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>
12 /* This function exists only for tap drivers that must support broken
13 * clients requesting UFO without specifying an IPv6 fragment ID.
15 * This is similar to ipv6_select_ident() but we use an independent hash
16 * seed to limit information leakage.
18 * The network header must be set before calling this.
20 void ipv6_proxy_select_ident(struct sk_buff *skb)
22 static u32 ip6_proxy_idents_hashrnd __read_mostly;
23 struct in6_addr buf[2];
24 struct in6_addr *addrs;
27 addrs = skb_header_pointer(skb,
28 skb_network_offset(skb) +
29 offsetof(struct ipv6hdr, saddr),
34 net_get_random_once(&ip6_proxy_idents_hashrnd,
35 sizeof(ip6_proxy_idents_hashrnd));
37 hash = __ipv6_addr_jhash(&addrs[1], ip6_proxy_idents_hashrnd);
38 hash = __ipv6_addr_jhash(&addrs[0], hash);
40 id = ip_idents_reserve(hash, 1);
41 skb_shinfo(skb)->ip6_frag_id = htonl(id);
43 EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
45 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
47 u16 offset = sizeof(struct ipv6hdr);
48 struct ipv6_opt_hdr *exthdr =
49 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
50 unsigned int packet_len = skb_tail_pointer(skb) -
51 skb_network_header(skb);
53 *nexthdr = &ipv6_hdr(skb)->nexthdr;
55 while (offset + 1 <= packet_len) {
65 #if IS_ENABLED(CONFIG_IPV6_MIP6)
66 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
76 offset += ipv6_optlen(exthdr);
77 *nexthdr = &exthdr->nexthdr;
78 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
84 EXPORT_SYMBOL(ip6_find_1stfragopt);
86 #if IS_ENABLED(CONFIG_IPV6)
87 int ip6_dst_hoplimit(struct dst_entry *dst)
89 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
91 struct net_device *dev = dst->dev;
92 struct inet6_dev *idev;
95 idev = __in6_dev_get(dev);
97 hoplimit = idev->cnf.hop_limit;
99 hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
104 EXPORT_SYMBOL(ip6_dst_hoplimit);
107 int __ip6_local_out(struct sk_buff *skb)
111 len = skb->len - sizeof(struct ipv6hdr);
112 if (len > IPV6_MAXPLEN)
114 ipv6_hdr(skb)->payload_len = htons(len);
115 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
117 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
118 skb_dst(skb)->dev, dst_output);
120 EXPORT_SYMBOL_GPL(__ip6_local_out);
122 int ip6_local_out(struct sk_buff *skb)
126 err = __ip6_local_out(skb);
127 if (likely(err == 1))
128 err = dst_output(skb);
132 EXPORT_SYMBOL_GPL(ip6_local_out);