LXR linux/net/ipv6/output

   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
   9void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt)
  10{
  11        static atomic_t ipv6_fragmentation_id;
  12        int old, new;
  13
  14#if IS_ENABLED(CONFIG_IPV6)
  15        if (rt && !(rt->dst.flags & DST_NOPEER)) {
  16                struct inet_peer *peer;
  17                struct net *net;
  18
  19                net = dev_net(rt->dst.dev);
  20                peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
  21                if (peer) {
  22                        fhdr->identification = htonl(inet_getid(peer, 0));
  23                        inet_putpeer(peer);
  24                        return;
  25                }
  26        }
  27#endif
  28        do {
  29                old = atomic_read(&ipv6_fragmentation_id);
  30                new = old + 1;
  31                if (!new)
  32                        new = 1;
  33        } while (atomic_cmpxchg(&ipv6_fragmentation_id, old, new) != old);
  34        fhdr->identification = htonl(new);
  35}
  36EXPORT_SYMBOL(ipv6_select_ident);
  37
  38int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
  39{
  40        u16 offset = sizeof(struct ipv6hdr);
  41        struct ipv6_opt_hdr *exthdr =
  42                                (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
  43        unsigned int packet_len = skb->tail - skb->network_header;
  44        int found_rhdr = 0;
  45        *nexthdr = &ipv6_hdr(skb)->nexthdr;
  46
  47        while (offset + 1 <= packet_len) {
  48
  49                switch (**nexthdr) {
  50
  51                case NEXTHDR_HOP:
  52                        break;
  53                case NEXTHDR_ROUTING:
  54                        found_rhdr = 1;
  55                        break;
  56                case NEXTHDR_DEST:
  57#if IS_ENABLED(CONFIG_IPV6_MIP6)
  58                        if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
  59                                break;
  60#endif
  61                        if (found_rhdr)
  62                                return offset;
  63                        break;
  64                default :
  65                        return offset;
  66                }
  67
  68                offset += ipv6_optlen(exthdr);
  69                *nexthdr = &exthdr->nexthdr;
  70                exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
  71                                                 offset);
  72        }
  73
  74        return offset;
  75}
  76EXPORT_SYMBOL(ip6_find_1stfragopt);
  77