freebsd-dev/sys/netatalk/aarp.c
Julian Elischer bf7c9470c1 Slight cleanup of aarp code
Submitted by: Ian Dowse <iedowse@maths.tcd.ie>
PR: kern/17583

This PR is still open as Ther is still ongoing investigation.
2000-03-29 17:12:09 +00:00

619 lines
16 KiB
C

/*
* Copyright (c) 1990,1991 Regents of The University of Michigan.
* All Rights Reserved.
*
* $FreeBSD$
*/
#include "opt_atalk.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <netinet/in.h>
#undef s_net
#include <netinet/if_ether.h>
#include <netatalk/at.h>
#include <netatalk/at_var.h>
#include <netatalk/aarp.h>
#include <netatalk/phase2.h>
#include <netatalk/at_extern.h>
static void aarptfree( struct aarptab *aat);
static void at_aarpinput( struct arpcom *ac, struct mbuf *m);
#define AARPTAB_BSIZ 9
#define AARPTAB_NB 19
#define AARPTAB_SIZE (AARPTAB_BSIZ * AARPTAB_NB)
static struct aarptab aarptab[AARPTAB_SIZE];
#define AARPTAB_HASH(a) \
((((a).s_net << 8 ) + (a).s_node ) % AARPTAB_NB )
#define AARPTAB_LOOK(aat,addr) { \
int n; \
aat = &aarptab[ AARPTAB_HASH(addr) * AARPTAB_BSIZ ]; \
for ( n = 0; n < AARPTAB_BSIZ; n++, aat++ ) \
if ( aat->aat_ataddr.s_net == (addr).s_net && \
aat->aat_ataddr.s_node == (addr).s_node ) \
break; \
if ( n >= AARPTAB_BSIZ ) \
aat = 0; \
}
#define AARPT_AGE (60 * 1)
#define AARPT_KILLC 20
#define AARPT_KILLI 3
# if !defined( __FreeBSD__ )
extern u_char etherbroadcastaddr[6];
# endif __FreeBSD__
static u_char atmulticastaddr[ 6 ] = {
0x09, 0x00, 0x07, 0xff, 0xff, 0xff,
};
u_char at_org_code[ 3 ] = {
0x08, 0x00, 0x07,
};
u_char aarp_org_code[ 3 ] = {
0x00, 0x00, 0x00,
};
static struct callout_handle aarptimer_ch =
CALLOUT_HANDLE_INITIALIZER(&aarptimer_ch);
static void
aarptimer(void *ignored)
{
struct aarptab *aat;
int i, s;
aarptimer_ch = timeout( aarptimer, (caddr_t)0, AARPT_AGE * hz );
aat = aarptab;
for ( i = 0; i < AARPTAB_SIZE; i++, aat++ ) {
if ( aat->aat_flags == 0 || ( aat->aat_flags & ATF_PERM ))
continue;
if ( ++aat->aat_timer < (( aat->aat_flags & ATF_COM ) ?
AARPT_KILLC : AARPT_KILLI ))
continue;
s = splimp();
aarptfree( aat );
splx( s );
}
}
/*
* search through the network addresses to find one that includes
* the given network.. remember to take netranges into
* consideration.
*/
struct at_ifaddr *
at_ifawithnet(struct sockaddr_at *sat )
{
struct at_ifaddr *aa;
struct sockaddr_at *sat2;
for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
sat2 = &(aa->aa_addr);
if ( sat2->sat_addr.s_net == sat->sat_addr.s_net ) {
break;
}
if( (aa->aa_flags & AFA_PHASE2 )
&& (ntohs(aa->aa_firstnet) <= ntohs(sat->sat_addr.s_net))
&& (ntohs(aa->aa_lastnet) >= ntohs(sat->sat_addr.s_net))) {
break;
}
}
return( aa );
}
static void
aarpwhohas( struct arpcom *ac, struct sockaddr_at *sat )
{
struct mbuf *m;
struct ether_header *eh;
struct ether_aarp *ea;
struct at_ifaddr *aa;
struct llc *llc;
struct sockaddr sa;
if (( m = m_gethdr( M_DONTWAIT, MT_DATA )) == NULL ) {
return;
}
m->m_len = sizeof( *ea );
m->m_pkthdr.len = sizeof( *ea );
MH_ALIGN( m, sizeof( *ea ));
ea = mtod( m, struct ether_aarp *);
bzero((caddr_t)ea, sizeof( *ea ));
ea->aarp_hrd = htons( AARPHRD_ETHER );
ea->aarp_pro = htons( ETHERTYPE_AT );
ea->aarp_hln = sizeof( ea->aarp_sha );
ea->aarp_pln = sizeof( ea->aarp_spu );
ea->aarp_op = htons( AARPOP_REQUEST );
bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->aarp_sha,
sizeof( ea->aarp_sha ));
/*
* We need to check whether the output ethernet type should
* be phase 1 or 2. We have the interface that we'll be sending
* the aarp out. We need to find an AppleTalk network on that
* interface with the same address as we're looking for. If the
* net is phase 2, generate an 802.2 and SNAP header.
*/
if ((aa = at_ifawithnet( sat )) == NULL) {
m_freem( m );
return;
}
eh = (struct ether_header *)sa.sa_data;
if ( aa->aa_flags & AFA_PHASE2 ) {
bcopy((caddr_t)atmulticastaddr, (caddr_t)eh->ether_dhost,
sizeof( eh->ether_dhost ));
eh->ether_type = htons(sizeof(struct llc) + sizeof(struct ether_aarp));
M_PREPEND( m, sizeof( struct llc ), M_WAIT );
llc = mtod( m, struct llc *);
llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
llc->llc_control = LLC_UI;
bcopy( aarp_org_code, llc->llc_org_code, sizeof( aarp_org_code ));
llc->llc_ether_type = htons( ETHERTYPE_AARP );
bcopy( &AA_SAT( aa )->sat_addr.s_net, ea->aarp_spnet,
sizeof( ea->aarp_spnet ));
bcopy( &sat->sat_addr.s_net, ea->aarp_tpnet,
sizeof( ea->aarp_tpnet ));
ea->aarp_spnode = AA_SAT( aa )->sat_addr.s_node;
ea->aarp_tpnode = sat->sat_addr.s_node;
} else {
bcopy((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
sizeof( eh->ether_dhost ));
eh->ether_type = htons( ETHERTYPE_AARP );
ea->aarp_spa = AA_SAT( aa )->sat_addr.s_node;
ea->aarp_tpa = sat->sat_addr.s_node;
}
#ifdef NETATALKDEBUG
printf("aarp: sending request for %u.%u\n",
ntohs(AA_SAT( aa )->sat_addr.s_net),
AA_SAT( aa )->sat_addr.s_node);
#endif /* NETATALKDEBUG */
sa.sa_len = sizeof( struct sockaddr );
sa.sa_family = AF_UNSPEC;
(*ac->ac_if.if_output)(&ac->ac_if,
m, &sa, NULL); /* XXX NULL should be routing information */
}
int
aarpresolve( ac, m, destsat, desten )
struct arpcom *ac;
struct mbuf *m;
struct sockaddr_at *destsat;
u_char *desten;
{
struct at_ifaddr *aa;
struct aarptab *aat;
int s;
if ( at_broadcast( destsat )) {
m->m_flags |= M_BCAST;
if ((aa = at_ifawithnet( destsat )) == NULL) {
m_freem( m );
return( 0 );
}
if ( aa->aa_flags & AFA_PHASE2 ) {
bcopy( (caddr_t)atmulticastaddr, (caddr_t)desten,
sizeof( atmulticastaddr ));
} else {
bcopy( (caddr_t)etherbroadcastaddr, (caddr_t)desten,
sizeof( etherbroadcastaddr ));
}
return( 1 );
}
s = splimp();
AARPTAB_LOOK( aat, destsat->sat_addr );
if ( aat == 0 ) { /* No entry */
aat = aarptnew( &destsat->sat_addr );
if ( aat == 0 ) {
panic( "aarpresolve: no free entry" );
}
aat->aat_hold = m;
aarpwhohas( ac, destsat );
splx( s );
return( 0 );
}
/* found an entry */
aat->aat_timer = 0;
if ( aat->aat_flags & ATF_COM ) { /* entry is COMplete */
bcopy( (caddr_t)aat->aat_enaddr, (caddr_t)desten,
sizeof( aat->aat_enaddr ));
splx( s );
return( 1 );
}
/* entry has not completed */
if ( aat->aat_hold ) {
m_freem( aat->aat_hold );
}
aat->aat_hold = m;
aarpwhohas( ac, destsat );
splx( s );
return( 0 );
}
void
aarpinput( ac, m )
struct arpcom *ac;
struct mbuf *m;
{
struct arphdr *ar;
if ( ac->ac_if.if_flags & IFF_NOARP )
goto out;
if ( m->m_len < sizeof( struct arphdr )) {
goto out;
}
ar = mtod( m, struct arphdr *);
if ( ntohs( ar->ar_hrd ) != AARPHRD_ETHER ) {
goto out;
}
if ( m->m_len < sizeof( struct arphdr ) + 2 * ar->ar_hln +
2 * ar->ar_pln ) {
goto out;
}
switch( ntohs( ar->ar_pro )) {
case ETHERTYPE_AT :
at_aarpinput( ac, m );
return;
default:
break;
}
out:
m_freem( m );
}
static void
at_aarpinput( struct arpcom *ac, struct mbuf *m)
{
struct ether_aarp *ea;
struct at_ifaddr *aa;
struct aarptab *aat;
struct ether_header *eh;
struct llc *llc;
struct sockaddr_at sat;
struct sockaddr sa;
struct at_addr spa, tpa, ma;
int op;
u_short net;
ea = mtod( m, struct ether_aarp *);
/* Check to see if from my hardware address */
if ( !bcmp(( caddr_t )ea->aarp_sha, ( caddr_t )ac->ac_enaddr,
sizeof( ac->ac_enaddr ))) {
m_freem( m );
return;
}
op = ntohs( ea->aarp_op );
bcopy( ea->aarp_tpnet, &net, sizeof( net ));
if ( net != 0 ) { /* should be ATADDR_ANYNET? */
sat.sat_len = sizeof(struct sockaddr_at);
sat.sat_family = AF_APPLETALK;
sat.sat_addr.s_net = net;
if ((aa = at_ifawithnet( &sat )) == NULL) {
m_freem( m );
return;
}
bcopy( ea->aarp_spnet, &spa.s_net, sizeof( spa.s_net ));
bcopy( ea->aarp_tpnet, &tpa.s_net, sizeof( tpa.s_net ));
} else {
/*
* Since we don't know the net, we just look for the first
* phase 1 address on the interface.
*/
for (aa = (struct at_ifaddr *)ac->ac_if.if_addrhead.tqh_first; aa;
aa = (struct at_ifaddr *)aa->aa_ifa.ifa_link.tqe_next) {
if ( AA_SAT( aa )->sat_family == AF_APPLETALK &&
( aa->aa_flags & AFA_PHASE2 ) == 0 ) {
break;
}
}
if ( aa == NULL ) {
m_freem( m );
return;
}
tpa.s_net = spa.s_net = AA_SAT( aa )->sat_addr.s_net;
}
spa.s_node = ea->aarp_spnode;
tpa.s_node = ea->aarp_tpnode;
ma.s_net = AA_SAT( aa )->sat_addr.s_net;
ma.s_node = AA_SAT( aa )->sat_addr.s_node;
/*
* This looks like it's from us.
*/
if ( spa.s_net == ma.s_net && spa.s_node == ma.s_node ) {
if ( aa->aa_flags & AFA_PROBING ) {
/*
* We're probing, someone either responded to our probe, or
* probed for the same address we'd like to use. Change the
* address we're probing for.
*/
untimeout( aarpprobe, ac, aa->aa_ch );
wakeup( aa );
m_freem( m );
return;
} else if ( op != AARPOP_PROBE ) {
/*
* This is not a probe, and we're not probing. This means
* that someone's saying they have the same source address
* as the one we're using. Get upset...
*/
log( LOG_ERR,
"aarp: duplicate AT address!! %x:%x:%x:%x:%x:%x\n",
ea->aarp_sha[ 0 ], ea->aarp_sha[ 1 ], ea->aarp_sha[ 2 ],
ea->aarp_sha[ 3 ], ea->aarp_sha[ 4 ], ea->aarp_sha[ 5 ]);
m_freem( m );
return;
}
}
AARPTAB_LOOK( aat, spa );
if ( aat ) {
if ( op == AARPOP_PROBE ) {
/*
* Someone's probing for spa, dealocate the one we've got,
* so that if the prober keeps the address, we'll be able
* to arp for him.
*/
aarptfree( aat );
m_freem( m );
return;
}
bcopy(( caddr_t )ea->aarp_sha, ( caddr_t )aat->aat_enaddr,
sizeof( ea->aarp_sha ));
aat->aat_flags |= ATF_COM;
if ( aat->aat_hold ) {
struct mbuf *mhold = aat->aat_hold;
aat->aat_hold = NULL;
sat.sat_len = sizeof(struct sockaddr_at);
sat.sat_family = AF_APPLETALK;
sat.sat_addr = spa;
(*ac->ac_if.if_output)( &ac->ac_if, mhold,
(struct sockaddr *)&sat, NULL); /* XXX */
}
} else if ((tpa.s_net == ma.s_net)
&& (tpa.s_node == ma.s_node)
&& (op != AARPOP_PROBE)
&& ((aat = aarptnew( &spa )) != NULL)) {
bcopy(( caddr_t )ea->aarp_sha, ( caddr_t )aat->aat_enaddr,
sizeof( ea->aarp_sha ));
aat->aat_flags |= ATF_COM;
}
/*
* Don't respond to responses, and never respond if we're
* still probing.
*/
if ( tpa.s_net != ma.s_net || tpa.s_node != ma.s_node ||
op == AARPOP_RESPONSE || ( aa->aa_flags & AFA_PROBING )) {
m_freem( m );
return;
}
bcopy(( caddr_t )ea->aarp_sha, ( caddr_t )ea->aarp_tha,
sizeof( ea->aarp_sha ));
bcopy(( caddr_t )ac->ac_enaddr, ( caddr_t )ea->aarp_sha,
sizeof( ea->aarp_sha ));
/* XXX */
eh = (struct ether_header *)sa.sa_data;
bcopy(( caddr_t )ea->aarp_tha, ( caddr_t )eh->ether_dhost,
sizeof( eh->ether_dhost ));
if ( aa->aa_flags & AFA_PHASE2 ) {
eh->ether_type = htons( sizeof( struct llc ) +
sizeof( struct ether_aarp ));
M_PREPEND( m, sizeof( struct llc ), M_DONTWAIT );
if ( m == NULL ) {
return;
}
llc = mtod( m, struct llc *);
llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
llc->llc_control = LLC_UI;
bcopy( aarp_org_code, llc->llc_org_code, sizeof( aarp_org_code ));
llc->llc_ether_type = htons( ETHERTYPE_AARP );
bcopy( ea->aarp_spnet, ea->aarp_tpnet, sizeof( ea->aarp_tpnet ));
bcopy( &ma.s_net, ea->aarp_spnet, sizeof( ea->aarp_spnet ));
} else {
eh->ether_type = htons( ETHERTYPE_AARP );
}
ea->aarp_tpnode = ea->aarp_spnode;
ea->aarp_spnode = ma.s_node;
ea->aarp_op = htons( AARPOP_RESPONSE );
sa.sa_len = sizeof( struct sockaddr );
sa.sa_family = AF_UNSPEC;
(*ac->ac_if.if_output)( &ac->ac_if, m, &sa, NULL); /* XXX */
return;
}
static void
aarptfree( struct aarptab *aat)
{
if ( aat->aat_hold )
m_freem( aat->aat_hold );
aat->aat_hold = NULL;
aat->aat_timer = aat->aat_flags = 0;
aat->aat_ataddr.s_net = 0;
aat->aat_ataddr.s_node = 0;
}
struct aarptab *
aarptnew( addr )
struct at_addr *addr;
{
int n;
int oldest = -1;
struct aarptab *aat, *aato = NULL;
static int first = 1;
if ( first ) {
first = 0;
aarptimer_ch = timeout( aarptimer, (caddr_t)0, hz );
}
aat = &aarptab[ AARPTAB_HASH( *addr ) * AARPTAB_BSIZ ];
for ( n = 0; n < AARPTAB_BSIZ; n++, aat++ ) {
if ( aat->aat_flags == 0 )
goto out;
if ( aat->aat_flags & ATF_PERM )
continue;
if ((int) aat->aat_timer > oldest ) {
oldest = aat->aat_timer;
aato = aat;
}
}
if ( aato == NULL )
return( NULL );
aat = aato;
aarptfree( aat );
out:
aat->aat_ataddr = *addr;
aat->aat_flags = ATF_INUSE;
return( aat );
}
void
aarpprobe( void *arg )
{
struct arpcom *ac = arg;
struct mbuf *m;
struct ether_header *eh;
struct ether_aarp *ea;
struct at_ifaddr *aa;
struct llc *llc;
struct sockaddr sa;
/*
* We need to check whether the output ethernet type should
* be phase 1 or 2. We have the interface that we'll be sending
* the aarp out. We need to find an AppleTalk network on that
* interface with the same address as we're looking for. If the
* net is phase 2, generate an 802.2 and SNAP header.
*/
for (aa = (struct at_ifaddr *)ac->ac_if.if_addrhead.tqh_first; aa;
aa = (struct at_ifaddr *)aa->aa_ifa.ifa_link.tqe_next) {
if ( AA_SAT( aa )->sat_family == AF_APPLETALK &&
( aa->aa_flags & AFA_PROBING )) {
break;
}
}
if ( aa == NULL ) { /* serious error XXX */
printf( "aarpprobe why did this happen?!\n" );
return;
}
if ( aa->aa_probcnt <= 0 ) {
aa->aa_flags &= ~AFA_PROBING;
wakeup( aa );
return;
} else {
aa->aa_ch = timeout( aarpprobe, (caddr_t)ac, hz / 5 );
}
if (( m = m_gethdr( M_DONTWAIT, MT_DATA )) == NULL ) {
return;
}
m->m_len = sizeof( *ea );
m->m_pkthdr.len = sizeof( *ea );
MH_ALIGN( m, sizeof( *ea ));
ea = mtod( m, struct ether_aarp *);
bzero((caddr_t)ea, sizeof( *ea ));
ea->aarp_hrd = htons( AARPHRD_ETHER );
ea->aarp_pro = htons( ETHERTYPE_AT );
ea->aarp_hln = sizeof( ea->aarp_sha );
ea->aarp_pln = sizeof( ea->aarp_spu );
ea->aarp_op = htons( AARPOP_PROBE );
bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->aarp_sha,
sizeof( ea->aarp_sha ));
eh = (struct ether_header *)sa.sa_data;
if ( aa->aa_flags & AFA_PHASE2 ) {
bcopy((caddr_t)atmulticastaddr, (caddr_t)eh->ether_dhost,
sizeof( eh->ether_dhost ));
eh->ether_type = htons( sizeof( struct llc ) +
sizeof( struct ether_aarp ));
M_PREPEND( m, sizeof( struct llc ), M_WAIT );
llc = mtod( m, struct llc *);
llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
llc->llc_control = LLC_UI;
bcopy( aarp_org_code, llc->llc_org_code, sizeof( aarp_org_code ));
llc->llc_ether_type = htons( ETHERTYPE_AARP );
bcopy( &AA_SAT( aa )->sat_addr.s_net, ea->aarp_spnet,
sizeof( ea->aarp_spnet ));
bcopy( &AA_SAT( aa )->sat_addr.s_net, ea->aarp_tpnet,
sizeof( ea->aarp_tpnet ));
ea->aarp_spnode = ea->aarp_tpnode = AA_SAT( aa )->sat_addr.s_node;
} else {
bcopy((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
sizeof( eh->ether_dhost ));
eh->ether_type = htons( ETHERTYPE_AARP );
ea->aarp_spa = ea->aarp_tpa = AA_SAT( aa )->sat_addr.s_node;
}
#ifdef NETATALKDEBUG
printf("aarp: sending probe for %u.%u\n",
ntohs(AA_SAT( aa )->sat_addr.s_net),
AA_SAT( aa )->sat_addr.s_node);
#endif /* NETATALKDEBUG */
sa.sa_len = sizeof( struct sockaddr );
sa.sa_family = AF_UNSPEC;
(*ac->ac_if.if_output)(&ac->ac_if, m, &sa, NULL); /* XXX */
aa->aa_probcnt--;
}
void
aarp_clean(void)
{
struct aarptab *aat;
int i;
untimeout( aarptimer, 0, aarptimer_ch );
for ( i = 0, aat = aarptab; i < AARPTAB_SIZE; i++, aat++ ) {
if ( aat->aat_hold ) {
m_freem( aat->aat_hold );
aat->aat_hold = NULL;
}
}
}