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 old, new; 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 do { 30 old = atomic_read(&ipv6_fragmentation_id); 31 new = old + 1; 32 if (!new) 33 new = 1; 34 } while (atomic_cmpxchg(&ipv6_fragmentation_id, old, new) != old); 35 36 addr = rt->rt6i_dst.addr; 37 addr.s6_addr32[0] ^= (__force __be32)new; 38 fhdr->identification = htonl(secure_ipv6_id(addr.s6_addr32)); 39 } 40 EXPORT_SYMBOL(ipv6_select_ident); 41 42 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) 43 { 44 u16 offset = sizeof(struct ipv6hdr); 45 struct ipv6_opt_hdr *exthdr = 46 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1); 47 unsigned int packet_len = skb_tail_pointer(skb) - 48 skb_network_header(skb); 49 int found_rhdr = 0; 50 *nexthdr = &ipv6_hdr(skb)->nexthdr; 51 52 while (offset + 1 <= packet_len) { 53 54 switch (**nexthdr) { 55 56 case NEXTHDR_HOP: 57 break; 58 case NEXTHDR_ROUTING: 59 found_rhdr = 1; 60 break; 61 case NEXTHDR_DEST: 62 #if IS_ENABLED(CONFIG_IPV6_MIP6) 63 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) 64 break; 65 #endif 66 if (found_rhdr) 67 return offset; 68 break; 69 default : 70 return offset; 71 } 72 73 offset += ipv6_optlen(exthdr); 74 *nexthdr = &exthdr->nexthdr; 75 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) + 76 offset); 77 } 78 79 return offset; 80 } 81 EXPORT_SYMBOL(ip6_find_1stfragopt); 82 83 #if IS_ENABLED(CONFIG_IPV6) 84 int ip6_dst_hoplimit(struct dst_entry *dst) 85 { 86 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 87 if (hoplimit == 0) { 88 struct net_device *dev = dst->dev; 89 struct inet6_dev *idev; 90 91 rcu_read_lock(); 92 idev = __in6_dev_get(dev); 93 if (idev) 94 hoplimit = idev->cnf.hop_limit; 95 else 96 hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit; 97 rcu_read_unlock(); 98 } 99 return hoplimit; 100 } 101 EXPORT_SYMBOL(ip6_dst_hoplimit); 102 #endif 103 104 int __ip6_local_out(struct sk_buff *skb) 105 { 106 int len; 107 108 len = skb->len - sizeof(struct ipv6hdr); 109 if (len > IPV6_MAXPLEN) 110 len = 0; 111 ipv6_hdr(skb)->payload_len = htons(len); 112 113 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, 114 skb_dst(skb)->dev, dst_output); 115 } 116 EXPORT_SYMBOL_GPL(__ip6_local_out); 117 118 int ip6_local_out(struct sk_buff *skb) 119 { 120 int err; 121 122 err = __ip6_local_out(skb); 123 if (likely(err == 1)) 124 err = dst_output(skb); 125 126 return err; 127 } 128 EXPORT_SYMBOL_GPL(ip6_local_out); 129