xref: /freebsd/sys/netinet6/in6_fib_algo.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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 <sys/cdefs.h>
29 #include "opt_inet6.h"
30 
31 #include <sys/param.h>
32 #include <sys/eventhandler.h>
33 #include <sys/kernel.h>
34 #include <sys/lock.h>
35 #include <sys/rmlock.h>
36 #include <sys/malloc.h>
37 #include <sys/mbuf.h>
38 #include <sys/module.h>
39 #include <sys/kernel.h>
40 #include <sys/priv.h>
41 #include <sys/proc.h>
42 #include <sys/socket.h>
43 #include <sys/socketvar.h>
44 #include <sys/sysctl.h>
45 #include <net/vnet.h>
46 
47 #include <net/if.h>
48 #include <net/if_var.h>
49 
50 #include <netinet/in.h>
51 #include <netinet/in_var.h>
52 #include <netinet/ip.h>
53 #include <netinet/ip_var.h>
54 #include <netinet/ip6.h>
55 #include <netinet6/ip6_var.h>
56 #include <netinet6/in6_fib.h>
57 
58 #include <net/route.h>
59 #include <net/route/nhop.h>
60 #include <net/route/route_ctl.h>
61 #include <net/route/route_var.h>
62 #include <net/route/fib_algo.h>
63 
64 /*
65  * Lockless radix lookup algo.
66  *
67  * Compiles immutable radix from the current routing table.
68  * Used with small amount of routes (<1000).
69  * As datastructure is immutable, it gets rebuild on each rtable change.
70  *
71  */
72 
73 #define KEY_LEN_INET6	(offsetof(struct sa_in6, sin6_addr) + sizeof(struct in6_addr))
74 #define OFF_LEN_INET6	(8 * offsetof(struct sa_in6, sin6_addr))
75 struct sa_in6 {
76 	uint8_t			sin6_len;
77 	uint8_t			sin6_family;
78 	uint8_t			pad[6];
79 	struct in6_addr		sin6_addr;
80 };
81 struct radix6_addr_entry {
82 	struct radix_node	rn[2];
83 	struct sa_in6		addr;
84 	struct nhop_object	*nhop;
85 };
86 #define	LRADIX6_ITEM_SZ	roundup2(sizeof(struct radix6_addr_entry), CACHE_LINE_SIZE)
87 
88 struct lradix6_data {
89 	struct radix_node_head	*rnh;
90 	struct fib_data		*fd;
91 	void			*mem; // raw radix_mem pointer to free
92 	void			*radix_mem;
93 	uint32_t		alloc_items;
94 	uint32_t		num_items;
95 };
96 
97 static struct nhop_object *
98 lradix6_lookup(void *algo_data, const struct flm_lookup_key key, uint32_t scopeid)
99 {
100 	struct radix_node_head *rnh = (struct radix_node_head *)algo_data;
101 	struct radix6_addr_entry *ent;
102 	struct sa_in6 addr6 = {
103 		.sin6_len = KEY_LEN_INET6,
104 		.sin6_addr = *key.addr6,
105 	};
106 	if (IN6_IS_SCOPE_LINKLOCAL(key.addr6))
107 		addr6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
108 	ent = (struct radix6_addr_entry *)(rn_match(&addr6, &rnh->rh));
109 	if (ent != NULL)
110 		return (ent->nhop);
111 	return (NULL);
112 }
113 
114 static uint8_t
115 lradix6_get_pref(const struct rib_rtable_info *rinfo)
116 {
117 
118 	if (rinfo->num_prefixes < 10)
119 		return (255);
120 	else if (rinfo->num_prefixes < 10000)
121 		return (255 - rinfo->num_prefixes / 40);
122 	else
123 		return (1);
124 }
125 
126 static enum flm_op_result
127 lradix6_init(uint32_t fibnum, struct fib_data *fd, void *_old_data, void **_data)
128 {
129 	struct lradix6_data *lr;
130 	struct rib_rtable_info rinfo;
131 	uint32_t count;
132 	void *mem;
133 
134 	lr = malloc(sizeof(struct lradix6_data), M_RTABLE, M_NOWAIT | M_ZERO);
135 	if (lr == NULL || !rn_inithead((void **)&lr->rnh, OFF_LEN_INET6))
136 		return (FLM_REBUILD);
137 	fib_get_rtable_info(fib_get_rh(fd), &rinfo);
138 
139 	count = rinfo.num_prefixes * 11 / 10;
140 	// count+1 adds at least 1 cache line
141 	mem = malloc((count + 1) * LRADIX6_ITEM_SZ, M_RTABLE, M_NOWAIT | M_ZERO);
142 	if (mem == NULL)
143 		return (FLM_REBUILD);
144 	lr->mem = mem;
145 	lr->radix_mem = (void *)roundup2((uintptr_t)mem, CACHE_LINE_SIZE);
146 	lr->alloc_items = count;
147 	lr->fd = fd;
148 
149 	*_data = lr;
150 
151 	return (FLM_SUCCESS);
152 }
153 
154 static void
155 lradix6_destroy(void *_data)
156 {
157 	struct lradix6_data *lr = (struct lradix6_data *)_data;
158 
159 	if (lr->rnh != NULL)
160 		rn_detachhead((void **)&lr->rnh);
161 	if (lr->mem != NULL)
162 		free(lr->mem, M_RTABLE);
163 	free(lr, M_RTABLE);
164 }
165 
166 static enum flm_op_result
167 lradix6_add_route_cb(struct rtentry *rt, void *_data)
168 {
169 	struct lradix6_data *lr = (struct lradix6_data *)_data;
170 	struct radix6_addr_entry *ae;
171 	struct sockaddr_in6 *rt_dst, *rt_mask;
172 	struct sa_in6 mask;
173 	struct radix_node *rn;
174 	struct nhop_object *nh;
175 
176 	nh = rt_get_raw_nhop(rt);
177 
178 	if (lr->num_items >= lr->alloc_items)
179 		return (FLM_REBUILD);
180 
181 	ae = (struct radix6_addr_entry *)((char *)lr->radix_mem + lr->num_items * LRADIX6_ITEM_SZ);
182 	lr->num_items++;
183 
184 	ae->nhop = nh;
185 
186 	rt_dst = (struct sockaddr_in6 *)rt_key(rt);
187 	rt_mask = (struct sockaddr_in6 *)rt_mask(rt);
188 
189 	ae->addr.sin6_len = KEY_LEN_INET6;
190 	ae->addr.sin6_addr = rt_dst->sin6_addr;
191 
192 	if (rt_mask != NULL) {
193 		bzero(&mask, sizeof(mask));
194 		mask.sin6_len = KEY_LEN_INET6;
195 		mask.sin6_addr = rt_mask->sin6_addr;
196 		rt_mask = (struct sockaddr_in6 *)&mask;
197 	}
198 
199 	rn = lr->rnh->rnh_addaddr((struct sockaddr *)&ae->addr,
200 	    (struct sockaddr *)rt_mask, &lr->rnh->rh, ae->rn);
201 	if (rn == NULL)
202 		return (FLM_REBUILD);
203 
204 	return (FLM_SUCCESS);
205 }
206 
207 static enum flm_op_result
208 lradix6_end_dump(void *_data, struct fib_dp *dp)
209 {
210 	struct lradix6_data *lr = (struct lradix6_data *)_data;
211 
212 	dp->f = lradix6_lookup;
213 	dp->arg = lr->rnh;
214 
215 	return (FLM_SUCCESS);
216 }
217 
218 static enum flm_op_result
219 lradix6_change_cb(struct rib_head *rnh, struct rib_cmd_info *rc,
220     void *_data)
221 {
222 
223 	return (FLM_REBUILD);
224 }
225 
226 struct fib_lookup_module flm_radix6_lockless = {
227 	.flm_name = "radix6_lockless",
228 	.flm_family = AF_INET6,
229 	.flm_init_cb = lradix6_init,
230 	.flm_destroy_cb = lradix6_destroy,
231 	.flm_dump_rib_item_cb = lradix6_add_route_cb,
232 	.flm_dump_end_cb = lradix6_end_dump,
233 	.flm_change_rib_item_cb = lradix6_change_cb,
234 	.flm_get_pref = lradix6_get_pref,
235 };
236 
237 /*
238  * Fallback lookup algorithm.
239  * This is a simple wrapper around system radix.
240  */
241 
242 struct radix6_data {
243 	struct fib_data *fd;
244 	struct rib_head *rh;
245 };
246 
247 static struct nhop_object *
248 radix6_lookup(void *algo_data, const struct flm_lookup_key key, uint32_t scopeid)
249 {
250 	RIB_RLOCK_TRACKER;
251 	struct rib_head *rh = (struct rib_head *)algo_data;
252 	struct radix_node *rn;
253 	struct nhop_object *nh;
254 
255 	/* Prepare lookup key */
256 	struct sockaddr_in6 sin6 = {
257 		.sin6_family = AF_INET6,
258 		.sin6_len = sizeof(struct sockaddr_in6),
259 		.sin6_addr = *key.addr6,
260 	};
261 	if (IN6_IS_SCOPE_LINKLOCAL(key.addr6))
262 		sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
263 
264 	nh = NULL;
265 	RIB_RLOCK(rh);
266 	rn = rn_match((void *)&sin6, &rh->head);
267 	if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0))
268 		nh = (RNTORT(rn))->rt_nhop;
269 	RIB_RUNLOCK(rh);
270 
271 	return (nh);
272 }
273 
274 struct nhop_object *
275 fib6_radix_lookup_nh(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid)
276 {
277 	struct rib_head *rh = rh = rt_tables_get_rnh(fibnum, AF_INET6);
278 	const struct flm_lookup_key key = { .addr6 = dst6 };
279 
280 	if (rh == NULL)
281 		return (NULL);
282 
283 	return (radix6_lookup(rh, key, scopeid));
284 }
285 
286 static uint8_t
287 radix6_get_pref(const struct rib_rtable_info *rinfo)
288 {
289 
290 	return (50);
291 }
292 
293 static enum flm_op_result
294 radix6_init(uint32_t fibnum, struct fib_data *fd, void *_old_data, void **_data)
295 {
296 	struct radix6_data *r6;
297 
298 	r6 = malloc(sizeof(struct radix6_data), M_RTABLE, M_NOWAIT | M_ZERO);
299 	if (r6 == NULL)
300 		return (FLM_REBUILD);
301 	r6->fd = fd;
302 	r6->rh = fib_get_rh(fd);
303 
304 	*_data = r6;
305 
306 	return (FLM_SUCCESS);
307 }
308 
309 static void
310 radix6_destroy(void *_data)
311 {
312 
313 	free(_data, M_RTABLE);
314 }
315 
316 static enum flm_op_result
317 radix6_add_route_cb(struct rtentry *rt, void *_data)
318 {
319 
320 	return (FLM_SUCCESS);
321 }
322 
323 static enum flm_op_result
324 radix6_end_dump(void *_data, struct fib_dp *dp)
325 {
326 	struct radix6_data *r6 = (struct radix6_data *)_data;
327 
328 	dp->f = radix6_lookup;
329 	dp->arg = r6->rh;
330 
331 	return (FLM_SUCCESS);
332 }
333 
334 static enum flm_op_result
335 radix6_change_cb(struct rib_head *rnh, struct rib_cmd_info *rc,
336     void *_data)
337 {
338 
339 	return (FLM_SUCCESS);
340 }
341 
342 struct fib_lookup_module flm_radix6 = {
343 	.flm_name = "radix6",
344 	.flm_family = AF_INET6,
345 	.flm_init_cb = radix6_init,
346 	.flm_destroy_cb = radix6_destroy,
347 	.flm_dump_rib_item_cb = radix6_add_route_cb,
348 	.flm_dump_end_cb = radix6_end_dump,
349 	.flm_change_rib_item_cb = radix6_change_cb,
350 	.flm_get_pref = radix6_get_pref,
351 };
352 
353 static void
354 fib6_algo_init(void)
355 {
356 
357 	fib_module_register(&flm_radix6_lockless);
358 	fib_module_register(&flm_radix6);
359 }
360 SYSINIT(fib6_algo_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, fib6_algo_init, NULL);
361