output_core.c revision 6dfac5c33620de7f5ecd9dd07e2e2bb6549c4d55 
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 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}
40EXPORT_SYMBOL(ipv6_select_ident);
41
42int 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}
81EXPORT_SYMBOL(ip6_find_1stfragopt);
82
83#if IS_ENABLED(CONFIG_IPV6)
84int 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}
101EXPORT_SYMBOL(ip6_dst_hoplimit);
102#endif
103
104int __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}
116EXPORT_SYMBOL_GPL(__ip6_local_out);
117
118int 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}
128EXPORT_SYMBOL_GPL(ip6_local_out);
129