1 /*-
2 * Copyright (c) 2012 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by Edward Tomasz Napierala under sponsorship
6 * from the FreeBSD Foundation.
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
31 /*
32 * iSCSI Common Layer. It's used by both the initiator and target to send
33 * and receive iSCSI PDUs.
34 */
35
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38
39 #include <sys/param.h>
40 #include <sys/condvar.h>
41 #include <sys/conf.h>
42 #include <sys/lock.h>
43 #include <sys/kernel.h>
44 #include <sys/malloc.h>
45 #include <sys/mutex.h>
46 #include <sys/module.h>
47 #include <sys/queue.h>
48 #include <sys/sysctl.h>
49 #include <sys/systm.h>
50 #include <sys/sx.h>
51
52 #include <dev/iscsi/icl.h>
53 #include <icl_conn_if.h>
54
55 struct icl_module {
56 TAILQ_ENTRY(icl_module) im_next;
57 char *im_name;
58 int im_priority;
59 int (*im_limits)(size_t *limitp);
60 struct icl_conn *(*im_new_conn)(const char *name,
61 struct mtx *lock);
62 };
63
64 struct icl_softc {
65 struct sx sc_lock;
66 TAILQ_HEAD(, icl_module) sc_modules;
67 };
68
69 SYSCTL_NODE(_kern, OID_AUTO, icl, CTLFLAG_RD, 0, "iSCSI Common Layer");
70 int icl_debug = 1;
71 SYSCTL_INT(_kern_icl, OID_AUTO, debug, CTLFLAG_RWTUN,
72 &icl_debug, 0, "Enable debug messages");
73
74 static MALLOC_DEFINE(M_ICL, "icl", "iSCSI Common Layer");
75 static struct icl_softc *sc;
76
77 static struct icl_module *
icl_find(const char * name)78 icl_find(const char *name)
79 {
80 struct icl_module *im, *im_max;
81
82 sx_assert(&sc->sc_lock, SA_LOCKED);
83
84 /*
85 * If the name was not specified, pick a module with highest
86 * priority.
87 */
88 if (name == NULL || name[0] == '\0') {
89 im_max = TAILQ_FIRST(&sc->sc_modules);
90 TAILQ_FOREACH(im, &sc->sc_modules, im_next) {
91 if (im->im_priority > im_max->im_priority)
92 im_max = im;
93 }
94
95 return (im_max);
96 }
97
98 TAILQ_FOREACH(im, &sc->sc_modules, im_next) {
99 if (strcasecmp(im->im_name, name) == 0)
100 return (im);
101 }
102
103 return (NULL);
104 }
105
106 struct icl_conn *
icl_new_conn(const char * offload,const char * name,struct mtx * lock)107 icl_new_conn(const char *offload, const char *name, struct mtx *lock)
108 {
109 struct icl_module *im;
110 struct icl_conn *ic;
111
112 sx_slock(&sc->sc_lock);
113 im = icl_find(offload);
114
115 if (im == NULL) {
116 ICL_WARN("offload \"%s\" not found", offload);
117 sx_sunlock(&sc->sc_lock);
118 return (NULL);
119 }
120
121 ic = im->im_new_conn(name, lock);
122 sx_sunlock(&sc->sc_lock);
123
124 return (ic);
125 }
126
127 int
icl_limits(const char * offload,size_t * limitp)128 icl_limits(const char *offload, size_t *limitp)
129 {
130 struct icl_module *im;
131 int error;
132
133 sx_slock(&sc->sc_lock);
134 im = icl_find(offload);
135
136 if (im == NULL) {
137 ICL_WARN("offload \"%s\" not found", offload);
138 sx_sunlock(&sc->sc_lock);
139 return (ENXIO);
140 }
141
142 error = im->im_limits(limitp);
143 sx_sunlock(&sc->sc_lock);
144
145 return (error);
146 }
147
148
149 int
icl_register(const char * offload,int priority,int (* limits)(size_t *),struct icl_conn * (* new_conn)(const char *,struct mtx *))150 icl_register(const char *offload, int priority, int (*limits)(size_t *),
151 struct icl_conn *(*new_conn)(const char *, struct mtx *))
152 {
153 struct icl_module *im;
154
155 sx_xlock(&sc->sc_lock);
156 im = icl_find(offload);
157
158 if (im != NULL) {
159 ICL_WARN("offload \"%s\" already registered", offload);
160 sx_xunlock(&sc->sc_lock);
161 return (EBUSY);
162 }
163
164 im = malloc(sizeof(*im), M_ICL, M_ZERO | M_WAITOK);
165 im->im_name = strdup(offload, M_ICL);
166 im->im_priority = priority;
167 im->im_limits = limits;
168 im->im_new_conn = new_conn;
169
170 TAILQ_INSERT_HEAD(&sc->sc_modules, im, im_next);
171 sx_xunlock(&sc->sc_lock);
172
173 ICL_DEBUG("offload \"%s\" registered", offload);
174 return (0);
175 }
176
177 int
icl_unregister(const char * offload)178 icl_unregister(const char *offload)
179 {
180 struct icl_module *im;
181
182 sx_xlock(&sc->sc_lock);
183 im = icl_find(offload);
184
185 if (im == NULL) {
186 ICL_WARN("offload \"%s\" not registered", offload);
187 sx_xunlock(&sc->sc_lock);
188 return (ENXIO);
189 }
190
191 TAILQ_REMOVE(&sc->sc_modules, im, im_next);
192 sx_xunlock(&sc->sc_lock);
193
194 free(im->im_name, M_ICL);
195 free(im, M_ICL);
196
197 ICL_DEBUG("offload \"%s\" unregistered", offload);
198 return (0);
199 }
200
201 static int
icl_load(void)202 icl_load(void)
203 {
204
205 sc = malloc(sizeof(*sc), M_ICL, M_ZERO | M_WAITOK);
206 sx_init(&sc->sc_lock, "icl");
207 TAILQ_INIT(&sc->sc_modules);
208
209 return (0);
210 }
211
212 static int
icl_unload(void)213 icl_unload(void)
214 {
215
216 sx_slock(&sc->sc_lock);
217 KASSERT(TAILQ_EMPTY(&sc->sc_modules), ("still have modules"));
218 sx_sunlock(&sc->sc_lock);
219
220 sx_destroy(&sc->sc_lock);
221 free(sc, M_ICL);
222
223 return (0);
224 }
225
226 static int
icl_modevent(module_t mod,int what,void * arg)227 icl_modevent(module_t mod, int what, void *arg)
228 {
229
230 switch (what) {
231 case MOD_LOAD:
232 return (icl_load());
233 case MOD_UNLOAD:
234 return (icl_unload());
235 default:
236 return (EINVAL);
237 }
238 }
239
240 moduledata_t icl_data = {
241 "icl",
242 icl_modevent,
243 0
244 };
245
246 DECLARE_MODULE(icl, icl_data, SI_SUB_DRIVERS, SI_ORDER_FIRST);
247 MODULE_VERSION(icl, 1);
248