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 "opt_inet.h"
31 #include "opt_route.h"
32
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/lock.h>
36 #include <sys/rmlock.h>
37 #include <sys/malloc.h>
38 #include <sys/mbuf.h>
39 #include <sys/socket.h>
40 #include <sys/sysctl.h>
41 #include <sys/kernel.h>
42
43 #include <net/if.h>
44 #include <net/if_var.h>
45 #include <net/if_dl.h>
46 #include <net/if_private.h>
47 #include <net/route.h>
48 #include <net/route/route_ctl.h>
49 #include <net/route/route_var.h>
50 #include <net/route/fib_algo.h>
51 #include <net/route/nhop.h>
52 #include <net/toeplitz.h>
53 #include <net/vnet.h>
54
55 #include <netinet/in.h>
56 #include <netinet/in_var.h>
57 #include <netinet/in_fib.h>
58
59 #ifdef INET
60
61 /* Verify struct route compatibility */
62 /* Assert 'struct route_in' is compatible with 'struct route' */
63 CHK_STRUCT_ROUTE_COMPAT(struct route_in, ro_dst4);
64
65 #ifdef FIB_ALGO
66 VNET_DEFINE(struct fib_dp *, inet_dp);
67 #endif
68
69 #ifdef ROUTE_MPATH
70 struct _hash_5tuple_ipv4 {
71 struct in_addr src;
72 struct in_addr dst;
73 unsigned short src_port;
74 unsigned short dst_port;
75 char proto;
76 char spare[3];
77 };
78 _Static_assert(sizeof(struct _hash_5tuple_ipv4) == 16,
79 "_hash_5tuple_ipv4 size is wrong");
80
81 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)82 fib4_calc_software_hash(struct in_addr src, struct in_addr dst,
83 unsigned short src_port, unsigned short dst_port, char proto,
84 uint32_t *phashtype)
85 {
86 struct _hash_5tuple_ipv4 data;
87
88 data.src = src;
89 data.dst = dst;
90 data.src_port = src_port;
91 data.dst_port = dst_port;
92 data.proto = proto;
93 data.spare[0] = data.spare[1] = data.spare[2] = 0;
94
95 *phashtype = M_HASHTYPE_OPAQUE;
96
97 return (toeplitz_hash(MPATH_ENTROPY_KEY_LEN, mpath_entropy_key,
98 sizeof(data), (uint8_t *)&data));
99 }
100 #endif
101
102 /*
103 * Looks up path in fib @fibnum specified by @dst.
104 * Returns path nexthop on success. Nexthop is safe to use
105 * within the current network epoch. If longer lifetime is required,
106 * one needs to pass NHR_REF as a flag. This will return referenced
107 * nexthop.
108 */
109 #ifdef FIB_ALGO
110 struct nhop_object *
fib4_lookup(uint32_t fibnum,struct in_addr dst,uint32_t scopeid,uint32_t flags,uint32_t flowid)111 fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
112 uint32_t flags, uint32_t flowid)
113 {
114 struct nhop_object *nh;
115 struct fib_dp *dp = &V_inet_dp[fibnum];
116 struct flm_lookup_key key = {.addr4 = dst };
117
118 nh = dp->f(dp->arg, key, scopeid);
119 if (nh != NULL) {
120 nh = nhop_select(nh, flowid);
121 /* Ensure route & ifp is UP */
122 if (RT_LINK_IS_UP(nh->nh_ifp)) {
123 if (flags & NHR_REF)
124 nhop_ref_object(nh);
125 return (nh);
126 }
127 }
128 RTSTAT_INC(rts_unreach);
129 return (NULL);
130 }
131 #else
132 struct nhop_object *
fib4_lookup(uint32_t fibnum,struct in_addr dst,uint32_t scopeid,uint32_t flags,uint32_t flowid)133 fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
134 uint32_t flags, uint32_t flowid)
135 {
136 RIB_RLOCK_TRACKER;
137 struct rib_head *rh;
138 struct radix_node *rn;
139 struct nhop_object *nh;
140
141 KASSERT((fibnum < rt_numfibs), ("fib4_lookup: bad fibnum"));
142 rh = rt_tables_get_rnh(fibnum, AF_INET);
143 if (rh == NULL)
144 return (NULL);
145
146 /* Prepare lookup key */
147 struct sockaddr_in sin4 = {
148 .sin_family = AF_INET,
149 .sin_len = sizeof(struct sockaddr_in),
150 .sin_addr = dst,
151 };
152
153 nh = NULL;
154 RIB_RLOCK(rh);
155 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head);
156 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
157 nh = nhop_select((RNTORT(rn))->rt_nhop, flowid);
158 /* Ensure route & ifp is UP */
159 if (RT_LINK_IS_UP(nh->nh_ifp)) {
160 if (flags & NHR_REF)
161 nhop_ref_object(nh);
162 RIB_RUNLOCK(rh);
163 return (nh);
164 }
165 }
166 RIB_RUNLOCK(rh);
167
168 RTSTAT_INC(rts_unreach);
169 return (NULL);
170 }
171 #endif
172
173 inline static int
check_urpf_nhop(const struct nhop_object * nh,uint32_t flags,const struct ifnet * src_if)174 check_urpf_nhop(const struct nhop_object *nh, uint32_t flags,
175 const struct ifnet *src_if)
176 {
177
178 if (src_if != NULL && nh->nh_aifp == src_if) {
179 return (1);
180 }
181 if (src_if == NULL) {
182 if ((flags & NHR_NODEFAULT) == 0)
183 return (1);
184 else if ((nh->nh_flags & NHF_DEFAULT) == 0)
185 return (1);
186 }
187
188 return (0);
189 }
190
191 static int
check_urpf(struct nhop_object * nh,uint32_t flags,const struct ifnet * src_if)192 check_urpf(struct nhop_object *nh, uint32_t flags,
193 const struct ifnet *src_if)
194 {
195 #ifdef ROUTE_MPATH
196 if (NH_IS_NHGRP(nh)) {
197 const struct weightened_nhop *wn;
198 uint32_t num_nhops;
199 wn = nhgrp_get_nhops((struct nhgrp_object *)nh, &num_nhops);
200 for (int i = 0; i < num_nhops; i++) {
201 if (check_urpf_nhop(wn[i].nh, flags, src_if) != 0)
202 return (1);
203 }
204 return (0);
205 } else
206 #endif
207 return (check_urpf_nhop(nh, flags, src_if));
208 }
209
210 #ifndef FIB_ALGO
211 static struct nhop_object *
lookup_nhop(uint32_t fibnum,struct in_addr dst,uint32_t scopeid)212 lookup_nhop(uint32_t fibnum, struct in_addr dst, uint32_t scopeid)
213 {
214 RIB_RLOCK_TRACKER;
215 struct rib_head *rh;
216 struct radix_node *rn;
217 struct nhop_object *nh;
218
219 KASSERT((fibnum < rt_numfibs), ("fib4_check_urpf: bad fibnum"));
220 rh = rt_tables_get_rnh(fibnum, AF_INET);
221 if (rh == NULL)
222 return (NULL);
223
224 /* Prepare lookup key */
225 struct sockaddr_in sin4;
226 memset(&sin4, 0, sizeof(sin4));
227 sin4.sin_len = sizeof(struct sockaddr_in);
228 sin4.sin_addr = dst;
229
230 nh = NULL;
231 RIB_RLOCK(rh);
232 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head);
233 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0))
234 nh = RNTORT(rn)->rt_nhop;
235 RIB_RUNLOCK(rh);
236
237 return (nh);
238 }
239 #endif
240
241 /*
242 * Performs reverse path forwarding lookup.
243 * If @src_if is non-zero, verifies that at least 1 path goes via
244 * this interface.
245 * If @src_if is zero, verifies that route exist.
246 * if @flags contains NHR_NOTDEFAULT, do not consider default route.
247 *
248 * Returns 1 if route matching conditions is found, 0 otherwise.
249 */
250 int
fib4_check_urpf(uint32_t fibnum,struct in_addr dst,uint32_t scopeid,uint32_t flags,const struct ifnet * src_if)251 fib4_check_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
252 uint32_t flags, const struct ifnet *src_if)
253 {
254 struct nhop_object *nh;
255 #ifdef FIB_ALGO
256 struct fib_dp *dp = &V_inet_dp[fibnum];
257 struct flm_lookup_key key = {.addr4 = dst };
258
259 nh = dp->f(dp->arg, key, scopeid);
260 #else
261 nh = lookup_nhop(fibnum, dst, scopeid);
262 #endif
263 if (nh != NULL)
264 return (check_urpf(nh, flags, src_if));
265
266 return (0);
267 }
268
269 /*
270 * Function returning prefix match data along with the nexthop data.
271 * Intended to be used by the control plane code.
272 * Supported flags:
273 * NHR_UNLOCKED: do not lock radix during lookup.
274 * Returns pointer to rtentry and raw nexthop in @rnd. Both rtentry
275 * and nexthop are safe to use within current epoch. Note:
276 * Note: rnd_nhop can actually be the nexthop group.
277 */
278 struct rtentry *
fib4_lookup_rt(uint32_t fibnum,struct in_addr dst,uint32_t scopeid,uint32_t flags,struct route_nhop_data * rnd)279 fib4_lookup_rt(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
280 uint32_t flags, struct route_nhop_data *rnd)
281 {
282 RIB_RLOCK_TRACKER;
283 struct rib_head *rh;
284 struct radix_node *rn;
285 struct rtentry *rt;
286
287 KASSERT((fibnum < rt_numfibs), ("fib4_lookup_rt: bad fibnum"));
288 rh = rt_tables_get_rnh(fibnum, AF_INET);
289 if (rh == NULL)
290 return (NULL);
291
292 /* Prepare lookup key */
293 struct sockaddr_in sin4 = {
294 .sin_family = AF_INET,
295 .sin_len = sizeof(struct sockaddr_in),
296 .sin_addr = dst,
297 };
298
299 rt = NULL;
300 if (!(flags & NHR_UNLOCKED))
301 RIB_RLOCK(rh);
302 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head);
303 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
304 rt = (struct rtentry *)rn;
305 rnd->rnd_nhop = rt->rt_nhop;
306 rnd->rnd_weight = rt->rt_weight;
307 }
308 if (!(flags & NHR_UNLOCKED))
309 RIB_RUNLOCK(rh);
310
311 return (rt);
312 }
313
314 struct nhop_object *
fib4_lookup_debugnet(uint32_t fibnum,struct in_addr dst,uint32_t scopeid,uint32_t flags)315 fib4_lookup_debugnet(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
316 uint32_t flags)
317 {
318 struct rtentry *rt;
319 struct route_nhop_data rnd;
320
321 rt = fib4_lookup_rt(fibnum, dst, scopeid, NHR_UNLOCKED, &rnd);
322 if (rt != NULL) {
323 struct nhop_object *nh = nhop_select(rnd.rnd_nhop, 0);
324 /* Ensure route & ifp is UP */
325 if (RT_LINK_IS_UP(nh->nh_ifp))
326 return (nh);
327 }
328
329 return (NULL);
330 }
331
332 #endif
333