From 5b1158e909ecbe1a052203e0d8df15633f829930 Mon Sep 17 00:00:00 2001 From: Jozsef Kadlecsik Date: Sat, 2 Dec 2006 22:07:13 -0800 Subject: [NETFILTER]: Add NAT support for nf_conntrack Add NAT support for nf_conntrack. Joint work of Jozsef Kadlecsik, Yasuyuki Kozakai, Martin Josefsson and myself. Signed-off-by: Jozsef Kadlecsik Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- include/net/netfilter/ipv4/nf_conntrack_ipv4.h | 20 +++---- include/net/netfilter/nf_conntrack.h | 29 +++++++++- include/net/netfilter/nf_conntrack_expect.h | 2 +- include/net/netfilter/nf_nat.h | 77 ++++++++++++++++++++++++++ include/net/netfilter/nf_nat_core.h | 27 +++++++++ include/net/netfilter/nf_nat_helper.h | 32 +++++++++++ include/net/netfilter/nf_nat_protocol.h | 70 +++++++++++++++++++++++ include/net/netfilter/nf_nat_rule.h | 35 ++++++++++++ 8 files changed, 277 insertions(+), 15 deletions(-) create mode 100644 include/net/netfilter/nf_nat.h create mode 100644 include/net/netfilter/nf_nat_core.h create mode 100644 include/net/netfilter/nf_nat_helper.h create mode 100644 include/net/netfilter/nf_nat_protocol.h create mode 100644 include/net/netfilter/nf_nat_rule.h (limited to 'include/net') diff --git a/include/net/netfilter/ipv4/nf_conntrack_ipv4.h b/include/net/netfilter/ipv4/nf_conntrack_ipv4.h index 34b453a81a6..a1c57ee0a4f 100644 --- a/include/net/netfilter/ipv4/nf_conntrack_ipv4.h +++ b/include/net/netfilter/ipv4/nf_conntrack_ipv4.h @@ -9,29 +9,23 @@ #ifndef _NF_CONNTRACK_IPV4_H #define _NF_CONNTRACK_IPV4_H -#ifdef CONFIG_IP_NF_NAT_NEEDED -#include +#ifdef CONFIG_NF_NAT_NEEDED +#include /* per conntrack: nat application helper private data */ -union ip_conntrack_nat_help { +union nf_conntrack_nat_help { /* insert nat helper private data here */ }; -struct nf_conntrack_ipv4_nat { - struct ip_nat_info info; - union ip_conntrack_nat_help help; +struct nf_conn_nat { + struct nf_nat_info info; + union nf_conntrack_nat_help help; #if defined(CONFIG_IP_NF_TARGET_MASQUERADE) || \ defined(CONFIG_IP_NF_TARGET_MASQUERADE_MODULE) int masq_index; #endif }; -#endif /* CONFIG_IP_NF_NAT_NEEDED */ - -struct nf_conntrack_ipv4 { -#ifdef CONFIG_IP_NF_NAT_NEEDED - struct nf_conntrack_ipv4_nat *nat; -#endif -}; +#endif /* CONFIG_NF_NAT_NEEDED */ /* Returns new sk_buff, or NULL */ struct sk_buff * diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h index b4beb8c799e..9948af06868 100644 --- a/include/net/netfilter/nf_conntrack.h +++ b/include/net/netfilter/nf_conntrack.h @@ -264,18 +264,45 @@ nf_conntrack_unregister_cache(u_int32_t features); /* valid combinations: * basic: nf_conn, nf_conn .. nf_conn_help - * nat: nf_conn .. nf_conn_nat, nf_conn .. nf_conn_nat, nf_conn help + * nat: nf_conn .. nf_conn_nat, nf_conn .. nf_conn_nat .. nf_conn help */ +#ifdef CONFIG_NF_NAT_NEEDED +static inline struct nf_conn_nat *nfct_nat(const struct nf_conn *ct) +{ + unsigned int offset = sizeof(struct nf_conn); + + if (!(ct->features & NF_CT_F_NAT)) + return NULL; + + offset = ALIGN(offset, __alignof__(struct nf_conn_nat)); + return (struct nf_conn_nat *) ((void *)ct + offset); +} + static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct) { unsigned int offset = sizeof(struct nf_conn); if (!(ct->features & NF_CT_F_HELP)) return NULL; + if (ct->features & NF_CT_F_NAT) { + offset = ALIGN(offset, __alignof__(struct nf_conn_nat)); + offset += sizeof(struct nf_conn_nat); + } offset = ALIGN(offset, __alignof__(struct nf_conn_help)); return (struct nf_conn_help *) ((void *)ct + offset); } +#else /* No NAT */ +static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct) +{ + unsigned int offset = sizeof(struct nf_conn); + + if (!(ct->features & NF_CT_F_HELP)) + return NULL; + offset = ALIGN(offset, __alignof__(struct nf_conn_help)); + return (struct nf_conn_help *) ((void *)ct + offset); +} +#endif /* CONFIG_NF_NAT_NEEDED */ #endif /* __KERNEL__ */ #endif /* _NF_CONNTRACK_H */ diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h index 5d853e826d1..b969c430b36 100644 --- a/include/net/netfilter/nf_conntrack_expect.h +++ b/include/net/netfilter/nf_conntrack_expect.h @@ -43,7 +43,7 @@ struct nf_conntrack_expect #ifdef CONFIG_NF_NAT_NEEDED /* This is the original per-proto part, used to map the * expected connection the way the recipient expects. */ - union nf_conntrack_manip_proto saved_proto; + union nf_conntrack_man_proto saved_proto; /* Direction relative to the master connection. */ enum ip_conntrack_dir dir; #endif diff --git a/include/net/netfilter/nf_nat.h b/include/net/netfilter/nf_nat.h new file mode 100644 index 00000000000..61c62068ca6 --- /dev/null +++ b/include/net/netfilter/nf_nat.h @@ -0,0 +1,77 @@ +#ifndef _NF_NAT_H +#define _NF_NAT_H +#include +#include + +#define NF_NAT_MAPPING_TYPE_MAX_NAMELEN 16 + +enum nf_nat_manip_type +{ + IP_NAT_MANIP_SRC, + IP_NAT_MANIP_DST +}; + +/* SRC manip occurs POST_ROUTING or LOCAL_IN */ +#define HOOK2MANIP(hooknum) ((hooknum) != NF_IP_POST_ROUTING && (hooknum) != NF_IP_LOCAL_IN) + +#define IP_NAT_RANGE_MAP_IPS 1 +#define IP_NAT_RANGE_PROTO_SPECIFIED 2 + +/* NAT sequence number modifications */ +struct nf_nat_seq { + /* position of the last TCP sequence number modification (if any) */ + u_int32_t correction_pos; + + /* sequence number offset before and after last modification */ + int16_t offset_before, offset_after; +}; + +/* Single range specification. */ +struct nf_nat_range +{ + /* Set to OR of flags above. */ + unsigned int flags; + + /* Inclusive: network order. */ + __be32 min_ip, max_ip; + + /* Inclusive: network order */ + union nf_conntrack_man_proto min, max; +}; + +/* For backwards compat: don't use in modern code. */ +struct nf_nat_multi_range_compat +{ + unsigned int rangesize; /* Must be 1. */ + + /* hangs off end. */ + struct nf_nat_range range[1]; +}; + +#ifdef __KERNEL__ +#include + +/* The structure embedded in the conntrack structure. */ +struct nf_nat_info +{ + struct list_head bysource; + struct nf_nat_seq seq[IP_CT_DIR_MAX]; +}; + +struct nf_conn; + +/* Set up the info structure to map into this range. */ +extern unsigned int nf_nat_setup_info(struct nf_conn *ct, + const struct nf_nat_range *range, + unsigned int hooknum); + +/* Is this tuple already taken? (not by us)*/ +extern int nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple, + const struct nf_conn *ignored_conntrack); + +extern int nf_nat_module_is_loaded; + +#else /* !__KERNEL__: iptables wants this to compile. */ +#define nf_nat_multi_range nf_nat_multi_range_compat +#endif /*__KERNEL__*/ +#endif diff --git a/include/net/netfilter/nf_nat_core.h b/include/net/netfilter/nf_nat_core.h new file mode 100644 index 00000000000..9778ffa9344 --- /dev/null +++ b/include/net/netfilter/nf_nat_core.h @@ -0,0 +1,27 @@ +#ifndef _NF_NAT_CORE_H +#define _NF_NAT_CORE_H +#include +#include + +/* This header used to share core functionality between the standalone + NAT module, and the compatibility layer's use of NAT for masquerading. */ + +extern unsigned int nf_nat_packet(struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int hooknum, + struct sk_buff **pskb); + +extern int nf_nat_icmp_reply_translation(struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int hooknum, + struct sk_buff **pskb); + +static inline int nf_nat_initialized(struct nf_conn *ct, + enum nf_nat_manip_type manip) +{ + if (manip == IP_NAT_MANIP_SRC) + return test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status); + else + return test_bit(IPS_DST_NAT_DONE_BIT, &ct->status); +} +#endif /* _NF_NAT_CORE_H */ diff --git a/include/net/netfilter/nf_nat_helper.h b/include/net/netfilter/nf_nat_helper.h new file mode 100644 index 00000000000..ec98ecf95fc --- /dev/null +++ b/include/net/netfilter/nf_nat_helper.h @@ -0,0 +1,32 @@ +#ifndef _NF_NAT_HELPER_H +#define _NF_NAT_HELPER_H +/* NAT protocol helper routines. */ + +#include + +struct sk_buff; + +/* These return true or false. */ +extern int nf_nat_mangle_tcp_packet(struct sk_buff **skb, + struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int match_offset, + unsigned int match_len, + const char *rep_buffer, + unsigned int rep_len); +extern int nf_nat_mangle_udp_packet(struct sk_buff **skb, + struct nf_conn *ct, + enum ip_conntrack_info ctinfo, + unsigned int match_offset, + unsigned int match_len, + const char *rep_buffer, + unsigned int rep_len); +extern int nf_nat_seq_adjust(struct sk_buff **pskb, + struct nf_conn *ct, + enum ip_conntrack_info ctinfo); + +/* Setup NAT on this expected conntrack so it follows master, but goes + * to port ct->master->saved_proto. */ +extern void nf_nat_follow_master(struct nf_conn *ct, + struct nf_conntrack_expect *this); +#endif diff --git a/include/net/netfilter/nf_nat_protocol.h b/include/net/netfilter/nf_nat_protocol.h new file mode 100644 index 00000000000..a9ec5ef6146 --- /dev/null +++ b/include/net/netfilter/nf_nat_protocol.h @@ -0,0 +1,70 @@ +/* Header for use in defining a given protocol. */ +#ifndef _NF_NAT_PROTOCOL_H +#define _NF_NAT_PROTOCOL_H +#include +#include + +struct nf_nat_range; + +struct nf_nat_protocol +{ + /* Protocol name */ + const char *name; + + /* Protocol number. */ + unsigned int protonum; + + struct module *me; + + /* Translate a packet to the target according to manip type. + Return true if succeeded. */ + int (*manip_pkt)(struct sk_buff **pskb, + unsigned int iphdroff, + const struct nf_conntrack_tuple *tuple, + enum nf_nat_manip_type maniptype); + + /* Is the manipable part of the tuple between min and max incl? */ + int (*in_range)(const struct nf_conntrack_tuple *tuple, + enum nf_nat_manip_type maniptype, + const union nf_conntrack_man_proto *min, + const union nf_conntrack_man_proto *max); + + /* Alter the per-proto part of the tuple (depending on + maniptype), to give a unique tuple in the given range if + possible; return false if not. Per-protocol part of tuple + is initialized to the incoming packet. */ + int (*unique_tuple)(struct nf_conntrack_tuple *tuple, + const struct nf_nat_range *range, + enum nf_nat_manip_type maniptype, + const struct nf_conn *ct); + + int (*range_to_nfattr)(struct sk_buff *skb, + const struct nf_nat_range *range); + + int (*nfattr_to_range)(struct nfattr *tb[], + struct nf_nat_range *range); +}; + +/* Protocol registration. */ +extern int nf_nat_protocol_register(struct nf_nat_protocol *proto); +extern void nf_nat_protocol_unregister(struct nf_nat_protocol *proto); + +extern struct nf_nat_protocol *nf_nat_proto_find_get(u_int8_t protocol); +extern void nf_nat_proto_put(struct nf_nat_protocol *proto); + +/* Built-in protocols. */ +extern struct nf_nat_protocol nf_nat_protocol_tcp; +extern struct nf_nat_protocol nf_nat_protocol_udp; +extern struct nf_nat_protocol nf_nat_protocol_icmp; +extern struct nf_nat_protocol nf_nat_unknown_protocol; + +extern int init_protocols(void) __init; +extern void cleanup_protocols(void); +extern struct nf_nat_protocol *find_nat_proto(u_int16_t protonum); + +extern int nf_nat_port_range_to_nfattr(struct sk_buff *skb, + const struct nf_nat_range *range); +extern int nf_nat_port_nfattr_to_range(struct nfattr *tb[], + struct nf_nat_range *range); + +#endif /*_NF_NAT_PROTO_H*/ diff --git a/include/net/netfilter/nf_nat_rule.h b/include/net/netfilter/nf_nat_rule.h new file mode 100644 index 00000000000..f191c672bcc --- /dev/null +++ b/include/net/netfilter/nf_nat_rule.h @@ -0,0 +1,35 @@ +#ifndef _NF_NAT_RULE_H +#define _NF_NAT_RULE_H +#include +#include +#include + +/* Compatibility definitions for ipt_FOO modules */ +#define ip_nat_range nf_nat_range +#define ip_conntrack_tuple nf_conntrack_tuple +#define ip_conntrack_get nf_ct_get +#define ip_conntrack nf_conn +#define ip_nat_setup_info nf_nat_setup_info +#define ip_nat_multi_range_compat nf_nat_multi_range_compat +#define ip_ct_iterate_cleanup nf_ct_iterate_cleanup +#define IP_NF_ASSERT NF_CT_ASSERT + +extern int nf_nat_rule_init(void) __init; +extern void nf_nat_rule_cleanup(void); +extern int nf_nat_rule_find(struct sk_buff **pskb, + unsigned int hooknum, + const struct net_device *in, + const struct net_device *out, + struct nf_conn *ct, + struct nf_nat_info *info); + +extern unsigned int +alloc_null_binding(struct nf_conn *ct, + struct nf_nat_info *info, + unsigned int hooknum); + +extern unsigned int +alloc_null_binding_confirmed(struct nf_conn *ct, + struct nf_nat_info *info, + unsigned int hooknum); +#endif /* _NF_NAT_RULE_H */ -- cgit v1.2.3-70-g09d2