diff options
author | Florian Westphal <fw@strlen.de> | 2019-02-19 17:38:21 +0100 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2019-02-27 10:49:55 +0100 |
commit | 3bf195ae6037e310d693ff3313401cfaf1261b71 (patch) | |
tree | 78720e9f22c90e768dc284a17a394fcce904d546 /net/ipv4/netfilter | |
parent | 096d09067a67702f9802e5b3a0fc2ea9c22f1cf6 (diff) | |
download | linux-3bf195ae6037e310d693ff3313401cfaf1261b71.tar.gz linux-3bf195ae6037e310d693ff3313401cfaf1261b71.tar.bz2 linux-3bf195ae6037e310d693ff3313401cfaf1261b71.zip |
netfilter: nat: merge nf_nat_ipv4,6 into nat core
before:
text data bss dec hex filename
16566 1576 4136 22278 5706 nf_nat.ko
3598 844 0 4442 115a nf_nat_ipv6.ko
3187 844 0 4031 fbf nf_nat_ipv4.ko
after:
text data bss dec hex filename
22948 1612 4136 28696 7018 nf_nat.ko
... with ipv4/v6 nat now provided directly via nf_nat.ko.
Also changes:
ret = nf_nat_ipv4_fn(priv, skb, state);
if (ret != NF_DROP && ret != NF_STOLEN &&
into
if (ret != NF_ACCEPT)
return ret;
everywhere.
The nat hooks never should return anything other than
ACCEPT or DROP (and the latter only in rare error cases).
The original code uses multi-line ANDing including assignment-in-if:
if (ret != NF_DROP && ret != NF_STOLEN &&
!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) &&
(ct = nf_ct_get(skb, &ctinfo)) != NULL) {
I removed this while moving, breaking those in separate conditionals
and moving the assignments into extra lines.
checkpatch still generates some warnings:
1. Overly long lines (of moved code).
Breaking them is even more ugly. so I kept this as-is.
2. use of extern function declarations in a .c file.
This is necessary evil, we must call
nf_nat_l3proto_register() from the nat core now.
All l3proto related functions are removed later in this series,
those prototypes are then removed as well.
v2: keep empty nf_nat_ipv6_csum_update stub for CONFIG_IPV6=n case.
v3: remove IS_ENABLED(NF_NAT_IPV4/6) tests, NF_NAT_IPVx toggles
are removed here.
v4: also get rid of the assignments in conditionals.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/ipv4/netfilter')
-rw-r--r-- | net/ipv4/netfilter/Kconfig | 15 | ||||
-rw-r--r-- | net/ipv4/netfilter/Makefile | 3 | ||||
-rw-r--r-- | net/ipv4/netfilter/nf_nat_l3proto_ipv4.c | 330 |
3 files changed, 2 insertions, 346 deletions
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig index db05a835748a..8688461ed077 100644 --- a/net/ipv4/netfilter/Kconfig +++ b/net/ipv4/netfilter/Kconfig @@ -94,17 +94,7 @@ config NF_REJECT_IPV4 tristate "IPv4 packet rejection" default m if NETFILTER_ADVANCED=n -config NF_NAT_IPV4 - tristate "IPv4 NAT" - depends on NF_CONNTRACK - default m if NETFILTER_ADVANCED=n - select NF_NAT - help - The IPv4 NAT option allows masquerading, port forwarding and other - forms of full Network Address Port Translation. This can be - controlled by iptables or nft. - -if NF_NAT_IPV4 +if NF_NAT if NF_TABLES config NFT_CHAIN_NAT_IPV4 @@ -163,7 +153,7 @@ config NF_NAT_H323 depends on NF_CONNTRACK default NF_CONNTRACK_H323 -endif # NF_NAT_IPV4 +endif # NF_NAT config IP_NF_IPTABLES tristate "IP tables support (required for filtering/masq/NAT)" @@ -260,7 +250,6 @@ config IP_NF_NAT depends on NF_CONNTRACK default m if NETFILTER_ADVANCED=n select NF_NAT - select NF_NAT_IPV4 select NETFILTER_XT_NAT help This enables the `nat' table in iptables. This allows masquerading, diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile index ddeb35ab8bdb..b2cdf705fdf1 100644 --- a/net/ipv4/netfilter/Makefile +++ b/net/ipv4/netfilter/Makefile @@ -3,9 +3,6 @@ # Makefile for the netfilter modules on top of IPv4. # -nf_nat_ipv4-y := nf_nat_l3proto_ipv4.o -obj-$(CONFIG_NF_NAT_IPV4) += nf_nat_ipv4.o - # defrag obj-$(CONFIG_NF_DEFRAG_IPV4) += nf_defrag_ipv4.o diff --git a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c deleted file mode 100644 index 36b4f9659ffa..000000000000 --- a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c +++ /dev/null @@ -1,330 +0,0 @@ -/* - * (C) 1999-2001 Paul `Rusty' Russell - * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> - * (C) 2011 Patrick McHardy <kaber@trash.net> - * - * 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 <linux/types.h> -#include <linux/module.h> -#include <linux/skbuff.h> -#include <linux/ip.h> -#include <linux/icmp.h> -#include <linux/netfilter.h> -#include <linux/netfilter_ipv4.h> -#include <net/secure_seq.h> -#include <net/checksum.h> -#include <net/route.h> -#include <net/ip.h> - -#include <net/netfilter/nf_conntrack_core.h> -#include <net/netfilter/nf_conntrack.h> -#include <net/netfilter/nf_nat_core.h> -#include <net/netfilter/nf_nat_l3proto.h> -#include <net/netfilter/nf_nat_l4proto.h> - -static const struct nf_nat_l3proto nf_nat_l3proto_ipv4; - -static bool nf_nat_ipv4_manip_pkt(struct sk_buff *skb, - unsigned int iphdroff, - const struct nf_conntrack_tuple *target, - enum nf_nat_manip_type maniptype) -{ - struct iphdr *iph; - unsigned int hdroff; - - if (!skb_make_writable(skb, iphdroff + sizeof(*iph))) - return false; - - iph = (void *)skb->data + iphdroff; - hdroff = iphdroff + iph->ihl * 4; - - if (!nf_nat_l4proto_manip_pkt(skb, &nf_nat_l3proto_ipv4, iphdroff, - hdroff, target, maniptype)) - return false; - iph = (void *)skb->data + iphdroff; - - if (maniptype == NF_NAT_MANIP_SRC) { - csum_replace4(&iph->check, iph->saddr, target->src.u3.ip); - iph->saddr = target->src.u3.ip; - } else { - csum_replace4(&iph->check, iph->daddr, target->dst.u3.ip); - iph->daddr = target->dst.u3.ip; - } - return true; -} - -static void nf_nat_ipv4_csum_update(struct sk_buff *skb, - unsigned int iphdroff, __sum16 *check, - const struct nf_conntrack_tuple *t, - enum nf_nat_manip_type maniptype) -{ - struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff); - __be32 oldip, newip; - - if (maniptype == NF_NAT_MANIP_SRC) { - oldip = iph->saddr; - newip = t->src.u3.ip; - } else { - oldip = iph->daddr; - newip = t->dst.u3.ip; - } - inet_proto_csum_replace4(check, skb, oldip, newip, true); -} - -static void nf_nat_ipv4_csum_recalc(struct sk_buff *skb, - u8 proto, void *data, __sum16 *check, - int datalen, int oldlen) -{ - if (skb->ip_summed != CHECKSUM_PARTIAL) { - const struct iphdr *iph = ip_hdr(skb); - - skb->ip_summed = CHECKSUM_PARTIAL; - skb->csum_start = skb_headroom(skb) + skb_network_offset(skb) + - ip_hdrlen(skb); - skb->csum_offset = (void *)check - data; - *check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, datalen, - proto, 0); - } else - inet_proto_csum_replace2(check, skb, - htons(oldlen), htons(datalen), true); -} - -static const struct nf_nat_l3proto nf_nat_l3proto_ipv4 = { - .l3proto = NFPROTO_IPV4, - .manip_pkt = nf_nat_ipv4_manip_pkt, - .csum_update = nf_nat_ipv4_csum_update, - .csum_recalc = nf_nat_ipv4_csum_recalc, -}; - -int nf_nat_icmp_reply_translation(struct sk_buff *skb, - struct nf_conn *ct, - enum ip_conntrack_info ctinfo, - unsigned int hooknum) -{ - struct { - struct icmphdr icmp; - struct iphdr ip; - } *inside; - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - enum nf_nat_manip_type manip = HOOK2MANIP(hooknum); - unsigned int hdrlen = ip_hdrlen(skb); - struct nf_conntrack_tuple target; - unsigned long statusbit; - - WARN_ON(ctinfo != IP_CT_RELATED && ctinfo != IP_CT_RELATED_REPLY); - - if (!skb_make_writable(skb, hdrlen + sizeof(*inside))) - return 0; - if (nf_ip_checksum(skb, hooknum, hdrlen, 0)) - return 0; - - inside = (void *)skb->data + hdrlen; - if (inside->icmp.type == ICMP_REDIRECT) { - if ((ct->status & IPS_NAT_DONE_MASK) != IPS_NAT_DONE_MASK) - return 0; - if (ct->status & IPS_NAT_MASK) - return 0; - } - - if (manip == NF_NAT_MANIP_SRC) - statusbit = IPS_SRC_NAT; - else - statusbit = IPS_DST_NAT; - - /* Invert if this is reply direction */ - if (dir == IP_CT_DIR_REPLY) - statusbit ^= IPS_NAT_MASK; - - if (!(ct->status & statusbit)) - return 1; - - if (!nf_nat_ipv4_manip_pkt(skb, hdrlen + sizeof(inside->icmp), - &ct->tuplehash[!dir].tuple, !manip)) - return 0; - - if (skb->ip_summed != CHECKSUM_PARTIAL) { - /* Reloading "inside" here since manip_pkt may reallocate */ - inside = (void *)skb->data + hdrlen; - inside->icmp.checksum = 0; - inside->icmp.checksum = - csum_fold(skb_checksum(skb, hdrlen, - skb->len - hdrlen, 0)); - } - - /* Change outer to look like the reply to an incoming packet */ - nf_ct_invert_tuple(&target, &ct->tuplehash[!dir].tuple); - target.dst.protonum = IPPROTO_ICMP; - if (!nf_nat_ipv4_manip_pkt(skb, 0, &target, manip)) - return 0; - - return 1; -} -EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation); - -static unsigned int -nf_nat_ipv4_fn(void *priv, struct sk_buff *skb, - const struct nf_hook_state *state) -{ - struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - - ct = nf_ct_get(skb, &ctinfo); - if (!ct) - return NF_ACCEPT; - - if (ctinfo == IP_CT_RELATED || ctinfo == IP_CT_RELATED_REPLY) { - if (ip_hdr(skb)->protocol == IPPROTO_ICMP) { - if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo, - state->hook)) - return NF_DROP; - else - return NF_ACCEPT; - } - } - - return nf_nat_inet_fn(priv, skb, state); -} - -static unsigned int -nf_nat_ipv4_in(void *priv, struct sk_buff *skb, - const struct nf_hook_state *state) -{ - unsigned int ret; - __be32 daddr = ip_hdr(skb)->daddr; - - ret = nf_nat_ipv4_fn(priv, skb, state); - if (ret != NF_DROP && ret != NF_STOLEN && - daddr != ip_hdr(skb)->daddr) - skb_dst_drop(skb); - - return ret; -} - -static unsigned int -nf_nat_ipv4_out(void *priv, struct sk_buff *skb, - const struct nf_hook_state *state) -{ -#ifdef CONFIG_XFRM - const struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - int err; -#endif - unsigned int ret; - - ret = nf_nat_ipv4_fn(priv, skb, state); -#ifdef CONFIG_XFRM - if (ret != NF_DROP && ret != NF_STOLEN && - !(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && - (ct = nf_ct_get(skb, &ctinfo)) != NULL) { - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - - if ((ct->tuplehash[dir].tuple.src.u3.ip != - ct->tuplehash[!dir].tuple.dst.u3.ip) || - (ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP && - ct->tuplehash[dir].tuple.src.u.all != - ct->tuplehash[!dir].tuple.dst.u.all)) { - err = nf_xfrm_me_harder(state->net, skb, AF_INET); - if (err < 0) - ret = NF_DROP_ERR(err); - } - } -#endif - return ret; -} - -static unsigned int -nf_nat_ipv4_local_fn(void *priv, struct sk_buff *skb, - const struct nf_hook_state *state) -{ - const struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - unsigned int ret; - int err; - - ret = nf_nat_ipv4_fn(priv, skb, state); - if (ret != NF_DROP && ret != NF_STOLEN && - (ct = nf_ct_get(skb, &ctinfo)) != NULL) { - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - - if (ct->tuplehash[dir].tuple.dst.u3.ip != - ct->tuplehash[!dir].tuple.src.u3.ip) { - err = ip_route_me_harder(state->net, skb, RTN_UNSPEC); - if (err < 0) - ret = NF_DROP_ERR(err); - } -#ifdef CONFIG_XFRM - else if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && - ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP && - ct->tuplehash[dir].tuple.dst.u.all != - ct->tuplehash[!dir].tuple.src.u.all) { - err = nf_xfrm_me_harder(state->net, skb, AF_INET); - if (err < 0) - ret = NF_DROP_ERR(err); - } -#endif - } - return ret; -} - -static const struct nf_hook_ops nf_nat_ipv4_ops[] = { - /* Before packet filtering, change destination */ - { - .hook = nf_nat_ipv4_in, - .pf = NFPROTO_IPV4, - .hooknum = NF_INET_PRE_ROUTING, - .priority = NF_IP_PRI_NAT_DST, - }, - /* After packet filtering, change source */ - { - .hook = nf_nat_ipv4_out, - .pf = NFPROTO_IPV4, - .hooknum = NF_INET_POST_ROUTING, - .priority = NF_IP_PRI_NAT_SRC, - }, - /* Before packet filtering, change destination */ - { - .hook = nf_nat_ipv4_local_fn, - .pf = NFPROTO_IPV4, - .hooknum = NF_INET_LOCAL_OUT, - .priority = NF_IP_PRI_NAT_DST, - }, - /* After packet filtering, change source */ - { - .hook = nf_nat_ipv4_fn, - .pf = NFPROTO_IPV4, - .hooknum = NF_INET_LOCAL_IN, - .priority = NF_IP_PRI_NAT_SRC, - }, -}; - -int nf_nat_l3proto_ipv4_register_fn(struct net *net, const struct nf_hook_ops *ops) -{ - return nf_nat_register_fn(net, ops, nf_nat_ipv4_ops, ARRAY_SIZE(nf_nat_ipv4_ops)); -} -EXPORT_SYMBOL_GPL(nf_nat_l3proto_ipv4_register_fn); - -void nf_nat_l3proto_ipv4_unregister_fn(struct net *net, const struct nf_hook_ops *ops) -{ - nf_nat_unregister_fn(net, ops, ARRAY_SIZE(nf_nat_ipv4_ops)); -} -EXPORT_SYMBOL_GPL(nf_nat_l3proto_ipv4_unregister_fn); - -static int __init nf_nat_l3proto_ipv4_init(void) -{ - return nf_nat_l3proto_register(&nf_nat_l3proto_ipv4); -} - -static void __exit nf_nat_l3proto_ipv4_exit(void) -{ - nf_nat_l3proto_unregister(&nf_nat_l3proto_ipv4); -} - -MODULE_LICENSE("GPL"); -MODULE_ALIAS("nf-nat-" __stringify(AF_INET)); - -module_init(nf_nat_l3proto_ipv4_init); -module_exit(nf_nat_l3proto_ipv4_exit); |