dn_route.rar_The Other

/* * 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. * Steve Whitehouse : RCU for the route cache * Steve Whitehouse : Preparations for the flow cache * Steve Whitehouse : Prepare for nonlinear skbs */ /****************************************************************************** (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/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 <linux/in_route.h> #include <linux/slab.h> #include <net/sock.h> #include <linux/mm.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/init.h> #include <linux/rtnetlink.h> #include <linux/string.h> #include <linux/netfilter_decnet.h> #include <linux/rcupdate.h> #include <linux/times.h> #include <linux/export.h> #include <asm/errno.h> #include <net/net_namespace.h> #include <net/netlink.h> #include <net/neighbour.h> #include <net/dst.h> #include <net/flow.h> #include <net/fib_rules.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 __rcu *chain; spinlock_t lock; }; extern struct neigh_table dn_neigh_table; static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00}; static const int dn_rt_min_delay = 2 * HZ; static const int dn_rt_max_delay = 10 * HZ; static const int dn_rt_mtu_expires = 10 * 60 * HZ; static unsigned long dn_rt_deadline; static int dn_dst_gc(struct dst_ops *ops); static struct dst_entry *dn_dst_check(struct dst_entry *, __u32); static unsigned int dn_dst_default_advmss(const struct dst_entry *dst); static unsigned int dn_dst_mtu(const struct dst_entry *dst); static void dn_dst_destroy(struct dst_entry *); static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how); static struct dst_entry *dn_dst_negative_advice(struct dst_entry *); static void dn_dst_link_failure(struct sk_buff *); static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb , u32 mtu); static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb); static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst, struct sk_buff *skb, const void *daddr); 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 int dn_rt_hash_mask; static struct timer_list dn_route_timer; static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0); int decnet_dst_gc_interval = 2; static struct dst_ops dn_dst_ops = { .family = PF_DECnet, .protocol = cpu_to_be16(ETH_P_DNA_RT), .gc_thresh = 128, .gc = dn_dst_gc, .check = dn_dst_check, .default_advmss = dn_dst_default_advmss, .mtu = dn_dst_mtu, .cow_metrics = dst_cow_metrics_generic, .destroy = dn_dst_destroy, .ifdown = dn_dst_ifdown, .negative_advice = dn_dst_negative_advice, .link_failure = dn_dst_link_failure, .update_pmtu = dn_dst_update_pmtu, .redirect = dn_dst_redirect, .neigh_lookup = dn_dst_neigh_lookup, }; static void dn_dst_destroy(struct dst_entry *dst) { struct dn_route *rt = (struct dn_route *) dst; if (rt->n) neigh_release(rt->n); dst_destroy_metrics_generic(dst); } static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how) { if (how) { struct dn_route *rt = (struct dn_route *) dst; struct neighbour *n = rt->n; if (n && n->dev == dev) { n->dev = dev_net(dev)->loopback_dev; dev_hold(n->dev); dev_put(dev); } } } static __inline__ unsigned int dn_hash(__le16 src, __le16 dst) { __u16 tmp = (__u16 __force)(src ^ dst); tmp ^= (tmp >> 3); tmp ^= (tmp >> 5); tmp ^= (tmp >> 10); return dn_rt_hash_mask & (unsigned int)tmp; } static inline void dnrt_free(struct dn_route *rt) { call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); } static inline void dnrt_drop(struct dn_route *rt) { dst_release(&rt->dst); call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); } static void dn_dst_check_expire(unsigned long dummy) { int i; struct dn_route *rt; struct dn_route __rcu **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; spin_lock(&dn_rt_hash_table[i].lock); while ((rt = rcu_dereference_protected(*rtp, lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) { if (atomic_read(&rt->dst.__refcnt) || (now - rt->dst.lastuse) < expire) { rtp = &rt->dst.dn_next; continue; } *rtp = rt->dst.dn_next; rt->dst.dn_next = NULL; dnrt_free(rt); } spin_unlock(&dn_rt_hash_table[i].lock); if ((jiffies - now) > 0) break; } mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ); } static int dn_dst_gc(struct dst_ops *ops) { struct dn_route *rt; struct dn_route __rcu **rtp; int i; unsigned long now = jiffies; unsigned long expire = 10 * HZ; for (i = 0; i <= dn_rt_hash_mask; i++) { spi