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