blob: 97f41a3e68d98b89d6b8f643780f8a883bd46f55 [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>
Vlad Yasevich3c73a032012-11-15 08:49:20 +000011
Ben Hutchings5188cd42014-10-30 18:27:17 +000012/* This function exists only for tap drivers that must support broken
13 * clients requesting UFO without specifying an IPv6 fragment ID.
14 *
15 * This is similar to ipv6_select_ident() but we use an independent hash
16 * seed to limit information leakage.
17 *
18 * The network header must be set before calling this.
19 */
20void ipv6_proxy_select_ident(struct sk_buff *skb)
21{
22 static u32 ip6_proxy_idents_hashrnd __read_mostly;
23 struct in6_addr buf[2];
24 struct in6_addr *addrs;
25 u32 hash, id;
26
27 addrs = skb_header_pointer(skb,
28 skb_network_offset(skb) +
29 offsetof(struct ipv6hdr, saddr),
30 sizeof(buf), buf);
31 if (!addrs)
32 return;
33
34 net_get_random_once(&ip6_proxy_idents_hashrnd,
35 sizeof(ip6_proxy_idents_hashrnd));
36
37 hash = __ipv6_addr_jhash(&addrs[1], ip6_proxy_idents_hashrnd);
38 hash = __ipv6_addr_jhash(&addrs[0], hash);
39
40 id = ip_idents_reserve(hash, 1);
41 skb_shinfo(skb)->ip6_frag_id = htonl(id);
42}
43EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
44
Vlad Yasevich3c73a032012-11-15 08:49:20 +000045int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
46{
47 u16 offset = sizeof(struct ipv6hdr);
48 struct ipv6_opt_hdr *exthdr =
49 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
Simon Horman29a3cad2013-05-28 20:34:26 +000050 unsigned int packet_len = skb_tail_pointer(skb) -
51 skb_network_header(skb);
Vlad Yasevich3c73a032012-11-15 08:49:20 +000052 int found_rhdr = 0;
53 *nexthdr = &ipv6_hdr(skb)->nexthdr;
54
55 while (offset + 1 <= packet_len) {
56
57 switch (**nexthdr) {
58
59 case NEXTHDR_HOP:
60 break;
61 case NEXTHDR_ROUTING:
62 found_rhdr = 1;
63 break;
64 case NEXTHDR_DEST:
65#if IS_ENABLED(CONFIG_IPV6_MIP6)
66 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
67 break;
68#endif
69 if (found_rhdr)
70 return offset;
71 break;
Ian Morris67ba4152014-08-24 21:53:10 +010072 default:
Vlad Yasevich3c73a032012-11-15 08:49:20 +000073 return offset;
74 }
75
76 offset += ipv6_optlen(exthdr);
77 *nexthdr = &exthdr->nexthdr;
78 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
79 offset);
80 }
81
82 return offset;
83}
84EXPORT_SYMBOL(ip6_find_1stfragopt);
Cong Wang3ce9b352013-08-31 13:44:28 +080085
86#if IS_ENABLED(CONFIG_IPV6)
87int ip6_dst_hoplimit(struct dst_entry *dst)
88{
89 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
90 if (hoplimit == 0) {
91 struct net_device *dev = dst->dev;
92 struct inet6_dev *idev;
93
94 rcu_read_lock();
95 idev = __in6_dev_get(dev);
96 if (idev)
97 hoplimit = idev->cnf.hop_limit;
98 else
99 hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
100 rcu_read_unlock();
101 }
102 return hoplimit;
103}
104EXPORT_SYMBOL(ip6_dst_hoplimit);
105#endif
Cong Wang788787b2013-08-31 13:44:29 +0800106
107int __ip6_local_out(struct sk_buff *skb)
108{
109 int len;
110
111 len = skb->len - sizeof(struct ipv6hdr);
112 if (len > IPV6_MAXPLEN)
113 len = 0;
114 ipv6_hdr(skb)->payload_len = htons(len);
huizhangf6c20c52014-06-09 12:37:25 +0800115 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
Cong Wang788787b2013-08-31 13:44:29 +0800116
117 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
118 skb_dst(skb)->dev, dst_output);
119}
120EXPORT_SYMBOL_GPL(__ip6_local_out);
121
122int ip6_local_out(struct sk_buff *skb)
123{
124 int err;
125
126 err = __ip6_local_out(skb);
127 if (likely(err == 1))
128 err = dst_output(skb);
129
130 return err;
131}
132EXPORT_SYMBOL_GPL(ip6_local_out);