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#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "../port/error.h"

#include "../port/netif.h"
#include "ip.h"
#include "ipv6.h"

typedef struct Etherhdr Etherhdr;
struct Etherhdr
{
        uchar   d[6];
        uchar   s[6];
        uchar   t[2];
};

static uchar ipbroadcast[IPaddrlen] = {
        0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,
        0xff,0xff,0xff,0xff,
};

static uchar etherbroadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };

static void     etherread4(void *a);
static void     etherread6(void *a);
static void     etherbind(Ipifc *ifc, int argc, char **argv);
static void     etherunbind(Ipifc *ifc);
static void     etherbwrite(Ipifc *ifc, Block *bp, int version, uchar *ip);
static void     etheraddmulti(Ipifc *ifc, uchar *a, uchar *ia);
static void     etherremmulti(Ipifc *ifc, uchar *a, uchar *ia);
static Block*   multicastarp(Fs *f, Arpent *a, Medium*, uchar *mac);
static void     sendarp(Ipifc *ifc, Arpent *a);
static void     sendgarp(Ipifc *ifc, uchar*);
static int      multicastea(uchar *ea, uchar *ip);
static void     recvarpproc(void*);
static void     resolveaddr6(Ipifc *ifc, Arpent *a);
static void     etherpref2addr(uchar *pref, uchar *ea);

Medium ethermedium =
{
.name=          "ether",
.hsize=         14,
.mintu=         60,
.maxtu=         1514,
.maclen=        6,
.bind=          etherbind,
.unbind=        etherunbind,
.bwrite=        etherbwrite,
.addmulti=      etheraddmulti,
.remmulti=      etherremmulti,
.ares=          arpenter,
.areg=          sendgarp,
.pref2addr=     etherpref2addr,
};

Medium gbemedium =
{
.name=          "gbe",
.hsize=         14,
.mintu=         60,
.maxtu=         9014,
.maclen=        6,
.bind=          etherbind,
.unbind=        etherunbind,
.bwrite=        etherbwrite,
.addmulti=      etheraddmulti,
.remmulti=      etherremmulti,
.ares=          arpenter,
.areg=          sendgarp,
.pref2addr=     etherpref2addr,
};

typedef struct  Etherrock Etherrock;
struct Etherrock
{
        Fs      *f;             /* file system we belong to */
        Proc    *arpp;          /* arp process */
        Proc    *read4p;        /* reading process (v4)*/
        Proc    *read6p;        /* reading process (v6)*/
        Chan    *mchan4;        /* Data channel for v4 */
        Chan    *achan;         /* Arp channel */
        Chan    *cchan4;        /* Control channel for v4 */
        Chan    *mchan6;        /* Data channel for v6 */
        Chan    *cchan6;        /* Control channel for v6 */
};

/*
 *  ethernet arp request
 */
enum
{
        ARPREQUEST      = 1,
        ARPREPLY        = 2,
};

typedef struct Etherarp Etherarp;
struct Etherarp
{
        uchar   d[6];
        uchar   s[6];
        uchar   type[2];
        uchar   hrd[2];
        uchar   pro[2];
        uchar   hln;
        uchar   pln;
        uchar   op[2];
        uchar   sha[6];
        uchar   spa[4];
        uchar   tha[6];
        uchar   tpa[4];
};

static char *nbmsg = "nonblocking";

/*
 *  called to bind an IP ifc to an ethernet device
 *  called with ifc wlock'd
 */
static void
etherbind(Ipifc *ifc, int argc, char **argv)
{
        Chan *mchan4, *cchan4, *achan, *mchan6, *cchan6, *schan;
        char addr[Maxpath];     //char addr[2*KNAMELEN];
        char dir[Maxpath];      //char dir[2*KNAMELEN];
        char *buf;
        int n;
        char *ptr;
        Etherrock *er;

        if(argc < 2)
                error(Ebadarg);

        mchan4 = cchan4 = achan = mchan6 = cchan6 = nil;
        buf = nil;
        if(waserror()){
                if(mchan4 != nil)
                        cclose(mchan4);
                if(cchan4 != nil)
                        cclose(cchan4);
                if(achan != nil)
                        cclose(achan);
                if(mchan6 != nil)
                        cclose(mchan6);
                if(cchan6 != nil)
                        cclose(cchan6);
                if(buf != nil)
                        free(buf);
                nexterror();
        }

        /*
         *  open ipv4 conversation
         *
         *  the dial will fail if the type is already open on
         *  this device.
         */
        snprint(addr, sizeof(addr), "%s!0x800", argv[2]);       /* ETIP4 */
        mchan4 = chandial(addr, nil, dir, &cchan4);

        /*
         *  make it non-blocking
         */
        devtab[cchan4->type]->write(cchan4, nbmsg, strlen(nbmsg), 0);

        /*
         *  get mac address and speed
         */
        snprint(addr, sizeof(addr), "%s/stats", argv[2]);
        buf = smalloc(512);
        schan = namec(addr, Aopen, OREAD, 0);
        if(waserror()){
                cclose(schan);
                nexterror();
        }
        n = devtab[schan->type]->read(schan, buf, 511, 0);
        cclose(schan);
        poperror();
        buf[n] = 0;

        ptr = strstr(buf, "addr: ");
        if(!ptr)
                error(Eio);
        ptr += 6;
        parsemac(ifc->mac, ptr, 6);

        ptr = strstr(buf, "mbps: ");
        if(ptr){
                ptr += 6;
                ifc->mbps = atoi(ptr);
        } else
                ifc->mbps = 100;

        /*
         *  open arp conversation
         */
        snprint(addr, sizeof(addr), "%s!0x806", argv[2]);       /* ETARP */
        achan = chandial(addr, nil, nil, nil);

        /*
         *  open ipv6 conversation
         *
         *  the dial will fail if the type is already open on
         *  this device.
         */
        snprint(addr, sizeof(addr), "%s!0x86DD", argv[2]);      /* ETIP6 */
        mchan6 = chandial(addr, nil, dir, &cchan6);

        /*
         *  make it non-blocking
         */
        devtab[cchan6->type]->write(cchan6, nbmsg, strlen(nbmsg), 0);

        er = smalloc(sizeof(*er));
        er->mchan4 = mchan4;
        er->cchan4 = cchan4;
        er->achan = achan;
        er->mchan6 = mchan6;
        er->cchan6 = cchan6;
        er->f = ifc->conv->p->f;
        ifc->arg = er;

        free(buf);
        poperror();

        kproc("etherread4", etherread4, ifc);
        kproc("recvarpproc", recvarpproc, ifc);
        kproc("etherread6", etherread6, ifc);
}

/*
 *  called with ifc wlock'd
 */
static void
etherunbind(Ipifc *ifc)
{
        Etherrock *er = ifc->arg;

        if(er->read4p)
                postnote(er->read4p, 1, "unbind", 0);
        if(er->read6p)
                postnote(er->read6p, 1, "unbind", 0);
        if(er->arpp)
                postnote(er->arpp, 1, "unbind", 0);

        /* wait for readers to die */
        while(er->arpp != 0 || er->read4p != 0 || er->read6p != 0)
                tsleep(&up->sleep, return0, 0, 300);

        if(er->mchan4 != nil)
                cclose(er->mchan4);
        if(er->achan != nil)
                cclose(er->achan);
        if(er->cchan4 != nil)
                cclose(er->cchan4);
        if(er->mchan6 != nil)
                cclose(er->mchan6);
        if(er->cchan6 != nil)
                cclose(er->cchan6);

        free(er);
}

/*
 *  called by ipoput with a single block to write with ifc rlock'd
 */
static void
etherbwrite(Ipifc *ifc, Block *bp, int version, uchar *ip)
{
        Etherhdr *eh;
        Arpent *a;
        uchar mac[6];
        Etherrock *er = ifc->arg;

        /* get mac address of destination */
        a = arpget(er->f->arp, bp, version, ifc, ip, mac);
        if(a){
                /* check for broadcast or multicast */
                bp = multicastarp(er->f, a, ifc->m, mac);
                if(bp==nil){
                        switch(version){
                        case V4:
                                sendarp(ifc, a);
                                break;
                        case V6:
                                resolveaddr6(ifc, a);
                                break;
                        default:
                                panic("etherbwrite: version %d", version);
                        }
                        return;
                }
        }

        /* make it a single block with space for the ether header */
        bp = padblock(bp, ifc->m->hsize);
        if(bp->next)
                bp = concatblock(bp);
        if(BLEN(bp) < ifc->mintu)
                bp = adjustblock(bp, ifc->mintu);
        eh = (Etherhdr*)bp->rp;

        /* copy in mac addresses and ether type */
        memmove(eh->s, ifc->mac, sizeof(eh->s));
        memmove(eh->d, mac, sizeof(eh->d));

        switch(version){
        case V4:
                eh->t[0] = 0x08;
                eh->t[1] = 0x00;
                devtab[er->mchan4->type]->bwrite(er->mchan4, bp, 0);
                break;
        case V6:
                eh->t[0] = 0x86;
                eh->t[1] = 0xDD;
                devtab[er->mchan6->type]->bwrite(er->mchan6, bp, 0);
                break;
        default:
                panic("etherbwrite2: version %d", version);
        }
        ifc->out++;
}


/*
 *  process to read from the ethernet
 */
static void
etherread4(void *a)
{
        Ipifc *ifc;
        Block *bp;
        Etherrock *er;

        ifc = a;
        er = ifc->arg;
        er->read4p = up;        /* hide identity under a rock for unbind */
        if(waserror()){
                er->read4p = 0;
                pexit("hangup", 1);
        }
        for(;;){
                bp = devtab[er->mchan4->type]->bread(er->mchan4, ifc->maxtu, 0);
                if(!canrlock(ifc)){
                        freeb(bp);
                        continue;
                }
                if(waserror()){
                        runlock(ifc);
                        nexterror();
                }
                ifc->in++;
                bp->rp += ifc->m->hsize;
                if(ifc->lifc == nil)
                        freeb(bp);
                else
                        ipiput4(er->f, ifc, bp);
                runlock(ifc);
                poperror();
        }
}


/*
 *  process to read from the ethernet, IPv6
 */
static void
etherread6(void *a)
{
        Ipifc *ifc;
        Block *bp;
        Etherrock *er;

        ifc = a;
        er = ifc->arg;
        er->read6p = up;        /* hide identity under a rock for unbind */
        if(waserror()){
                er->read6p = 0;
                pexit("hangup", 1);
        }
        for(;;){
                bp = devtab[er->mchan6->type]->bread(er->mchan6, ifc->maxtu, 0);
                if(!canrlock(ifc)){
                        freeb(bp);
                        continue;
                }
                if(waserror()){
                        runlock(ifc);
                        nexterror();
                }
                ifc->in++;
                bp->rp += ifc->m->hsize;
                if(ifc->lifc == nil)
                        freeb(bp);
                else
                        ipiput6(er->f, ifc, bp);
                runlock(ifc);
                poperror();
        }
}

static void
etheraddmulti(Ipifc *ifc, uchar *a, uchar *)
{
        uchar mac[6];
        char buf[64];
        Etherrock *er = ifc->arg;
        int version;

        version = multicastea(mac, a);
        snprint(buf, sizeof buf, "addmulti %E", mac);
        switch(version){
        case V4:
                devtab[er->cchan4->type]->write(er->cchan4, buf, strlen(buf), 0);
                break;
        case V6:
                devtab[er->cchan6->type]->write(er->cchan6, buf, strlen(buf), 0);
                break;
        default:
                panic("etheraddmulti: version %d", version);
        }
}

static void
etherremmulti(Ipifc *ifc, uchar *a, uchar *)
{
        uchar mac[6];
        char buf[64];
        Etherrock *er = ifc->arg;
        int version;

        version = multicastea(mac, a);
        snprint(buf, sizeof buf, "remmulti %E", mac);
        switch(version){
        case V4:
                devtab[er->cchan4->type]->write(er->cchan4, buf, strlen(buf), 0);
                break;
        case V6:
                devtab[er->cchan6->type]->write(er->cchan6, buf, strlen(buf), 0);
                break;
        default:
                panic("etherremmulti: version %d", version);
        }
}

/*
 *  send an ethernet arp
 *  (only v4, v6 uses the neighbor discovery, rfc1970)
 */
static void
sendarp(Ipifc *ifc, Arpent *a)
{
        int n;
        Block *bp;
        Etherarp *e;
        Etherrock *er = ifc->arg;

        /* don't do anything if it's been less than a second since the last */
        if(NOW - a->ctime < 1000){
                arprelease(er->f->arp, a);
                return;
        }

        /* remove all but the last message */
        while((bp = a->hold) != nil){
                if(bp == a->last)
                        break;
                a->hold = bp->list;
                freeblist(bp);
        }

        /* try to keep it around for a second more */
        a->ctime = NOW;
        arprelease(er->f->arp, a);

        n = sizeof(Etherarp);
        if(n < a->type->mintu)
                n = a->type->mintu;
        bp = allocb(n);
        memset(bp->rp, 0, n);
        e = (Etherarp*)bp->rp;
        memmove(e->tpa, a->ip+IPv4off, sizeof(e->tpa));
        ipv4local(ifc, e->spa);
        memmove(e->sha, ifc->mac, sizeof(e->sha));
        memset(e->d, 0xff, sizeof(e->d));               /* ethernet broadcast */
        memmove(e->s, ifc->mac, sizeof(e->s));

        hnputs(e->type, ETARP);
        hnputs(e->hrd, 1);
        hnputs(e->pro, ETIP4);
        e->hln = sizeof(e->sha);
        e->pln = sizeof(e->spa);
        hnputs(e->op, ARPREQUEST);
        bp->wp += n;

        devtab[er->achan->type]->bwrite(er->achan, bp, 0);
}

static void
resolveaddr6(Ipifc *ifc, Arpent *a)
{
        int sflag;
        Block *bp;
        Etherrock *er = ifc->arg;
        uchar ipsrc[IPaddrlen];

        /* don't do anything if it's been less than a second since the last */
        if(NOW - a->ctime < ReTransTimer){
                arprelease(er->f->arp, a);
                return;
        }

        /* remove all but the last message */
        while((bp = a->hold) != nil){
                if(bp == a->last)
                        break;
                a->hold = bp->list;
                freeblist(bp);
        }

        /* try to keep it around for a second more */
        a->ctime = NOW;
        a->rtime = NOW + ReTransTimer;
        if(a->rxtsrem <= 0) {
                arprelease(er->f->arp, a);
                return;
        }

        a->rxtsrem--;
        arprelease(er->f->arp, a);

        if(sflag = ipv6anylocal(ifc, ipsrc))
                icmpns(er->f, ipsrc, sflag, a->ip, TARG_MULTI, ifc->mac);
}

/*
 *  send a gratuitous arp to refresh arp caches
 */
static void
sendgarp(Ipifc *ifc, uchar *ip)
{
        int n;
        Block *bp;
        Etherarp *e;
        Etherrock *er = ifc->arg;

        /* don't arp for our initial non address */
        if(ipcmp(ip, IPnoaddr) == 0)
                return;

        n = sizeof(Etherarp);
        if(n < ifc->m->mintu)
                n = ifc->m->mintu;
        bp = allocb(n);
        memset(bp->rp, 0, n);
        e = (Etherarp*)bp->rp;
        memmove(e->tpa, ip+IPv4off, sizeof(e->tpa));
        memmove(e->spa, ip+IPv4off, sizeof(e->spa));
        memmove(e->sha, ifc->mac, sizeof(e->sha));
        memset(e->d, 0xff, sizeof(e->d));               /* ethernet broadcast */
        memmove(e->s, ifc->mac, sizeof(e->s));

        hnputs(e->type, ETARP);
        hnputs(e->hrd, 1);
        hnputs(e->pro, ETIP4);
        e->hln = sizeof(e->sha);
        e->pln = sizeof(e->spa);
        hnputs(e->op, ARPREQUEST);
        bp->wp += n;

        devtab[er->achan->type]->bwrite(er->achan, bp, 0);
}

static void
recvarp(Ipifc *ifc)
{
        int n;
        Block *ebp, *rbp;
        Etherarp *e, *r;
        uchar ip[IPaddrlen];
        static uchar eprinted[4];
        Etherrock *er = ifc->arg;

        ebp = devtab[er->achan->type]->bread(er->achan, ifc->maxtu, 0);
        if(ebp == nil)
                return;

        e = (Etherarp*)ebp->rp;
        switch(nhgets(e->op)) {
        default:
                break;

        case ARPREPLY:
                /* check for machine using my ip address */
                v4tov6(ip, e->spa);
                if(iplocalonifc(ifc, ip) || ipproxyifc(er->f, ifc, ip)){
                        if(memcmp(e->sha, ifc->mac, sizeof(e->sha)) != 0){
                                print("arprep: 0x%E/0x%E also has ip addr %V\n",
                                        e->s, e->sha, e->spa);
                                break;
                        }
                }

                /* make sure we're not entering broadcast addresses */
                if(ipcmp(ip, ipbroadcast) == 0 ||
                        !memcmp(e->sha, etherbroadcast, sizeof(e->sha))){
                        print("arprep: 0x%E/0x%E cannot register broadcast address %I\n",
                                e->s, e->sha, e->spa);
                        break;
                }

                arpenter(er->f, V4, e->spa, e->sha, sizeof(e->sha), 0);
                break;

        case ARPREQUEST:
                /* don't answer arps till we know who we are */
                if(ifc->lifc == 0)
                        break;

                /* check for machine using my ip or ether address */
                v4tov6(ip, e->spa);
                if(iplocalonifc(ifc, ip) || ipproxyifc(er->f, ifc, ip)){
                        if(memcmp(e->sha, ifc->mac, sizeof(e->sha)) != 0){
                                if (memcmp(eprinted, e->spa, sizeof(e->spa))){
                                        /* print only once */
                                        print("arpreq: 0x%E also has ip addr %V\n", e->sha, e->spa);
                                        memmove(eprinted, e->spa, sizeof(e->spa));
                                }
                        }
                } else {
                        if(memcmp(e->sha, ifc->mac, sizeof(e->sha)) == 0){
                                print("arpreq: %V also has ether addr %E\n", e->spa, e->sha);
                                break;
                        }
                }

                /* refresh what we know about sender */
                arpenter(er->f, V4, e->spa, e->sha, sizeof(e->sha), 1);

                /* answer only requests for our address or systems we're proxying for */
                v4tov6(ip, e->tpa);
                if(!iplocalonifc(ifc, ip))
                if(!ipproxyifc(er->f, ifc, ip))
                        break;

                n = sizeof(Etherarp);
                if(n < ifc->mintu)
                        n = ifc->mintu;
                rbp = allocb(n);
                r = (Etherarp*)rbp->rp;
                memset(r, 0, sizeof(Etherarp));
                hnputs(r->type, ETARP);
                hnputs(r->hrd, 1);
                hnputs(r->pro, ETIP4);
                r->hln = sizeof(r->sha);
                r->pln = sizeof(r->spa);
                hnputs(r->op, ARPREPLY);
                memmove(r->tha, e->sha, sizeof(r->tha));
                memmove(r->tpa, e->spa, sizeof(r->tpa));
                memmove(r->sha, ifc->mac, sizeof(r->sha));
                memmove(r->spa, e->tpa, sizeof(r->spa));
                memmove(r->d, e->sha, sizeof(r->d));
                memmove(r->s, ifc->mac, sizeof(r->s));
                rbp->wp += n;

                devtab[er->achan->type]->bwrite(er->achan, rbp, 0);
        }
        freeb(ebp);
}

static void
recvarpproc(void *v)
{
        Ipifc *ifc = v;
        Etherrock *er = ifc->arg;

        er->arpp = up;
        if(waserror()){
                er->arpp = 0;
                pexit("hangup", 1);
        }
        for(;;)
                recvarp(ifc);
}

static int
multicastea(uchar *ea, uchar *ip)
{
        int x;

        switch(x = ipismulticast(ip)){
        case V4:
                ea[0] = 0x01;
                ea[1] = 0x00;
                ea[2] = 0x5e;
                ea[3] = ip[13] & 0x7f;
                ea[4] = ip[14];
                ea[5] = ip[15];
                break;
        case V6:
                ea[0] = 0x33;
                ea[1] = 0x33;
                ea[2] = ip[12];
                ea[3] = ip[13];
                ea[4] = ip[14];
                ea[5] = ip[15];
                break;
        }
        return x;
}

/*
 *  fill in an arp entry for broadcast or multicast
 *  addresses.  Return the first queued packet for the
 *  IP address.
 */
static Block*
multicastarp(Fs *f, Arpent *a, Medium *medium, uchar *mac)
{
        /* is it broadcast? */
        switch(ipforme(f, a->ip)){
        case Runi:
                return nil;
        case Rbcast:
                memset(mac, 0xff, 6);
                return arpresolve(f->arp, a, medium, mac);
        default:
                break;
        }

        /* if multicast, fill in mac */
        switch(multicastea(mac, a->ip)){
        case V4:
        case V6:
                return arpresolve(f->arp, a, medium, mac);
        }

        /* let arp take care of it */
        return nil;
}

void
ethermediumlink(void)
{
        addipmedium(&ethermedium);
        addipmedium(&gbemedium);
}


static void
etherpref2addr(uchar *pref, uchar *ea)
{
        pref[8] = ea[0] | 0x2;
        pref[9] = ea[1];
        pref[10] = ea[2];
        pref[11] = 0xFF;
        pref[12] = 0xFE;
        pref[13] = ea[3];
        pref[14] = ea[4];
        pref[15] = ea[5];
}