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
 11void 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}
 35EXPORT_SYMBOL(ipv6_select_ident);
 36
 37int 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}
 76EXPORT_SYMBOL(ip6_find_1stfragopt);
 77
 78#if IS_ENABLED(CONFIG_IPV6)
 79int 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}
 96EXPORT_SYMBOL(ip6_dst_hoplimit);
 97#endif
 98
 99int __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}
111EXPORT_SYMBOL_GPL(__ip6_local_out);
112
113int 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}
123EXPORT_SYMBOL_GPL(ip6_local_out);