Source to net/if_ethersubr.c
/*
* Copyright (c) 1982, 1989 Regents of the University of California.
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 THE REGENTS 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.
*
* @(#)if_ethersubr.c 7.13 (Berkeley) 4/20/91
*/
#include "param.h"
#include "systm.h"
#include "kernel.h"
#include "malloc.h"
#include "mbuf.h"
#include "protosw.h"
#include "socket.h"
#include "ioctl.h"
#include "errno.h"
#include "syslog.h"
#include "if.h"
#include "netisr.h"
#include "route.h"
#include "if_llc.h"
#include "if_dl.h"
#include "machine/mtpr.h"
#ifdef INET
#include "../netinet/in.h"
#include "../netinet/in_var.h"
#endif
#include "../netinet/if_ether.h"
#ifdef NS
#include "../netns/ns.h"
#include "../netns/ns_if.h"
#endif
#ifdef ISO
#include "../netiso/argo_debug.h"
#include "../netiso/iso.h"
#include "../netiso/iso_var.h"
#include "../netiso/iso_snpac.h"
#endif
u_char etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
extern struct ifnet loif;
/*
* Ethernet output routine.
* Encapsulate a packet of type family for the local net.
* Use trailer local net encapsulation if enough data in first
* packet leaves a multiple of 512 bytes of data in remainder.
* Assumes that ifp is actually pointer to arpcom structure.
*/
ether_output(ifp, m0, dst, rt)
register struct ifnet *ifp;
struct mbuf *m0;
struct sockaddr *dst;
struct rtentry *rt;
{
short type;
int s, error = 0;
u_char edst[6];
struct in_addr idst;
register struct mbuf *m = m0;
struct mbuf *mcopy = (struct mbuf *)0;
register struct ether_header *eh;
int usetrailers, off, len = m->m_pkthdr.len;
#define ac ((struct arpcom *)ifp)
if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
error = ENETDOWN;
goto bad;
}
ifp->if_lastchange = time;
switch (dst->sa_family) {
#ifdef INET
case AF_INET:
idst = ((struct sockaddr_in *)dst)->sin_addr;
if (!arpresolve(ac, m, &idst, edst, &usetrailers))
return (0); /* if not yet resolved */
if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
mcopy = m_copy(m, 0, (int)M_COPYALL);
off = m->m_pkthdr.len - m->m_len;
if (usetrailers && off > 0 && (off & 0x1ff) == 0 &&
(m->m_flags & M_EXT) == 0 &&
m->m_data >= m->m_pktdat + 2 * sizeof (u_short)) {
type = ETHERTYPE_TRAIL + (off>>9);
m->m_data -= 2 * sizeof (u_short);
m->m_len += 2 * sizeof (u_short);
len += 2 * sizeof (u_short);
*mtod(m, u_short *) = htons((u_short)ETHERTYPE_IP);
*(mtod(m, u_short *) + 1) = htons((u_short)m->m_len);
goto gottrailertype;
}
type = ETHERTYPE_IP;
goto gottype;
#endif
#ifdef NS
case AF_NS:
type = ETHERTYPE_NS;
bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
(caddr_t)edst, sizeof (edst));
if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst)))
return (looutput(ifp, m, dst, rt));
if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1))
mcopy = m_copy(m, 0, (int)M_COPYALL);
goto gottype;
#endif
#ifdef ISO
case AF_ISO: {
int snpalen;
struct llc *l;
iso_again:
if (rt && rt->rt_gateway && (rt->rt_flags & RTF_UP)) {
if (rt->rt_flags & RTF_GATEWAY) {
if (rt->rt_llinfo) {
rt = (struct rtentry *)rt->rt_llinfo;
goto iso_again;
}
} else {
register struct sockaddr_dl *sdl =
(struct sockaddr_dl *)rt->rt_gateway;
if (sdl && sdl->sdl_family == AF_LINK
&& sdl->sdl_alen > 0) {
bcopy(LLADDR(sdl), (char *)edst,
sizeof(edst));
goto iso_resolved;
}
}
}
if ((error = iso_snparesolve(ifp, (struct sockaddr_iso *)dst,
(char *)edst, &snpalen)) > 0)
goto bad; /* Not Resolved */
iso_resolved:
if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1) &&
(mcopy = m_copy(m, 0, (int)M_COPYALL))) {
M_PREPEND(mcopy, sizeof (*eh), M_DONTWAIT);
if (mcopy) {
eh = mtod(mcopy, struct ether_header *);
bcopy((caddr_t)edst,
(caddr_t)eh->ether_dhost, sizeof (edst));
bcopy((caddr_t)ac->ac_enaddr,
(caddr_t)eh->ether_shost, sizeof (edst));
}
}
M_PREPEND(m, 3, M_DONTWAIT);
if (m == NULL)
return (0);
type = m->m_pkthdr.len;
l = mtod(m, struct llc *);
l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP;
l->llc_control = LLC_UI;
len += 3;
IFDEBUG(D_ETHER)
int i;
printf("unoutput: sending pkt to: ");
for (i=0; i<6; i++)
printf("%x ", edst[i] & 0xff);
printf("\n");
ENDDEBUG
} goto gottype;
#endif ISO
#ifdef RMP
case AF_RMP:
/*
* This is IEEE 802.3 -- the Ethernet `type' field is
* really a `length' field.
*/
type = m->m_len;
bcopy((caddr_t)dst->sa_data, (caddr_t)edst, sizeof(edst));
break;
#endif
case AF_UNSPEC:
eh = (struct ether_header *)dst->sa_data;
bcopy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst));
type = eh->ether_type;
goto gottype;
default:
printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
dst->sa_family);
error = EAFNOSUPPORT;
goto bad;
}
gottrailertype:
/*
* Packet to be sent as trailer: move first packet
* (control information) to end of chain.
*/
while (m->m_next)
m = m->m_next;
m->m_next = m0;
m = m0->m_next;
m0->m_next = 0;
gottype:
if (mcopy)
(void) looutput(ifp, mcopy, dst, rt);
/*
* Add local net header. If no space in first mbuf,
* allocate another.
*/
M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
if (m == 0) {
error = ENOBUFS;
goto bad;
}
eh = mtod(m, struct ether_header *);
type = htons((u_short)type);
bcopy((caddr_t)&type,(caddr_t)&eh->ether_type,
sizeof(eh->ether_type));
bcopy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst));
bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost,
sizeof(eh->ether_shost));
s = splimp();
/*
* Queue message on interface, and start output if interface
* not yet active.
*/
if (IF_QFULL(&ifp->if_snd)) {
IF_DROP(&ifp->if_snd);
splx(s);
error = ENOBUFS;
goto bad;
}
IF_ENQUEUE(&ifp->if_snd, m);
if ((ifp->if_flags & IFF_OACTIVE) == 0)
(*ifp->if_start)(ifp);
splx(s);
ifp->if_obytes += len + sizeof (struct ether_header);
if (edst[0] & 1)
ifp->if_omcasts++;
return (error);
bad:
if (m)
m_freem(m);
return (error);
}
/*
* Process a received Ethernet packet;
* the packet is in the mbuf chain m without
* the ether header, which is provided separately.
*/
ether_input(ifp, eh, m)
struct ifnet *ifp;
register struct ether_header *eh;
struct mbuf *m;
{
register struct ifqueue *inq;
register struct llc *l;
int s;
ifp->if_lastchange = time;
ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
sizeof(etherbroadcastaddr)) == 0)
m->m_flags |= M_BCAST;
else if (eh->ether_dhost[0] & 1)
m->m_flags |= M_MCAST;
if (m->m_flags & (M_BCAST|M_MCAST))
ifp->if_imcasts++;
switch (eh->ether_type) {
#ifdef INET
case ETHERTYPE_IP:
schednetisr(NETISR_IP);
inq = &ipintrq;
break;
case ETHERTYPE_ARP:
arpinput((struct arpcom *)ifp, m);
return;
#endif
#ifdef NS
case ETHERTYPE_NS:
schednetisr(NETISR_NS);
inq = &nsintrq;
break;
#endif
default:
#ifdef ISO
if (eh->ether_type > ETHERMTU)
goto dropanyway;
l = mtod(m, struct llc *);
switch (l->llc_control) {
case LLC_UI:
/* LLC_UI_P forbidden in class 1 service */
if ((l->llc_dsap == LLC_ISO_LSAP) &&
(l->llc_ssap == LLC_ISO_LSAP)) {
/* LSAP for ISO */
if (m->m_pkthdr.len > eh->ether_type)
m_adj(m, eh->ether_type - m->m_pkthdr.len);
m->m_data += 3; /* XXX */
m->m_len -= 3; /* XXX */
m->m_pkthdr.len -= 3; /* XXX */
M_PREPEND(m, sizeof *eh, M_DONTWAIT);
if (m == 0)
return;
*mtod(m, struct ether_header *) = *eh;
IFDEBUG(D_ETHER)
printf("clnp packet");
ENDDEBUG
schednetisr(NETISR_ISO);
inq = &clnlintrq;
break;
}
goto dropanyway;
case LLC_XID:
case LLC_XID_P:
if(m->m_len < 6)
goto dropanyway;
l->llc_window = 0;
l->llc_fid = 9;
l->llc_class = 1;
l->llc_dsap = l->llc_ssap = 0;
/* Fall through to */
case LLC_TEST:
case LLC_TEST_P:
{
struct sockaddr sa;
register struct ether_header *eh2;
int i;
u_char c = l->llc_dsap;
l->llc_dsap = l->llc_ssap;
l->llc_ssap = c;
if (m->m_flags & (M_BCAST | M_MCAST))
bcopy((caddr_t)ac->ac_enaddr,
(caddr_t)eh->ether_dhost, 6);
sa.sa_family = AF_UNSPEC;
sa.sa_len = sizeof(sa);
eh2 = (struct ether_header *)sa.sa_data;
for (i = 0; i < 6; i++) {
eh2->ether_shost[i] = c = eh->ether_dhost[i];
eh2->ether_dhost[i] =
eh->ether_dhost[i] = eh->ether_shost[i];
eh->ether_shost[i] = c;
}
ifp->if_output(ifp, m, &sa);
return;
}
dropanyway:
default:
m_freem(m);
return;
}
#else
m_freem(m);
return;
#endif ISO
}
s = splimp();
if (IF_QFULL(inq)) {
IF_DROP(inq);
m_freem(m);
} else
IF_ENQUEUE(inq, m);
splx(s);
}
/*
* Convert Ethernet address to printable (loggable) representation.
*/
static char digits[] = "0123456789abcdef";
char *
ether_sprintf(ap)
register u_char *ap;
{
register i;
static char etherbuf[18];
register char *cp = etherbuf;
for (i = 0; i < 6; i++) {
*cp++ = digits[*ap >> 4];
*cp++ = digits[*ap++ & 0xf];
*cp++ = ':';
}
*--cp = 0;
return (etherbuf);
}