ddd4aa424b
Validity of the cached PMTU information is indicated by it's expiration value being non-zero, just as per dst->expires. The scheme we will use is that we will remember the pre-ICMP value held in the metrics or route entry, and then at expiration time we will restore that value. In this way PMTU expiration does not kill off the cached route as is done currently. Redirect information is permanent, or at least until another redirect is received. Signed-off-by: David S. Miller <davem@davemloft.net>
115 lines
2.9 KiB
C
115 lines
2.9 KiB
C
/*
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* INETPEER - A storage for permanent information about peers
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*
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* Authors: Andrey V. Savochkin <saw@msu.ru>
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*/
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#ifndef _NET_INETPEER_H
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#define _NET_INETPEER_H
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/jiffies.h>
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#include <linux/spinlock.h>
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#include <linux/rtnetlink.h>
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#include <net/ipv6.h>
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#include <asm/atomic.h>
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struct inetpeer_addr_base {
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union {
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__be32 a4;
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__be32 a6[4];
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};
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};
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struct inetpeer_addr {
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struct inetpeer_addr_base addr;
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__u16 family;
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};
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struct inet_peer {
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/* group together avl_left,avl_right,v4daddr to speedup lookups */
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struct inet_peer __rcu *avl_left, *avl_right;
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struct inetpeer_addr daddr;
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__u32 avl_height;
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struct list_head unused;
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__u32 dtime; /* the time of last use of not
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* referenced entries */
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atomic_t refcnt;
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/*
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* Once inet_peer is queued for deletion (refcnt == -1), following fields
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* are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp, metrics
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* We can share memory with rcu_head to help keep inet_peer small.
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*/
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union {
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struct {
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atomic_t rid; /* Frag reception counter */
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atomic_t ip_id_count; /* IP ID for the next packet */
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__u32 tcp_ts;
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__u32 tcp_ts_stamp;
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u32 metrics[RTAX_MAX];
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u32 rate_tokens; /* rate limiting for ICMP */
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unsigned long rate_last;
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unsigned long pmtu_expires;
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u32 pmtu_orig;
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u32 pmtu_learned;
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struct inetpeer_addr_base redirect_learned;
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};
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struct rcu_head rcu;
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};
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};
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void inet_initpeers(void) __init;
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#define INETPEER_METRICS_NEW (~(u32) 0)
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static inline bool inet_metrics_new(const struct inet_peer *p)
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{
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return p->metrics[RTAX_LOCK-1] == INETPEER_METRICS_NEW;
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}
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/* can be called with or without local BH being disabled */
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struct inet_peer *inet_getpeer(struct inetpeer_addr *daddr, int create);
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static inline struct inet_peer *inet_getpeer_v4(__be32 v4daddr, int create)
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{
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struct inetpeer_addr daddr;
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daddr.addr.a4 = v4daddr;
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daddr.family = AF_INET;
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return inet_getpeer(&daddr, create);
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}
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static inline struct inet_peer *inet_getpeer_v6(struct in6_addr *v6daddr, int create)
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{
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struct inetpeer_addr daddr;
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ipv6_addr_copy((struct in6_addr *)daddr.addr.a6, v6daddr);
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daddr.family = AF_INET6;
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return inet_getpeer(&daddr, create);
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}
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/* can be called from BH context or outside */
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extern void inet_putpeer(struct inet_peer *p);
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extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
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/*
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* temporary check to make sure we dont access rid, ip_id_count, tcp_ts,
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* tcp_ts_stamp if no refcount is taken on inet_peer
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*/
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static inline void inet_peer_refcheck(const struct inet_peer *p)
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{
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WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0);
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}
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/* can be called with or without local BH being disabled */
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static inline __u16 inet_getid(struct inet_peer *p, int more)
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{
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more++;
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inet_peer_refcheck(p);
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return atomic_add_return(more, &p->ip_id_count) - more;
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}
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#endif /* _NET_INETPEER_H */
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