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
   9
  10 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
  11 {
  12         u16 offset = sizeof(struct ipv6hdr);
  13         struct ipv6_opt_hdr *exthdr =
  14                                 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
  15         unsigned int packet_len = skb->tail - skb->network_header;
  16         int found_rhdr = 0;
  17         *nexthdr = &ipv6_hdr(skb)->nexthdr;
  18
  19         while (offset + 1 <= packet_len) {
  20
  21                 switch (**nexthdr) {
  22
  23                 case NEXTHDR_HOP:
  24                         break;
  25                 case NEXTHDR_ROUTING:
  26                         found_rhdr = 1;
  27                         break;
  28                 case NEXTHDR_DEST:
  29 #if IS_ENABLED(CONFIG_IPV6_MIP6)
  30                         if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
  31                                 break;
  32 #endif
  33                         if (found_rhdr)
  34                                 return offset;
  35                         break;
  36                 default :
  37                         return offset;
  38                 }
  39
  40                 offset += ipv6_optlen(exthdr);
  41                 *nexthdr = &exthdr->nexthdr;
  42                 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
  43                                                  offset);
  44         }
  45
  46         return offset;
  47 }
  48 EXPORT_SYMBOL(ip6_find_1stfragopt);