FreeBSD/Linux Kernel Cross Reference
sys/rpc/replay.c
1 /*-
2 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
3 * Authors: Doug Rabson <dfr@rabson.org>
4 * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
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 __FBSDID("$FreeBSD: releng/8.3/sys/rpc/replay.c 212310 2010-09-08 01:41:22Z rmacklem $");
30
31 #include <sys/param.h>
32 #include <sys/hash.h>
33 #include <sys/kernel.h>
34 #include <sys/lock.h>
35 #include <sys/mbuf.h>
36 #include <sys/mutex.h>
37 #include <sys/queue.h>
38
39 #include <rpc/rpc.h>
40 #include <rpc/replay.h>
41
42 struct replay_cache_entry {
43 int rce_hash;
44 struct rpc_msg rce_msg;
45 struct sockaddr_storage rce_addr;
46 struct rpc_msg rce_repmsg;
47 struct mbuf *rce_repbody;
48
49 TAILQ_ENTRY(replay_cache_entry) rce_link;
50 TAILQ_ENTRY(replay_cache_entry) rce_alllink;
51 };
52 TAILQ_HEAD(replay_cache_list, replay_cache_entry);
53
54 static struct replay_cache_entry *
55 replay_alloc(struct replay_cache *rc, struct rpc_msg *msg,
56 struct sockaddr *addr, int h);
57 static void replay_free(struct replay_cache *rc,
58 struct replay_cache_entry *rce);
59 static void replay_prune(struct replay_cache *rc);
60
61 #define REPLAY_HASH_SIZE 256
62 #define REPLAY_MAX 1024
63
64 struct replay_cache {
65 struct replay_cache_list rc_cache[REPLAY_HASH_SIZE];
66 struct replay_cache_list rc_all;
67 struct mtx rc_lock;
68 int rc_count;
69 size_t rc_size;
70 size_t rc_maxsize;
71 };
72
73 struct replay_cache *
74 replay_newcache(size_t maxsize)
75 {
76 struct replay_cache *rc;
77 int i;
78
79 rc = malloc(sizeof(*rc), M_RPC, M_WAITOK|M_ZERO);
80 for (i = 0; i < REPLAY_HASH_SIZE; i++)
81 TAILQ_INIT(&rc->rc_cache[i]);
82 TAILQ_INIT(&rc->rc_all);
83 mtx_init(&rc->rc_lock, "rc_lock", NULL, MTX_DEF);
84 rc->rc_maxsize = maxsize;
85
86 return (rc);
87 }
88
89 void
90 replay_setsize(struct replay_cache *rc, size_t newmaxsize)
91 {
92
93 mtx_lock(&rc->rc_lock);
94 rc->rc_maxsize = newmaxsize;
95 replay_prune(rc);
96 mtx_unlock(&rc->rc_lock);
97 }
98
99 void
100 replay_freecache(struct replay_cache *rc)
101 {
102
103 mtx_lock(&rc->rc_lock);
104 while (TAILQ_FIRST(&rc->rc_all))
105 replay_free(rc, TAILQ_FIRST(&rc->rc_all));
106 mtx_destroy(&rc->rc_lock);
107 free(rc, M_RPC);
108 }
109
110 static struct replay_cache_entry *
111 replay_alloc(struct replay_cache *rc,
112 struct rpc_msg *msg, struct sockaddr *addr, int h)
113 {
114 struct replay_cache_entry *rce;
115
116 rc->rc_count++;
117 rce = malloc(sizeof(*rce), M_RPC, M_NOWAIT|M_ZERO);
118 rce->rce_hash = h;
119 rce->rce_msg = *msg;
120 bcopy(addr, &rce->rce_addr, addr->sa_len);
121
122 TAILQ_INSERT_HEAD(&rc->rc_cache[h], rce, rce_link);
123 TAILQ_INSERT_HEAD(&rc->rc_all, rce, rce_alllink);
124
125 return (rce);
126 }
127
128 static void
129 replay_free(struct replay_cache *rc, struct replay_cache_entry *rce)
130 {
131
132 rc->rc_count--;
133 TAILQ_REMOVE(&rc->rc_cache[rce->rce_hash], rce, rce_link);
134 TAILQ_REMOVE(&rc->rc_all, rce, rce_alllink);
135 if (rce->rce_repbody) {
136 rc->rc_size -= m_length(rce->rce_repbody, NULL);
137 m_freem(rce->rce_repbody);
138 }
139 free(rce, M_RPC);
140 }
141
142 static void
143 replay_prune(struct replay_cache *rc)
144 {
145 struct replay_cache_entry *rce;
146 bool_t freed_one;
147
148 if (rc->rc_count >= REPLAY_MAX || rc->rc_size > rc->rc_maxsize) {
149 do {
150 freed_one = FALSE;
151 /*
152 * Try to free an entry. Don't free in-progress entries
153 */
154 TAILQ_FOREACH_REVERSE(rce, &rc->rc_all,
155 replay_cache_list, rce_alllink) {
156 if (rce->rce_repmsg.rm_xid) {
157 replay_free(rc, rce);
158 freed_one = TRUE;
159 break;
160 }
161 }
162 } while (freed_one
163 && (rc->rc_count >= REPLAY_MAX
164 || rc->rc_size > rc->rc_maxsize));
165 }
166 }
167
168 enum replay_state
169 replay_find(struct replay_cache *rc, struct rpc_msg *msg,
170 struct sockaddr *addr, struct rpc_msg *repmsg, struct mbuf **mp)
171 {
172 int h = HASHSTEP(HASHINIT, msg->rm_xid) % REPLAY_HASH_SIZE;
173 struct replay_cache_entry *rce;
174
175 mtx_lock(&rc->rc_lock);
176 TAILQ_FOREACH(rce, &rc->rc_cache[h], rce_link) {
177 if (rce->rce_msg.rm_xid == msg->rm_xid
178 && rce->rce_msg.rm_call.cb_prog == msg->rm_call.cb_prog
179 && rce->rce_msg.rm_call.cb_vers == msg->rm_call.cb_vers
180 && rce->rce_msg.rm_call.cb_proc == msg->rm_call.cb_proc
181 && rce->rce_addr.ss_len == addr->sa_len
182 && bcmp(&rce->rce_addr, addr, addr->sa_len) == 0) {
183 if (rce->rce_repmsg.rm_xid) {
184 /*
185 * We have a reply for this
186 * message. Copy it and return. Keep
187 * replay_all LRU sorted
188 */
189 TAILQ_REMOVE(&rc->rc_all, rce, rce_alllink);
190 TAILQ_INSERT_HEAD(&rc->rc_all, rce,
191 rce_alllink);
192 *repmsg = rce->rce_repmsg;
193 if (rce->rce_repbody) {
194 *mp = m_copym(rce->rce_repbody,
195 0, M_COPYALL, M_NOWAIT);
196 mtx_unlock(&rc->rc_lock);
197 if (!*mp)
198 return (RS_ERROR);
199 } else {
200 mtx_unlock(&rc->rc_lock);
201 }
202 return (RS_DONE);
203 } else {
204 mtx_unlock(&rc->rc_lock);
205 return (RS_INPROGRESS);
206 }
207 }
208 }
209
210 replay_prune(rc);
211
212 rce = replay_alloc(rc, msg, addr, h);
213
214 mtx_unlock(&rc->rc_lock);
215
216 if (!rce)
217 return (RS_ERROR);
218 else
219 return (RS_NEW);
220 }
221
222 void
223 replay_setreply(struct replay_cache *rc,
224 struct rpc_msg *repmsg, struct sockaddr *addr, struct mbuf *m)
225 {
226 int h = HASHSTEP(HASHINIT, repmsg->rm_xid) % REPLAY_HASH_SIZE;
227 struct replay_cache_entry *rce;
228
229 /*
230 * Copy the reply before the lock so we can sleep.
231 */
232 if (m)
233 m = m_copym(m, 0, M_COPYALL, M_WAITOK);
234
235 mtx_lock(&rc->rc_lock);
236 TAILQ_FOREACH(rce, &rc->rc_cache[h], rce_link) {
237 if (rce->rce_msg.rm_xid == repmsg->rm_xid
238 && rce->rce_addr.ss_len == addr->sa_len
239 && bcmp(&rce->rce_addr, addr, addr->sa_len) == 0) {
240 break;
241 }
242 }
243 if (rce) {
244 rce->rce_repmsg = *repmsg;
245 rce->rce_repbody = m;
246 if (m)
247 rc->rc_size += m_length(m, NULL);
248 }
249 mtx_unlock(&rc->rc_lock);
250 }
Cache object: b311eefa766ccdba642727cbdb9f0166
|