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linux/include/net/fib_rules.h
David S. Miller 7a9bc9b81a ipv4: Elide fib_validate_source() completely when possible.
If rpfilter is off (or the SKB has an IPSEC path) and there are not
tclassid users, we don't have to do anything at all when
fib_validate_source() is invoked besides setting the itag to zero.

We monitor tclassid uses with a counter (modified only under RTNL and
marked __read_mostly) and we protect the fib_validate_source() real
work with a test against this counter and whether rpfilter is to be
done.

Having a way to know whether we need no tclassid processing or not
also opens the door for future optimized rpfilter algorithms that do
not perform full FIB lookups.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-29 01:36:36 -07:00

121 lines
3.0 KiB
C

#ifndef __NET_FIB_RULES_H
#define __NET_FIB_RULES_H
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/fib_rules.h>
#include <net/flow.h>
#include <net/rtnetlink.h>
struct fib_rule {
struct list_head list;
atomic_t refcnt;
int iifindex;
int oifindex;
u32 mark;
u32 mark_mask;
u32 pref;
u32 flags;
u32 table;
u8 action;
u32 target;
struct fib_rule __rcu *ctarget;
char iifname[IFNAMSIZ];
char oifname[IFNAMSIZ];
struct rcu_head rcu;
struct net * fr_net;
};
struct fib_lookup_arg {
void *lookup_ptr;
void *result;
struct fib_rule *rule;
int flags;
#define FIB_LOOKUP_NOREF 1
};
struct fib_rules_ops {
int family;
struct list_head list;
int rule_size;
int addr_size;
int unresolved_rules;
int nr_goto_rules;
int (*action)(struct fib_rule *,
struct flowi *, int,
struct fib_lookup_arg *);
int (*match)(struct fib_rule *,
struct flowi *, int);
int (*configure)(struct fib_rule *,
struct sk_buff *,
struct fib_rule_hdr *,
struct nlattr **);
void (*delete)(struct fib_rule *);
int (*compare)(struct fib_rule *,
struct fib_rule_hdr *,
struct nlattr **);
int (*fill)(struct fib_rule *, struct sk_buff *,
struct fib_rule_hdr *);
u32 (*default_pref)(struct fib_rules_ops *ops);
size_t (*nlmsg_payload)(struct fib_rule *);
/* Called after modifications to the rules set, must flush
* the route cache if one exists. */
void (*flush_cache)(struct fib_rules_ops *ops);
int nlgroup;
const struct nla_policy *policy;
struct list_head rules_list;
struct module *owner;
struct net *fro_net;
struct rcu_head rcu;
};
#define FRA_GENERIC_POLICY \
[FRA_IIFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 }, \
[FRA_OIFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 }, \
[FRA_PRIORITY] = { .type = NLA_U32 }, \
[FRA_FWMARK] = { .type = NLA_U32 }, \
[FRA_FWMASK] = { .type = NLA_U32 }, \
[FRA_TABLE] = { .type = NLA_U32 }, \
[FRA_GOTO] = { .type = NLA_U32 }
static inline void fib_rule_get(struct fib_rule *rule)
{
atomic_inc(&rule->refcnt);
}
static inline void fib_rule_put_rcu(struct rcu_head *head)
{
struct fib_rule *rule = container_of(head, struct fib_rule, rcu);
release_net(rule->fr_net);
kfree(rule);
}
static inline void fib_rule_put(struct fib_rule *rule)
{
if (atomic_dec_and_test(&rule->refcnt))
call_rcu(&rule->rcu, fib_rule_put_rcu);
}
static inline u32 frh_get_table(struct fib_rule_hdr *frh, struct nlattr **nla)
{
if (nla[FRA_TABLE])
return nla_get_u32(nla[FRA_TABLE]);
return frh->table;
}
extern struct fib_rules_ops *fib_rules_register(const struct fib_rules_ops *, struct net *);
extern void fib_rules_unregister(struct fib_rules_ops *);
extern int fib_rules_lookup(struct fib_rules_ops *,
struct flowi *, int flags,
struct fib_lookup_arg *);
extern int fib_default_rule_add(struct fib_rules_ops *,
u32 pref, u32 table,
u32 flags);
extern u32 fib_default_rule_pref(struct fib_rules_ops *ops);
#endif