From c4b885139203d37f76662c37ae645fe8e0f4e4e5 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 20 Mar 2006 18:03:40 -0800 Subject: [PATCH] [NETFILTER]: x_tables: replace IPv4/IPv6 policy match by address family independant version Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- include/linux/netfilter/x_tables.h | 4 + include/linux/netfilter/xt_policy.h | 58 ++++++ include/linux/netfilter_ipv4/ipt_policy.h | 69 ++----- include/linux/netfilter_ipv6/ip6t_policy.h | 69 ++----- net/ipv4/netfilter/Kconfig | 10 - net/ipv4/netfilter/Makefile | 1 - net/ipv4/netfilter/ipt_policy.c | 174 ----------------- net/ipv6/netfilter/Kconfig | 10 - net/ipv6/netfilter/Makefile | 1 - net/ipv6/netfilter/ip6t_policy.c | 174 ----------------- net/netfilter/Kconfig | 10 + net/netfilter/Makefile | 1 + net/netfilter/xt_policy.c | 209 +++++++++++++++++++++ 13 files changed, 314 insertions(+), 476 deletions(-) create mode 100644 include/linux/netfilter/xt_policy.h delete mode 100644 net/ipv4/netfilter/ipt_policy.c delete mode 100644 net/ipv6/netfilter/ip6t_policy.c create mode 100644 net/netfilter/xt_policy.c diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 2fdbc4a446..46a0f974f8 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -126,6 +126,8 @@ struct xt_match unsigned int matchsize; unsigned int hooks; unsigned short proto; + + unsigned short family; u_int8_t revision; }; @@ -169,6 +171,8 @@ struct xt_target unsigned int targetsize; unsigned int hooks; unsigned short proto; + + unsigned short family; u_int8_t revision; }; diff --git a/include/linux/netfilter/xt_policy.h b/include/linux/netfilter/xt_policy.h new file mode 100644 index 0000000000..a8132ec076 --- /dev/null +++ b/include/linux/netfilter/xt_policy.h @@ -0,0 +1,58 @@ +#ifndef _XT_POLICY_H +#define _XT_POLICY_H + +#define XT_POLICY_MAX_ELEM 4 + +enum xt_policy_flags +{ + XT_POLICY_MATCH_IN = 0x1, + XT_POLICY_MATCH_OUT = 0x2, + XT_POLICY_MATCH_NONE = 0x4, + XT_POLICY_MATCH_STRICT = 0x8, +}; + +enum xt_policy_modes +{ + XT_POLICY_MODE_TRANSPORT, + XT_POLICY_MODE_TUNNEL +}; + +struct xt_policy_spec +{ + u_int8_t saddr:1, + daddr:1, + proto:1, + mode:1, + spi:1, + reqid:1; +}; + +union xt_policy_addr +{ + struct in_addr a4; + struct in6_addr a6; +}; + +struct xt_policy_elem +{ + union xt_policy_addr saddr; + union xt_policy_addr smask; + union xt_policy_addr daddr; + union xt_policy_addr dmask; + u_int32_t spi; + u_int32_t reqid; + u_int8_t proto; + u_int8_t mode; + + struct xt_policy_spec match; + struct xt_policy_spec invert; +}; + +struct xt_policy_info +{ + struct xt_policy_elem pol[XT_POLICY_MAX_ELEM]; + u_int16_t flags; + u_int16_t len; +}; + +#endif /* _XT_POLICY_H */ diff --git a/include/linux/netfilter_ipv4/ipt_policy.h b/include/linux/netfilter_ipv4/ipt_policy.h index a3f6eff39d..b9478a2553 100644 --- a/include/linux/netfilter_ipv4/ipt_policy.h +++ b/include/linux/netfilter_ipv4/ipt_policy.h @@ -1,58 +1,21 @@ #ifndef _IPT_POLICY_H #define _IPT_POLICY_H -#define IPT_POLICY_MAX_ELEM 4 - -enum ipt_policy_flags -{ - IPT_POLICY_MATCH_IN = 0x1, - IPT_POLICY_MATCH_OUT = 0x2, - IPT_POLICY_MATCH_NONE = 0x4, - IPT_POLICY_MATCH_STRICT = 0x8, -}; - -enum ipt_policy_modes -{ - IPT_POLICY_MODE_TRANSPORT, - IPT_POLICY_MODE_TUNNEL -}; - -struct ipt_policy_spec -{ - u_int8_t saddr:1, - daddr:1, - proto:1, - mode:1, - spi:1, - reqid:1; -}; - -union ipt_policy_addr -{ - struct in_addr a4; - struct in6_addr a6; -}; - -struct ipt_policy_elem -{ - union ipt_policy_addr saddr; - union ipt_policy_addr smask; - union ipt_policy_addr daddr; - union ipt_policy_addr dmask; - u_int32_t spi; - u_int32_t reqid; - u_int8_t proto; - u_int8_t mode; - - struct ipt_policy_spec match; - struct ipt_policy_spec invert; -}; - -struct ipt_policy_info -{ - struct ipt_policy_elem pol[IPT_POLICY_MAX_ELEM]; - u_int16_t flags; - u_int16_t len; -}; +#define IPT_POLICY_MAX_ELEM XT_POLICY_MAX_ELEM + +/* ipt_policy_flags */ +#define IPT_POLICY_MATCH_IN XT_POLICY_MATCH_IN +#define IPT_POLICY_MATCH_OUT XT_POLICY_MATCH_OUT +#define IPT_POLICY_MATCH_NONE XT_POLICY_MATCH_NONE +#define IPT_POLICY_MATCH_STRICT XT_POLICY_MATCH_STRICT + +/* ipt_policy_modes */ +#define IPT_POLICY_MODE_TRANSPORT XT_POLICY_MODE_TRANSPORT +#define IPT_POLICY_MODE_TUNNEL XT_POLICY_MODE_TUNNEL + +#define ipt_policy_spec xt_policy_spec +#define ipt_policy_addr xt_policy_addr +#define ipt_policy_elem xt_policy_elem +#define ipt_policy_info xt_policy_info #endif /* _IPT_POLICY_H */ diff --git a/include/linux/netfilter_ipv6/ip6t_policy.h b/include/linux/netfilter_ipv6/ip6t_policy.h index 671bd81830..6bab3163d2 100644 --- a/include/linux/netfilter_ipv6/ip6t_policy.h +++ b/include/linux/netfilter_ipv6/ip6t_policy.h @@ -1,58 +1,21 @@ #ifndef _IP6T_POLICY_H #define _IP6T_POLICY_H -#define IP6T_POLICY_MAX_ELEM 4 - -enum ip6t_policy_flags -{ - IP6T_POLICY_MATCH_IN = 0x1, - IP6T_POLICY_MATCH_OUT = 0x2, - IP6T_POLICY_MATCH_NONE = 0x4, - IP6T_POLICY_MATCH_STRICT = 0x8, -}; - -enum ip6t_policy_modes -{ - IP6T_POLICY_MODE_TRANSPORT, - IP6T_POLICY_MODE_TUNNEL -}; - -struct ip6t_policy_spec -{ - u_int8_t saddr:1, - daddr:1, - proto:1, - mode:1, - spi:1, - reqid:1; -}; - -union ip6t_policy_addr -{ - struct in_addr a4; - struct in6_addr a6; -}; - -struct ip6t_policy_elem -{ - union ip6t_policy_addr saddr; - union ip6t_policy_addr smask; - union ip6t_policy_addr daddr; - union ip6t_policy_addr dmask; - u_int32_t spi; - u_int32_t reqid; - u_int8_t proto; - u_int8_t mode; - - struct ip6t_policy_spec match; - struct ip6t_policy_spec invert; -}; - -struct ip6t_policy_info -{ - struct ip6t_policy_elem pol[IP6T_POLICY_MAX_ELEM]; - u_int16_t flags; - u_int16_t len; -}; +#define IP6T_POLICY_MAX_ELEM XT_POLICY_MAX_ELEM + +/* ip6t_policy_flags */ +#define IP6T_POLICY_MATCH_IN XT_POLICY_MATCH_IN +#define IP6T_POLICY_MATCH_OUT XT_POLICY_MATCH_OUT +#define IP6T_POLICY_MATCH_NONE XT_POLICY_MATCH_NONE +#define IP6T_POLICY_MATCH_STRICT XT_POLICY_MATCH_STRICT + +/* ip6t_policy_modes */ +#define IP6T_POLICY_MODE_TRANSPORT XT_POLICY_MODE_TRANSPORT +#define IP6T_POLICY_MODE_TUNNEL XT_POLICY_MODE_TUNNEL + +#define ip6t_policy_spec xt_policy_spec +#define ip6t_policy_addr xt_policy_addr +#define ip6t_policy_elem xt_policy_elem +#define ip6t_policy_info xt_policy_info #endif /* _IP6T_POLICY_H */ diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig index db783036e4..933ee7a9ef 100644 --- a/net/ipv4/netfilter/Kconfig +++ b/net/ipv4/netfilter/Kconfig @@ -303,16 +303,6 @@ config IP_NF_MATCH_HASHLIMIT destination IP' or `500pps from any given source IP' with a single IPtables rule. -config IP_NF_MATCH_POLICY - tristate "IPsec policy match support" - depends on IP_NF_IPTABLES && XFRM - help - Policy matching allows you to match packets based on the - IPsec policy that was used during decapsulation/will - be used during encapsulation. - - To compile it as a module, choose M here. If unsure, say N. - # `filter', generic and specific targets config IP_NF_FILTER tristate "Packet filtering" diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile index e5c5b3202f..3fe80924ac 100644 --- a/net/ipv4/netfilter/Makefile +++ b/net/ipv4/netfilter/Makefile @@ -57,7 +57,6 @@ obj-$(CONFIG_IP_NF_MATCH_DSCP) += ipt_dscp.o obj-$(CONFIG_IP_NF_MATCH_AH_ESP) += ipt_ah.o ipt_esp.o obj-$(CONFIG_IP_NF_MATCH_TTL) += ipt_ttl.o obj-$(CONFIG_IP_NF_MATCH_ADDRTYPE) += ipt_addrtype.o -obj-$(CONFIG_IP_NF_MATCH_POLICY) += ipt_policy.o # targets obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o diff --git a/net/ipv4/netfilter/ipt_policy.c b/net/ipv4/netfilter/ipt_policy.c deleted file mode 100644 index b73f590b22..0000000000 --- a/net/ipv4/netfilter/ipt_policy.c +++ /dev/null @@ -1,174 +0,0 @@ -/* IP tables module for matching IPsec policy - * - * Copyright (c) 2004,2005 Patrick McHardy, - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ - -#include -#include -#include -#include -#include -#include - -#include -#include -#include - -MODULE_AUTHOR("Patrick McHardy "); -MODULE_DESCRIPTION("IPtables IPsec policy matching module"); -MODULE_LICENSE("GPL"); - - -static inline int -match_xfrm_state(struct xfrm_state *x, const struct ipt_policy_elem *e) -{ -#define MATCH_ADDR(x,y,z) (!e->match.x || \ - ((e->x.a4.s_addr == (e->y.a4.s_addr & (z))) \ - ^ e->invert.x)) -#define MATCH(x,y) (!e->match.x || ((e->x == (y)) ^ e->invert.x)) - - return MATCH_ADDR(saddr, smask, x->props.saddr.a4) && - MATCH_ADDR(daddr, dmask, x->id.daddr.a4) && - MATCH(proto, x->id.proto) && - MATCH(mode, x->props.mode) && - MATCH(spi, x->id.spi) && - MATCH(reqid, x->props.reqid); -} - -static int -match_policy_in(const struct sk_buff *skb, const struct ipt_policy_info *info) -{ - const struct ipt_policy_elem *e; - struct sec_path *sp = skb->sp; - int strict = info->flags & IPT_POLICY_MATCH_STRICT; - int i, pos; - - if (sp == NULL) - return -1; - if (strict && info->len != sp->len) - return 0; - - for (i = sp->len - 1; i >= 0; i--) { - pos = strict ? i - sp->len + 1 : 0; - if (pos >= info->len) - return 0; - e = &info->pol[pos]; - - if (match_xfrm_state(sp->x[i].xvec, e)) { - if (!strict) - return 1; - } else if (strict) - return 0; - } - - return strict ? 1 : 0; -} - -static int -match_policy_out(const struct sk_buff *skb, const struct ipt_policy_info *info) -{ - const struct ipt_policy_elem *e; - struct dst_entry *dst = skb->dst; - int strict = info->flags & IPT_POLICY_MATCH_STRICT; - int i, pos; - - if (dst->xfrm == NULL) - return -1; - - for (i = 0; dst && dst->xfrm; dst = dst->child, i++) { - pos = strict ? i : 0; - if (pos >= info->len) - return 0; - e = &info->pol[pos]; - - if (match_xfrm_state(dst->xfrm, e)) { - if (!strict) - return 1; - } else if (strict) - return 0; - } - - return strict ? i == info->len : 0; -} - -static int match(const struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - const struct xt_match *match, - const void *matchinfo, - int offset, - unsigned int protoff, - int *hotdrop) -{ - const struct ipt_policy_info *info = matchinfo; - int ret; - - if (info->flags & IPT_POLICY_MATCH_IN) - ret = match_policy_in(skb, info); - else - ret = match_policy_out(skb, info); - - if (ret < 0) - ret = info->flags & IPT_POLICY_MATCH_NONE ? 1 : 0; - else if (info->flags & IPT_POLICY_MATCH_NONE) - ret = 0; - - return ret; -} - -static int checkentry(const char *tablename, const void *ip_void, - const struct xt_match *match, - void *matchinfo, unsigned int matchsize, - unsigned int hook_mask) -{ - struct ipt_policy_info *info = matchinfo; - - if (!(info->flags & (IPT_POLICY_MATCH_IN|IPT_POLICY_MATCH_OUT))) { - printk(KERN_ERR "ipt_policy: neither incoming nor " - "outgoing policy selected\n"); - return 0; - } - if (hook_mask & (1 << NF_IP_PRE_ROUTING | 1 << NF_IP_LOCAL_IN) - && info->flags & IPT_POLICY_MATCH_OUT) { - printk(KERN_ERR "ipt_policy: output policy not valid in " - "PRE_ROUTING and INPUT\n"); - return 0; - } - if (hook_mask & (1 << NF_IP_POST_ROUTING | 1 << NF_IP_LOCAL_OUT) - && info->flags & IPT_POLICY_MATCH_IN) { - printk(KERN_ERR "ipt_policy: input policy not valid in " - "POST_ROUTING and OUTPUT\n"); - return 0; - } - if (info->len > IPT_POLICY_MAX_ELEM) { - printk(KERN_ERR "ipt_policy: too many policy elements\n"); - return 0; - } - - return 1; -} - -static struct ipt_match policy_match = { - .name = "policy", - .match = match, - .matchsize = sizeof(struct ipt_policy_info), - .checkentry = checkentry, - .me = THIS_MODULE, -}; - -static int __init init(void) -{ - return ipt_register_match(&policy_match); -} - -static void __exit fini(void) -{ - ipt_unregister_match(&policy_match); -} - -module_init(init); -module_exit(fini); diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig index 2d6f8ecbc2..98f78759f1 100644 --- a/net/ipv6/netfilter/Kconfig +++ b/net/ipv6/netfilter/Kconfig @@ -133,16 +133,6 @@ config IP6_NF_MATCH_EUI64 To compile it as a module, choose M here. If unsure, say N. -config IP6_NF_MATCH_POLICY - tristate "IPsec policy match support" - depends on IP6_NF_IPTABLES && XFRM - help - Policy matching allows you to match packets based on the - IPsec policy that was used during decapsulation/will - be used during encapsulation. - - To compile it as a module, choose M here. If unsure, say N. - # The targets config IP6_NF_FILTER tristate "Packet filtering" diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile index db6073c941..8436a1a173 100644 --- a/net/ipv6/netfilter/Makefile +++ b/net/ipv6/netfilter/Makefile @@ -9,7 +9,6 @@ obj-$(CONFIG_IP6_NF_MATCH_OPTS) += ip6t_hbh.o ip6t_dst.o obj-$(CONFIG_IP6_NF_MATCH_IPV6HEADER) += ip6t_ipv6header.o obj-$(CONFIG_IP6_NF_MATCH_FRAG) += ip6t_frag.o obj-$(CONFIG_IP6_NF_MATCH_AHESP) += ip6t_esp.o ip6t_ah.o -obj-$(CONFIG_IP6_NF_MATCH_POLICY) += ip6t_policy.o obj-$(CONFIG_IP6_NF_MATCH_EUI64) += ip6t_eui64.o obj-$(CONFIG_IP6_NF_MATCH_MULTIPORT) += ip6t_multiport.o obj-$(CONFIG_IP6_NF_MATCH_OWNER) += ip6t_owner.o diff --git a/net/ipv6/netfilter/ip6t_policy.c b/net/ipv6/netfilter/ip6t_policy.c deleted file mode 100644 index f2a59970e0..0000000000 --- a/net/ipv6/netfilter/ip6t_policy.c +++ /dev/null @@ -1,174 +0,0 @@ -/* IP tables module for matching IPsec policy - * - * Copyright (c) 2004,2005 Patrick McHardy, - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ - -#include -#include -#include -#include -#include -#include - -#include -#include -#include - -MODULE_AUTHOR("Patrick McHardy "); -MODULE_DESCRIPTION("IPtables IPsec policy matching module"); -MODULE_LICENSE("GPL"); - - -static inline int -match_xfrm_state(struct xfrm_state *x, const struct ip6t_policy_elem *e) -{ -#define MATCH_ADDR(x,y,z) (!e->match.x || \ - ((!ipv6_masked_addr_cmp(&e->x.a6, &e->y.a6, \ - z)) \ - ^ e->invert.x)) -#define MATCH(x,y) (!e->match.x || ((e->x == (y)) ^ e->invert.x)) - - return MATCH_ADDR(saddr, smask, (struct in6_addr *)&x->props.saddr.a6) && - MATCH_ADDR(daddr, dmask, (struct in6_addr *)&x->id.daddr.a6) && - MATCH(proto, x->id.proto) && - MATCH(mode, x->props.mode) && - MATCH(spi, x->id.spi) && - MATCH(reqid, x->props.reqid); -} - -static int -match_policy_in(const struct sk_buff *skb, const struct ip6t_policy_info *info) -{ - const struct ip6t_policy_elem *e; - struct sec_path *sp = skb->sp; - int strict = info->flags & IP6T_POLICY_MATCH_STRICT; - int i, pos; - - if (sp == NULL) - return -1; - if (strict && info->len != sp->len) - return 0; - - for (i = sp->len - 1; i >= 0; i--) { - pos = strict ? i - sp->len + 1 : 0; - if (pos >= info->len) - return 0; - e = &info->pol[pos]; - - if (match_xfrm_state(sp->x[i].xvec, e)) { - if (!strict) - return 1; - } else if (strict) - return 0; - } - - return strict ? 1 : 0; -} - -static int -match_policy_out(const struct sk_buff *skb, const struct ip6t_policy_info *info) -{ - const struct ip6t_policy_elem *e; - struct dst_entry *dst = skb->dst; - int strict = info->flags & IP6T_POLICY_MATCH_STRICT; - int i, pos; - - if (dst->xfrm == NULL) - return -1; - - for (i = 0; dst && dst->xfrm; dst = dst->child, i++) { - pos = strict ? i : 0; - if (pos >= info->len) - return 0; - e = &info->pol[pos]; - - if (match_xfrm_state(dst->xfrm, e)) { - if (!strict) - return 1; - } else if (strict) - return 0; - } - - return strict ? i == info->len : 0; -} - -static int match(const struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - const struct xt_match *match, - const void *matchinfo, - int offset, - unsigned int protoff, - int *hotdrop) -{ - const struct ip6t_policy_info *info = matchinfo; - int ret; - - if (info->flags & IP6T_POLICY_MATCH_IN) - ret = match_policy_in(skb, info); - else - ret = match_policy_out(skb, info); - - if (ret < 0) - ret = info->flags & IP6T_POLICY_MATCH_NONE ? 1 : 0; - else if (info->flags & IP6T_POLICY_MATCH_NONE) - ret = 0; - - return ret; -} - -static int checkentry(const char *tablename, const void *ip_void, - const struct xt_match *match, void *matchinfo, - unsigned int matchsize, unsigned int hook_mask) -{ - struct ip6t_policy_info *info = matchinfo; - - if (!(info->flags & (IP6T_POLICY_MATCH_IN|IP6T_POLICY_MATCH_OUT))) { - printk(KERN_ERR "ip6t_policy: neither incoming nor " - "outgoing policy selected\n"); - return 0; - } - if (hook_mask & (1 << NF_IP6_PRE_ROUTING | 1 << NF_IP6_LOCAL_IN) - && info->flags & IP6T_POLICY_MATCH_OUT) { - printk(KERN_ERR "ip6t_policy: output policy not valid in " - "PRE_ROUTING and INPUT\n"); - return 0; - } - if (hook_mask & (1 << NF_IP6_POST_ROUTING | 1 << NF_IP6_LOCAL_OUT) - && info->flags & IP6T_POLICY_MATCH_IN) { - printk(KERN_ERR "ip6t_policy: input policy not valid in " - "POST_ROUTING and OUTPUT\n"); - return 0; - } - if (info->len > IP6T_POLICY_MAX_ELEM) { - printk(KERN_ERR "ip6t_policy: too many policy elements\n"); - return 0; - } - - return 1; -} - -static struct ip6t_match policy_match = { - .name = "policy", - .match = match, - .matchsize = sizeof(struct ip6t_policy_info), - .checkentry = checkentry, - .me = THIS_MODULE, -}; - -static int __init init(void) -{ - return ip6t_register_match(&policy_match); -} - -static void __exit fini(void) -{ - ip6t_unregister_match(&policy_match); -} - -module_init(init); -module_exit(fini); diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index a8e5544da9..1740278091 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -279,6 +279,16 @@ config NETFILTER_XT_MATCH_MARK To compile it as a module, choose M here. If unsure, say N. +config NETFILTER_XT_MATCH_POLICY + tristate 'IPsec "policy" match support' + depends on NETFILTER_XTABLES && XFRM + help + Policy matching allows you to match packets based on the + IPsec policy that was used during decapsulation/will + be used during encapsulation. + + To compile it as a module, choose M here. If unsure, say N. + config NETFILTER_XT_MATCH_PHYSDEV tristate '"physdev" match support' depends on NETFILTER_XTABLES && BRIDGE_NETFILTER diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index 746172ebc9..9558727f5e 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -40,6 +40,7 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_LENGTH) += xt_length.o obj-$(CONFIG_NETFILTER_XT_MATCH_LIMIT) += xt_limit.o obj-$(CONFIG_NETFILTER_XT_MATCH_MAC) += xt_mac.o obj-$(CONFIG_NETFILTER_XT_MATCH_MARK) += xt_mark.o +obj-$(CONFIG_NETFILTER_XT_MATCH_POLICY) += xt_policy.o obj-$(CONFIG_NETFILTER_XT_MATCH_PKTTYPE) += xt_pkttype.o obj-$(CONFIG_NETFILTER_XT_MATCH_REALM) += xt_realm.o obj-$(CONFIG_NETFILTER_XT_MATCH_SCTP) += xt_sctp.o diff --git a/net/netfilter/xt_policy.c b/net/netfilter/xt_policy.c new file mode 100644 index 0000000000..1ec22082f0 --- /dev/null +++ b/net/netfilter/xt_policy.c @@ -0,0 +1,209 @@ +/* IP tables module for matching IPsec policy + * + * Copyright (c) 2004,2005 Patrick McHardy, + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include + +#include +#include + +MODULE_AUTHOR("Patrick McHardy "); +MODULE_DESCRIPTION("Xtables IPsec policy matching module"); +MODULE_LICENSE("GPL"); + +static inline int +xt_addr_cmp(const union xt_policy_addr *a1, const union xt_policy_addr *m, + const union xt_policy_addr *a2, unsigned short family) +{ + switch (family) { + case AF_INET: + return (a1->a4.s_addr ^ a2->a4.s_addr) & m->a4.s_addr; + case AF_INET6: + return ipv6_masked_addr_cmp(&a1->a6, &m->a6, &a2->a6); + } + return 0; +} + +static inline int +match_xfrm_state(struct xfrm_state *x, const struct xt_policy_elem *e, + unsigned short family) +{ +#define MATCH_ADDR(x,y,z) (!e->match.x || \ + (xt_addr_cmp(&e->x, &e->y, z, family) \ + ^ e->invert.x)) +#define MATCH(x,y) (!e->match.x || ((e->x == (y)) ^ e->invert.x)) + + return MATCH_ADDR(saddr, smask, (union xt_policy_addr *)&x->props.saddr) && + MATCH_ADDR(daddr, dmask, (union xt_policy_addr *)&x->id.daddr.a4) && + MATCH(proto, x->id.proto) && + MATCH(mode, x->props.mode) && + MATCH(spi, x->id.spi) && + MATCH(reqid, x->props.reqid); +} + +static int +match_policy_in(const struct sk_buff *skb, const struct xt_policy_info *info, + unsigned short family) +{ + const struct xt_policy_elem *e; + struct sec_path *sp = skb->sp; + int strict = info->flags & XT_POLICY_MATCH_STRICT; + int i, pos; + + if (sp == NULL) + return -1; + if (strict && info->len != sp->len) + return 0; + + for (i = sp->len - 1; i >= 0; i--) { + pos = strict ? i - sp->len + 1 : 0; + if (pos >= info->len) + return 0; + e = &info->pol[pos]; + + if (match_xfrm_state(sp->x[i].xvec, e, family)) { + if (!strict) + return 1; + } else if (strict) + return 0; + } + + return strict ? 1 : 0; +} + +static int +match_policy_out(const struct sk_buff *skb, const struct xt_policy_info *info, + unsigned short family) +{ + const struct xt_policy_elem *e; + struct dst_entry *dst = skb->dst; + int strict = info->flags & XT_POLICY_MATCH_STRICT; + int i, pos; + + if (dst->xfrm == NULL) + return -1; + + for (i = 0; dst && dst->xfrm; dst = dst->child, i++) { + pos = strict ? i : 0; + if (pos >= info->len) + return 0; + e = &info->pol[pos]; + + if (match_xfrm_state(dst->xfrm, e, family)) { + if (!strict) + return 1; + } else if (strict) + return 0; + } + + return strict ? i == info->len : 0; +} + +static int match(const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const struct xt_match *match, + const void *matchinfo, + int offset, + unsigned int protoff, + int *hotdrop) +{ + const struct xt_policy_info *info = matchinfo; + int ret; + + if (info->flags & XT_POLICY_MATCH_IN) + ret = match_policy_in(skb, info, match->family); + else + ret = match_policy_out(skb, info, match->family); + + if (ret < 0) + ret = info->flags & XT_POLICY_MATCH_NONE ? 1 : 0; + else if (info->flags & XT_POLICY_MATCH_NONE) + ret = 0; + + return ret; +} + +static int checkentry(const char *tablename, const void *ip_void, + const struct xt_match *match, + void *matchinfo, unsigned int matchsize, + unsigned int hook_mask) +{ + struct xt_policy_info *info = matchinfo; + + if (!(info->flags & (XT_POLICY_MATCH_IN|XT_POLICY_MATCH_OUT))) { + printk(KERN_ERR "xt_policy: neither incoming nor " + "outgoing policy selected\n"); + return 0; + } + /* hook values are equal for IPv4 and IPv6 */ + if (hook_mask & (1 << NF_IP_PRE_ROUTING | 1 << NF_IP_LOCAL_IN) + && info->flags & XT_POLICY_MATCH_OUT) { + printk(KERN_ERR "xt_policy: output policy not valid in " + "PRE_ROUTING and INPUT\n"); + return 0; + } + if (hook_mask & (1 << NF_IP_POST_ROUTING | 1 << NF_IP_LOCAL_OUT) + && info->flags & XT_POLICY_MATCH_IN) { + printk(KERN_ERR "xt_policy: input policy not valid in " + "POST_ROUTING and OUTPUT\n"); + return 0; + } + if (info->len > XT_POLICY_MAX_ELEM) { + printk(KERN_ERR "xt_policy: too many policy elements\n"); + return 0; + } + return 1; +} + +static struct xt_match policy_match = { + .name = "policy", + .family = AF_INET, + .match = match, + .matchsize = sizeof(struct xt_policy_info), + .checkentry = checkentry, + .me = THIS_MODULE, +}; + +static struct xt_match policy6_match = { + .name = "policy", + .family = AF_INET6, + .match = match, + .matchsize = sizeof(struct xt_policy_info), + .checkentry = checkentry, + .me = THIS_MODULE, +}; + +static int __init init(void) +{ + int ret; + + ret = xt_register_match(AF_INET, &policy_match); + if (ret) + return ret; + ret = xt_register_match(AF_INET6, &policy6_match); + if (ret) + xt_unregister_match(AF_INET, &policy_match); + return ret; +} + +static void __exit fini(void) +{ + xt_unregister_match(AF_INET6, &policy6_match); + xt_unregister_match(AF_INET, &policy_match); +} + +module_init(init); +module_exit(fini); +MODULE_ALIAS("ipt_policy"); +MODULE_ALIAS("ip6t_policy"); -- 2.39.5