ref: 267b0baa1b860c1672429abecf5ede3bacf84eb9
dir: /sys/src/9/ip/ethermedium.c/
#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 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, Routehint *rh); static void etheraddmulti(Ipifc *ifc, uchar *a, uchar *ia); static void etherremmulti(Ipifc *ifc, uchar *a, uchar *ia); static void etherareg(Fs *f, Ipifc *ifc, Iplifc *lifc, uchar *ip); static Block* multicastarp(Fs *f, Arpent *a, uchar *mac, Routehint *rh); static Block* newEARP(void); static void sendarpreq(Fs *f, Arpent *a); static int multicastea(uchar *ea, uchar *ip); static void recvarpproc(void*); static void etherpref2addr(uchar *pref, uchar *ea); Medium ethermedium = { .name= "ether", .hsize= ETHERHDRSIZE, .mintu= ETHERMINTU, .maxtu= ETHERHDRSIZE+1500, .maclen= 6, .bind= etherbind, .unbind= etherunbind, .bwrite= etherbwrite, .addmulti= etheraddmulti, .remmulti= etherremmulti, .areg= etherareg, .pref2addr= etherpref2addr, }; Medium gbemedium = { .name= "gbe", .hsize= ETHERHDRSIZE, .mintu= ETHERMINTU, .maxtu= ETHERHDRSIZE+9000, .maclen= 6, .bind= etherbind, .unbind= etherunbind, .bwrite= etherbwrite, .addmulti= etheraddmulti, .remmulti= etherremmulti, .areg= etherareg, .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 */ static void etherbind(Ipifc *ifc, int argc, char **argv) { char addr[Maxpath], dir[Maxpath]; Etherrock *er; Chan *c; int n; if(argc < 2) error(Ebadarg); /* * get mac address */ snprint(addr, sizeof(addr), "%s/addr", argv[2]); c = namec(addr, Aopen, OREAD, 0); if(waserror()){ cclose(c); nexterror(); } n = devtab[c->type]->read(c, addr, sizeof(addr)-1, 0); if(n < 0) error(Eio); addr[n] = 0; if(parsemac(ifc->mac, addr, sizeof(ifc->mac)) != 6) error("could not find mac address"); cclose(c); poperror(); er = smalloc(sizeof(*er)); er->read4p = er->read6p = er->arpp = (void*)-1; er->mchan4 = er->cchan4 = er->mchan6 = er->cchan6 = er->achan = nil; er->f = ifc->conv->p->f; if(waserror()){ if(er->mchan4 != nil) cclose(er->mchan4); if(er->cchan4 != nil) cclose(er->cchan4); if(er->mchan6 != nil) cclose(er->mchan6); if(er->cchan6 != nil) cclose(er->cchan6); if(er->achan != nil) cclose(er->achan); free(er); 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 */ er->mchan4 = chandial(addr, nil, dir, &er->cchan4); /* * make it non-blocking */ devtab[er->cchan4->type]->write(er->cchan4, nbmsg, strlen(nbmsg), 0); /* * 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 */ er->mchan6 = chandial(addr, nil, dir, &er->cchan6); /* * make it non-blocking */ devtab[er->cchan6->type]->write(er->cchan6, nbmsg, strlen(nbmsg), 0); /* * open arp conversation */ snprint(addr, sizeof(addr), "%s!0x806", argv[2]); /* ETARP */ er->achan = chandial(addr, nil, nil, nil); poperror(); ifc->arg = er; kproc("etherread4", etherread4, ifc); kproc("etherread6", etherread6, ifc); kproc("recvarpproc", recvarpproc, ifc); } static void etherunbind(Ipifc *ifc) { Etherrock *er = ifc->arg; while(waserror()) ; /* wait for readers to start */ while(er->arpp == (void*)-1 || er->read4p == (void*)-1 || er->read6p == (void*)-1) tsleep(&up->sleep, return0, 0, 300); if(er->read4p != nil) postnote(er->read4p, 1, "unbind", 0); if(er->read6p != nil) postnote(er->read6p, 1, "unbind", 0); if(er->arpp != nil) postnote(er->arpp, 1, "unbind", 0); poperror(); while(waserror()) ; /* wait for readers to die */ while(er->arpp != nil || er->read4p != nil || er->read6p != nil) tsleep(&up->sleep, return0, 0, 300); poperror(); if(er->mchan4 != nil) cclose(er->mchan4); if(er->cchan4 != nil) cclose(er->cchan4); if(er->mchan6 != nil) cclose(er->mchan6); if(er->cchan6 != nil) cclose(er->cchan6); if(er->achan != nil) cclose(er->achan); 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, Routehint *rh) { 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, rh); if(a != nil){ /* check for broadcast or multicast */ bp = multicastarp(er->f, a, mac, rh); if(bp == nil){ /* don't do anything if it's been less than a second since the last */ if(a->utime - a->ctime < RETRANS_TIMER){ arprelease(er->f->arp, a); /* unlocks arp */ return; } switch(version){ case V4: sendarpreq(er->f, a); /* unlocks arp */ break; case V6: ndpsendsol(er->f, a); /* unlocks arp */ break; default: panic("etherbwrite: version %d", version); } return; } } /* need to have single block */ assert(bp->list == nil); /* make it a single block with space for the ether header */ bp = padblock(bp, ETHERHDRSIZE); if(BLEN(bp) < ETHERMINTU) bp = adjustblock(bp, ETHERMINTU); 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()) for(;;){ bp = devtab[er->mchan4->type]->bread(er->mchan4, ifc->maxtu, 0); if(bp == nil) break; rlock(ifc); if(waserror()){ runlock(ifc); nexterror(); } ifc->in++; if(ifc->lifc == nil || BLEN(bp) <= ETHERHDRSIZE) freeb(bp); else { bp->rp += ETHERHDRSIZE; ipiput4(er->f, ifc, bp); } runlock(ifc); poperror(); } er->read4p = nil; pexit("hangup", 1); } /* * 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()) for(;;){ bp = devtab[er->mchan6->type]->bread(er->mchan6, ifc->maxtu, 0); if(bp == nil) break; rlock(ifc); if(waserror()){ runlock(ifc); nexterror(); } ifc->in++; if(ifc->lifc == nil || BLEN(bp) <= ETHERHDRSIZE) freeb(bp); else { bp->rp += ETHERHDRSIZE; ipiput6(er->f, ifc, bp); } runlock(ifc); poperror(); } er->read6p = nil; pexit("hangup", 1); } static void etheraddmulti(Ipifc *ifc, uchar *a, uchar *) { uchar mac[6]; char buf[64]; Etherrock *er = ifc->arg; int version; version = multicastea(mac, a); sprint(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); sprint(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); } } static Block* newEARP(void) { Block *bp; bp = allocb(ETHERMINTU); bp->wp += ETHERMINTU; memset(bp->rp, 0, ETHERMINTU); return bp; } /* * send an ethernet arp * (only v4, v6 uses the neighbor discovery, rfc1970) */ static void sendarpreq(Fs *f, Arpent *a) { Block *bp; Etherarp *e; Ipifc *ifc = a->ifc; Etherrock *er = ifc->arg; uchar targ[IPv4addrlen], src[IPv4addrlen]; memmove(targ, a->ip+IPv4off, IPv4addrlen); arpcontinue(f->arp, a); if(!ipv4local(ifc, src, 0, targ)) return; bp = newEARP(); e = (Etherarp*)bp->rp; memmove(e->tpa, targ, sizeof(e->tpa)); memmove(e->spa, src, 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); devtab[er->achan->type]->bwrite(er->achan, bp, 0); } /* * send a gratuitous arp to refresh arp caches */ static void sendgarp(Ipifc *ifc, uchar *ip) { Block *bp; Etherarp *e; Etherrock *er = ifc->arg; bp = newEARP(); 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); devtab[er->achan->type]->bwrite(er->achan, bp, 0); } static void recvarp(Ipifc *ifc) { int forme; 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; rlock(ifc); e = (Etherarp*)ebp->rp; switch(nhgets(e->op)) { default: break; case ARPREPLY: /* make sure not to enter multi/broadcat address */ if(e->sha[0] & 1) break; /* check for machine using my ip address */ v4tov6(ip, e->spa); if(iplocalonifc(ifc, ip) != nil || 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; } } /* refresh what we know about sender */ arpenter(er->f, V4, e->spa, e->sha, sizeof(e->sha), e->tpa, ifc, 1); break; case ARPREQUEST: /* don't reply to multi/broadcat addresses */ if(e->sha[0] & 1) break; /* don't answer arps till we know who we are */ if(ifc->lifc == nil) break; /* check for machine using my ip or ether address */ v4tov6(ip, e->spa); if(iplocalonifc(ifc, ip) != nil || ipproxyifc(er->f, ifc, ip)){ if(memcmp(e->sha, ifc->mac, sizeof(e->sha)) != 0){ if(memcmp(eprinted, e->spa, sizeof(e->spa)) != 0){ /* print only once */ print("arpreq: 0x%E also has ip addr %V\n", e->sha, e->spa); memmove(eprinted, e->spa, sizeof(e->spa)); } break; } } 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; } } /* * when request is for our address or systems we're proxying for, * enter senders address into arp table and reply, otherwise just * refresh the senders address. */ v4tov6(ip, e->tpa); forme = iplocalonifc(ifc, ip) != nil || ipproxyifc(er->f, ifc, ip); if(arpenter(er->f, V4, e->spa, e->sha, sizeof(e->sha), e->tpa, ifc, !forme) < 0 || !forme) break; rbp = newEARP(); r = (Etherarp*)rbp->rp; 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)); runlock(ifc); freeb(ebp); devtab[er->achan->type]->bwrite(er->achan, rbp, 0); return; } runlock(ifc); freeb(ebp); } static void recvarpproc(void *v) { Ipifc *ifc = v; Etherrock *er = ifc->arg; er->arpp = up; if(waserror()){ er->arpp = nil; 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, uchar *mac, Routehint *rh) { /* is it broadcast? */ if(ipforme(f, a->ip) == Rbcast){ memset(mac, 0xff, a->ifc->m->maclen); return arpresolve(f->arp, a, mac, rh); } /* if multicast, fill in mac */ switch(multicastea(mac, a->ip)){ case V4: case V6: return arpresolve(f->arp, a, mac, rh); } /* let arp take care of it */ return nil; } void ethermediumlink(void) { addipmedium(ðermedium); 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]; } static void etherareg(Fs *f, Ipifc *ifc, Iplifc *lifc, uchar *ip) { static char tdad[] = "dad6"; uchar a[IPaddrlen]; if(ipcmp(ip, IPnoaddr) == 0 || ipcmp(ip, v4prefix) == 0) return; if(isv4(ip)){ sendgarp(ifc, ip); return; } if((lifc->type&Rv4) != 0) return; if(!lifc->tentative){ icmpna6(f, lifc->local, v6allnodesL, ip, ifc->mac, 1<<5); return; } if(ipcmp(lifc->local, ip) != 0) return; /* temporarily add route for duplicate address detection */ ipv62smcast(a, ip); addroute(f, a, IPallbits, v6Unspecified, IPallbits, ip, Rmulti, ifc, tdad); if(waserror()){ remroute(f, a, IPallbits, v6Unspecified, IPallbits, ip, Rmulti, ifc, tdad); nexterror(); } icmpns6(f, 0, SRC_UNSPEC, ip, TARG_MULTI, ifc->mac); poperror(); remroute(f, a, IPallbits, v6Unspecified, IPallbits, ip, Rmulti, ifc, tdad); }