blob: 462f2a76b5c2270dba806e193a4c5bde57e14a39 [file] [log] [blame]
Vlad Yasevich3c73a032012-11-15 08:49:20 +00001/*
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.
4 */
5#include <linux/export.h>
Ben Hutchings5188cd42014-10-30 18:27:17 +00006#include <net/ip.h>
Vlad Yasevich3c73a032012-11-15 08:49:20 +00007#include <net/ipv6.h>
8#include <net/ip6_fib.h>
Cong Wang3ce9b352013-08-31 13:44:28 +08009#include <net/addrconf.h>
Hannes Frederic Sowa6dfac5c2014-03-30 18:28:03 +020010#include <net/secure_seq.h>
Pablo Neira Ayusoa2636532015-06-17 10:28:27 -050011#include <linux/netfilter.h>
Vlad Yasevich3c73a032012-11-15 08:49:20 +000012
Hannes Frederic Sowa5a352dd2015-03-25 17:07:45 +010013static u32 __ipv6_select_ident(struct net *net, u32 hashrnd,
Martin KaFai Laufd0273d2015-05-22 20:55:57 -070014 const struct in6_addr *dst,
15 const struct in6_addr *src)
Vlad Yasevich0508c072015-02-03 16:36:15 -050016{
17 u32 hash, id;
18
19 hash = __ipv6_addr_jhash(dst, hashrnd);
20 hash = __ipv6_addr_jhash(src, hash);
Hannes Frederic Sowa5a352dd2015-03-25 17:07:45 +010021 hash ^= net_hash_mix(net);
Vlad Yasevich0508c072015-02-03 16:36:15 -050022
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
25 * collisions.
26 */
27 id = ip_idents_reserve(hash, 1);
28 if (unlikely(!id))
29 id = 1 << 31;
30
31 return id;
32}
33
Ben Hutchings5188cd42014-10-30 18:27:17 +000034/* This function exists only for tap drivers that must support broken
35 * clients requesting UFO without specifying an IPv6 fragment ID.
36 *
37 * This is similar to ipv6_select_ident() but we use an independent hash
38 * seed to limit information leakage.
39 *
40 * The network header must be set before calling this.
41 */
Hannes Frederic Sowa5a352dd2015-03-25 17:07:45 +010042void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
Ben Hutchings5188cd42014-10-30 18:27:17 +000043{
44 static u32 ip6_proxy_idents_hashrnd __read_mostly;
45 struct in6_addr buf[2];
46 struct in6_addr *addrs;
Vlad Yasevich0508c072015-02-03 16:36:15 -050047 u32 id;
Ben Hutchings5188cd42014-10-30 18:27:17 +000048
49 addrs = skb_header_pointer(skb,
50 skb_network_offset(skb) +
51 offsetof(struct ipv6hdr, saddr),
52 sizeof(buf), buf);
53 if (!addrs)
54 return;
55
56 net_get_random_once(&ip6_proxy_idents_hashrnd,
57 sizeof(ip6_proxy_idents_hashrnd));
58
Hannes Frederic Sowa5a352dd2015-03-25 17:07:45 +010059 id = __ipv6_select_ident(net, ip6_proxy_idents_hashrnd,
Vlad Yasevich0508c072015-02-03 16:36:15 -050060 &addrs[1], &addrs[0]);
Vlad Yasevich51f30772015-02-09 09:38:20 -050061 skb_shinfo(skb)->ip6_frag_id = htonl(id);
Ben Hutchings5188cd42014-10-30 18:27:17 +000062}
63EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
64
Eric Dumazet7f159862015-05-25 16:02:21 -070065__be32 ipv6_select_ident(struct net *net,
66 const struct in6_addr *daddr,
67 const struct in6_addr *saddr)
Vlad Yasevich0508c072015-02-03 16:36:15 -050068{
69 static u32 ip6_idents_hashrnd __read_mostly;
70 u32 id;
71
72 net_get_random_once(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd));
73
Martin KaFai Laufd0273d2015-05-22 20:55:57 -070074 id = __ipv6_select_ident(net, ip6_idents_hashrnd, daddr, saddr);
Martin KaFai Lau286c2342015-05-22 20:55:56 -070075 return htonl(id);
Vlad Yasevich0508c072015-02-03 16:36:15 -050076}
77EXPORT_SYMBOL(ipv6_select_ident);
78
Vlad Yasevich3c73a032012-11-15 08:49:20 +000079int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
80{
81 u16 offset = sizeof(struct ipv6hdr);
82 struct ipv6_opt_hdr *exthdr =
83 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
Simon Horman29a3cad2013-05-28 20:34:26 +000084 unsigned int packet_len = skb_tail_pointer(skb) -
85 skb_network_header(skb);
Vlad Yasevich3c73a032012-11-15 08:49:20 +000086 int found_rhdr = 0;
87 *nexthdr = &ipv6_hdr(skb)->nexthdr;
88
89 while (offset + 1 <= packet_len) {
90
91 switch (**nexthdr) {
92
93 case NEXTHDR_HOP:
94 break;
95 case NEXTHDR_ROUTING:
96 found_rhdr = 1;
97 break;
98 case NEXTHDR_DEST:
99#if IS_ENABLED(CONFIG_IPV6_MIP6)
100 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
101 break;
102#endif
103 if (found_rhdr)
104 return offset;
105 break;
Ian Morris67ba4152014-08-24 21:53:10 +0100106 default:
Vlad Yasevich3c73a032012-11-15 08:49:20 +0000107 return offset;
108 }
109
110 offset += ipv6_optlen(exthdr);
111 *nexthdr = &exthdr->nexthdr;
112 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
113 offset);
114 }
115
116 return offset;
117}
118EXPORT_SYMBOL(ip6_find_1stfragopt);
Cong Wang3ce9b352013-08-31 13:44:28 +0800119
120#if IS_ENABLED(CONFIG_IPV6)
121int ip6_dst_hoplimit(struct dst_entry *dst)
122{
123 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
124 if (hoplimit == 0) {
125 struct net_device *dev = dst->dev;
126 struct inet6_dev *idev;
127
128 rcu_read_lock();
129 idev = __in6_dev_get(dev);
130 if (idev)
131 hoplimit = idev->cnf.hop_limit;
132 else
133 hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
134 rcu_read_unlock();
135 }
136 return hoplimit;
137}
138EXPORT_SYMBOL(ip6_dst_hoplimit);
139#endif
Cong Wang788787b2013-08-31 13:44:29 +0800140
Eric W. Biedermancf91a992015-10-07 16:48:45 -0500141int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
Cong Wang788787b2013-08-31 13:44:29 +0800142{
143 int len;
144
145 len = skb->len - sizeof(struct ipv6hdr);
146 if (len > IPV6_MAXPLEN)
147 len = 0;
148 ipv6_hdr(skb)->payload_len = htons(len);
huizhangf6c20c52014-06-09 12:37:25 +0800149 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
Cong Wang788787b2013-08-31 13:44:29 +0800150
Eric W. Biederman29a26a52015-09-15 20:04:16 -0500151 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
152 net, sk, skb, NULL, skb_dst(skb)->dev,
Eric W. Biederman13206b62015-10-07 16:48:35 -0500153 dst_output);
Cong Wang788787b2013-08-31 13:44:29 +0800154}
155EXPORT_SYMBOL_GPL(__ip6_local_out);
156
Eric W. Biederman33224b12015-10-07 16:48:46 -0500157int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
Cong Wang788787b2013-08-31 13:44:29 +0800158{
159 int err;
160
Eric W. Biedermancf91a992015-10-07 16:48:45 -0500161 err = __ip6_local_out(net, sk, skb);
Cong Wang788787b2013-08-31 13:44:29 +0800162 if (likely(err == 1))
Eric W. Biederman13206b62015-10-07 16:48:35 -0500163 err = dst_output(net, sk, skb);
Cong Wang788787b2013-08-31 13:44:29 +0800164
165 return err;
166}
167EXPORT_SYMBOL_GPL(ip6_local_out);