diff options
Diffstat (limited to 'include/linux/netfilter.h')
| -rw-r--r-- | include/linux/netfilter.h | 379 |
1 files changed, 379 insertions, 0 deletions
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h new file mode 100644 index 000000000..63560d0a8 --- /dev/null +++ b/include/linux/netfilter.h @@ -0,0 +1,379 @@ +#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 <uapi/linux/netfilter.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); + +/* Largest hook number + 1 */ +#define NF_MAX_HOOKS 8 + +struct sk_buff; + +struct nf_hook_ops; + +struct sock; + +struct nf_hook_state { + unsigned int hook; + int thresh; + u_int8_t pf; + struct net_device *in; + struct net_device *out; + struct sock *sk; + int (*okfn)(struct sock *, struct sk_buff *); +}; + +static inline void nf_hook_state_init(struct nf_hook_state *p, + unsigned int hook, + int thresh, u_int8_t pf, + struct net_device *indev, + struct net_device *outdev, + struct sock *sk, + int (*okfn)(struct sock *, struct sk_buff *)) +{ + p->hook = hook; + p->thresh = thresh; + p->pf = pf; + p->in = indev; + p->out = outdev; + p->sk = sk; + p->okfn = okfn; +} + +typedef unsigned int nf_hookfn(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct nf_hook_state *state); + +struct nf_hook_ops { + struct list_head list; + + /* User fills in from here down. */ + nf_hookfn *hook; + struct module *owner; + void *priv; + 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); + +extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; + +#ifdef HAVE_JUMP_LABEL +extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; + +static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook) +{ + if (__builtin_constant_p(pf) && + __builtin_constant_p(hook)) + return static_key_false(&nf_hooks_needed[pf][hook]); + + return !list_empty(&nf_hooks[pf][hook]); +} +#else +static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook) +{ + return !list_empty(&nf_hooks[pf][hook]); +} +#endif + +int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state); + +/** + * 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 sock *sk, + struct sk_buff *skb, + struct net_device *indev, + struct net_device *outdev, + int (*okfn)(struct sock *, struct sk_buff *), + int thresh) +{ + if (nf_hooks_active(pf, hook)) { + struct nf_hook_state state; + + nf_hook_state_init(&state, hook, thresh, pf, + indev, outdev, sk, okfn); + return nf_hook_slow(skb, &state); + } + return 1; +} + +static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sock *sk, + struct sk_buff *skb, struct net_device *indev, + struct net_device *outdev, + int (*okfn)(struct sock *, struct sk_buff *)) +{ + return nf_hook_thresh(pf, hook, sk, 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 sock *sk, + struct sk_buff *skb, struct net_device *in, + struct net_device *out, + int (*okfn)(struct sock *, struct sk_buff *), int thresh) +{ + int ret = nf_hook_thresh(pf, hook, sk, skb, in, out, okfn, thresh); + if (ret == 1) + ret = okfn(sk, skb); + return ret; +} + +static inline int +NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sock *sk, + struct sk_buff *skb, struct net_device *in, struct net_device *out, + int (*okfn)(struct sock *, struct sk_buff *), bool cond) +{ + int ret; + + if (!cond || + ((ret = nf_hook_thresh(pf, hook, sk, skb, in, out, okfn, INT_MIN)) == 1)) + ret = okfn(sk, skb); + return ret; +} + +static inline int +NF_HOOK(uint8_t pf, unsigned int hook, struct sock *sk, struct sk_buff *skb, + struct net_device *in, struct net_device *out, + int (*okfn)(struct sock *, struct sk_buff *)) +{ + return NF_HOOK_THRESH(pf, hook, sk, 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. */ +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; +} + +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 */ +#define NF_HOOK(pf, hook, sk, skb, indev, outdev, okfn) (okfn)(sk, skb) +#define NF_HOOK_COND(pf, hook, sk, skb, indev, outdev, okfn, cond) (okfn)(sk, skb) +static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook, + struct sock *sk, + struct sk_buff *skb, + struct net_device *indev, + struct net_device *outdev, + int (*okfn)(struct sock *sk, struct sk_buff *), int thresh) +{ + return okfn(sk, skb); +} +static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sock *sk, + struct sk_buff *skb, struct net_device *indev, + struct net_device *outdev, + int (*okfn)(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) +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; + +struct nf_conn; +enum ip_conntrack_info; +struct nlattr; + +struct nfq_ct_hook { + size_t (*build_size)(const struct nf_conn *ct); + int (*build)(struct sk_buff *skb, struct nf_conn *ct); + 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 nfq_ct_hook __rcu *nfq_ct_hook; +#else +static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} +#endif + +#endif /*__LINUX_NETFILTER_H*/ |