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, u32 hashrnd,
14 const struct in6_addr *dst,
15 const struct in6_addr *src)
19 hash = __ipv6_addr_jhash(dst, hashrnd);
20 hash = __ipv6_addr_jhash(src, hash);
21 hash ^= net_hash_mix(net);
23 /* Treat id of 0 as unset and if we get 0 back from ip_idents_reserve,
24 * set the hight order instead thus minimizing possible future
27 id = ip_idents_reserve(hash, 1);
34 /* This function exists only for tap drivers that must support broken
35 * clients requesting UFO without specifying an IPv6 fragment ID.
37 * This is similar to ipv6_select_ident() but we use an independent hash
38 * seed to limit information leakage.
40 * The network header must be set before calling this.
42 __be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
44 static u32 ip6_proxy_idents_hashrnd __read_mostly;
45 struct in6_addr buf[2];
46 struct in6_addr *addrs;
49 addrs = skb_header_pointer(skb,
50 skb_network_offset(skb) +
51 offsetof(struct ipv6hdr, saddr),
56 net_get_random_once(&ip6_proxy_idents_hashrnd,
57 sizeof(ip6_proxy_idents_hashrnd));
59 id = __ipv6_select_ident(net, ip6_proxy_idents_hashrnd,
60 &addrs[1], &addrs[0]);
63 EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
65 __be32 ipv6_select_ident(struct net *net,
66 const struct in6_addr *daddr,
67 const struct in6_addr *saddr)
69 static u32 ip6_idents_hashrnd __read_mostly;
72 net_get_random_once(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd));
74 id = __ipv6_select_ident(net, ip6_idents_hashrnd, daddr, saddr);
77 EXPORT_SYMBOL(ipv6_select_ident);
79 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
81 unsigned int offset = sizeof(struct ipv6hdr);
82 unsigned int packet_len = skb_tail_pointer(skb) -
83 skb_network_header(skb);
85 *nexthdr = &ipv6_hdr(skb)->nexthdr;
87 while (offset <= packet_len) {
88 struct ipv6_opt_hdr *exthdr;
98 #if IS_ENABLED(CONFIG_IPV6_MIP6)
99 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
109 if (offset + sizeof(struct ipv6_opt_hdr) > packet_len)
112 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
114 offset += ipv6_optlen(exthdr);
115 if (offset > IPV6_MAXPLEN)
117 *nexthdr = &exthdr->nexthdr;
122 EXPORT_SYMBOL(ip6_find_1stfragopt);
124 #if IS_ENABLED(CONFIG_IPV6)
125 int ip6_dst_hoplimit(struct dst_entry *dst)
127 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
129 struct net_device *dev = dst->dev;
130 struct inet6_dev *idev;
133 idev = __in6_dev_get(dev);
135 hoplimit = idev->cnf.hop_limit;
137 hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
142 EXPORT_SYMBOL(ip6_dst_hoplimit);
145 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
149 len = skb->len - sizeof(struct ipv6hdr);
150 if (len > IPV6_MAXPLEN)
152 ipv6_hdr(skb)->payload_len = htons(len);
153 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
155 /* if egress device is enslaved to an L3 master device pass the
156 * skb to its handler for processing
158 skb = l3mdev_ip6_out(sk, skb);
162 skb->protocol = htons(ETH_P_IPV6);
164 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
165 net, sk, skb, NULL, skb_dst(skb)->dev,
168 EXPORT_SYMBOL_GPL(__ip6_local_out);
170 int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
174 err = __ip6_local_out(net, sk, skb);
175 if (likely(err == 1))
176 err = dst_output(net, sk, skb);
180 EXPORT_SYMBOL_GPL(ip6_local_out);