1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _NF_QUEUE_H 3 #define _NF_QUEUE_H 4 5 #include <linux/ip.h> 6 #include <linux/ipv6.h> 7 #include <linux/jhash.h> 8 #include <linux/netfilter.h> 9 #include <linux/skbuff.h> 10 11 /* Each queued (to userspace) skbuff has one of these. */ 12 struct nf_queue_entry { 13 struct list_head list; 14 struct sk_buff *skb; 15 unsigned int id; 16 unsigned int hook_index; /* index in hook_entries->hook[] */ 17 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 18 struct net_device *physin; 19 struct net_device *physout; 20 #endif 21 struct nf_hook_state state; 22 u16 size; /* sizeof(entry) + saved route keys */ 23 24 /* extra space to store route keys */ 25 }; 26 27 #define nf_queue_entry_reroute(x) ((void *)x + sizeof(struct nf_queue_entry)) 28 29 /* Packet queuing */ 30 struct nf_queue_handler { 31 int (*outfn)(struct nf_queue_entry *entry, 32 unsigned int queuenum); 33 void (*nf_hook_drop)(struct net *net); 34 }; 35 36 void nf_register_queue_handler(const struct nf_queue_handler *qh); 37 void nf_unregister_queue_handler(void); 38 void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict); 39 40 bool nf_queue_entry_get_refs(struct nf_queue_entry *entry); 41 void nf_queue_entry_free(struct nf_queue_entry *entry); 42 43 static inline void init_hashrandom(u32 *jhash_initval) 44 { 45 while (*jhash_initval == 0) 46 *jhash_initval = prandom_u32(); 47 } 48 49 static inline u32 hash_v4(const struct iphdr *iph, u32 initval) 50 { 51 /* packets in either direction go into same queue */ 52 if ((__force u32)iph->saddr < (__force u32)iph->daddr) 53 return jhash_3words((__force u32)iph->saddr, 54 (__force u32)iph->daddr, iph->protocol, initval); 55 56 return jhash_3words((__force u32)iph->daddr, 57 (__force u32)iph->saddr, iph->protocol, initval); 58 } 59 60 static inline u32 hash_v6(const struct ipv6hdr *ip6h, u32 initval) 61 { 62 u32 a, b, c; 63 64 if ((__force u32)ip6h->saddr.s6_addr32[3] < 65 (__force u32)ip6h->daddr.s6_addr32[3]) { 66 a = (__force u32) ip6h->saddr.s6_addr32[3]; 67 b = (__force u32) ip6h->daddr.s6_addr32[3]; 68 } else { 69 b = (__force u32) ip6h->saddr.s6_addr32[3]; 70 a = (__force u32) ip6h->daddr.s6_addr32[3]; 71 } 72 73 if ((__force u32)ip6h->saddr.s6_addr32[1] < 74 (__force u32)ip6h->daddr.s6_addr32[1]) 75 c = (__force u32) ip6h->saddr.s6_addr32[1]; 76 else 77 c = (__force u32) ip6h->daddr.s6_addr32[1]; 78 79 return jhash_3words(a, b, c, initval); 80 } 81 82 static inline u32 hash_bridge(const struct sk_buff *skb, u32 initval) 83 { 84 struct ipv6hdr *ip6h, _ip6h; 85 struct iphdr *iph, _iph; 86 87 switch (eth_hdr(skb)->h_proto) { 88 case htons(ETH_P_IP): 89 iph = skb_header_pointer(skb, skb_network_offset(skb), 90 sizeof(*iph), &_iph); 91 if (iph) 92 return hash_v4(iph, initval); 93 break; 94 case htons(ETH_P_IPV6): 95 ip6h = skb_header_pointer(skb, skb_network_offset(skb), 96 sizeof(*ip6h), &_ip6h); 97 if (ip6h) 98 return hash_v6(ip6h, initval); 99 break; 100 } 101 102 return 0; 103 } 104 105 static inline u32 106 nfqueue_hash(const struct sk_buff *skb, u16 queue, u16 queues_total, u8 family, 107 u32 initval) 108 { 109 switch (family) { 110 case NFPROTO_IPV4: 111 queue += reciprocal_scale(hash_v4(ip_hdr(skb), initval), 112 queues_total); 113 break; 114 case NFPROTO_IPV6: 115 queue += reciprocal_scale(hash_v6(ipv6_hdr(skb), initval), 116 queues_total); 117 break; 118 case NFPROTO_BRIDGE: 119 queue += reciprocal_scale(hash_bridge(skb, initval), 120 queues_total); 121 break; 122 } 123 124 return queue; 125 } 126 127 int nf_queue(struct sk_buff *skb, struct nf_hook_state *state, 128 unsigned int index, unsigned int verdict); 129 130 #endif /* _NF_QUEUE_H */ 131