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freebsd/sys/netatalk/aarp.c
Robert Watson 8e9013b4c4 Lock down the netatalk AARP code, which is responsible for appletalk 
address discovery and caching (similar to inet ARP).  Use a single
global mutex, aarptab_mtx, to protect the table.  Remove spl/spx.

Tested by:	Bob Bishop <rb@gid.co.uk>
2004-04-09 01:40:12 +00:00

655 lines
16 KiB
C
Raw Blame History

/*
* Copyright (c) 1990,1991 Regents of The University of Michigan.
* All Rights Reserved.
*
* $FreeBSD$
*/
#include "opt_atalk.h"
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mac.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];
static struct mtx aarptab_mtx;
MTX_SYSINIT(aarptab_mtx, &aarptab_mtx, "aarptab_mtx", MTX_DEF);
#define AARPTAB_LOCK() mtx_lock(&aarptab_mtx)
#define AARPTAB_UNLOCK() mtx_unlock(&aarptab_mtx)
#define AARPTAB_LOCK_ASSERT() mtx_assert(&aarptab_mtx, MA_OWNED)
#define AARPTAB_UNLOCK_ASSERT() mtx_assert(&aarptab_mtx, MA_NOTOWNED)
#define AARPTAB_HASH(a) \
((((a).s_net << 8) + (a).s_node) % AARPTAB_NB)
#define AARPTAB_LOOK(aat, addr) { \
int n; \
AARPTAB_LOCK_ASSERT(); \
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 = NULL; \
}
#define AARPT_AGE (60 * 1)
#define AARPT_KILLC 20
#define AARPT_KILLI 3
# if !defined(__FreeBSD__)
extern u_char etherbroadcastaddr[6];
# endif /* __FreeBSD__ */
static const u_char atmulticastaddr[ 6 ] = {
0x09, 0x00, 0x07, 0xff, 0xff, 0xff,
};
/*
* Not used?
*/
u_char at_org_code[ 3 ] = {
0x08, 0x00, 0x07,
};
const 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;
aarptimer_ch = timeout(aarptimer, (caddr_t)0, AARPT_AGE * hz);
aat = aarptab;
AARPTAB_LOCK();
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;
aarptfree(aat);
}
AARPTAB_UNLOCK();
}
/*
* 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_list; aa != NULL; 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;
AARPTAB_UNLOCK_ASSERT();
if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) {
return;
}
#ifdef MAC
mac_create_mbuf_linklayer(&ac->ac_if, m);
#endif
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(atmulticastaddr, 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_TRYWAIT);
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(&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(ac->ac_if.if_broadcastaddr, (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;
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(atmulticastaddr, (caddr_t)desten, sizeof(atmulticastaddr));
} else {
bcopy(ac->ac_if.if_broadcastaddr, (caddr_t)desten,
sizeof(ac->ac_if.if_addrlen));
}
return (1);
}
AARPTAB_LOCK();
AARPTAB_LOOK(aat, destsat->sat_addr);
if (aat == NULL) { /* No entry */
aat = aarptnew(&destsat->sat_addr);
if (aat == NULL) {
panic("aarpresolve: no free entry");
}
aat->aat_hold = m;
AARPTAB_UNLOCK();
aarpwhohas(ac, destsat);
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));
AARPTAB_UNLOCK();
return (1);
}
/* entry has not completed */
if (aat->aat_hold) {
m_freem(aat->aat_hold);
}
aat->aat_hold = m;
AARPTAB_UNLOCK();
aarpwhohas(ac, destsat);
return (0);
}
void
aarpintr(m)
struct mbuf *m;
{
struct arphdr *ar;
struct arpcom *ac;
ac = (struct arpcom *)m->m_pkthdr.rcvif;
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;
GIANT_REQUIRED;
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 *)TAILQ_FIRST(&ac->ac_if.if_addrhead); 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_LOCK();
AARPTAB_LOOK(aat, spa);
if (aat != NULL) {
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);
AARPTAB_UNLOCK();
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;
AARPTAB_UNLOCK();
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
AARPTAB_UNLOCK();
} 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;
AARPTAB_UNLOCK();
} else
AARPTAB_UNLOCK();
/*
* 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)
{
AARPTAB_LOCK_ASSERT();
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;
AARPTAB_LOCK_ASSERT();
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 *)TAILQ_FIRST(&ac->ac_if.if_addrhead); 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;
}
#ifdef MAC
mac_create_mbuf_linklayer(&ac->ac_if, m);
#endif
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(atmulticastaddr, 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_TRYWAIT);
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(&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(ac->ac_if.if_broadcastaddr, (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);
AARPTAB_LOCK();
for (i = 0, aat = aarptab; i < AARPTAB_SIZE; i++, aat++) {
if (aat->aat_hold) {
m_freem(aat->aat_hold);
aat->aat_hold = NULL;
}
}
AARPTAB_UNLOCK();
}
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