FreeBSD-5.3/sys/netatalk/ddp_output.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: src/sys/netatalk/ddp_output.c,v 1.24 2004/06/13 02:50:05 rwatson Exp $ */
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mac.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);
#ifdef MAC
SOCK_LOCK(so);
mac_create_mbuf_from_socket(so, m);
SOCK_UNLOCK(so);
#endif
M_PREPEND(m, sizeof(struct ddpehdr), M_TRYWAIT);
if (m == NULL)
return (ENOBUFS);
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_list; aa != NULL; 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\n",
ifp->if_xname);
#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 == NULL) {
m_freem(m);
printf("ddp_route: no buffers\n");
return (ENOBUFS);
}
#ifdef MAC
mac_create_mbuf_from_mbuf(m, m0);
#endif
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)\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_xname);
#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 */
}