ipcpin.c

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/*
 * Copyright (C) 2001-2004 by egnite Software GmbH. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY EGNITE SOFTWARE GMBH AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL EGNITE
 * SOFTWARE GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * For additional information see http://www.ethernut.de/
 *
 * -
 * Portions are 
 * Copyright (c) 1989 by 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.
 */

/*
 * $Log$
 * Revision 1.8  2008/08/11 07:00:30  haraldkipp
 * BSD types replaced by stdint types (feature request #1282721).
 *
 * Revision 1.7  2005/04/08 15:20:50  olereinhardt
 * added <sys/types.h> (__APPLE__) and <netinet/in.h> (__linux__)
 * for htons and simmilar.
 *
 * Revision 1.6  2004/03/08 11:24:48  haraldkipp
 * PppUp() replaced by direct post.
 *
 * Revision 1.5  2004/01/30 11:36:52  haraldkipp
 * Memory hole fixed
 *
 * Revision 1.4  2003/12/18 20:44:11  drsung
 * Bug fix in IpcpRxConfReq. Thanks to Michel Hendriks.
 *
 * Revision 1.3  2003/08/14 15:17:50  haraldkipp
 * Caller controls ID increment
 *
 * Revision 1.2  2003/07/24 16:12:53  haraldkipp
 * First bugfix: PPP always used the secondary DNS.
 * Second bugfix: When the PPP server rejects the
 * secondary DNS, IPCP negotiation was trapped in a
 * loop.
 *
 * Revision 1.1.1.1  2003/05/09 14:41:30  haraldkipp
 * Initial using 3.2.1
 *
 * Revision 1.2  2003/05/06 18:04:57  harald
 * PPP IP config to DCB
 *
 * Revision 1.1  2003/03/31 14:53:27  harald
 * Prepare release 3.1
 *
 */

#include <sys/event.h>
#include <sys/types.h>
#include <net/if_var.h>
#include <dev/ppp.h>

#include <netinet/if_ppp.h>
#include <netinet/ppp_fsm.h>
#include <netinet/in.h>

/*
 * Received Configure-Request.
 */
void IpcpRxConfReq(NUTDEVICE * dev, uint8_t id, NETBUF * nb)
{
    PPPDCB *dcb = dev->dev_dcb;
    int rc = XCP_CONFACK;
    XCPOPT *xcpo;
    uint16_t xcpl;
    XCPOPT *xcpr;
    uint16_t xcps;
    uint16_t len = 0;
    uint_fast8_t i;

    switch (dcb->dcb_ipcp_state) {
    case PPPS_CLOSED:
        /*
         * Go away, we're closed. 
         */
        NutNetBufFree(nb);
        NutIpcpOutput(dev, XCP_TERMACK, id, 0);
        return;

    case PPPS_CLOSING:
    case PPPS_STOPPING:
        /*
         * Ignore if we are going down.
         */
        NutNetBufFree(nb);
        return;

    case PPPS_OPENED:
        /* 
         * Go down and restart negotiation.
         */
        IpcpLowerDown(dev);
        IpcpTxConfReq(dev, ++dcb->dcb_reqid);
        break;

    case PPPS_STOPPED:
        /* 
         * Negotiation started by our peer.
         */
        IpcpTxConfReq(dev, ++dcb->dcb_reqid);
        dcb->dcb_ipcp_state = PPPS_REQSENT;
        break;
    }

    /*
     * Check if there is anything to reject.
     */
    xcpo = nb->nb_ap.vp;
    xcpl = nb->nb_ap.sz;
    xcpr = nb->nb_ap.vp;
    xcps = 0;
    while (xcpl >= 2) {
        len = xcpo->xcpo_len;
        if (len > xcpl)
            len = xcpl;
        else {
            switch (xcpo->xcpo_type) {
            case IPCP_COMPRESSTYPE:
                break;
            case IPCP_ADDR:
            case IPCP_MS_DNS1:
            case IPCP_MS_DNS2:
                if (xcpo->xcpo_len == 6)
                    len = 0;
                break;
            }
        }

        if (len) {
            if (xcpr != xcpo) {
                xcpr->xcpo_type = xcpo->xcpo_type;
                xcpr->xcpo_len = len;
                for (i = 0; i < len - 2; i++)
                    /* bug fix by Michel Hendriks. Thanks! */
                    xcpr->xcpo_.uc[i] = xcpo->xcpo_.uc[i];
            }
            xcpr = (XCPOPT *) ((char *) xcpr + len);
            xcps += len;
        }
        xcpl -= xcpo->xcpo_len;
        xcpo = (XCPOPT *) ((char *) xcpo + xcpo->xcpo_len);
    }

    if (xcps) {
        nb->nb_ap.sz = xcps;
        rc = XCP_CONFREJ;
    }

    /*
     * Check if there is anything to negotiate.
     */
    else {
        xcpo = nb->nb_ap.vp;
        xcpl = nb->nb_ap.sz;
        xcpr = nb->nb_ap.vp;
        xcps = 0;
        len = 0;
        while (xcpl >= 2) {
            switch (xcpo->xcpo_type) {
            case IPCP_ADDR:
                if (xcpo->xcpo_.ul)
                    dcb->dcb_remote_ip = xcpo->xcpo_.ul;
                else if (dcb->dcb_remote_ip == 0)
                    len = xcpo->xcpo_len;
                break;
            case IPCP_COMPRESSTYPE:
                len = 6;
                xcpr->xcpo_.ul = 0;
                break;
            case IPCP_MS_DNS1:
                if (xcpo->xcpo_.ul)
                    dcb->dcb_ip_dns1 = xcpo->xcpo_.ul;
                break;
            case IPCP_MS_DNS2:
                if (xcpo->xcpo_.ul)
                    dcb->dcb_ip_dns2 = xcpo->xcpo_.ul;
                break;
            }

            if (len) {
                if (xcpr != xcpo) {
                    xcpr->xcpo_type = xcpo->xcpo_type;
                    xcpr->xcpo_len = len;
                }
                xcpr = (XCPOPT *) ((char *) xcpr + len);
                xcps += len;
                len = 0;
            }
            xcpl -= xcpo->xcpo_len;
            xcpo = (XCPOPT *) ((char *) xcpo + xcpo->xcpo_len);
        }
        if (xcps) {
            nb->nb_ap.sz = xcps;
            rc = XCP_CONFNAK;
        }
    }

    NutIpcpOutput(dev, rc, id, nb);

    if (rc == XCP_CONFACK) {
        if (dcb->dcb_ipcp_state == PPPS_ACKRCVD) {
            dcb->dcb_ipcp_state = PPPS_OPENED;
            NutEventPost(&dcb->dcb_state_chg);
        } else
            dcb->dcb_ipcp_state = PPPS_ACKSENT;
        dcb->dcb_ipcp_naks = 0;
    } else if (dcb->dcb_ipcp_state != PPPS_ACKRCVD)
        dcb->dcb_ipcp_state = PPPS_REQSENT;
}

/*
 * Configure-Ack received.
 */
void IpcpRxConfAck(NUTDEVICE * dev, uint8_t id, NETBUF * nb)
{
    PPPDCB *dcb = dev->dev_dcb;
    XCPOPT *xcpo;
    uint16_t xcpl;

    /*
     * Ignore, if we are not expecting this id.
     */
    if (id != dcb->dcb_reqid || dcb->dcb_acked) {
        return;
    }

    switch (dcb->dcb_ipcp_state) {
    case PPPS_CLOSED:
    case PPPS_STOPPED:
        /*
         * Go away, we're closed. 
         */
        NutNetBufFree(nb);
        NutIpcpOutput(dev, XCP_TERMACK, id, 0);
        return;

    case PPPS_REQSENT:
        dcb->dcb_ipcp_state = PPPS_ACKRCVD;
        dcb->dcb_retries = 0;
        break;

    case PPPS_ACKRCVD:
        /* Huh? an extra valid Ack? oh well... */
        IpcpTxConfReq(dev, ++dcb->dcb_reqid);
        dcb->dcb_ipcp_state = PPPS_REQSENT;
        break;

    case PPPS_ACKSENT:
        dcb->dcb_ipcp_state = PPPS_OPENED;
        dcb->dcb_retries = 0;
        NutEventPost(&dcb->dcb_state_chg);
        break;

    case PPPS_OPENED:
        /* Go down and restart negotiation */
        IpcpLowerDown(dev);
        IpcpTxConfReq(dev, ++dcb->dcb_reqid);
        dcb->dcb_ipcp_state = PPPS_REQSENT;
        break;
    }

    xcpo = nb->nb_ap.vp;
    xcpl = nb->nb_ap.sz;
    while (xcpl >= 2) {
        switch (xcpo->xcpo_type) {
        case IPCP_ADDR:
            if (xcpo->xcpo_.ul)
                dcb->dcb_local_ip = xcpo->xcpo_.ul;
            break;
        case IPCP_COMPRESSTYPE:
            break;
        case IPCP_MS_DNS1:
            if (xcpo->xcpo_.ul)
                dcb->dcb_ip_dns1 = xcpo->xcpo_.ul;
            break;
        case IPCP_MS_DNS2:
            /* Fixed secondary DNS bug, thanks to Tarmo Fimberg
               and Jelle Martijn Kok. */
            if (xcpo->xcpo_.ul)
                dcb->dcb_ip_dns2 = xcpo->xcpo_.ul;
            break;
        }
        xcpl -= xcpo->xcpo_len;
        xcpo = (XCPOPT *) ((char *) xcpo + xcpo->xcpo_len);
    }

    dcb->dcb_acked = 1;
    NutNetBufFree(nb);
}

/*
 * Configure-Nak or Configure-Reject received.
 */
static void IpcpRxConfNakRej(NUTDEVICE * dev, uint8_t id, NETBUF * nb, uint8_t rejected)
{
    PPPDCB *dcb = dev->dev_dcb;
    XCPOPT *xcpo;
    uint16_t xcpl;

    /*
     * Ignore, if we are not expecting this id.
     */
    if (id != dcb->dcb_reqid || dcb->dcb_acked) {
        NutNetBufFree(nb);
        return;
    }

    switch (dcb->dcb_ipcp_state) {
    case PPPS_CLOSED:
    case PPPS_STOPPED:
        /*
         * Go away, we're closed. 
         */
        NutNetBufFree(nb);
        NutIpcpOutput(dev, XCP_TERMACK, id, 0);
        return;

    case PPPS_REQSENT:
    case PPPS_ACKSENT:
    case PPPS_ACKRCVD:
    case PPPS_OPENED:
        break;

    default:
        NutNetBufFree(nb);
        return;
    }

    dcb->dcb_acked = 1;

    xcpo = nb->nb_ap.vp;
    xcpl = nb->nb_ap.sz;
    while (xcpl >= 2) {
        switch (xcpo->xcpo_type) {
        case IPCP_ADDR:
            if (xcpo->xcpo_.ul)
                dcb->dcb_local_ip = xcpo->xcpo_.ul;
            break;
        case IPCP_COMPRESSTYPE:
            break;
        case IPCP_MS_DNS1:
            if (rejected)
                dcb->dcb_rejects |= REJ_IPCP_DNS1;
            else if (xcpo->xcpo_.ul)
                dcb->dcb_ip_dns1 = xcpo->xcpo_.ul;
            break;
        case IPCP_MS_DNS2:
            if (rejected)
                dcb->dcb_rejects |= REJ_IPCP_DNS2;
            else if (xcpo->xcpo_.ul)
                dcb->dcb_ip_dns2 = xcpo->xcpo_.ul;
            break;
        }
        xcpl -= xcpo->xcpo_len;
        xcpo = (XCPOPT *) ((char *) xcpo + xcpo->xcpo_len);
    }
    NutNetBufFree(nb);

    switch (dcb->dcb_ipcp_state) {

    case PPPS_REQSENT:
    case PPPS_ACKSENT:
        /* They didn't agree to what we wanted - try another request */
        IpcpTxConfReq(dev, ++dcb->dcb_reqid);
        break;

    case PPPS_ACKRCVD:
        /* Got a Nak/reject when we had already had an Ack?? oh well... */
        IpcpTxConfReq(dev, ++dcb->dcb_reqid);
        dcb->dcb_ipcp_state = PPPS_REQSENT;
        break;

    case PPPS_OPENED:
        /* Go down and restart negotiation */
        IpcpLowerDown(dev);
        IpcpTxConfReq(dev, ++dcb->dcb_reqid);
        dcb->dcb_ipcp_state = PPPS_REQSENT;
        break;
    }
}

/*
 * \brief Terminate request received.
 */
void IpcpRxTermReq(NUTDEVICE * dev, uint8_t id, NETBUF * nb)
{
    PPPDCB *dcb = dev->dev_dcb;

    NutNetBufFree(nb);
    switch (dcb->dcb_ipcp_state) {
    case PPPS_ACKRCVD:
    case PPPS_ACKSENT:
        dcb->dcb_ipcp_state = PPPS_REQSENT;
        break;

    case PPPS_OPENED:
        IpcpLowerDown(dev);
        dcb->dcb_ipcp_state = PPPS_STOPPING;
        break;
    }
    NutIpcpOutput(dev, XCP_TERMACK, id, 0);
}

/*
 * Terminate-Ack received.
 */
void IpcpRxTermAck(NUTDEVICE * dev, uint8_t id, NETBUF * nb)
{
    PPPDCB *dcb = dev->dev_dcb;

    switch (dcb->dcb_ipcp_state) {
    case PPPS_CLOSING:
        dcb->dcb_ipcp_state = PPPS_CLOSED;
        break;
    case PPPS_STOPPING:
        dcb->dcb_ipcp_state = PPPS_STOPPED;
        break;

    case PPPS_ACKRCVD:
        dcb->dcb_ipcp_state = PPPS_REQSENT;
        break;

    case PPPS_OPENED:
        IpcpLowerDown(dev);
        IpcpTxConfReq(dev, ++dcb->dcb_reqid);
        break;
    }
}

/*
 * Peer doesn't speak this protocol.
 *
 * Treat this as a catastrophic error (RXJ-).
 */
void IpcpRxProtRej(NUTDEVICE * dev)
{
    PPPDCB *dcb = dev->dev_dcb;

    switch (dcb->dcb_ipcp_state) {
    case PPPS_CLOSING:
    case PPPS_CLOSED:
        dcb->dcb_ipcp_state = PPPS_CLOSED;
        break;

    case PPPS_STOPPING:
    case PPPS_REQSENT:
    case PPPS_ACKRCVD:
    case PPPS_ACKSENT:
    case PPPS_STOPPED:
        dcb->dcb_ipcp_state = PPPS_STOPPED;
        break;

    case PPPS_OPENED:
        IpcpLowerDown(dev);
        NutIpcpOutput(dev, XCP_TERMREQ, dcb->dcb_reqid, 0);
        dcb->dcb_ipcp_state = PPPS_STOPPING;
        break;
    }
}

/*
 * Receive an Code-Reject.
 */
static void IpcpRxCodeRej(NUTDEVICE * dev, uint8_t id, NETBUF * nb)
{
    PPPDCB *dcb = dev->dev_dcb;

    NutNetBufFree(nb);
    if (dcb->dcb_ipcp_state == PPPS_ACKRCVD)
        dcb->dcb_ipcp_state = PPPS_REQSENT;
}



void NutIpcpInput(NUTDEVICE * dev, NETBUF * nb)
{
    XCPHDR *xch;
    PPPDCB *dcb = dev->dev_dcb;
    uint16_t len;

    /*
     * Discard packets with illegal lengths.
     */
    if (nb->nb_nw.sz < sizeof(XCPHDR)) {
        NutNetBufFree(nb);
        return;
    }
    xch = (XCPHDR *) nb->nb_nw.vp;
    if ((len = htons(xch->xch_len)) < sizeof(XCPHDR) || len > nb->nb_nw.sz) {
        NutNetBufFree(nb);
        return;
    }

    /*
     * Discard all packets while we are in initial or starting state.
     */
    if (dcb->dcb_ipcp_state == PPPS_INITIAL || dcb->dcb_ipcp_state == PPPS_STARTING) {
        NutNetBufFree(nb);
        return;
    }

    /*
     * Split the IPCP packet.
     */
    nb->nb_ap.vp = xch + 1;
    nb->nb_ap.sz = htons(xch->xch_len) - sizeof(XCPHDR);

    /*
     * Action depends on code.
     */
    switch (xch->xch_code) {
    case XCP_CONFREQ:
        IpcpRxConfReq(dev, xch->xch_id, nb);
        break;

    case XCP_CONFACK:
        IpcpRxConfAck(dev, xch->xch_id, nb);
        break;

    case XCP_CONFNAK:
        IpcpRxConfNakRej(dev, xch->xch_id, nb, 0);
        break;

    case XCP_CONFREJ:
        IpcpRxConfNakRej(dev, xch->xch_id, nb, 1);
        break;

    case XCP_TERMREQ:
        IpcpRxTermReq(dev, xch->xch_id, nb);
        break;

    case XCP_TERMACK:
        IpcpRxTermAck(dev, xch->xch_id, nb);
        break;

    case XCP_CODEREJ:
        IpcpRxCodeRej(dev, xch->xch_id, nb);
        break;

    default:
        /*
         * TODO: Send code reject.
         */
        NutNetBufFree(nb);
        break;
    }
}