1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/netfilter.h>
4 #include <linux/netfilter_ipv4.h>
5 #include <linux/netfilter_ipv6.h>
6 #include <net/netfilter/nf_queue.h>
7 #include <net/ip6_checksum.h>
10 __sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
11 unsigned int dataoff, u8 protocol)
13 const struct iphdr *iph = ip_hdr(skb);
16 switch (skb->ip_summed) {
17 case CHECKSUM_COMPLETE:
18 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
20 if ((protocol != IPPROTO_TCP && protocol != IPPROTO_UDP &&
21 !csum_fold(skb->csum)) ||
22 !csum_tcpudp_magic(iph->saddr, iph->daddr,
23 skb->len - dataoff, protocol,
25 skb->ip_summed = CHECKSUM_UNNECESSARY;
30 if (protocol != IPPROTO_TCP && protocol != IPPROTO_UDP)
33 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
36 csum = __skb_checksum_complete(skb);
40 EXPORT_SYMBOL(nf_ip_checksum);
43 static __sum16 nf_ip_checksum_partial(struct sk_buff *skb, unsigned int hook,
44 unsigned int dataoff, unsigned int len,
47 const struct iphdr *iph = ip_hdr(skb);
50 switch (skb->ip_summed) {
51 case CHECKSUM_COMPLETE:
52 if (len == skb->len - dataoff)
53 return nf_ip_checksum(skb, hook, dataoff, protocol);
56 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, protocol,
57 skb->len - dataoff, 0);
58 skb->ip_summed = CHECKSUM_NONE;
59 return __skb_checksum_complete_head(skb, dataoff + len);
64 __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
65 unsigned int dataoff, u8 protocol)
67 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
70 switch (skb->ip_summed) {
71 case CHECKSUM_COMPLETE:
72 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
74 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
75 skb->len - dataoff, protocol,
79 skb->ip_summed = CHECKSUM_UNNECESSARY;
84 skb->csum = ~csum_unfold(
85 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
91 csum = __skb_checksum_complete(skb);
95 EXPORT_SYMBOL(nf_ip6_checksum);
97 static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook,
98 unsigned int dataoff, unsigned int len,
101 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
105 switch (skb->ip_summed) {
106 case CHECKSUM_COMPLETE:
107 if (len == skb->len - dataoff)
108 return nf_ip6_checksum(skb, hook, dataoff, protocol);
111 hsum = skb_checksum(skb, 0, dataoff, 0);
112 skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
117 skb->ip_summed = CHECKSUM_NONE;
118 return __skb_checksum_complete_head(skb, dataoff + len);
123 __sum16 nf_checksum(struct sk_buff *skb, unsigned int hook,
124 unsigned int dataoff, u8 protocol,
125 unsigned short family)
131 csum = nf_ip_checksum(skb, hook, dataoff, protocol);
134 csum = nf_ip6_checksum(skb, hook, dataoff, protocol);
140 EXPORT_SYMBOL_GPL(nf_checksum);
142 __sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
143 unsigned int dataoff, unsigned int len,
144 u8 protocol, unsigned short family)
150 csum = nf_ip_checksum_partial(skb, hook, dataoff, len,
154 csum = nf_ip6_checksum_partial(skb, hook, dataoff, len,
161 EXPORT_SYMBOL_GPL(nf_checksum_partial);
163 int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
164 bool strict, unsigned short family)
166 const struct nf_ipv6_ops *v6ops __maybe_unused;
171 ret = nf_ip_route(net, dst, fl, strict);
174 ret = nf_ip6_route(net, dst, fl, strict);
180 EXPORT_SYMBOL_GPL(nf_route);
182 static int nf_ip_reroute(struct sk_buff *skb, const struct nf_queue_entry *entry)
185 const struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry);
187 if (entry->state.hook == NF_INET_LOCAL_OUT) {
188 const struct iphdr *iph = ip_hdr(skb);
190 if (!(iph->tos == rt_info->tos &&
191 skb->mark == rt_info->mark &&
192 iph->daddr == rt_info->daddr &&
193 iph->saddr == rt_info->saddr))
194 return ip_route_me_harder(entry->state.net, entry->state.sk,
201 int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry)
203 const struct nf_ipv6_ops *v6ops;
206 switch (entry->state.pf) {
208 ret = nf_ip_reroute(skb, entry);
211 v6ops = rcu_dereference(nf_ipv6_ops);
213 ret = v6ops->reroute(skb, entry);
219 /* Only get and check the lengths, not do any hop-by-hop stuff. */
220 int nf_ip6_check_hbh_len(struct sk_buff *skb, u32 *plen)
222 int len, off = sizeof(struct ipv6hdr);
225 if (!pskb_may_pull(skb, off + 8))
227 nh = (unsigned char *)(ipv6_hdr(skb) + 1);
228 len = (nh[1] + 1) << 3;
230 if (!pskb_may_pull(skb, off + len))
232 nh = skb_network_header(skb);
239 if (nh[off] == IPV6_TLV_PAD1) {
246 optlen = nh[off + 1] + 2;
250 if (nh[off] == IPV6_TLV_JUMBO) {
253 if (nh[off + 1] != 4 || (off & 3) != 2)
255 pkt_len = ntohl(*(__be32 *)(nh + off + 2));
256 if (pkt_len <= IPV6_MAXPLEN ||
257 ipv6_hdr(skb)->payload_len)
259 if (pkt_len > skb->len - sizeof(struct ipv6hdr))
267 return len ? -EBADMSG : 0;
269 EXPORT_SYMBOL_GPL(nf_ip6_check_hbh_len);