| #ifndef __LINUX_NETFILTER_H |
| #define __LINUX_NETFILTER_H |
| |
| #ifdef __KERNEL__ |
| #include <linux/init.h> |
| #include <linux/types.h> |
| #include <linux/skbuff.h> |
| #include <linux/net.h> |
| #include <linux/if.h> |
| #include <linux/wait.h> |
| #include <linux/list.h> |
| #endif |
| #include <linux/compiler.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. Not nice, but better than additional function arguments. */ |
| #define NF_VERDICT_MASK 0x0000ffff |
| #define NF_VERDICT_BITS 16 |
| |
| #define NF_VERDICT_QMASK 0xffff0000 |
| #define NF_VERDICT_QBITS 16 |
| |
| #define NF_QUEUE_NR(x) (((x << NF_VERDICT_QBITS) & NF_VERDICT_QMASK) | NF_QUEUE) |
| |
| /* 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 |
| #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 |
| }; |
| |
| union nf_inet_addr { |
| u_int32_t all[4]; |
| __be32 ip; |
| __be32 ip6[4]; |
| }; |
| |
| #ifdef __KERNEL__ |
| #ifdef CONFIG_NETFILTER |
| |
| extern void netfilter_init(void); |
| |
| /* Largest hook number + 1 */ |
| #define NF_MAX_HOOKS 8 |
| |
| struct sk_buff; |
| struct net_device; |
| |
| 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; |
| int pf; |
| int hooknum; |
| /* Hooks are ordered in ascending priority. */ |
| int priority; |
| }; |
| |
| struct nf_sockopt_ops |
| { |
| struct list_head list; |
| |
| int 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); |
| int (*compat_set)(struct sock *sk, int optval, |
| void __user *user, unsigned int len); |
| |
| int get_optmin; |
| int get_optmax; |
| int (*get)(struct sock *sk, int optval, void __user *user, int *len); |
| int (*compat_get)(struct sock *sk, int optval, |
| void __user *user, int *len); |
| |
| /* 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[NPROTO][NF_MAX_HOOKS]; |
| |
| int nf_hook_slow(int 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(int pf, unsigned int hook, |
| struct sk_buff *skb, |
| struct net_device *indev, |
| struct net_device *outdev, |
| int (*okfn)(struct sk_buff *), int thresh, |
| int cond) |
| { |
| if (!cond) |
| return 1; |
| #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(int 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, 1); |
| } |
| |
| /* 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 :) |
| */ |
| |
| /* This is gross, but inline doesn't cut it for avoiding the function |
| call in fast path: gcc doesn't inline (needs value tracking?). --RR */ |
| |
| /* HX: It's slightly less gross now. */ |
| |
| #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \ |
| ({int __ret; \ |
| if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, thresh, 1)) == 1)\ |
| __ret = (okfn)(skb); \ |
| __ret;}) |
| |
| #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) \ |
| ({int __ret; \ |
| if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN, cond)) == 1)\ |
| __ret = (okfn)(skb); \ |
| __ret;}) |
| |
| #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \ |
| NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN) |
| |
| /* Call setsockopt() */ |
| int nf_setsockopt(struct sock *sk, int pf, int optval, char __user *opt, |
| int len); |
| int nf_getsockopt(struct sock *sk, int pf, int optval, char __user *opt, |
| int *len); |
| |
| int compat_nf_setsockopt(struct sock *sk, int pf, int optval, |
| char __user *opt, int len); |
| int compat_nf_getsockopt(struct sock *sk, int pf, int optval, |
| char __user *opt, int *len); |
| |
| /* 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); |
| int (*route)(struct dst_entry **dst, struct flowi *fl); |
| 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 *nf_afinfo[NPROTO]; |
| 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; |
| } |
| |
| 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, int 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(int pf, unsigned int hook, |
| struct sk_buff *skb, |
| struct net_device *indev, |
| struct net_device *outdev, |
| int (*okfn)(struct sk_buff *), int thresh, |
| int cond) |
| { |
| return okfn(skb); |
| } |
| static inline int nf_hook(int 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, int 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 *); |
| extern void nf_ct_attach(struct sk_buff *, struct sk_buff *); |
| extern void (*nf_ct_destroy)(struct nf_conntrack *); |
| #else |
| static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} |
| #endif |
| |
| #endif /*__KERNEL__*/ |
| #endif /*__LINUX_NETFILTER_H*/ |