xref: /freebsd/sys/netinet6/in6_fib_algo.c (revision 7b71f57f4e514a2ab7308ce4147e14d90e099ad0)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2020 Alexander V. Chernikov
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include "opt_inet6.h"
29 
30 #include <sys/param.h>
31 #include <sys/eventhandler.h>
32 #include <sys/kernel.h>
33 #include <sys/lock.h>
34 #include <sys/rmlock.h>
35 #include <sys/malloc.h>
36 #include <sys/mbuf.h>
37 #include <sys/module.h>
38 #include <sys/kernel.h>
39 #include <sys/priv.h>
40 #include <sys/proc.h>
41 #include <sys/socket.h>
42 #include <sys/socketvar.h>
43 #include <sys/sysctl.h>
44 #include <net/vnet.h>
45 
46 #include <net/if.h>
47 #include <net/if_var.h>
48 
49 #include <netinet/in.h>
50 #include <netinet/in_var.h>
51 #include <netinet/ip.h>
52 #include <netinet/ip_var.h>
53 #include <netinet/ip6.h>
54 #include <netinet6/ip6_var.h>
55 #include <netinet6/in6_fib.h>
56 
57 #include <net/route.h>
58 #include <net/route/nhop.h>
59 #include <net/route/route_ctl.h>
60 #include <net/route/route_var.h>
61 #include <net/route/fib_algo.h>
62 
63 /*
64  * Lockless radix lookup algo.
65  *
66  * Compiles immutable radix from the current routing table.
67  * Used with small amount of routes (<1000).
68  * As datastructure is immutable, it gets rebuild on each rtable change.
69  *
70  */
71 
72 #define KEY_LEN_INET6	(offsetof(struct sa_in6, sin6_addr) + sizeof(struct in6_addr))
73 #define OFF_LEN_INET6	(8 * offsetof(struct sa_in6, sin6_addr))
74 struct sa_in6 {
75 	uint8_t			sin6_len;
76 	uint8_t			sin6_family;
77 	uint8_t			pad[6];
78 	struct in6_addr		sin6_addr;
79 };
80 struct radix6_addr_entry {
81 	struct radix_node	rn[2];
82 	struct sa_in6		addr;
83 	struct nhop_object	*nhop;
84 };
85 #define	LRADIX6_ITEM_SZ	roundup2(sizeof(struct radix6_addr_entry), CACHE_LINE_SIZE)
86 
87 struct lradix6_data {
88 	struct radix_node_head	*rnh;
89 	struct fib_data		*fd;
90 	void			*mem; // raw radix_mem pointer to free
91 	void			*radix_mem;
92 	uint32_t		alloc_items;
93 	uint32_t		num_items;
94 };
95 
96 static struct nhop_object *
lradix6_lookup(void * algo_data,const struct flm_lookup_key key,uint32_t scopeid)97 lradix6_lookup(void *algo_data, const struct flm_lookup_key key, uint32_t scopeid)
98 {
99 	struct radix_node_head *rnh = (struct radix_node_head *)algo_data;
100 	struct radix6_addr_entry *ent;
101 	struct sa_in6 addr6 = {
102 		.sin6_len = KEY_LEN_INET6,
103 		.sin6_addr = *key.addr6,
104 	};
105 	if (IN6_IS_SCOPE_LINKLOCAL(key.addr6))
106 		addr6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
107 	ent = (struct radix6_addr_entry *)(rn_match(&addr6, &rnh->rh));
108 	if (ent != NULL)
109 		return (ent->nhop);
110 	return (NULL);
111 }
112 
113 static uint8_t
lradix6_get_pref(const struct rib_rtable_info * rinfo)114 lradix6_get_pref(const struct rib_rtable_info *rinfo)
115 {
116 
117 	if (rinfo->num_prefixes < 10)
118 		return (255);
119 	else if (rinfo->num_prefixes < 10000)
120 		return (255 - rinfo->num_prefixes / 40);
121 	else
122 		return (1);
123 }
124 
125 static enum flm_op_result
lradix6_init(uint32_t fibnum,struct fib_data * fd,void * _old_data,void ** _data)126 lradix6_init(uint32_t fibnum, struct fib_data *fd, void *_old_data, void **_data)
127 {
128 	struct lradix6_data *lr;
129 	struct rib_rtable_info rinfo;
130 	uint32_t count;
131 	void *mem;
132 
133 	lr = malloc(sizeof(struct lradix6_data), M_RTABLE, M_NOWAIT | M_ZERO);
134 	if (lr == NULL || !rn_inithead((void **)&lr->rnh, OFF_LEN_INET6))
135 		return (FLM_REBUILD);
136 	fib_get_rtable_info(fib_get_rh(fd), &rinfo);
137 
138 	count = rinfo.num_prefixes * 11 / 10;
139 	// count+1 adds at least 1 cache line
140 	mem = malloc((count + 1) * LRADIX6_ITEM_SZ, M_RTABLE, M_NOWAIT | M_ZERO);
141 	if (mem == NULL)
142 		return (FLM_REBUILD);
143 	lr->mem = mem;
144 	lr->radix_mem = (void *)roundup2((uintptr_t)mem, CACHE_LINE_SIZE);
145 	lr->alloc_items = count;
146 	lr->fd = fd;
147 
148 	*_data = lr;
149 
150 	return (FLM_SUCCESS);
151 }
152 
153 static void
lradix6_destroy(void * _data)154 lradix6_destroy(void *_data)
155 {
156 	struct lradix6_data *lr = (struct lradix6_data *)_data;
157 
158 	if (lr->rnh != NULL)
159 		rn_detachhead((void **)&lr->rnh);
160 	if (lr->mem != NULL)
161 		free(lr->mem, M_RTABLE);
162 	free(lr, M_RTABLE);
163 }
164 
165 static enum flm_op_result
lradix6_add_route_cb(struct rtentry * rt,void * _data)166 lradix6_add_route_cb(struct rtentry *rt, void *_data)
167 {
168 	struct lradix6_data *lr = (struct lradix6_data *)_data;
169 	struct radix6_addr_entry *ae;
170 	struct sockaddr_in6 *rt_dst, *rt_mask;
171 	struct sa_in6 mask;
172 	struct radix_node *rn;
173 	struct nhop_object *nh;
174 
175 	nh = rt_get_raw_nhop(rt);
176 
177 	if (lr->num_items >= lr->alloc_items)
178 		return (FLM_REBUILD);
179 
180 	ae = (struct radix6_addr_entry *)((char *)lr->radix_mem + lr->num_items * LRADIX6_ITEM_SZ);
181 	lr->num_items++;
182 
183 	ae->nhop = nh;
184 
185 	rt_dst = (struct sockaddr_in6 *)rt_key(rt);
186 	rt_mask = (struct sockaddr_in6 *)rt_mask(rt);
187 
188 	ae->addr.sin6_len = KEY_LEN_INET6;
189 	ae->addr.sin6_addr = rt_dst->sin6_addr;
190 
191 	if (rt_mask != NULL) {
192 		bzero(&mask, sizeof(mask));
193 		mask.sin6_len = KEY_LEN_INET6;
194 		mask.sin6_addr = rt_mask->sin6_addr;
195 		rt_mask = (struct sockaddr_in6 *)&mask;
196 	}
197 
198 	rn = lr->rnh->rnh_addaddr((struct sockaddr *)&ae->addr,
199 	    (struct sockaddr *)rt_mask, &lr->rnh->rh, ae->rn);
200 	if (rn == NULL)
201 		return (FLM_REBUILD);
202 
203 	return (FLM_SUCCESS);
204 }
205 
206 static enum flm_op_result
lradix6_end_dump(void * _data,struct fib_dp * dp)207 lradix6_end_dump(void *_data, struct fib_dp *dp)
208 {
209 	struct lradix6_data *lr = (struct lradix6_data *)_data;
210 
211 	dp->f = lradix6_lookup;
212 	dp->arg = lr->rnh;
213 
214 	return (FLM_SUCCESS);
215 }
216 
217 static enum flm_op_result
lradix6_change_cb(struct rib_head * rnh,struct rib_cmd_info * rc,void * _data)218 lradix6_change_cb(struct rib_head *rnh, struct rib_cmd_info *rc,
219     void *_data)
220 {
221 
222 	return (FLM_REBUILD);
223 }
224 
225 struct fib_lookup_module flm_radix6_lockless = {
226 	.flm_name = "radix6_lockless",
227 	.flm_family = AF_INET6,
228 	.flm_init_cb = lradix6_init,
229 	.flm_destroy_cb = lradix6_destroy,
230 	.flm_dump_rib_item_cb = lradix6_add_route_cb,
231 	.flm_dump_end_cb = lradix6_end_dump,
232 	.flm_change_rib_item_cb = lradix6_change_cb,
233 	.flm_get_pref = lradix6_get_pref,
234 };
235 
236 /*
237  * Fallback lookup algorithm.
238  * This is a simple wrapper around system radix.
239  */
240 
241 struct radix6_data {
242 	struct fib_data *fd;
243 	struct rib_head *rh;
244 };
245 
246 static struct nhop_object *
radix6_lookup(void * algo_data,const struct flm_lookup_key key,uint32_t scopeid)247 radix6_lookup(void *algo_data, const struct flm_lookup_key key, uint32_t scopeid)
248 {
249 	RIB_RLOCK_TRACKER;
250 	struct rib_head *rh = (struct rib_head *)algo_data;
251 	struct radix_node *rn;
252 	struct nhop_object *nh;
253 
254 	/* Prepare lookup key */
255 	struct sockaddr_in6 sin6 = {
256 		.sin6_family = AF_INET6,
257 		.sin6_len = sizeof(struct sockaddr_in6),
258 		.sin6_addr = *key.addr6,
259 	};
260 	if (IN6_IS_SCOPE_LINKLOCAL(key.addr6))
261 		sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
262 
263 	nh = NULL;
264 	RIB_RLOCK(rh);
265 	rn = rn_match((void *)&sin6, &rh->head);
266 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0))
267 		nh = (RNTORT(rn))->rt_nhop;
268 	RIB_RUNLOCK(rh);
269 
270 	return (nh);
271 }
272 
273 struct nhop_object *
fib6_radix_lookup_nh(uint32_t fibnum,const struct in6_addr * dst6,uint32_t scopeid)274 fib6_radix_lookup_nh(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid)
275 {
276 	struct rib_head *rh = rh = rt_tables_get_rnh(fibnum, AF_INET6);
277 	const struct flm_lookup_key key = { .addr6 = dst6 };
278 
279 	if (rh == NULL)
280 		return (NULL);
281 
282 	return (radix6_lookup(rh, key, scopeid));
283 }
284 
285 static uint8_t
radix6_get_pref(const struct rib_rtable_info * rinfo)286 radix6_get_pref(const struct rib_rtable_info *rinfo)
287 {
288 
289 	return (50);
290 }
291 
292 static enum flm_op_result
radix6_init(uint32_t fibnum,struct fib_data * fd,void * _old_data,void ** _data)293 radix6_init(uint32_t fibnum, struct fib_data *fd, void *_old_data, void **_data)
294 {
295 	struct radix6_data *r6;
296 
297 	r6 = malloc(sizeof(struct radix6_data), M_RTABLE, M_NOWAIT | M_ZERO);
298 	if (r6 == NULL)
299 		return (FLM_REBUILD);
300 	r6->fd = fd;
301 	r6->rh = fib_get_rh(fd);
302 
303 	*_data = r6;
304 
305 	return (FLM_SUCCESS);
306 }
307 
308 static void
radix6_destroy(void * _data)309 radix6_destroy(void *_data)
310 {
311 
312 	free(_data, M_RTABLE);
313 }
314 
315 static enum flm_op_result
radix6_add_route_cb(struct rtentry * rt,void * _data)316 radix6_add_route_cb(struct rtentry *rt, void *_data)
317 {
318 
319 	return (FLM_SUCCESS);
320 }
321 
322 static enum flm_op_result
radix6_end_dump(void * _data,struct fib_dp * dp)323 radix6_end_dump(void *_data, struct fib_dp *dp)
324 {
325 	struct radix6_data *r6 = (struct radix6_data *)_data;
326 
327 	dp->f = radix6_lookup;
328 	dp->arg = r6->rh;
329 
330 	return (FLM_SUCCESS);
331 }
332 
333 static enum flm_op_result
radix6_change_cb(struct rib_head * rnh,struct rib_cmd_info * rc,void * _data)334 radix6_change_cb(struct rib_head *rnh, struct rib_cmd_info *rc,
335     void *_data)
336 {
337 
338 	return (FLM_SUCCESS);
339 }
340 
341 struct fib_lookup_module flm_radix6 = {
342 	.flm_name = "radix6",
343 	.flm_family = AF_INET6,
344 	.flm_init_cb = radix6_init,
345 	.flm_destroy_cb = radix6_destroy,
346 	.flm_dump_rib_item_cb = radix6_add_route_cb,
347 	.flm_dump_end_cb = radix6_end_dump,
348 	.flm_change_rib_item_cb = radix6_change_cb,
349 	.flm_get_pref = radix6_get_pref,
350 };
351 
352 static void
fib6_algo_init(void * dummy __unused)353 fib6_algo_init(void *dummy __unused)
354 {
355 
356 	fib_module_register(&flm_radix6_lockless);
357 	fib_module_register(&flm_radix6);
358 }
359 SYSINIT(fib6_algo_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, fib6_algo_init, NULL);
360