470 lines
13 KiB
C
470 lines
13 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __LINUX_NETFILTER_H
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#define __LINUX_NETFILTER_H
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#include <linux/init.h>
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#include <linux/skbuff.h>
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#include <linux/net.h>
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#include <linux/if.h>
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#include <linux/in.h>
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#include <linux/in6.h>
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#include <linux/wait.h>
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#include <linux/list.h>
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#include <linux/static_key.h>
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#include <linux/netfilter_defs.h>
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#include <linux/netdevice.h>
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#include <net/net_namespace.h>
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#ifdef CONFIG_NETFILTER
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static inline int NF_DROP_GETERR(int verdict)
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{
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return -(verdict >> NF_VERDICT_QBITS);
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}
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static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1,
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const union nf_inet_addr *a2)
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{
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return a1->all[0] == a2->all[0] &&
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a1->all[1] == a2->all[1] &&
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a1->all[2] == a2->all[2] &&
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a1->all[3] == a2->all[3];
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}
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static inline void nf_inet_addr_mask(const union nf_inet_addr *a1,
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union nf_inet_addr *result,
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const union nf_inet_addr *mask)
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{
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result->all[0] = a1->all[0] & mask->all[0];
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result->all[1] = a1->all[1] & mask->all[1];
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result->all[2] = a1->all[2] & mask->all[2];
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result->all[3] = a1->all[3] & mask->all[3];
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}
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int netfilter_init(void);
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struct sk_buff;
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struct nf_hook_ops;
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struct sock;
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struct nf_hook_state {
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unsigned int hook;
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u_int8_t pf;
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struct net_device *in;
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struct net_device *out;
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struct sock *sk;
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struct net *net;
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int (*okfn)(struct net *, struct sock *, struct sk_buff *);
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};
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typedef unsigned int nf_hookfn(void *priv,
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struct sk_buff *skb,
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const struct nf_hook_state *state);
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struct nf_hook_ops {
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/* User fills in from here down. */
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nf_hookfn *hook;
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struct net_device *dev;
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void *priv;
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u_int8_t pf;
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unsigned int hooknum;
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/* Hooks are ordered in ascending priority. */
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int priority;
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};
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struct nf_hook_entry {
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nf_hookfn *hook;
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void *priv;
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};
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struct nf_hook_entries_rcu_head {
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struct rcu_head head;
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void *allocation;
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};
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struct nf_hook_entries {
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u16 num_hook_entries;
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/* padding */
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struct nf_hook_entry hooks[];
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/* trailer: pointers to original orig_ops of each hook,
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* followed by rcu_head and scratch space used for freeing
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* the structure via call_rcu.
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*
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* This is not part of struct nf_hook_entry since its only
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* needed in slow path (hook register/unregister):
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* const struct nf_hook_ops *orig_ops[]
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*
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* For the same reason, we store this at end -- its
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* only needed when a hook is deleted, not during
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* packet path processing:
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* struct nf_hook_entries_rcu_head head
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*/
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};
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static inline struct nf_hook_ops **nf_hook_entries_get_hook_ops(const struct nf_hook_entries *e)
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{
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unsigned int n = e->num_hook_entries;
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const void *hook_end;
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hook_end = &e->hooks[n]; /* this is *past* ->hooks[]! */
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return (struct nf_hook_ops **)hook_end;
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}
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static inline int
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nf_hook_entry_hookfn(const struct nf_hook_entry *entry, struct sk_buff *skb,
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struct nf_hook_state *state)
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{
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return entry->hook(entry->priv, skb, state);
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}
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static inline void nf_hook_state_init(struct nf_hook_state *p,
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unsigned int hook,
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u_int8_t pf,
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struct net_device *indev,
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struct net_device *outdev,
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struct sock *sk,
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struct net *net,
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int (*okfn)(struct net *, struct sock *, struct sk_buff *))
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{
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p->hook = hook;
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p->pf = pf;
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p->in = indev;
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p->out = outdev;
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p->sk = sk;
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p->net = net;
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p->okfn = okfn;
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}
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struct nf_sockopt_ops {
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struct list_head list;
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u_int8_t pf;
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/* Non-inclusive ranges: use 0/0/NULL to never get called. */
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int set_optmin;
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int set_optmax;
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int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len);
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#ifdef CONFIG_COMPAT
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int (*compat_set)(struct sock *sk, int optval,
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void __user *user, unsigned int len);
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#endif
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int get_optmin;
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int get_optmax;
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int (*get)(struct sock *sk, int optval, void __user *user, int *len);
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#ifdef CONFIG_COMPAT
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int (*compat_get)(struct sock *sk, int optval,
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void __user *user, int *len);
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#endif
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/* Use the module struct to lock set/get code in place */
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struct module *owner;
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};
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/* Function to register/unregister hook points. */
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int nf_register_net_hook(struct net *net, const struct nf_hook_ops *ops);
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void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *ops);
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int nf_register_net_hooks(struct net *net, const struct nf_hook_ops *reg,
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unsigned int n);
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void nf_unregister_net_hooks(struct net *net, const struct nf_hook_ops *reg,
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unsigned int n);
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/* Functions to register get/setsockopt ranges (non-inclusive). You
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need to check permissions yourself! */
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int nf_register_sockopt(struct nf_sockopt_ops *reg);
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void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
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#ifdef HAVE_JUMP_LABEL
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extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
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#endif
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int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state,
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const struct nf_hook_entries *e, unsigned int i);
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/**
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* nf_hook - call a netfilter hook
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*
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* Returns 1 if the hook has allowed the packet to pass. The function
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* okfn must be invoked by the caller in this case. Any other return
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* value indicates the packet has been consumed by the hook.
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*/
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static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
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struct sock *sk, struct sk_buff *skb,
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struct net_device *indev, struct net_device *outdev,
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int (*okfn)(struct net *, struct sock *, struct sk_buff *))
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{
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struct nf_hook_entries *hook_head = NULL;
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int ret = 1;
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#ifdef HAVE_JUMP_LABEL
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if (__builtin_constant_p(pf) &&
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__builtin_constant_p(hook) &&
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!static_key_false(&nf_hooks_needed[pf][hook]))
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return 1;
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#endif
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rcu_read_lock();
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switch (pf) {
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case NFPROTO_IPV4:
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hook_head = rcu_dereference(net->nf.hooks_ipv4[hook]);
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break;
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case NFPROTO_IPV6:
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hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]);
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break;
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case NFPROTO_ARP:
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#ifdef CONFIG_NETFILTER_FAMILY_ARP
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hook_head = rcu_dereference(net->nf.hooks_arp[hook]);
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#endif
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break;
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case NFPROTO_BRIDGE:
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#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
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hook_head = rcu_dereference(net->nf.hooks_bridge[hook]);
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#endif
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break;
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#if IS_ENABLED(CONFIG_DECNET)
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case NFPROTO_DECNET:
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hook_head = rcu_dereference(net->nf.hooks_decnet[hook]);
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break;
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#endif
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default:
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WARN_ON_ONCE(1);
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break;
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}
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if (hook_head) {
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struct nf_hook_state state;
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nf_hook_state_init(&state, hook, pf, indev, outdev,
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sk, net, okfn);
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ret = nf_hook_slow(skb, &state, hook_head, 0);
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}
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rcu_read_unlock();
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return ret;
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}
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/* Activate hook; either okfn or kfree_skb called, unless a hook
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returns NF_STOLEN (in which case, it's up to the hook to deal with
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the consequences).
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Returns -ERRNO if packet dropped. Zero means queued, stolen or
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accepted.
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*/
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/* RR:
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> I don't want nf_hook to return anything because people might forget
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> about async and trust the return value to mean "packet was ok".
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AK:
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Just document it clearly, then you can expect some sense from kernel
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coders :)
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*/
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static inline int
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NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
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struct sk_buff *skb, struct net_device *in, struct net_device *out,
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int (*okfn)(struct net *, struct sock *, struct sk_buff *),
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bool cond)
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{
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int ret;
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if (!cond ||
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((ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn)) == 1))
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ret = okfn(net, sk, skb);
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return ret;
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}
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static inline int
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NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk, struct sk_buff *skb,
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struct net_device *in, struct net_device *out,
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int (*okfn)(struct net *, struct sock *, struct sk_buff *))
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{
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int ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn);
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if (ret == 1)
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ret = okfn(net, sk, skb);
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return ret;
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}
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static inline void
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NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
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struct list_head *head, struct net_device *in, struct net_device *out,
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int (*okfn)(struct net *, struct sock *, struct sk_buff *))
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{
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struct sk_buff *skb, *next;
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struct list_head sublist;
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INIT_LIST_HEAD(&sublist);
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list_for_each_entry_safe(skb, next, head, list) {
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list_del(&skb->list);
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if (nf_hook(pf, hook, net, sk, skb, in, out, okfn) == 1)
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list_add_tail(&skb->list, &sublist);
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}
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/* Put passed packets back on main list */
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list_splice(&sublist, head);
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}
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/* Call setsockopt() */
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int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
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unsigned int len);
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int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
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int *len);
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#ifdef CONFIG_COMPAT
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int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval,
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char __user *opt, unsigned int len);
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int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval,
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char __user *opt, int *len);
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#endif
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/* Call this before modifying an existing packet: ensures it is
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modifiable and linear to the point you care about (writable_len).
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Returns true or false. */
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int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
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struct flowi;
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struct nf_queue_entry;
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__sum16 nf_checksum(struct sk_buff *skb, unsigned int hook,
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unsigned int dataoff, u_int8_t protocol,
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unsigned short family);
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__sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
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unsigned int dataoff, unsigned int len,
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u_int8_t protocol, unsigned short family);
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int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
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bool strict, unsigned short family);
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int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry);
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#include <net/flow.h>
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struct nf_conn;
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enum nf_nat_manip_type;
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struct nlattr;
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enum ip_conntrack_dir;
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struct nf_nat_hook {
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int (*parse_nat_setup)(struct nf_conn *ct, enum nf_nat_manip_type manip,
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const struct nlattr *attr);
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void (*decode_session)(struct sk_buff *skb, struct flowi *fl);
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unsigned int (*manip_pkt)(struct sk_buff *skb, struct nf_conn *ct,
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enum nf_nat_manip_type mtype,
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enum ip_conntrack_dir dir);
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};
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extern struct nf_nat_hook __rcu *nf_nat_hook;
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static inline void
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nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
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{
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#ifdef CONFIG_NF_NAT_NEEDED
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struct nf_nat_hook *nat_hook;
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rcu_read_lock();
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nat_hook = rcu_dereference(nf_nat_hook);
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if (nat_hook && nat_hook->decode_session)
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nat_hook->decode_session(skb, fl);
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rcu_read_unlock();
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#endif
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}
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#else /* !CONFIG_NETFILTER */
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static inline int
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NF_HOOK_COND(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
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struct sk_buff *skb, struct net_device *in, struct net_device *out,
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int (*okfn)(struct net *, struct sock *, struct sk_buff *),
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bool cond)
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{
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return okfn(net, sk, skb);
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}
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static inline int
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NF_HOOK(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
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struct sk_buff *skb, struct net_device *in, struct net_device *out,
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int (*okfn)(struct net *, struct sock *, struct sk_buff *))
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{
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return okfn(net, sk, skb);
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}
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static inline void
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NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
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struct list_head *head, struct net_device *in, struct net_device *out,
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int (*okfn)(struct net *, struct sock *, struct sk_buff *))
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{
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/* nothing to do */
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}
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static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
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struct sock *sk, struct sk_buff *skb,
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struct net_device *indev, struct net_device *outdev,
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int (*okfn)(struct net *, struct sock *, struct sk_buff *))
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{
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return 1;
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}
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struct flowi;
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static inline void
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nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
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{
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}
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#endif /*CONFIG_NETFILTER*/
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#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
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#include <linux/netfilter/nf_conntrack_zones_common.h>
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extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu;
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void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
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struct nf_conntrack_tuple;
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bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
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const struct sk_buff *skb);
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#else
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static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
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struct nf_conntrack_tuple;
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static inline bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
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const struct sk_buff *skb)
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{
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return false;
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}
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#endif
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struct nf_conn;
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enum ip_conntrack_info;
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struct nf_ct_hook {
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int (*update)(struct net *net, struct sk_buff *skb);
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void (*destroy)(struct nf_conntrack *);
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bool (*get_tuple_skb)(struct nf_conntrack_tuple *,
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const struct sk_buff *);
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};
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extern struct nf_ct_hook __rcu *nf_ct_hook;
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struct nlattr;
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struct nfnl_ct_hook {
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struct nf_conn *(*get_ct)(const struct sk_buff *skb,
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enum ip_conntrack_info *ctinfo);
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size_t (*build_size)(const struct nf_conn *ct);
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int (*build)(struct sk_buff *skb, struct nf_conn *ct,
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enum ip_conntrack_info ctinfo,
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u_int16_t ct_attr, u_int16_t ct_info_attr);
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int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
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int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,
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u32 portid, u32 report);
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void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
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enum ip_conntrack_info ctinfo, s32 off);
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};
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extern struct nfnl_ct_hook __rcu *nfnl_ct_hook;
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/**
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* nf_skb_duplicated - TEE target has sent a packet
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*
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* When a xtables target sends a packet, the OUTPUT and POSTROUTING
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* hooks are traversed again, i.e. nft and xtables are invoked recursively.
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*
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* This is used by xtables TEE target to prevent the duplicated skb from
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* being duplicated again.
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*/
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DECLARE_PER_CPU(bool, nf_skb_duplicated);
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#endif /*__LINUX_NETFILTER_H*/
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