if_spppsubr.c

基于组件方式开发操作系统的OSKIT源代码

	struct ppp_header *h;
	struct lcp_header *lh;
	struct mbuf *m;
	struct ifnet *ifp = &sp->pp_if;

	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 (ifp->if_flags & IFF_DEBUG) {
		printf ("%s%d: %s output <%s id=%xh len=%xh",
			ifp->if_name, ifp->if_unit,
			proto==PPP_LCP ? "lcp" : "ipcp",
			proto==PPP_LCP ? sppp_lcp_type_name (lh->type) :
			sppp_ipcp_type_name (lh->type), lh->ident,
			ntohs (lh->len));
		if (len)
			sppp_print_bytes ((u_char*) (lh+1), len);
		printf (">\n");
	}
	if (IF_QFULL (&sp->pp_fastq)) {
		IF_DROP (&ifp->if_snd);
		m_freem (m);
	} else
		IF_ENQUEUE (&sp->pp_fastq, m);
	if (! (ifp->if_flags & IFF_OACTIVE))
		(*ifp->if_start) (ifp);
	ifp->if_obytes += m->m_pkthdr.len + 3;
}

/*
 * Send Cisco keepalive packet.
 */
void sppp_cisco_send (struct sppp *sp, int type, long par1, long par2)
{
	struct ppp_header *h;
	struct cisco_packet *ch;
	struct mbuf *m;
	struct ifnet *ifp = &sp->pp_if;
	u_long t = (time.tv_sec - boottime.tv_sec) * 1000;

	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;
	ch->time0 = htons ((u_short) (t >> 16));
	ch->time1 = htons ((u_short) t);

	if (ifp->if_flags & IFF_DEBUG)
		printf ("%s%d: cisco output: <%lxh %lxh %lxh %xh %xh-%xh>\n",
			ifp->if_name, ifp->if_unit, ntohl (ch->type), ch->par1,
			ch->par2, ch->rel, ch->time0, ch->time1);

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

/*
 * Process an ioctl request.  Called on low priority level.
 */
int sppp_ioctl (struct ifnet *ifp, int cmd, void *data)
{
	struct ifreq *ifr = (struct ifreq*) data;
	struct sppp *sp = (struct sppp*) ifp;
	int s, going_up, going_down;

	switch (cmd) {
	default:
		return (EINVAL);

	case SIOCAIFADDR:
	case SIOCSIFDSTADDR:
		break;

	case SIOCSIFADDR:
		ifp->if_flags |= IFF_UP;
		/* fall through... */

	case SIOCSIFFLAGS:
		s = splimp ();
		going_up   = (ifp->if_flags & IFF_UP) &&
			     ! (ifp->if_flags & IFF_RUNNING);
		going_down = ! (ifp->if_flags & IFF_UP) &&
			      (ifp->if_flags & IFF_RUNNING);
		if (going_up || going_down) {
			/* Shut down the PPP link. */
			ifp->if_flags &= ~IFF_RUNNING;
			sp->lcp.state = LCP_STATE_CLOSED;
			sp->ipcp.state = IPCP_STATE_CLOSED;
			UNTIMO (sp);
		}
		if (going_up) {
			/* Interface is starting -- initiate negotiation. */
			ifp->if_flags |= IFF_RUNNING;
			if (!(sp->pp_flags & PP_CISCO))
				sppp_lcp_open (sp);
		}
		splx (s);
		break;

#ifdef SIOCSIFMTU
#ifndef ifr_mtu
#define ifr_mtu ifr_metric
#endif
	case SIOCSIFMTU:
		if (ifr->ifr_mtu < 128 || ifr->ifr_mtu > PP_MTU)
			return (EINVAL);
		ifp->if_mtu = ifr->ifr_mtu;
		break;
#endif
#ifdef SLIOCSETMTU
	case SLIOCSETMTU:
		if (*(short*)data < 128 || *(short*)data > PP_MTU)
			return (EINVAL);
		ifp->if_mtu = *(short*)data;
		break;
#endif
#ifdef SIOCGIFMTU
	case SIOCGIFMTU:
		ifr->ifr_mtu = ifp->if_mtu;
		break;
#endif
#ifdef SLIOCGETMTU
	case SLIOCGETMTU:
		*(short*)data = ifp->if_mtu;
		break;
#endif
#ifdef MULTICAST
	case SIOCADDMULTI:
	case SIOCDELMULTI:
		break;
#endif
	}
	return (0);
}

/*
 * Analyze the LCP Configure-Request options list
 * for the presence of unknown options.
 * If the request contains unknown options, build and
 * send Configure-reject packet, containing only unknown options.
 */
int sppp_lcp_conf_parse_options (struct sppp *sp, struct lcp_header *h,
	int len, u_long *magic)
{
	u_char *buf, *r, *p;
	int rlen;

	len -= 4;
	buf = r = malloc (len, M_TEMP, M_NOWAIT);
	if (! buf)
		return (0);

	p = (void*) (h+1);
	for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
		switch (*p) {
		case LCP_OPT_MAGIC:
			/* Magic number -- extract. */
			if (len >= 6 && p[1] == 6) {
				*magic = (u_long)p[2] << 24 |
					(u_long)p[3] << 16 | p[4] << 8 | p[5];
				continue;
			}
			break;
		case LCP_OPT_ASYNC_MAP:
			/* Async control character map -- check to be zero. */
			if (len >= 6 && p[1] == 6 && ! p[2] && ! p[3] &&
			    ! p[4] && ! p[5])
				continue;
			break;
		case LCP_OPT_MRU:
			/* Maximum receive unit -- always OK. */
			continue;
		default:
			/* Others not supported. */
			break;
		}
		/* Add the option to rejected list. */
			bcopy (p, r, p[1]);
			r += p[1];
		rlen += p[1];
		}
	if (rlen)
	sppp_cp_send (sp, PPP_LCP, LCP_CONF_REJ, h->ident, rlen, buf);
	free (buf, M_TEMP);
	return (rlen == 0);
}

void sppp_ipcp_input (struct sppp *sp, struct mbuf *m)
{
	struct lcp_header *h;
	struct ifnet *ifp = &sp->pp_if;
	int len = m->m_pkthdr.len;

	if (len < 4) {
		/* if (ifp->if_flags & IFF_DEBUG) */
			printf ("%s%d: invalid ipcp packet length: %d bytes\n",
				ifp->if_name, ifp->if_unit, len);
		return;
	}
	h = mtod (m, struct lcp_header*);
	if (ifp->if_flags & IFF_DEBUG) {
		printf ("%s%d: ipcp input: %d bytes <%s id=%xh len=%xh",
			ifp->if_name, ifp->if_unit, len,
			sppp_ipcp_type_name (h->type), h->ident, ntohs (h->len));
		if (len > 4)
			sppp_print_bytes ((u_char*) (h+1), len-4);
		printf (">\n");
	}
	if (len > ntohs (h->len))
		len = ntohs (h->len);
	switch (h->type) {
	default:
		/* Unknown packet type -- send Code-Reject packet. */
		sppp_cp_send (sp, PPP_IPCP, IPCP_CODE_REJ, ++sp->pp_seq, len, h);
		break;
	case IPCP_CONF_REQ:
		if (len < 4) {
			if (ifp->if_flags & IFF_DEBUG)
				printf ("%s%d: invalid ipcp configure request packet length: %d bytes\n",
					ifp->if_name, ifp->if_unit, len);
			return;
		}
		if (len > 4) {
			sppp_cp_send (sp, PPP_IPCP, LCP_CONF_REJ, h->ident,
				len-4, h+1);

			switch (sp->ipcp.state) {
			case IPCP_STATE_OPENED:
				/* Initiate renegotiation. */
				sppp_ipcp_open (sp);
				/* fall through... */
			case IPCP_STATE_ACK_SENT:
				/* Go to closed state. */
				sp->ipcp.state = IPCP_STATE_CLOSED;
			}
		} else {
			/* Send Configure-Ack packet. */
			sppp_cp_send (sp, PPP_IPCP, IPCP_CONF_ACK, h->ident,
				0, 0);
			/* Change the state. */
			if (sp->ipcp.state == IPCP_STATE_ACK_RCVD)
				sp->ipcp.state = IPCP_STATE_OPENED;
			else
				sp->ipcp.state = IPCP_STATE_ACK_SENT;
		}
		break;
	case IPCP_CONF_ACK:
		if (h->ident != sp->ipcp.confid)
			break;
		UNTIMO (sp);
		switch (sp->ipcp.state) {
		case IPCP_STATE_CLOSED:
			sp->ipcp.state = IPCP_STATE_ACK_RCVD;
			TIMO (sp, 5);
			break;
		case IPCP_STATE_ACK_SENT:
			sp->ipcp.state = IPCP_STATE_OPENED;
			break;
		}
		break;
	case IPCP_CONF_NAK:
	case IPCP_CONF_REJ:
		if (h->ident != sp->ipcp.confid)
			break;
		UNTIMO (sp);
			/* Initiate renegotiation. */
			sppp_ipcp_open (sp);
		if (sp->ipcp.state != IPCP_STATE_ACK_SENT)
			/* Go to closed state. */
			sp->ipcp.state = IPCP_STATE_CLOSED;
		break;
	case IPCP_TERM_REQ:
		/* Send Terminate-Ack packet. */
		sppp_cp_send (sp, PPP_IPCP, IPCP_TERM_ACK, h->ident, 0, 0);
		/* Go to closed state. */
		sp->ipcp.state = IPCP_STATE_CLOSED;
			/* Initiate renegotiation. */
			sppp_ipcp_open (sp);
		break;
	case IPCP_TERM_ACK:
		/* Ignore for now. */
	case IPCP_CODE_REJ:
		/* Ignore for now. */
		break;
	}
}

void sppp_lcp_open (struct sppp *sp)
{
	char opt[6];

	if (! sp->lcp.magic)
	sp->lcp.magic = time.tv_sec + time.tv_usec;
	opt[0] = LCP_OPT_MAGIC;
	opt[1] = sizeof (opt);
	opt[2] = sp->lcp.magic >> 24;
	opt[3] = sp->lcp.magic >> 16;
	opt[4] = sp->lcp.magic >> 8;
	opt[5] = sp->lcp.magic;
	sp->lcp.confid = ++sp->pp_seq;
	sppp_cp_send (sp, PPP_LCP, LCP_CONF_REQ, sp->lcp.confid,
		sizeof (opt), &opt);
	TIMO (sp, 2);
}

void sppp_ipcp_open (struct sppp *sp)
{
	sp->ipcp.confid = ++sp->pp_seq;
	sppp_cp_send (sp, PPP_IPCP, IPCP_CONF_REQ, sp->ipcp.confid, 0, 0);
	TIMO (sp, 2);
}

/*
 * Process PPP control protocol timeouts.
 */
void sppp_cp_timeout (void *arg)
{
	struct sppp *sp = (struct sppp*) arg;
	int s = splimp ();

	sp->pp_flags &= ~PP_TIMO;
	if (! (sp->pp_if.if_flags & IFF_RUNNING) || (sp->pp_flags & PP_CISCO)) {
		splx (s);
		return;
	}
	switch (sp->lcp.state) {
	case LCP_STATE_CLOSED:
		/* No ACK for Configure-Request, retry. */
		sppp_lcp_open (sp);
		break;
	case LCP_STATE_ACK_RCVD:
		/* ACK got, but no Configure-Request for peer, retry. */
		sppp_lcp_open (sp);
		sp->lcp.state = LCP_STATE_CLOSED;
		break;
	case LCP_STATE_ACK_SENT:
		/* ACK sent but no ACK for Configure-Request, retry. */
		sppp_lcp_open (sp);
		break;
	case LCP_STATE_OPENED:
		/* LCP is already OK, try IPCP. */
		switch (sp->ipcp.state) {
		case IPCP_STATE_CLOSED:
			/* No ACK for Configure-Request, retry. */
			sppp_ipcp_open (sp);
			break;
		case IPCP_STATE_ACK_RCVD:
			/* ACK got, but no Configure-Request for peer, retry. */
			sppp_ipcp_open (sp);
			sp->ipcp.state = IPCP_STATE_CLOSED;
			break;
		case IPCP_STATE_ACK_SENT:
			/* ACK sent but no ACK for Configure-Request, retry. */
			sppp_ipcp_open (sp);
			break;
		case IPCP_STATE_OPENED:
			/* IPCP is OK. */
			break;
		}
		break;
	}
	splx (s);
}

char *sppp_lcp_type_name (u_char type)
{
	static char buf [8];
	switch (type) {
	case LCP_CONF_REQ:   return ("conf-req");
	case LCP_CONF_ACK:   return ("conf-ack");
	case LCP_CONF_NAK:   return ("conf-nack");
	case LCP_CONF_REJ:   return ("conf-rej");
	case LCP_TERM_REQ:   return ("term-req");
	case LCP_TERM_ACK:   return ("term-ack");
	case LCP_CODE_REJ:   return ("code-rej");
	case LCP_PROTO_REJ:  return ("proto-rej");
	case LCP_ECHO_REQ:   return ("echo-req");
	case LCP_ECHO_REPLY: return ("echo-reply");
	case LCP_DISC_REQ:   return ("discard-req");
	}
	sprintf (buf, "%xh", type);
	return (buf);
}

char *sppp_ipcp_type_name (u_char type)
{
	static char buf [8];
	switch (type) {
	case IPCP_CONF_REQ:   return ("conf-req");
	case IPCP_CONF_ACK:   return ("conf-ack");
	case IPCP_CONF_NAK:   return ("conf-nack");
	case IPCP_CONF_REJ:   return ("conf-rej");
	case IPCP_TERM_REQ:   return ("term-req");
	case IPCP_TERM_ACK:   return ("term-ack");
	case IPCP_CODE_REJ:   return ("code-rej");
	}
	sprintf (buf, "%xh", type);
	return (buf);
}

void sppp_print_bytes (u_char *p, u_short len)
{
	printf (" %x", *p++);
	while (--len > 0)
		printf ("-%x", *p++);
}