OMAP3 SRF: Fix crash on non-3430SDP platforms with DVFS/CPUFreq
[linux-ginger.git] / net / ipv4 / netfilter.c
blob1725dc0ef68875253d02e4e6bdd777ead267d9a3
1 /* IPv4 specific functions of netfilter core */
2 #include <linux/kernel.h>
3 #include <linux/netfilter.h>
4 #include <linux/netfilter_ipv4.h>
5 #include <linux/ip.h>
6 #include <linux/skbuff.h>
7 #include <net/route.h>
8 #include <net/xfrm.h>
9 #include <net/ip.h>
10 #include <net/netfilter/nf_queue.h>
12 /* route_me_harder function, used by iptable_nat, iptable_mangle + ip_queue */
13 int ip_route_me_harder(struct sk_buff *skb, unsigned addr_type)
15 struct net *net = dev_net(skb_dst(skb)->dev);
16 const struct iphdr *iph = ip_hdr(skb);
17 struct rtable *rt;
18 struct flowi fl = {};
19 struct dst_entry *odst;
20 unsigned int hh_len;
21 unsigned int type;
23 type = inet_addr_type(net, iph->saddr);
24 if (skb->sk && inet_sk(skb->sk)->transparent)
25 type = RTN_LOCAL;
26 if (addr_type == RTN_UNSPEC)
27 addr_type = type;
29 /* some non-standard hacks like ipt_REJECT.c:send_reset() can cause
30 * packets with foreign saddr to appear on the NF_INET_LOCAL_OUT hook.
32 if (addr_type == RTN_LOCAL) {
33 fl.nl_u.ip4_u.daddr = iph->daddr;
34 if (type == RTN_LOCAL)
35 fl.nl_u.ip4_u.saddr = iph->saddr;
36 fl.nl_u.ip4_u.tos = RT_TOS(iph->tos);
37 fl.oif = skb->sk ? skb->sk->sk_bound_dev_if : 0;
38 fl.mark = skb->mark;
39 fl.flags = skb->sk ? inet_sk_flowi_flags(skb->sk) : 0;
40 if (ip_route_output_key(net, &rt, &fl) != 0)
41 return -1;
43 /* Drop old route. */
44 skb_dst_drop(skb);
45 skb_dst_set(skb, &rt->u.dst);
46 } else {
47 /* non-local src, find valid iif to satisfy
48 * rp-filter when calling ip_route_input. */
49 fl.nl_u.ip4_u.daddr = iph->saddr;
50 if (ip_route_output_key(net, &rt, &fl) != 0)
51 return -1;
53 odst = skb_dst(skb);
54 if (ip_route_input(skb, iph->daddr, iph->saddr,
55 RT_TOS(iph->tos), rt->u.dst.dev) != 0) {
56 dst_release(&rt->u.dst);
57 return -1;
59 dst_release(&rt->u.dst);
60 dst_release(odst);
63 if (skb_dst(skb)->error)
64 return -1;
66 #ifdef CONFIG_XFRM
67 if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) &&
68 xfrm_decode_session(skb, &fl, AF_INET) == 0) {
69 struct dst_entry *dst = skb_dst(skb);
70 skb_dst_set(skb, NULL);
71 if (xfrm_lookup(net, &dst, &fl, skb->sk, 0))
72 return -1;
73 skb_dst_set(skb, dst);
75 #endif
77 /* Change in oif may mean change in hh_len. */
78 hh_len = skb_dst(skb)->dev->hard_header_len;
79 if (skb_headroom(skb) < hh_len &&
80 pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
81 return -1;
83 return 0;
85 EXPORT_SYMBOL(ip_route_me_harder);
87 #ifdef CONFIG_XFRM
88 int ip_xfrm_me_harder(struct sk_buff *skb)
90 struct flowi fl;
91 unsigned int hh_len;
92 struct dst_entry *dst;
94 if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
95 return 0;
96 if (xfrm_decode_session(skb, &fl, AF_INET) < 0)
97 return -1;
99 dst = skb_dst(skb);
100 if (dst->xfrm)
101 dst = ((struct xfrm_dst *)dst)->route;
102 dst_hold(dst);
104 if (xfrm_lookup(dev_net(dst->dev), &dst, &fl, skb->sk, 0) < 0)
105 return -1;
107 skb_dst_drop(skb);
108 skb_dst_set(skb, dst);
110 /* Change in oif may mean change in hh_len. */
111 hh_len = skb_dst(skb)->dev->hard_header_len;
112 if (skb_headroom(skb) < hh_len &&
113 pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
114 return -1;
115 return 0;
117 EXPORT_SYMBOL(ip_xfrm_me_harder);
118 #endif
120 void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *);
121 EXPORT_SYMBOL(ip_nat_decode_session);
124 * Extra routing may needed on local out, as the QUEUE target never
125 * returns control to the table.
128 struct ip_rt_info {
129 __be32 daddr;
130 __be32 saddr;
131 u_int8_t tos;
132 u_int32_t mark;
135 static void nf_ip_saveroute(const struct sk_buff *skb,
136 struct nf_queue_entry *entry)
138 struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry);
140 if (entry->hook == NF_INET_LOCAL_OUT) {
141 const struct iphdr *iph = ip_hdr(skb);
143 rt_info->tos = iph->tos;
144 rt_info->daddr = iph->daddr;
145 rt_info->saddr = iph->saddr;
146 rt_info->mark = skb->mark;
150 static int nf_ip_reroute(struct sk_buff *skb,
151 const struct nf_queue_entry *entry)
153 const struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry);
155 if (entry->hook == NF_INET_LOCAL_OUT) {
156 const struct iphdr *iph = ip_hdr(skb);
158 if (!(iph->tos == rt_info->tos
159 && skb->mark == rt_info->mark
160 && iph->daddr == rt_info->daddr
161 && iph->saddr == rt_info->saddr))
162 return ip_route_me_harder(skb, RTN_UNSPEC);
164 return 0;
167 __sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
168 unsigned int dataoff, u_int8_t protocol)
170 const struct iphdr *iph = ip_hdr(skb);
171 __sum16 csum = 0;
173 switch (skb->ip_summed) {
174 case CHECKSUM_COMPLETE:
175 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
176 break;
177 if ((protocol == 0 && !csum_fold(skb->csum)) ||
178 !csum_tcpudp_magic(iph->saddr, iph->daddr,
179 skb->len - dataoff, protocol,
180 skb->csum)) {
181 skb->ip_summed = CHECKSUM_UNNECESSARY;
182 break;
184 /* fall through */
185 case CHECKSUM_NONE:
186 if (protocol == 0)
187 skb->csum = 0;
188 else
189 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
190 skb->len - dataoff,
191 protocol, 0);
192 csum = __skb_checksum_complete(skb);
194 return csum;
196 EXPORT_SYMBOL(nf_ip_checksum);
198 static __sum16 nf_ip_checksum_partial(struct sk_buff *skb, unsigned int hook,
199 unsigned int dataoff, unsigned int len,
200 u_int8_t protocol)
202 const struct iphdr *iph = ip_hdr(skb);
203 __sum16 csum = 0;
205 switch (skb->ip_summed) {
206 case CHECKSUM_COMPLETE:
207 if (len == skb->len - dataoff)
208 return nf_ip_checksum(skb, hook, dataoff, protocol);
209 /* fall through */
210 case CHECKSUM_NONE:
211 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, protocol,
212 skb->len - dataoff, 0);
213 skb->ip_summed = CHECKSUM_NONE;
214 csum = __skb_checksum_complete_head(skb, dataoff + len);
215 if (!csum)
216 skb->ip_summed = CHECKSUM_UNNECESSARY;
218 return csum;
221 static int nf_ip_route(struct dst_entry **dst, struct flowi *fl)
223 return ip_route_output_key(&init_net, (struct rtable **)dst, fl);
226 static const struct nf_afinfo nf_ip_afinfo = {
227 .family = AF_INET,
228 .checksum = nf_ip_checksum,
229 .checksum_partial = nf_ip_checksum_partial,
230 .route = nf_ip_route,
231 .saveroute = nf_ip_saveroute,
232 .reroute = nf_ip_reroute,
233 .route_key_size = sizeof(struct ip_rt_info),
236 static int ipv4_netfilter_init(void)
238 return nf_register_afinfo(&nf_ip_afinfo);
241 static void ipv4_netfilter_fini(void)
243 nf_unregister_afinfo(&nf_ip_afinfo);
246 module_init(ipv4_netfilter_init);
247 module_exit(ipv4_netfilter_fini);
249 #ifdef CONFIG_SYSCTL
250 struct ctl_path nf_net_ipv4_netfilter_sysctl_path[] = {
251 { .procname = "net", .ctl_name = CTL_NET, },
252 { .procname = "ipv4", .ctl_name = NET_IPV4, },
253 { .procname = "netfilter", .ctl_name = NET_IPV4_NETFILTER, },
256 EXPORT_SYMBOL_GPL(nf_net_ipv4_netfilter_sysctl_path);
257 #endif /* CONFIG_SYSCTL */