2 * IPv6 library code, needed by static components when full IPv6 support is
3 * not configured or static. These functions are needed by GSO/GRO implementation.
5 #include <linux/export.h>
8 #include <net/ip6_fib.h>
9 #include <net/addrconf.h>
10 #include <net/secure_seq.h>
11 #include <linux/netfilter.h>
13 static u32 __ipv6_select_ident(struct net *net,
14 const struct in6_addr *dst,
15 const struct in6_addr *src)
20 } __aligned(SIPHASH_ALIGNMENT) combined = {
26 /* Note the following code is not safe, but this is okay. */
27 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key)))
28 get_random_bytes(&net->ipv4.ip_id_key,
29 sizeof(net->ipv4.ip_id_key));
31 hash = siphash(&combined, sizeof(combined), &net->ipv4.ip_id_key);
33 /* Treat id of 0 as unset and if we get 0 back from ip_idents_reserve,
34 * set the hight order instead thus minimizing possible future
37 id = ip_idents_reserve(hash, 1);
44 /* This function exists only for tap drivers that must support broken
45 * clients requesting UFO without specifying an IPv6 fragment ID.
47 * This is similar to ipv6_select_ident() but we use an independent hash
48 * seed to limit information leakage.
50 * The network header must be set before calling this.
52 __be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
54 struct in6_addr buf[2];
55 struct in6_addr *addrs;
58 addrs = skb_header_pointer(skb,
59 skb_network_offset(skb) +
60 offsetof(struct ipv6hdr, saddr),
65 id = __ipv6_select_ident(net, &addrs[1], &addrs[0]);
68 EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
70 __be32 ipv6_select_ident(struct net *net,
71 const struct in6_addr *daddr,
72 const struct in6_addr *saddr)
76 id = __ipv6_select_ident(net, daddr, saddr);
79 EXPORT_SYMBOL(ipv6_select_ident);
81 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
83 unsigned int offset = sizeof(struct ipv6hdr);
84 unsigned int packet_len = skb_tail_pointer(skb) -
85 skb_network_header(skb);
87 *nexthdr = &ipv6_hdr(skb)->nexthdr;
89 while (offset <= packet_len) {
90 struct ipv6_opt_hdr *exthdr;
100 #if IS_ENABLED(CONFIG_IPV6_MIP6)
101 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
111 if (offset + sizeof(struct ipv6_opt_hdr) > packet_len)
114 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
116 offset += ipv6_optlen(exthdr);
117 if (offset > IPV6_MAXPLEN)
119 *nexthdr = &exthdr->nexthdr;
124 EXPORT_SYMBOL(ip6_find_1stfragopt);
126 #if IS_ENABLED(CONFIG_IPV6)
127 int ip6_dst_hoplimit(struct dst_entry *dst)
129 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
131 struct net_device *dev = dst->dev;
132 struct inet6_dev *idev;
135 idev = __in6_dev_get(dev);
137 hoplimit = idev->cnf.hop_limit;
139 hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
144 EXPORT_SYMBOL(ip6_dst_hoplimit);
147 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
151 len = skb->len - sizeof(struct ipv6hdr);
152 if (len > IPV6_MAXPLEN)
154 ipv6_hdr(skb)->payload_len = htons(len);
155 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
157 /* if egress device is enslaved to an L3 master device pass the
158 * skb to its handler for processing
160 skb = l3mdev_ip6_out(sk, skb);
164 skb->protocol = htons(ETH_P_IPV6);
166 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
167 net, sk, skb, NULL, skb_dst(skb)->dev,
170 EXPORT_SYMBOL_GPL(__ip6_local_out);
172 int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
176 err = __ip6_local_out(net, sk, skb);
177 if (likely(err == 1))
178 err = dst_output(net, sk, skb);
182 EXPORT_SYMBOL_GPL(ip6_local_out);