xref: /freebsd/sys/netinet6/in6_fib.c (revision 6132212808e8dccedc9e5d85fea4390c2f38059a)
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/vnet.h>
55 
56 #ifdef RADIX_MPATH
57 #include <net/radix_mpath.h>
58 #endif
59 
60 #include <netinet/in.h>
61 #include <netinet/in_var.h>
62 #include <netinet/ip_mroute.h>
63 #include <netinet/ip6.h>
64 #include <netinet6/in6_fib.h>
65 #include <netinet6/in6_var.h>
66 #include <netinet6/nd6.h>
67 #include <netinet6/scope6_var.h>
68 
69 #include <net/if_types.h>
70 
71 #ifdef INET6
72 
73 CHK_STRUCT_ROUTE_COMPAT(struct route_in6, ro_dst);
74 
75 /*
76  * Looks up path in fib @fibnum specified by @dst.
77  * Assumes scope is deembedded and provided in @scopeid.
78  *
79  * Returns path nexthop on success. Nexthop is safe to use
80  *  within the current network epoch. If longer lifetime is required,
81  *  one needs to pass NHR_REF as a flag. This will return referenced
82  *  nexthop.
83  */
84 struct nhop_object *
85 fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6,
86     uint32_t scopeid, uint32_t flags, uint32_t flowid)
87 {
88 	RIB_RLOCK_TRACKER;
89 	struct rib_head *rh;
90 	struct radix_node *rn;
91 	struct rtentry *rt;
92 	struct nhop_object *nh;
93 	struct sockaddr_in6 sin6;
94 
95 	KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum"));
96 	rh = rt_tables_get_rnh(fibnum, AF_INET6);
97 	if (rh == NULL)
98 		return (NULL);
99 
100 	/* TODO: radix changes */
101 	//addr = *dst6;
102 	/* Prepare lookup key */
103 	memset(&sin6, 0, sizeof(sin6));
104 	sin6.sin6_len = sizeof(struct sockaddr_in6);
105 	sin6.sin6_addr = *dst6;
106 
107 	/* Assume scopeid is valid and embed it directly */
108 	if (IN6_IS_SCOPE_LINKLOCAL(dst6))
109 		sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
110 
111 	RIB_RLOCK(rh);
112 	rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
113 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
114 		rt = RNTORT(rn);
115 #ifdef RADIX_MPATH
116 		if (rt_mpath_next(rt) != NULL)
117 			rt = rt_mpath_selectrte(rt, flowid);
118 #endif
119 		nh = rt->rt_nhop;
120 		/* Ensure route & ifp is UP */
121 		if (RT_LINK_IS_UP(nh->nh_ifp)) {
122 			if (flags & NHR_REF)
123 				nhop_ref_object(nh);
124 			RIB_RUNLOCK(rh);
125 			return (nh);
126 		}
127 	}
128 	RIB_RUNLOCK(rh);
129 
130 	RTSTAT_INC(rts_unreach);
131 	return (NULL);
132 }
133 
134 inline static int
135 check_urpf(const struct nhop_object *nh, uint32_t flags,
136     const struct ifnet *src_if)
137 {
138 
139 	if (src_if != NULL && nh->nh_aifp == src_if) {
140 		return (1);
141 	}
142 	if (src_if == NULL) {
143 		if ((flags & NHR_NODEFAULT) == 0)
144 			return (1);
145 		else if ((nh->nh_flags & NHF_DEFAULT) == 0)
146 			return (1);
147 	}
148 
149 	return (0);
150 }
151 
152 #ifdef RADIX_MPATH
153 inline static int
154 check_urpf_mpath(struct rtentry *rt, uint32_t flags,
155     const struct ifnet *src_if)
156 {
157 
158 	while (rt != NULL) {
159 		if (check_urpf(rt->rt_nhop, flags, src_if) != 0)
160 			return (1);
161 		rt = rt_mpath_next(rt);
162 	}
163 
164 	return (0);
165 }
166 #endif
167 
168 /*
169  * Performs reverse path forwarding lookup.
170  * If @src_if is non-zero, verifies that at least 1 path goes via
171  *   this interface.
172  * If @src_if is zero, verifies that route exist.
173  * if @flags contains NHR_NOTDEFAULT, do not consider default route.
174  *
175  * Returns 1 if route matching conditions is found, 0 otherwise.
176  */
177 int
178 fib6_check_urpf(uint32_t fibnum, const struct in6_addr *dst6,
179     uint32_t scopeid, uint32_t flags, const struct ifnet *src_if)
180 {
181 	RIB_RLOCK_TRACKER;
182 	struct rib_head *rh;
183 	struct radix_node *rn;
184 	struct rtentry *rt;
185 	struct sockaddr_in6 sin6;
186 	int ret;
187 
188 	KASSERT((fibnum < rt_numfibs), ("fib6_check_urpf: bad fibnum"));
189 	rh = rt_tables_get_rnh(fibnum, AF_INET6);
190 	if (rh == NULL)
191 		return (0);
192 
193 	/* TODO: radix changes */
194 	/* Prepare lookup key */
195 	memset(&sin6, 0, sizeof(sin6));
196 	sin6.sin6_len = sizeof(struct sockaddr_in6);
197 	sin6.sin6_addr = *dst6;
198 
199 	/* Assume scopeid is valid and embed it directly */
200 	if (IN6_IS_SCOPE_LINKLOCAL(dst6))
201 		sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
202 
203 	RIB_RLOCK(rh);
204 	rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
205 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
206 		rt = RNTORT(rn);
207 #ifdef	RADIX_MPATH
208 		ret = check_urpf_mpath(rt, flags, src_if);
209 #else
210 		ret = check_urpf(rt->rt_nhop, flags, src_if);
211 #endif
212 		RIB_RUNLOCK(rh);
213 		return (ret);
214 	}
215 	RIB_RUNLOCK(rh);
216 
217 	return (0);
218 }
219 
220 struct nhop_object *
221 fib6_lookup_debugnet(uint32_t fibnum, const struct in6_addr *dst6,
222     uint32_t scopeid, uint32_t flags)
223 {
224 	struct rib_head *rh;
225 	struct radix_node *rn;
226 	struct rtentry *rt;
227 	struct nhop_object *nh;
228 	struct sockaddr_in6 sin6;
229 
230 	KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum"));
231 	rh = rt_tables_get_rnh(fibnum, AF_INET6);
232 	if (rh == NULL)
233 		return (NULL);
234 
235 	/* TODO: radix changes */
236 	//addr = *dst6;
237 	/* Prepare lookup key */
238 	memset(&sin6, 0, sizeof(sin6));
239 	sin6.sin6_len = sizeof(struct sockaddr_in6);
240 	sin6.sin6_addr = *dst6;
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 	rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
247 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
248 		rt = RNTORT(rn);
249 		nh = rt->rt_nhop;
250 		/* Ensure route & ifp is UP */
251 		if (RT_LINK_IS_UP(nh->nh_ifp)) {
252 			if (flags & NHR_REF)
253 				nhop_ref_object(nh);
254 			return (nh);
255 		}
256 	}
257 
258 	return (NULL);
259 }
260 
261 #endif
262