xref: /freebsd/sys/netinet6/in6_fib.c (revision a4bcd20486f8c20cc875b39bc75aa0d5a047373f)
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 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/lock.h>
40 #include <sys/rmlock.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/sysctl.h>
45 #include <sys/kernel.h>
46 
47 #include <net/if.h>
48 #include <net/if_var.h>
49 #include <net/if_dl.h>
50 #include <net/route.h>
51 #include <net/route/route_ctl.h>
52 #include <net/route/route_var.h>
53 #include <net/route/nhop.h>
54 #include <net/vnet.h>
55 
56 #include <netinet/in.h>
57 #include <netinet/in_var.h>
58 #include <netinet/ip_mroute.h>
59 #include <netinet/ip6.h>
60 #include <netinet6/in6_fib.h>
61 #include <netinet6/in6_var.h>
62 #include <netinet6/nd6.h>
63 #include <netinet6/scope6_var.h>
64 
65 #include <net/if_types.h>
66 
67 #ifdef INET6
68 
69 CHK_STRUCT_ROUTE_COMPAT(struct route_in6, ro_dst);
70 
71 /*
72  * Looks up path in fib @fibnum specified by @dst.
73  * Assumes scope is deembedded and provided in @scopeid.
74  *
75  * Returns path nexthop on success. Nexthop is safe to use
76  *  within the current network epoch. If longer lifetime is required,
77  *  one needs to pass NHR_REF as a flag. This will return referenced
78  *  nexthop.
79  */
80 struct nhop_object *
81 fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6,
82     uint32_t scopeid, uint32_t flags, uint32_t flowid)
83 {
84 	RIB_RLOCK_TRACKER;
85 	struct rib_head *rh;
86 	struct radix_node *rn;
87 	struct nhop_object *nh;
88 	struct sockaddr_in6 sin6;
89 
90 	KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum"));
91 	rh = rt_tables_get_rnh(fibnum, AF_INET6);
92 	if (rh == NULL)
93 		return (NULL);
94 
95 	/* TODO: radix changes */
96 	//addr = *dst6;
97 	/* Prepare lookup key */
98 	memset(&sin6, 0, sizeof(sin6));
99 	sin6.sin6_len = sizeof(struct sockaddr_in6);
100 	sin6.sin6_addr = *dst6;
101 
102 	/* Assume scopeid is valid and embed it directly */
103 	if (IN6_IS_SCOPE_LINKLOCAL(dst6))
104 		sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
105 
106 	RIB_RLOCK(rh);
107 	rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
108 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
109 		nh = nhop_select((RNTORT(rn))->rt_nhop, flowid);
110 		/* Ensure route & ifp is UP */
111 		if (RT_LINK_IS_UP(nh->nh_ifp)) {
112 			if (flags & NHR_REF)
113 				nhop_ref_object(nh);
114 			RIB_RUNLOCK(rh);
115 			return (nh);
116 		}
117 	}
118 	RIB_RUNLOCK(rh);
119 
120 	RTSTAT_INC(rts_unreach);
121 	return (NULL);
122 }
123 
124 inline static int
125 check_urpf_nhop(const struct nhop_object *nh, uint32_t flags,
126     const struct ifnet *src_if)
127 {
128 
129 	if (src_if != NULL && nh->nh_aifp == src_if) {
130 		return (1);
131 	}
132 	if (src_if == NULL) {
133 		if ((flags & NHR_NODEFAULT) == 0)
134 			return (1);
135 		else if ((nh->nh_flags & NHF_DEFAULT) == 0)
136 			return (1);
137 	}
138 
139 	return (0);
140 }
141 
142 static int
143 check_urpf(struct nhop_object *nh, uint32_t flags,
144     const struct ifnet *src_if)
145 {
146 #ifdef ROUTE_MPATH
147 	if (NH_IS_NHGRP(nh)) {
148 		struct weightened_nhop *wn;
149 		uint32_t num_nhops;
150 		wn = nhgrp_get_nhops((struct nhgrp_object *)nh, &num_nhops);
151 		for (int i = 0; i < num_nhops; i++) {
152 			if (check_urpf_nhop(wn[i].nh, flags, src_if) != 0)
153 				return (1);
154 		}
155 		return (0);
156 	} else
157 #endif
158 		return (check_urpf_nhop(nh, flags, src_if));
159 }
160 
161 /*
162  * Performs reverse path forwarding lookup.
163  * If @src_if is non-zero, verifies that at least 1 path goes via
164  *   this interface.
165  * If @src_if is zero, verifies that route exist.
166  * if @flags contains NHR_NOTDEFAULT, do not consider default route.
167  *
168  * Returns 1 if route matching conditions is found, 0 otherwise.
169  */
170 int
171 fib6_check_urpf(uint32_t fibnum, const struct in6_addr *dst6,
172     uint32_t scopeid, uint32_t flags, const struct ifnet *src_if)
173 {
174 	RIB_RLOCK_TRACKER;
175 	struct rib_head *rh;
176 	struct radix_node *rn;
177 	struct sockaddr_in6 sin6;
178 	int ret;
179 
180 	KASSERT((fibnum < rt_numfibs), ("fib6_check_urpf: bad fibnum"));
181 	rh = rt_tables_get_rnh(fibnum, AF_INET6);
182 	if (rh == NULL)
183 		return (0);
184 
185 	/* TODO: radix changes */
186 	/* Prepare lookup key */
187 	memset(&sin6, 0, sizeof(sin6));
188 	sin6.sin6_len = sizeof(struct sockaddr_in6);
189 	sin6.sin6_addr = *dst6;
190 
191 	/* Assume scopeid is valid and embed it directly */
192 	if (IN6_IS_SCOPE_LINKLOCAL(dst6))
193 		sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
194 
195 	RIB_RLOCK(rh);
196 	rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
197 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
198 		ret = check_urpf(RNTORT(rn)->rt_nhop, flags, src_if);
199 		RIB_RUNLOCK(rh);
200 		return (ret);
201 	}
202 	RIB_RUNLOCK(rh);
203 
204 	return (0);
205 }
206 
207 struct nhop_object *
208 fib6_lookup_debugnet(uint32_t fibnum, const struct in6_addr *dst6,
209     uint32_t scopeid, uint32_t flags)
210 {
211 	struct rib_head *rh;
212 	struct radix_node *rn;
213 	struct nhop_object *nh;
214 	struct sockaddr_in6 sin6;
215 
216 	KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum"));
217 	rh = rt_tables_get_rnh(fibnum, AF_INET6);
218 	if (rh == NULL)
219 		return (NULL);
220 
221 	/* TODO: radix changes */
222 	//addr = *dst6;
223 	/* Prepare lookup key */
224 	memset(&sin6, 0, sizeof(sin6));
225 	sin6.sin6_len = sizeof(struct sockaddr_in6);
226 	sin6.sin6_addr = *dst6;
227 
228 	/* Assume scopeid is valid and embed it directly */
229 	if (IN6_IS_SCOPE_LINKLOCAL(dst6))
230 		sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
231 
232 	rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
233 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
234 		nh = nhop_select((RNTORT(rn))->rt_nhop, 0);
235 		/* Ensure route & ifp is UP */
236 		if (RT_LINK_IS_UP(nh->nh_ifp)) {
237 			if (flags & NHR_REF)
238 				nhop_ref_object(nh);
239 			return (nh);
240 		}
241 	}
242 
243 	return (NULL);
244 }
245 
246 #endif
247