| /* |
| * net/dst.h Protocol independent destination cache definitions. |
| * |
| * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| * |
| */ |
| |
| #ifndef _NET_DST_H |
| #define _NET_DST_H |
| |
| #include <net/dst_ops.h> |
| #include <linux/netdevice.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/rcupdate.h> |
| #include <linux/jiffies.h> |
| #include <net/neighbour.h> |
| #include <asm/processor.h> |
| |
| /* |
| * 0 - no debugging messages |
| * 1 - rare events and bugs (default) |
| * 2 - trace mode. |
| */ |
| #define RT_CACHE_DEBUG 0 |
| |
| #define DST_GC_MIN (HZ/10) |
| #define DST_GC_INC (HZ/2) |
| #define DST_GC_MAX (120*HZ) |
| |
| /* Each dst_entry has reference count and sits in some parent list(s). |
| * When it is removed from parent list, it is "freed" (dst_free). |
| * After this it enters dead state (dst->obsolete > 0) and if its refcnt |
| * is zero, it can be destroyed immediately, otherwise it is added |
| * to gc list and garbage collector periodically checks the refcnt. |
| */ |
| |
| struct sk_buff; |
| |
| struct dst_entry { |
| struct rcu_head rcu_head; |
| struct dst_entry *child; |
| struct net_device *dev; |
| short error; |
| short obsolete; |
| int flags; |
| #define DST_HOST 0x0001 |
| #define DST_NOXFRM 0x0002 |
| #define DST_NOPOLICY 0x0004 |
| #define DST_NOHASH 0x0008 |
| #define DST_NOCACHE 0x0010 |
| unsigned long expires; |
| |
| unsigned short header_len; /* more space at head required */ |
| unsigned short trailer_len; /* space to reserve at tail */ |
| |
| unsigned int rate_tokens; |
| unsigned long rate_last; /* rate limiting for ICMP */ |
| |
| struct dst_entry *path; |
| |
| struct neighbour *neighbour; |
| struct hh_cache *hh; |
| #ifdef CONFIG_XFRM |
| struct xfrm_state *xfrm; |
| #else |
| void *__pad1; |
| #endif |
| int (*input)(struct sk_buff*); |
| int (*output)(struct sk_buff*); |
| |
| struct dst_ops *ops; |
| |
| u32 _metrics[RTAX_MAX]; |
| |
| #ifdef CONFIG_IP_ROUTE_CLASSID |
| __u32 tclassid; |
| #else |
| __u32 __pad2; |
| #endif |
| |
| |
| /* |
| * Align __refcnt to a 64 bytes alignment |
| * (L1_CACHE_SIZE would be too much) |
| */ |
| #ifdef CONFIG_64BIT |
| long __pad_to_align_refcnt[1]; |
| #endif |
| /* |
| * __refcnt wants to be on a different cache line from |
| * input/output/ops or performance tanks badly |
| */ |
| atomic_t __refcnt; /* client references */ |
| int __use; |
| unsigned long lastuse; |
| union { |
| struct dst_entry *next; |
| struct rtable __rcu *rt_next; |
| struct rt6_info *rt6_next; |
| struct dn_route __rcu *dn_next; |
| }; |
| }; |
| |
| #ifdef __KERNEL__ |
| |
| static inline u32 |
| dst_metric_raw(const struct dst_entry *dst, const int metric) |
| { |
| return dst->_metrics[metric-1]; |
| } |
| |
| static inline u32 |
| dst_metric(const struct dst_entry *dst, const int metric) |
| { |
| WARN_ON_ONCE(metric == RTAX_HOPLIMIT || |
| metric == RTAX_ADVMSS || |
| metric == RTAX_MTU); |
| return dst_metric_raw(dst, metric); |
| } |
| |
| static inline u32 |
| dst_metric_advmss(const struct dst_entry *dst) |
| { |
| u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS); |
| |
| if (!advmss) |
| advmss = dst->ops->default_advmss(dst); |
| |
| return advmss; |
| } |
| |
| static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val) |
| { |
| dst->_metrics[metric-1] = val; |
| } |
| |
| static inline void dst_import_metrics(struct dst_entry *dst, const u32 *src_metrics) |
| { |
| memcpy(dst->_metrics, src_metrics, RTAX_MAX * sizeof(u32)); |
| } |
| |
| static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src) |
| { |
| dst_import_metrics(dest, src->_metrics); |
| } |
| |
| static inline u32 *dst_metrics_ptr(struct dst_entry *dst) |
| { |
| return dst->_metrics; |
| } |
| |
| static inline u32 |
| dst_feature(const struct dst_entry *dst, u32 feature) |
| { |
| return dst_metric(dst, RTAX_FEATURES) & feature; |
| } |
| |
| static inline u32 dst_mtu(const struct dst_entry *dst) |
| { |
| u32 mtu = dst_metric_raw(dst, RTAX_MTU); |
| |
| if (!mtu) |
| mtu = dst->ops->default_mtu(dst); |
| |
| return mtu; |
| } |
| |
| /* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */ |
| static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric) |
| { |
| return msecs_to_jiffies(dst_metric(dst, metric)); |
| } |
| |
| static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric, |
| unsigned long rtt) |
| { |
| dst_metric_set(dst, metric, jiffies_to_msecs(rtt)); |
| } |
| |
| static inline u32 |
| dst_allfrag(const struct dst_entry *dst) |
| { |
| int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG); |
| /* Yes, _exactly_. This is paranoia. */ |
| barrier(); |
| return ret; |
| } |
| |
| static inline int |
| dst_metric_locked(const struct dst_entry *dst, int metric) |
| { |
| return dst_metric(dst, RTAX_LOCK) & (1<<metric); |
| } |
| |
| static inline void dst_hold(struct dst_entry * dst) |
| { |
| /* |
| * If your kernel compilation stops here, please check |
| * __pad_to_align_refcnt declaration in struct dst_entry |
| */ |
| BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63); |
| atomic_inc(&dst->__refcnt); |
| } |
| |
| static inline void dst_use(struct dst_entry *dst, unsigned long time) |
| { |
| dst_hold(dst); |
| dst->__use++; |
| dst->lastuse = time; |
| } |
| |
| static inline void dst_use_noref(struct dst_entry *dst, unsigned long time) |
| { |
| dst->__use++; |
| dst->lastuse = time; |
| } |
| |
| static inline |
| struct dst_entry * dst_clone(struct dst_entry * dst) |
| { |
| if (dst) |
| atomic_inc(&dst->__refcnt); |
| return dst; |
| } |
| |
| extern void dst_release(struct dst_entry *dst); |
| |
| static inline void refdst_drop(unsigned long refdst) |
| { |
| if (!(refdst & SKB_DST_NOREF)) |
| dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK)); |
| } |
| |
| /** |
| * skb_dst_drop - drops skb dst |
| * @skb: buffer |
| * |
| * Drops dst reference count if a reference was taken. |
| */ |
| static inline void skb_dst_drop(struct sk_buff *skb) |
| { |
| if (skb->_skb_refdst) { |
| refdst_drop(skb->_skb_refdst); |
| skb->_skb_refdst = 0UL; |
| } |
| } |
| |
| static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb) |
| { |
| nskb->_skb_refdst = oskb->_skb_refdst; |
| if (!(nskb->_skb_refdst & SKB_DST_NOREF)) |
| dst_clone(skb_dst(nskb)); |
| } |
| |
| /** |
| * skb_dst_force - makes sure skb dst is refcounted |
| * @skb: buffer |
| * |
| * If dst is not yet refcounted, let's do it |
| */ |
| static inline void skb_dst_force(struct sk_buff *skb) |
| { |
| if (skb_dst_is_noref(skb)) { |
| WARN_ON(!rcu_read_lock_held()); |
| skb->_skb_refdst &= ~SKB_DST_NOREF; |
| dst_clone(skb_dst(skb)); |
| } |
| } |
| |
| |
| /** |
| * __skb_tunnel_rx - prepare skb for rx reinsert |
| * @skb: buffer |
| * @dev: tunnel device |
| * |
| * After decapsulation, packet is going to re-enter (netif_rx()) our stack, |
| * so make some cleanups. (no accounting done) |
| */ |
| static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev) |
| { |
| skb->dev = dev; |
| skb->rxhash = 0; |
| skb_set_queue_mapping(skb, 0); |
| skb_dst_drop(skb); |
| nf_reset(skb); |
| } |
| |
| /** |
| * skb_tunnel_rx - prepare skb for rx reinsert |
| * @skb: buffer |
| * @dev: tunnel device |
| * |
| * After decapsulation, packet is going to re-enter (netif_rx()) our stack, |
| * so make some cleanups, and perform accounting. |
| * Note: this accounting is not SMP safe. |
| */ |
| static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev) |
| { |
| /* TODO : stats should be SMP safe */ |
| dev->stats.rx_packets++; |
| dev->stats.rx_bytes += skb->len; |
| __skb_tunnel_rx(skb, dev); |
| } |
| |
| /* Children define the path of the packet through the |
| * Linux networking. Thus, destinations are stackable. |
| */ |
| |
| static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb) |
| { |
| struct dst_entry *child = skb_dst(skb)->child; |
| |
| skb_dst_drop(skb); |
| return child; |
| } |
| |
| extern int dst_discard(struct sk_buff *skb); |
| extern void * dst_alloc(struct dst_ops * ops); |
| extern void __dst_free(struct dst_entry * dst); |
| extern struct dst_entry *dst_destroy(struct dst_entry * dst); |
| |
| static inline void dst_free(struct dst_entry * dst) |
| { |
| if (dst->obsolete > 1) |
| return; |
| if (!atomic_read(&dst->__refcnt)) { |
| dst = dst_destroy(dst); |
| if (!dst) |
| return; |
| } |
| __dst_free(dst); |
| } |
| |
| static inline void dst_rcu_free(struct rcu_head *head) |
| { |
| struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head); |
| dst_free(dst); |
| } |
| |
| static inline void dst_confirm(struct dst_entry *dst) |
| { |
| if (dst) |
| neigh_confirm(dst->neighbour); |
| } |
| |
| static inline void dst_link_failure(struct sk_buff *skb) |
| { |
| struct dst_entry *dst = skb_dst(skb); |
| if (dst && dst->ops && dst->ops->link_failure) |
| dst->ops->link_failure(skb); |
| } |
| |
| static inline void dst_set_expires(struct dst_entry *dst, int timeout) |
| { |
| unsigned long expires = jiffies + timeout; |
| |
| if (expires == 0) |
| expires = 1; |
| |
| if (dst->expires == 0 || time_before(expires, dst->expires)) |
| dst->expires = expires; |
| } |
| |
| /* Output packet to network from transport. */ |
| static inline int dst_output(struct sk_buff *skb) |
| { |
| return skb_dst(skb)->output(skb); |
| } |
| |
| /* Input packet from network to transport. */ |
| static inline int dst_input(struct sk_buff *skb) |
| { |
| return skb_dst(skb)->input(skb); |
| } |
| |
| static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie) |
| { |
| if (dst->obsolete) |
| dst = dst->ops->check(dst, cookie); |
| return dst; |
| } |
| |
| extern void dst_init(void); |
| |
| /* Flags for xfrm_lookup flags argument. */ |
| enum { |
| XFRM_LOOKUP_WAIT = 1 << 0, |
| XFRM_LOOKUP_ICMP = 1 << 1, |
| }; |
| |
| struct flowi; |
| #ifndef CONFIG_XFRM |
| static inline int xfrm_lookup(struct net *net, struct dst_entry **dst_p, |
| struct flowi *fl, struct sock *sk, int flags) |
| { |
| return 0; |
| } |
| static inline int __xfrm_lookup(struct net *net, struct dst_entry **dst_p, |
| struct flowi *fl, struct sock *sk, int flags) |
| { |
| return 0; |
| } |
| #else |
| extern int xfrm_lookup(struct net *net, struct dst_entry **dst_p, |
| struct flowi *fl, struct sock *sk, int flags); |
| extern int __xfrm_lookup(struct net *net, struct dst_entry **dst_p, |
| struct flowi *fl, struct sock *sk, int flags); |
| #endif |
| #endif |
| |
| #endif /* _NET_DST_H */ |