xref: /freebsd/sys/netinet6/in6_fib.c (revision 8ecd87a3e7f5503951d37eab034cb330a1c6ec86)
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/toeplitz.h>
55 #include <net/vnet.h>
56 
57 #include <netinet/in.h>
58 #include <netinet/in_var.h>
59 #include <netinet/ip_mroute.h>
60 #include <netinet/ip6.h>
61 #include <netinet6/in6_fib.h>
62 #include <netinet6/in6_var.h>
63 #include <netinet6/nd6.h>
64 #include <netinet6/scope6_var.h>
65 
66 #include <net/if_types.h>
67 
68 #ifdef INET6
69 
70 CHK_STRUCT_ROUTE_COMPAT(struct route_in6, ro_dst);
71 
72 #ifdef ROUTE_MPATH
73 struct _hash_5tuple_ipv6 {
74 	struct in6_addr src;
75 	struct in6_addr dst;
76 	unsigned short src_port;
77 	unsigned short dst_port;
78 	char proto;
79 	char spare[3];
80 };
81 _Static_assert(sizeof(struct _hash_5tuple_ipv6) == 40,
82     "_hash_5tuple_ipv6 size is wrong");
83 
84 uint32_t
85 fib6_calc_software_hash(const struct in6_addr *src, const struct in6_addr *dst,
86     unsigned short src_port, unsigned short dst_port, char proto,
87     uint32_t *phashtype)
88 {
89 	struct _hash_5tuple_ipv6 data;
90 
91 	data.src = *src;
92 	data.dst = *dst;
93 	data.src_port = src_port;
94 	data.dst_port = dst_port;
95 	data.proto = proto;
96 	data.spare[0] = data.spare[1] = data.spare[2] = 0;
97 
98 	*phashtype = M_HASHTYPE_OPAQUE_HASH;
99 
100 	return (toeplitz_hash(MPATH_ENTROPY_KEY_LEN, mpath_entropy_key,
101 	  sizeof(data), (uint8_t *)&data));
102 }
103 #endif
104 
105 /*
106  * Looks up path in fib @fibnum specified by @dst.
107  * Assumes scope is deembedded and provided in @scopeid.
108  *
109  * Returns path nexthop on success. Nexthop is safe to use
110  *  within the current network epoch. If longer lifetime is required,
111  *  one needs to pass NHR_REF as a flag. This will return referenced
112  *  nexthop.
113  */
114 struct nhop_object *
115 fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6,
116     uint32_t scopeid, uint32_t flags, uint32_t flowid)
117 {
118 	RIB_RLOCK_TRACKER;
119 	struct rib_head *rh;
120 	struct radix_node *rn;
121 	struct nhop_object *nh;
122 	struct sockaddr_in6 sin6;
123 
124 	KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum"));
125 	rh = rt_tables_get_rnh(fibnum, AF_INET6);
126 	if (rh == NULL)
127 		return (NULL);
128 
129 	/* TODO: radix changes */
130 	//addr = *dst6;
131 	/* Prepare lookup key */
132 	memset(&sin6, 0, sizeof(sin6));
133 	sin6.sin6_len = sizeof(struct sockaddr_in6);
134 	sin6.sin6_addr = *dst6;
135 
136 	/* Assume scopeid is valid and embed it directly */
137 	if (IN6_IS_SCOPE_LINKLOCAL(dst6))
138 		sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
139 
140 	RIB_RLOCK(rh);
141 	rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
142 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
143 		nh = nhop_select((RNTORT(rn))->rt_nhop, flowid);
144 		/* Ensure route & ifp is UP */
145 		if (RT_LINK_IS_UP(nh->nh_ifp)) {
146 			if (flags & NHR_REF)
147 				nhop_ref_object(nh);
148 			RIB_RUNLOCK(rh);
149 			return (nh);
150 		}
151 	}
152 	RIB_RUNLOCK(rh);
153 
154 	RTSTAT_INC(rts_unreach);
155 	return (NULL);
156 }
157 
158 inline static int
159 check_urpf_nhop(const struct nhop_object *nh, uint32_t flags,
160     const struct ifnet *src_if)
161 {
162 
163 	if (src_if != NULL && nh->nh_aifp == src_if) {
164 		return (1);
165 	}
166 	if (src_if == NULL) {
167 		if ((flags & NHR_NODEFAULT) == 0)
168 			return (1);
169 		else if ((nh->nh_flags & NHF_DEFAULT) == 0)
170 			return (1);
171 	}
172 
173 	return (0);
174 }
175 
176 static int
177 check_urpf(struct nhop_object *nh, uint32_t flags,
178     const struct ifnet *src_if)
179 {
180 #ifdef ROUTE_MPATH
181 	if (NH_IS_NHGRP(nh)) {
182 		struct weightened_nhop *wn;
183 		uint32_t num_nhops;
184 		wn = nhgrp_get_nhops((struct nhgrp_object *)nh, &num_nhops);
185 		for (int i = 0; i < num_nhops; i++) {
186 			if (check_urpf_nhop(wn[i].nh, flags, src_if) != 0)
187 				return (1);
188 		}
189 		return (0);
190 	} else
191 #endif
192 		return (check_urpf_nhop(nh, flags, src_if));
193 }
194 
195 /*
196  * Performs reverse path forwarding lookup.
197  * If @src_if is non-zero, verifies that at least 1 path goes via
198  *   this interface.
199  * If @src_if is zero, verifies that route exist.
200  * if @flags contains NHR_NOTDEFAULT, do not consider default route.
201  *
202  * Returns 1 if route matching conditions is found, 0 otherwise.
203  */
204 int
205 fib6_check_urpf(uint32_t fibnum, const struct in6_addr *dst6,
206     uint32_t scopeid, uint32_t flags, const struct ifnet *src_if)
207 {
208 	RIB_RLOCK_TRACKER;
209 	struct rib_head *rh;
210 	struct radix_node *rn;
211 	struct sockaddr_in6 sin6;
212 	int ret;
213 
214 	KASSERT((fibnum < rt_numfibs), ("fib6_check_urpf: bad fibnum"));
215 	rh = rt_tables_get_rnh(fibnum, AF_INET6);
216 	if (rh == NULL)
217 		return (0);
218 
219 	/* TODO: radix changes */
220 	/* Prepare lookup key */
221 	memset(&sin6, 0, sizeof(sin6));
222 	sin6.sin6_len = sizeof(struct sockaddr_in6);
223 	sin6.sin6_addr = *dst6;
224 
225 	/* Assume scopeid is valid and embed it directly */
226 	if (IN6_IS_SCOPE_LINKLOCAL(dst6))
227 		sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
228 
229 	RIB_RLOCK(rh);
230 	rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
231 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
232 		ret = check_urpf(RNTORT(rn)->rt_nhop, flags, src_if);
233 		RIB_RUNLOCK(rh);
234 		return (ret);
235 	}
236 	RIB_RUNLOCK(rh);
237 
238 	return (0);
239 }
240 
241 struct nhop_object *
242 fib6_lookup_debugnet(uint32_t fibnum, const struct in6_addr *dst6,
243     uint32_t scopeid, uint32_t flags)
244 {
245 	struct rib_head *rh;
246 	struct radix_node *rn;
247 	struct nhop_object *nh;
248 	struct sockaddr_in6 sin6;
249 
250 	KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum"));
251 	rh = rt_tables_get_rnh(fibnum, AF_INET6);
252 	if (rh == NULL)
253 		return (NULL);
254 
255 	/* TODO: radix changes */
256 	//addr = *dst6;
257 	/* Prepare lookup key */
258 	memset(&sin6, 0, sizeof(sin6));
259 	sin6.sin6_len = sizeof(struct sockaddr_in6);
260 	sin6.sin6_addr = *dst6;
261 
262 	/* Assume scopeid is valid and embed it directly */
263 	if (IN6_IS_SCOPE_LINKLOCAL(dst6))
264 		sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
265 
266 	rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
267 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
268 		nh = nhop_select((RNTORT(rn))->rt_nhop, 0);
269 		/* Ensure route & ifp is UP */
270 		if (RT_LINK_IS_UP(nh->nh_ifp)) {
271 			if (flags & NHR_REF)
272 				nhop_ref_object(nh);
273 			return (nh);
274 		}
275 	}
276 
277 	return (NULL);
278 }
279 
280 #endif
281