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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * IPv6 library code, needed by static components when full IPv6 support is
4 * not configured or static. These functions are needed by GSO/GRO implementation.
5 */
6#include <linux/export.h>
7#include <net/ip.h>
8#include <net/ipv6.h>
9#include <net/ip6_fib.h>
10#include <net/addrconf.h>
11#include <net/secure_seq.h>
12#include <linux/netfilter.h>
13
14static u32 __ipv6_select_ident(struct net *net,
15 const struct in6_addr *dst,
16 const struct in6_addr *src)
17{
18 u32 id;
19
20 do {
21 id = prandom_u32();
22 } while (!id);
23
24 return id;
25}
26
27/* This function exists only for tap drivers that must support broken
28 * clients requesting UFO without specifying an IPv6 fragment ID.
29 *
30 * This is similar to ipv6_select_ident() but we use an independent hash
31 * seed to limit information leakage.
32 *
33 * The network header must be set before calling this.
34 */
35__be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
36{
37 struct in6_addr buf[2];
38 struct in6_addr *addrs;
39 u32 id;
40
41 addrs = skb_header_pointer(skb,
42 skb_network_offset(skb) +
43 offsetof(struct ipv6hdr, saddr),
44 sizeof(buf), buf);
45 if (!addrs)
46 return 0;
47
48 id = __ipv6_select_ident(net, &addrs[1], &addrs[0]);
49 return htonl(id);
50}
51EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
52
53__be32 ipv6_select_ident(struct net *net,
54 const struct in6_addr *daddr,
55 const struct in6_addr *saddr)
56{
57 u32 id;
58
59 id = __ipv6_select_ident(net, daddr, saddr);
60 return htonl(id);
61}
62EXPORT_SYMBOL(ipv6_select_ident);
63
64int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
65{
66 unsigned int offset = sizeof(struct ipv6hdr);
67 unsigned int packet_len = skb_tail_pointer(skb) -
68 skb_network_header(skb);
69 int found_rhdr = 0;
70 *nexthdr = &ipv6_hdr(skb)->nexthdr;
71
72 while (offset <= packet_len) {
73 struct ipv6_opt_hdr *exthdr;
74
75 switch (**nexthdr) {
76
77 case NEXTHDR_HOP:
78 break;
79 case NEXTHDR_ROUTING:
80 found_rhdr = 1;
81 break;
82 case NEXTHDR_DEST:
83#if IS_ENABLED(CONFIG_IPV6_MIP6)
84 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
85 break;
86#endif
87 if (found_rhdr)
88 return offset;
89 break;
90 default:
91 return offset;
92 }
93
94 if (offset + sizeof(struct ipv6_opt_hdr) > packet_len)
95 return -EINVAL;
96
97 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
98 offset);
99 offset += ipv6_optlen(exthdr);
100 if (offset > IPV6_MAXPLEN)
101 return -EINVAL;
102 *nexthdr = &exthdr->nexthdr;
103 }
104
105 return -EINVAL;
106}
107EXPORT_SYMBOL(ip6_find_1stfragopt);
108
109#if IS_ENABLED(CONFIG_IPV6)
110int ip6_dst_hoplimit(struct dst_entry *dst)
111{
112 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
113 if (hoplimit == 0) {
114 struct net_device *dev = dst->dev;
115 struct inet6_dev *idev;
116
117 rcu_read_lock();
118 idev = __in6_dev_get(dev);
119 if (idev)
120 hoplimit = idev->cnf.hop_limit;
121 else
122 hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
123 rcu_read_unlock();
124 }
125 return hoplimit;
126}
127EXPORT_SYMBOL(ip6_dst_hoplimit);
128#endif
129
130int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
131{
132 int len;
133
134 len = skb->len - sizeof(struct ipv6hdr);
135 if (len > IPV6_MAXPLEN)
136 len = 0;
137 ipv6_hdr(skb)->payload_len = htons(len);
138 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
139
140 /* if egress device is enslaved to an L3 master device pass the
141 * skb to its handler for processing
142 */
143 skb = l3mdev_ip6_out(sk, skb);
144 if (unlikely(!skb))
145 return 0;
146
147 skb->protocol = htons(ETH_P_IPV6);
148
149 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
150 net, sk, skb, NULL, skb_dst(skb)->dev,
151 dst_output);
152}
153EXPORT_SYMBOL_GPL(__ip6_local_out);
154
155int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
156{
157 int err;
158
159 err = __ip6_local_out(net, sk, skb);
160 if (likely(err == 1))
161 err = dst_output(net, sk, skb);
162
163 return err;
164}
165EXPORT_SYMBOL_GPL(ip6_local_out);
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/ip.h>
7#include <net/ipv6.h>
8#include <net/ip6_fib.h>
9#include <net/addrconf.h>
10#include <net/secure_seq.h>
11#include <linux/netfilter.h>
12
13static u32 __ipv6_select_ident(struct net *net, u32 hashrnd,
14 const struct in6_addr *dst,
15 const struct in6_addr *src)
16{
17 u32 hash, id;
18
19 hash = __ipv6_addr_jhash(dst, hashrnd);
20 hash = __ipv6_addr_jhash(src, hash);
21 hash ^= net_hash_mix(net);
22
23 /* Treat id of 0 as unset and if we get 0 back from ip_idents_reserve,
24 * set the hight order instead thus minimizing possible future
25 * collisions.
26 */
27 id = ip_idents_reserve(hash, 1);
28 if (unlikely(!id))
29 id = 1 << 31;
30
31 return id;
32}
33
34/* This function exists only for tap drivers that must support broken
35 * clients requesting UFO without specifying an IPv6 fragment ID.
36 *
37 * This is similar to ipv6_select_ident() but we use an independent hash
38 * seed to limit information leakage.
39 *
40 * The network header must be set before calling this.
41 */
42__be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
43{
44 static u32 ip6_proxy_idents_hashrnd __read_mostly;
45 struct in6_addr buf[2];
46 struct in6_addr *addrs;
47 u32 id;
48
49 addrs = skb_header_pointer(skb,
50 skb_network_offset(skb) +
51 offsetof(struct ipv6hdr, saddr),
52 sizeof(buf), buf);
53 if (!addrs)
54 return 0;
55
56 net_get_random_once(&ip6_proxy_idents_hashrnd,
57 sizeof(ip6_proxy_idents_hashrnd));
58
59 id = __ipv6_select_ident(net, ip6_proxy_idents_hashrnd,
60 &addrs[1], &addrs[0]);
61 return htonl(id);
62}
63EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
64
65__be32 ipv6_select_ident(struct net *net,
66 const struct in6_addr *daddr,
67 const struct in6_addr *saddr)
68{
69 static u32 ip6_idents_hashrnd __read_mostly;
70 u32 id;
71
72 net_get_random_once(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd));
73
74 id = __ipv6_select_ident(net, ip6_idents_hashrnd, daddr, saddr);
75 return htonl(id);
76}
77EXPORT_SYMBOL(ipv6_select_ident);
78
79int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
80{
81 unsigned int offset = sizeof(struct ipv6hdr);
82 unsigned int packet_len = skb_tail_pointer(skb) -
83 skb_network_header(skb);
84 int found_rhdr = 0;
85 *nexthdr = &ipv6_hdr(skb)->nexthdr;
86
87 while (offset <= packet_len) {
88 struct ipv6_opt_hdr *exthdr;
89
90 switch (**nexthdr) {
91
92 case NEXTHDR_HOP:
93 break;
94 case NEXTHDR_ROUTING:
95 found_rhdr = 1;
96 break;
97 case NEXTHDR_DEST:
98#if IS_ENABLED(CONFIG_IPV6_MIP6)
99 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
100 break;
101#endif
102 if (found_rhdr)
103 return offset;
104 break;
105 default:
106 return offset;
107 }
108
109 if (offset + sizeof(struct ipv6_opt_hdr) > packet_len)
110 return -EINVAL;
111
112 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
113 offset);
114 offset += ipv6_optlen(exthdr);
115 if (offset > IPV6_MAXPLEN)
116 return -EINVAL;
117 *nexthdr = &exthdr->nexthdr;
118 }
119
120 return -EINVAL;
121}
122EXPORT_SYMBOL(ip6_find_1stfragopt);
123
124#if IS_ENABLED(CONFIG_IPV6)
125int ip6_dst_hoplimit(struct dst_entry *dst)
126{
127 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
128 if (hoplimit == 0) {
129 struct net_device *dev = dst->dev;
130 struct inet6_dev *idev;
131
132 rcu_read_lock();
133 idev = __in6_dev_get(dev);
134 if (idev)
135 hoplimit = idev->cnf.hop_limit;
136 else
137 hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
138 rcu_read_unlock();
139 }
140 return hoplimit;
141}
142EXPORT_SYMBOL(ip6_dst_hoplimit);
143#endif
144
145int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
146{
147 int len;
148
149 len = skb->len - sizeof(struct ipv6hdr);
150 if (len > IPV6_MAXPLEN)
151 len = 0;
152 ipv6_hdr(skb)->payload_len = htons(len);
153 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
154
155 /* if egress device is enslaved to an L3 master device pass the
156 * skb to its handler for processing
157 */
158 skb = l3mdev_ip6_out(sk, skb);
159 if (unlikely(!skb))
160 return 0;
161
162 skb->protocol = htons(ETH_P_IPV6);
163
164 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
165 net, sk, skb, NULL, skb_dst(skb)->dev,
166 dst_output);
167}
168EXPORT_SYMBOL_GPL(__ip6_local_out);
169
170int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
171{
172 int err;
173
174 err = __ip6_local_out(net, sk, skb);
175 if (likely(err == 1))
176 err = dst_output(net, sk, skb);
177
178 return err;
179}
180EXPORT_SYMBOL_GPL(ip6_local_out);