1 From: Pablo Neira Ayuso <pablo@netfilter.org>
2 Date: Mon, 27 Nov 2017 22:50:26 +0100
3 Subject: [PATCH] netfilter: move reroute indirection to struct nf_ipv6_ops
5 We cannot make a direct call to nf_ip6_reroute() because that would result
6 in autoloading the 'ipv6' module because of symbol dependencies.
7 Therefore, define reroute indirection in nf_ipv6_ops where this really
10 For IPv4, we can indeed make a direct function call, which is faster,
11 given IPv4 is built-in in the networking code by default. Still,
12 CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline
13 stub for IPv4 in such case.
15 Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
18 --- a/include/linux/netfilter.h
19 +++ b/include/linux/netfilter.h
20 @@ -311,8 +311,6 @@ struct nf_queue_entry;
23 unsigned short family;
24 - int (*reroute)(struct net *net, struct sk_buff *skb,
25 - const struct nf_queue_entry *entry);
29 @@ -331,6 +329,7 @@ __sum16 nf_checksum_partial(struct sk_bu
30 u_int8_t protocol, unsigned short family);
31 int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
32 bool strict, unsigned short family);
33 +int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry);
35 int nf_register_afinfo(const struct nf_afinfo *afinfo);
36 void nf_unregister_afinfo(const struct nf_afinfo *afinfo);
37 --- a/include/linux/netfilter_ipv4.h
38 +++ b/include/linux/netfilter_ipv4.h
39 @@ -18,6 +18,8 @@ struct ip_rt_info {
41 int ip_route_me_harder(struct net *net, struct sk_buff *skb, unsigned addr_type);
43 +struct nf_queue_entry;
46 __sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
47 unsigned int dataoff, u_int8_t protocol);
48 @@ -26,6 +28,7 @@ __sum16 nf_ip_checksum_partial(struct sk
50 int nf_ip_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
52 +int nf_ip_reroute(struct sk_buff *skb, const struct nf_queue_entry *entry);
54 static inline __sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
55 unsigned int dataoff, u_int8_t protocol)
56 @@ -45,6 +48,11 @@ static inline int nf_ip_route(struct net
60 +static inline int nf_ip_reroute(struct sk_buff *skb,
61 + const struct nf_queue_entry *entry)
65 #endif /* CONFIG_INET */
67 #endif /*__LINUX_IP_NETFILTER_H*/
68 --- a/include/linux/netfilter_ipv6.h
69 +++ b/include/linux/netfilter_ipv6.h
70 @@ -18,6 +18,8 @@ struct ip6_rt_info {
74 +struct nf_queue_entry;
77 * Hook functions for ipv6 to allow xt_* modules to be built-in even
78 * if IPv6 is a module.
79 @@ -35,6 +37,7 @@ struct nf_ipv6_ops {
81 int (*route)(struct net *net, struct dst_entry **dst, struct flowi *fl,
83 + int (*reroute)(struct sk_buff *skb, const struct nf_queue_entry *entry);
86 #ifdef CONFIG_NETFILTER
87 --- a/net/bridge/netfilter/nf_tables_bridge.c
88 +++ b/net/bridge/netfilter/nf_tables_bridge.c
89 @@ -95,15 +95,8 @@ static const struct nf_chain_type filter
90 (1 << NF_BR_POST_ROUTING),
93 -static int nf_br_reroute(struct net *net, struct sk_buff *skb,
94 - const struct nf_queue_entry *entry)
99 static const struct nf_afinfo nf_br_afinfo = {
101 - .reroute = nf_br_reroute,
105 --- a/net/ipv4/netfilter.c
106 +++ b/net/ipv4/netfilter.c
107 @@ -80,8 +80,7 @@ int ip_route_me_harder(struct net *net,
109 EXPORT_SYMBOL(ip_route_me_harder);
111 -static int nf_ip_reroute(struct net *net, struct sk_buff *skb,
112 - const struct nf_queue_entry *entry)
113 +int nf_ip_reroute(struct sk_buff *skb, const struct nf_queue_entry *entry)
115 const struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry);
117 @@ -92,10 +91,12 @@ static int nf_ip_reroute(struct net *net
118 skb->mark == rt_info->mark &&
119 iph->daddr == rt_info->daddr &&
120 iph->saddr == rt_info->saddr))
121 - return ip_route_me_harder(net, skb, RTN_UNSPEC);
122 + return ip_route_me_harder(entry->state.net, skb,
127 +EXPORT_SYMBOL_GPL(nf_ip_reroute);
129 __sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
130 unsigned int dataoff, u_int8_t protocol)
131 @@ -163,7 +164,6 @@ EXPORT_SYMBOL_GPL(nf_ip_route);
133 static const struct nf_afinfo nf_ip_afinfo = {
135 - .reroute = nf_ip_reroute,
136 .route_key_size = sizeof(struct ip_rt_info),
139 --- a/net/ipv6/netfilter.c
140 +++ b/net/ipv6/netfilter.c
141 @@ -72,7 +72,7 @@ int ip6_route_me_harder(struct net *net,
143 EXPORT_SYMBOL(ip6_route_me_harder);
145 -static int nf_ip6_reroute(struct net *net, struct sk_buff *skb,
146 +static int nf_ip6_reroute(struct sk_buff *skb,
147 const struct nf_queue_entry *entry)
149 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
150 @@ -82,7 +82,7 @@ static int nf_ip6_reroute(struct net *ne
151 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
152 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
153 skb->mark != rt_info->mark)
154 - return ip6_route_me_harder(net, skb);
155 + return ip6_route_me_harder(entry->state.net, skb);
159 @@ -175,11 +175,11 @@ static const struct nf_ipv6_ops ipv6ops
160 .checksum = nf_ip6_checksum,
161 .checksum_partial = nf_ip6_checksum_partial,
162 .route = nf_ip6_route,
163 + .reroute = nf_ip6_reroute,
166 static const struct nf_afinfo nf_ip6_afinfo = {
168 - .reroute = nf_ip6_reroute,
169 .route_key_size = sizeof(struct ip6_rt_info),
172 --- a/net/netfilter/nf_queue.c
173 +++ b/net/netfilter/nf_queue.c
174 @@ -271,7 +271,6 @@ void nf_reinject(struct nf_queue_entry *
175 const struct nf_hook_entry *hook_entry;
176 const struct nf_hook_entries *hooks;
177 struct sk_buff *skb = entry->skb;
178 - const struct nf_afinfo *afinfo;
179 const struct net *net;
182 @@ -298,8 +297,7 @@ void nf_reinject(struct nf_queue_entry *
183 verdict = nf_hook_entry_hookfn(hook_entry, skb, &entry->state);
185 if (verdict == NF_ACCEPT) {
186 - afinfo = nf_get_afinfo(entry->state.pf);
187 - if (!afinfo || afinfo->reroute(entry->state.net, skb, entry) < 0)
188 + if (nf_reroute(skb, entry) < 0)
192 --- a/net/netfilter/utils.c
193 +++ b/net/netfilter/utils.c
195 #include <linux/netfilter.h>
196 #include <linux/netfilter_ipv4.h>
197 #include <linux/netfilter_ipv6.h>
198 +#include <net/netfilter/nf_queue.h>
200 __sum16 nf_checksum(struct sk_buff *skb, unsigned int hook,
201 unsigned int dataoff, u_int8_t protocol,
202 @@ -69,3 +70,21 @@ int nf_route(struct net *net, struct dst
205 EXPORT_SYMBOL_GPL(nf_route);
207 +int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry)
209 + const struct nf_ipv6_ops *v6ops;
212 + switch (entry->state.pf) {
214 + ret = nf_ip_reroute(skb, entry);
217 + v6ops = rcu_dereference(nf_ipv6_ops);
219 + ret = v6ops->reroute(skb, entry);