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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
aa3463d6 TH |
2 | #include <linux/module.h> |
3 | #include <linux/errno.h> | |
4 | #include <linux/socket.h> | |
5 | #include <linux/skbuff.h> | |
6 | #include <linux/ip.h> | |
7 | #include <linux/udp.h> | |
b8a51b38 | 8 | #include <linux/icmpv6.h> |
aa3463d6 TH |
9 | #include <linux/types.h> |
10 | #include <linux/kernel.h> | |
11 | #include <net/fou.h> | |
12 | #include <net/ip.h> | |
13 | #include <net/ip6_tunnel.h> | |
14 | #include <net/ip6_checksum.h> | |
15 | #include <net/protocol.h> | |
16 | #include <net/udp.h> | |
17 | #include <net/udp_tunnel.h> | |
18 | ||
9dc621af | 19 | #if IS_ENABLED(CONFIG_IPV6_FOU_TUNNEL) |
20 | ||
aa3463d6 TH |
21 | static void fou6_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e, |
22 | struct flowi6 *fl6, u8 *protocol, __be16 sport) | |
23 | { | |
24 | struct udphdr *uh; | |
25 | ||
26 | skb_push(skb, sizeof(struct udphdr)); | |
27 | skb_reset_transport_header(skb); | |
28 | ||
29 | uh = udp_hdr(skb); | |
30 | ||
31 | uh->dest = e->dport; | |
32 | uh->source = sport; | |
33 | uh->len = htons(skb->len); | |
34 | udp6_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM6), skb, | |
35 | &fl6->saddr, &fl6->daddr, skb->len); | |
36 | ||
37 | *protocol = IPPROTO_UDP; | |
38 | } | |
39 | ||
9dc621af | 40 | static int fou6_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, |
41 | u8 *protocol, struct flowi6 *fl6) | |
aa3463d6 TH |
42 | { |
43 | __be16 sport; | |
44 | int err; | |
45 | int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM6 ? | |
46 | SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL; | |
47 | ||
48 | err = __fou_build_header(skb, e, protocol, &sport, type); | |
49 | if (err) | |
50 | return err; | |
51 | ||
52 | fou6_build_udp(skb, e, fl6, protocol, sport); | |
53 | ||
54 | return 0; | |
55 | } | |
aa3463d6 | 56 | |
9dc621af | 57 | static int gue6_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, |
58 | u8 *protocol, struct flowi6 *fl6) | |
aa3463d6 TH |
59 | { |
60 | __be16 sport; | |
61 | int err; | |
62 | int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM6 ? | |
63 | SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL; | |
64 | ||
65 | err = __gue_build_header(skb, e, protocol, &sport, type); | |
66 | if (err) | |
67 | return err; | |
68 | ||
69 | fou6_build_udp(skb, e, fl6, protocol, sport); | |
70 | ||
71 | return 0; | |
72 | } | |
aa3463d6 | 73 | |
b8a51b38 SB |
74 | static int gue6_err_proto_handler(int proto, struct sk_buff *skb, |
75 | struct inet6_skb_parm *opt, | |
5de362df | 76 | u8 type, u8 code, int offset, __be32 info) |
b8a51b38 SB |
77 | { |
78 | const struct inet6_protocol *ipprot; | |
79 | ||
80 | ipprot = rcu_dereference(inet6_protos[proto]); | |
81 | if (ipprot && ipprot->err_handler) { | |
82 | if (!ipprot->err_handler(skb, opt, type, code, offset, info)) | |
83 | return 0; | |
84 | } | |
85 | ||
86 | return -ENOENT; | |
87 | } | |
88 | ||
89 | static int gue6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, | |
90 | u8 type, u8 code, int offset, __be32 info) | |
91 | { | |
92 | int transport_offset = skb_transport_offset(skb); | |
93 | struct guehdr *guehdr; | |
26fc181e | 94 | size_t len, optlen; |
b8a51b38 SB |
95 | int ret; |
96 | ||
26fc181e | 97 | len = sizeof(struct udphdr) + sizeof(struct guehdr); |
5355ed63 | 98 | if (!pskb_may_pull(skb, transport_offset + len)) |
b8a51b38 SB |
99 | return -EINVAL; |
100 | ||
101 | guehdr = (struct guehdr *)&udp_hdr(skb)[1]; | |
102 | ||
103 | switch (guehdr->version) { | |
104 | case 0: /* Full GUE header present */ | |
105 | break; | |
106 | case 1: { | |
107 | /* Direct encasulation of IPv4 or IPv6 */ | |
108 | skb_set_transport_header(skb, -(int)sizeof(struct icmp6hdr)); | |
109 | ||
110 | switch (((struct iphdr *)guehdr)->version) { | |
111 | case 4: | |
112 | ret = gue6_err_proto_handler(IPPROTO_IPIP, skb, opt, | |
113 | type, code, offset, info); | |
114 | goto out; | |
115 | case 6: | |
116 | ret = gue6_err_proto_handler(IPPROTO_IPV6, skb, opt, | |
117 | type, code, offset, info); | |
118 | goto out; | |
119 | default: | |
120 | ret = -EOPNOTSUPP; | |
121 | goto out; | |
122 | } | |
123 | } | |
124 | default: /* Undefined version */ | |
125 | return -EOPNOTSUPP; | |
126 | } | |
127 | ||
128 | if (guehdr->control) | |
129 | return -ENOENT; | |
130 | ||
131 | optlen = guehdr->hlen << 2; | |
132 | ||
5355ed63 | 133 | if (!pskb_may_pull(skb, transport_offset + len + optlen)) |
26fc181e ED |
134 | return -EINVAL; |
135 | ||
136 | guehdr = (struct guehdr *)&udp_hdr(skb)[1]; | |
b8a51b38 SB |
137 | if (validate_gue_flags(guehdr, optlen)) |
138 | return -EINVAL; | |
139 | ||
44039e00 SB |
140 | /* Handling exceptions for direct UDP encapsulation in GUE would lead to |
141 | * recursion. Besides, this kind of encapsulation can't even be | |
142 | * configured currently. Discard this. | |
143 | */ | |
144 | if (guehdr->proto_ctype == IPPROTO_UDP || | |
145 | guehdr->proto_ctype == IPPROTO_UDPLITE) | |
146 | return -EOPNOTSUPP; | |
147 | ||
b8a51b38 SB |
148 | skb_set_transport_header(skb, -(int)sizeof(struct icmp6hdr)); |
149 | ret = gue6_err_proto_handler(guehdr->proto_ctype, skb, | |
150 | opt, type, code, offset, info); | |
151 | ||
152 | out: | |
153 | skb_set_transport_header(skb, transport_offset); | |
154 | return ret; | |
155 | } | |
156 | ||
157 | ||
aa3463d6 TH |
158 | static const struct ip6_tnl_encap_ops fou_ip6tun_ops = { |
159 | .encap_hlen = fou_encap_hlen, | |
160 | .build_header = fou6_build_header, | |
b8a51b38 | 161 | .err_handler = gue6_err, |
aa3463d6 TH |
162 | }; |
163 | ||
164 | static const struct ip6_tnl_encap_ops gue_ip6tun_ops = { | |
165 | .encap_hlen = gue_encap_hlen, | |
166 | .build_header = gue6_build_header, | |
b8a51b38 | 167 | .err_handler = gue6_err, |
aa3463d6 TH |
168 | }; |
169 | ||
170 | static int ip6_tnl_encap_add_fou_ops(void) | |
171 | { | |
172 | int ret; | |
173 | ||
174 | ret = ip6_tnl_encap_add_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU); | |
175 | if (ret < 0) { | |
176 | pr_err("can't add fou6 ops\n"); | |
177 | return ret; | |
178 | } | |
179 | ||
180 | ret = ip6_tnl_encap_add_ops(&gue_ip6tun_ops, TUNNEL_ENCAP_GUE); | |
181 | if (ret < 0) { | |
182 | pr_err("can't add gue6 ops\n"); | |
183 | ip6_tnl_encap_del_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU); | |
184 | return ret; | |
185 | } | |
186 | ||
187 | return 0; | |
188 | } | |
189 | ||
190 | static void ip6_tnl_encap_del_fou_ops(void) | |
191 | { | |
192 | ip6_tnl_encap_del_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU); | |
193 | ip6_tnl_encap_del_ops(&gue_ip6tun_ops, TUNNEL_ENCAP_GUE); | |
194 | } | |
195 | ||
196 | #else | |
197 | ||
198 | static int ip6_tnl_encap_add_fou_ops(void) | |
199 | { | |
200 | return 0; | |
201 | } | |
202 | ||
203 | static void ip6_tnl_encap_del_fou_ops(void) | |
204 | { | |
205 | } | |
206 | ||
207 | #endif | |
208 | ||
209 | static int __init fou6_init(void) | |
210 | { | |
211 | int ret; | |
212 | ||
213 | ret = ip6_tnl_encap_add_fou_ops(); | |
214 | ||
215 | return ret; | |
216 | } | |
217 | ||
218 | static void __exit fou6_fini(void) | |
219 | { | |
220 | ip6_tnl_encap_del_fou_ops(); | |
221 | } | |
222 | ||
223 | module_init(fou6_init); | |
224 | module_exit(fou6_fini); | |
225 | MODULE_AUTHOR("Tom Herbert <therbert@google.com>"); | |
226 | MODULE_LICENSE("GPL"); |