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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 const struct {
19 struct in6_addr dst;
20 struct in6_addr src;
21 } __aligned(SIPHASH_ALIGNMENT) combined = {
22 .dst = *dst,
23 .src = *src,
24 };
25 u32 hash, id;
26
27 /* Note the following code is not safe, but this is okay. */
28 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key)))
29 get_random_bytes(&net->ipv4.ip_id_key,
30 sizeof(net->ipv4.ip_id_key));
31
32 hash = siphash(&combined, sizeof(combined), &net->ipv4.ip_id_key);
33
34 /* Treat id of 0 as unset and if we get 0 back from ip_idents_reserve,
35 * set the hight order instead thus minimizing possible future
36 * collisions.
37 */
38 id = ip_idents_reserve(hash, 1);
39 if (unlikely(!id))
40 id = 1 << 31;
41
42 return id;
43}
44
45/* This function exists only for tap drivers that must support broken
46 * clients requesting UFO without specifying an IPv6 fragment ID.
47 *
48 * This is similar to ipv6_select_ident() but we use an independent hash
49 * seed to limit information leakage.
50 *
51 * The network header must be set before calling this.
52 */
53__be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
54{
55 struct in6_addr buf[2];
56 struct in6_addr *addrs;
57 u32 id;
58
59 addrs = skb_header_pointer(skb,
60 skb_network_offset(skb) +
61 offsetof(struct ipv6hdr, saddr),
62 sizeof(buf), buf);
63 if (!addrs)
64 return 0;
65
66 id = __ipv6_select_ident(net, &addrs[1], &addrs[0]);
67 return htonl(id);
68}
69EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
70
71__be32 ipv6_select_ident(struct net *net,
72 const struct in6_addr *daddr,
73 const struct in6_addr *saddr)
74{
75 u32 id;
76
77 id = __ipv6_select_ident(net, daddr, saddr);
78 return htonl(id);
79}
80EXPORT_SYMBOL(ipv6_select_ident);
81
82int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
83{
84 unsigned int offset = sizeof(struct ipv6hdr);
85 unsigned int packet_len = skb_tail_pointer(skb) -
86 skb_network_header(skb);
87 int found_rhdr = 0;
88 *nexthdr = &ipv6_hdr(skb)->nexthdr;
89
90 while (offset <= packet_len) {
91 struct ipv6_opt_hdr *exthdr;
92
93 switch (**nexthdr) {
94
95 case NEXTHDR_HOP:
96 break;
97 case NEXTHDR_ROUTING:
98 found_rhdr = 1;
99 break;
100 case NEXTHDR_DEST:
101#if IS_ENABLED(CONFIG_IPV6_MIP6)
102 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
103 break;
104#endif
105 if (found_rhdr)
106 return offset;
107 break;
108 default:
109 return offset;
110 }
111
112 if (offset + sizeof(struct ipv6_opt_hdr) > packet_len)
113 return -EINVAL;
114
115 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
116 offset);
117 offset += ipv6_optlen(exthdr);
118 if (offset > IPV6_MAXPLEN)
119 return -EINVAL;
120 *nexthdr = &exthdr->nexthdr;
121 }
122
123 return -EINVAL;
124}
125EXPORT_SYMBOL(ip6_find_1stfragopt);
126
127#if IS_ENABLED(CONFIG_IPV6)
128int ip6_dst_hoplimit(struct dst_entry *dst)
129{
130 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
131 if (hoplimit == 0) {
132 struct net_device *dev = dst->dev;
133 struct inet6_dev *idev;
134
135 rcu_read_lock();
136 idev = __in6_dev_get(dev);
137 if (idev)
138 hoplimit = idev->cnf.hop_limit;
139 else
140 hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
141 rcu_read_unlock();
142 }
143 return hoplimit;
144}
145EXPORT_SYMBOL(ip6_dst_hoplimit);
146#endif
147
148int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
149{
150 int len;
151
152 len = skb->len - sizeof(struct ipv6hdr);
153 if (len > IPV6_MAXPLEN)
154 len = 0;
155 ipv6_hdr(skb)->payload_len = htons(len);
156 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
157
158 /* if egress device is enslaved to an L3 master device pass the
159 * skb to its handler for processing
160 */
161 skb = l3mdev_ip6_out(sk, skb);
162 if (unlikely(!skb))
163 return 0;
164
165 skb->protocol = htons(ETH_P_IPV6);
166
167 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
168 net, sk, skb, NULL, skb_dst(skb)->dev,
169 dst_output);
170}
171EXPORT_SYMBOL_GPL(__ip6_local_out);
172
173int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
174{
175 int err;
176
177 err = __ip6_local_out(net, sk, skb);
178 if (likely(err == 1))
179 err = dst_output(net, sk, skb);
180
181 return err;
182}
183EXPORT_SYMBOL_GPL(ip6_local_out);
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 return get_random_u32_above(0);
19}
20
21/* This function exists only for tap drivers that must support broken
22 * clients requesting UFO without specifying an IPv6 fragment ID.
23 *
24 * This is similar to ipv6_select_ident() but we use an independent hash
25 * seed to limit information leakage.
26 *
27 * The network header must be set before calling this.
28 */
29__be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
30{
31 struct in6_addr buf[2];
32 struct in6_addr *addrs;
33 u32 id;
34
35 addrs = skb_header_pointer(skb,
36 skb_network_offset(skb) +
37 offsetof(struct ipv6hdr, saddr),
38 sizeof(buf), buf);
39 if (!addrs)
40 return 0;
41
42 id = __ipv6_select_ident(net, &addrs[1], &addrs[0]);
43 return htonl(id);
44}
45EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
46
47__be32 ipv6_select_ident(struct net *net,
48 const struct in6_addr *daddr,
49 const struct in6_addr *saddr)
50{
51 u32 id;
52
53 id = __ipv6_select_ident(net, daddr, saddr);
54 return htonl(id);
55}
56EXPORT_SYMBOL(ipv6_select_ident);
57
58int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
59{
60 unsigned int offset = sizeof(struct ipv6hdr);
61 unsigned int packet_len = skb_tail_pointer(skb) -
62 skb_network_header(skb);
63 int found_rhdr = 0;
64 *nexthdr = &ipv6_hdr(skb)->nexthdr;
65
66 while (offset <= packet_len) {
67 struct ipv6_opt_hdr *exthdr;
68
69 switch (**nexthdr) {
70
71 case NEXTHDR_HOP:
72 break;
73 case NEXTHDR_ROUTING:
74 found_rhdr = 1;
75 break;
76 case NEXTHDR_DEST:
77#if IS_ENABLED(CONFIG_IPV6_MIP6)
78 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
79 break;
80#endif
81 if (found_rhdr)
82 return offset;
83 break;
84 default:
85 return offset;
86 }
87
88 if (offset + sizeof(struct ipv6_opt_hdr) > packet_len)
89 return -EINVAL;
90
91 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
92 offset);
93 offset += ipv6_optlen(exthdr);
94 if (offset > IPV6_MAXPLEN)
95 return -EINVAL;
96 *nexthdr = &exthdr->nexthdr;
97 }
98
99 return -EINVAL;
100}
101EXPORT_SYMBOL(ip6_find_1stfragopt);
102
103#if IS_ENABLED(CONFIG_IPV6)
104int ip6_dst_hoplimit(struct dst_entry *dst)
105{
106 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
107 if (hoplimit == 0) {
108 struct net_device *dev = dst->dev;
109 struct inet6_dev *idev;
110
111 rcu_read_lock();
112 idev = __in6_dev_get(dev);
113 if (idev)
114 hoplimit = READ_ONCE(idev->cnf.hop_limit);
115 else
116 hoplimit = READ_ONCE(dev_net(dev)->ipv6.devconf_all->hop_limit);
117 rcu_read_unlock();
118 }
119 return hoplimit;
120}
121EXPORT_SYMBOL(ip6_dst_hoplimit);
122#endif
123
124int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
125{
126 int len;
127
128 len = skb->len - sizeof(struct ipv6hdr);
129 if (len > IPV6_MAXPLEN)
130 len = 0;
131 ipv6_hdr(skb)->payload_len = htons(len);
132 IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
133
134 /* if egress device is enslaved to an L3 master device pass the
135 * skb to its handler for processing
136 */
137 skb = l3mdev_ip6_out(sk, skb);
138 if (unlikely(!skb))
139 return 0;
140
141 skb->protocol = htons(ETH_P_IPV6);
142
143 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
144 net, sk, skb, NULL, skb_dst(skb)->dev,
145 dst_output);
146}
147EXPORT_SYMBOL_GPL(__ip6_local_out);
148
149int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
150{
151 int err;
152
153 err = __ip6_local_out(net, sk, skb);
154 if (likely(err == 1))
155 err = dst_output(net, sk, skb);
156
157 return err;
158}
159EXPORT_SYMBOL_GPL(ip6_local_out);