# This is a BitKeeper generated diff -Nru style patch. # # ChangeSet # 2004/03/02 06:08:55+01:00 kaber@trash.net # Add policy match # # net/ipv4/netfilter/ipt_policy.c # 2004/03/02 06:08:46+01:00 kaber@trash.net +176 -0 # # include/linux/netfilter_ipv4/ipt_policy.h # 2004/03/02 06:08:46+01:00 kaber@trash.net +52 -0 # # net/ipv4/netfilter/ipt_policy.c # 2004/03/02 06:08:46+01:00 kaber@trash.net +0 -0 # BitKeeper file /home/kaber/src/nf/ipsec/linux-2.6/net/ipv4/netfilter/ipt_policy.c # # net/ipv4/netfilter/Makefile # 2004/03/02 06:08:46+01:00 kaber@trash.net +1 -0 # Add policy match # # net/ipv4/netfilter/Kconfig # 2004/03/02 06:08:46+01:00 kaber@trash.net +10 -0 # Add policy match # # include/linux/netfilter_ipv4/ipt_policy.h # 2004/03/02 06:08:46+01:00 kaber@trash.net +0 -0 # BitKeeper file /home/kaber/src/nf/ipsec/linux-2.6/include/linux/netfilter_ipv4/ipt_policy.h # diff -Nru a/include/linux/netfilter_ipv4/ipt_policy.h b/include/linux/netfilter_ipv4/ipt_policy.h --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/include/linux/netfilter_ipv4/ipt_policy.h Tue Mar 2 06:53:14 2004 @@ -0,0 +1,52 @@ +#ifndef _IPT_POLICY_H +#define _IPT_POLICY_H + +#define POLICY_MAX_ELEM 4 + +enum ipt_policy_flags +{ + POLICY_MATCH_IN = 0x1, + POLICY_MATCH_OUT = 0x2, + POLICY_MATCH_NONE = 0x4, + POLICY_MATCH_STRICT = 0x8, +}; + +enum ipt_policy_modes +{ + POLICY_MODE_TRANSPORT, + POLICY_MODE_TUNNEL +}; + +struct ipt_policy_spec +{ + u_int8_t saddr:1, + daddr:1, + proto:1, + mode:1, + spi:1, + reqid:1; +}; + +struct ipt_policy_elem +{ + u_int32_t saddr; + u_int32_t smask; + u_int32_t daddr; + u_int32_t 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[POLICY_MAX_ELEM]; + u_int16_t flags; + u_int16_t len; +}; + +#endif /* _IPT_POLICY_H */ diff -Nru a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig --- a/net/ipv4/netfilter/Kconfig Tue Mar 2 06:53:14 2004 +++ b/net/ipv4/netfilter/Kconfig Tue Mar 2 06:53:14 2004 @@ -127,6 +127,16 @@ To compile it as a module, choose M here. If unsure, say N. +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. + config IP_NF_MATCH_MARK tristate "netfilter MARK match support" depends on IP_NF_IPTABLES diff -Nru a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile --- a/net/ipv4/netfilter/Makefile Tue Mar 2 06:53:14 2004 +++ b/net/ipv4/netfilter/Makefile Tue Mar 2 06:53:14 2004 @@ -65,6 +65,7 @@ obj-$(CONFIG_IP_NF_MATCH_TCPMSS) += ipt_tcpmss.o obj-$(CONFIG_IP_NF_MATCH_PHYSDEV) += ipt_physdev.o +obj-$(CONFIG_IP_NF_MATCH_POLICY) += ipt_policy.o # targets obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o diff -Nru a/net/ipv4/netfilter/ipt_policy.c b/net/ipv4/netfilter/ipt_policy.c --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/net/ipv4/netfilter/ipt_policy.c Tue Mar 2 06:53:14 2004 @@ -0,0 +1,176 @@ +/* IP tables module for matching IPsec policy + * + * Copyright (c) 2004 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 MISMATCH(x,y) (e->match.x && ((e->x != (y)) ^ e->invert.x)) + + if (MISMATCH(saddr, x->props.saddr.a4 & e->smask) || + MISMATCH(daddr, x->id.daddr.a4 & e->dmask) || + MISMATCH(proto, x->id.proto) || + MISMATCH(mode, x->props.mode) || + MISMATCH(spi, x->id.spi) || + MISMATCH(reqid, x->props.reqid)) + return 0; + return 1; +} + +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 & 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 & 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 ? 1 : 0; +} + +static int match(const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const void *matchinfo, int offset, int *hotdrop) +{ + const struct ipt_policy_info *info = matchinfo; + int ret; + + if (info->flags & POLICY_MATCH_IN) + ret = match_policy_in(skb, info); + else + ret = match_policy_out(skb, info); + + if (ret < 0) { + if (info->flags & POLICY_MATCH_NONE) + ret = 1; + else + ret = 0; + } else if (info->flags & POLICY_MATCH_NONE) + ret = 0; + + return ret; +} + +static int checkentry(const char *tablename, const struct ipt_ip *ip, + void *matchinfo, unsigned int matchsize, + unsigned int hook_mask) +{ + struct ipt_policy_info *info = matchinfo; + + if (matchsize != IPT_ALIGN(sizeof(*info))) { + printk(KERN_ERR "ipt_policy: matchsize %u != %u\n", + matchsize, IPT_ALIGN(sizeof(*info))); + return 0; + } + if (!(info->flags & (POLICY_MATCH_IN|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 & 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 & POLICY_MATCH_IN) { + printk(KERN_ERR "ipt_policy: input policy not valid in " + "POST_ROUTING and OUTPUT\n"); + return 0; + } + if (info->len > 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, + .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);