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.
5 #include <linux/export.h>
8 #include <net/ip6_fib.h>
9 #include <net/addrconf.h>
10 #include <net/secure_seq.h>
12 /* This function exists only for tap drivers that must support broken
13 * clients requesting UFO without specifying an IPv6 fragment ID.
15 * This is similar to ipv6_select_ident() but we use an independent hash
16 * seed to limit information leakage.
18 * The network header must be set before calling this.
20 void ipv6_proxy_select_ident(struct sk_buff
*skb
)
22 static u32 ip6_proxy_idents_hashrnd __read_mostly
;
23 struct in6_addr buf
[2];
24 struct in6_addr
*addrs
;
27 addrs
= skb_header_pointer(skb
,
28 skb_network_offset(skb
) +
29 offsetof(struct ipv6hdr
, saddr
),
34 net_get_random_once(&ip6_proxy_idents_hashrnd
,
35 sizeof(ip6_proxy_idents_hashrnd
));
37 hash
= __ipv6_addr_jhash(&addrs
[1], ip6_proxy_idents_hashrnd
);
38 hash
= __ipv6_addr_jhash(&addrs
[0], hash
);
40 id
= ip_idents_reserve(hash
, 1);
41 skb_shinfo(skb
)->ip6_frag_id
= htonl(id
);
43 EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident
);
45 int ip6_find_1stfragopt(struct sk_buff
*skb
, u8
**nexthdr
)
47 u16 offset
= sizeof(struct ipv6hdr
);
48 struct ipv6_opt_hdr
*exthdr
=
49 (struct ipv6_opt_hdr
*)(ipv6_hdr(skb
) + 1);
50 unsigned int packet_len
= skb_tail_pointer(skb
) -
51 skb_network_header(skb
);
53 *nexthdr
= &ipv6_hdr(skb
)->nexthdr
;
55 while (offset
+ 1 <= packet_len
) {
65 #if IS_ENABLED(CONFIG_IPV6_MIP6)
66 if (ipv6_find_tlv(skb
, offset
, IPV6_TLV_HAO
) >= 0)
76 offset
+= ipv6_optlen(exthdr
);
77 *nexthdr
= &exthdr
->nexthdr
;
78 exthdr
= (struct ipv6_opt_hdr
*)(skb_network_header(skb
) +
84 EXPORT_SYMBOL(ip6_find_1stfragopt
);
86 #if IS_ENABLED(CONFIG_IPV6)
87 int ip6_dst_hoplimit(struct dst_entry
*dst
)
89 int hoplimit
= dst_metric_raw(dst
, RTAX_HOPLIMIT
);
91 struct net_device
*dev
= dst
->dev
;
92 struct inet6_dev
*idev
;
95 idev
= __in6_dev_get(dev
);
97 hoplimit
= idev
->cnf
.hop_limit
;
99 hoplimit
= dev_net(dev
)->ipv6
.devconf_all
->hop_limit
;
104 EXPORT_SYMBOL(ip6_dst_hoplimit
);
107 int __ip6_local_out(struct sk_buff
*skb
)
111 len
= skb
->len
- sizeof(struct ipv6hdr
);
112 if (len
> IPV6_MAXPLEN
)
114 ipv6_hdr(skb
)->payload_len
= htons(len
);
115 IP6CB(skb
)->nhoff
= offsetof(struct ipv6hdr
, nexthdr
);
117 return nf_hook(NFPROTO_IPV6
, NF_INET_LOCAL_OUT
, skb
, NULL
,
118 skb_dst(skb
)->dev
, dst_output
);
120 EXPORT_SYMBOL_GPL(__ip6_local_out
);
122 int ip6_local_out(struct sk_buff
*skb
)
126 err
= __ip6_local_out(skb
);
127 if (likely(err
== 1))
128 err
= dst_output(skb
);
132 EXPORT_SYMBOL_GPL(ip6_local_out
);