1 #ifndef _IP_NAT_H 2 #define _IP_NAT_H 3 #include <linux/netfilter_ipv4.h> 4 #include <linux/netfilter_ipv4/ip_conntrack_tuple.h> 5 6 #define IP_NAT_MAPPING_TYPE_MAX_NAMELEN 16 7 8 enum ip_nat_manip_type 9 { 10 IP_NAT_MANIP_SRC, 11 IP_NAT_MANIP_DST 12 }; 13 14 /* SRC manip occurs POST_ROUTING or LOCAL_IN */ 15 #define HOOK2MANIP(hooknum) ((hooknum) != NF_IP_POST_ROUTING && (hooknum) != NF_IP_LOCAL_IN) 16 17 #define IP_NAT_RANGE_MAP_IPS 1 18 #define IP_NAT_RANGE_PROTO_SPECIFIED 2 19 20 /* NAT sequence number modifications */ 21 struct ip_nat_seq { 22 /* position of the last TCP sequence number 23 * modification (if any) */ 24 u_int32_t correction_pos; 25 /* sequence number offset before and after last modification */ 26 int16_t offset_before, offset_after; 27 }; 28 29 /* Single range specification. */ 30 struct ip_nat_range 31 { 32 /* Set to OR of flags above. */ 33 unsigned int flags; 34 35 /* Inclusive: network order. */ 36 u_int32_t min_ip, max_ip; 37 38 /* Inclusive: network order */ 39 union ip_conntrack_manip_proto min, max; 40 }; 41 42 /* For backwards compat: don't use in modern code. */ 43 struct ip_nat_multi_range_compat 44 { 45 unsigned int rangesize; /* Must be 1. */ 46 47 /* hangs off end. */ 48 struct ip_nat_range range[1]; 49 }; 50 51 #ifdef __KERNEL__ 52 #include <linux/list.h> 53 54 /* Protects NAT hash tables, and NAT-private part of conntracks. */ 55 extern rwlock_t ip_nat_lock; 56 57 /* The structure embedded in the conntrack structure. */ 58 struct ip_nat_info 59 { 60 struct list_head bysource; 61 struct ip_nat_seq seq[IP_CT_DIR_MAX]; 62 }; 63 64 struct ip_conntrack; 65 66 /* Set up the info structure to map into this range. */ 67 extern unsigned int ip_nat_setup_info(struct ip_conntrack *conntrack, 68 const struct ip_nat_range *range, 69 unsigned int hooknum); 70 71 /* Is this tuple already taken? (not by us)*/ 72 extern int ip_nat_used_tuple(const struct ip_conntrack_tuple *tuple, 73 const struct ip_conntrack *ignored_conntrack); 74 75 /* Calculate relative checksum. */ 76 extern u_int16_t ip_nat_cheat_check(u_int32_t oldvalinv, 77 u_int32_t newval, 78 u_int16_t oldcheck); 79 #else /* !__KERNEL__: iptables wants this to compile. */ 80 #define ip_nat_multi_range ip_nat_multi_range_compat 81 #endif /*__KERNEL__*/ 82 #endif 83