ipv6: move ip6_dst_hoplimit() into core kernel
[karo-tx-linux.git] / net / ipv6 / output_core.c
1 /*
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>
6 #include <net/ipv6.h>
7 #include <net/ip6_fib.h>
8 #include <net/addrconf.h>
9
10 void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt)
11 {
12         static atomic_t ipv6_fragmentation_id;
13         int old, new;
14
15 #if IS_ENABLED(CONFIG_IPV6)
16         if (rt && !(rt->dst.flags & DST_NOPEER)) {
17                 struct inet_peer *peer;
18                 struct net *net;
19
20                 net = dev_net(rt->dst.dev);
21                 peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
22                 if (peer) {
23                         fhdr->identification = htonl(inet_getid(peer, 0));
24                         inet_putpeer(peer);
25                         return;
26                 }
27         }
28 #endif
29         do {
30                 old = atomic_read(&ipv6_fragmentation_id);
31                 new = old + 1;
32                 if (!new)
33                         new = 1;
34         } while (atomic_cmpxchg(&ipv6_fragmentation_id, old, new) != old);
35         fhdr->identification = htonl(new);
36 }
37 EXPORT_SYMBOL(ipv6_select_ident);
38
39 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
40 {
41         u16 offset = sizeof(struct ipv6hdr);
42         struct ipv6_opt_hdr *exthdr =
43                                 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
44         unsigned int packet_len = skb_tail_pointer(skb) -
45                 skb_network_header(skb);
46         int found_rhdr = 0;
47         *nexthdr = &ipv6_hdr(skb)->nexthdr;
48
49         while (offset + 1 <= packet_len) {
50
51                 switch (**nexthdr) {
52
53                 case NEXTHDR_HOP:
54                         break;
55                 case NEXTHDR_ROUTING:
56                         found_rhdr = 1;
57                         break;
58                 case NEXTHDR_DEST:
59 #if IS_ENABLED(CONFIG_IPV6_MIP6)
60                         if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
61                                 break;
62 #endif
63                         if (found_rhdr)
64                                 return offset;
65                         break;
66                 default :
67                         return offset;
68                 }
69
70                 offset += ipv6_optlen(exthdr);
71                 *nexthdr = &exthdr->nexthdr;
72                 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
73                                                  offset);
74         }
75
76         return offset;
77 }
78 EXPORT_SYMBOL(ip6_find_1stfragopt);
79
80 #if IS_ENABLED(CONFIG_IPV6)
81 int ip6_dst_hoplimit(struct dst_entry *dst)
82 {
83         int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
84         if (hoplimit == 0) {
85                 struct net_device *dev = dst->dev;
86                 struct inet6_dev *idev;
87
88                 rcu_read_lock();
89                 idev = __in6_dev_get(dev);
90                 if (idev)
91                         hoplimit = idev->cnf.hop_limit;
92                 else
93                         hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
94                 rcu_read_unlock();
95         }
96         return hoplimit;
97 }
98 EXPORT_SYMBOL(ip6_dst_hoplimit);
99 #endif