From 2a5538e9aa4929329813bee69922c9ae4990fcad Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 25 Aug 2014 12:05:27 +0200 Subject: netfilter: nat: move specific NAT IPv6 to core Move the specific NAT IPv6 core functions that are called from the hooks from ip6table_nat.c to nf_nat_l3proto_ipv6.c. This prepares the ground to allow iptables and nft to use the same NAT engine code that comes in a follow up patch. This also renames nf_nat_ipv6_fn to nft_nat_ipv6_fn in net/ipv6/netfilter/nft_chain_nat_ipv6.c to avoid a compilation breakage. Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/ip6table_nat.c | 233 +++++-------------------------- net/ipv6/netfilter/nf_nat_l3proto_ipv6.c | 199 ++++++++++++++++++++++++++ net/ipv6/netfilter/nft_chain_nat_ipv6.c | 10 +- 3 files changed, 238 insertions(+), 204 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/netfilter/ip6table_nat.c b/net/ipv6/netfilter/ip6table_nat.c index 387d8b8..b0634ac 100644 --- a/net/ipv6/netfilter/ip6table_nat.c +++ b/net/ipv6/netfilter/ip6table_nat.c @@ -30,222 +30,57 @@ static const struct xt_table nf_nat_ipv6_table = { .af = NFPROTO_IPV6, }; -static unsigned int alloc_null_binding(struct nf_conn *ct, unsigned int hooknum) -{ - /* Force range to this IP; let proto decide mapping for - * per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED). - */ - struct nf_nat_range range; - - range.flags = 0; - pr_debug("Allocating NULL binding for %p (%pI6)\n", ct, - HOOK2MANIP(hooknum) == NF_NAT_MANIP_SRC ? - &ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip6 : - &ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip6); - - return nf_nat_setup_info(ct, &range, HOOK2MANIP(hooknum)); -} - -static unsigned int nf_nat_rule_find(struct sk_buff *skb, unsigned int hooknum, - const struct net_device *in, - const struct net_device *out, - struct nf_conn *ct) +static unsigned int ip6table_nat_do_chain(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + struct nf_conn *ct) { struct net *net = nf_ct_net(ct); - unsigned int ret; - ret = ip6t_do_table(skb, hooknum, in, out, net->ipv6.ip6table_nat); - if (ret == NF_ACCEPT) { - if (!nf_nat_initialized(ct, HOOK2MANIP(hooknum))) - ret = alloc_null_binding(ct, hooknum); - } - return ret; + return ip6t_do_table(skb, ops->hooknum, in, out, net->ipv6.ip6table_nat); } -static unsigned int -nf_nat_ipv6_fn(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int ip6table_nat_fn(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) { - struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - struct nf_conn_nat *nat; - enum nf_nat_manip_type maniptype = HOOK2MANIP(ops->hooknum); - __be16 frag_off; - int hdrlen; - u8 nexthdr; - - ct = nf_ct_get(skb, &ctinfo); - /* Can't track? It's not due to stress, or conntrack would - * have dropped it. Hence it's the user's responsibilty to - * packet filter it out, or implement conntrack/NAT for that - * protocol. 8) --RR - */ - if (!ct) - return NF_ACCEPT; - - /* Don't try to NAT if this packet is not conntracked */ - if (nf_ct_is_untracked(ct)) - return NF_ACCEPT; - - nat = nf_ct_nat_ext_add(ct); - if (nat == NULL) - return NF_ACCEPT; - - switch (ctinfo) { - case IP_CT_RELATED: - case IP_CT_RELATED_REPLY: - nexthdr = ipv6_hdr(skb)->nexthdr; - hdrlen = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), - &nexthdr, &frag_off); - - if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) { - if (!nf_nat_icmpv6_reply_translation(skb, ct, ctinfo, - ops->hooknum, - hdrlen)) - return NF_DROP; - else - return NF_ACCEPT; - } - /* Fall thru... (Only ICMPs can be IP_CT_IS_REPLY) */ - case IP_CT_NEW: - /* Seen it before? This can happen for loopback, retrans, - * or local packets. - */ - if (!nf_nat_initialized(ct, maniptype)) { - unsigned int ret; - - ret = nf_nat_rule_find(skb, ops->hooknum, in, out, ct); - if (ret != NF_ACCEPT) - return ret; - } else { - pr_debug("Already setup manip %s for ct %p\n", - maniptype == NF_NAT_MANIP_SRC ? "SRC" : "DST", - ct); - if (nf_nat_oif_changed(ops->hooknum, ctinfo, nat, out)) - goto oif_changed; - } - break; - - default: - /* ESTABLISHED */ - NF_CT_ASSERT(ctinfo == IP_CT_ESTABLISHED || - ctinfo == IP_CT_ESTABLISHED_REPLY); - if (nf_nat_oif_changed(ops->hooknum, ctinfo, nat, out)) - goto oif_changed; - } - - return nf_nat_packet(ct, ctinfo, ops->hooknum, skb); - -oif_changed: - nf_ct_kill_acct(ct, ctinfo, skb); - return NF_DROP; + return nf_nat_ipv6_fn(ops, skb, in, out, ip6table_nat_do_chain); } -static unsigned int -nf_nat_ipv6_in(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int ip6table_nat_in(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) { - unsigned int ret; - struct in6_addr daddr = ipv6_hdr(skb)->daddr; - - ret = nf_nat_ipv6_fn(ops, skb, in, out, okfn); - if (ret != NF_DROP && ret != NF_STOLEN && - ipv6_addr_cmp(&daddr, &ipv6_hdr(skb)->daddr)) - skb_dst_drop(skb); - - return ret; + return nf_nat_ipv6_in(ops, skb, in, out, ip6table_nat_do_chain); } -static unsigned int -nf_nat_ipv6_out(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int ip6table_nat_out(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) { -#ifdef CONFIG_XFRM - const struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - int err; -#endif - unsigned int ret; - - /* root is playing with raw sockets. */ - if (skb->len < sizeof(struct ipv6hdr)) - return NF_ACCEPT; - - ret = nf_nat_ipv6_fn(ops, skb, in, out, okfn); -#ifdef CONFIG_XFRM - if (ret != NF_DROP && ret != NF_STOLEN && - !(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && - (ct = nf_ct_get(skb, &ctinfo)) != NULL) { - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - - if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, - &ct->tuplehash[!dir].tuple.dst.u3) || - (ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMPV6 && - ct->tuplehash[dir].tuple.src.u.all != - ct->tuplehash[!dir].tuple.dst.u.all)) { - err = nf_xfrm_me_harder(skb, AF_INET6); - if (err < 0) - ret = NF_DROP_ERR(err); - } - } -#endif - return ret; + return nf_nat_ipv6_out(ops, skb, in, out, ip6table_nat_do_chain); } -static unsigned int -nf_nat_ipv6_local_fn(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int ip6table_nat_local_fn(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) { - const struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - unsigned int ret; - int err; - - /* root is playing with raw sockets. */ - if (skb->len < sizeof(struct ipv6hdr)) - return NF_ACCEPT; - - ret = nf_nat_ipv6_fn(ops, skb, in, out, okfn); - if (ret != NF_DROP && ret != NF_STOLEN && - (ct = nf_ct_get(skb, &ctinfo)) != NULL) { - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - - if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, - &ct->tuplehash[!dir].tuple.src.u3)) { - err = ip6_route_me_harder(skb); - if (err < 0) - ret = NF_DROP_ERR(err); - } -#ifdef CONFIG_XFRM - else if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && - ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMPV6 && - ct->tuplehash[dir].tuple.dst.u.all != - ct->tuplehash[!dir].tuple.src.u.all) { - err = nf_xfrm_me_harder(skb, AF_INET6); - if (err < 0) - ret = NF_DROP_ERR(err); - } -#endif - } - return ret; + return nf_nat_ipv6_local_fn(ops, skb, in, out, ip6table_nat_do_chain); } static struct nf_hook_ops nf_nat_ipv6_ops[] __read_mostly = { /* Before packet filtering, change destination */ { - .hook = nf_nat_ipv6_in, + .hook = ip6table_nat_in, .owner = THIS_MODULE, .pf = NFPROTO_IPV6, .hooknum = NF_INET_PRE_ROUTING, @@ -253,7 +88,7 @@ static struct nf_hook_ops nf_nat_ipv6_ops[] __read_mostly = { }, /* After packet filtering, change source */ { - .hook = nf_nat_ipv6_out, + .hook = ip6table_nat_out, .owner = THIS_MODULE, .pf = NFPROTO_IPV6, .hooknum = NF_INET_POST_ROUTING, @@ -261,7 +96,7 @@ static struct nf_hook_ops nf_nat_ipv6_ops[] __read_mostly = { }, /* Before packet filtering, change destination */ { - .hook = nf_nat_ipv6_local_fn, + .hook = ip6table_nat_local_fn, .owner = THIS_MODULE, .pf = NFPROTO_IPV6, .hooknum = NF_INET_LOCAL_OUT, @@ -269,7 +104,7 @@ static struct nf_hook_ops nf_nat_ipv6_ops[] __read_mostly = { }, /* After packet filtering, change source */ { - .hook = nf_nat_ipv6_fn, + .hook = ip6table_nat_fn, .owner = THIS_MODULE, .pf = NFPROTO_IPV6, .hooknum = NF_INET_LOCAL_IN, diff --git a/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c b/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c index fc8e49b..c5812e1 100644 --- a/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c +++ b/net/ipv6/netfilter/nf_nat_l3proto_ipv6.c @@ -261,6 +261,205 @@ int nf_nat_icmpv6_reply_translation(struct sk_buff *skb, } EXPORT_SYMBOL_GPL(nf_nat_icmpv6_reply_translation); +unsigned int +nf_nat_ipv6_fn(const struct nf_hook_ops *ops, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + unsigned int (*do_chain)(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + struct nf_conn *ct)) +{ + struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + struct nf_conn_nat *nat; + enum nf_nat_manip_type maniptype = HOOK2MANIP(ops->hooknum); + __be16 frag_off; + int hdrlen; + u8 nexthdr; + + ct = nf_ct_get(skb, &ctinfo); + /* Can't track? It's not due to stress, or conntrack would + * have dropped it. Hence it's the user's responsibilty to + * packet filter it out, or implement conntrack/NAT for that + * protocol. 8) --RR + */ + if (!ct) + return NF_ACCEPT; + + /* Don't try to NAT if this packet is not conntracked */ + if (nf_ct_is_untracked(ct)) + return NF_ACCEPT; + + nat = nf_ct_nat_ext_add(ct); + if (nat == NULL) + return NF_ACCEPT; + + switch (ctinfo) { + case IP_CT_RELATED: + case IP_CT_RELATED_REPLY: + nexthdr = ipv6_hdr(skb)->nexthdr; + hdrlen = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), + &nexthdr, &frag_off); + + if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) { + if (!nf_nat_icmpv6_reply_translation(skb, ct, ctinfo, + ops->hooknum, + hdrlen)) + return NF_DROP; + else + return NF_ACCEPT; + } + /* Fall thru... (Only ICMPs can be IP_CT_IS_REPLY) */ + case IP_CT_NEW: + /* Seen it before? This can happen for loopback, retrans, + * or local packets. + */ + if (!nf_nat_initialized(ct, maniptype)) { + unsigned int ret; + + ret = do_chain(ops, skb, in, out, ct); + if (ret != NF_ACCEPT) + return ret; + + if (nf_nat_initialized(ct, HOOK2MANIP(ops->hooknum))) + break; + + ret = nf_nat_alloc_null_binding(ct, ops->hooknum); + if (ret != NF_ACCEPT) + return ret; + } else { + pr_debug("Already setup manip %s for ct %p\n", + maniptype == NF_NAT_MANIP_SRC ? "SRC" : "DST", + ct); + if (nf_nat_oif_changed(ops->hooknum, ctinfo, nat, out)) + goto oif_changed; + } + break; + + default: + /* ESTABLISHED */ + NF_CT_ASSERT(ctinfo == IP_CT_ESTABLISHED || + ctinfo == IP_CT_ESTABLISHED_REPLY); + if (nf_nat_oif_changed(ops->hooknum, ctinfo, nat, out)) + goto oif_changed; + } + + return nf_nat_packet(ct, ctinfo, ops->hooknum, skb); + +oif_changed: + nf_ct_kill_acct(ct, ctinfo, skb); + return NF_DROP; +} +EXPORT_SYMBOL_GPL(nf_nat_ipv6_fn); + +unsigned int +nf_nat_ipv6_in(const struct nf_hook_ops *ops, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + unsigned int (*do_chain)(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + struct nf_conn *ct)) +{ + unsigned int ret; + struct in6_addr daddr = ipv6_hdr(skb)->daddr; + + ret = nf_nat_ipv6_fn(ops, skb, in, out, do_chain); + if (ret != NF_DROP && ret != NF_STOLEN && + ipv6_addr_cmp(&daddr, &ipv6_hdr(skb)->daddr)) + skb_dst_drop(skb); + + return ret; +} +EXPORT_SYMBOL_GPL(nf_nat_ipv6_in); + +unsigned int +nf_nat_ipv6_out(const struct nf_hook_ops *ops, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + unsigned int (*do_chain)(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + struct nf_conn *ct)) +{ +#ifdef CONFIG_XFRM + const struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + int err; +#endif + unsigned int ret; + + /* root is playing with raw sockets. */ + if (skb->len < sizeof(struct ipv6hdr)) + return NF_ACCEPT; + + ret = nf_nat_ipv6_fn(ops, skb, in, out, do_chain); +#ifdef CONFIG_XFRM + if (ret != NF_DROP && ret != NF_STOLEN && + !(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && + (ct = nf_ct_get(skb, &ctinfo)) != NULL) { + enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + + if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, + &ct->tuplehash[!dir].tuple.dst.u3) || + (ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMPV6 && + ct->tuplehash[dir].tuple.src.u.all != + ct->tuplehash[!dir].tuple.dst.u.all)) { + err = nf_xfrm_me_harder(skb, AF_INET6); + if (err < 0) + ret = NF_DROP_ERR(err); + } + } +#endif + return ret; +} +EXPORT_SYMBOL_GPL(nf_nat_ipv6_out); + +unsigned int +nf_nat_ipv6_local_fn(const struct nf_hook_ops *ops, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + unsigned int (*do_chain)(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + struct nf_conn *ct)) +{ + const struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + unsigned int ret; + int err; + + /* root is playing with raw sockets. */ + if (skb->len < sizeof(struct ipv6hdr)) + return NF_ACCEPT; + + ret = nf_nat_ipv6_fn(ops, skb, in, out, do_chain); + if (ret != NF_DROP && ret != NF_STOLEN && + (ct = nf_ct_get(skb, &ctinfo)) != NULL) { + enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + + if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, + &ct->tuplehash[!dir].tuple.src.u3)) { + err = ip6_route_me_harder(skb); + if (err < 0) + ret = NF_DROP_ERR(err); + } +#ifdef CONFIG_XFRM + else if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && + ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMPV6 && + ct->tuplehash[dir].tuple.dst.u.all != + ct->tuplehash[!dir].tuple.src.u.all) { + err = nf_xfrm_me_harder(skb, AF_INET6); + if (err < 0) + ret = NF_DROP_ERR(err); + } +#endif + } + return ret; +} +EXPORT_SYMBOL_GPL(nf_nat_ipv6_local_fn); + static int __init nf_nat_l3proto_ipv6_init(void) { int err; diff --git a/net/ipv6/netfilter/nft_chain_nat_ipv6.c b/net/ipv6/netfilter/nft_chain_nat_ipv6.c index d189fcb..c1c7449 100644 --- a/net/ipv6/netfilter/nft_chain_nat_ipv6.c +++ b/net/ipv6/netfilter/nft_chain_nat_ipv6.c @@ -28,7 +28,7 @@ * IPv6 NAT chains */ -static unsigned int nf_nat_ipv6_fn(const struct nf_hook_ops *ops, +static unsigned int nft_nat_ipv6_fn(const struct nf_hook_ops *ops, struct sk_buff *skb, const struct net_device *in, const struct net_device *out, @@ -97,7 +97,7 @@ static unsigned int nf_nat_ipv6_prerouting(const struct nf_hook_ops *ops, struct in6_addr daddr = ipv6_hdr(skb)->daddr; unsigned int ret; - ret = nf_nat_ipv6_fn(ops, skb, in, out, okfn); + ret = nft_nat_ipv6_fn(ops, skb, in, out, okfn); if (ret != NF_DROP && ret != NF_STOLEN && ipv6_addr_cmp(&daddr, &ipv6_hdr(skb)->daddr)) skb_dst_drop(skb); @@ -115,7 +115,7 @@ static unsigned int nf_nat_ipv6_postrouting(const struct nf_hook_ops *ops, const struct nf_conn *ct __maybe_unused; unsigned int ret; - ret = nf_nat_ipv6_fn(ops, skb, in, out, okfn); + ret = nft_nat_ipv6_fn(ops, skb, in, out, okfn); #ifdef CONFIG_XFRM if (ret != NF_DROP && ret != NF_STOLEN && !(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && @@ -143,7 +143,7 @@ static unsigned int nf_nat_ipv6_output(const struct nf_hook_ops *ops, const struct nf_conn *ct; unsigned int ret; - ret = nf_nat_ipv6_fn(ops, skb, in, out, okfn); + ret = nft_nat_ipv6_fn(ops, skb, in, out, okfn); if (ret != NF_DROP && ret != NF_STOLEN && (ct = nf_ct_get(skb, &ctinfo)) != NULL) { enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); @@ -177,7 +177,7 @@ static const struct nf_chain_type nft_chain_nat_ipv6 = { [NF_INET_PRE_ROUTING] = nf_nat_ipv6_prerouting, [NF_INET_POST_ROUTING] = nf_nat_ipv6_postrouting, [NF_INET_LOCAL_OUT] = nf_nat_ipv6_output, - [NF_INET_LOCAL_IN] = nf_nat_ipv6_fn, + [NF_INET_LOCAL_IN] = nft_nat_ipv6_fn, }, }; -- cgit v1.1 From 876665eafc0e43523d0c57b5c937b59696fb4a8f Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 9 Sep 2014 16:31:09 +0200 Subject: netfilter: nft_chain_nat_ipv6: use generic IPv6 NAT code from core Use the exported IPv6 NAT functions that are provided by the core. This removes duplicated code so iptables and nft use the same NAT codebase. Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/nft_chain_nat_ipv6.c | 163 +++++++------------------------- 1 file changed, 36 insertions(+), 127 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/netfilter/nft_chain_nat_ipv6.c b/net/ipv6/netfilter/nft_chain_nat_ipv6.c index c1c7449..1c4b75d 100644 --- a/net/ipv6/netfilter/nft_chain_nat_ipv6.c +++ b/net/ipv6/netfilter/nft_chain_nat_ipv6.c @@ -24,144 +24,53 @@ #include #include -/* - * IPv6 NAT chains - */ - -static unsigned int nft_nat_ipv6_fn(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int nft_nat_do_chain(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + struct nf_conn *ct) { - enum ip_conntrack_info ctinfo; - struct nf_conn *ct = nf_ct_get(skb, &ctinfo); - struct nf_conn_nat *nat; - enum nf_nat_manip_type maniptype = HOOK2MANIP(ops->hooknum); - __be16 frag_off; - int hdrlen; - u8 nexthdr; struct nft_pktinfo pkt; - unsigned int ret; - - if (ct == NULL || nf_ct_is_untracked(ct)) - return NF_ACCEPT; - - nat = nf_ct_nat_ext_add(ct); - if (nat == NULL) - return NF_ACCEPT; - - switch (ctinfo) { - case IP_CT_RELATED: - case IP_CT_RELATED + IP_CT_IS_REPLY: - nexthdr = ipv6_hdr(skb)->nexthdr; - hdrlen = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), - &nexthdr, &frag_off); - - if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) { - if (!nf_nat_icmpv6_reply_translation(skb, ct, ctinfo, - ops->hooknum, - hdrlen)) - return NF_DROP; - else - return NF_ACCEPT; - } - /* Fall through */ - case IP_CT_NEW: - if (nf_nat_initialized(ct, maniptype)) - break; - - nft_set_pktinfo_ipv6(&pkt, ops, skb, in, out); - ret = nft_do_chain(&pkt, ops); - if (ret != NF_ACCEPT) - return ret; - if (!nf_nat_initialized(ct, maniptype)) { - ret = nf_nat_alloc_null_binding(ct, ops->hooknum); - if (ret != NF_ACCEPT) - return ret; - } - default: - break; - } + nft_set_pktinfo_ipv6(&pkt, ops, skb, in, out); - return nf_nat_packet(ct, ctinfo, ops->hooknum, skb); + return nft_do_chain(&pkt, ops); } -static unsigned int nf_nat_ipv6_prerouting(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int nft_nat_ipv6_fn(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) { - struct in6_addr daddr = ipv6_hdr(skb)->daddr; - unsigned int ret; - - ret = nft_nat_ipv6_fn(ops, skb, in, out, okfn); - if (ret != NF_DROP && ret != NF_STOLEN && - ipv6_addr_cmp(&daddr, &ipv6_hdr(skb)->daddr)) - skb_dst_drop(skb); - - return ret; + return nf_nat_ipv6_fn(ops, skb, in, out, nft_nat_do_chain); } -static unsigned int nf_nat_ipv6_postrouting(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int nft_nat_ipv6_in(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) { - enum ip_conntrack_info ctinfo __maybe_unused; - const struct nf_conn *ct __maybe_unused; - unsigned int ret; - - ret = nft_nat_ipv6_fn(ops, skb, in, out, okfn); -#ifdef CONFIG_XFRM - if (ret != NF_DROP && ret != NF_STOLEN && - !(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && - (ct = nf_ct_get(skb, &ctinfo)) != NULL) { - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - - if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, - &ct->tuplehash[!dir].tuple.dst.u3) || - (ct->tuplehash[dir].tuple.src.u.all != - ct->tuplehash[!dir].tuple.dst.u.all)) - if (nf_xfrm_me_harder(skb, AF_INET6) < 0) - ret = NF_DROP; - } -#endif - return ret; + return nf_nat_ipv6_in(ops, skb, in, out, nft_nat_do_chain); } -static unsigned int nf_nat_ipv6_output(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int nft_nat_ipv6_out(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) { - enum ip_conntrack_info ctinfo; - const struct nf_conn *ct; - unsigned int ret; - - ret = nft_nat_ipv6_fn(ops, skb, in, out, okfn); - if (ret != NF_DROP && ret != NF_STOLEN && - (ct = nf_ct_get(skb, &ctinfo)) != NULL) { - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + return nf_nat_ipv6_out(ops, skb, in, out, nft_nat_do_chain); +} - if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, - &ct->tuplehash[!dir].tuple.src.u3)) { - if (ip6_route_me_harder(skb)) - ret = NF_DROP; - } -#ifdef CONFIG_XFRM - else if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && - ct->tuplehash[dir].tuple.dst.u.all != - ct->tuplehash[!dir].tuple.src.u.all) - if (nf_xfrm_me_harder(skb, AF_INET6)) - ret = NF_DROP; -#endif - } - return ret; +static unsigned int nft_nat_ipv6_local_fn(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + return nf_nat_ipv6_local_fn(ops, skb, in, out, nft_nat_do_chain); } static const struct nf_chain_type nft_chain_nat_ipv6 = { @@ -174,9 +83,9 @@ static const struct nf_chain_type nft_chain_nat_ipv6 = { (1 << NF_INET_LOCAL_OUT) | (1 << NF_INET_LOCAL_IN), .hooks = { - [NF_INET_PRE_ROUTING] = nf_nat_ipv6_prerouting, - [NF_INET_POST_ROUTING] = nf_nat_ipv6_postrouting, - [NF_INET_LOCAL_OUT] = nf_nat_ipv6_output, + [NF_INET_PRE_ROUTING] = nft_nat_ipv6_in, + [NF_INET_POST_ROUTING] = nft_nat_ipv6_out, + [NF_INET_LOCAL_OUT] = nft_nat_ipv6_local_fn, [NF_INET_LOCAL_IN] = nft_nat_ipv6_fn, }, }; -- cgit v1.1 From be6b635cd674add9410efa9ac6f03e0040848b12 Mon Sep 17 00:00:00 2001 From: Arturo Borrero Date: Thu, 4 Sep 2014 14:06:49 +0200 Subject: netfilter: nf_nat: generalize IPv6 masquerading support for nf_tables Let's refactor the code so we can reach the masquerade functionality from outside the xt context (ie. nftables). The patch includes the addition of an atomic counter to the masquerade notifier: the stuff to be done by the notifier is the same for xt and nftables. Therefore, only one notification handler is needed. This factorization only involves IPv6; a similar patch exists to handle IPv4. Signed-off-by: Arturo Borrero Gonzalez Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/Kconfig | 7 ++ net/ipv6/netfilter/Makefile | 1 + net/ipv6/netfilter/ip6t_MASQUERADE.c | 76 ++---------------- net/ipv6/netfilter/nf_nat_masquerade_ipv6.c | 120 ++++++++++++++++++++++++++++ 4 files changed, 133 insertions(+), 71 deletions(-) create mode 100644 net/ipv6/netfilter/nf_nat_masquerade_ipv6.c (limited to 'net/ipv6') diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig index ac93df1..6c8cfec 100644 --- a/net/ipv6/netfilter/Kconfig +++ b/net/ipv6/netfilter/Kconfig @@ -246,8 +246,15 @@ config NF_NAT_IPV6 if NF_NAT_IPV6 +config NF_NAT_MASQUERADE_IPV6 + tristate "IPv6 masquerade support" + help + This is the kernel functionality to provide NAT in the masquerade + flavour (automatic source address selection) for IPv6. + config IP6_NF_TARGET_MASQUERADE tristate "MASQUERADE target support" + select NF_NAT_MASQUERADE_IPV6 help Masquerading is a special case of NAT: all outgoing connections are changed to seem to come from a particular interface's address, and diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile index c0b2631..89a0bd7 100644 --- a/net/ipv6/netfilter/Makefile +++ b/net/ipv6/netfilter/Makefile @@ -18,6 +18,7 @@ obj-$(CONFIG_NF_CONNTRACK_IPV6) += nf_conntrack_ipv6.o nf_nat_ipv6-y := nf_nat_l3proto_ipv6.o nf_nat_proto_icmpv6.o obj-$(CONFIG_NF_NAT_IPV6) += nf_nat_ipv6.o +obj-$(CONFIG_NF_NAT_MASQUERADE_IPV6) += nf_nat_masquerade_ipv6.o # defrag nf_defrag_ipv6-y := nf_defrag_ipv6_hooks.o nf_conntrack_reasm.o diff --git a/net/ipv6/netfilter/ip6t_MASQUERADE.c b/net/ipv6/netfilter/ip6t_MASQUERADE.c index 3e4e92d..7f9f45d 100644 --- a/net/ipv6/netfilter/ip6t_MASQUERADE.c +++ b/net/ipv6/netfilter/ip6t_MASQUERADE.c @@ -19,33 +19,12 @@ #include #include #include +#include static unsigned int masquerade_tg6(struct sk_buff *skb, const struct xt_action_param *par) { - const struct nf_nat_range *range = par->targinfo; - enum ip_conntrack_info ctinfo; - struct in6_addr src; - struct nf_conn *ct; - struct nf_nat_range newrange; - - ct = nf_ct_get(skb, &ctinfo); - NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED || - ctinfo == IP_CT_RELATED_REPLY)); - - if (ipv6_dev_get_saddr(dev_net(par->out), par->out, - &ipv6_hdr(skb)->daddr, 0, &src) < 0) - return NF_DROP; - - nfct_nat(ct)->masq_index = par->out->ifindex; - - newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS; - newrange.min_addr.in6 = src; - newrange.max_addr.in6 = src; - newrange.min_proto = range->min_proto; - newrange.max_proto = range->max_proto; - - return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_SRC); + return nf_nat_masquerade_ipv6(skb, par->targinfo, par->out); } static int masquerade_tg6_checkentry(const struct xt_tgchk_param *par) @@ -57,48 +36,6 @@ static int masquerade_tg6_checkentry(const struct xt_tgchk_param *par) return 0; } -static int device_cmp(struct nf_conn *ct, void *ifindex) -{ - const struct nf_conn_nat *nat = nfct_nat(ct); - - if (!nat) - return 0; - if (nf_ct_l3num(ct) != NFPROTO_IPV6) - return 0; - return nat->masq_index == (int)(long)ifindex; -} - -static int masq_device_event(struct notifier_block *this, - unsigned long event, void *ptr) -{ - const struct net_device *dev = netdev_notifier_info_to_dev(ptr); - struct net *net = dev_net(dev); - - if (event == NETDEV_DOWN) - nf_ct_iterate_cleanup(net, device_cmp, - (void *)(long)dev->ifindex, 0, 0); - - return NOTIFY_DONE; -} - -static struct notifier_block masq_dev_notifier = { - .notifier_call = masq_device_event, -}; - -static int masq_inet_event(struct notifier_block *this, - unsigned long event, void *ptr) -{ - struct inet6_ifaddr *ifa = ptr; - struct netdev_notifier_info info; - - netdev_notifier_info_init(&info, ifa->idev->dev); - return masq_device_event(this, event, &info); -} - -static struct notifier_block masq_inet_notifier = { - .notifier_call = masq_inet_event, -}; - static struct xt_target masquerade_tg6_reg __read_mostly = { .name = "MASQUERADE", .family = NFPROTO_IPV6, @@ -115,17 +52,14 @@ static int __init masquerade_tg6_init(void) int err; err = xt_register_target(&masquerade_tg6_reg); - if (err == 0) { - register_netdevice_notifier(&masq_dev_notifier); - register_inet6addr_notifier(&masq_inet_notifier); - } + if (err == 0) + nf_nat_masquerade_ipv6_register_notifier(); return err; } static void __exit masquerade_tg6_exit(void) { - unregister_inet6addr_notifier(&masq_inet_notifier); - unregister_netdevice_notifier(&masq_dev_notifier); + nf_nat_masquerade_ipv6_unregister_notifier(); xt_unregister_target(&masquerade_tg6_reg); } diff --git a/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c b/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c new file mode 100644 index 0000000..7745609 --- /dev/null +++ b/net/ipv6/netfilter/nf_nat_masquerade_ipv6.c @@ -0,0 +1,120 @@ +/* + * Copyright (c) 2011 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. + * + * Based on Rusty Russell's IPv6 MASQUERADE target. Development of IPv6 + * NAT funded by Astaro. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +unsigned int +nf_nat_masquerade_ipv6(struct sk_buff *skb, const struct nf_nat_range *range, + const struct net_device *out) +{ + enum ip_conntrack_info ctinfo; + struct in6_addr src; + struct nf_conn *ct; + struct nf_nat_range newrange; + + ct = nf_ct_get(skb, &ctinfo); + NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED || + ctinfo == IP_CT_RELATED_REPLY)); + + if (ipv6_dev_get_saddr(dev_net(out), out, + &ipv6_hdr(skb)->daddr, 0, &src) < 0) + return NF_DROP; + + nfct_nat(ct)->masq_index = out->ifindex; + + newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS; + newrange.min_addr.in6 = src; + newrange.max_addr.in6 = src; + newrange.min_proto = range->min_proto; + newrange.max_proto = range->max_proto; + + return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_SRC); +} +EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6); + +static int device_cmp(struct nf_conn *ct, void *ifindex) +{ + const struct nf_conn_nat *nat = nfct_nat(ct); + + if (!nat) + return 0; + if (nf_ct_l3num(ct) != NFPROTO_IPV6) + return 0; + return nat->masq_index == (int)(long)ifindex; +} + +static int masq_device_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + const struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct net *net = dev_net(dev); + + if (event == NETDEV_DOWN) + nf_ct_iterate_cleanup(net, device_cmp, + (void *)(long)dev->ifindex, 0, 0); + + return NOTIFY_DONE; +} + +static struct notifier_block masq_dev_notifier = { + .notifier_call = masq_device_event, +}; + +static int masq_inet_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct inet6_ifaddr *ifa = ptr; + struct netdev_notifier_info info; + + netdev_notifier_info_init(&info, ifa->idev->dev); + return masq_device_event(this, event, &info); +} + +static struct notifier_block masq_inet_notifier = { + .notifier_call = masq_inet_event, +}; + +static atomic_t masquerade_notifier_refcount = ATOMIC_INIT(0); + +void nf_nat_masquerade_ipv6_register_notifier(void) +{ + /* check if the notifier is already set */ + if (atomic_inc_return(&masquerade_notifier_refcount) > 1) + return; + + register_netdevice_notifier(&masq_dev_notifier); + register_inet6addr_notifier(&masq_inet_notifier); +} +EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_register_notifier); + +void nf_nat_masquerade_ipv6_unregister_notifier(void) +{ + /* check if the notifier still has clients */ + if (atomic_dec_return(&masquerade_notifier_refcount) > 0) + return; + + unregister_inet6addr_notifier(&masq_inet_notifier); + unregister_netdevice_notifier(&masq_dev_notifier); +} +EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv6_unregister_notifier); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Patrick McHardy "); -- cgit v1.1 From 9ba1f726bec090399eb9bb9157eb32dedc8e8c45 Mon Sep 17 00:00:00 2001 From: Arturo Borrero Date: Mon, 8 Sep 2014 13:45:00 +0200 Subject: netfilter: nf_tables: add new nft_masq expression The nft_masq expression is intended to perform NAT in the masquerade flavour. We decided to have the masquerade functionality in a separated expression other than nft_nat. Signed-off-by: Arturo Borrero Gonzalez Signed-off-by: Pablo Neira Ayuso --- net/ipv6/netfilter/Kconfig | 6 +++ net/ipv6/netfilter/Makefile | 1 + net/ipv6/netfilter/nft_masq_ipv6.c | 89 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 96 insertions(+) create mode 100644 net/ipv6/netfilter/nft_masq_ipv6.c (limited to 'net/ipv6') diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig index 6c8cfec..24c535f 100644 --- a/net/ipv6/netfilter/Kconfig +++ b/net/ipv6/netfilter/Kconfig @@ -252,6 +252,12 @@ config NF_NAT_MASQUERADE_IPV6 This is the kernel functionality to provide NAT in the masquerade flavour (automatic source address selection) for IPv6. +config NFT_MASQ_IPV6 + tristate "IPv6 masquerade support for nf_tables" + depends on NF_TABLES_IPV6 + depends on NFT_MASQ + select NF_NAT_MASQUERADE_IPV6 + config IP6_NF_TARGET_MASQUERADE tristate "MASQUERADE target support" select NF_NAT_MASQUERADE_IPV6 diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile index 89a0bd7..482c4df 100644 --- a/net/ipv6/netfilter/Makefile +++ b/net/ipv6/netfilter/Makefile @@ -32,6 +32,7 @@ obj-$(CONFIG_NF_TABLES_IPV6) += nf_tables_ipv6.o obj-$(CONFIG_NFT_CHAIN_ROUTE_IPV6) += nft_chain_route_ipv6.o obj-$(CONFIG_NFT_CHAIN_NAT_IPV6) += nft_chain_nat_ipv6.o obj-$(CONFIG_NFT_REJECT_IPV6) += nft_reject_ipv6.o +obj-$(CONFIG_NFT_MASQ_IPV6) += nft_masq_ipv6.o # matches obj-$(CONFIG_IP6_NF_MATCH_AH) += ip6t_ah.o diff --git a/net/ipv6/netfilter/nft_masq_ipv6.c b/net/ipv6/netfilter/nft_masq_ipv6.c new file mode 100644 index 0000000..4e51334 --- /dev/null +++ b/net/ipv6/netfilter/nft_masq_ipv6.c @@ -0,0 +1,89 @@ +/* + * Copyright (c) 2014 Arturo Borrero Gonzalez + * + * 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 +#include + +static void nft_masq_ipv6_eval(const struct nft_expr *expr, + struct nft_data data[NFT_REG_MAX + 1], + const struct nft_pktinfo *pkt) +{ + struct nft_masq *priv = nft_expr_priv(expr); + struct nf_nat_range range; + unsigned int verdict; + + range.flags = priv->flags; + + verdict = nf_nat_masquerade_ipv6(pkt->skb, &range, pkt->out); + + data[NFT_REG_VERDICT].verdict = verdict; +} + +static int nft_masq_ipv6_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + int err; + + err = nft_masq_init(ctx, expr, tb); + if (err < 0) + return err; + + nf_nat_masquerade_ipv6_register_notifier(); + return 0; +} + +static void nft_masq_ipv6_destroy(const struct nft_ctx *ctx, + const struct nft_expr *expr) +{ + nf_nat_masquerade_ipv6_unregister_notifier(); +} + +static struct nft_expr_type nft_masq_ipv6_type; +static const struct nft_expr_ops nft_masq_ipv6_ops = { + .type = &nft_masq_ipv6_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_masq)), + .eval = nft_masq_ipv6_eval, + .init = nft_masq_ipv6_init, + .destroy = nft_masq_ipv6_destroy, + .dump = nft_masq_dump, +}; + +static struct nft_expr_type nft_masq_ipv6_type __read_mostly = { + .family = NFPROTO_IPV6, + .name = "masq", + .ops = &nft_masq_ipv6_ops, + .policy = nft_masq_policy, + .maxattr = NFTA_MASQ_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_masq_ipv6_module_init(void) +{ + return nft_register_expr(&nft_masq_ipv6_type); +} + +static void __exit nft_masq_ipv6_module_exit(void) +{ + nft_unregister_expr(&nft_masq_ipv6_type); +} + +module_init(nft_masq_ipv6_module_init); +module_exit(nft_masq_ipv6_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Arturo Borrero Gonzalez "); +MODULE_ALIAS_NFT_AF_EXPR(AF_INET6, "masq"); -- cgit v1.1