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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [net/] [decnet/] [dn_route.c] - Blame information for rev 1765

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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.
 *              Steve Whitehouse : Fixed bug where routes were set up with
 *                                 no ref count on net devices.
 *
 */
 
/******************************************************************************
    (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;
        if (rt->u.dst.dev)
                dev_hold(rt->u.dst.dev);
        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;
        if (rt->u.dst.dev)
                dev_hold(rt->u.dst.dev);
        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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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [net/] [decnet/] [dn_route.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	1275	phoenix
2			`/*`
3			`* DECnet An implementation of the DECnet protocol suite for the LINUX`
4			`* operating system. DECnet is implemented using the BSD Socket`
5			`* interface as the means of communication with the user level.`
6			`*`
7			`* DECnet Routing Functions (Endnode and Router)`
8			`*`
9			`* Authors: Steve Whitehouse <SteveW@ACM.org>`
10			`* Eduardo Marcelo Serrat <emserrat@geocities.com>`
11			`*`
12			`* Changes:`
13			`* Steve Whitehouse : Fixes to allow "intra-ethernet" and`
14			`* "return-to-sender" bits on outgoing`
15			`* packets.`
16			`* Steve Whitehouse : Timeouts for cached routes.`
17			`* Steve Whitehouse : Use dst cache for input routes too.`
18			`* Steve Whitehouse : Fixed error values in dn_send_skb.`
19			`* Steve Whitehouse : Rework routing functions to better fit`
20			`* DECnet routing design`
21			`* Alexey Kuznetsov : New SMP locking`
22			`* Steve Whitehouse : More SMP locking changes & dn_cache_dump()`
23			`* Steve Whitehouse : Prerouting NF hook, now really is prerouting.`
24			`* Fixed possible skb leak in rtnetlink funcs.`
25			`* Steve Whitehouse : Dave Miller's dynamic hash table sizing and`
26			`* Alexey Kuznetsov's finer grained locking`
27			`* from ipv4/route.c.`
28			`* Steve Whitehouse : Routing is now starting to look like a`
29			`* sensible set of code now, mainly due to`
30			`* my copying the IPv4 routing code. The`
31			`* hooks here are modified and will continue`
32			`* to evolve for a while.`
33			`* Steve Whitehouse : Real SMP at last :-) Also new netfilter`
34			`* stuff. Look out raw sockets your days`
35			`* are numbered!`
36			`* Steve Whitehouse : Added return-to-sender functions. Added`
37			`* backlog congestion level return codes.`
38			`* Steve Whitehouse : Fixed bug where routes were set up with`
39			`* no ref count on net devices.`
40			`*`