freebsd-dev/sys/netatalk/ddp_output.c

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/*
* Copyright (c) 1990,1991 Regents of The University of Michigan.
* All Rights Reserved.
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby granted,
* provided that the above copyright notice appears in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation, and that the name of The University
* of Michigan not be used in advertising or publicity pertaining to
* distribution of the software without specific, written prior
* permission. This software is supplied as is without expressed or
* implied warranties of any kind.
*
* Research Systems Unix Group
* The University of Michigan
* c/o Mike Clark
* 535 W. William Street
* Ann Arbor, Michigan
* +1-313-763-0525
* netatalk@itd.umich.edu
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <net/if.h>
#include <net/route.h>
#undef s_net
1996-09-10 08:32:01 +00:00
#include <netatalk/at.h>
#include <netatalk/at_var.h>
#include <netatalk/ddp.h>
#include <netatalk/ddp_var.h>
#include <netatalk/at_extern.h>
int ddp_cksum = 1;
int
ddp_output( struct mbuf *m, struct socket *so)
{
struct ddpehdr *deh;
struct ddpcb *ddp = sotoddpcb( so );
M_PREPEND( m, sizeof( struct ddpehdr ), M_WAIT );
deh = mtod( m, struct ddpehdr *);
deh->deh_pad = 0;
deh->deh_hops = 0;
deh->deh_len = m->m_pkthdr.len;
deh->deh_dnet = ddp->ddp_fsat.sat_addr.s_net;
deh->deh_dnode = ddp->ddp_fsat.sat_addr.s_node;
deh->deh_dport = ddp->ddp_fsat.sat_port;
deh->deh_snet = ddp->ddp_lsat.sat_addr.s_net;
deh->deh_snode = ddp->ddp_lsat.sat_addr.s_node;
deh->deh_sport = ddp->ddp_lsat.sat_port;
/*
* The checksum calculation is done after all of the other bytes have
* been filled in.
*/
if ( ddp_cksum ) {
deh->deh_sum = at_cksum( m, sizeof( int ));
} else {
deh->deh_sum = 0;
}
deh->deh_bytes = htonl( deh->deh_bytes );
return( ddp_route( m, &ddp->ddp_route ));
}
u_short
at_cksum( struct mbuf *m, int skip)
{
u_char *data, *end;
u_long cksum = 0;
for (; m; m = m->m_next ) {
for ( data = mtod( m, u_char * ), end = data + m->m_len; data < end;
data++ ) {
if ( skip ) {
skip--;
continue;
}
cksum = ( cksum + *data ) << 1;
if ( cksum & 0x00010000 ) {
cksum++;
}
cksum &= 0x0000ffff;
}
}
if ( cksum == 0 ) {
cksum = 0x0000ffff;
}
return( (u_short)cksum );
}
int
ddp_route( struct mbuf *m, struct route *ro)
{
struct sockaddr_at gate;
struct elaphdr *elh;
struct mbuf *m0;
struct at_ifaddr *aa = NULL;
struct ifnet *ifp = NULL;
u_short net;
#if 0
/* Check for net zero, node zero ("myself") */
if (satosat(&ro->ro_dst)->sat_addr.s_net == ATADDR_ANYNET
&& satosat(&ro->ro_dst)->sat_addr.s_node == ATADDR_ANYNODE) {
/* Find the loopback interface */
}
#endif
/*
* if we have a route, find the ifa that refers to this route.
* I.e The ifa used to get to the gateway.
*/
if ( (ro->ro_rt == NULL)
|| ( ro->ro_rt->rt_ifa == NULL )
|| ( (ifp = ro->ro_rt->rt_ifa->ifa_ifp) == NULL )) {
rtalloc(ro);
}
if ( (ro->ro_rt != NULL)
&& ( ro->ro_rt->rt_ifa )
&& ( ifp = ro->ro_rt->rt_ifa->ifa_ifp )) {
net = ntohs(satosat(ro->ro_rt->rt_gateway)->sat_addr.s_net);
for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
if (((net == 0) || (aa->aa_ifp == ifp)) &&
net >= ntohs( aa->aa_firstnet ) &&
net <= ntohs( aa->aa_lastnet )) {
break;
}
}
} else {
m_freem( m );
return( EINVAL );
}
if ( aa == NULL ) {
printf( "ddp_route: oops\n" );
m_freem( m );
return( EINVAL );
}
/*
* if the destination address is on a directly attached node use that,
* else use the official gateway.
*/
if ( ntohs( satosat( &ro->ro_dst )->sat_addr.s_net ) >=
ntohs( aa->aa_firstnet ) &&
ntohs( satosat( &ro->ro_dst )->sat_addr.s_net ) <=
ntohs( aa->aa_lastnet )) {
gate = *satosat( &ro->ro_dst );
} else {
gate = *satosat( ro->ro_rt->rt_gateway );
}
/*
* There are several places in the kernel where data is added to
* an mbuf without ensuring that the mbuf pointer is aligned.
* This is bad for transition routing, since phase 1 and phase 2
* packets end up poorly aligned due to the three byte elap header.
*/
if ( !(aa->aa_flags & AFA_PHASE2) ) {
MGET( m0, M_WAIT, MT_HEADER );
if ( m0 == 0 ) {
m_freem( m );
printf("ddp_route: no buffers\n");
return( ENOBUFS );
}
m0->m_next = m;
/* XXX perhaps we ought to align the header? */
m0->m_len = SZ_ELAPHDR;
m = m0;
elh = mtod( m, struct elaphdr *);
elh->el_snode = satosat( &aa->aa_addr )->sat_addr.s_node;
elh->el_type = ELAP_DDPEXTEND;
elh->el_dnode = gate.sat_addr.s_node;
}
ro->ro_rt->rt_use++;
return((*ifp->if_output)( ifp,
m, (struct sockaddr *)&gate, NULL)); /* XXX */
}