1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* linux/net/inet/arp.h */ 3 #ifndef _ARP_H 4 #define _ARP_H 5 6 #include <linux/if_arp.h> 7 #include <linux/hash.h> 8 #include <net/neighbour.h> 9 10 11 extern struct neigh_table arp_tbl; 12 13 static inline u32 arp_hashfn(const void *pkey, const struct net_device *dev, u32 *hash_rnd) 14 { 15 u32 key = *(const u32 *)pkey; 16 u32 val = key ^ hash32_ptr(dev); 17 18 return val * hash_rnd[0]; 19 } 20 21 #ifdef CONFIG_INET 22 static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key) 23 { 24 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) 25 key = INADDR_ANY; 26 27 return ___neigh_lookup_noref(&arp_tbl, neigh_key_eq32, arp_hashfn, &key, dev); 28 } 29 #else 30 static inline 31 struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key) 32 { 33 return NULL; 34 } 35 #endif 36 37 static inline struct neighbour *__ipv4_neigh_lookup(struct net_device *dev, u32 key) 38 { 39 struct neighbour *n; 40 41 rcu_read_lock_bh(); 42 n = __ipv4_neigh_lookup_noref(dev, key); 43 if (n && !refcount_inc_not_zero(&n->refcnt)) 44 n = NULL; 45 rcu_read_unlock_bh(); 46 47 return n; 48 } 49 50 static inline void __ipv4_confirm_neigh(struct net_device *dev, u32 key) 51 { 52 struct neighbour *n; 53 54 rcu_read_lock_bh(); 55 n = __ipv4_neigh_lookup_noref(dev, key); 56 if (n) { 57 unsigned long now = jiffies; 58 59 /* avoid dirtying neighbour */ 60 if (n->confirmed != now) 61 n->confirmed = now; 62 } 63 rcu_read_unlock_bh(); 64 } 65 66 void arp_init(void); 67 int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg); 68 void arp_send(int type, int ptype, __be32 dest_ip, 69 struct net_device *dev, __be32 src_ip, 70 const unsigned char *dest_hw, 71 const unsigned char *src_hw, const unsigned char *th); 72 int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir); 73 void arp_ifdown(struct net_device *dev); 74 75 struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, 76 struct net_device *dev, __be32 src_ip, 77 const unsigned char *dest_hw, 78 const unsigned char *src_hw, 79 const unsigned char *target_hw); 80 void arp_xmit(struct sk_buff *skb); 81 82 #endif /* _ARP_H */ 83