1 /*-
2 * Copyright (c) 2015
3 * Alexander V. Chernikov <melifaro@FreeBSD.org>
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32
33 #include "opt_inet.h"
34 #include "opt_inet6.h"
35 #include "opt_route.h"
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/lock.h>
40 #include <sys/rmlock.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/sysctl.h>
45 #include <sys/kernel.h>
46
47 #include <net/if.h>
48 #include <net/if_var.h>
49 #include <net/if_dl.h>
50 #include <net/route.h>
51 #include <net/route/route_ctl.h>
52 #include <net/route/route_var.h>
53 #include <net/route/fib_algo.h>
54 #include <net/route/nhop.h>
55 #include <net/toeplitz.h>
56 #include <net/vnet.h>
57
58 #include <netinet/in.h>
59 #include <netinet/in_var.h>
60 #include <netinet/ip_mroute.h>
61 #include <netinet/ip6.h>
62 #include <netinet6/in6_fib.h>
63 #include <netinet6/in6_var.h>
64 #include <netinet6/nd6.h>
65 #include <netinet6/scope6_var.h>
66
67 #include <net/if_types.h>
68
69 #ifdef INET6
70
71 CHK_STRUCT_ROUTE_COMPAT(struct route_in6, ro_dst);
72
73 #ifdef FIB_ALGO
74 VNET_DEFINE(struct fib_dp *, inet6_dp);
75 #endif
76
77 #ifdef ROUTE_MPATH
78 struct _hash_5tuple_ipv6 {
79 struct in6_addr src;
80 struct in6_addr dst;
81 unsigned short src_port;
82 unsigned short dst_port;
83 char proto;
84 char spare[3];
85 };
86 _Static_assert(sizeof(struct _hash_5tuple_ipv6) == 40,
87 "_hash_5tuple_ipv6 size is wrong");
88
89 uint32_t
90 fib6_calc_software_hash(const struct in6_addr *src, const struct in6_addr *dst,
91 unsigned short src_port, unsigned short dst_port, char proto,
92 uint32_t *phashtype)
93 {
94 struct _hash_5tuple_ipv6 data;
95
96 data.src = *src;
97 data.dst = *dst;
98 data.src_port = src_port;
99 data.dst_port = dst_port;
100 data.proto = proto;
101 data.spare[0] = data.spare[1] = data.spare[2] = 0;
102
103 *phashtype = M_HASHTYPE_OPAQUE_HASH;
104
105 return (toeplitz_hash(MPATH_ENTROPY_KEY_LEN, mpath_entropy_key,
106 sizeof(data), (uint8_t *)&data));
107 }
108 #endif
109
110 /*
111 * Looks up path in fib @fibnum specified by @dst.
112 * Assumes scope is deembedded and provided in @scopeid.
113 *
114 * Returns path nexthop on success. Nexthop is safe to use
115 * within the current network epoch. If longer lifetime is required,
116 * one needs to pass NHR_REF as a flag. This will return referenced
117 * nexthop.
118 */
119 #ifdef FIB_ALGO
120 struct nhop_object *
121 fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6,
122 uint32_t scopeid, uint32_t flags, uint32_t flowid)
123 {
124 struct nhop_object *nh;
125 struct fib_dp *dp = &V_inet6_dp[fibnum];
126 struct flm_lookup_key key = {.addr6 = dst6 };
127
128 nh = dp->f(dp->arg, key, scopeid);
129 if (nh != NULL) {
130 nh = nhop_select(nh, flowid);
131 /* Ensure route & ifp is UP */
132 if (RT_LINK_IS_UP(nh->nh_ifp)) {
133 if (flags & NHR_REF)
134 nhop_ref_object(nh);
135 return (nh);
136 }
137 }
138 RTSTAT_INC(rts_unreach);
139 return (NULL);
140 }
141 #else
142 struct nhop_object *
143 fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6,
144 uint32_t scopeid, uint32_t flags, uint32_t flowid)
145 {
146 RIB_RLOCK_TRACKER;
147 struct rib_head *rh;
148 struct radix_node *rn;
149 struct nhop_object *nh;
150
151 KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum"));
152 rh = rt_tables_get_rnh(fibnum, AF_INET6);
153 if (rh == NULL)
154 return (NULL);
155
156 struct sockaddr_in6 sin6 = {
157 .sin6_len = sizeof(struct sockaddr_in6),
158 .sin6_addr = *dst6,
159 };
160
161 /* Assume scopeid is valid and embed it directly */
162 if (IN6_IS_SCOPE_LINKLOCAL(dst6))
163 sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
164
165 RIB_RLOCK(rh);
166 rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
167 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
168 nh = nhop_select((RNTORT(rn))->rt_nhop, flowid);
169 /* Ensure route & ifp is UP */
170 if (RT_LINK_IS_UP(nh->nh_ifp)) {
171 if (flags & NHR_REF)
172 nhop_ref_object(nh);
173 RIB_RUNLOCK(rh);
174 return (nh);
175 }
176 }
177 RIB_RUNLOCK(rh);
178
179 RTSTAT_INC(rts_unreach);
180 return (NULL);
181 }
182 #endif
183
184 inline static int
185 check_urpf_nhop(const struct nhop_object *nh, uint32_t flags,
186 const struct ifnet *src_if)
187 {
188
189 if (src_if != NULL && nh->nh_aifp == src_if) {
190 return (1);
191 }
192 if (src_if == NULL) {
193 if ((flags & NHR_NODEFAULT) == 0)
194 return (1);
195 else if ((nh->nh_flags & NHF_DEFAULT) == 0)
196 return (1);
197 }
198
199 return (0);
200 }
201
202 static int
203 check_urpf(struct nhop_object *nh, uint32_t flags,
204 const struct ifnet *src_if)
205 {
206 #ifdef ROUTE_MPATH
207 if (NH_IS_NHGRP(nh)) {
208 struct weightened_nhop *wn;
209 uint32_t num_nhops;
210 wn = nhgrp_get_nhops((struct nhgrp_object *)nh, &num_nhops);
211 for (int i = 0; i < num_nhops; i++) {
212 if (check_urpf_nhop(wn[i].nh, flags, src_if) != 0)
213 return (1);
214 }
215 return (0);
216 } else
217 #endif
218 return (check_urpf_nhop(nh, flags, src_if));
219 }
220
221 #ifndef FIB_ALGO
222 static struct nhop_object *
223 lookup_nhop(uint32_t fibnum, const struct in6_addr *dst6,
224 uint32_t scopeid)
225 {
226 RIB_RLOCK_TRACKER;
227 struct rib_head *rh;
228 struct radix_node *rn;
229 struct nhop_object *nh;
230
231 KASSERT((fibnum < rt_numfibs), ("fib6_check_urpf: bad fibnum"));
232 rh = rt_tables_get_rnh(fibnum, AF_INET6);
233 if (rh == NULL)
234 return (NULL);
235
236 /* Prepare lookup key */
237 struct sockaddr_in6 sin6 = {
238 .sin6_len = sizeof(struct sockaddr_in6),
239 .sin6_addr = *dst6,
240 };
241
242 /* Assume scopeid is valid and embed it directly */
243 if (IN6_IS_SCOPE_LINKLOCAL(dst6))
244 sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
245
246 nh = NULL;
247 RIB_RLOCK(rh);
248 rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
249 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0))
250 nh = RNTORT(rn)->rt_nhop;
251 RIB_RUNLOCK(rh);
252
253 return (nh);
254 }
255 #endif
256
257 /*
258 * Performs reverse path forwarding lookup.
259 * If @src_if is non-zero, verifies that at least 1 path goes via
260 * this interface.
261 * If @src_if is zero, verifies that route exist.
262 * if @flags contains NHR_NOTDEFAULT, do not consider default route.
263 *
264 * Returns 1 if route matching conditions is found, 0 otherwise.
265 */
266 int
267 fib6_check_urpf(uint32_t fibnum, const struct in6_addr *dst6,
268 uint32_t scopeid, uint32_t flags, const struct ifnet *src_if)
269 {
270 struct nhop_object *nh;
271 #ifdef FIB_ALGO
272 struct fib_dp *dp = &V_inet6_dp[fibnum];
273 struct flm_lookup_key key = {.addr6 = dst6 };
274
275 nh = dp->f(dp->arg, key, scopeid);
276 #else
277 nh = lookup_nhop(fibnum, dst6, scopeid);
278 #endif
279 if (nh != NULL)
280 return (check_urpf(nh, flags, src_if));
281 return (0);
282 }
283
284 /*
285 * Function returning prefix match data along with the nexthop data.
286 * Intended to be used by the control plane code.
287 * Supported flags:
288 * NHR_UNLOCKED: do not lock radix during lookup.
289 * Returns pointer to rtentry and raw nexthop in @rnd. Both rtentry
290 * and nexthop are safe to use within current epoch. Note:
291 * Note: rnd_nhop can actually be the nexthop group.
292 */
293 struct rtentry *
294 fib6_lookup_rt(uint32_t fibnum, const struct in6_addr *dst6,
295 uint32_t scopeid, uint32_t flags, struct route_nhop_data *rnd)
296 {
297 RIB_RLOCK_TRACKER;
298 struct rib_head *rh;
299 struct radix_node *rn;
300 struct rtentry *rt;
301
302 KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum"));
303 rh = rt_tables_get_rnh(fibnum, AF_INET6);
304 if (rh == NULL)
305 return (NULL);
306
307 struct sockaddr_in6 sin6 = {
308 .sin6_len = sizeof(struct sockaddr_in6),
309 .sin6_addr = *dst6,
310 };
311
312 /* Assume scopeid is valid and embed it directly */
313 if (IN6_IS_SCOPE_LINKLOCAL(dst6))
314 sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
315
316 rt = NULL;
317 if (!(flags & NHR_UNLOCKED))
318 RIB_RLOCK(rh);
319 rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
320 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
321 rt = (struct rtentry *)rn;
322 rnd->rnd_nhop = rt->rt_nhop;
323 rnd->rnd_weight = rt->rt_weight;
324 }
325 if (!(flags & NHR_UNLOCKED))
326 RIB_RUNLOCK(rh);
327
328 return (rt);
329 }
330
331 struct nhop_object *
332 fib6_lookup_debugnet(uint32_t fibnum, const struct in6_addr *dst6,
333 uint32_t scopeid, uint32_t flags)
334 {
335 struct rtentry *rt;
336 struct route_nhop_data rnd;
337
338 rt = fib6_lookup_rt(fibnum, dst6, scopeid, NHR_UNLOCKED, &rnd);
339 if (rt != NULL) {
340 struct nhop_object *nh = nhop_select(rnd.rnd_nhop, 0);
341 /* Ensure route & ifp is UP */
342 if (RT_LINK_IS_UP(nh->nh_ifp))
343 return (nh);
344 }
345
346 return (NULL);
347 }
348
349 #endif
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