1 files changed, 825 insertions, 0 deletions

diff --git a/net/decnet/dn_table.c b/net/decnet/dn_table.c
new file mode 100644
index 000000000000..dad5603912be
--- /dev/null
+++ b/net/decnet/dn_table.c
@@ -0,0 +1,825 @@
+/*
+ * 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 Forwarding Information Base (Routing Tables)
+ *
+ * Author:      Steve Whitehouse <SteveW@ACM.org>
+ *              Mostly copied from the IPv4 routing code
+ *
+ *
+ * Changes:
+ *
+ */
+#include <linux/config.h>
+#include <linux/string.h>
+#include <linux/net.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <linux/proc_fs.h>
+#include <linux/netdevice.h>
+#include <linux/timer.h>
+#include <linux/spinlock.h>
+#include <asm/atomic.h>
+#include <asm/uaccess.h>
+#include <linux/route.h> /* RTF_xxx */
+#include <net/neighbour.h>
+#include <net/dst.h>
+#include <net/flow.h>
+#include <net/dn.h>
+#include <net/dn_route.h>
+#include <net/dn_fib.h>
+#include <net/dn_neigh.h>
+#include <net/dn_dev.h>
+
+struct dn_zone
+{
+	struct dn_zone		*dz_next;
+	struct dn_fib_node 	**dz_hash;
+	int			dz_nent;
+	int			dz_divisor;
+	u32			dz_hashmask;
+#define DZ_HASHMASK(dz)	((dz)->dz_hashmask)
+	int			dz_order;
+	u16			dz_mask;
+#define DZ_MASK(dz)	((dz)->dz_mask)
+};
+
+struct dn_hash
+{
+	struct dn_zone	*dh_zones[17];
+	struct dn_zone	*dh_zone_list;
+};
+
+#define dz_key_0(key)		((key).datum = 0)
+#define dz_prefix(key,dz)	((key).datum)
+
+#define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
+        for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
+
+#define endfor_nexthops(fi) }
+
+#define DN_MAX_DIVISOR 1024
+#define DN_S_ZOMBIE 1
+#define DN_S_ACCESSED 2
+
+#define DN_FIB_SCAN(f, fp) \
+for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
+
+#define DN_FIB_SCAN_KEY(f, fp, key) \
+for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
+
+#define RT_TABLE_MIN 1
+
+static DEFINE_RWLOCK(dn_fib_tables_lock);
+struct dn_fib_table *dn_fib_tables[RT_TABLE_MAX + 1];
+
+static kmem_cache_t *dn_hash_kmem;
+static int dn_fib_hash_zombies;
+
+static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
+{
+	u16 h = ntohs(key.datum)>>(16 - dz->dz_order);
+	h ^= (h >> 10);
+	h ^= (h >> 6);
+	h &= DZ_HASHMASK(dz);
+	return *(dn_fib_idx_t *)&h;
+}
+
+static inline dn_fib_key_t dz_key(u16 dst, struct dn_zone *dz)
+{
+	dn_fib_key_t k;
+	k.datum = dst & DZ_MASK(dz);
+	return k;
+}
+
+static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
+{
+	return &dz->dz_hash[dn_hash(key, dz).datum];
+}
+
+static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
+{
+	return dz->dz_hash[dn_hash(key, dz).datum];
+}
+
+static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
+{
+	return a.datum == b.datum;
+}
+
+static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
+{
+	return a.datum <= b.datum;
+}
+
+static inline void dn_rebuild_zone(struct dn_zone *dz,
+				   struct dn_fib_node **old_ht,
+				   int old_divisor)
+{
+	int i;
+	struct dn_fib_node *f, **fp, *next;
+
+	for(i = 0; i < old_divisor; i++) {
+		for(f = old_ht[i]; f; f = f->fn_next) {
+			next = f->fn_next;
+			for(fp = dn_chain_p(f->fn_key, dz);
+				*fp && dn_key_leq((*fp)->fn_key, f->fn_key);
+				fp = &(*fp)->fn_next)
+				/* NOTHING */;
+			f->fn_next = *fp;
+			*fp = f;
+		}
+	}
+}
+
+static void dn_rehash_zone(struct dn_zone *dz)
+{
+	struct dn_fib_node **ht, **old_ht;
+	int old_divisor, new_divisor;
+	u32 new_hashmask;
+
+	old_divisor = dz->dz_divisor;
+
+	switch(old_divisor) {
+		case 16:
+			new_divisor = 256;
+			new_hashmask = 0xFF;
+			break;
+		default:
+			printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n", old_divisor);
+		case 256:
+			new_divisor = 1024;
+			new_hashmask = 0x3FF;
+			break;
+	}
+
+	ht = kmalloc(new_divisor*sizeof(struct dn_fib_node*), GFP_KERNEL);
+
+	if (ht == NULL)
+		return;
+
+	memset(ht, 0, new_divisor*sizeof(struct dn_fib_node *));
+	write_lock_bh(&dn_fib_tables_lock);
+	old_ht = dz->dz_hash;
+	dz->dz_hash = ht;
+	dz->dz_hashmask = new_hashmask;
+	dz->dz_divisor = new_divisor;
+	dn_rebuild_zone(dz, old_ht, old_divisor);
+	write_unlock_bh(&dn_fib_tables_lock);
+	kfree(old_ht);
+}
+
+static void dn_free_node(struct dn_fib_node *f)
+{
+	dn_fib_release_info(DN_FIB_INFO(f));
+	kmem_cache_free(dn_hash_kmem, f);
+}
+
+
+static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
+{
+	int i;
+	struct dn_zone *dz = kmalloc(sizeof(struct dn_zone), GFP_KERNEL);
+	if (!dz)
+		return NULL;
+
+	memset(dz, 0, sizeof(struct dn_zone));
+	if (z) {
+		dz->dz_divisor = 16;
+		dz->dz_hashmask = 0x0F;
+	} else {
+		dz->dz_divisor = 1;
+		dz->dz_hashmask = 0;
+	}
+
+	dz->dz_hash = kmalloc(dz->dz_divisor*sizeof(struct dn_fib_node *), GFP_KERNEL);
+
+	if (!dz->dz_hash) {
+		kfree(dz);
+		return NULL;
+	}
+
+	memset(dz->dz_hash, 0, dz->dz_divisor*sizeof(struct dn_fib_node*));
+	dz->dz_order = z;
+	dz->dz_mask = dnet_make_mask(z);
+
+	for(i = z + 1; i <= 16; i++)
+		if (table->dh_zones[i])
+			break;
+
+	write_lock_bh(&dn_fib_tables_lock);
+	if (i>16) {
+		dz->dz_next = table->dh_zone_list;
+		table->dh_zone_list = dz;
+	} else {
+		dz->dz_next = table->dh_zones[i]->dz_next;
+		table->dh_zones[i]->dz_next = dz;
+	}
+	table->dh_zones[z] = dz;
+	write_unlock_bh(&dn_fib_tables_lock);
+	return dz;
+}
+
+
+static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
+{
+	struct rtnexthop *nhp;
+	int nhlen;
+
+	if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
+		return 1;
+
+	if (rta->rta_oif || rta->rta_gw) {
+		if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
+		    (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
+			return 0;
+		return 1;
+	}
+
+	if (rta->rta_mp == NULL)
+		return 0;
+
+	nhp = RTA_DATA(rta->rta_mp);
+	nhlen = RTA_PAYLOAD(rta->rta_mp);
+
+	for_nexthops(fi) {
+		int attrlen = nhlen - sizeof(struct rtnexthop);
+		dn_address gw;
+
+		if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
+			return -EINVAL;
+		if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
+			return 1;
+		if (attrlen) {
+			gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
+
+			if (gw && gw != nh->nh_gw)
+				return 1;
+		}
+		nhp = RTNH_NEXT(nhp);
+	} endfor_nexthops(fi);
+
+	return 0;
+}
+
+static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
+                        u8 tb_id, u8 type, u8 scope, void *dst, int dst_len,
+                        struct dn_fib_info *fi)
+{
+        struct rtmsg *rtm;
+        struct nlmsghdr *nlh;
+        unsigned char *b = skb->tail;
+
+        nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*rtm));
+        rtm = NLMSG_DATA(nlh);
+        rtm->rtm_family = AF_DECnet;
+        rtm->rtm_dst_len = dst_len;
+        rtm->rtm_src_len = 0;
+        rtm->rtm_tos = 0;
+        rtm->rtm_table = tb_id;
+        rtm->rtm_flags = fi->fib_flags;
+        rtm->rtm_scope = scope;
+	rtm->rtm_type  = type;
+        if (rtm->rtm_dst_len)
+                RTA_PUT(skb, RTA_DST, 2, dst);
+        rtm->rtm_protocol = fi->fib_protocol;
+        if (fi->fib_priority)
+                RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
+	if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
+		goto rtattr_failure;
+        if (fi->fib_nhs == 1) {
+                if (fi->fib_nh->nh_gw)
+                        RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
+                if (fi->fib_nh->nh_oif)
+                        RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
+        }
+        if (fi->fib_nhs > 1) {
+                struct rtnexthop *nhp;
+                struct rtattr *mp_head;
+                if (skb_tailroom(skb) <= RTA_SPACE(0))
+                        goto rtattr_failure;
+                mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
+
+                for_nexthops(fi) {
+                        if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
+                                goto rtattr_failure;
+                        nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
+                        nhp->rtnh_flags = nh->nh_flags & 0xFF;
+                        nhp->rtnh_hops = nh->nh_weight - 1;
+                        nhp->rtnh_ifindex = nh->nh_oif;
+                        if (nh->nh_gw)
+                                RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
+                        nhp->rtnh_len = skb->tail - (unsigned char *)nhp;
+                } endfor_nexthops(fi);
+                mp_head->rta_type = RTA_MULTIPATH;
+                mp_head->rta_len = skb->tail - (u8*)mp_head;
+        }
+
+        nlh->nlmsg_len = skb->tail - b;
+        return skb->len;
+
+
+nlmsg_failure:
+rtattr_failure:
+        skb_trim(skb, b - skb->data);
+        return -1;
+}
+
+
+static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, int tb_id,
+                        struct nlmsghdr *nlh, struct netlink_skb_parms *req)
+{
+        struct sk_buff *skb;
+        u32 pid = req ? req->pid : 0;
+        int size = NLMSG_SPACE(sizeof(struct rtmsg) + 256);
+
+        skb = alloc_skb(size, GFP_KERNEL);
+        if (!skb)
+                return;
+
+        if (dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id, 
+                                f->fn_type, f->fn_scope, &f->fn_key, z, 
+                                DN_FIB_INFO(f)) < 0) {
+                kfree_skb(skb);
+                return;
+        }
+        NETLINK_CB(skb).dst_groups = RTMGRP_DECnet_ROUTE;
+        if (nlh->nlmsg_flags & NLM_F_ECHO)
+                atomic_inc(&skb->users);
+        netlink_broadcast(rtnl, skb, pid, RTMGRP_DECnet_ROUTE, GFP_KERNEL);
+        if (nlh->nlmsg_flags & NLM_F_ECHO)
+                netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
+}
+
+static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb, 
+				struct netlink_callback *cb,
+				struct dn_fib_table *tb,
+				struct dn_zone *dz,
+				struct dn_fib_node *f)
+{
+	int i, s_i;
+
+	s_i = cb->args[3];
+	for(i = 0; f; i++, f = f->fn_next) {
+		if (i < s_i)
+			continue;
+		if (f->fn_state & DN_S_ZOMBIE)
+			continue;
+		if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid, 
+				cb->nlh->nlmsg_seq,
+				RTM_NEWROUTE,
+				tb->n, 
+				(f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
+				f->fn_scope, &f->fn_key, dz->dz_order, 
+				f->fn_info) < 0) {
+			cb->args[3] = i;
+			return -1;
+		}
+	}
+	cb->args[3] = i;
+	return skb->len;
+}
+
+static __inline__ int dn_hash_dump_zone(struct sk_buff *skb, 
+				struct netlink_callback *cb,
+				struct dn_fib_table *tb,
+				struct dn_zone *dz)
+{
+	int h, s_h;
+
+	s_h = cb->args[2];
+	for(h = 0; h < dz->dz_divisor; h++) {
+		if (h < s_h)
+			continue;
+		if (h > s_h)
+			memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
+		if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
+			continue;
+		if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
+			cb->args[2] = h;
+			return -1;
+		}
+	}
+	cb->args[2] = h;
+	return skb->len;
+}
+
+static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb, 
+                                struct netlink_callback *cb)
+{
+        int m, s_m;
+	struct dn_zone *dz;
+	struct dn_hash *table = (struct dn_hash *)tb->data;
+
+	s_m = cb->args[1];
+	read_lock(&dn_fib_tables_lock);
+	for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
+		if (m < s_m)
+			continue;
+		if (m > s_m)
+			memset(&cb->args[2], 0, sizeof(cb->args) - 2*sizeof(cb->args[0]));
+
+		if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
+			cb->args[1] = m;
+			read_unlock(&dn_fib_tables_lock);
+			return -1;
+		}
+	}
+	read_unlock(&dn_fib_tables_lock);
+	cb->args[1] = m;
+
+        return skb->len;
+}
+
+static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
+{
+	struct dn_hash *table = (struct dn_hash *)tb->data;
+	struct dn_fib_node *new_f, *f, **fp, **del_fp;
+	struct dn_zone *dz;
+	struct dn_fib_info *fi;
+        int z = r->rtm_dst_len;
+	int type = r->rtm_type;
+	dn_fib_key_t key;
+        int err;
+
+        if (z > 16)
+                return -EINVAL;
+
+	dz = table->dh_zones[z];
+	if (!dz && !(dz = dn_new_zone(table, z)))
+		return -ENOBUFS;
+
+	dz_key_0(key);
+	if (rta->rta_dst) {
+		dn_address dst;
+		memcpy(&dst, rta->rta_dst, 2);
+		if (dst & ~DZ_MASK(dz))
+			return -EINVAL;
+		key = dz_key(dst, dz);
+	}
+
+        if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
+                return err;
+
+	if (dz->dz_nent > (dz->dz_divisor << 2) &&
+			dz->dz_divisor > DN_MAX_DIVISOR &&
+			(z==16 || (1<<z) > dz->dz_divisor))
+		dn_rehash_zone(dz);
+
+	fp = dn_chain_p(key, dz);
+
+	DN_FIB_SCAN(f, fp) {
+		if (dn_key_leq(key, f->fn_key))
+			break;
+	}
+
+	del_fp = NULL;
+
+	if (f && (f->fn_state & DN_S_ZOMBIE) &&
+			dn_key_eq(f->fn_key, key)) {
+		del_fp = fp;
+		fp = &f->fn_next;
+		f = *fp;
+		goto create;
+	}
+
+	DN_FIB_SCAN_KEY(f, fp, key) {
+		if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
+			break;
+	}
+
+	if (f && dn_key_eq(f->fn_key, key) &&
+			fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
+		struct dn_fib_node **ins_fp;
+
+		err = -EEXIST;
+		if (n->nlmsg_flags & NLM_F_EXCL)
+			goto out;
+
+		if (n->nlmsg_flags & NLM_F_REPLACE) {
+			del_fp = fp;
+			fp = &f->fn_next;
+			f = *fp;
+			goto replace;
+		}
+
+		ins_fp = fp;
+		err = -EEXIST;
+
+		DN_FIB_SCAN_KEY(f, fp, key) {
+			if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
+				break;
+			if (f->fn_type == type && f->fn_scope == r->rtm_scope
+					&& DN_FIB_INFO(f) == fi)
+				goto out;
+		}
+
+		if (!(n->nlmsg_flags & NLM_F_APPEND)) {
+			fp = ins_fp;
+			f = *fp;
+		}
+	}
+
+create:
+	err = -ENOENT;
+	if (!(n->nlmsg_flags & NLM_F_CREATE))
+		goto out;
+
+replace:
+	err = -ENOBUFS;
+	new_f = kmem_cache_alloc(dn_hash_kmem, SLAB_KERNEL);
+	if (new_f == NULL)
+		goto out;
+
+	memset(new_f, 0, sizeof(struct dn_fib_node));
+
+	new_f->fn_key = key;
+	new_f->fn_type = type;
+	new_f->fn_scope = r->rtm_scope;
+	DN_FIB_INFO(new_f) = fi;
+
+	new_f->fn_next = f;
+	write_lock_bh(&dn_fib_tables_lock);
+	*fp = new_f;
+	write_unlock_bh(&dn_fib_tables_lock);
+	dz->dz_nent++;
+
+	if (del_fp) {
+		f = *del_fp;
+		write_lock_bh(&dn_fib_tables_lock);
+		*del_fp = f->fn_next;
+		write_unlock_bh(&dn_fib_tables_lock);
+
+		if (!(f->fn_state & DN_S_ZOMBIE))
+			dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
+		if (f->fn_state & DN_S_ACCESSED)
+			dn_rt_cache_flush(-1);
+		dn_free_node(f);
+		dz->dz_nent--;
+	} else {
+		dn_rt_cache_flush(-1);
+	}
+
+        dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
+
+        return 0;
+out:
+	dn_fib_release_info(fi);
+	return err;
+}
+
+
+static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
+{
+	struct dn_hash *table = (struct dn_hash*)tb->data;
+	struct dn_fib_node **fp, **del_fp, *f;
+        int z = r->rtm_dst_len;
+	struct dn_zone *dz;
+	dn_fib_key_t key;
+	int matched;
+
+
+        if (z > 16)
+                return -EINVAL;
+
+	if ((dz = table->dh_zones[z]) == NULL)
+		return -ESRCH;
+
+	dz_key_0(key);
+	if (rta->rta_dst) {
+		dn_address dst;
+		memcpy(&dst, rta->rta_dst, 2);
+		if (dst & ~DZ_MASK(dz))
+			return -EINVAL;
+		key = dz_key(dst, dz);
+	}
+
+	fp = dn_chain_p(key, dz);
+
+	DN_FIB_SCAN(f, fp) {
+		if (dn_key_eq(f->fn_key, key))
+			break;
+		if (dn_key_leq(key, f->fn_key))
+			return -ESRCH;
+	}
+
+	matched = 0;
+	del_fp = NULL;
+	DN_FIB_SCAN_KEY(f, fp, key) {
+		struct dn_fib_info *fi = DN_FIB_INFO(f);
+
+		if (f->fn_state & DN_S_ZOMBIE)
+			return -ESRCH;
+
+		matched++;
+
+		if (del_fp == NULL &&
+				(!r->rtm_type || f->fn_type == r->rtm_type) &&
+				(r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
+				(!r->rtm_protocol || 
+					fi->fib_protocol == r->rtm_protocol) &&
+				dn_fib_nh_match(r, n, rta, fi) == 0)
+			del_fp = fp;
+	}
+
+	if (del_fp) {
+		f = *del_fp;
+        	dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
+
+		if (matched != 1) {
+			write_lock_bh(&dn_fib_tables_lock);
+			*del_fp = f->fn_next;
+			write_unlock_bh(&dn_fib_tables_lock);
+
+			if (f->fn_state & DN_S_ACCESSED)
+				dn_rt_cache_flush(-1);
+			dn_free_node(f);
+			dz->dz_nent--;
+		} else {
+			f->fn_state |= DN_S_ZOMBIE;
+			if (f->fn_state & DN_S_ACCESSED) {
+				f->fn_state &= ~DN_S_ACCESSED;
+				dn_rt_cache_flush(-1);
+			}
+			if (++dn_fib_hash_zombies > 128)
+				dn_fib_flush();
+		}
+
+		return 0;
+	}
+
+        return -ESRCH;
+}
+
+static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
+{
+	int found = 0;
+	struct dn_fib_node *f;
+
+	while((f = *fp) != NULL) {
+		struct dn_fib_info *fi = DN_FIB_INFO(f);
+
+		if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
+			write_lock_bh(&dn_fib_tables_lock);
+			*fp = f->fn_next;
+			write_unlock_bh(&dn_fib_tables_lock);
+
+			dn_free_node(f);
+			found++;
+			continue;
+		}
+		fp = &f->fn_next;
+	}
+
+	return found;
+}
+
+static int dn_fib_table_flush(struct dn_fib_table *tb)
+{
+	struct dn_hash *table = (struct dn_hash *)tb->data;
+	struct dn_zone *dz;
+	int found = 0;
+
+	dn_fib_hash_zombies = 0;
+	for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
+		int i;
+		int tmp = 0;
+		for(i = dz->dz_divisor-1; i >= 0; i--)
+			tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
+		dz->dz_nent -= tmp;
+		found += tmp;
+	}
+
+	return found;
+}
+
+static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
+{
+        int err;
+	struct dn_zone *dz;
+	struct dn_hash *t = (struct dn_hash *)tb->data;
+
+	read_lock(&dn_fib_tables_lock);
+	for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
+		struct dn_fib_node *f;
+		dn_fib_key_t k = dz_key(flp->fld_dst, dz);
+
+		for(f = dz_chain(k, dz); f; f = f->fn_next) {
+			if (!dn_key_eq(k, f->fn_key)) {
+				if (dn_key_leq(k, f->fn_key))
+					break;
+				else
+					continue;
+			}
+
+			f->fn_state |= DN_S_ACCESSED;
+
+			if (f->fn_state&DN_S_ZOMBIE)
+				continue;
+
+			if (f->fn_scope < flp->fld_scope)
+				continue;
+
+			err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
+
+			if (err == 0) {
+				res->type = f->fn_type;
+				res->scope = f->fn_scope; 
+				res->prefixlen = dz->dz_order;
+				goto out;
+			}
+			if (err < 0)
+				goto out;
+		}
+	}
+	err = 1;
+out:
+	read_unlock(&dn_fib_tables_lock);
+        return err;
+}
+
+
+struct dn_fib_table *dn_fib_get_table(int n, int create)
+{
+        struct dn_fib_table *t;
+
+        if (n < RT_TABLE_MIN)
+                return NULL;
+
+        if (n > RT_TABLE_MAX)
+                return NULL;
+
+        if (dn_fib_tables[n]) 
+                return dn_fib_tables[n];
+
+        if (!create)
+                return NULL;
+
+        if (in_interrupt() && net_ratelimit()) {
+                printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n"); 
+                return NULL;
+        }
+        if ((t = kmalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash), GFP_KERNEL)) == NULL)
+                return NULL;
+
+        memset(t, 0, sizeof(struct dn_fib_table));
+
+        t->n = n;
+        t->insert = dn_fib_table_insert;
+        t->delete = dn_fib_table_delete;
+        t->lookup = dn_fib_table_lookup;
+        t->flush  = dn_fib_table_flush;
+        t->dump = dn_fib_table_dump;
+	memset(t->data, 0, sizeof(struct dn_hash));
+        dn_fib_tables[n] = t;
+
+        return t;
+}
+
+static void dn_fib_del_tree(int n)
+{
+        struct dn_fib_table *t;
+
+        write_lock(&dn_fib_tables_lock);
+        t = dn_fib_tables[n];
+        dn_fib_tables[n] = NULL;
+        write_unlock(&dn_fib_tables_lock);
+
+        if (t) {
+                kfree(t);
+        }
+}
+
+struct dn_fib_table *dn_fib_empty_table(void)
+{
+        int id;
+
+        for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
+                if (dn_fib_tables[id] == NULL)
+                        return dn_fib_get_table(id, 1);
+        return NULL;
+}
+
+void __init dn_fib_table_init(void)
+{
+	dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
+					sizeof(struct dn_fib_info),
+					0, SLAB_HWCACHE_ALIGN,
+					NULL, NULL);
+}
+
+void __exit dn_fib_table_cleanup(void)
+{
+	int i;
+
+	for (i = RT_TABLE_MIN; i <= RT_TABLE_MAX; ++i)
+		dn_fib_del_tree(i);
+
+	return;
+}