1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2012 The FreeBSD Foundation
5 * All rights reserved.
6 *
7 * This software was developed by Edward Tomasz Napierala under sponsorship
8 * from the FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 */
32
33 /*
34 * iSCSI Common Layer. It's used by both the initiator and target to send
35 * and receive iSCSI PDUs.
36 */
37
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40
41 #include <sys/param.h>
42 #include <sys/condvar.h>
43 #include <sys/conf.h>
44 #include <sys/lock.h>
45 #include <sys/kernel.h>
46 #include <sys/malloc.h>
47 #include <sys/mutex.h>
48 #include <sys/module.h>
49 #include <sys/queue.h>
50 #include <sys/sbuf.h>
51 #include <sys/socket.h>
52 #include <sys/sysctl.h>
53 #include <sys/systm.h>
54 #include <sys/sx.h>
55
56 #include <dev/iscsi/icl.h>
57 #include <icl_conn_if.h>
58
59 struct icl_module {
60 TAILQ_ENTRY(icl_module) im_next;
61 char *im_name;
62 bool im_iser;
63 int im_priority;
64 int (*im_limits)(struct icl_drv_limits *idl);
65 struct icl_conn *(*im_new_conn)(const char *name,
66 struct mtx *lock);
67 };
68
69 struct icl_softc {
70 struct sx sc_lock;
71 TAILQ_HEAD(, icl_module) sc_modules;
72 };
73
74 static int sysctl_kern_icl_offloads(SYSCTL_HANDLER_ARGS);
75 static MALLOC_DEFINE(M_ICL, "icl", "iSCSI Common Layer");
76 static struct icl_softc *sc;
77
78 SYSCTL_NODE(_kern, OID_AUTO, icl, CTLFLAG_RD, 0, "iSCSI Common Layer");
79 int icl_debug = 1;
80 SYSCTL_INT(_kern_icl, OID_AUTO, debug, CTLFLAG_RWTUN,
81 &icl_debug, 0, "Enable debug messages");
82 SYSCTL_PROC(_kern_icl, OID_AUTO, offloads,
83 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
84 NULL, false, sysctl_kern_icl_offloads, "A",
85 "List of ICL modules");
86 SYSCTL_PROC(_kern_icl, OID_AUTO, iser_offloads,
87 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
88 NULL, true, sysctl_kern_icl_offloads, "A",
89 "List of iSER ICL modules");
90
91 static int
sysctl_kern_icl_offloads(SYSCTL_HANDLER_ARGS)92 sysctl_kern_icl_offloads(SYSCTL_HANDLER_ARGS)
93 {
94 const struct icl_module *im;
95 struct sbuf sb;
96 bool iser = arg2;
97 int error;
98
99 sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL);
100
101 sx_slock(&sc->sc_lock);
102 TAILQ_FOREACH(im, &sc->sc_modules, im_next) {
103 if (im->im_iser != iser)
104 continue;
105 if (im != TAILQ_FIRST(&sc->sc_modules))
106 sbuf_putc(&sb, ' ');
107 sbuf_printf(&sb, "%s", im->im_name);
108 }
109 sx_sunlock(&sc->sc_lock);
110
111 error = sbuf_finish(&sb);
112 if (error == 0)
113 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb));
114 sbuf_delete(&sb);
115 return (error);
116 }
117
118 static struct icl_module *
icl_find(const char * name,bool iser,bool quiet)119 icl_find(const char *name, bool iser, bool quiet)
120 {
121 struct icl_module *im, *im_max;
122
123 sx_assert(&sc->sc_lock, SA_LOCKED);
124
125 /*
126 * If the name was not specified, pick a module with highest
127 * priority.
128 */
129 if (name == NULL || name[0] == '\0') {
130 im_max = NULL;
131 TAILQ_FOREACH(im, &sc->sc_modules, im_next) {
132 if (im->im_iser != iser)
133 continue;
134 if (im_max == NULL ||
135 im->im_priority > im_max->im_priority)
136 im_max = im;
137 }
138
139 if (iser && im_max == NULL && !quiet)
140 ICL_WARN("no iSER-capable offload found");
141
142 return (im_max);
143 }
144
145 TAILQ_FOREACH(im, &sc->sc_modules, im_next) {
146 if (strcasecmp(im->im_name, name) != 0)
147 continue;
148
149 if (!im->im_iser && iser && !quiet) {
150 ICL_WARN("offload \"%s\" is not iSER-capable", name);
151 return (NULL);
152 }
153 if (im->im_iser && !iser && !quiet) {
154 ICL_WARN("offload \"%s\" is iSER-only", name);
155 return (NULL);
156 }
157
158 return (im);
159 }
160
161 if (!quiet)
162 ICL_WARN("offload \"%s\" not found", name);
163
164 return (NULL);
165 }
166
167 struct icl_conn *
icl_new_conn(const char * offload,bool iser,const char * name,struct mtx * lock)168 icl_new_conn(const char *offload, bool iser, const char *name, struct mtx *lock)
169 {
170 struct icl_module *im;
171 struct icl_conn *ic;
172
173 sx_slock(&sc->sc_lock);
174 im = icl_find(offload, iser, false);
175 if (im == NULL) {
176 sx_sunlock(&sc->sc_lock);
177 return (NULL);
178 }
179
180 ic = im->im_new_conn(name, lock);
181 sx_sunlock(&sc->sc_lock);
182
183 return (ic);
184 }
185
186 int
icl_limits(const char * offload,bool iser,struct icl_drv_limits * idl)187 icl_limits(const char *offload, bool iser, struct icl_drv_limits *idl)
188 {
189 struct icl_module *im;
190 int error;
191
192 bzero(idl, sizeof(*idl));
193 sx_slock(&sc->sc_lock);
194 im = icl_find(offload, iser, false);
195 if (im == NULL) {
196 sx_sunlock(&sc->sc_lock);
197 return (ENXIO);
198 }
199
200 error = im->im_limits(idl);
201 sx_sunlock(&sc->sc_lock);
202
203 /*
204 * Validate the limits provided by the driver against values allowed by
205 * the iSCSI RFC. 0 means iscsid/ctld should pick a reasonable value.
206 *
207 * Note that max_send_dsl is an internal implementation detail and not
208 * part of the RFC.
209 */
210 #define OUT_OF_RANGE(x, lo, hi) ((x) != 0 && ((x) < (lo) || (x) > (hi)))
211 if (error == 0 &&
212 (OUT_OF_RANGE(idl->idl_max_recv_data_segment_length, 512, 16777215) ||
213 OUT_OF_RANGE(idl->idl_max_send_data_segment_length, 512, 16777215) ||
214 OUT_OF_RANGE(idl->idl_max_burst_length, 512, 16777215) ||
215 OUT_OF_RANGE(idl->idl_first_burst_length, 512, 16777215))) {
216 error = EINVAL;
217 }
218 #undef OUT_OF_RANGE
219
220 /*
221 * If both first_burst and max_burst are provided then first_burst must
222 * not exceed max_burst.
223 */
224 if (error == 0 && idl->idl_first_burst_length > 0 &&
225 idl->idl_max_burst_length > 0 &&
226 idl->idl_first_burst_length > idl->idl_max_burst_length) {
227 error = EINVAL;
228 }
229
230 return (error);
231 }
232
233 int
icl_register(const char * offload,bool iser,int priority,int (* limits)(struct icl_drv_limits *),struct icl_conn * (* new_conn)(const char *,struct mtx *))234 icl_register(const char *offload, bool iser, int priority,
235 int (*limits)(struct icl_drv_limits *),
236 struct icl_conn *(*new_conn)(const char *, struct mtx *))
237 {
238 struct icl_module *im;
239
240 sx_xlock(&sc->sc_lock);
241 im = icl_find(offload, iser, true);
242 if (im != NULL) {
243 ICL_WARN("offload \"%s\" already registered", offload);
244 sx_xunlock(&sc->sc_lock);
245 return (EBUSY);
246 }
247
248 im = malloc(sizeof(*im), M_ICL, M_ZERO | M_WAITOK);
249 im->im_name = strdup(offload, M_ICL);
250 im->im_iser = iser;
251 im->im_priority = priority;
252 im->im_limits = limits;
253 im->im_new_conn = new_conn;
254
255 TAILQ_INSERT_HEAD(&sc->sc_modules, im, im_next);
256 sx_xunlock(&sc->sc_lock);
257
258 ICL_DEBUG("offload \"%s\" registered", offload);
259 return (0);
260 }
261
262 int
icl_unregister(const char * offload,bool rdma)263 icl_unregister(const char *offload, bool rdma)
264 {
265 struct icl_module *im;
266
267 sx_xlock(&sc->sc_lock);
268 im = icl_find(offload, rdma, true);
269 if (im == NULL) {
270 ICL_WARN("offload \"%s\" not registered", offload);
271 sx_xunlock(&sc->sc_lock);
272 return (ENXIO);
273 }
274
275 TAILQ_REMOVE(&sc->sc_modules, im, im_next);
276 sx_xunlock(&sc->sc_lock);
277
278 free(im->im_name, M_ICL);
279 free(im, M_ICL);
280
281 ICL_DEBUG("offload \"%s\" unregistered", offload);
282 return (0);
283 }
284
285 static int
icl_load(void)286 icl_load(void)
287 {
288
289 sc = malloc(sizeof(*sc), M_ICL, M_ZERO | M_WAITOK);
290 sx_init(&sc->sc_lock, "icl");
291 TAILQ_INIT(&sc->sc_modules);
292
293 return (0);
294 }
295
296 static int
icl_unload(void)297 icl_unload(void)
298 {
299
300 sx_slock(&sc->sc_lock);
301 KASSERT(TAILQ_EMPTY(&sc->sc_modules), ("still have modules"));
302 sx_sunlock(&sc->sc_lock);
303
304 sx_destroy(&sc->sc_lock);
305 free(sc, M_ICL);
306
307 return (0);
308 }
309
310 static int
icl_modevent(module_t mod,int what,void * arg)311 icl_modevent(module_t mod, int what, void *arg)
312 {
313
314 switch (what) {
315 case MOD_LOAD:
316 return (icl_load());
317 case MOD_UNLOAD:
318 return (icl_unload());
319 default:
320 return (EINVAL);
321 }
322 }
323
324 moduledata_t icl_data = {
325 "icl",
326 icl_modevent,
327 0
328 };
329
330 DECLARE_MODULE(icl, icl_data, SI_SUB_DRIVERS, SI_ORDER_FIRST);
331 MODULE_VERSION(icl, 1);
332