xref: /freebsd/sys/netinet6/in6_fib.c (revision 3c67996ca9a6231d5f737a32efe618b2ead7acc1)
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 #include "opt_mpath.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/lock.h>
41 #include <sys/rmlock.h>
42 #include <sys/malloc.h>
43 #include <sys/mbuf.h>
44 #include <sys/socket.h>
45 #include <sys/sysctl.h>
46 #include <sys/kernel.h>
47 
48 #include <net/if.h>
49 #include <net/if_var.h>
50 #include <net/if_dl.h>
51 #include <net/route.h>
52 #include <net/route/route_var.h>
53 #include <net/route/nhop.h>
54 #include <net/route/shared.h>
55 #include <net/vnet.h>
56 
57 #ifdef RADIX_MPATH
58 #include <net/radix_mpath.h>
59 #endif
60 
61 #include <netinet/in.h>
62 #include <netinet/in_var.h>
63 #include <netinet/ip_mroute.h>
64 #include <netinet/ip6.h>
65 #include <netinet6/in6_fib.h>
66 #include <netinet6/in6_var.h>
67 #include <netinet6/nd6.h>
68 #include <netinet6/scope6_var.h>
69 
70 #include <net/if_types.h>
71 
72 #ifdef INET6
73 
74 CHK_STRUCT_ROUTE_COMPAT(struct route_in6, ro_dst);
75 
76 /*
77  * Looks up path in fib @fibnum specified by @dst.
78  * Assumes scope is deembedded and provided in @scopeid.
79  *
80  * Returns path nexthop on success. Nexthop is safe to use
81  *  within the current network epoch. If longer lifetime is required,
82  *  one needs to pass NHR_REF as a flag. This will return referenced
83  *  nexthop.
84  */
85 struct nhop_object *
86 fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6,
87     uint32_t scopeid, uint32_t flags, uint32_t flowid)
88 {
89 	RIB_RLOCK_TRACKER;
90 	struct rib_head *rh;
91 	struct radix_node *rn;
92 	struct rtentry *rt;
93 	struct nhop_object *nh;
94 	struct sockaddr_in6 sin6;
95 
96 	KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum"));
97 	rh = rt_tables_get_rnh(fibnum, AF_INET6);
98 	if (rh == NULL)
99 		return (NULL);
100 
101 	/* TODO: radix changes */
102 	//addr = *dst6;
103 	/* Prepare lookup key */
104 	memset(&sin6, 0, sizeof(sin6));
105 	sin6.sin6_len = sizeof(struct sockaddr_in6);
106 	sin6.sin6_addr = *dst6;
107 
108 	/* Assume scopeid is valid and embed it directly */
109 	if (IN6_IS_SCOPE_LINKLOCAL(dst6))
110 		sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
111 
112 	RIB_RLOCK(rh);
113 	rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
114 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
115 		rt = RNTORT(rn);
116 #ifdef RADIX_MPATH
117 		if (rt_mpath_next(rt) != NULL)
118 			rt = rt_mpath_selectrte(rt, flowid);
119 #endif
120 		nh = rt->rt_nhop;
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 			RIB_RUNLOCK(rh);
126 			return (nh);
127 		}
128 	}
129 	RIB_RUNLOCK(rh);
130 
131 	RTSTAT_INC(rts_unreach);
132 	return (NULL);
133 }
134 
135 inline static int
136 check_urpf(const struct nhop_object *nh, uint32_t flags,
137     const struct ifnet *src_if)
138 {
139 
140 	if (src_if != NULL && nh->nh_aifp == src_if) {
141 		return (1);
142 	}
143 	if (src_if == NULL) {
144 		if ((flags & NHR_NODEFAULT) == 0)
145 			return (1);
146 		else if ((nh->nh_flags & NHF_DEFAULT) == 0)
147 			return (1);
148 	}
149 
150 	return (0);
151 }
152 
153 #ifdef RADIX_MPATH
154 inline static int
155 check_urpf_mpath(struct rtentry *rt, uint32_t flags,
156     const struct ifnet *src_if)
157 {
158 
159 	while (rt != NULL) {
160 		if (check_urpf(rt->rt_nhop, flags, src_if) != 0)
161 			return (1);
162 		rt = rt_mpath_next(rt);
163 	}
164 
165 	return (0);
166 }
167 #endif
168 
169 /*
170  * Performs reverse path forwarding lookup.
171  * If @src_if is non-zero, verifies that at least 1 path goes via
172  *   this interface.
173  * If @src_if is zero, verifies that route exist.
174  * if @flags contains NHR_NOTDEFAULT, do not consider default route.
175  *
176  * Returns 1 if route matching conditions is found, 0 otherwise.
177  */
178 int
179 fib6_check_urpf(uint32_t fibnum, const struct in6_addr *dst6,
180     uint32_t scopeid, uint32_t flags, const struct ifnet *src_if)
181 {
182 	RIB_RLOCK_TRACKER;
183 	struct rib_head *rh;
184 	struct radix_node *rn;
185 	struct rtentry *rt;
186 	struct sockaddr_in6 sin6;
187 	int ret;
188 
189 	KASSERT((fibnum < rt_numfibs), ("fib6_check_urpf: bad fibnum"));
190 	rh = rt_tables_get_rnh(fibnum, AF_INET6);
191 	if (rh == NULL)
192 		return (0);
193 
194 	/* TODO: radix changes */
195 	/* Prepare lookup key */
196 	memset(&sin6, 0, sizeof(sin6));
197 	sin6.sin6_len = sizeof(struct sockaddr_in6);
198 	sin6.sin6_addr = *dst6;
199 
200 	/* Assume scopeid is valid and embed it directly */
201 	if (IN6_IS_SCOPE_LINKLOCAL(dst6))
202 		sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
203 
204 	RIB_RLOCK(rh);
205 	rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
206 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
207 		rt = RNTORT(rn);
208 #ifdef	RADIX_MPATH
209 		ret = check_urpf_mpath(rt, flags, src_if);
210 #else
211 		ret = check_urpf(rt->rt_nhop, flags, src_if);
212 #endif
213 		RIB_RUNLOCK(rh);
214 		return (ret);
215 	}
216 	RIB_RUNLOCK(rh);
217 
218 	return (0);
219 }
220 
221 struct nhop_object *
222 fib6_lookup_debugnet(uint32_t fibnum, const struct in6_addr *dst6,
223     uint32_t scopeid, uint32_t flags)
224 {
225 	struct rib_head *rh;
226 	struct radix_node *rn;
227 	struct rtentry *rt;
228 	struct nhop_object *nh;
229 	struct sockaddr_in6 sin6;
230 
231 	KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum"));
232 	rh = rt_tables_get_rnh(fibnum, AF_INET6);
233 	if (rh == NULL)
234 		return (NULL);
235 
236 	/* TODO: radix changes */
237 	//addr = *dst6;
238 	/* Prepare lookup key */
239 	memset(&sin6, 0, sizeof(sin6));
240 	sin6.sin6_len = sizeof(struct sockaddr_in6);
241 	sin6.sin6_addr = *dst6;
242 
243 	/* Assume scopeid is valid and embed it directly */
244 	if (IN6_IS_SCOPE_LINKLOCAL(dst6))
245 		sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
246 
247 	rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
248 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
249 		rt = RNTORT(rn);
250 		nh = rt->rt_nhop;
251 		/* Ensure route & ifp is UP */
252 		if (RT_LINK_IS_UP(nh->nh_ifp)) {
253 			if (flags & NHR_REF)
254 				nhop_ref_object(nh);
255 			return (nh);
256 		}
257 	}
258 
259 	return (NULL);
260 }
261 
262 #endif
263 
264