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path: root/net/ipv6/netfilter/ip6table_nat.c
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Diffstat (limited to 'net/ipv6/netfilter/ip6table_nat.c')
-rw-r--r--net/ipv6/netfilter/ip6table_nat.c233
1 files changed, 34 insertions, 199 deletions
diff --git a/net/ipv6/netfilter/ip6table_nat.c b/net/ipv6/netfilter/ip6table_nat.c
index 387d8b8fc18d..b0634ac996b7 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,
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.