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synced 2024-08-22 00:40:03 +00:00
![Arnd Bergmann](/assets/img/avatar_default.png)
A recent change to the dst_output handling caused a new warning
when the call to NF_HOOK() is the only used of a local variable
passed as 'dev', and CONFIG_NETFILTER is disabled:
net/ipv6/ip6_output.c: In function 'ip6_output':
net/ipv6/ip6_output.c:135:21: warning: unused variable 'dev' [-Wunused-variable]
The reason for this is that the NF_HOOK macro in this case does
not reference the variable at all, and the call to dev_net(dev)
got removed from the ip6_output function. To avoid that warning now
and in the future, this changes the macro into an equivalent
inline function, which tells the compiler that the variable is
passed correctly but still unused.
The dn_forward function apparently had the same problem in
the past and added a local workaround that no longer works
with the inline function. In order to avoid a regression, we
have to also remove the #ifdef from decnet in the same patch.
Fixes: ede2059dba
("dst: Pass net into dst->output")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
420 lines
12 KiB
C
420 lines
12 KiB
C
#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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int thresh;
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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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struct list_head *hook_list;
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int (*okfn)(struct net *, struct sock *, struct sk_buff *);
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};
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static inline void nf_hook_state_init(struct nf_hook_state *p,
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struct list_head *hook_list,
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unsigned int hook,
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int thresh, 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->thresh = thresh;
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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->hook_list = hook_list;
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p->okfn = okfn;
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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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struct list_head list;
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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_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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int nf_register_hook(struct nf_hook_ops *reg);
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void nf_unregister_hook(struct nf_hook_ops *reg);
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int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n);
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void nf_unregister_hooks(struct nf_hook_ops *reg, 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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static inline bool nf_hook_list_active(struct list_head *hook_list,
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u_int8_t pf, unsigned int hook)
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{
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if (__builtin_constant_p(pf) &&
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__builtin_constant_p(hook))
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return static_key_false(&nf_hooks_needed[pf][hook]);
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return !list_empty(hook_list);
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}
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#else
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static inline bool nf_hook_list_active(struct list_head *hook_list,
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u_int8_t pf, unsigned int hook)
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{
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return !list_empty(hook_list);
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}
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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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/**
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* nf_hook_thresh - 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_thresh(u_int8_t pf, unsigned int hook,
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struct net *net,
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struct sock *sk,
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struct sk_buff *skb,
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struct net_device *indev,
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struct net_device *outdev,
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int (*okfn)(struct net *, struct sock *, struct sk_buff *),
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int thresh)
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{
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struct list_head *hook_list = &net->nf.hooks[pf][hook];
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if (nf_hook_list_active(hook_list, pf, hook)) {
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struct nf_hook_state state;
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nf_hook_state_init(&state, hook_list, hook, thresh,
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pf, indev, outdev, sk, net, okfn);
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return nf_hook_slow(skb, &state);
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}
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return 1;
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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 nf_hook_thresh(pf, hook, net, sk, skb, indev, outdev, okfn, INT_MIN);
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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_THRESH(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
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struct sk_buff *skb, struct net_device *in,
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struct net_device *out,
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int (*okfn)(struct net *, struct sock *, struct sk_buff *),
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int thresh)
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{
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int ret = nf_hook_thresh(pf, hook, net, sk, skb, in, out, okfn, thresh);
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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 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_thresh(pf, hook, net, sk, skb, in, out, okfn, INT_MIN)) == 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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return NF_HOOK_THRESH(pf, hook, net, sk, skb, in, out, okfn, INT_MIN);
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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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struct nf_afinfo {
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unsigned short family;
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__sum16 (*checksum)(struct sk_buff *skb, unsigned int hook,
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unsigned int dataoff, u_int8_t protocol);
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__sum16 (*checksum_partial)(struct sk_buff *skb,
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unsigned int hook,
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unsigned int dataoff,
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unsigned int len,
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u_int8_t protocol);
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int (*route)(struct net *net, struct dst_entry **dst,
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struct flowi *fl, bool strict);
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void (*saveroute)(const struct sk_buff *skb,
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struct nf_queue_entry *entry);
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int (*reroute)(struct net *net, struct sk_buff *skb,
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const struct nf_queue_entry *entry);
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int route_key_size;
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};
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extern const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO];
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static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family)
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{
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return rcu_dereference(nf_afinfo[family]);
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}
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static inline __sum16
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nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
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u_int8_t protocol, unsigned short family)
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{
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const struct nf_afinfo *afinfo;
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__sum16 csum = 0;
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rcu_read_lock();
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afinfo = nf_get_afinfo(family);
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if (afinfo)
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csum = afinfo->checksum(skb, hook, dataoff, protocol);
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rcu_read_unlock();
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return csum;
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}
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static inline __sum16
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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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{
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const struct nf_afinfo *afinfo;
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__sum16 csum = 0;
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rcu_read_lock();
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afinfo = nf_get_afinfo(family);
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if (afinfo)
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csum = afinfo->checksum_partial(skb, hook, dataoff, len,
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protocol);
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rcu_read_unlock();
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return csum;
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}
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int nf_register_afinfo(const struct nf_afinfo *afinfo);
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void nf_unregister_afinfo(const struct nf_afinfo *afinfo);
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#include <net/flow.h>
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extern void (*nf_nat_decode_session_hook)(struct sk_buff *, 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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#ifdef CONFIG_NF_NAT_NEEDED
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void (*decodefn)(struct sk_buff *, struct flowi *);
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rcu_read_lock();
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decodefn = rcu_dereference(nf_nat_decode_session_hook);
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if (decodefn)
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decodefn(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 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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extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;
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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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#endif
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struct nf_conn;
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enum ip_conntrack_info;
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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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