if_spppsubr.c

基于组件方式开发操作系统的OSKIT源代码

	default:
		if (debug)
			addlog(SPP_FMT "cisco unknown packet type: 0x%lx\n",
			       SPP_ARGS(ifp), (u_long)ntohl (h->type));
		break;
	case CISCO_ADDR_REPLY:
		/* Reply on address request, ignore */
		break;
	case CISCO_KEEPALIVE_REQ:
		sp->pp_alivecnt = 0;
		sp->pp_rseq = ntohl (h->par1);
		if (sp->pp_seq == sp->pp_rseq) {
			/* Local and remote sequence numbers are equal.
			 * Probably, the line is in loopback mode. */
			if (sp->pp_loopcnt >= MAXALIVECNT) {
				printf (SPP_FMT "loopback\n",
					SPP_ARGS(ifp));
				sp->pp_loopcnt = 0;
				if (ifp->if_flags & IFF_UP) {
					if_down (ifp);
					sppp_qflush (&sp->pp_cpq);
				}
			}
			++sp->pp_loopcnt;

			/* Generate new local sequence number */
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
			sp->pp_seq = random();
#else
			sp->pp_seq ^= time.tv_sec ^ time.tv_usec;
#endif
			break;
		}
		sp->pp_loopcnt = 0;
		if (! (ifp->if_flags & IFF_UP) &&
		    (ifp->if_flags & IFF_RUNNING)) {
			if_up(ifp);
			printf (SPP_FMT "up\n", SPP_ARGS(ifp));
		}
		break;
	case CISCO_ADDR_REQ:
		sppp_get_ip_addrs(sp, &me, 0, &mymask);
		if (me != 0L)
			sppp_cisco_send(sp, CISCO_ADDR_REPLY, me, mymask);
		break;
	}
}

/*
 * Send Cisco keepalive packet.
 */
static void
sppp_cisco_send(struct sppp *sp, int type, long par1, long par2)
{
	STDDCL;
	struct ppp_header *h;
	struct cisco_packet *ch;
	struct mbuf *m;
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
	struct timeval tv;
#else
	u_long t = (time.tv_sec - boottime.tv_sec) * 1000;
#endif

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
	getmicrouptime(&tv);
#endif
	
	MGETHDR (m, M_DONTWAIT, MT_DATA);
	if (! m)
		return;
	m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + CISCO_PACKET_LEN;
	m->m_pkthdr.rcvif = 0;

	h = mtod (m, struct ppp_header*);
	h->address = CISCO_MULTICAST;
	h->control = 0;
	h->protocol = htons (CISCO_KEEPALIVE);

	ch = (struct cisco_packet*) (h + 1);
	ch->type = htonl (type);
	ch->par1 = htonl (par1);
	ch->par2 = htonl (par2);
	ch->rel = -1;

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
	ch->time0 = htons ((u_short) (tv.tv_sec >> 16));
	ch->time1 = htons ((u_short) tv.tv_sec);
#else
	ch->time0 = htons ((u_short) (t >> 16));
	ch->time1 = htons ((u_short) t);
#endif

	if (debug)
		log(LOG_DEBUG,
		    SPP_FMT "cisco output: <0x%lx 0x%lx 0x%lx 0x%x 0x%x-0x%x>\n",
			SPP_ARGS(ifp), (u_long)ntohl (ch->type), (u_long)ch->par1,
			(u_long)ch->par2, (u_int)ch->rel, (u_int)ch->time0, (u_int)ch->time1);

	if (IF_QFULL (&sp->pp_cpq)) {
		IF_DROP (&sp->pp_fastq);
		IF_DROP (&ifp->if_snd);
		m_freem (m);
	} else
		IF_ENQUEUE (&sp->pp_cpq, m);
	if (! (ifp->if_flags & IFF_OACTIVE))
		(*ifp->if_start) (ifp);
	ifp->if_obytes += m->m_pkthdr.len + 3;
}

/*
 * PPP protocol implementation.
 */

/*
 * Send PPP control protocol packet.
 */
static void
sppp_cp_send(struct sppp *sp, u_short proto, u_char type,
	     u_char ident, u_short len, void *data)
{
	STDDCL;
	struct ppp_header *h;
	struct lcp_header *lh;
	struct mbuf *m;

	if (len > MHLEN - PPP_HEADER_LEN - LCP_HEADER_LEN)
		len = MHLEN - PPP_HEADER_LEN - LCP_HEADER_LEN;
	MGETHDR (m, M_DONTWAIT, MT_DATA);
	if (! m)
		return;
	m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + LCP_HEADER_LEN + len;
	m->m_pkthdr.rcvif = 0;

	h = mtod (m, struct ppp_header*);
	h->address = PPP_ALLSTATIONS;        /* broadcast address */
	h->control = PPP_UI;                 /* Unnumbered Info */
	h->protocol = htons (proto);         /* Link Control Protocol */

	lh = (struct lcp_header*) (h + 1);
	lh->type = type;
	lh->ident = ident;
	lh->len = htons (LCP_HEADER_LEN + len);
	if (len)
		bcopy (data, lh+1, len);

	if (debug) {
		log(LOG_DEBUG, SPP_FMT "%s output <%s id=0x%x len=%d",
		    SPP_ARGS(ifp),
		    sppp_proto_name(proto),
		    sppp_cp_type_name (lh->type), lh->ident,
		    ntohs (lh->len));
		if (len)
			sppp_print_bytes ((u_char*) (lh+1), len);
		addlog(">\n");
	}
	if (IF_QFULL (&sp->pp_cpq)) {
		IF_DROP (&sp->pp_fastq);
		IF_DROP (&ifp->if_snd);
		m_freem (m);
		++ifp->if_oerrors;
	} else
		IF_ENQUEUE (&sp->pp_cpq, m);
	if (! (ifp->if_flags & IFF_OACTIVE))
		(*ifp->if_start) (ifp);
	ifp->if_obytes += m->m_pkthdr.len + 3;
}

/*
 * Handle incoming PPP control protocol packets.
 */
static void
sppp_cp_input(const struct cp *cp, struct sppp *sp, struct mbuf *m)
{
	STDDCL;
	struct lcp_header *h;
	int len = m->m_pkthdr.len;
	int rv;
	u_char *p;

	if (len < 4) {
		if (debug)
			log(LOG_DEBUG,
			    SPP_FMT "%s invalid packet length: %d bytes\n",
			    SPP_ARGS(ifp), cp->name, len);
		return;
	}
	h = mtod (m, struct lcp_header*);
	if (debug) {
		log(LOG_DEBUG,
		    SPP_FMT "%s input(%s): <%s id=0x%x len=%d",
		    SPP_ARGS(ifp), cp->name,
		    sppp_state_name(sp->state[cp->protoidx]),
		    sppp_cp_type_name (h->type), h->ident, ntohs (h->len));
		if (len > 4)
			sppp_print_bytes ((u_char*) (h+1), len-4);
		addlog(">\n");
	}
	if (len > ntohs (h->len))
		len = ntohs (h->len);
	p = (u_char *)(h + 1);
	switch (h->type) {
	case CONF_REQ:
		if (len < 4) {
			if (debug)
				addlog(SPP_FMT "%s invalid conf-req length %d\n",
				       SPP_ARGS(ifp), cp->name,
				       len);
			++ifp->if_ierrors;
			break;
		}
		/* handle states where RCR doesn't get a SCA/SCN */
		switch (sp->state[cp->protoidx]) {
		case STATE_CLOSING:
		case STATE_STOPPING:
			return;
		case STATE_CLOSED:
			sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident,
				     0, 0);
			return;
		}
		rv = (cp->RCR)(sp, h, len);
		switch (sp->state[cp->protoidx]) {
		case STATE_OPENED:
			(cp->tld)(sp);
			(cp->scr)(sp);
			/* fall through... */
		case STATE_ACK_SENT:
		case STATE_REQ_SENT:
			sppp_cp_change_state(cp, sp, rv?
					     STATE_ACK_SENT: STATE_REQ_SENT);
			break;
		case STATE_STOPPED:
			sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
			(cp->scr)(sp);
			sppp_cp_change_state(cp, sp, rv?
					     STATE_ACK_SENT: STATE_REQ_SENT);
			break;
		case STATE_ACK_RCVD:
			if (rv) {
				sppp_cp_change_state(cp, sp, STATE_OPENED);
				if (debug)
					log(LOG_DEBUG, SPP_FMT "%s tlu\n",
					    SPP_ARGS(ifp),
					    cp->name);
				(cp->tlu)(sp);
			} else
				sppp_cp_change_state(cp, sp, STATE_ACK_RCVD);
			break;
		default:
			printf(SPP_FMT "%s illegal %s in state %s\n",
			       SPP_ARGS(ifp), cp->name,
			       sppp_cp_type_name(h->type),
			       sppp_state_name(sp->state[cp->protoidx]));
			++ifp->if_ierrors;
		}
		break;
	case CONF_ACK:
		if (h->ident != sp->confid[cp->protoidx]) {
			if (debug)
				addlog(SPP_FMT "%s id mismatch 0x%x != 0x%x\n",
				       SPP_ARGS(ifp), cp->name,
				       h->ident, sp->confid[cp->protoidx]);
			++ifp->if_ierrors;
			break;
		}
		switch (sp->state[cp->protoidx]) {
		case STATE_CLOSED:
		case STATE_STOPPED:
			sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident, 0, 0);
			break;
		case STATE_CLOSING:
		case STATE_STOPPING:
			break;
		case STATE_REQ_SENT:
			sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
			sppp_cp_change_state(cp, sp, STATE_ACK_RCVD);
			break;
		case STATE_OPENED:
			(cp->tld)(sp);
			/* fall through */
		case STATE_ACK_RCVD:
			(cp->scr)(sp);
			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
			break;
		case STATE_ACK_SENT:
			sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
			sppp_cp_change_state(cp, sp, STATE_OPENED);
			if (debug)
				log(LOG_DEBUG, SPP_FMT "%s tlu\n",
				       SPP_ARGS(ifp), cp->name);
			(cp->tlu)(sp);
			break;
		default:
			printf(SPP_FMT "%s illegal %s in state %s\n",
			       SPP_ARGS(ifp), cp->name,
			       sppp_cp_type_name(h->type),
			       sppp_state_name(sp->state[cp->protoidx]));
			++ifp->if_ierrors;
		}
		break;
	case CONF_NAK:
	case CONF_REJ:
		if (h->ident != sp->confid[cp->protoidx]) {
			if (debug)
				addlog(SPP_FMT "%s id mismatch 0x%x != 0x%x\n",
				       SPP_ARGS(ifp), cp->name,
				       h->ident, sp->confid[cp->protoidx]);
			++ifp->if_ierrors;
			break;
		}
		if (h->type == CONF_NAK)
			(cp->RCN_nak)(sp, h, len);
		else /* CONF_REJ */
			(cp->RCN_rej)(sp, h, len);

		switch (sp->state[cp->protoidx]) {
		case STATE_CLOSED:
		case STATE_STOPPED:
			sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident, 0, 0);
			break;
		case STATE_REQ_SENT:
		case STATE_ACK_SENT:
			sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
			(cp->scr)(sp);
			break;
		case STATE_OPENED:
			(cp->tld)(sp);
			/* fall through */
		case STATE_ACK_RCVD:
			sppp_cp_change_state(cp, sp, STATE_ACK_SENT);
			(cp->scr)(sp);
			break;
		case STATE_CLOSING:
		case STATE_STOPPING:
			break;
		default:
			printf(SPP_FMT "%s illegal %s in state %s\n",
			       SPP_ARGS(ifp), cp->name,
			       sppp_cp_type_name(h->type),
			       sppp_state_name(sp->state[cp->protoidx]));
			++ifp->if_ierrors;
		}
		break;

	case TERM_REQ:
		switch (sp->state[cp->protoidx]) {
		case STATE_ACK_RCVD:
		case STATE_ACK_SENT:
			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
			/* fall through */
		case STATE_CLOSED:
		case STATE_STOPPED:
		case STATE_CLOSING:
		case STATE_STOPPING:
		case STATE_REQ_SENT:
		  sta:
			/* Send Terminate-Ack packet. */
			if (debug)
				log(LOG_DEBUG, SPP_FMT "%s send terminate-ack\n",
				    SPP_ARGS(ifp), cp->name);
			sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident, 0, 0);
			break;
		case STATE_OPENED:
			(cp->tld)(sp);
			sp->rst_counter[cp->protoidx] = 0;
			sppp_cp_change_state(cp, sp, STATE_STOPPING);
			goto sta;
			break;
		default:
			printf(SPP_FMT "%s illegal %s in state %s\n",
			       SPP_ARGS(ifp), cp->name,
			       sppp_cp_type_name(h->type),
			       sppp_state_name(sp->state[cp->protoidx]));
			++ifp->if_ierrors;
		}
		break;
	case TERM_ACK:
		switch (sp->state[cp->protoidx]) {
		case STATE_CLOSED:
		case STATE_STOPPED:
		case STATE_REQ_SENT:
		case STATE_ACK_SENT:
			break;
		case STATE_CLOSING:
			sppp_cp_change_state(cp, sp, STATE_CLOSED);
			(cp->tlf)(sp);
			break;
		case STATE_STOPPING:
			sppp_cp_change_state(cp, sp, STATE_STOPPED);
			(cp->tlf)(sp);
			break;
		case STATE_ACK_RCVD:
			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
			break;
		case STATE_OPENED:
			(cp->tld)(sp);
			(cp->scr)(sp);
			sppp_cp_change_state(cp, sp, STATE_ACK_RCVD);
			break;
		default:
			printf(SPP_FMT "%s illegal %s in state %s\n",
			       SPP_ARGS(ifp), cp->name,
			       sppp_cp_type_name(h->type),
			       sppp_state_name(sp->state[cp->protoidx]));
			++ifp->if_ierrors;
		}
		break;
	case CODE_REJ:
	case PROTO_REJ:
		/* XXX catastrophic rejects (RXJ-) aren't handled yet. */
		log(LOG_INFO,
		    SPP_FMT "%s: ignoring RXJ (%s) for proto 0x%x, "
		    "danger will robinson\n",
		    SPP_ARGS(ifp), cp->name,
		    sppp_cp_type_name(h->type), ntohs(*((u_short *)p)));
		switch (sp->state[cp->protoidx]) {
		case STATE_CLOSED:
		case STATE_STOPPED:
		case STATE_REQ_SENT:
		case STATE_ACK_SENT:
		case STATE_CLOSING:
		case STATE_STOPPING:
		case STATE_OPENED:
			break;
		case STATE_ACK_RCVD:
			sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
			break;
		default:
			printf(SPP_FMT "%s illegal %s in state %s\n",
			       SPP_ARGS(ifp), cp->name,
			       sppp_cp_type_name(h->type),
			       sppp_state_name(sp->state[cp->protoidx]));
			++ifp->if_ierrors;
		}
		break;
	case DISC_REQ:
		if (cp->proto != PPP_LCP)
			goto illegal;
		/* Discard the packet. */
		break;
	case ECHO_REQ:
		if (cp->proto != PPP_LCP)
			goto illegal;
		if (sp->state[cp->protoidx] != STATE_OPENED) {
			if (debug)
				addlog(SPP_FMT "lcp echo req but lcp closed\n",
				       SPP_ARGS(ifp));
			++ifp->if_ierrors;
			break;
		}
		if (len < 8) {
			if (debug)
				addlog(SPP_FMT "invalid lcp echo request "
				       "packet length: %d bytes\n",
				       SPP_ARGS(ifp), len);
			break;
		}
		if (ntohl (*(long*)(h+1)) == sp->lcp.magic) {
			/* Line loopback mode detected. */
			printf(SPP_FMT "loopback\n", SPP_ARGS(ifp));
			if_down (ifp);
			sppp_qflush (&sp->pp_cpq);

			/* Shut down the PPP link. */
			/* XXX */
			lcp.Down(sp);
			lcp.Up(sp);
			break;
		}
		*(long*)(h+1) = htonl (sp->lcp.magic);
		if (debug)
			addlog(SPP_FMT "got lcp echo req, sending echo rep\n",
			       SPP_ARGS(ifp));
		sppp_cp_send (sp, PPP_LCP, ECHO_REPLY, h->ident, len-4, h+1);
		break;
	case ECHO_REPLY:
		if (cp->proto != PPP_LCP)
			goto illegal;
		if (h->ident != sp->lcp.echoid) {
			++ifp->if_ierrors;
			break;
		}
		if (len < 8) {
			if (debug)
				addlog(SPP_FMT "lcp invalid echo reply "
				       "packet length: %d bytes\n",
				       SPP_ARGS(ifp), len);
			break;
		}
		if (debug)
			addlog(SPP_FMT "lcp got echo rep\n",
			       SPP_ARGS(ifp));
		if (ntohl (*(long*)(h+1)) != sp->lcp.magic)
			sp->pp_alivecnt = 0;
		break;
	default:
		/* Unknown packet type -- send Code-Reject packet. */
	  illegal:
		if (debug)
			addlog(SPP_FMT "%s send code-rej for 0x%x\n",
			       SPP_ARGS(ifp), cp->name, h->type);
		sppp_cp_send(sp, cp->proto, CODE_REJ, ++sp->pp_seq,
			     m->m_pkthdr.len, h);
		++ifp->if_ierrors;
	}
}


/*
 * The generic part of all Up/Down/Open/Close/TO event handlers.
 * Basically, the state transition handling in the automaton.
 */
static void
sppp_up_event(const struct cp *cp, struct sppp *sp)
{
	STDDCL;

	if (debug)
		log(LOG_DEBUG, SPP_FMT "%s up(%s)\n",
		    SPP_ARGS(ifp), cp->name,
		    sppp_state_name(sp->state[cp->protoidx]));

	switch (sp->state[cp->protoidx]) {
	case STATE_INITIAL:
		sppp_cp_change_state(cp, sp, STATE_CLOSED);