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/*
* DECnet An implementation of the DECnet protocol suite for the LINUX
* operating system. DECnet is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* DECnet Routing Functions (Endnode and Router)
*
* Authors: Steve Whitehouse <SteveW@ACM.org>
* Eduardo Marcelo Serrat <emserrat@geocities.com>
*
* Changes:
* Steve Whitehouse : Fixes to allow "intra-ethernet" and
* "return-to-sender" bits on outgoing
* packets.
* Steve Whitehouse : Timeouts for cached routes.
* Steve Whitehouse : Use dst cache for input routes too.
* Steve Whitehouse : Fixed error values in dn_send_skb.
* Steve Whitehouse : Rework routing functions to better fit
* DECnet routing design
* Alexey Kuznetsov : New SMP locking
* Steve Whitehouse : More SMP locking changes & dn_cache_dump()
* Steve Whitehouse : Prerouting NF hook, now really is prerouting.
* Fixed possible skb leak in rtnetlink funcs.
* Steve Whitehouse : Dave Miller's dynamic hash table sizing and
* Alexey Kuznetsov's finer grained locking
* from ipv4/route.c.
* Steve Whitehouse : Routing is now starting to look like a
* sensible set of code now, mainly due to
* my copying the IPv4 routing code. The
* hooks here are modified and will continue
* to evolve for a while.
* Steve Whitehouse : Real SMP at last :-) Also new netfilter
* stuff. Look out raw sockets your days
* are numbered!
* Steve Whitehouse : Added return-to-sender functions. Added
* backlog congestion level return codes.
*
*/
/******************************************************************************
(c) 1995-1998 E.M. Serrat emserrat@geocities.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
*******************************************************************************/
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/inet.h>
#include <linux/route.h>
#include <net/sock.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/rtnetlink.h>
#include <linux/string.h>
#include <linux/netfilter_decnet.h>
#include <asm/errno.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/dn.h>
#include <net/dn_dev.h>
#include <net/dn_nsp.h>
#include <net/dn_route.h>
#include <net/dn_neigh.h>
#include <net/dn_fib.h>
struct dn_rt_hash_bucket
{
struct dn_route *chain;
rwlock_t lock;
} __attribute__((__aligned__(8)));
extern struct neigh_table dn_neigh_table;
static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
int dn_rt_min_delay = 2*HZ;
int dn_rt_max_delay = 10*HZ;
static unsigned long dn_rt_deadline = 0;
static int dn_dst_gc(void);
static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
static struct dst_entry *dn_dst_reroute(struct dst_entry *, struct sk_buff *skb);
static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
static void dn_dst_link_failure(struct sk_buff *);
static int dn_route_input(struct sk_buff *);
static void dn_run_flush(unsigned long dummy);
static struct dn_rt_hash_bucket *dn_rt_hash_table;
static unsigned dn_rt_hash_mask;
static struct timer_list dn_route_timer;
static struct timer_list dn_rt_flush_timer = { function: dn_run_flush };
int decnet_dst_gc_interval = 2;
static struct dst_ops dn_dst_ops = {
family: PF_DECnet,
protocol: __constant_htons(ETH_P_DNA_RT),
gc_thresh: 128,
gc: dn_dst_gc,
check: dn_dst_check,
reroute: dn_dst_reroute,
negative_advice: dn_dst_negative_advice,
link_failure: dn_dst_link_failure,
entry_size: sizeof(struct dn_route),
entries: ATOMIC_INIT(0),
};
static __inline__ unsigned dn_hash(unsigned short src, unsigned short dst)
{
unsigned short tmp = src ^ dst;
tmp ^= (tmp >> 3);
tmp ^= (tmp >> 5);
tmp ^= (tmp >> 10);
return dn_rt_hash_mask & (unsigned)tmp;
}
static void SMP_TIMER_NAME(dn_dst_check_expire)(unsigned long dummy)
{
int i;
struct dn_route *rt, **rtp;
unsigned long now = jiffies;
unsigned long expire = 120 * HZ;
for(i = 0; i <= dn_rt_hash_mask; i++) {
rtp = &dn_rt_hash_table[i].chain;
write_lock(&dn_rt_hash_table[i].lock);
while((rt=*rtp) != NULL) {
if (atomic_read(&rt->u.dst.__refcnt) ||
(now - rt->u.dst.lastuse) < expire) {
rtp = &rt->u.rt_next;
continue;
}
*rtp = rt->u.rt_next;
rt->u.rt_next = NULL;
dst_free(&rt->u.dst);
}
write_unlock(&dn_rt_hash_table[i].lock);
if ((jiffies - now) > 0)
break;
}
mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
}
SMP_TIMER_DEFINE(dn_dst_check_expire, dn_dst_task);
static int dn_dst_gc(void)
{
struct dn_route *rt, **rtp;
int i;
unsigned long now = jiffies;
unsigned long expire = 10 * HZ;
for(i = 0; i <= dn_rt_hash_mask; i++) {
write_lock_bh(&dn_rt_hash_table[i].lock);
rtp = &dn_rt_hash_table[i].chain;
while((rt=*rtp) != NULL) {
if (atomic_read(&rt->u.dst.__refcnt) ||
(now - rt->u.dst.lastuse) < expire) {
rtp = &rt->u.rt_next;
continue;
}
*rtp = rt->u.rt_next;
rt->u.rt_next = NULL;
dst_free(&rt->u.dst);
break;
}
write_unlock_bh(&dn_rt_hash_table[i].lock);
}
return 0;
}
static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
{
dst_release(dst);
return NULL;
}
static struct dst_entry *dn_dst_reroute(struct dst_entry *dst,
struct sk_buff *skb)
{
return NULL;
}
/*
* This is called through sendmsg() when you specify MSG_TRYHARD
* and there is already a route in cache.
*/
static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
{
dst_release(dst);
return NULL;
}
static void dn_dst_link_failure(struct sk_buff *skb)
{
return;
}
static void dn_insert_route(struct dn_route *rt, unsigned hash)
{
unsigned long now = jiffies;
write_lock_bh(&dn_rt_hash_table[hash].lock);
rt->u.rt_next = dn_rt_hash_table[hash].chain;
dn_rt_hash_table[hash].chain = rt;
dst_hold(&rt->u.dst);
rt->u.dst.__use++;
rt->u.dst.lastuse = now;
write_unlock_bh(&dn_rt_hash_table[hash].lock);
}
void SMP_TIMER_NAME(dn_run_flush)(unsigned long dummy)
{
int i;
struct dn_route *rt, *next;
for(i = 0; i < dn_rt_hash_mask; i++) {
write_lock_bh(&dn_rt_hash_table[i].lock);
if ((rt = xchg(&dn_rt_hash_table[i].chain, NULL)) == NULL)
goto nothing_to_declare;
for(; rt; rt=next) {
next = rt->u.rt_next;
rt->u.rt_next = NULL;
dst_free((struct dst_entry *)rt);
}
nothing_to_declare:
write_unlock_bh(&dn_rt_hash_table[i].lock);
}
}
SMP_TIMER_DEFINE(dn_run_flush, dn_flush_task);
static spinlock_t dn_rt_flush_lock = SPIN_LOCK_UNLOCKED;
void dn_rt_cache_flush(int delay)
{
unsigned long now = jiffies;
int user_mode = !in_interrupt();
if (delay < 0)
delay = dn_rt_min_delay;
spin_lock_bh(&dn_rt_flush_lock);
if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
long tmo = (long)(dn_rt_deadline - now);
if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
tmo = 0;
if (delay > tmo)
delay = tmo;
}
if (delay <= 0) {
spin_unlock_bh(&dn_rt_flush_lock);
dn_run_flush(0);
return;
}
if (dn_rt_deadline == 0)
dn_rt_deadline = now + dn_rt_max_delay;
dn_rt_flush_timer.expires = now + delay;
add_timer(&dn_rt_flush_timer);
spin_unlock_bh(&dn_rt_flush_lock);
}
/**
* dn_return_short - Return a short packet to its sender
* @skb: The packet to return
*
*/
static int dn_return_short(struct sk_buff *skb)
{
struct dn_skb_cb *cb;
unsigned char *ptr;
dn_address *src;
dn_address *dst;
dn_address tmp;
/* Add back headers */
skb_push(skb, skb->data - skb->nh.raw);
if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
return NET_RX_DROP;
cb = DN_SKB_CB(skb);
/* Skip packet length and point to flags */
ptr = skb->data + 2;
*ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
dst = (dn_address *)ptr;
ptr += 2;
src = (dn_address *)ptr;
ptr += 2;
*ptr = 0; /* Zero hop count */
/* Swap source and destination */
tmp = *src;
*src = *dst;
*dst = tmp;
skb->pkt_type = PACKET_OUTGOING;
dn_rt_finish_output(skb, NULL);
return NET_RX_SUCCESS;
}
/**
* dn_return_long - Return a long packet to its sender
* @skb: The long format packet to return
*
*/
static int dn_return_long(struct sk_buff *skb)
{
struct dn_skb_cb *cb;
unsigned char *ptr;
unsigned char *src_addr, *dst_addr;
unsigned char tmp[ETH_ALEN];
/* Add back all headers */
skb_push(skb, skb->data - skb->nh.raw);
if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
return NET_RX_DROP;
cb = DN_SKB_CB(skb);
/* Ignore packet length and point to flags */
ptr = skb->data + 2;
/* Skip padding */
if (*ptr & DN_RT_F_PF) {
char padlen = (*ptr & ~DN_RT_F_PF);
ptr += padlen;
}
*ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
ptr += 2;
dst_addr = ptr;
ptr += 8;
src_addr = ptr;
ptr += 6;
*ptr = 0; /* Zero hop count */
/* Swap source and destination */
memcpy(tmp, src_addr, ETH_ALEN);
memcpy(src_addr, dst_addr, ETH_ALEN);
memcpy(dst_addr, tmp, ETH_ALEN);
skb->pkt_type = PACKET_OUTGOING;
dn_rt_finish_output(skb, tmp);
return NET_RX_SUCCESS;
}
/**
* dn_route_rx_packet - Try and find a route for an incoming packet
* @skb: The packet to find a route for
*
* Returns: result of input function if route is found, error code otherwise
*/
static int dn_route_rx_packet(struct sk_buff *skb)
{
struct dn_skb_cb *cb = DN_SKB_CB(skb);
int err;
if ((err = dn_route_input(skb)) == 0)
return skb->dst->input(skb);
if (decnet_debug_level & 4) {
char *devname = skb->dev ? skb->dev->name : "???";
struct dn_skb_cb *cb = DN_SKB_CB(skb);
printk(KERN_DEBUG
"DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
(int)cb->rt_flags, devname, skb->len, cb->src, cb->dst,
err, skb->pkt_type);
}
if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
switch(cb->rt_flags & DN_RT_PKT_MSK) {
case DN_RT_PKT_SHORT:
return dn_return_short(skb);
case DN_RT_PKT_LONG:
return dn_return_long(skb);
}
}
kfree_skb(skb);
return NET_RX_DROP;
}
static int dn_route_rx_long(struct sk_buff *skb)
{
struct dn_skb_cb *cb = DN_SKB_CB(skb);
unsigned char *ptr = skb->data;
if (skb->len < 21) /* 20 for long header, 1 for shortest nsp */
goto drop_it;
skb_pull(skb, 20);
skb->h.raw = skb->data;
/* Destination info */
ptr += 2;
cb->dst = dn_htons(dn_eth2dn(ptr));
if (memcmp(ptr, dn_hiord_addr, 4) != 0)
goto drop_it;
ptr += 6;
/* Source info */
ptr += 2;
cb->src = dn_htons(dn_eth2dn(ptr));
if (memcmp(ptr, dn_hiord_addr, 4) != 0)
goto drop_it;
ptr += 6;
/* Other junk */
ptr++;
cb->hops = *ptr++; /* Visit Count */
return NF_HOOK(PF_DECnet, NF_DN_PRE_ROUTING, skb, skb->dev, NULL, dn_route_rx_packet);
drop_it:
kfree_skb(skb);
return NET_RX_DROP;
}
static int dn_route_rx_short(struct sk_buff *skb)
{
struct dn_skb_cb *cb = DN_SKB_CB(skb);
unsigned char *ptr = skb->data;
if (skb->len < 6) /* 5 for short header + 1 for shortest nsp */
goto drop_it;
skb_pull(skb, 5);
skb->h.raw = skb->data;
cb->dst = *(dn_address *)ptr;
ptr += 2;
cb->src = *(dn_address *)ptr;
ptr += 2;
cb->hops = *ptr & 0x3f;
return NF_HOOK(PF_DECnet, NF_DN_PRE_ROUTING, skb, skb->dev, NULL, dn_route_rx_packet);
drop_it:
kfree_skb(skb);
return NET_RX_DROP;
}
static int dn_route_discard(struct sk_buff *skb)
{
/*
* I know we drop the packet here, but thats considered success in
* this case
*/
kfree_skb(skb);
return NET_RX_SUCCESS;
}
static int dn_route_ptp_hello(struct sk_buff *skb)
{
dn_dev_hello(skb);
dn_neigh_pointopoint_hello(skb);
return NET_RX_SUCCESS;
}
int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
{
struct dn_skb_cb *cb;
unsigned char flags = 0;
__u16 len = dn_ntohs(*(__u16 *)skb->data);
struct dn_dev *dn = (struct dn_dev *)dev->dn_ptr;
unsigned char padlen = 0;
if (dn == NULL)
goto dump_it;
if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
goto out;
skb_pull(skb, 2);
if (len > skb->len)
goto dump_it;
skb_trim(skb, len);
flags = *skb->data;
cb = DN_SKB_CB(skb);
cb->stamp = jiffies;
cb->iif = dev->ifindex;
/*
* If we have padding, remove it.
*/
if (flags & DN_RT_F_PF) {
padlen = flags & ~DN_RT_F_PF;
skb_pull(skb, padlen);
flags = *skb->data;
}
skb->nh.raw = skb->data;
/*
* Weed out future version DECnet
*/
if (flags & DN_RT_F_VER)
goto dump_it;
cb->rt_flags = flags;
if (decnet_debug_level & 1)
printk(KERN_DEBUG
"dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
(int)flags, (dev) ? dev->name : "???", len, skb->len,
padlen);
if (flags & DN_RT_PKT_CNTL) {
switch(flags & DN_RT_CNTL_MSK) {
case DN_RT_PKT_INIT:
dn_dev_init_pkt(skb);
break;
case DN_RT_PKT_VERI:
dn_dev_veri_pkt(skb);
break;
}
if (dn->parms.state != DN_DEV_S_RU)
goto dump_it;
switch(flags & DN_RT_CNTL_MSK) {
case DN_RT_PKT_HELO:
return NF_HOOK(PF_DECnet, NF_DN_HELLO, skb, skb->dev, NULL, dn_route_ptp_hello);
case DN_RT_PKT_L1RT:
case DN_RT_PKT_L2RT:
return NF_HOOK(PF_DECnet, NF_DN_ROUTE, skb, skb->dev, NULL, dn_route_discard);
case DN_RT_PKT_ERTH:
return NF_HOOK(PF_DECnet, NF_DN_HELLO, skb, skb->dev, NULL, dn_neigh_router_hello);
case DN_RT_PKT_EEDH:
return NF_HOOK(PF_DECnet, NF_DN_HELLO, skb, skb->dev, NULL, dn_neigh_endnode_hello);
}
} else {
if (dn->parms.state != DN_DEV_S_RU)
goto dump_it;
skb_pull(skb, 1); /* Pull flags */
switch(flags & DN_RT_PKT_MSK) {
case DN_RT_PKT_LONG:
return dn_route_rx_long(skb);
case DN_RT_PKT_SHORT:
return dn_route_rx_short(skb);
}
}
dump_it:
kfree_skb(skb);
out:
return NET_RX_DROP;
}
static int dn_output(struct sk_buff *skb)
{
struct dst_entry *dst = skb->dst;
struct dn_route *rt = (struct dn_route *)dst;
struct net_device *dev = dst->dev;
struct dn_skb_cb *cb = DN_SKB_CB(skb);
struct neighbour *neigh;
int err = -EINVAL;
if ((neigh = dst->neighbour) == NULL)
goto error;
skb->dev = dev;
cb->src = rt->rt_saddr;
cb->dst = rt->rt_daddr;
/*
* Always set the Intra-Ethernet bit on all outgoing packets
* originated on this node. Only valid flag from upper layers
* is return-to-sender-requested. Set hop count to 0 too.
*/
cb->rt_flags &= ~DN_RT_F_RQR;
cb->rt_flags |= DN_RT_F_IE;
cb->hops = 0;
return NF_HOOK(PF_DECnet, NF_DN_LOCAL_OUT, skb, NULL, dev, neigh->output);
error:
if (net_ratelimit())
printk(KERN_DEBUG "dn_output: This should not happen\n");
kfree_skb(skb);
return err;
}
#ifdef CONFIG_DECNET_ROUTER
static int dn_forward(struct sk_buff *skb)
{
struct dn_skb_cb *cb = DN_SKB_CB(skb);
struct dst_entry *dst = skb->dst;
struct neighbour *neigh;
struct net_device *dev = skb->dev;
int err = -EINVAL;
if ((neigh = dst->neighbour) == NULL)
goto error;
/*
* Hop count exceeded.
*/
err = NET_RX_DROP;
if (++cb->hops > 30)
goto drop;
skb->dev = dst->dev;
/*
* If packet goes out same interface it came in on, then set
* the Intra-Ethernet bit. This has no effect for short
* packets, so we don't need to test for them here.
*/
if (cb->iif == dst->dev->ifindex)
cb->rt_flags |= DN_RT_F_IE;
else
cb->rt_flags &= ~DN_RT_F_IE;
return NF_HOOK(PF_DECnet, NF_DN_FORWARD, skb, dev, skb->dev, neigh->output);
error:
if (net_ratelimit())
printk(KERN_DEBUG "dn_forward: This should not happen\n");
drop:
kfree_skb(skb);
return err;
}
#endif
/*
* Drop packet. This is used for endnodes and for
* when we should not be forwarding packets from
* this dest.
*/
static int dn_blackhole(struct sk_buff *skb)
{
kfree_skb(skb);
return NET_RX_DROP;
}
/*
* Used to catch bugs. This should never normally get
* called.
*/
static int dn_rt_bug(struct sk_buff *skb)
{
if (net_ratelimit()) {
struct dn_skb_cb *cb = DN_SKB_CB(skb);
printk(KERN_DEBUG "dn_rt_bug: skb from:%04x to:%04x\n",
cb->src, cb->dst);
}
kfree_skb(skb);
return NET_RX_BAD;
}
static int dn_route_output_slow(struct dst_entry **pprt, dn_address dst, dn_address src, int flags)
{
struct dn_route *rt = NULL;
struct net_device *dev = decnet_default_device;
struct neighbour *neigh = NULL;
struct dn_dev *dn_db;
unsigned hash;
#ifdef CONFIG_DECNET_ROUTER
struct dn_fib_key key;
struct dn_fib_res res;
int err;
key.src = src;
key.dst = dst;
key.iif = 0;
key.oif = 0;
key.fwmark = 0;
key.scope = RT_SCOPE_UNIVERSE;
if ((err = dn_fib_lookup(&key, &res)) == 0) {
switch(res.type) {
case RTN_UNICAST:
/*
* This method of handling multipath
* routes is a hack and will change.
* It works for now though.
*/
if (res.fi->fib_nhs)
dn_fib_select_multipath(&key, &res);
neigh = __neigh_lookup(&dn_neigh_table, &DN_FIB_RES_GW(res), DN_FIB_RES_DEV(res), 1);
err = -ENOBUFS;
if (!neigh)
break;
err = 0;
break;
case RTN_UNREACHABLE:
err = -EHOSTUNREACH;
break;
default:
err = -EINVAL;
}
dn_fib_res_put(&res);
if (err < 0)
return err;
goto got_route;
}
if (err != -ESRCH)
return err;
#endif
/* Look in On-Ethernet cache first */
if (!(flags & MSG_TRYHARD)) {
if ((neigh = dn_neigh_lookup(&dn_neigh_table, &dst)) != NULL)
goto got_route;
}
if (dev == NULL)
return -EINVAL;
dn_db = dev->dn_ptr;
if (dn_db == NULL)
return -EINVAL;
/* Try default router */
if ((neigh = neigh_clone(dn_db->router)) != NULL)
goto got_route;
/* Send to default device (and hope for the best) if above fail */
if ((neigh = __neigh_lookup(&dn_neigh_table, &dst, dev, 1)) != NULL)
goto got_route;
return -EINVAL;
got_route:
if ((rt = dst_alloc(&dn_dst_ops)) == NULL) {
neigh_release(neigh);
return -EINVAL;
}
dn_db = (struct dn_dev *)neigh->dev->dn_ptr;
rt->key.saddr = src;
rt->rt_saddr = src;
rt->key.daddr = dst;
rt->rt_daddr = dst;
rt->key.oif = neigh ? neigh->dev->ifindex : -1;
rt->key.iif = 0;
rt->key.fwmark = 0;
rt->u.dst.neighbour = neigh;
rt->u.dst.dev = neigh ? neigh->dev : NULL;
rt->u.dst.lastuse = jiffies;
rt->u.dst.output = dn_output;
rt->u.dst.input = dn_rt_bug;
if (dn_dev_islocal(neigh->dev, rt->rt_daddr))
rt->u.dst.input = dn_nsp_rx;
hash = dn_hash(rt->key.saddr, rt->key.daddr);
dn_insert_route(rt, hash);
*pprt = &rt->u.dst;
return 0;
}
int dn_route_output(struct dst_entry **pprt, dn_address dst, dn_address src, int flags)
{
unsigned hash = dn_hash(src, dst);
struct dn_route *rt = NULL;
if (!(flags & MSG_TRYHARD)) {
read_lock_bh(&dn_rt_hash_table[hash].lock);
for(rt = dn_rt_hash_table[hash].chain; rt; rt = rt->u.rt_next) {
if ((dst == rt->key.daddr) &&
(src == rt->key.saddr) &&
(rt->key.iif == 0) &&
(rt->key.oif != 0)) {
rt->u.dst.lastuse = jiffies;
dst_hold(&rt->u.dst);
rt->u.dst.__use++;
read_unlock_bh(&dn_rt_hash_table[hash].lock);
*pprt = &rt->u.dst;
return 0;
}
}
read_unlock_bh(&dn_rt_hash_table[hash].lock);
}
return dn_route_output_slow(pprt, dst, src, flags);
}
static int dn_route_input_slow(struct sk_buff *skb)
{
struct dn_route *rt = NULL;
struct dn_skb_cb *cb = DN_SKB_CB(skb);
struct net_device *dev = skb->dev;
struct dn_dev *dn_db;
struct neighbour *neigh = NULL;
int (*dnrt_input)(struct sk_buff *skb);
int (*dnrt_output)(struct sk_buff *skb);
u32 fwmark = 0;
unsigned hash;
dn_address saddr = cb->src;
dn_address daddr = cb->dst;
#ifdef CONFIG_DECNET_ROUTER
struct dn_fib_key key;
struct dn_fib_res res;
int err;
#endif
if (dev == NULL)
return -EINVAL;
if ((dn_db = dev->dn_ptr) == NULL)
return -EINVAL;
/*
* In this case we've just received a packet from a source
* outside ourselves pretending to come from us. We don't
* allow it any further to prevent routing loops, spoofing and
* other nasties. Loopback packets already have the dst attached
* so this only affects packets which have originated elsewhere.
*/
if (dn_dev_islocal(dev, cb->src))
return -ENOTUNIQ;
/*
* Default is to create a drop everything entry
*/
dnrt_input = dn_blackhole;
dnrt_output = dn_rt_bug;
/*
* Is the destination us ?
*/
if (!dn_dev_islocal(dev, cb->dst))
goto non_local_input;
/*
* Local input... find source of skb
*/
dnrt_input = dn_nsp_rx;
dnrt_output = dn_output;
saddr = cb->dst;
daddr = cb->src;
if ((neigh = neigh_lookup(&dn_neigh_table, &cb->src, dev)) != NULL)
goto add_entry;
if (dn_db->router && ((neigh = neigh_clone(dn_db->router)) != NULL))
goto add_entry;
neigh = neigh_create(&dn_neigh_table, &cb->src, dev);
if (!IS_ERR(neigh)) {
if (dev->type == ARPHRD_ETHER)
memcpy(neigh->ha, skb->mac.ethernet->h_source, ETH_ALEN);
goto add_entry;
}
return PTR_ERR(neigh);
non_local_input:
#ifdef CONFIG_DECNET_ROUTER
/*
* Destination is another node... find next hop in
* routing table here.
*/
key.src = cb->src;
key.dst = cb->dst;
key.iif = dev->ifindex;
key.oif = 0;
key.scope = RT_SCOPE_UNIVERSE;
#ifdef CONFIG_DECNET_ROUTE_FWMARK
key.fwmark = skb->nfmark;
#else
key.fwmark = 0;
#endif
if ((err = dn_fib_lookup(&key, &res)) == 0) {
switch(res.type) {
case RTN_UNICAST:
if (res.fi->fib_nhs)
dn_fib_select_multipath(&key, &res);
neigh = __neigh_lookup(&dn_neigh_table, &DN_FIB_RES_GW(res), DN_FIB_RES_DEV(res), 1);
err = -ENOBUFS;
if (!neigh)
break;
err = 0;
dnrt_input = dn_forward;
fwmark = key.fwmark;
break;
case RTN_UNREACHABLE:
dnrt_input = dn_blackhole;
fwmark = key.fwmark;
break;
default:
err = -EINVAL;
}
dn_fib_res_put(&res);
if (err < 0)
return err;
goto add_entry;
}
return err;
#endif /* CONFIG_DECNET_ROUTER */
add_entry:
if ((rt = dst_alloc(&dn_dst_ops)) == NULL) {
neigh_release(neigh);
return -EINVAL;
}
rt->key.saddr = cb->src;
rt->rt_saddr = saddr;
rt->key.daddr = cb->dst;
rt->rt_daddr = daddr;
rt->key.oif = 0;
rt->key.iif = dev->ifindex;
rt->key.fwmark = fwmark;
rt->u.dst.neighbour = neigh;
rt->u.dst.dev = neigh ? neigh->dev : NULL;
rt->u.dst.lastuse = jiffies;
rt->u.dst.output = dnrt_output;
rt->u.dst.input = dnrt_input;
hash = dn_hash(rt->key.saddr, rt->key.daddr);
dn_insert_route(rt, hash);
skb->dst = (struct dst_entry *)rt;
return 0;
}
int dn_route_input(struct sk_buff *skb)
{
struct dn_route *rt;
struct dn_skb_cb *cb = DN_SKB_CB(skb);
unsigned hash = dn_hash(cb->src, cb->dst);
if (skb->dst)
return 0;
read_lock(&dn_rt_hash_table[hash].lock);
for(rt = dn_rt_hash_table[hash].chain; rt != NULL; rt = rt->u.rt_next) {
if ((rt->key.saddr == cb->src) &&
(rt->key.daddr == cb->dst) &&
(rt->key.oif == 0) &&
#ifdef CONFIG_DECNET_ROUTE_FWMARK
(rt->key.fwmark == skb->nfmark) &&
#endif
(rt->key.iif == cb->iif)) {
rt->u.dst.lastuse = jiffies;
dst_hold(&rt->u.dst);
rt->u.dst.__use++;
read_unlock(&dn_rt_hash_table[hash].lock);
skb->dst = (struct dst_entry *)rt;
return 0;
}
}
read_unlock(&dn_rt_hash_table[hash].lock);
return dn_route_input_slow(skb);
}
static int dn_rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event, int nowait)
{
struct dn_route *rt = (struct dn_route *)skb->dst;
struct rtmsg *r;
struct nlmsghdr *nlh;
unsigned char *b = skb->tail;
nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*r));
r = NLMSG_DATA(nlh);
nlh->nlmsg_flags = nowait ? NLM_F_MULTI : 0;
r->rtm_family = AF_DECnet;
r->rtm_dst_len = 16;
r->rtm_src_len = 16;
r->rtm_tos = 0;
r->rtm_table = 0;
r->rtm_type = 0;
r->rtm_flags = 0;
r->rtm_scope = RT_SCOPE_UNIVERSE;
r->rtm_protocol = RTPROT_UNSPEC;
RTA_PUT(skb, RTA_DST, 2, &rt->rt_daddr);
RTA_PUT(skb, RTA_SRC, 2, &rt->rt_saddr);
if (rt->u.dst.dev)
RTA_PUT(skb, RTA_OIF, sizeof(int), &rt->u.dst.dev->ifindex);
if (rt->u.dst.window)
RTA_PUT(skb, RTAX_WINDOW, sizeof(unsigned), &rt->u.dst.window);
if (rt->u.dst.rtt)
RTA_PUT(skb, RTAX_RTT, sizeof(unsigned), &rt->u.dst.rtt);
nlh->nlmsg_len = skb->tail - b;
return skb->len;
nlmsg_failure:
rtattr_failure:
skb_trim(skb, b - skb->data);
return -1;
}
/*
* This is called by both endnodes and routers now.
*/
int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
{
struct rtattr **rta = arg;
struct dn_route *rt = NULL;
struct dn_skb_cb *cb;
dn_address dst = 0;
dn_address src = 0;
int iif = 0;
int err;
struct sk_buff *skb;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (skb == NULL)
return -ENOBUFS;
skb->mac.raw = skb->data;
cb = DN_SKB_CB(skb);
if (rta[RTA_SRC-1])
memcpy(&src, RTA_DATA(rta[RTA_SRC-1]), 2);
if (rta[RTA_DST-1])
memcpy(&dst, RTA_DATA(rta[RTA_DST-1]), 2);
if (rta[RTA_IIF-1])
memcpy(&iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int));
if (iif) {
struct net_device *dev;
if ((dev = dev_get_by_index(iif)) == NULL) {
kfree_skb(skb);
return -ENODEV;
}
if (!dev->dn_ptr) {
dev_put(dev);
kfree_skb(skb);
return -ENODEV;
}
skb->protocol = __constant_htons(ETH_P_DNA_RT);
skb->dev = dev;
cb->src = src;
cb->dst = dst;
local_bh_disable();
err = dn_route_input(skb);
local_bh_enable();
memset(cb, 0, sizeof(struct dn_skb_cb));
rt = (struct dn_route *)skb->dst;
} else {
err = dn_route_output((struct dst_entry **)&rt, dst, src, 0);
}
if (!err && rt->u.dst.error)
err = rt->u.dst.error;
if (skb->dev)
dev_put(skb->dev);
skb->dev = NULL;
if (err)
goto out_free;
skb->dst = &rt->u.dst;
NETLINK_CB(skb).dst_pid = NETLINK_CB(in_skb).pid;
err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, RTM_NEWROUTE, 0);
if (err == 0)
goto out_free;
if (err < 0) {
err = -EMSGSIZE;
goto out_free;
}
err = netlink_unicast(rtnl, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
return err;
out_free:
kfree_skb(skb);
return err;
}
/*
* For routers, this is called from dn_fib_dump, but for endnodes its
* called directly from the rtnetlink dispatch table.
*/
int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
struct dn_route *rt;
int h, s_h;
int idx, s_idx;
if (NLMSG_PAYLOAD(cb->nlh, 0) < sizeof(struct rtmsg))
return -EINVAL;
if (!(((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED))
return 0;
s_h = cb->args[0];
s_idx = idx = cb->args[1];
for(h = 0; h <= dn_rt_hash_mask; h++) {
if (h < s_h)
continue;
if (h > s_h)
s_idx = 0;
read_lock_bh(&dn_rt_hash_table[h].lock);
for(rt = dn_rt_hash_table[h].chain, idx = 0; rt; rt = rt->u.rt_next, idx++) {
if (idx < s_idx)
continue;
skb->dst = dst_clone(&rt->u.dst);
if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq, RTM_NEWROUTE, 1) <= 0) {
dst_release(xchg(&skb->dst, NULL));
read_unlock_bh(&dn_rt_hash_table[h].lock);
goto done;
}
dst_release(xchg(&skb->dst, NULL));
}
read_unlock_bh(&dn_rt_hash_table[h].lock);
}
done:
cb->args[0] = h;
cb->args[1] = idx;
return skb->len;
}
#ifdef CONFIG_PROC_FS
static int decnet_cache_get_info(char *buffer, char **start, off_t offset, int length)
{
int len = 0;
off_t pos = 0;
off_t begin = 0;
struct dn_route *rt;
int i;
char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
for(i = 0; i <= dn_rt_hash_mask; i++) {
read_lock_bh(&dn_rt_hash_table[i].lock);
rt = dn_rt_hash_table[i].chain;
for(; rt != NULL; rt = rt->u.rt_next) {
len += sprintf(buffer + len, "%-8s %-7s %-7s %04d %04d %04d\n",
rt->u.dst.dev ? rt->u.dst.dev->name : "*",
dn_addr2asc(dn_ntohs(rt->rt_daddr), buf1),
dn_addr2asc(dn_ntohs(rt->rt_saddr), buf2),
atomic_read(&rt->u.dst.__refcnt),
rt->u.dst.__use,
(int)rt->u.dst.rtt
);
pos = begin + len;
if (pos < offset) {
len = 0;
begin = pos;
}
if (pos > offset + length)
break;
}
read_unlock_bh(&dn_rt_hash_table[i].lock);
if (pos > offset + length)
break;
}
*start = buffer + (offset - begin);
len -= (offset - begin);
if (len > length) len = length;
return(len);
}
#endif /* CONFIG_PROC_FS */
void __init dn_route_init(void)
{
int i, goal, order;
dn_dst_ops.kmem_cachep = kmem_cache_create("dn_dst_cache",
sizeof(struct dn_route),
0, SLAB_HWCACHE_ALIGN,
NULL, NULL);
if (!dn_dst_ops.kmem_cachep)
panic("DECnet: Failed to allocate dn_dst_cache\n");
dn_route_timer.function = dn_dst_check_expire;
dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
add_timer(&dn_route_timer);
goal = num_physpages >> (26 - PAGE_SHIFT);
for(order = 0; (1UL << order) < goal; order++)
/* NOTHING */;
/*
* Only want 1024 entries max, since the table is very, very unlikely
* to be larger than that.
*/
while(order && ((((1UL << order) * PAGE_SIZE) /
sizeof(struct dn_rt_hash_bucket)) >= 2048))
order--;
do {
dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
sizeof(struct dn_rt_hash_bucket);
while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
dn_rt_hash_mask--;
dn_rt_hash_table = (struct dn_rt_hash_bucket *)
__get_free_pages(GFP_ATOMIC, order);
} while (dn_rt_hash_table == NULL && --order > 0);
if (!dn_rt_hash_table)
panic("Failed to allocate DECnet route cache hash table\n");
printk(KERN_INFO
"DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
dn_rt_hash_mask,
(long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
dn_rt_hash_mask--;
for(i = 0; i <= dn_rt_hash_mask; i++) {
dn_rt_hash_table[i].lock = RW_LOCK_UNLOCKED;
dn_rt_hash_table[i].chain = NULL;
}
dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
#ifdef CONFIG_PROC_FS
proc_net_create("decnet_cache",0,decnet_cache_get_info);
#endif /* CONFIG_PROC_FS */
}
void __exit dn_route_cleanup(void)
{
del_timer(&dn_route_timer);
dn_run_flush(0);
proc_net_remove("decnet_cache");
}
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