freebsd-dev/sys/netatalk/ddp_output.c
Bosko Milekic 2a0c503e7a * Rename M_WAIT mbuf subsystem flag to M_TRYWAIT.
This is because calls with M_WAIT (now M_TRYWAIT) may not wait
  forever when nothing is available for allocation, and may end up
  returning NULL. Hopefully we now communicate more of the right thing
  to developers and make it very clear that it's necessary to check whether
  calls with M_(TRY)WAIT also resulted in a failed allocation.
  M_TRYWAIT basically means "try harder, block if necessary, but don't
  necessarily wait forever." The time spent blocking is tunable with
  the kern.ipc.mbuf_wait sysctl.
  M_WAIT is now deprecated but still defined for the next little while.

* Fix a typo in a comment in mbuf.h

* Fix some code that was actually passing the mbuf subsystem's M_WAIT to
  malloc(). Made it pass M_WAITOK instead. If we were ever to redefine the
  value of the M_WAIT flag, this could have became a big problem.
2000-12-21 21:44:31 +00:00

231 lines
6.1 KiB
C

/*
* 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
*/
/* $FreeBSD$ */
#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
#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_TRYWAIT );
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 );
#ifdef NETATALK_DEBUG
printf ("ddp_output: from %d.%d:%d to %d.%d:%d\n",
ntohs(deh->deh_snet), deh->deh_snode, deh->deh_sport,
ntohs(deh->deh_dnet), deh->deh_dnode, deh->deh_dport);
#endif
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 );
#ifdef NETATALK_DEBUG
if (ro->ro_rt == NULL)
printf ("ddp_route: no ro_rt.\n");
else if (ro->ro_rt->rt_ifa == NULL)
printf ("ddp_route: no ro_rt->rt_ifa\n");
else
printf ("ddp_route: no ro_rt->rt_ifa->ifa_ifp\n");
#endif
return( ENETUNREACH );
}
if ( aa == NULL ) {
#ifdef NETATALK_DEBUG
printf( "ddp_route: no atalk address found for %s%d\n",
ifp->if_name, ifp->if_unit);
#endif
m_freem( m );
return( ENETUNREACH );
}
/*
* 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_TRYWAIT, 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++;
#ifdef NETATALK_DEBUG
printf ("ddp_route: from %d.%d to %d.%d, via %d.%d (%s%d)\n",
ntohs(satosat(&aa->aa_addr)->sat_addr.s_net),
satosat(&aa->aa_addr)->sat_addr.s_node,
ntohs(satosat(&ro->ro_dst)->sat_addr.s_net),
satosat(&ro->ro_dst)->sat_addr.s_node,
ntohs(gate.sat_addr.s_net),
gate.sat_addr.s_node,
ifp->if_name, ifp->if_unit);
#endif
/* short-circuit the output if we're sending this to ourself */
if ((satosat(&aa->aa_addr)->sat_addr.s_net == satosat(&ro->ro_dst)->sat_addr.s_net) &&
(satosat(&aa->aa_addr)->sat_addr.s_node == satosat(&ro->ro_dst)->sat_addr.s_node))
{
return (if_simloop(ifp, m, gate.sat_family, 0));
}
return((*ifp->if_output)( ifp,
m, (struct sockaddr *)&gate, NULL)); /* XXX */
}