xref: /openbmc/linux/net/ipv6/output_core.c (revision d2999e1b)
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 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
12 {
13 	u16 offset = sizeof(struct ipv6hdr);
14 	struct ipv6_opt_hdr *exthdr =
15 				(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
16 	unsigned int packet_len = skb_tail_pointer(skb) -
17 		skb_network_header(skb);
18 	int found_rhdr = 0;
19 	*nexthdr = &ipv6_hdr(skb)->nexthdr;
20 
21 	while (offset + 1 <= packet_len) {
22 
23 		switch (**nexthdr) {
24 
25 		case NEXTHDR_HOP:
26 			break;
27 		case NEXTHDR_ROUTING:
28 			found_rhdr = 1;
29 			break;
30 		case NEXTHDR_DEST:
31 #if IS_ENABLED(CONFIG_IPV6_MIP6)
32 			if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
33 				break;
34 #endif
35 			if (found_rhdr)
36 				return offset;
37 			break;
38 		default :
39 			return offset;
40 		}
41 
42 		offset += ipv6_optlen(exthdr);
43 		*nexthdr = &exthdr->nexthdr;
44 		exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
45 						 offset);
46 	}
47 
48 	return offset;
49 }
50 EXPORT_SYMBOL(ip6_find_1stfragopt);
51 
52 #if IS_ENABLED(CONFIG_IPV6)
53 int ip6_dst_hoplimit(struct dst_entry *dst)
54 {
55 	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
56 	if (hoplimit == 0) {
57 		struct net_device *dev = dst->dev;
58 		struct inet6_dev *idev;
59 
60 		rcu_read_lock();
61 		idev = __in6_dev_get(dev);
62 		if (idev)
63 			hoplimit = idev->cnf.hop_limit;
64 		else
65 			hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
66 		rcu_read_unlock();
67 	}
68 	return hoplimit;
69 }
70 EXPORT_SYMBOL(ip6_dst_hoplimit);
71 #endif
72 
73 int __ip6_local_out(struct sk_buff *skb)
74 {
75 	int len;
76 
77 	len = skb->len - sizeof(struct ipv6hdr);
78 	if (len > IPV6_MAXPLEN)
79 		len = 0;
80 	ipv6_hdr(skb)->payload_len = htons(len);
81 	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
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);
99