1 /*
2 * Copyright (c) 2016-2021 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28 /*
29 * Copyright (c) 2004 Luigi Rizzo, Alessandro Cerri. All rights reserved.
30 * Copyright (c) 2004-2008 Qing Li. All rights reserved.
31 * Copyright (c) 2008 Kip Macy. All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 * notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 * notice, this list of conditions and the following disclaimer in the
40 * documentation and/or other materials provided with the distribution.
41 *
42 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
43 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
44 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
45 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
46 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
47 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
48 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
49 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
50 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
51 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * SUCH DAMAGE.
53 */
54 #include <sys/cdefs.h>
55
56 #ifndef _NET_IF_LLATBL_H_
57 #define _NET_IF_LLATBL_H_
58
59 #include <netinet/in.h>
60 #include <net/if_dl.h>
61 #include <kern/locks.h>
62 #include <kern/thread_call.h>
63 #include <sys/eventhandler.h>
64
65 struct ifnet;
66 struct sysctl_req;
67 struct rt_msghdr;
68 struct rt_addrinfo;
69
70 struct llentry;
71 LIST_HEAD(llentries, llentry);
72
73 extern lck_rw_t lltable_rwlock;
74 #define LLTABLE_RLOCK() lck_rw_lock_shared(&lltable_rwlock)
75 #define LLTABLE_RUNLOCK() lck_rw_done(&lltable_rwlock)
76 #define LLTABLE_WLOCK() lck_rw_lock_exclusive(&lltable_rwlock)
77 #define LLTABLE_WUNLOCK() lck_rw_done(&lltable_rwlock)
78 #define LLTABLE_LOCK_ASSERT() LCK_RW_ASSERT(&lltable_rwlock, LCK_RW_ASSERT_EXCLUSIVE)
79
80 #define LLE_MAX_LINKHDR 24 /* Full IB header */
81 /*
82 * Code referencing llentry must at least hold
83 * a shared lock
84 */
85 struct llentry {
86 LIST_ENTRY(llentry) lle_next;
87 union {
88 struct in_addr addr4;
89 struct in6_addr addr6;
90 } r_l3addr;
91 #if 0
92 char r_linkdata[LLE_MAX_LINKHDR]; /* L2 data */
93 uint8_t r_hdrlen; /* length for LL header */
94 uint8_t spare0[3];
95 #endif
96 uint16_t r_flags; /* LLE runtime flags */
97 uint16_t r_skip_req; /* feedback from fast path */
98
99 struct lltable *lle_tbl;
100 struct llentries *lle_head;
101 void (*lle_free)(struct llentry *);
102 struct mbuf *la_hold;
103 int la_numheld; /* # of packets currently held */
104 u_int64_t la_expire;
105 uint16_t la_flags;
106 uint16_t la_asked;
107 uint16_t la_preempt;
108 int16_t ln_state; /* IPv6 has ND6_LLINFO_NOSTATE == -2 */
109 uint16_t ln_router;
110 time_t ln_ntick;
111 time_t lle_remtime; /* Real time remaining */
112 time_t lle_hittime; /* Time when r_skip_req was unset */
113 int lle_refcnt;
114 union {
115 uint64_t mac_aligned;
116 uint16_t mac16[3];
117 } ll_addr;
118 LIST_ENTRY(llentry) lle_chain; /* chain of deleted items */
119 thread_call_t lle_timer;
120 u_int64_t ln_lastused; /* last used timestamp */
121 struct if_llreach *ln_llreach; /* link-layer reachability record */
122 decl_lck_rw_data(, lle_lock);
123 decl_lck_mtx_data(, req_mtx);
124 };
125
126 extern lck_grp_t lle_lock_grp;
127 extern lck_attr_t lle_lock_attr;
128
129 #define LLE_WLOCK(lle) lck_rw_lock_exclusive(&(lle)->lle_lock)
130 #define LLE_RLOCK(lle) lck_rw_lock_shared(&(lle)->lle_lock)
131 #define LLE_WUNLOCK(lle) lck_rw_done(&(lle)->lle_lock)
132 #define LLE_RUNLOCK(lle) lck_rw_done(&(lle)->lle_lock)
133 #define LLE_DOWNGRADE(lle) lck_rw_lock_exclusive_to_shared(&(lle)->lle_lock)
134 #define LLE_TRY_UPGRADE(lle) lck_rw_lock_shared_to_exclusive(&(lle)->lle_lock)
135 #define LLE_LOCK_INIT(lle) lck_rw_init(&(lle)->lle_lock, &lle_lock_grp, &lle_lock_attr)
136 #define LLE_LOCK_DESTROY(lle) lck_rw_destroy(&(lle)->lle_lock, &lle_lock_grp)
137 #define LLE_WLOCK_ASSERT(lle) LCK_RW_ASSERT(&(lle)->lle_lock, LCK_RW_ASSERT_EXCLUSIVE)
138
139 #define LLE_REQ_INIT(lle) lck_mtx_init(&(lle)->req_mtx, &lle_lock_grp, &lle_lock_attr)
140 #define LLE_REQ_DESTROY(lle) lck_mtx_destroy(&(lle)->req_mtx, &lle_lock_grp)
141 #define LLE_REQ_LOCK(lle) lck_mtx_lock(&(lle)->req_mtx)
142 #define LLE_REQ_UNLOCK(lle) lck_mtx_unlock(&(lle)->req_mtx)
143
144 #define LLE_IS_VALID(lle) (((lle) != NULL) && ((lle) != (void *)-1))
145
146 #define LLE_ADDREF(lle) do { \
147 LLE_WLOCK_ASSERT(lle); \
148 VERIFY((lle)->lle_refcnt >= 0); \
149 (lle)->lle_refcnt++; \
150 } while (0)
151
152 #define LLE_REMREF(lle) do { \
153 LLE_WLOCK_ASSERT(lle); \
154 VERIFY((lle)->lle_refcnt > 0); \
155 (lle)->lle_refcnt--; \
156 } while (0)
157
158 #define LLE_FREE_LOCKED(lle) do { \
159 if ((lle)->lle_refcnt == 1) \
160 (lle)->lle_free(lle); \
161 else { \
162 LLE_REMREF(lle); \
163 LLE_WUNLOCK(lle); \
164 } \
165 /* guard against invalid refs */ \
166 (lle) = NULL; \
167 } while (0)
168
169 #define LLE_FREE(lle) do { \
170 LLE_WLOCK(lle); \
171 LLE_FREE_LOCKED(lle); \
172 } while (0)
173
174 typedef struct llentry *(llt_lookup_t)(struct lltable *, uint16_t flags,
175 const struct sockaddr *l3addr);
176 typedef struct llentry *(llt_alloc_t)(struct lltable *, uint16_t flags,
177 const struct sockaddr *l3addr);
178 typedef void (llt_delete_t)(struct lltable *, struct llentry *);
179 typedef void (llt_prefix_free_t)(struct lltable *,
180 const struct sockaddr *addr, const struct sockaddr *mask, uint16_t flags);
181 typedef int (llt_dump_entry_t)(struct lltable *, struct llentry *,
182 struct sysctl_req *);
183 typedef uint32_t (llt_hash_t)(const struct llentry *, uint32_t);
184 typedef int (llt_match_prefix_t)(const struct sockaddr *,
185 const struct sockaddr *, uint16_t, struct llentry *);
186 typedef void (llt_free_entry_t)(struct lltable *, struct llentry *);
187 typedef void (llt_fill_sa_entry_t)(const struct llentry *, struct sockaddr *);
188 typedef void (llt_free_tbl_t)(struct lltable *);
189 typedef void (llt_link_entry_t)(struct lltable *, struct llentry *);
190 typedef void (llt_unlink_entry_t)(struct llentry *);
191
192 typedef int (llt_foreach_cb_t)(struct lltable *, struct llentry *, void *);
193 typedef int (llt_foreach_entry_t)(struct lltable *, llt_foreach_cb_t *, void *);
194
195 struct lltable {
196 SLIST_ENTRY(lltable) llt_link;
197 int llt_af;
198 int llt_hsize;
199 struct llentries *__counted_by(llt_hsize) lle_head;
200 struct ifnet *llt_ifp;
201
202 llt_lookup_t *llt_lookup;
203 llt_alloc_t *llt_alloc_entry;
204 llt_delete_t *llt_delete_entry;
205 llt_prefix_free_t *llt_prefix_free;
206 llt_dump_entry_t *llt_dump_entry;
207 llt_hash_t *llt_hash;
208 llt_match_prefix_t *llt_match_prefix;
209 llt_free_entry_t *llt_free_entry;
210 llt_foreach_entry_t *llt_foreach_entry;
211 llt_link_entry_t *llt_link_entry;
212 llt_unlink_entry_t *llt_unlink_entry;
213 llt_fill_sa_entry_t *llt_fill_sa_entry;
214 };
215
216 /*
217 * LLentry flags
218 */
219 #define LLE_DELETED 0x0001 /* entry must be deleted */
220 #define LLE_STATIC 0x0002 /* entry is static */
221 #define LLE_IFADDR 0x0004 /* entry is interface addr */
222 #define LLE_VALID 0x0008 /* ll_addr is valid */
223 #define LLE_REDIRECT 0x0010 /* installed by redirect; has host rtentry */
224 #define LLE_PUB 0x0020 /* publish entry ??? */
225 #define LLE_LINKED 0x0040 /* linked to lookup structure */
226 /* LLE request flags */
227 #define LLE_EXCLUSIVE 0x2000 /* return lle xlocked */
228 #define LLE_UNLOCKED 0x4000 /* return lle unlocked */
229 #define LLE_ADDRONLY 0x4000 /* return lladdr instead of full header */
230 #define LLE_CREATE 0x8000 /* hint to avoid lle lookup */
231
232 /* LLE flags used by fastpath code */
233 #define RLLE_VALID 0x0001 /* entry is valid */
234 #define RLLE_IFADDR LLE_IFADDR /* entry is ifaddr */
235
236 #define LLATBL_HASH(key, mask) \
237 (((((((key >> 8) ^ key) >> 8) ^ key) >> 8) ^ key) & mask)
238
239 struct lltable *lltable_allocate_htbl(uint32_t hsize);
240 void lltable_purge(struct lltable *);
241 void lltable_free(struct lltable *);
242 void lltable_link(struct lltable *llt);
243 void lltable_prefix_free(int, struct sockaddr *,
244 struct sockaddr *, uint16_t);
245 #if 0
246 void lltable_drain(int);
247 #endif
248 int lltable_sysctl_dumparp(int, struct sysctl_req *);
249
250 size_t llentry_free(struct llentry *);
251 struct llentry *llentry_alloc(struct ifnet *, struct lltable *,
252 struct sockaddr_storage *);
253
254 /* helper functions */
255 size_t lltable_drop_entry_queue(struct llentry *);
256 void lltable_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
257 const char *ll_addr);
258 int lltable_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
259 const char *linkhdr, size_t linkhdrsize, int lladdr_off);
260
261 int lltable_calc_llheader(struct ifnet *ifp, int family, char *lladdr,
262 char *buf, size_t *bufsize, int *lladdr_off);
263 void lltable_update_ifaddr(struct lltable *llt);
264 struct llentry *lltable_alloc_entry(struct lltable *llt, uint16_t flags,
265 const struct sockaddr *l4addr);
266 void lltable_free_entry(struct lltable *llt, struct llentry *lle);
267 int lltable_delete_addr(struct lltable *llt, u_int flags,
268 const struct sockaddr *l3addr);
269 void lltable_link_entry(struct lltable *llt, struct llentry *lle);
270 void lltable_unlink_entry(struct lltable *llt, struct llentry *lle);
271 void lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa);
272 struct ifnet *lltable_get_ifp(const struct lltable *llt);
273 int lltable_get_af(const struct lltable *llt);
274
275 int lltable_foreach_lle(struct lltable *llt, llt_foreach_cb_t *f,
276 void *farg);
277 /*
278 * Generic link layer address lookup function.
279 */
280 static __inline struct llentry *
lla_lookup(struct lltable * llt,uint16_t flags,const struct sockaddr * l3addr)281 lla_lookup(struct lltable *llt, uint16_t flags, const struct sockaddr *l3addr)
282 {
283 return __unsafe_forge_single(struct llentry *, llt->llt_lookup(llt, flags, l3addr));
284 }
285
286 int lla_rt_output(struct rt_msghdr *, struct rt_addrinfo *);
287
288 enum {
289 LLENTRY_RESOLVED,
290 LLENTRY_TIMEDOUT,
291 LLENTRY_DELETED,
292 LLENTRY_EXPIRED,
293 };
294
295 typedef void (*lle_event_fn)(struct eventhandler_entry_arg, struct llentry *, int);
296 EVENTHANDLER_DECLARE(lle_event, lle_event_fn);
297 #endif /* _NET_IF_LLATBL_H_ */
298