nagai/kernel
3
0
Fork 0
forked from mirrors/linux
Code Pull requests Activity
kernel/include/linux/netfilter.h
Pablo Neira Ayuso ce388f452f netfilter: move reroute indirection to struct nf_ipv6_ops 
We cannot make a direct call to nf_ip6_reroute() because that would result
in autoloading the 'ipv6' module because of symbol dependencies.
Therefore, define reroute indirection in nf_ipv6_ops where this really
belongs to.

For IPv4, we can indeed make a direct function call, which is faster,
given IPv4 is built-in in the networking code by default. Still,
CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline
stub for IPv4 in such case.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08 18:10:53 +01:00

426 lines
12 KiB
C
Raw Blame History

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