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/param.h>
38 #include <sys/condvar.h>
39 #include <sys/conf.h>
40 #include <sys/lock.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/mutex.h>
44 #include <sys/module.h>
45 #include <sys/queue.h>
46 #include <sys/sbuf.h>
47 #include <sys/socket.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 bool im_iser;
59 int im_priority;
60 int (*im_limits)(struct icl_drv_limits *idl,
61 int socket);
62 struct icl_conn *(*im_new_conn)(const char *name,
63 struct mtx *lock);
64 };
65
66 struct icl_softc {
67 struct sx sc_lock;
68 TAILQ_HEAD(, icl_module) sc_modules;
69 };
70
71 static int sysctl_kern_icl_offloads(SYSCTL_HANDLER_ARGS);
72 static MALLOC_DEFINE(M_ICL, "icl", "iSCSI Common Layer");
73 static struct icl_softc *sc;
74
75 SYSCTL_NODE(_kern, OID_AUTO, icl, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
76 "iSCSI Common Layer");
77 int icl_debug = 1;
78 SYSCTL_INT(_kern_icl, OID_AUTO, debug, CTLFLAG_RWTUN,
79 &icl_debug, 0, "Enable debug messages");
80 SYSCTL_PROC(_kern_icl, OID_AUTO, offloads,
81 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
82 NULL, false, sysctl_kern_icl_offloads, "A",
83 "List of ICL modules");
84 SYSCTL_PROC(_kern_icl, OID_AUTO, iser_offloads,
85 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
86 NULL, true, sysctl_kern_icl_offloads, "A",
87 "List of iSER ICL modules");
88
89 static int
sysctl_kern_icl_offloads(SYSCTL_HANDLER_ARGS)90 sysctl_kern_icl_offloads(SYSCTL_HANDLER_ARGS)
91 {
92 const struct icl_module *im;
93 struct sbuf sb;
94 bool iser = arg2;
95 int error;
96
97 sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL);
98
99 sx_slock(&sc->sc_lock);
100 TAILQ_FOREACH(im, &sc->sc_modules, im_next) {
101 if (im->im_iser != iser)
102 continue;
103 if (im != TAILQ_FIRST(&sc->sc_modules))
104 sbuf_putc(&sb, ' ');
105 sbuf_printf(&sb, "%s", im->im_name);
106 }
107 sx_sunlock(&sc->sc_lock);
108
109 error = sbuf_finish(&sb);
110 if (error == 0)
111 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb));
112 sbuf_delete(&sb);
113 return (error);
114 }
115
116 static struct icl_module *
icl_find(const char * name,bool iser,bool quiet)117 icl_find(const char *name, bool iser, bool quiet)
118 {
119 struct icl_module *im, *im_max;
120
121 sx_assert(&sc->sc_lock, SA_LOCKED);
122
123 /*
124 * If the name was not specified, pick a module with highest
125 * priority.
126 */
127 if (name == NULL || name[0] == '\0') {
128 im_max = NULL;
129 TAILQ_FOREACH(im, &sc->sc_modules, im_next) {
130 if (im->im_iser != iser)
131 continue;
132 if (im_max == NULL ||
133 im->im_priority > im_max->im_priority)
134 im_max = im;
135 }
136
137 if (iser && im_max == NULL && !quiet)
138 ICL_WARN("no iSER-capable offload found");
139
140 return (im_max);
141 }
142
143 TAILQ_FOREACH(im, &sc->sc_modules, im_next) {
144 if (strcasecmp(im->im_name, name) != 0)
145 continue;
146
147 if (!im->im_iser && iser && !quiet) {
148 ICL_WARN("offload \"%s\" is not iSER-capable", name);
149 return (NULL);
150 }
151 if (im->im_iser && !iser && !quiet) {
152 ICL_WARN("offload \"%s\" is iSER-only", name);
153 return (NULL);
154 }
155
156 return (im);
157 }
158
159 if (!quiet)
160 ICL_WARN("offload \"%s\" not found", name);
161
162 return (NULL);
163 }
164
165 struct icl_conn *
icl_new_conn(const char * offload,bool iser,const char * name,struct mtx * lock)166 icl_new_conn(const char *offload, bool iser, const char *name, struct mtx *lock)
167 {
168 struct icl_module *im;
169 struct icl_conn *ic;
170
171 sx_slock(&sc->sc_lock);
172 im = icl_find(offload, iser, false);
173 if (im == NULL) {
174 sx_sunlock(&sc->sc_lock);
175 return (NULL);
176 }
177
178 ic = im->im_new_conn(name, lock);
179 sx_sunlock(&sc->sc_lock);
180
181 return (ic);
182 }
183
184 int
icl_limits(const char * offload,bool iser,int socket,struct icl_drv_limits * idl)185 icl_limits(const char *offload, bool iser, int socket,
186 struct icl_drv_limits *idl)
187 {
188 struct icl_module *im;
189 int error;
190
191 bzero(idl, sizeof(*idl));
192 sx_slock(&sc->sc_lock);
193 im = icl_find(offload, iser, false);
194 if (im == NULL) {
195 sx_sunlock(&sc->sc_lock);
196 return (ENXIO);
197 }
198
199 error = im->im_limits(idl, socket);
200 sx_sunlock(&sc->sc_lock);
201
202 /*
203 * Validate the limits provided by the driver against values allowed by
204 * the iSCSI RFC. 0 means iscsid/ctld should pick a reasonable value.
205 *
206 * Note that max_send_dsl is an internal implementation detail and not
207 * part of the RFC.
208 */
209 #define OUT_OF_RANGE(x, lo, hi) ((x) != 0 && ((x) < (lo) || (x) > (hi)))
210 if (error == 0 &&
211 (OUT_OF_RANGE(idl->idl_max_recv_data_segment_length, 512, 16777215) ||
212 OUT_OF_RANGE(idl->idl_max_send_data_segment_length, 512, 16777215) ||
213 OUT_OF_RANGE(idl->idl_max_burst_length, 512, 16777215) ||
214 OUT_OF_RANGE(idl->idl_first_burst_length, 512, 16777215))) {
215 error = EINVAL;
216 }
217 #undef OUT_OF_RANGE
218
219 /*
220 * If both first_burst and max_burst are provided then first_burst must
221 * not exceed max_burst.
222 */
223 if (error == 0 && idl->idl_first_burst_length > 0 &&
224 idl->idl_max_burst_length > 0 &&
225 idl->idl_first_burst_length > idl->idl_max_burst_length) {
226 error = EINVAL;
227 }
228
229 return (error);
230 }
231
232 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 *))233 icl_register(const char *offload, bool iser, int priority,
234 int (*limits)(struct icl_drv_limits *, int),
235 struct icl_conn *(*new_conn)(const char *, struct mtx *))
236 {
237 struct icl_module *im;
238
239 sx_xlock(&sc->sc_lock);
240 im = icl_find(offload, iser, true);
241 if (im != NULL) {
242 ICL_WARN("offload \"%s\" already registered", offload);
243 sx_xunlock(&sc->sc_lock);
244 return (EBUSY);
245 }
246
247 im = malloc(sizeof(*im), M_ICL, M_ZERO | M_WAITOK);
248 im->im_name = strdup(offload, M_ICL);
249 im->im_iser = iser;
250 im->im_priority = priority;
251 im->im_limits = limits;
252 im->im_new_conn = new_conn;
253
254 TAILQ_INSERT_HEAD(&sc->sc_modules, im, im_next);
255 sx_xunlock(&sc->sc_lock);
256
257 ICL_DEBUG("offload \"%s\" registered", offload);
258 return (0);
259 }
260
261 int
icl_unregister(const char * offload,bool rdma)262 icl_unregister(const char *offload, bool rdma)
263 {
264 struct icl_module *im;
265
266 sx_xlock(&sc->sc_lock);
267 im = icl_find(offload, rdma, true);
268 if (im == NULL) {
269 ICL_WARN("offload \"%s\" not registered", offload);
270 sx_xunlock(&sc->sc_lock);
271 return (ENXIO);
272 }
273
274 TAILQ_REMOVE(&sc->sc_modules, im, im_next);
275 sx_xunlock(&sc->sc_lock);
276
277 free(im->im_name, M_ICL);
278 free(im, M_ICL);
279
280 ICL_DEBUG("offload \"%s\" unregistered", offload);
281 return (0);
282 }
283
284 static int
icl_load(void)285 icl_load(void)
286 {
287
288 sc = malloc(sizeof(*sc), M_ICL, M_ZERO | M_WAITOK);
289 sx_init(&sc->sc_lock, "icl");
290 TAILQ_INIT(&sc->sc_modules);
291
292 return (0);
293 }
294
295 static int
icl_unload(void)296 icl_unload(void)
297 {
298
299 sx_slock(&sc->sc_lock);
300 KASSERT(TAILQ_EMPTY(&sc->sc_modules), ("still have modules"));
301 sx_sunlock(&sc->sc_lock);
302
303 sx_destroy(&sc->sc_lock);
304 free(sc, M_ICL);
305
306 return (0);
307 }
308
309 static int
icl_modevent(module_t mod,int what,void * arg)310 icl_modevent(module_t mod, int what, void *arg)
311 {
312
313 switch (what) {
314 case MOD_LOAD:
315 return (icl_load());
316 case MOD_UNLOAD:
317 return (icl_unload());
318 default:
319 return (EINVAL);
320 }
321 }
322
323 moduledata_t icl_data = {
324 "icl",
325 icl_modevent,
326 0
327 };
328
329 DECLARE_MODULE(icl, icl_data, SI_SUB_DRIVERS, SI_ORDER_FIRST);
330 MODULE_VERSION(icl, 1);
331