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 void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt)
  12 {
  13         static atomic_t ipv6_fragmentation_id;
  14         struct in6_addr addr;
  15         int ident;
  16
  17 #if IS_ENABLED(CONFIG_IPV6)
  18         struct inet_peer *peer;
  19         struct net *net;
  20
  21         net = dev_net(rt->dst.dev);
  22         peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
  23         if (peer) {
  24                 fhdr->identification = htonl(inet_getid(peer, 0));
  25                 inet_putpeer(peer);
  26                 return;
  27         }
  28 #endif
  29         ident = atomic_inc_return(&ipv6_fragmentation_id);
  30
  31         addr = rt->rt6i_dst.addr;
  32         addr.s6_addr32[0] ^= (__force __be32)ident;
  33         fhdr->identification = htonl(secure_ipv6_id(addr.s6_addr32));
  34 }
  35 EXPORT_SYMBOL(ipv6_select_ident);
  36
  37 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
  38 {
  39         u16 offset = sizeof(struct ipv6hdr);
  40         struct ipv6_opt_hdr *exthdr =
  41                                 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
  42         unsigned int packet_len = skb_tail_pointer(skb) -
  43                 skb_network_header(skb);
  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 }
  76 EXPORT_SYMBOL(ip6_find_1stfragopt);
  77
  78 #if IS_ENABLED(CONFIG_IPV6)
  79 int ip6_dst_hoplimit(struct dst_entry *dst)
  80 {
  81         int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
  82         if (hoplimit == 0) {
  83                 struct net_device *dev = dst->dev;
  84                 struct inet6_dev *idev;
  85
  86                 rcu_read_lock();
  87                 idev = __in6_dev_get(dev);
  88                 if (idev)
  89                         hoplimit = idev->cnf.hop_limit;
  90                 else
  91                         hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
  92                 rcu_read_unlock();
  93         }
  94         return hoplimit;
  95 }
  96 EXPORT_SYMBOL(ip6_dst_hoplimit);
  97 #endif
  98
  99 int __ip6_local_out(struct sk_buff *skb)
 100 {
 101         int len;
 102
 103         len = skb->len - sizeof(struct ipv6hdr);
 104         if (len > IPV6_MAXPLEN)
 105                 len = 0;
 106         ipv6_hdr(skb)->payload_len = htons(len);
 107
 108         return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
 109                        skb_dst(skb)->dev, dst_output);
 110 }
 111 EXPORT_SYMBOL_GPL(__ip6_local_out);
 112
 113 int ip6_local_out(struct sk_buff *skb)
 114 {
 115         int err;
 116
 117         err = __ip6_local_out(skb);
 118         if (likely(err == 1))
 119                 err = dst_output(skb);
 120
 121         return err;
 122 }
 123 EXPORT_SYMBOL_GPL(ip6_local_out);