1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/errno.h>
3 #include <linux/ip.h>
4 #include <linux/kernel.h>
5 #include <linux/module.h>
6 #include <linux/skbuff.h>
7 #include <linux/socket.h>
8 #include <linux/types.h>
9 #include <net/checksum.h>
10 #include <net/dst_cache.h>
11 #include <net/ip.h>
12 #include <net/ip6_fib.h>
13 #include <net/ip6_route.h>
14 #include <net/lwtunnel.h>
15 #include <net/protocol.h>
16 #include <uapi/linux/ila.h>
17 #include "ila.h"
18
19 struct ila_lwt {
20 struct ila_params p;
21 struct dst_cache dst_cache;
22 u32 connected : 1;
23 u32 lwt_output : 1;
24 };
25
ila_lwt_lwtunnel(struct lwtunnel_state * lwt)26 static inline struct ila_lwt *ila_lwt_lwtunnel(
27 struct lwtunnel_state *lwt)
28 {
29 return (struct ila_lwt *)lwt->data;
30 }
31
ila_params_lwtunnel(struct lwtunnel_state * lwt)32 static inline struct ila_params *ila_params_lwtunnel(
33 struct lwtunnel_state *lwt)
34 {
35 return &ila_lwt_lwtunnel(lwt)->p;
36 }
37
ila_output(struct net * net,struct sock * sk,struct sk_buff * skb)38 static int ila_output(struct net *net, struct sock *sk, struct sk_buff *skb)
39 {
40 struct dst_entry *orig_dst = skb_dst(skb);
41 struct rt6_info *rt = (struct rt6_info *)orig_dst;
42 struct ila_lwt *ilwt = ila_lwt_lwtunnel(orig_dst->lwtstate);
43 struct dst_entry *dst;
44 int err = -EINVAL;
45
46 if (skb->protocol != htons(ETH_P_IPV6))
47 goto drop;
48
49 if (ilwt->lwt_output)
50 ila_update_ipv6_locator(skb,
51 ila_params_lwtunnel(orig_dst->lwtstate),
52 true);
53
54 if (rt->rt6i_flags & (RTF_GATEWAY | RTF_CACHE)) {
55 /* Already have a next hop address in route, no need for
56 * dest cache route.
57 */
58 return orig_dst->lwtstate->orig_output(net, sk, skb);
59 }
60
61 dst = dst_cache_get(&ilwt->dst_cache);
62 if (unlikely(!dst)) {
63 struct ipv6hdr *ip6h = ipv6_hdr(skb);
64 struct flowi6 fl6;
65
66 /* Lookup a route for the new destination. Take into
67 * account that the base route may already have a gateway.
68 */
69
70 memset(&fl6, 0, sizeof(fl6));
71 fl6.flowi6_oif = orig_dst->dev->ifindex;
72 fl6.flowi6_iif = LOOPBACK_IFINDEX;
73 fl6.daddr = *rt6_nexthop((struct rt6_info *)orig_dst,
74 &ip6h->daddr);
75
76 dst = ip6_route_output(net, NULL, &fl6);
77 if (dst->error) {
78 err = -EHOSTUNREACH;
79 dst_release(dst);
80 goto drop;
81 }
82
83 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
84 if (IS_ERR(dst)) {
85 err = PTR_ERR(dst);
86 goto drop;
87 }
88
89 if (ilwt->connected)
90 dst_cache_set_ip6(&ilwt->dst_cache, dst, &fl6.saddr);
91 }
92
93 skb_dst_set(skb, dst);
94 return dst_output(net, sk, skb);
95
96 drop:
97 kfree_skb(skb);
98 return err;
99 }
100
ila_input(struct sk_buff * skb)101 static int ila_input(struct sk_buff *skb)
102 {
103 struct dst_entry *dst = skb_dst(skb);
104 struct ila_lwt *ilwt = ila_lwt_lwtunnel(dst->lwtstate);
105
106 if (skb->protocol != htons(ETH_P_IPV6))
107 goto drop;
108
109 if (!ilwt->lwt_output)
110 ila_update_ipv6_locator(skb,
111 ila_params_lwtunnel(dst->lwtstate),
112 false);
113
114 return dst->lwtstate->orig_input(skb);
115
116 drop:
117 kfree_skb(skb);
118 return -EINVAL;
119 }
120
121 static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = {
122 [ILA_ATTR_LOCATOR] = { .type = NLA_U64, },
123 [ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, },
124 [ILA_ATTR_IDENT_TYPE] = { .type = NLA_U8, },
125 [ILA_ATTR_HOOK_TYPE] = { .type = NLA_U8, },
126 };
127
ila_build_state(struct net * net,struct nlattr * nla,unsigned int family,const void * cfg,struct lwtunnel_state ** ts,struct netlink_ext_ack * extack)128 static int ila_build_state(struct net *net, struct nlattr *nla,
129 unsigned int family, const void *cfg,
130 struct lwtunnel_state **ts,
131 struct netlink_ext_ack *extack)
132 {
133 struct ila_lwt *ilwt;
134 struct ila_params *p;
135 struct nlattr *tb[ILA_ATTR_MAX + 1];
136 struct lwtunnel_state *newts;
137 const struct fib6_config *cfg6 = cfg;
138 struct ila_addr *iaddr;
139 u8 ident_type = ILA_ATYPE_USE_FORMAT;
140 u8 hook_type = ILA_HOOK_ROUTE_OUTPUT;
141 u8 csum_mode = ILA_CSUM_NO_ACTION;
142 bool lwt_output = true;
143 u8 eff_ident_type;
144 int ret;
145
146 if (family != AF_INET6)
147 return -EINVAL;
148
149 ret = nla_parse_nested_deprecated(tb, ILA_ATTR_MAX, nla,
150 ila_nl_policy, extack);
151 if (ret < 0)
152 return ret;
153
154 if (!tb[ILA_ATTR_LOCATOR])
155 return -EINVAL;
156
157 iaddr = (struct ila_addr *)&cfg6->fc_dst;
158
159 if (tb[ILA_ATTR_IDENT_TYPE])
160 ident_type = nla_get_u8(tb[ILA_ATTR_IDENT_TYPE]);
161
162 if (ident_type == ILA_ATYPE_USE_FORMAT) {
163 /* Infer identifier type from type field in formatted
164 * identifier.
165 */
166
167 if (cfg6->fc_dst_len < 8 * sizeof(struct ila_locator) + 3) {
168 /* Need to have full locator and at least type field
169 * included in destination
170 */
171 return -EINVAL;
172 }
173
174 eff_ident_type = iaddr->ident.type;
175 } else {
176 eff_ident_type = ident_type;
177 }
178
179 switch (eff_ident_type) {
180 case ILA_ATYPE_IID:
181 /* Don't allow ILA for IID type */
182 return -EINVAL;
183 case ILA_ATYPE_LUID:
184 break;
185 case ILA_ATYPE_VIRT_V4:
186 case ILA_ATYPE_VIRT_UNI_V6:
187 case ILA_ATYPE_VIRT_MULTI_V6:
188 case ILA_ATYPE_NONLOCAL_ADDR:
189 /* These ILA formats are not supported yet. */
190 default:
191 return -EINVAL;
192 }
193
194 if (tb[ILA_ATTR_HOOK_TYPE])
195 hook_type = nla_get_u8(tb[ILA_ATTR_HOOK_TYPE]);
196
197 switch (hook_type) {
198 case ILA_HOOK_ROUTE_OUTPUT:
199 lwt_output = true;
200 break;
201 case ILA_HOOK_ROUTE_INPUT:
202 lwt_output = false;
203 break;
204 default:
205 return -EINVAL;
206 }
207
208 if (tb[ILA_ATTR_CSUM_MODE])
209 csum_mode = nla_get_u8(tb[ILA_ATTR_CSUM_MODE]);
210
211 if (csum_mode == ILA_CSUM_NEUTRAL_MAP &&
212 ila_csum_neutral_set(iaddr->ident)) {
213 /* Don't allow translation if checksum neutral bit is
214 * configured and it's set in the SIR address.
215 */
216 return -EINVAL;
217 }
218
219 newts = lwtunnel_state_alloc(sizeof(*ilwt));
220 if (!newts)
221 return -ENOMEM;
222
223 ilwt = ila_lwt_lwtunnel(newts);
224 ret = dst_cache_init(&ilwt->dst_cache, GFP_ATOMIC);
225 if (ret) {
226 kfree(newts);
227 return ret;
228 }
229
230 ilwt->lwt_output = !!lwt_output;
231
232 p = ila_params_lwtunnel(newts);
233
234 p->csum_mode = csum_mode;
235 p->ident_type = ident_type;
236 p->locator.v64 = (__force __be64)nla_get_u64(tb[ILA_ATTR_LOCATOR]);
237
238 /* Precompute checksum difference for translation since we
239 * know both the old locator and the new one.
240 */
241 p->locator_match = iaddr->loc;
242
243 ila_init_saved_csum(p);
244
245 newts->type = LWTUNNEL_ENCAP_ILA;
246 newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT |
247 LWTUNNEL_STATE_INPUT_REDIRECT;
248
249 if (cfg6->fc_dst_len == 8 * sizeof(struct in6_addr))
250 ilwt->connected = 1;
251
252 *ts = newts;
253
254 return 0;
255 }
256
ila_destroy_state(struct lwtunnel_state * lwt)257 static void ila_destroy_state(struct lwtunnel_state *lwt)
258 {
259 dst_cache_destroy(&ila_lwt_lwtunnel(lwt)->dst_cache);
260 }
261
ila_fill_encap_info(struct sk_buff * skb,struct lwtunnel_state * lwtstate)262 static int ila_fill_encap_info(struct sk_buff *skb,
263 struct lwtunnel_state *lwtstate)
264 {
265 struct ila_params *p = ila_params_lwtunnel(lwtstate);
266 struct ila_lwt *ilwt = ila_lwt_lwtunnel(lwtstate);
267
268 if (nla_put_u64_64bit(skb, ILA_ATTR_LOCATOR, (__force u64)p->locator.v64,
269 ILA_ATTR_PAD))
270 goto nla_put_failure;
271
272 if (nla_put_u8(skb, ILA_ATTR_CSUM_MODE, (__force u8)p->csum_mode))
273 goto nla_put_failure;
274
275 if (nla_put_u8(skb, ILA_ATTR_IDENT_TYPE, (__force u8)p->ident_type))
276 goto nla_put_failure;
277
278 if (nla_put_u8(skb, ILA_ATTR_HOOK_TYPE,
279 ilwt->lwt_output ? ILA_HOOK_ROUTE_OUTPUT :
280 ILA_HOOK_ROUTE_INPUT))
281 goto nla_put_failure;
282
283 return 0;
284
285 nla_put_failure:
286 return -EMSGSIZE;
287 }
288
ila_encap_nlsize(struct lwtunnel_state * lwtstate)289 static int ila_encap_nlsize(struct lwtunnel_state *lwtstate)
290 {
291 return nla_total_size_64bit(sizeof(u64)) + /* ILA_ATTR_LOCATOR */
292 nla_total_size(sizeof(u8)) + /* ILA_ATTR_CSUM_MODE */
293 nla_total_size(sizeof(u8)) + /* ILA_ATTR_IDENT_TYPE */
294 nla_total_size(sizeof(u8)) + /* ILA_ATTR_HOOK_TYPE */
295 0;
296 }
297
ila_encap_cmp(struct lwtunnel_state * a,struct lwtunnel_state * b)298 static int ila_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
299 {
300 struct ila_params *a_p = ila_params_lwtunnel(a);
301 struct ila_params *b_p = ila_params_lwtunnel(b);
302
303 return (a_p->locator.v64 != b_p->locator.v64);
304 }
305
306 static const struct lwtunnel_encap_ops ila_encap_ops = {
307 .build_state = ila_build_state,
308 .destroy_state = ila_destroy_state,
309 .output = ila_output,
310 .input = ila_input,
311 .fill_encap = ila_fill_encap_info,
312 .get_encap_size = ila_encap_nlsize,
313 .cmp_encap = ila_encap_cmp,
314 .owner = THIS_MODULE,
315 };
316
ila_lwt_init(void)317 int ila_lwt_init(void)
318 {
319 return lwtunnel_encap_add_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA);
320 }
321
ila_lwt_fini(void)322 void ila_lwt_fini(void)
323 {
324 lwtunnel_encap_del_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA);
325 }
326