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_route.h"
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/lock.h>
37 #include <sys/rmlock.h>
38 #include <sys/malloc.h>
39 #include <sys/mbuf.h>
40 #include <sys/socket.h>
41 #include <sys/sysctl.h>
42 #include <sys/kernel.h>
43
44 #include <net/if.h>
45 #include <net/if_var.h>
46 #include <net/if_dl.h>
47 #include <net/if_private.h>
48 #include <net/route.h>
49 #include <net/route/route_ctl.h>
50 #include <net/route/route_var.h>
51 #include <net/route/fib_algo.h>
52 #include <net/route/nhop.h>
53 #include <net/toeplitz.h>
54 #include <net/vnet.h>
55
56 #include <netinet/in.h>
57 #include <netinet/in_var.h>
58 #include <netinet/in_fib.h>
59
60 #ifdef INET
61
62 /* Verify struct route compatibility */
63 /* Assert 'struct route_in' is compatible with 'struct route' */
64 CHK_STRUCT_ROUTE_COMPAT(struct route_in, ro_dst4);
65
66 #ifdef FIB_ALGO
67 VNET_DEFINE(struct fib_dp *, inet_dp);
68 #endif
69
70 #ifdef ROUTE_MPATH
71 struct _hash_5tuple_ipv4 {
72 struct in_addr src;
73 struct in_addr dst;
74 unsigned short src_port;
75 unsigned short dst_port;
76 char proto;
77 char spare[3];
78 };
79 _Static_assert(sizeof(struct _hash_5tuple_ipv4) == 16,
80 "_hash_5tuple_ipv4 size is wrong");
81
82 uint32_t
fib4_calc_software_hash(struct in_addr src,struct in_addr dst,unsigned short src_port,unsigned short dst_port,char proto,uint32_t * phashtype)83 fib4_calc_software_hash(struct in_addr src, struct in_addr dst,
84 unsigned short src_port, unsigned short dst_port, char proto,
85 uint32_t *phashtype)
86 {
87 struct _hash_5tuple_ipv4 data;
88
89 data.src = src;
90 data.dst = dst;
91 data.src_port = src_port;
92 data.dst_port = dst_port;
93 data.proto = proto;
94 data.spare[0] = data.spare[1] = data.spare[2] = 0;
95
96 *phashtype = M_HASHTYPE_OPAQUE;
97
98 return (toeplitz_hash(MPATH_ENTROPY_KEY_LEN, mpath_entropy_key,
99 sizeof(data), (uint8_t *)&data));
100 }
101 #endif
102
103 /*
104 * Looks up path in fib @fibnum specified by @dst.
105 * Returns path nexthop on success. Nexthop is safe to use
106 * within the current network epoch. If longer lifetime is required,
107 * one needs to pass NHR_REF as a flag. This will return referenced
108 * nexthop.
109 */
110 #ifdef FIB_ALGO
111 struct nhop_object *
fib4_lookup(uint32_t fibnum,struct in_addr dst,uint32_t scopeid,uint32_t flags,uint32_t flowid)112 fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
113 uint32_t flags, uint32_t flowid)
114 {
115 struct nhop_object *nh;
116 struct fib_dp *dp = &V_inet_dp[fibnum];
117 struct flm_lookup_key key = {.addr4 = dst };
118
119 nh = dp->f(dp->arg, key, scopeid);
120 if (nh != NULL) {
121 nh = nhop_select(nh, flowid);
122 /* Ensure route & ifp is UP */
123 if (RT_LINK_IS_UP(nh->nh_ifp)) {
124 if (flags & NHR_REF)
125 nhop_ref_object(nh);
126 return (nh);
127 }
128 }
129 RTSTAT_INC(rts_unreach);
130 return (NULL);
131 }
132 #else
133 struct nhop_object *
fib4_lookup(uint32_t fibnum,struct in_addr dst,uint32_t scopeid,uint32_t flags,uint32_t flowid)134 fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
135 uint32_t flags, uint32_t flowid)
136 {
137 RIB_RLOCK_TRACKER;
138 struct rib_head *rh;
139 struct radix_node *rn;
140 struct nhop_object *nh;
141
142 KASSERT((fibnum < rt_numfibs), ("fib4_lookup: bad fibnum"));
143 rh = rt_tables_get_rnh(fibnum, AF_INET);
144 if (rh == NULL)
145 return (NULL);
146
147 /* Prepare lookup key */
148 struct sockaddr_in sin4 = {
149 .sin_family = AF_INET,
150 .sin_len = sizeof(struct sockaddr_in),
151 .sin_addr = dst,
152 };
153
154 nh = NULL;
155 RIB_RLOCK(rh);
156 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head);
157 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
158 nh = nhop_select((RNTORT(rn))->rt_nhop, flowid);
159 /* Ensure route & ifp is UP */
160 if (RT_LINK_IS_UP(nh->nh_ifp)) {
161 if (flags & NHR_REF)
162 nhop_ref_object(nh);
163 RIB_RUNLOCK(rh);
164 return (nh);
165 }
166 }
167 RIB_RUNLOCK(rh);
168
169 RTSTAT_INC(rts_unreach);
170 return (NULL);
171 }
172 #endif
173
174 inline static int
check_urpf_nhop(const struct nhop_object * nh,uint32_t flags,const struct ifnet * src_if)175 check_urpf_nhop(const struct nhop_object *nh, uint32_t flags,
176 const struct ifnet *src_if)
177 {
178
179 if (src_if != NULL && nh->nh_aifp == src_if) {
180 return (1);
181 }
182 if (src_if == NULL) {
183 if ((flags & NHR_NODEFAULT) == 0)
184 return (1);
185 else if ((nh->nh_flags & NHF_DEFAULT) == 0)
186 return (1);
187 }
188
189 return (0);
190 }
191
192 static int
check_urpf(struct nhop_object * nh,uint32_t flags,const struct ifnet * src_if)193 check_urpf(struct nhop_object *nh, uint32_t flags,
194 const struct ifnet *src_if)
195 {
196 #ifdef ROUTE_MPATH
197 if (NH_IS_NHGRP(nh)) {
198 const struct weightened_nhop *wn;
199 uint32_t num_nhops;
200 wn = nhgrp_get_nhops((struct nhgrp_object *)nh, &num_nhops);
201 for (int i = 0; i < num_nhops; i++) {
202 if (check_urpf_nhop(wn[i].nh, flags, src_if) != 0)
203 return (1);
204 }
205 return (0);
206 } else
207 #endif
208 return (check_urpf_nhop(nh, flags, src_if));
209 }
210
211 #ifndef FIB_ALGO
212 static struct nhop_object *
lookup_nhop(uint32_t fibnum,struct in_addr dst,uint32_t scopeid)213 lookup_nhop(uint32_t fibnum, struct in_addr dst, uint32_t scopeid)
214 {
215 RIB_RLOCK_TRACKER;
216 struct rib_head *rh;
217 struct radix_node *rn;
218 struct nhop_object *nh;
219
220 KASSERT((fibnum < rt_numfibs), ("fib4_check_urpf: bad fibnum"));
221 rh = rt_tables_get_rnh(fibnum, AF_INET);
222 if (rh == NULL)
223 return (NULL);
224
225 /* Prepare lookup key */
226 struct sockaddr_in sin4;
227 memset(&sin4, 0, sizeof(sin4));
228 sin4.sin_len = sizeof(struct sockaddr_in);
229 sin4.sin_addr = dst;
230
231 nh = NULL;
232 RIB_RLOCK(rh);
233 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head);
234 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0))
235 nh = RNTORT(rn)->rt_nhop;
236 RIB_RUNLOCK(rh);
237
238 return (nh);
239 }
240 #endif
241
242 /*
243 * Performs reverse path forwarding lookup.
244 * If @src_if is non-zero, verifies that at least 1 path goes via
245 * this interface.
246 * If @src_if is zero, verifies that route exist.
247 * if @flags contains NHR_NOTDEFAULT, do not consider default route.
248 *
249 * Returns 1 if route matching conditions is found, 0 otherwise.
250 */
251 int
fib4_check_urpf(uint32_t fibnum,struct in_addr dst,uint32_t scopeid,uint32_t flags,const struct ifnet * src_if)252 fib4_check_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
253 uint32_t flags, const struct ifnet *src_if)
254 {
255 struct nhop_object *nh;
256 #ifdef FIB_ALGO
257 struct fib_dp *dp = &V_inet_dp[fibnum];
258 struct flm_lookup_key key = {.addr4 = dst };
259
260 nh = dp->f(dp->arg, key, scopeid);
261 #else
262 nh = lookup_nhop(fibnum, dst, scopeid);
263 #endif
264 if (nh != NULL)
265 return (check_urpf(nh, flags, src_if));
266
267 return (0);
268 }
269
270 /*
271 * Function returning prefix match data along with the nexthop data.
272 * Intended to be used by the control plane code.
273 * Supported flags:
274 * NHR_UNLOCKED: do not lock radix during lookup.
275 * Returns pointer to rtentry and raw nexthop in @rnd. Both rtentry
276 * and nexthop are safe to use within current epoch. Note:
277 * Note: rnd_nhop can actually be the nexthop group.
278 */
279 struct rtentry *
fib4_lookup_rt(uint32_t fibnum,struct in_addr dst,uint32_t scopeid,uint32_t flags,struct route_nhop_data * rnd)280 fib4_lookup_rt(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
281 uint32_t flags, struct route_nhop_data *rnd)
282 {
283 RIB_RLOCK_TRACKER;
284 struct rib_head *rh;
285 struct radix_node *rn;
286 struct rtentry *rt;
287
288 KASSERT((fibnum < rt_numfibs), ("fib4_lookup_rt: bad fibnum"));
289 rh = rt_tables_get_rnh(fibnum, AF_INET);
290 if (rh == NULL)
291 return (NULL);
292
293 /* Prepare lookup key */
294 struct sockaddr_in sin4 = {
295 .sin_family = AF_INET,
296 .sin_len = sizeof(struct sockaddr_in),
297 .sin_addr = dst,
298 };
299
300 rt = NULL;
301 if (!(flags & NHR_UNLOCKED))
302 RIB_RLOCK(rh);
303 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head);
304 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
305 rt = (struct rtentry *)rn;
306 rnd->rnd_nhop = rt->rt_nhop;
307 rnd->rnd_weight = rt->rt_weight;
308 }
309 if (!(flags & NHR_UNLOCKED))
310 RIB_RUNLOCK(rh);
311
312 return (rt);
313 }
314
315 struct nhop_object *
fib4_lookup_debugnet(uint32_t fibnum,struct in_addr dst,uint32_t scopeid,uint32_t flags)316 fib4_lookup_debugnet(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
317 uint32_t flags)
318 {
319 struct rtentry *rt;
320 struct route_nhop_data rnd;
321
322 rt = fib4_lookup_rt(fibnum, dst, scopeid, NHR_UNLOCKED, &rnd);
323 if (rt != NULL) {
324 struct nhop_object *nh = nhop_select(rnd.rnd_nhop, 0);
325 /* Ensure route & ifp is UP */
326 if (RT_LINK_IS_UP(nh->nh_ifp))
327 return (nh);
328 }
329
330 return (NULL);
331 }
332
333 #endif
334