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 #include "opt_inet.h"
32 #include "opt_inet6.h"
33 #include "opt_route.h"
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/lock.h>
38 #include <sys/rmlock.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/socket.h>
42 #include <sys/sysctl.h>
43 #include <sys/kernel.h>
44
45 #include <net/if.h>
46 #include <net/if_var.h>
47 #include <net/if_dl.h>
48 #include <net/if_private.h>
49 #include <net/route.h>
50 #include <net/route/route_ctl.h>
51 #include <net/route/route_var.h>
52 #include <net/route/fib_algo.h>
53 #include <net/route/nhop.h>
54 #include <net/toeplitz.h>
55 #include <net/vnet.h>
56
57 #include <netinet/in.h>
58 #include <netinet/in_var.h>
59 #include <netinet/ip_mroute.h>
60 #include <netinet/ip6.h>
61 #include <netinet6/in6_fib.h>
62 #include <netinet6/in6_var.h>
63 #include <netinet6/nd6.h>
64 #include <netinet6/scope6_var.h>
65
66 #include <net/if_types.h>
67
68 #ifdef INET6
69
70 CHK_STRUCT_ROUTE_COMPAT(struct route_in6, ro_dst);
71
72 #ifdef FIB_ALGO
73 VNET_DEFINE(struct fib_dp *, inet6_dp);
74 #endif
75
76 #ifdef ROUTE_MPATH
77 struct _hash_5tuple_ipv6 {
78 struct in6_addr src;
79 struct in6_addr dst;
80 unsigned short src_port;
81 unsigned short dst_port;
82 char proto;
83 char spare[3];
84 };
85 _Static_assert(sizeof(struct _hash_5tuple_ipv6) == 40,
86 "_hash_5tuple_ipv6 size is wrong");
87
88 uint32_t
fib6_calc_software_hash(const struct in6_addr * src,const struct in6_addr * dst,unsigned short src_port,unsigned short dst_port,char proto,uint32_t * phashtype)89 fib6_calc_software_hash(const struct in6_addr *src, const struct in6_addr *dst,
90 unsigned short src_port, unsigned short dst_port, char proto,
91 uint32_t *phashtype)
92 {
93 struct _hash_5tuple_ipv6 data;
94
95 data.src = *src;
96 data.dst = *dst;
97 data.src_port = src_port;
98 data.dst_port = dst_port;
99 data.proto = proto;
100 data.spare[0] = data.spare[1] = data.spare[2] = 0;
101
102 *phashtype = M_HASHTYPE_OPAQUE_HASH;
103
104 return (toeplitz_hash(MPATH_ENTROPY_KEY_LEN, mpath_entropy_key,
105 sizeof(data), (uint8_t *)&data));
106 }
107 #endif
108
109 /*
110 * Looks up path in fib @fibnum specified by @dst.
111 * Assumes scope is deembedded and provided in @scopeid.
112 *
113 * Returns path nexthop on success. Nexthop is safe to use
114 * within the current network epoch. If longer lifetime is required,
115 * one needs to pass NHR_REF as a flag. This will return referenced
116 * nexthop.
117 */
118 #ifdef FIB_ALGO
119 struct nhop_object *
fib6_lookup(uint32_t fibnum,const struct in6_addr * dst6,uint32_t scopeid,uint32_t flags,uint32_t flowid)120 fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6,
121 uint32_t scopeid, uint32_t flags, uint32_t flowid)
122 {
123 struct nhop_object *nh;
124 struct fib_dp *dp = &V_inet6_dp[fibnum];
125 struct flm_lookup_key key = {.addr6 = dst6 };
126
127 nh = dp->f(dp->arg, key, scopeid);
128 if (nh != NULL) {
129 nh = nhop_select(nh, flowid);
130 /* Ensure route & ifp is UP */
131 if (RT_LINK_IS_UP(nh->nh_ifp)) {
132 if (flags & NHR_REF)
133 nhop_ref_object(nh);
134 return (nh);
135 }
136 }
137 RTSTAT_INC(rts_unreach);
138 return (NULL);
139 }
140 #else
141 struct nhop_object *
fib6_lookup(uint32_t fibnum,const struct in6_addr * dst6,uint32_t scopeid,uint32_t flags,uint32_t flowid)142 fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6,
143 uint32_t scopeid, uint32_t flags, uint32_t flowid)
144 {
145 RIB_RLOCK_TRACKER;
146 struct rib_head *rh;
147 struct radix_node *rn;
148 struct nhop_object *nh;
149
150 KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum"));
151 rh = rt_tables_get_rnh(fibnum, AF_INET6);
152 if (rh == NULL)
153 return (NULL);
154
155 struct sockaddr_in6 sin6 = {
156 .sin6_len = sizeof(struct sockaddr_in6),
157 .sin6_addr = *dst6,
158 };
159
160 /* Assume scopeid is valid and embed it directly */
161 if (IN6_IS_SCOPE_LINKLOCAL(dst6))
162 sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
163
164 RIB_RLOCK(rh);
165 rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
166 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
167 nh = nhop_select((RNTORT(rn))->rt_nhop, flowid);
168 /* Ensure route & ifp is UP */
169 if (RT_LINK_IS_UP(nh->nh_ifp)) {
170 if (flags & NHR_REF)
171 nhop_ref_object(nh);
172 RIB_RUNLOCK(rh);
173 return (nh);
174 }
175 }
176 RIB_RUNLOCK(rh);
177
178 RTSTAT_INC(rts_unreach);
179 return (NULL);
180 }
181 #endif
182
183 inline static int
check_urpf_nhop(const struct nhop_object * nh,uint32_t flags,const struct ifnet * src_if)184 check_urpf_nhop(const struct nhop_object *nh, uint32_t flags,
185 const struct ifnet *src_if)
186 {
187
188 if (src_if != NULL && nh->nh_aifp == src_if) {
189 return (1);
190 }
191 if (src_if == NULL) {
192 if ((flags & NHR_NODEFAULT) == 0)
193 return (1);
194 else if ((nh->nh_flags & NHF_DEFAULT) == 0)
195 return (1);
196 }
197
198 return (0);
199 }
200
201 static int
check_urpf(struct nhop_object * nh,uint32_t flags,const struct ifnet * src_if)202 check_urpf(struct nhop_object *nh, uint32_t flags,
203 const struct ifnet *src_if)
204 {
205 #ifdef ROUTE_MPATH
206 if (NH_IS_NHGRP(nh)) {
207 const struct weightened_nhop *wn;
208 uint32_t num_nhops;
209 wn = nhgrp_get_nhops((struct nhgrp_object *)nh, &num_nhops);
210 for (int i = 0; i < num_nhops; i++) {
211 if (check_urpf_nhop(wn[i].nh, flags, src_if) != 0)
212 return (1);
213 }
214 return (0);
215 } else
216 #endif
217 return (check_urpf_nhop(nh, flags, src_if));
218 }
219
220 #ifndef FIB_ALGO
221 static struct nhop_object *
lookup_nhop(uint32_t fibnum,const struct in6_addr * dst6,uint32_t scopeid)222 lookup_nhop(uint32_t fibnum, const struct in6_addr *dst6,
223 uint32_t scopeid)
224 {
225 RIB_RLOCK_TRACKER;
226 struct rib_head *rh;
227 struct radix_node *rn;
228 struct nhop_object *nh;
229
230 KASSERT((fibnum < rt_numfibs), ("fib6_check_urpf: bad fibnum"));
231 rh = rt_tables_get_rnh(fibnum, AF_INET6);
232 if (rh == NULL)
233 return (NULL);
234
235 /* Prepare lookup key */
236 struct sockaddr_in6 sin6 = {
237 .sin6_len = sizeof(struct sockaddr_in6),
238 .sin6_addr = *dst6,
239 };
240
241 /* Assume scopeid is valid and embed it directly */
242 if (IN6_IS_SCOPE_LINKLOCAL(dst6))
243 sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
244
245 nh = NULL;
246 RIB_RLOCK(rh);
247 rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
248 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0))
249 nh = RNTORT(rn)->rt_nhop;
250 RIB_RUNLOCK(rh);
251
252 return (nh);
253 }
254 #endif
255
256 /*
257 * Performs reverse path forwarding lookup.
258 * If @src_if is non-zero, verifies that at least 1 path goes via
259 * this interface.
260 * If @src_if is zero, verifies that route exist.
261 * if @flags contains NHR_NOTDEFAULT, do not consider default route.
262 *
263 * Returns 1 if route matching conditions is found, 0 otherwise.
264 */
265 int
fib6_check_urpf(uint32_t fibnum,const struct in6_addr * dst6,uint32_t scopeid,uint32_t flags,const struct ifnet * src_if)266 fib6_check_urpf(uint32_t fibnum, const struct in6_addr *dst6,
267 uint32_t scopeid, uint32_t flags, const struct ifnet *src_if)
268 {
269 struct nhop_object *nh;
270 #ifdef FIB_ALGO
271 struct fib_dp *dp = &V_inet6_dp[fibnum];
272 struct flm_lookup_key key = {.addr6 = dst6 };
273
274 nh = dp->f(dp->arg, key, scopeid);
275 #else
276 nh = lookup_nhop(fibnum, dst6, scopeid);
277 #endif
278 if (nh != NULL)
279 return (check_urpf(nh, flags, src_if));
280 return (0);
281 }
282
283 /*
284 * Function returning prefix match data along with the nexthop data.
285 * Intended to be used by the control plane code.
286 * Supported flags:
287 * NHR_UNLOCKED: do not lock radix during lookup.
288 * Returns pointer to rtentry and raw nexthop in @rnd. Both rtentry
289 * and nexthop are safe to use within current epoch. Note:
290 * Note: rnd_nhop can actually be the nexthop group.
291 */
292 struct rtentry *
fib6_lookup_rt(uint32_t fibnum,const struct in6_addr * dst6,uint32_t scopeid,uint32_t flags,struct route_nhop_data * rnd)293 fib6_lookup_rt(uint32_t fibnum, const struct in6_addr *dst6,
294 uint32_t scopeid, uint32_t flags, struct route_nhop_data *rnd)
295 {
296 RIB_RLOCK_TRACKER;
297 struct rib_head *rh;
298 struct radix_node *rn;
299 struct rtentry *rt;
300
301 KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum"));
302 rh = rt_tables_get_rnh(fibnum, AF_INET6);
303 if (rh == NULL)
304 return (NULL);
305
306 struct sockaddr_in6 sin6 = {
307 .sin6_len = sizeof(struct sockaddr_in6),
308 .sin6_addr = *dst6,
309 };
310
311 /* Assume scopeid is valid and embed it directly */
312 if (IN6_IS_SCOPE_LINKLOCAL(dst6))
313 sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
314
315 rt = NULL;
316 if (!(flags & NHR_UNLOCKED))
317 RIB_RLOCK(rh);
318 rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
319 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
320 rt = (struct rtentry *)rn;
321 rnd->rnd_nhop = rt->rt_nhop;
322 rnd->rnd_weight = rt->rt_weight;
323 }
324 if (!(flags & NHR_UNLOCKED))
325 RIB_RUNLOCK(rh);
326
327 return (rt);
328 }
329
330 struct nhop_object *
fib6_lookup_debugnet(uint32_t fibnum,const struct in6_addr * dst6,uint32_t scopeid,uint32_t flags)331 fib6_lookup_debugnet(uint32_t fibnum, const struct in6_addr *dst6,
332 uint32_t scopeid, uint32_t flags)
333 {
334 struct rtentry *rt;
335 struct route_nhop_data rnd;
336
337 rt = fib6_lookup_rt(fibnum, dst6, scopeid, NHR_UNLOCKED, &rnd);
338 if (rt != NULL) {
339 struct nhop_object *nh = nhop_select(rnd.rnd_nhop, 0);
340 /* Ensure route & ifp is UP */
341 if (RT_LINK_IS_UP(nh->nh_ifp))
342 return (nh);
343 }
344
345 return (NULL);
346 }
347
348 #endif
349