ static void lcp_finished __ARGS((fsm *)); /* We need lower layer down */ static int lcp_extcode __ARGS((fsm *, int, int, u_char *, int)); static void lcp_rprotrej __ARGS((fsm *, u_char *, int)); /* * routines to send LCP echos to peer */ static void lcp_echo_lowerup __ARGS((int)); static void lcp_echo_lowerdown __ARGS((int)); static void LcpEchoTimeout __ARGS((caddr_t)); static void lcp_received_echo_reply __ARGS((fsm *, int, u_char *, int)); static void LcpSendEchoRequest __ARGS((fsm *)); static void LcpLinkFailure __ARGS((fsm *)); static fsm_callbacks lcp_callbacks = { /* LCP callback routines */ lcp_resetci, /* Reset our Configuration Information */ lcp_cilen, /* Length of our Configuration Information */ lcp_addci, /* Add our Configuration Information */ lcp_ackci, /* ACK our Configuration Information */ lcp_nakci, /* NAK our Configuration Information */ lcp_rejci, /* Reject our Configuration Information */ lcp_reqci, /* Request peer's Configuration Information */ lcp_up, /* Called when fsm reaches OPENED state */ lcp_down, /* Called when fsm leaves OPENED state */ lcp_starting, /* Called when we want the lower layer up */ lcp_finished, /* Called when we want the lower layer down */ NULL, /* Called when Protocol-Reject received */ NULL, /* Retransmission is necessary */ lcp_extcode, /* Called to handle LCP-specific codes */ "LCP" /* String name of protocol */ }; int lcp_warnloops = DEFWARNLOOPS; /* Warn about a loopback this often */ /* * Length of each type of configuration option (in octets) */ #define CILEN_VOID 2 #define CILEN_SHORT 4 /* CILEN_VOID + sizeof(short) */ #define CILEN_CHAP 5 /* CILEN_VOID + sizeof(short) + 1 */ #define CILEN_LONG 6 /* CILEN_VOID + sizeof(long) */ #define CILEN_LQR 8 /* CILEN_VOID + sizeof(short) + sizeof(long) */ #define CODENAME(x) ((x) == CONFACK ? "ACK" : \ (x) == CONFNAK ? "NAK" : "REJ") /* * lcp_init - Initialize LCP. */ void lcp_init(unit) int unit; { fsm *f = &lcp_fsm[unit]; lcp_options *wo = &lcp_wantoptions[unit]; lcp_options *ao = &lcp_allowoptions[unit]; f->unit = unit; f->protocol = LCP; f->callbacks = &lcp_callbacks; fsm_init(f); wo->passive = 0; wo->silent = 0; wo->restart = 0; /* Set to 1 in kernels or multi-line implementations */ wo->neg_mru = 1; wo->mru = DEFMRU; wo->neg_asyncmap = 0; wo->asyncmap = 0; wo->neg_chap = 0; /* Set to 1 on server */ wo->neg_upap = 0; /* Set to 1 on server */ wo->chap_mdtype = CHAP_DIGEST_MD5; wo->neg_magicnumber = 1; wo->neg_pcompression = 1; wo->neg_accompression = 1; wo->neg_lqr = 0; /* no LQR implementation yet */ ao->neg_mru = 1; ao->mru = MAXMRU; ao->neg_asyncmap = 1; ao->asyncmap = 0; ao->neg_chap = 1; ao->chap_mdtype = CHAP_DIGEST_MD5; ao->neg_upap = 1; ao->neg_magicnumber = 1; ao->neg_pcompression = 1; ao->neg_accompression = 1; ao->neg_lqr = 0; /* no LQR implementation yet */ memset(xmit_accm[unit], 0, sizeof(xmit_accm[0])); xmit_accm[unit][3] = 0x60000000; } /* * lcp_open - LCP is allowed to come up. */ void lcp_open(unit) int unit; { fsm *f = &lcp_fsm[unit]; lcp_options *wo = &lcp_wantoptions[unit]; f->flags = 0; if (wo->passive) f->flags |= OPT_PASSIVE; if (wo->silent) f->flags |= OPT_SILENT; fsm_open(f); } /* * lcp_close - Take LCP down. */ void lcp_close(unit) int unit; { fsm *f = &lcp_fsm[unit]; if (f->state == STOPPED && f->flags & (OPT_PASSIVE|OPT_SILENT)) { /* * This action is not strictly according to the FSM in RFC1548, * but it does mean that the program terminates if you do a * lcp_close(0) in passive/silent mode when a connection hasn't * been established. */ f->state = CLOSED; lcp_finished(f); } else fsm_close(&lcp_fsm[unit]); } /* * lcp_lowerup - The lower layer is up. */ void lcp_lowerup(unit) int unit; { sifdown(unit); ppp_set_xaccm(unit, xmit_accm[unit]); ppp_send_config(unit, MTU, 0xffffffff, 0, 0); ppp_recv_config(unit, MTU, 0x00000000, 0, 0); peer_mru[unit] = MTU; lcp_allowoptions[unit].asyncmap = xmit_accm[unit][0]; fsm_lowerup(&lcp_fsm[unit]); } /* * lcp_lowerdown - The lower layer is down. */ void lcp_lowerdown(unit) int unit; { fsm_lowerdown(&lcp_fsm[unit]); } /* * lcp_input - Input LCP packet. */ void lcp_input(unit, p, len) int unit; u_char *p; int len; { fsm_input(&lcp_fsm[unit], p, len); } /* * lcp_extcode - Handle a LCP-specific code. */ static int lcp_extcode(f, code, id, inp, len) fsm *f; int code, id; u_char *inp; int len; { u_char *magp; switch( code ){ case PROTREJ: lcp_rprotrej(f, inp, len); break; case ECHOREQ: if (f->state != OPENED) break; LCPDEBUG((LOG_INFO, "lcp: Echo-Request, Rcvd id %d", id)); magp = inp; PUTLONG(lcp_gotoptions[f->unit].magicnumber, magp); if (len < CILEN_LONG) len = CILEN_LONG; fsm_sdata(f, ECHOREP, id, inp, len); break; case ECHOREP: lcp_received_echo_reply(f, id, inp, len); break; case DISCREQ: break; default: return 0; } return 1; } /* * lcp_rprotrej - Receive an Protocol-Reject. * * Figure out which protocol is rejected and inform it. */ static void lcp_rprotrej(f, inp, len) fsm *f; u_char *inp; int len; { u_short prot; LCPDEBUG((LOG_INFO, "lcp_rprotrej.")); if (len < sizeof (u_short)) { LCPDEBUG((LOG_INFO, "lcp_rprotrej: Rcvd short Protocol-Reject packet!")); return; } GETSHORT(prot, inp); LCPDEBUG((LOG_INFO, "lcp_rprotrej: Rcvd Protocol-Reject packet for %x!", prot)); /* * Protocol-Reject packets received in any state other than the LCP * OPENED state SHOULD be silently discarded. */ if( f->state != OPENED ){ LCPDEBUG((LOG_INFO, "Protocol-Reject discarded: LCP in state %d", f->state)); return; } DEMUXPROTREJ(f->unit, prot); /* Inform protocol */ } /* * lcp_protrej - A Protocol-Reject was received. */ /*ARGSUSED*/ void lcp_protrej(unit) int unit; { /* * Can't reject LCP! */ LCPDEBUG((LOG_WARNING, "lcp_protrej: Received Protocol-Reject for LCP!")); fsm_protreject(&lcp_fsm[unit]); } /* * lcp_sprotrej - Send a Protocol-Reject for some protocol. */ void lcp_sprotrej(unit, p, len) int unit; u_char *p; int len; { /* * Send back the protocol and the information field of the * rejected packet. We only get here if LCP is in the OPENED state. */ p += 2; len -= 2; fsm_sdata(&lcp_fsm[unit], PROTREJ, ++lcp_fsm[unit].id, p, len); } /* * lcp_resetci - Reset our CI. */ static void lcp_resetci(f) fsm *f; { lcp_wantoptions[f->unit].magicnumber = magic(); lcp_wantoptions[f->unit].numloops = 0; lcp_gotoptions[f->unit] = lcp_wantoptions[f->unit]; peer_mru[f->unit] = MTU; } /* * lcp_cilen - Return length of our CI. */ static int lcp_cilen(f) fsm *f; { lcp_options *go = &lcp_gotoptions[f->unit]; #define LENCIVOID(neg) (neg ? CILEN_VOID : 0) #define LENCICHAP(neg) (neg ? CILEN_CHAP : 0) #define LENCISHORT(neg) (neg ? CILEN_SHORT : 0) #define LENCILONG(neg) (neg ? CILEN_LONG : 0) #define LENCILQR(neg) (neg ? CILEN_LQR: 0) /* * NB: we only ask for one of CHAP and UPAP, even if we will * accept either. */ return (LENCISHORT(go->neg_mru) + LENCILONG(go->neg_asyncmap) + LENCICHAP(go->neg_chap) + LENCISHORT(!go->neg_chap && go->neg_upap) + LENCILQR(go->neg_lqr) + LENCILONG(go->neg_magicnumber) + LENCIVOID(go->neg_pcompression) + LENCIVOID(go->neg_accompression)); } /* * lcp_addci - Add our desired CIs to a packet. */ static void lcp_addci(f, ucp, lenp) fsm *f; u_char *ucp; int *lenp; { lcp_options *go = &lcp_gotoptions[f->unit]; u_char *start_ucp = ucp; #define ADDCIVOID(opt, neg) \ if (neg) { \ PUTCHAR(opt, ucp); \ PUTCHAR(CILEN_VOID, ucp); \ } #define ADDCISHORT(opt, neg, val) \ if (neg) { \ PUTCHAR(opt, ucp); \ PUTCHAR(CILEN_SHORT, ucp); \ PUTSHORT(val, ucp); \ } #define ADDCICHAP(opt, neg, val, digest) \ if (neg) { \ PUTCHAR(opt, ucp); \ PUTCHAR(CILEN_CHAP, ucp); \ PUTSHORT(val, ucp); \ PUTCHAR(digest, ucp); \ } #define ADDCILONG(opt, neg, val) \ if (neg) { \ PUTCHAR(opt, ucp); \ PUTCHAR(CILEN_LONG, ucp); \ PUTLONG(val, ucp); \ } #define ADDCILQR(opt, neg, val) \ if (neg) { \ PUTCHAR(opt, ucp); \ PUTCHAR(CILEN_LQR, ucp); \ PUTSHORT(LQR, ucp); \ PUTLONG(val, ucp); \ } ADDCISHORT(CI_MRU, go->neg_mru, go->mru); ADDCILONG(CI_ASYNCMAP, go->neg_asyncmap, go->asyncmap); ADDCICHAP(CI_AUTHTYPE, go->neg_chap, CHAP, go->chap_mdtype); ADDCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, UPAP); ADDCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period); ADDCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber); ADDCIVOID(CI_PCOMPRESSION, go->neg_pcompression); ADDCIVOID(CI_ACCOMPRESSION, go->neg_accompression); if (ucp - start_ucp != *lenp) { /* this should never happen, because peer_mtu should be 1500 */ syslog(LOG_ERR, "Bug in lcp_addci: wrong length"); } } /* * lcp_ackci - Ack our CIs. * This should not modify any state if the Ack is bad. * * Returns: * 0 - Ack was bad. * 1 - Ack was good. */ static int lcp_ackci(f, p, len) fsm *f; u_char *p; int len; { lcp_options *go = &lcp_gotoptions[f->unit]; u_char cilen, citype, cichar; u_short cishort; u_long cilong; /* * CIs must be in exactly the same order that we sent. * Check packet length and CI length at each step. * If we find any deviations, then this packet is bad. */ #define ACKCIVOID(opt, neg) \ if (neg) { \ if ((len -= CILEN_VOID) < 0) \ goto bad; \ GETCHAR(citype, p); \ GETCHAR(cilen, p); \ if (cilen != CILEN_VOID || \ citype != opt) \ goto bad; \ } #define ACKCISHORT(opt, neg, val) \ if (neg) { \ if ((len -= CILEN_SHORT) < 0) \ goto bad; \ GETCHAR(citype, p); \ GETCHAR(cilen, p); \ if (cilen != CILEN_SHORT || \ citype != opt) \ goto bad; \ GETSHORT(cishort, p); \ if (cishort != val) \ goto bad; \ } #define ACKCICHAP(opt, neg, val, digest) \ if (neg) { \ if ((len -= CILEN_CHAP) < 0) \ goto bad; \ GETCHAR(citype, p); \ GETCHAR(cilen, p); \ if (cilen != CILEN_CHAP || \ citype != opt) \ goto bad; \ GETSHORT(cishort, p); \ if (cishort != val) \ goto bad; \ GETCHAR(cichar, p); \ if (cichar != digest) \ goto bad; \ } #define ACKCILONG(opt, neg, val) \ if (neg) { \ if ((len -= CILEN_LONG) < 0) \ goto bad; \ GETCHAR(citype, p); \ GETCHAR(cilen, p); \ if (cilen != CILEN_LONG || \ citype != opt) \ goto bad; \ GETLONG(cilong, p); \ if (cilong != val) \ goto bad; \ } #define ACKCILQR(opt, neg, val) \ if (neg) { \ if ((len -= CILEN_LQR) < 0) \ goto bad; \ GETCHAR(citype, p); \ GETCHAR(cilen, p); \ if (cilen != CILEN_LQR || \ citype != opt) \ goto bad; \ GETSHORT(cishort, p); \ if (cishort != LQR) \ goto bad; \ GETLONG(cilong, p); \ if (cilong != val) \ goto bad; \ } ACKCISHORT(CI_MRU, go->neg_mru, go->mru); ACKCILONG(CI_ASYNCMAP, go->neg_asyncmap, go->asyncmap); ACKCICHAP(CI_AUTHTYPE, go->neg_chap, CHAP, go->chap_mdtype); ACKCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, UPAP); ACKCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period); ACKCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber); ACKCIVOID(CI_PCOMPRESSION, go->neg_pcompression); ACKCIVOID(CI_ACCOMPRESSION, go->neg_accompression); /* * If there are any remaining CIs, then this packet is bad. */ if (len != 0) goto bad; return (1); bad: LCPDEBUG((LOG_WARNING, "lcp_acki: received bad Ack!")); return (0); } /* * lcp_nakci - Peer has sent a NAK for some of our CIs. * This should not modify any state if the Nak is bad * or if LCP is in the OPENED state. * * Returns: * 0 - Nak was bad. * 1 - Nak was good. */ static int lcp_nakci(f, p, len) fsm *f; u_char *p; int len; { lcp_options *go = &lcp_gotoptions[f->unit]; lcp_options *wo = &lcp_wantoptions[f->unit]; u_char cilen, citype, cichar, *next; u_short cishort; u_long cilong; lcp_options no; /* options we've seen Naks for */ lcp_options try; /* options to request next time */ int looped_back = 0; BZERO(&no, sizeof(no)); try = *go; /* * Any Nak'd CIs must be in exactly the same order that we sent. * Check packet length and CI length at each step. * If we find any deviations, then this packet is bad. */ #define NAKCIVOID(opt, neg, code) \ if (go->neg && \ len >= CILEN_VOID && \ p[1] == CILEN_VOID && \ p[0] == opt) { \ len -= CILEN_VOID; \ INCPTR(CILEN_VOID, p); \ no.neg = 1; \ code \ } #define NAKCICHAP(opt, neg, code) \ if (go->neg && \ len >= CILEN_CHAP && \ p[1] == CILEN_CHAP && \ p[0] == opt) { \ len -= CILEN_CHAP; \ INCPTR(2, p); \ GETSHORT(cishort, p); \ GETCHAR(cichar, p); \ no.neg = 1; \ code \ } #define NAKCISHORT(opt, neg, code) \ if (go->neg && \ len >= CILEN_SHORT && \ p[1] == CILEN_SHORT && \ p[0] == opt) { \ len -= CILEN_SHORT; \ INCPTR(2, p); \ GETSHORT(cishort, p); \ no.neg = 1; \ code \ } #define NAKCILONG(opt, neg, code) \ if (go->neg && \ len >= CILEN_LONG && \ p[1] == CILEN_LONG && \ p[0] == opt) { \ len -= CILEN_LONG; \ INCPTR(2, p); \ GETLONG(cilong, p); \ no.neg = 1; \ code \ } #define NAKCILQR(opt, neg, code) \ if (go->neg && \ len >= CILEN_LQR && \ p[1] == CILEN_LQR && \ p[0] == opt) { \ len -= CILEN_LQR; \ INCPTR(2, p); \ GETSHORT(cishort, p); \ GETLONG(cilong, p); \ no.neg = 1; \ code \ } /* * We don't care if they want to send us smaller packets than * we want. Therefore, accept any MRU less than what we asked for, * but then ignore the new value when setting the MRU in the kernel. * If they send us a bigger MRU than what we asked, accept it, up to * the limit of the default MRU we'd get if we didn't negotiate. */ NAKCISHORT(CI_MRU, neg_mru, if (cishort <= wo->mru || cishort < DEFMRU) try.mru = cishort; ); /* * Add any characters they want to our (receive-side) asyncmap. */ NAKCILONG(CI_ASYNCMAP, neg_asyncmap, try.asyncmap = go->asyncmap | cilong; ); /* * If they can't cope with our CHAP hash algorithm, we'll have * to stop asking for CHAP. We haven't got any other algorithm. */ NAKCICHAP(CI_AUTHTYPE, neg_chap, try.neg_chap = 0; ); /* * Peer shouldn't send Nak for UPAP, protocol compression or * address/control compression requests; they should send * a Reject instead. If they send a Nak, treat it as a Reject. */ if (!go->neg_chap ){ NAKCISHORT(CI_AUTHTYPE, neg_upap, try.neg_upap = 0; ); } /* * If they can't cope with our link quality protocol, we'll have * to stop asking for LQR. We haven't got any other protocol. * If they Nak the reporting period, take their value XXX ? */ NAKCILQR(CI_QUALITY, neg_lqr, if (cishort != LQR) try.neg_lqr = 0; else try.lqr_period = cilong; ); /* * Check for a looped-back line. */ NAKCILONG(CI_MAGICNUMBER, neg_magicnumber, try.magicnumber = magic(); ++try.numloops; looped_back = 1; ); NAKCIVOID(CI_PCOMPRESSION, neg_pcompression, try.neg_pcompression = 0; ); NAKCIVOID(CI_ACCOMPRESSION, neg_accompression, try.neg_accompression = 0; ); /* * There may be remaining CIs, if the peer is requesting negotiation * on an option that we didn't include in our request packet. * If we see an option that we requested, or one we've already seen * in this packet, then this packet is bad. * If we wanted to respond by starting to negotiate on the requested * option(s), we could, but we don't, because except for the * authentication type and quality protocol, if we are not negotiating * an option, it is because we were told not to. * For the authentication type, the Nak from the peer means * `let me authenticate myself with you' which is a bit pointless. * For the quality protocol, the Nak means `ask me to send you quality * reports', but if we didn't ask for them, we don't want them. */ while (len > CILEN_VOID) { GETCHAR(citype, p); GETCHAR(cilen, p); if( (len -= cilen) < 0 ) goto bad; next = p + cilen - 2; switch (citype) { case CI_MRU: if (go->neg_mru || no.neg_mru || cilen != CILEN_SHORT) goto bad; break; case CI_ASYNCMAP: if (go->neg_asyncmap || no.neg_asyncmap || cilen != CILEN_LONG) goto bad; break; case CI_AUTHTYPE: if (go->neg_chap || no.neg_chap || go->neg_upap || no.neg_upap) goto bad; break; case CI_MAGICNUMBER: if (go->neg_magicnumber || no.neg_magicnumber || cilen != CILEN_LONG) goto bad; break; case CI_PCOMPRESSION: if (go->neg_pcompression || no.neg_pcompression || cilen != CILEN_VOID) goto bad; break; case CI_ACCOMPRESSION: if (go->neg_accompression || no.neg_accompression || cilen != CILEN_VOID) goto bad; break; case CI_QUALITY: if (go->neg_lqr || no.neg_lqr || cilen != CILEN_LQR) goto bad; break; default: goto bad; } p = next; } /* If there is still anything left, this packet is bad. */ if (len != 0) goto bad; /* * OK, the Nak is good. Now we can update state. */ if (f->state != OPENED) { *go = try; if (looped_back && try.numloops % lcp_warnloops == 0) syslog(LOG_WARNING, "The line appears to be looped back."); } return 1; bad: LCPDEBUG((LOG_WARNING, "lcp_nakci: received bad Nak!")); return 0; } /* * lcp_rejci - Peer has Rejected some of our CIs. * This should not modify any state if the Reject is bad * or if LCP is in the OPENED state. * * Returns: * 0 - Reject was bad. * 1 - Reject was good. */ static int lcp_rejci(f, p, len) fsm *f; u_char *p; int len; { lcp_options *go = &lcp_gotoptions[f->unit]; u_char cichar; u_short cishort; u_long cilong; u_char *start = p; int plen = len; lcp_options try; /* options to request next time */ try = *go; /* * Any Rejected CIs must be in exactly the same order that we sent. * Check packet length and CI length at each step. * If we find any deviations, then this packet is bad. */ #define REJCIVOID(opt, neg) \ if (go->neg && \ len >= CILEN_VOID && \ p[1] == CILEN_VOID && \ p[0] == opt) { \ len -= CILEN_VOID; \ INCPTR(CILEN_VOID, p); \ try.neg = 0; \ LCPDEBUG((LOG_INFO, "lcp_rejci rejected void opt %d", opt)); \ } #define REJCISHORT(opt, neg, val) \ if (go->neg && \ len >= CILEN_SHORT && \ p[1] == CILEN_SHORT && \ p[0] == opt) { \ len -= CILEN_SHORT; \ INCPTR(2, p); \ GETSHORT(cishort, p); \ /* Check rejected value. */ \ if (cishort != val) \ goto bad; \ try.neg = 0; \ LCPDEBUG((LOG_INFO,"lcp_rejci rejected short opt %d", opt)); \ } #define REJCICHAP(opt, neg, val, digest) \ if (go->neg && \ len >= CILEN_CHAP && \ p[1] == CILEN_CHAP && \ p[0] == opt) { \ len -= CILEN_CHAP; \ INCPTR(2, p); \ GETSHORT(cishort, p); \ GETCHAR(cichar, p); \ /* Check rejected value. */ \ if (cishort != val || cichar != digest) \ goto bad; \ try.neg = 0; \ LCPDEBUG((LOG_INFO,"lcp_rejci rejected chap opt %d", opt)); \ } #define REJCILONG(opt, neg, val) \ if (go->neg && \ len >= CILEN_LONG && \ p[1] == CILEN_LONG && \ p[0] == opt) { \ len -= CILEN_LONG; \ INCPTR(2, p); \ GETLONG(cilong, p); \ /* Check rejected value. */ \ if (cilong != val) \ goto bad; \ try.neg = 0; \ LCPDEBUG((LOG_INFO,"lcp_rejci rejected long opt %d", opt)); \ } #define REJCILQR(opt, neg, val) \ if (go->neg && \ len >= CILEN_LQR && \ p[1] == CILEN_LQR && \ p[0] == opt) { \ len -= CILEN_LQR; \ INCPTR(2, p); \ GETSHORT(cishort, p); \ GETLONG(cilong, p); \ /* Check rejected value. */ \ if (cishort != LQR || cilong != val) \ goto bad; \ try.neg = 0; \ LCPDEBUG((LOG_INFO,"lcp_rejci rejected LQR opt %d", opt)); \ } REJCISHORT(CI_MRU, neg_mru, go->mru); REJCILONG(CI_ASYNCMAP, neg_asyncmap, go->asyncmap); REJCICHAP(CI_AUTHTYPE, neg_chap, CHAP, go->chap_mdtype); if (!go->neg_chap) { REJCISHORT(CI_AUTHTYPE, neg_upap, UPAP); } REJCILQR(CI_QUALITY, neg_lqr, go->lqr_period); REJCILONG(CI_MAGICNUMBER, neg_magicnumber, go->magicnumber); REJCIVOID(CI_PCOMPRESSION, neg_pcompression); REJCIVOID(CI_ACCOMPRESSION, neg_accompression); /* * If there are any remaining CIs, then this packet is bad. */ if (len != 0) goto bad; /* * Now we can update state. */ if (f->state != OPENED) *go = try; return 1; bad: LCPDEBUG((LOG_WARNING, "lcp_rejci: received bad Reject!")); LCPDEBUG((LOG_WARNING, "lcp_rejci: plen %d len %d off %d", plen, len, p - start)); return 0; } /* * lcp_reqci - Check the peer's requested CIs and send appropriate response. * * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified * appropriately. If reject_if_disagree is non-zero, doesn't return * CONFNAK; returns CONFREJ if it can't return CONFACK. */ static int lcp_reqci(f, inp, lenp, reject_if_disagree) fsm *f; u_char *inp; /* Requested CIs */ int *lenp; /* Length of requested CIs */ int reject_if_disagree; { lcp_options *go = &lcp_gotoptions[f->unit]; lcp_options *ho = &lcp_hisoptions[f->unit]; lcp_options *ao = &lcp_allowoptions[f->unit]; u_char *cip, *next; /* Pointer to current and next CIs */ u_char cilen, citype, cichar;/* Parsed len, type, char value */ u_short cishort; /* Parsed short value */ u_long cilong; /* Parse long value */ int rc = CONFACK; /* Final packet return code */ int orc; /* Individual option return code */ u_char *p; /* Pointer to next char to parse */ u_char *ucp = inp; /* Pointer to current output char */ int l = *lenp; /* Length left */ /* * Reset all his options. */ BZERO(ho, sizeof(*ho)); /* * Process all his options. */ next = inp; while (l) { orc = CONFACK; /* Assume success */ cip = p = next; /* Remember begining of CI */ if (l < 2 || /* Not enough data for CI header or */ p[1] < 2 || /* CI length too small or */ p[1] > l) { /* CI length too big? */ LCPDEBUG((LOG_WARNING, "lcp_reqci: bad CI length!")); orc = CONFREJ; /* Reject bad CI */ cilen = l; /* Reject till end of packet */ l = 0; /* Don't loop again */ goto endswitch; } GETCHAR(citype, p); /* Parse CI type */ GETCHAR(cilen, p); /* Parse CI length */ l -= cilen; /* Adjust remaining length */ next += cilen; /* Step to next CI */ switch (citype) { /* Check CI type */ case CI_MRU: LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd MRU")); if (!ao->neg_mru || /* Allow option? */ cilen != CILEN_SHORT) { /* Check CI length */ orc = CONFREJ; /* Reject CI */ break; } GETSHORT(cishort, p); /* Parse MRU */ LCPDEBUG((LOG_INFO, "(%d)", cishort)); /* * He must be able to receive at least our minimum. * No need to check a maximum. If he sends a large number, * we'll just ignore it. */ if (cishort < MINMRU) { orc = CONFNAK; /* Nak CI */ if( !reject_if_disagree ){ DECPTR(sizeof (short), p); /* Backup */ PUTSHORT(MINMRU, p); /* Give him a hint */ } break; } ho->neg_mru = 1; /* Remember he sent MRU */ ho->mru = cishort; /* And remember value */ break; case CI_ASYNCMAP: LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd ASYNCMAP")); if (!ao->neg_asyncmap || cilen != CILEN_LONG) { orc = CONFREJ; break; } GETLONG(cilong, p); LCPDEBUG((LOG_INFO, "(%lx)", cilong)); /* * Asyncmap must have set at least the bits * which are set in lcp_allowoptions[unit].asyncmap. */ if ((ao->asyncmap & ~cilong) != 0) { orc = CONFNAK; if( !reject_if_disagree ){ DECPTR(sizeof (long), p); PUTLONG(ao->asyncmap | cilong, p); } break; } ho->neg_asyncmap = 1; ho->asyncmap = cilong; break; case CI_AUTHTYPE: LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd AUTHTYPE")); if (cilen < CILEN_SHORT || !(ao->neg_upap || ao->neg_chap)) { orc = CONFREJ; break; } GETSHORT(cishort, p); LCPDEBUG((LOG_INFO, "(%x)", cishort)); /* * Authtype must be UPAP or CHAP. * * Note: if both ao->neg_upap and ao->neg_chap are set, * and the peer sends a Configure-Request with two * authenticate-protocol requests, one for CHAP and one * for UPAP, then we will reject the second request. * Whether we end up doing CHAP or UPAP depends then on * the ordering of the CIs in the peer's Configure-Request. */ if (cishort == UPAP) { if (!ao->neg_upap || /* we don't want to do PAP */ ho->neg_chap || /* or we've already accepted CHAP */ cilen != CILEN_SHORT) { LCPDEBUG((LOG_WARNING, "lcp_reqci: rcvd AUTHTYPE PAP, rejecting...")); orc = CONFREJ; break; } ho->neg_upap = 1; break; } if (cishort == CHAP) { if (!ao->neg_chap || /* we don't want to do CHAP */ ho->neg_upap || /* or we've already accepted UPAP */ cilen != CILEN_CHAP) { LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd AUTHTYPE CHAP, rejecting...")); orc = CONFREJ; break; } GETCHAR(cichar, p); /* get digest type*/ if (cichar != ao->chap_mdtype) { orc = CONFNAK; if( !reject_if_disagree ){ DECPTR(sizeof (u_char), p); PUTCHAR(ao->chap_mdtype, p); } break; } ho->chap_mdtype = cichar; /* save md type */ ho->neg_chap = 1; break; } /* * We don't recognize the protocol they're asking for. * Reject it. */ orc = CONFREJ; break; case CI_QUALITY: LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd QUALITY")); if (!ao->neg_lqr || cilen != CILEN_LQR) { orc = CONFREJ; break; } GETSHORT(cishort, p); GETLONG(cilong, p); LCPDEBUG((LOG_INFO, "(%x %lx)", cishort, cilong)); if (cishort != LQR) { orc = CONFREJ; break; } /* * Check the reporting period. * XXX When should we Nak this, and what with? */ break; case CI_MAGICNUMBER: LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd MAGICNUMBER")); if (!(ao->neg_magicnumber || go->neg_magicnumber) || cilen != CILEN_LONG) { orc = CONFREJ; break; } GETLONG(cilong, p); LCPDEBUG((LOG_INFO, "(%lx)", cilong)); /* * He must have a different magic number. */ if (go->neg_magicnumber && cilong == go->magicnumber) { orc = CONFNAK; DECPTR(sizeof (long), p); cilong = magic(); /* Don't put magic() inside macro! */ PUTLONG(cilong, p); break; } ho->neg_magicnumber = 1; ho->magicnumber = cilong; break; case CI_PCOMPRESSION: LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd PCOMPRESSION")); if (!ao->neg_pcompression || cilen != CILEN_VOID) { orc = CONFREJ; break; } ho->neg_pcompression = 1; break; case CI_ACCOMPRESSION: LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd ACCOMPRESSION")); if (!ao->neg_accompression || cilen != CILEN_VOID) { orc = CONFREJ; break; } ho->neg_accompression = 1; break; default: LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd unknown option %d", citype)); orc = CONFREJ; break; } endswitch: LCPDEBUG((LOG_INFO, " (%s)", CODENAME(orc))); if (orc == CONFACK && /* Good CI */ rc != CONFACK) /* but prior CI wasnt? */ continue; /* Don't send this one */ if (orc == CONFNAK) { /* Nak this CI? */ if (reject_if_disagree) /* Getting fed up with sending NAKs? */ orc = CONFREJ; /* Get tough if so */ else { if (rc == CONFREJ) /* Rejecting prior CI? */ continue; /* Don't send this one */ if (rc == CONFACK) { /* Ack'd all prior CIs? */ rc = CONFNAK; /* Not anymore... */ ucp = inp; /* Backup */ } } } if (orc == CONFREJ && /* Reject this CI */ rc != CONFREJ) { /* but no prior ones? */ rc = CONFREJ; ucp = inp; /* Backup */ } if (ucp != cip) /* Need to move CI? */ BCOPY(cip, ucp, cilen); /* Move it */ INCPTR(cilen, ucp); /* Update output pointer */ } /* * If we wanted to send additional NAKs (for unsent CIs), the * code would go here. This must be done with care since it might * require a longer packet than we received. At present there * are no cases where we want to ask the peer to negotiate an option. */ *lenp = ucp - inp; /* Compute output length */ LCPDEBUG((LOG_INFO, "lcp_reqci: returning CONF%s.", CODENAME(rc))); return (rc); /* Return final code */ } /* * lcp_up - LCP has come UP. * * Start UPAP, IPCP, etc. */ static void lcp_up(f) fsm *f; { lcp_options *wo = &lcp_wantoptions[f->unit]; lcp_options *ho = &lcp_hisoptions[f->unit]; lcp_options *go = &lcp_gotoptions[f->unit]; lcp_options *ao = &lcp_allowoptions[f->unit]; if (!go->neg_magicnumber) go->magicnumber = 0; if (!ho->neg_magicnumber) ho->magicnumber = 0; /* * Set our MTU to the smaller of the MTU we wanted and * the MRU our peer wanted. If we negotiated an MRU, * set our MRU to the larger of value we wanted and * the value we got in the negotiation. */ ppp_send_config(f->unit, MIN(ao->mru, (ho->neg_mru? ho->mru: MTU)), (ho->neg_asyncmap? ho->asyncmap: 0xffffffff), ho->neg_pcompression, ho->neg_accompression); ppp_recv_config(f->unit, (go->neg_mru? MAX(wo->mru, go->mru): MTU), (go->neg_asyncmap? go->asyncmap: 0), go->neg_pcompression, go->neg_accompression); if (ho->neg_mru) peer_mru[f->unit] = ho->mru; ChapLowerUp(f->unit); /* Enable CHAP */ upap_lowerup(f->unit); /* Enable UPAP */ ipcp_lowerup(f->unit); /* Enable IPCP */ lcp_echo_lowerup(f->unit); /* Enable echo messages */ link_established(f->unit); } /* * lcp_down - LCP has gone DOWN. * * Alert other protocols. */ static void lcp_down(f) fsm *f; { lcp_echo_lowerdown(f->unit); ipcp_lowerdown(f->unit); ChapLowerDown(f->unit); upap_lowerdown(f->unit); sifdown(f->unit); ppp_send_config(f->unit, MTU, 0xffffffff, 0, 0); ppp_recv_config(f->unit, MTU, 0x00000000, 0, 0); peer_mru[f->unit] = MTU; link_down(f->unit); } /* * lcp_starting - LCP needs the lower layer up. */ static void lcp_starting(f) fsm *f; { link_required(f->unit); } /* * lcp_finished - LCP has finished with the lower layer. */ static void lcp_finished(f) fsm *f; { link_terminated(f->unit); } /* * lcp_printpkt - print the contents of an LCP packet. */ char *lcp_codenames[] = { "ConfReq", "ConfAck", "ConfNak", "ConfRej", "TermReq", "TermAck", "CodeRej", "ProtRej", "EchoReq", "EchoRep", "DiscReq" }; int lcp_printpkt(p, plen, printer, arg) u_char *p; int plen; void (*printer) __ARGS((void *, char *, ...)); void *arg; { int code, id, len, olen; u_char *pstart, *optend; u_short cishort; u_long cilong; if (plen < HEADERLEN) return 0; pstart = p; GETCHAR(code, p); GETCHAR(id, p); GETSHORT(len, p); if (len < HEADERLEN || len > plen) return 0; if (code >= 1 && code <= sizeof(lcp_codenames) / sizeof(char *)) printer(arg, " %s", lcp_codenames[code-1]); else printer(arg, " code=0x%x", code); printer(arg, " id=0x%x", id); len -= HEADERLEN; switch (code) { case CONFREQ: case CONFACK: case CONFNAK: case CONFREJ: /* print option list */ while (len >= 2) { GETCHAR(code, p); GETCHAR(olen, p); p -= 2; if (olen < 2 || olen > len) { break; } printer(arg, " <"); len -= olen; optend = p + olen; switch (code) { case CI_MRU: if (olen == CILEN_SHORT) { p += 2; GETSHORT(cishort, p); printer(arg, "mru %d", cishort); } break; case CI_ASYNCMAP: if (olen == CILEN_LONG) { p += 2; GETLONG(cilong, p); printer(arg, "asyncmap 0x%x", cilong); } break; case CI_AUTHTYPE: if (olen >= CILEN_SHORT) { p += 2; printer(arg, "auth "); GETSHORT(cishort, p); switch (cishort) { case UPAP: printer(arg, "upap"); break; case CHAP: printer(arg, "chap"); break; default: printer(arg, "0x%x", cishort); } } break; case CI_QUALITY: if (olen >= CILEN_SHORT) { p += 2; printer(arg, "quality "); GETSHORT(cishort, p); switch (cishort) { case LQR: printer(arg, "lqr"); break; default: printer(arg, "0x%x", cishort); } } break; case CI_MAGICNUMBER: if (olen == CILEN_LONG) { p += 2; GETLONG(cilong, p); printer(arg, "magic 0x%x", cilong); } break; case CI_PCOMPRESSION: if (olen == CILEN_VOID) { p += 2; printer(arg, "pcomp"); } break; case CI_ACCOMPRESSION: if (olen == CILEN_VOID) { p += 2; printer(arg, "accomp"); } break; } while (p < optend) { GETCHAR(code, p); printer(arg, " %.2x", code); } printer(arg, ">"); } break; } /* print the rest of the bytes in the packet */ for (; len > 0; --len) { GETCHAR(code, p); printer(arg, " %.2x", code); } return p - pstart; } /* * Time to shut down the link because there is nothing out there. */ static void LcpLinkFailure (f) fsm *f; { if (f->state == OPENED) { syslog (LOG_NOTICE, "Excessive lack of response to LCP echo frames."); lcp_close(f->unit); /* Reset connection */ } } /* * Timer expired for the LCP echo requests from this process. */ static void LcpEchoCheck (f) fsm *f; { u_long delta; LcpSendEchoRequest (f); delta = lcp_echo_interval; /* * Start the timer for the next interval. */ assert (lcp_echo_timer_running==0); TIMEOUT (LcpEchoTimeout, (caddr_t) f, delta); lcp_echo_timer_running = 1; } /* * LcpEchoTimeout - Timer expired on the LCP echo */ static void LcpEchoTimeout (arg) caddr_t arg; { if (lcp_echo_timer_running != 0) { lcp_echo_timer_running = 0; LcpEchoCheck ((fsm *) arg); } } /* * LcpEchoReply - LCP has received a reply to the echo */ static void lcp_received_echo_reply (f, id, inp, len) fsm *f; int id; u_char *inp; int len; { u_long magic; /* Check the magic number - don't count replies from ourselves. */ if (len < CILEN_LONG) return; GETLONG(magic, inp); if (lcp_gotoptions[f->unit].neg_magicnumber && magic == lcp_gotoptions[f->unit].magicnumber) return; /* Reset the number of outstanding echo frames */ lcp_echos_pending = 0; } /* * LcpSendEchoRequest - Send an echo request frame to the peer */ static void LcpSendEchoRequest (f) fsm *f; { u_long lcp_magic; u_char pkt[4], *pktp; /* * Detect the failure of the peer at this point. */ if (lcp_echo_fails != 0) { if (lcp_echos_pending++ >= lcp_echo_fails) { LcpLinkFailure(f); lcp_echos_pending = 0; } } /* * Make and send the echo request frame. */ if (f->state == OPENED) { lcp_magic = lcp_gotoptions[f->unit].neg_magicnumber ? lcp_gotoptions[f->unit].magicnumber : 0L; pktp = pkt; PUTLONG(lcp_magic, pktp); fsm_sdata(f, ECHOREQ, lcp_echo_number++ & 0xFF, pkt, pktp - pkt); } } /* * lcp_echo_lowerup - Start the timer for the LCP frame */ static void lcp_echo_lowerup (unit) int unit; { fsm *f = &lcp_fsm[unit]; /* Clear the parameters for generating echo frames */ lcp_echos_pending = 0; lcp_echo_number = 0; lcp_echo_timer_running = 0; /* If a timeout interval is specified then start the timer */ if (lcp_echo_interval != 0) LcpEchoCheck (f); } /* * lcp_echo_lowerdown - Stop the timer for the LCP frame */ static void lcp_echo_lowerdown (unit) int unit; { fsm *f = &lcp_fsm[unit]; if (lcp_echo_timer_running != 0) { UNTIMEOUT (LcpEchoTimeout, (caddr_t) f); lcp_echo_timer_running = 0; } }