1 /* 2 * connection tracking helpers. 3 * 4 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp> 5 * - generalize L3 protocol dependent part. 6 * 7 * Derived from include/linux/netfiter_ipv4/ip_conntrack_helper.h 8 */ 9 10 #ifndef _NF_CONNTRACK_HELPER_H 11 #define _NF_CONNTRACK_HELPER_H 12 #include <net/netfilter/nf_conntrack.h> 13 #include <net/netfilter/nf_conntrack_extend.h> 14 #include <net/netfilter/nf_conntrack_expect.h> 15 16 struct module; 17 18 enum nf_ct_helper_flags { 19 NF_CT_HELPER_F_USERSPACE = (1 << 0), 20 NF_CT_HELPER_F_CONFIGURED = (1 << 1), 21 }; 22 23 #define NF_CT_HELPER_NAME_LEN 16 24 25 struct nf_conntrack_helper { 26 struct hlist_node hnode; /* Internal use. */ 27 28 char name[NF_CT_HELPER_NAME_LEN]; /* name of the module */ 29 struct module *me; /* pointer to self */ 30 const struct nf_conntrack_expect_policy *expect_policy; 31 32 /* length of internal data, ie. sizeof(struct nf_ct_*_master) */ 33 size_t data_len; 34 35 /* Tuple of things we will help (compared against server response) */ 36 struct nf_conntrack_tuple tuple; 37 38 /* Function to call when data passes; return verdict, or -1 to 39 invalidate. */ 40 int (*help)(struct sk_buff *skb, 41 unsigned int protoff, 42 struct nf_conn *ct, 43 enum ip_conntrack_info conntrackinfo); 44 45 void (*destroy)(struct nf_conn *ct); 46 47 int (*from_nlattr)(struct nlattr *attr, struct nf_conn *ct); 48 int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct); 49 unsigned int expect_class_max; 50 51 unsigned int flags; 52 unsigned int queue_num; /* For user-space helpers. */ 53 }; 54 55 extern struct nf_conntrack_helper * 56 __nf_conntrack_helper_find(const char *name, u16 l3num, u8 protonum); 57 58 extern struct nf_conntrack_helper * 59 nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum); 60 61 extern int nf_conntrack_helper_register(struct nf_conntrack_helper *); 62 extern void nf_conntrack_helper_unregister(struct nf_conntrack_helper *); 63 64 extern struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, struct nf_conntrack_helper *helper, gfp_t gfp); 65 66 extern int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl, 67 gfp_t flags); 68 69 extern void nf_ct_helper_destroy(struct nf_conn *ct); 70 71 static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct) 72 { 73 return nf_ct_ext_find(ct, NF_CT_EXT_HELPER); 74 } 75 76 static inline void *nfct_help_data(const struct nf_conn *ct) 77 { 78 struct nf_conn_help *help; 79 80 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER); 81 82 return (void *)help->data; 83 } 84 85 extern int nf_conntrack_helper_init(struct net *net); 86 extern void nf_conntrack_helper_fini(struct net *net); 87 88 extern int nf_conntrack_broadcast_help(struct sk_buff *skb, 89 unsigned int protoff, 90 struct nf_conn *ct, 91 enum ip_conntrack_info ctinfo, 92 unsigned int timeout); 93 94 struct nf_ct_helper_expectfn { 95 struct list_head head; 96 const char *name; 97 void (*expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp); 98 }; 99 100 void nf_ct_helper_expectfn_register(struct nf_ct_helper_expectfn *n); 101 void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n); 102 struct nf_ct_helper_expectfn * 103 nf_ct_helper_expectfn_find_by_name(const char *name); 104 struct nf_ct_helper_expectfn * 105 nf_ct_helper_expectfn_find_by_symbol(const void *symbol); 106 107 extern struct hlist_head *nf_ct_helper_hash; 108 extern unsigned int nf_ct_helper_hsize; 109 110 #endif /*_NF_CONNTRACK_HELPER_H*/ 111