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>
This commit is contained in:
Florian Westphal 2019-02-19 17:38:21 +01:00 committed by Pablo Neira Ayuso
parent 096d09067a
commit 3bf195ae60
12 changed files with 711 additions and 738 deletions

View file

@ -8,8 +8,6 @@ config OPENVSWITCH
depends on !NF_CONNTRACK || \
(NF_CONNTRACK && ((!NF_DEFRAG_IPV6 || NF_DEFRAG_IPV6) && \
(!NF_NAT || NF_NAT) && \
(!NF_NAT_IPV4 || NF_NAT_IPV4) && \
(!NF_NAT_IPV6 || NF_NAT_IPV6) && \
(!NETFILTER_CONNCOUNT || NETFILTER_CONNCOUNT)))
select LIBCRC32C
select MPLS

View file

@ -745,14 +745,14 @@ static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
switch (ctinfo) {
case IP_CT_RELATED:
case IP_CT_RELATED_REPLY:
if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
if (IS_ENABLED(CONFIG_NF_NAT) &&
skb->protocol == htons(ETH_P_IP) &&
ip_hdr(skb)->protocol == IPPROTO_ICMP) {
if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
hooknum))
err = NF_DROP;
goto push;
} else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
} else if (IS_ENABLED(CONFIG_IPV6) &&
skb->protocol == htons(ETH_P_IPV6)) {
__be16 frag_off;
u8 nexthdr = ipv6_hdr(skb)->nexthdr;
@ -1673,7 +1673,7 @@ static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
}
if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
if (IS_ENABLED(CONFIG_NF_NAT) &&
info->family == NFPROTO_IPV4) {
if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
info->range.min_addr.ip) ||
@ -1682,7 +1682,7 @@ static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
(nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
info->range.max_addr.ip))))
return false;
} else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
} else if (IS_ENABLED(CONFIG_IPV6) &&
info->family == NFPROTO_IPV6) {
if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
&info->range.min_addr.in6) ||