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kernel-fxtec-pro1x/include/linux/netfilter.h
Toke Høiland-Jørgensen b60a60405f netfilter: Add nf_ct_get_tuple_skb global lookup function 
This adds a global netfilter function to extract a conntrack tuple from an
skb. The function uses a new function added to nf_ct_hook, which will try
to get the tuple from skb->_nfct, and do a full lookup if that fails. This
makes it possible to use the lookup function before the skb has passed
through the conntrack init hooks (e.g., in an ingress qdisc). The tuple is
copied to the caller to avoid issues with reference counting.

The function returns false if conntrack is not loaded, allowing it to be
used without incurring a module dependency on conntrack. This is used by
the NAT mode in sch_cake.

Cc: netfilter-devel@vger.kernel.org
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-10 20:06:34 -07:00

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/* 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;
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;
}
static inline void
NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
struct list_head *head, struct net_device *in, struct net_device *out,
int (*okfn)(struct net *, struct sock *, struct sk_buff *))
{
struct sk_buff *skb, *next;
struct list_head sublist;
INIT_LIST_HEAD(&sublist);
list_for_each_entry_safe(skb, next, head, list) {
list_del(&skb->list);
if (nf_hook(pf, hook, net, sk, skb, in, out, okfn) == 1)
list_add_tail(&skb->list, &sublist);
}
/* Put passed packets back on main list */
list_splice(&sublist, head);
}
/* 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;
__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);
#include <net/flow.h>
struct nf_conn;
enum nf_nat_manip_type;
struct nlattr;
enum ip_conntrack_dir;
struct nf_nat_hook {
int (*parse_nat_setup)(struct nf_conn *ct, enum nf_nat_manip_type manip,
const struct nlattr *attr);
void (*decode_session)(struct sk_buff *skb, struct flowi *fl);
unsigned int (*manip_pkt)(struct sk_buff *skb, struct nf_conn *ct,
enum nf_nat_manip_type mtype,
enum ip_conntrack_dir dir);
};
extern struct nf_nat_hook __rcu *nf_nat_hook;
static inline void
nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
{
#ifdef CONFIG_NF_NAT_NEEDED
struct nf_nat_hook *nat_hook;
rcu_read_lock();
nat_hook = rcu_dereference(nf_nat_hook);
if (nat_hook && nat_hook->decode_session)
nat_hook->decode_session(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 void
NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
struct list_head *head, struct net_device *in, struct net_device *out,
int (*okfn)(struct net *, struct sock *, struct sk_buff *))
{
/* nothing to do */
}
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 *);
struct nf_conntrack_tuple;
bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
const struct sk_buff *skb);
#else
static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
struct nf_conntrack_tuple;
static inline bool nf_ct_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple,
const struct sk_buff *skb)
{
return false;
}
#endif
struct nf_conn;
enum ip_conntrack_info;
struct nf_ct_hook {
int (*update)(struct net *net, struct sk_buff *skb);
void (*destroy)(struct nf_conntrack *);
bool (*get_tuple_skb)(struct nf_conntrack_tuple *,
const struct sk_buff *);
};
extern struct nf_ct_hook __rcu *nf_ct_hook;
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*/
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