FreeBSD/Linux Kernel Cross Reference
sys/rpc/replay.c
1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
5 * Authors: Doug Rabson <dfr@rabson.org>
6 * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <sys/param.h>
34 #include <sys/hash.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/mbuf.h>
39 #include <sys/mutex.h>
40 #include <sys/queue.h>
41
42 #include <rpc/rpc.h>
43 #include <rpc/replay.h>
44
45 struct replay_cache_entry {
46 int rce_hash;
47 struct rpc_msg rce_msg;
48 struct sockaddr_storage rce_addr;
49 struct rpc_msg rce_repmsg;
50 struct mbuf *rce_repbody;
51
52 TAILQ_ENTRY(replay_cache_entry) rce_link;
53 TAILQ_ENTRY(replay_cache_entry) rce_alllink;
54 };
55 TAILQ_HEAD(replay_cache_list, replay_cache_entry);
56
57 static struct replay_cache_entry *
58 replay_alloc(struct replay_cache *rc, struct rpc_msg *msg,
59 struct sockaddr *addr, int h);
60 static void replay_free(struct replay_cache *rc,
61 struct replay_cache_entry *rce);
62 static void replay_prune(struct replay_cache *rc);
63
64 #define REPLAY_HASH_SIZE 256
65 #define REPLAY_MAX 1024
66
67 struct replay_cache {
68 struct replay_cache_list rc_cache[REPLAY_HASH_SIZE];
69 struct replay_cache_list rc_all;
70 struct mtx rc_lock;
71 int rc_count;
72 size_t rc_size;
73 size_t rc_maxsize;
74 };
75
76 struct replay_cache *
77 replay_newcache(size_t maxsize)
78 {
79 struct replay_cache *rc;
80 int i;
81
82 rc = malloc(sizeof(*rc), M_RPC, M_WAITOK|M_ZERO);
83 for (i = 0; i < REPLAY_HASH_SIZE; i++)
84 TAILQ_INIT(&rc->rc_cache[i]);
85 TAILQ_INIT(&rc->rc_all);
86 mtx_init(&rc->rc_lock, "rc_lock", NULL, MTX_DEF);
87 rc->rc_maxsize = maxsize;
88
89 return (rc);
90 }
91
92 void
93 replay_setsize(struct replay_cache *rc, size_t newmaxsize)
94 {
95
96 mtx_lock(&rc->rc_lock);
97 rc->rc_maxsize = newmaxsize;
98 replay_prune(rc);
99 mtx_unlock(&rc->rc_lock);
100 }
101
102 void
103 replay_freecache(struct replay_cache *rc)
104 {
105
106 mtx_lock(&rc->rc_lock);
107 while (TAILQ_FIRST(&rc->rc_all))
108 replay_free(rc, TAILQ_FIRST(&rc->rc_all));
109 mtx_destroy(&rc->rc_lock);
110 free(rc, M_RPC);
111 }
112
113 static struct replay_cache_entry *
114 replay_alloc(struct replay_cache *rc,
115 struct rpc_msg *msg, struct sockaddr *addr, int h)
116 {
117 struct replay_cache_entry *rce;
118
119 mtx_assert(&rc->rc_lock, MA_OWNED);
120
121 rc->rc_count++;
122 rce = malloc(sizeof(*rce), M_RPC, M_NOWAIT|M_ZERO);
123 if (!rce)
124 return (NULL);
125 rce->rce_hash = h;
126 rce->rce_msg = *msg;
127 bcopy(addr, &rce->rce_addr, addr->sa_len);
128
129 TAILQ_INSERT_HEAD(&rc->rc_cache[h], rce, rce_link);
130 TAILQ_INSERT_HEAD(&rc->rc_all, rce, rce_alllink);
131
132 return (rce);
133 }
134
135 static void
136 replay_free(struct replay_cache *rc, struct replay_cache_entry *rce)
137 {
138
139 mtx_assert(&rc->rc_lock, MA_OWNED);
140
141 rc->rc_count--;
142 TAILQ_REMOVE(&rc->rc_cache[rce->rce_hash], rce, rce_link);
143 TAILQ_REMOVE(&rc->rc_all, rce, rce_alllink);
144 if (rce->rce_repbody) {
145 rc->rc_size -= m_length(rce->rce_repbody, NULL);
146 m_freem(rce->rce_repbody);
147 }
148 free(rce, M_RPC);
149 }
150
151 static void
152 replay_prune(struct replay_cache *rc)
153 {
154 struct replay_cache_entry *rce;
155
156 mtx_assert(&rc->rc_lock, MA_OWNED);
157
158 if (rc->rc_count < REPLAY_MAX && rc->rc_size <= rc->rc_maxsize)
159 return;
160
161 do {
162 /*
163 * Try to free an entry. Don't free in-progress entries.
164 */
165 TAILQ_FOREACH_REVERSE(rce, &rc->rc_all, replay_cache_list,
166 rce_alllink) {
167 if (rce->rce_repmsg.rm_xid)
168 break;
169 }
170 if (rce)
171 replay_free(rc, rce);
172 } while (rce && (rc->rc_count >= REPLAY_MAX
173 || rc->rc_size > rc->rc_maxsize));
174 }
175
176 enum replay_state
177 replay_find(struct replay_cache *rc, struct rpc_msg *msg,
178 struct sockaddr *addr, struct rpc_msg *repmsg, struct mbuf **mp)
179 {
180 int h = HASHSTEP(HASHINIT, msg->rm_xid) % REPLAY_HASH_SIZE;
181 struct replay_cache_entry *rce;
182
183 mtx_lock(&rc->rc_lock);
184 TAILQ_FOREACH(rce, &rc->rc_cache[h], rce_link) {
185 if (rce->rce_msg.rm_xid == msg->rm_xid
186 && rce->rce_msg.rm_call.cb_prog == msg->rm_call.cb_prog
187 && rce->rce_msg.rm_call.cb_vers == msg->rm_call.cb_vers
188 && rce->rce_msg.rm_call.cb_proc == msg->rm_call.cb_proc
189 && rce->rce_addr.ss_len == addr->sa_len
190 && bcmp(&rce->rce_addr, addr, addr->sa_len) == 0) {
191 if (rce->rce_repmsg.rm_xid) {
192 /*
193 * We have a reply for this
194 * message. Copy it and return. Keep
195 * replay_all LRU sorted
196 */
197 TAILQ_REMOVE(&rc->rc_all, rce, rce_alllink);
198 TAILQ_INSERT_HEAD(&rc->rc_all, rce,
199 rce_alllink);
200 *repmsg = rce->rce_repmsg;
201 if (rce->rce_repbody) {
202 *mp = m_copym(rce->rce_repbody,
203 0, M_COPYALL, M_NOWAIT);
204 mtx_unlock(&rc->rc_lock);
205 if (!*mp)
206 return (RS_ERROR);
207 } else {
208 mtx_unlock(&rc->rc_lock);
209 }
210 return (RS_DONE);
211 } else {
212 mtx_unlock(&rc->rc_lock);
213 return (RS_INPROGRESS);
214 }
215 }
216 }
217
218 replay_prune(rc);
219
220 rce = replay_alloc(rc, msg, addr, h);
221
222 mtx_unlock(&rc->rc_lock);
223
224 if (!rce)
225 return (RS_ERROR);
226 else
227 return (RS_NEW);
228 }
229
230 void
231 replay_setreply(struct replay_cache *rc,
232 struct rpc_msg *repmsg, struct sockaddr *addr, struct mbuf *m)
233 {
234 int h = HASHSTEP(HASHINIT, repmsg->rm_xid) % REPLAY_HASH_SIZE;
235 struct replay_cache_entry *rce;
236
237 /*
238 * Copy the reply before the lock so we can sleep.
239 */
240 if (m)
241 m = m_copym(m, 0, M_COPYALL, M_WAITOK);
242
243 mtx_lock(&rc->rc_lock);
244 TAILQ_FOREACH(rce, &rc->rc_cache[h], rce_link) {
245 if (rce->rce_msg.rm_xid == repmsg->rm_xid
246 && rce->rce_addr.ss_len == addr->sa_len
247 && bcmp(&rce->rce_addr, addr, addr->sa_len) == 0) {
248 break;
249 }
250 }
251 if (rce) {
252 rce->rce_repmsg = *repmsg;
253 rce->rce_repbody = m;
254 if (m)
255 rc->rc_size += m_length(m, NULL);
256 }
257 mtx_unlock(&rc->rc_lock);
258 }
Cache object: e3e46dae159d93ae470bd53456289d6e
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