1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2012 The FreeBSD Foundation
5 *
6 * This software was developed by Edward Tomasz Napierala under sponsorship
7 * from the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 */
31
32 /*
33 * iSCSI Common Layer. It's used by both the initiator and target to send
34 * and receive iSCSI PDUs.
35 */
36
37 #include <sys/cdefs.h>
38 #include <sys/param.h>
39 #include <sys/condvar.h>
40 #include <sys/conf.h>
41 #include <sys/lock.h>
42 #include <sys/kernel.h>
43 #include <sys/malloc.h>
44 #include <sys/mutex.h>
45 #include <sys/module.h>
46 #include <sys/queue.h>
47 #include <sys/sbuf.h>
48 #include <sys/socket.h>
49 #include <sys/sysctl.h>
50 #include <sys/systm.h>
51 #include <sys/sx.h>
52
53 #include <dev/iscsi/icl.h>
54 #include <icl_conn_if.h>
55
56 struct icl_module {
57 TAILQ_ENTRY(icl_module) im_next;
58 char *im_name;
59 bool im_iser;
60 int im_priority;
61 int (*im_limits)(struct icl_drv_limits *idl,
62 int socket);
63 struct icl_conn *(*im_new_conn)(const char *name,
64 struct mtx *lock);
65 };
66
67 struct icl_softc {
68 struct sx sc_lock;
69 TAILQ_HEAD(, icl_module) sc_modules;
70 };
71
72 static int sysctl_kern_icl_offloads(SYSCTL_HANDLER_ARGS);
73 static MALLOC_DEFINE(M_ICL, "icl", "iSCSI Common Layer");
74 static struct icl_softc *sc;
75
76 SYSCTL_NODE(_kern, OID_AUTO, icl, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
77 "iSCSI Common Layer");
78 int icl_debug = 1;
79 SYSCTL_INT(_kern_icl, OID_AUTO, debug, CTLFLAG_RWTUN,
80 &icl_debug, 0, "Enable debug messages");
81 SYSCTL_PROC(_kern_icl, OID_AUTO, offloads,
82 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
83 NULL, false, sysctl_kern_icl_offloads, "A",
84 "List of ICL modules");
85 SYSCTL_PROC(_kern_icl, OID_AUTO, iser_offloads,
86 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
87 NULL, true, sysctl_kern_icl_offloads, "A",
88 "List of iSER ICL modules");
89
90 static int
sysctl_kern_icl_offloads(SYSCTL_HANDLER_ARGS)91 sysctl_kern_icl_offloads(SYSCTL_HANDLER_ARGS)
92 {
93 const struct icl_module *im;
94 struct sbuf sb;
95 bool iser = arg2;
96 int error;
97
98 sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL);
99
100 sx_slock(&sc->sc_lock);
101 TAILQ_FOREACH(im, &sc->sc_modules, im_next) {
102 if (im->im_iser != iser)
103 continue;
104 if (im != TAILQ_FIRST(&sc->sc_modules))
105 sbuf_putc(&sb, ' ');
106 sbuf_printf(&sb, "%s", im->im_name);
107 }
108 sx_sunlock(&sc->sc_lock);
109
110 error = sbuf_finish(&sb);
111 if (error == 0)
112 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb));
113 sbuf_delete(&sb);
114 return (error);
115 }
116
117 static struct icl_module *
icl_find(const char * name,bool iser,bool quiet)118 icl_find(const char *name, bool iser, bool quiet)
119 {
120 struct icl_module *im, *im_max;
121
122 sx_assert(&sc->sc_lock, SA_LOCKED);
123
124 /*
125 * If the name was not specified, pick a module with highest
126 * priority.
127 */
128 if (name == NULL || name[0] == '\0') {
129 im_max = NULL;
130 TAILQ_FOREACH(im, &sc->sc_modules, im_next) {
131 if (im->im_iser != iser)
132 continue;
133 if (im_max == NULL ||
134 im->im_priority > im_max->im_priority)
135 im_max = im;
136 }
137
138 if (iser && im_max == NULL && !quiet)
139 ICL_WARN("no iSER-capable offload found");
140
141 return (im_max);
142 }
143
144 TAILQ_FOREACH(im, &sc->sc_modules, im_next) {
145 if (strcasecmp(im->im_name, name) != 0)
146 continue;
147
148 if (!im->im_iser && iser && !quiet) {
149 ICL_WARN("offload \"%s\" is not iSER-capable", name);
150 return (NULL);
151 }
152 if (im->im_iser && !iser && !quiet) {
153 ICL_WARN("offload \"%s\" is iSER-only", name);
154 return (NULL);
155 }
156
157 return (im);
158 }
159
160 if (!quiet)
161 ICL_WARN("offload \"%s\" not found", name);
162
163 return (NULL);
164 }
165
166 struct icl_conn *
icl_new_conn(const char * offload,bool iser,const char * name,struct mtx * lock)167 icl_new_conn(const char *offload, bool iser, const char *name, struct mtx *lock)
168 {
169 struct icl_module *im;
170 struct icl_conn *ic;
171
172 sx_slock(&sc->sc_lock);
173 im = icl_find(offload, iser, false);
174 if (im == NULL) {
175 sx_sunlock(&sc->sc_lock);
176 return (NULL);
177 }
178
179 ic = im->im_new_conn(name, lock);
180 sx_sunlock(&sc->sc_lock);
181
182 return (ic);
183 }
184
185 int
icl_limits(const char * offload,bool iser,int socket,struct icl_drv_limits * idl)186 icl_limits(const char *offload, bool iser, int socket,
187 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, socket);
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 *,int),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 *, int),
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