382 строки
10 KiB
C
382 строки
10 KiB
C
#ifndef __LINUX_NETFILTER_H
|
|
#define __LINUX_NETFILTER_H
|
|
|
|
#ifdef __KERNEL__
|
|
#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>
|
|
#endif
|
|
#include <linux/types.h>
|
|
#include <linux/compiler.h>
|
|
#include <linux/sysctl.h>
|
|
|
|
/* Responses from hook functions. */
|
|
#define NF_DROP 0
|
|
#define NF_ACCEPT 1
|
|
#define NF_STOLEN 2
|
|
#define NF_QUEUE 3
|
|
#define NF_REPEAT 4
|
|
#define NF_STOP 5
|
|
#define NF_MAX_VERDICT NF_STOP
|
|
|
|
/* we overload the higher bits for encoding auxiliary data such as the queue
|
|
* number or errno values. Not nice, but better than additional function
|
|
* arguments. */
|
|
#define NF_VERDICT_MASK 0x000000ff
|
|
|
|
/* extra verdict flags have mask 0x0000ff00 */
|
|
#define NF_VERDICT_FLAG_QUEUE_BYPASS 0x00008000
|
|
|
|
/* queue number (NF_QUEUE) or errno (NF_DROP) */
|
|
#define NF_VERDICT_QMASK 0xffff0000
|
|
#define NF_VERDICT_QBITS 16
|
|
|
|
#define NF_QUEUE_NR(x) ((((x) << 16) & NF_VERDICT_QMASK) | NF_QUEUE)
|
|
|
|
#define NF_DROP_ERR(x) (((-x) << 16) | NF_DROP)
|
|
|
|
/* only for userspace compatibility */
|
|
#ifndef __KERNEL__
|
|
/* Generic cache responses from hook functions.
|
|
<= 0x2000 is used for protocol-flags. */
|
|
#define NFC_UNKNOWN 0x4000
|
|
#define NFC_ALTERED 0x8000
|
|
|
|
/* NF_VERDICT_BITS should be 8 now, but userspace might break if this changes */
|
|
#define NF_VERDICT_BITS 16
|
|
#endif
|
|
|
|
enum nf_inet_hooks {
|
|
NF_INET_PRE_ROUTING,
|
|
NF_INET_LOCAL_IN,
|
|
NF_INET_FORWARD,
|
|
NF_INET_LOCAL_OUT,
|
|
NF_INET_POST_ROUTING,
|
|
NF_INET_NUMHOOKS
|
|
};
|
|
|
|
enum {
|
|
NFPROTO_UNSPEC = 0,
|
|
NFPROTO_IPV4 = 2,
|
|
NFPROTO_ARP = 3,
|
|
NFPROTO_BRIDGE = 7,
|
|
NFPROTO_IPV6 = 10,
|
|
NFPROTO_DECNET = 12,
|
|
NFPROTO_NUMPROTO,
|
|
};
|
|
|
|
union nf_inet_addr {
|
|
__u32 all[4];
|
|
__be32 ip;
|
|
__be32 ip6[4];
|
|
struct in_addr in;
|
|
struct in6_addr in6;
|
|
};
|
|
|
|
#ifdef __KERNEL__
|
|
#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];
|
|
}
|
|
|
|
extern void netfilter_init(void);
|
|
|
|
/* Largest hook number + 1 */
|
|
#define NF_MAX_HOOKS 8
|
|
|
|
struct sk_buff;
|
|
|
|
typedef unsigned int nf_hookfn(unsigned int hooknum,
|
|
struct sk_buff *skb,
|
|
const struct net_device *in,
|
|
const struct net_device *out,
|
|
int (*okfn)(struct sk_buff *));
|
|
|
|
struct nf_hook_ops {
|
|
struct list_head list;
|
|
|
|
/* User fills in from here down. */
|
|
nf_hookfn *hook;
|
|
struct module *owner;
|
|
u_int8_t pf;
|
|
unsigned int hooknum;
|
|
/* Hooks are ordered in ascending priority. */
|
|
int priority;
|
|
};
|
|
|
|
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_hook(struct nf_hook_ops *reg);
|
|
void nf_unregister_hook(struct nf_hook_ops *reg);
|
|
int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n);
|
|
void nf_unregister_hooks(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 CONFIG_SYSCTL
|
|
/* Sysctl registration */
|
|
extern struct ctl_path nf_net_netfilter_sysctl_path[];
|
|
extern struct ctl_path nf_net_ipv4_netfilter_sysctl_path[];
|
|
#endif /* CONFIG_SYSCTL */
|
|
|
|
extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
|
|
|
|
int nf_hook_slow(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
|
|
struct net_device *indev, struct net_device *outdev,
|
|
int (*okfn)(struct sk_buff *), int thresh);
|
|
|
|
/**
|
|
* nf_hook_thresh - 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_thresh(u_int8_t pf, unsigned int hook,
|
|
struct sk_buff *skb,
|
|
struct net_device *indev,
|
|
struct net_device *outdev,
|
|
int (*okfn)(struct sk_buff *), int thresh)
|
|
{
|
|
#ifndef CONFIG_NETFILTER_DEBUG
|
|
if (list_empty(&nf_hooks[pf][hook]))
|
|
return 1;
|
|
#endif
|
|
return nf_hook_slow(pf, hook, skb, indev, outdev, okfn, thresh);
|
|
}
|
|
|
|
static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
|
|
struct net_device *indev, struct net_device *outdev,
|
|
int (*okfn)(struct sk_buff *))
|
|
{
|
|
return nf_hook_thresh(pf, hook, skb, indev, outdev, okfn, INT_MIN);
|
|
}
|
|
|
|
/* 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_THRESH(uint8_t pf, unsigned int hook, struct sk_buff *skb,
|
|
struct net_device *in, struct net_device *out,
|
|
int (*okfn)(struct sk_buff *), int thresh)
|
|
{
|
|
int ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, thresh);
|
|
if (ret == 1)
|
|
ret = okfn(skb);
|
|
return ret;
|
|
}
|
|
|
|
static inline int
|
|
NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sk_buff *skb,
|
|
struct net_device *in, struct net_device *out,
|
|
int (*okfn)(struct sk_buff *), bool cond)
|
|
{
|
|
int ret;
|
|
|
|
if (!cond ||
|
|
((ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, INT_MIN)) == 1))
|
|
ret = okfn(skb);
|
|
return ret;
|
|
}
|
|
|
|
static inline int
|
|
NF_HOOK(uint8_t pf, unsigned int hook, struct sk_buff *skb,
|
|
struct net_device *in, struct net_device *out,
|
|
int (*okfn)(struct sk_buff *))
|
|
{
|
|
return NF_HOOK_THRESH(pf, hook, skb, in, out, okfn, INT_MIN);
|
|
}
|
|
|
|
/* 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. */
|
|
extern int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
|
|
|
|
struct flowi;
|
|
struct nf_queue_entry;
|
|
|
|
struct nf_afinfo {
|
|
unsigned short family;
|
|
__sum16 (*checksum)(struct sk_buff *skb, unsigned int hook,
|
|
unsigned int dataoff, u_int8_t protocol);
|
|
__sum16 (*checksum_partial)(struct sk_buff *skb,
|
|
unsigned int hook,
|
|
unsigned int dataoff,
|
|
unsigned int len,
|
|
u_int8_t protocol);
|
|
int (*route)(struct net *net, struct dst_entry **dst,
|
|
struct flowi *fl, bool strict);
|
|
void (*saveroute)(const struct sk_buff *skb,
|
|
struct nf_queue_entry *entry);
|
|
int (*reroute)(struct sk_buff *skb,
|
|
const struct nf_queue_entry *entry);
|
|
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]);
|
|
}
|
|
|
|
static inline __sum16
|
|
nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
|
|
u_int8_t protocol, unsigned short family)
|
|
{
|
|
const struct nf_afinfo *afinfo;
|
|
__sum16 csum = 0;
|
|
|
|
rcu_read_lock();
|
|
afinfo = nf_get_afinfo(family);
|
|
if (afinfo)
|
|
csum = afinfo->checksum(skb, hook, dataoff, protocol);
|
|
rcu_read_unlock();
|
|
return csum;
|
|
}
|
|
|
|
static inline __sum16
|
|
nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
|
|
unsigned int dataoff, unsigned int len,
|
|
u_int8_t protocol, unsigned short family)
|
|
{
|
|
const struct nf_afinfo *afinfo;
|
|
__sum16 csum = 0;
|
|
|
|
rcu_read_lock();
|
|
afinfo = nf_get_afinfo(family);
|
|
if (afinfo)
|
|
csum = afinfo->checksum_partial(skb, hook, dataoff, len,
|
|
protocol);
|
|
rcu_read_unlock();
|
|
return csum;
|
|
}
|
|
|
|
extern int nf_register_afinfo(const struct nf_afinfo *afinfo);
|
|
extern void nf_unregister_afinfo(const struct nf_afinfo *afinfo);
|
|
|
|
#include <net/flow.h>
|
|
extern void (*ip_nat_decode_session)(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 *);
|
|
|
|
if (family == AF_INET) {
|
|
rcu_read_lock();
|
|
decodefn = rcu_dereference(ip_nat_decode_session);
|
|
if (decodefn)
|
|
decodefn(skb, fl);
|
|
rcu_read_unlock();
|
|
}
|
|
#endif
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
#include <linux/proc_fs.h>
|
|
extern struct proc_dir_entry *proc_net_netfilter;
|
|
#endif
|
|
|
|
#else /* !CONFIG_NETFILTER */
|
|
#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
|
|
#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
|
|
static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
|
|
struct sk_buff *skb,
|
|
struct net_device *indev,
|
|
struct net_device *outdev,
|
|
int (*okfn)(struct sk_buff *), int thresh)
|
|
{
|
|
return okfn(skb);
|
|
}
|
|
static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
|
|
struct net_device *indev, struct net_device *outdev,
|
|
int (*okfn)(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)
|
|
extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *) __rcu;
|
|
extern void nf_ct_attach(struct sk_buff *, 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
|
|
|
|
#endif /*__KERNEL__*/
|
|
#endif /*__LINUX_NETFILTER_H*/
|