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 #include <net/secure_seq.h>
  10
  11 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
  12 {
  13         u16 offset = sizeof(struct ipv6hdr);
  14         struct ipv6_opt_hdr *exthdr =
  15                                 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
  16         unsigned int packet_len = skb_tail_pointer(skb) -
  17                 skb_network_header(skb);
  18         int found_rhdr = 0;
  19         *nexthdr = &ipv6_hdr(skb)->nexthdr;
  20
  21         while (offset + 1 <= packet_len) {
  22
  23                 switch (**nexthdr) {
  24
  25                 case NEXTHDR_HOP:
  26                         break;
  27                 case NEXTHDR_ROUTING:
  28                         found_rhdr = 1;
  29                         break;
  30                 case NEXTHDR_DEST:
  31 #if IS_ENABLED(CONFIG_IPV6_MIP6)
  32                         if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
  33                                 break;
  34 #endif
  35                         if (found_rhdr)
  36                                 return offset;
  37                         break;
  38                 default :
  39                         return offset;
  40                 }
  41
  42                 offset += ipv6_optlen(exthdr);
  43                 *nexthdr = &exthdr->nexthdr;
  44                 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
  45                                                  offset);
  46         }
  47
  48         return offset;
  49 }
  50 EXPORT_SYMBOL(ip6_find_1stfragopt);
  51
  52 #if IS_ENABLED(CONFIG_IPV6)
  53 int ip6_dst_hoplimit(struct dst_entry *dst)
  54 {
  55         int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
  56         if (hoplimit == 0) {
  57                 struct net_device *dev = dst->dev;
  58                 struct inet6_dev *idev;
  59
  60                 rcu_read_lock();
  61                 idev = __in6_dev_get(dev);
  62                 if (idev)
  63                         hoplimit = idev->cnf.hop_limit;
  64                 else
  65                         hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
  66                 rcu_read_unlock();
  67         }
  68         return hoplimit;
  69 }
  70 EXPORT_SYMBOL(ip6_dst_hoplimit);
  71 #endif
  72
  73 int __ip6_local_out(struct sk_buff *skb)
  74 {
  75         int len;
  76
  77         len = skb->len - sizeof(struct ipv6hdr);
  78         if (len > IPV6_MAXPLEN)
  79                 len = 0;
  80         ipv6_hdr(skb)->payload_len = htons(len);
  81         IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
  82
  83         return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
  84                        skb_dst(skb)->dev, dst_output);
  85 }
  86 EXPORT_SYMBOL_GPL(__ip6_local_out);
  87
  88 int ip6_local_out(struct sk_buff *skb)
  89 {
  90         int err;
  91
  92         err = __ip6_local_out(skb);
  93         if (likely(err == 1))
  94                 err = dst_output(skb);
  95
  96         return err;
  97 }
  98 EXPORT_SYMBOL_GPL(ip6_local_out);