xref: /openbsd-src/usr.sbin/iscsid/vscsi.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /*	$OpenBSD: vscsi.c,v 1.14 2014/05/10 11:28:02 claudio Exp $ */
2 
3 /*
4  * Copyright (c) 2009 Claudio Jeker <claudio@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/param.h>	/* for nitems */
21 #include <sys/ioctl.h>
22 #include <sys/queue.h>
23 #include <sys/socket.h>
24 #include <sys/uio.h>
25 
26 #include <scsi/iscsi.h>
27 #include <scsi/scsi_all.h>
28 #include <dev/vscsivar.h>
29 
30 #include <event.h>
31 #include <fcntl.h>
32 #include <stdlib.h>
33 #include <string.h>
34 
35 #include "iscsid.h"
36 #include "log.h"
37 
38 struct vscsi {
39 	struct event		ev;
40 	int			fd;
41 	struct vscsi_stats	stats;
42 } v;
43 
44 struct scsi_task {
45 	struct task	task;
46 	int		tag;
47 	u_int		target;
48 	u_int		lun;
49 	size_t		datalen;
50 };
51 
52 void	vscsi_callback(struct connection *, void *, struct pdu *);
53 void	vscsi_fail(void *arg);
54 void	vscsi_dataout(struct connection *, struct scsi_task *, u_int32_t,
55 	    size_t, size_t);
56 
57 void
58 vscsi_open(char *dev)
59 {
60 	if ((v.fd = open(dev, O_RDWR)) == -1)
61 		fatal("vscsi_open");
62 
63 	event_set(&v.ev, v.fd, EV_READ|EV_PERSIST, vscsi_dispatch, NULL);
64 	event_add(&v.ev, NULL);
65 }
66 
67 void
68 vscsi_dispatch(int fd, short event, void *arg)
69 {
70 	struct vscsi_ioc_i2t i2t;
71 	struct iscsi_pdu_scsi_request *sreq;
72 	struct session *s;
73 	struct scsi_task *t;
74 	struct pdu *p;
75 
76 	if (!(event & EV_READ)) {
77 		log_debug("spurious read call");
78 		return;
79 	}
80 
81 	if (ioctl(v.fd, VSCSI_I2T, &i2t) == -1)
82 		fatal("vscsi_dispatch");
83 
84 	v.stats.cnt_i2t++;
85 	if (i2t.direction < (int)nitems(v.stats.cnt_i2t_dir))
86 		v.stats.cnt_i2t_dir[i2t.direction]++;
87 
88 	s = initiator_t2s(i2t.target);
89 	if (s == NULL)
90 		fatalx("vscsi_dispatch: unknown target");
91 
92 	if (!(t = calloc(1, sizeof(*t))))
93 		fatal("vscsi_dispatch");
94 
95 	t->tag = i2t.tag;
96 	t->target = i2t.target;
97 	t->lun = i2t.lun;
98 
99 	if (!(p = pdu_new()))
100 		fatal("vscsi_dispatch");
101 	if (!(sreq = pdu_gethdr(p)))
102 		fatal("vscsi_dispatch");
103 
104 	sreq->opcode = ISCSI_OP_SCSI_REQUEST;
105 	/* XXX use untagged commands, dlg sais so */
106 	sreq->flags = ISCSI_SCSI_F_F | ISCSI_SCSI_ATTR_UNTAGGED;
107 	if (i2t.direction == VSCSI_DIR_WRITE)
108 		sreq->flags |= ISCSI_SCSI_F_W;
109 	if (i2t.direction == VSCSI_DIR_READ)
110 		sreq->flags |= ISCSI_SCSI_F_R;
111 	sreq->bytes = htonl(i2t.datalen);
112 
113 	/* LUN handling: currently we only do single level LUNs < 256 */
114 	if (t->lun >= 256)
115 		fatal("vscsi_dispatch: I'm sorry, Dave. "
116 		    "I'm afraid I can't do that.");
117 	sreq->lun[1] = t->lun;
118 
119 	memcpy(sreq->cdb, &i2t.cmd, i2t.cmdlen);
120 
121 	/* include immediate data of up to FirstBurstLength bytes if allowed */
122 	if (i2t.direction == VSCSI_DIR_WRITE && s->active.ImmediateData) {
123 		struct connection *c;
124 		char *buf;
125 		u_int32_t t32;
126 		size_t size;
127 
128 		size = i2t.datalen > s->active.FirstBurstLength ?
129 		    s->active.FirstBurstLength : i2t.datalen;
130 
131 		/* XXX assumes all connections have same settings */
132 		c = TAILQ_FIRST(&s->connections);
133 		if (c && size > c->active.MaxRecvDataSegmentLength)
134 			size = c->active.MaxRecvDataSegmentLength;
135 
136 		if (!(buf = pdu_alloc(size)))
137 			fatal("vscsi_dispatch");
138 		t32 = htonl(size);
139 		memcpy(&sreq->ahslen, &t32, sizeof(t32));
140 		vscsi_data(VSCSI_DATA_WRITE, i2t.tag, buf, size);
141 		pdu_addbuf(p, buf, size, PDU_DATA);
142 	}
143 
144 	task_init(&t->task, s, 0, t, vscsi_callback, vscsi_fail);
145 	task_pdu_add(&t->task, p);
146 	session_task_issue(s, &t->task);
147 }
148 
149 /* read / write data to vscsi */
150 void
151 vscsi_data(unsigned long req, int tag, void *buf, size_t len)
152 {
153 	struct vscsi_ioc_data data;
154 
155 	if (req == VSCSI_DATA_READ) {
156 		v.stats.cnt_read++;
157 		v.stats.bytes_rd += len;
158 	} else if (req == VSCSI_DATA_WRITE) {
159 		v.stats.cnt_write++;
160 		v.stats.bytes_wr += len;
161 	}
162 	data.tag = tag;
163 	data.data = buf;
164 	data.datalen = len;
165 
166 	if (ioctl(v.fd, req, &data) == -1)
167 		fatal("vscsi_data");
168 }
169 
170 void
171 vscsi_status(int tag, int status, void *buf, size_t len)
172 {
173 	struct vscsi_ioc_t2i t2i;
174 
175 	v.stats.cnt_t2i++;
176 	if (status < (int)nitems(v.stats.cnt_t2i_status))
177 		v.stats.cnt_t2i_status[status]++;
178 
179 	bzero(&t2i, sizeof(t2i));
180 	t2i.tag = tag;
181 	t2i.status = status;
182 	if (buf) {
183 		if (len > sizeof(t2i.sense))
184 			len = sizeof(t2i.sense);
185 		memcpy(&t2i.sense, buf, len);
186 	}
187 
188 	if (ioctl(v.fd, VSCSI_T2I, &t2i) == -1)
189 		fatal("vscsi_status");
190 }
191 
192 void
193 vscsi_event(unsigned long req, u_int target, u_int lun)
194 {
195 	struct vscsi_ioc_devevent devev;
196 
197 	if (req == VSCSI_REQPROBE)
198 		v.stats.cnt_probe++;
199 	else if (req == VSCSI_REQDETACH)
200 		v.stats.cnt_detach++;
201 
202 	devev.target = target;
203 	devev.lun = lun;
204 
205 	if (ioctl(v.fd, req, &devev) == -1)
206 		fatal("vscsi_event");
207 }
208 
209 void
210 vscsi_callback(struct connection *c, void *arg, struct pdu *p)
211 {
212 	struct scsi_task *t = arg;
213 	struct iscsi_pdu_scsi_response *sresp;
214 	struct iscsi_pdu_rt2 *r2t;
215 	int status = VSCSI_STAT_DONE;
216 	u_char *buf = NULL;
217 	size_t size, off, n;
218 	int tag;
219 
220 	sresp = pdu_getbuf(p, NULL, PDU_HEADER);
221 	switch (ISCSI_PDU_OPCODE(sresp->opcode)) {
222 	case ISCSI_OP_SCSI_RESPONSE:
223 		conn_task_cleanup(c, &t->task);
224 		tag = t->tag;
225 		free(t);
226 
227 		if (!(sresp->flags & 0x80) || (sresp->flags & 0x06) == 0x06 ||
228 		    (sresp->flags & 0x18) == 0x18) {
229 			log_debug("vscsi_callback: bad scsi response");
230 			conn_fail(c);
231 			break;
232 		}
233 		size = 0;
234 		/* XXX handle the various serial numbers */
235 		if (sresp->response) {
236 			status = VSCSI_STAT_ERR;
237 			goto send_status;
238 		}
239 		switch (sresp->status) {
240 		case ISCSI_SCSI_STAT_GOOD:
241 			break;
242 		case ISCSI_SCSI_STAT_CHCK_COND:
243 			status = VSCSI_STAT_SENSE;
244 			/* stupid encoding of sense data in the data segment */
245 			buf = pdu_getbuf(p, &n, PDU_DATA);
246 			if (buf) {
247 				size = buf[0] << 8 | buf[1];
248 				buf += 2;
249 			}
250 			break;
251 		default:
252 			status = VSCSI_STAT_ERR;
253 			break;
254 		}
255 send_status:
256 		vscsi_status(tag, status, buf, size);
257 		break;
258 	case ISCSI_OP_DATA_IN:
259 		buf = pdu_getbuf(p, &n, PDU_DATA);
260 		size = sresp->datalen[0] << 16 | sresp->datalen[1] << 8 |
261 		    sresp->datalen[2];
262 		if (size > n)
263 			fatal("This does not work as it should");
264 		vscsi_data(VSCSI_DATA_READ, t->tag, buf, size);
265 		if (sresp->flags & 1) {			/* XXX magic */
266 			conn_task_cleanup(c, &t->task);
267 			vscsi_status(t->tag, status, NULL, 0);
268 			free(t);
269 		}
270 		break;
271 	case ISCSI_OP_R2T:
272 		conn_task_cleanup(c, &t->task);
273 		r2t = (struct iscsi_pdu_rt2 *)sresp;
274 		off = ntohl(r2t->buffer_offs);
275 		size = ntohl(r2t->desired_datalen);
276 
277 		vscsi_dataout(c, t, r2t->ttt, size, off);
278 		break;
279 	default:
280 		log_debug("scsi task: tag %d, target %d lun %d", t->tag,
281 		    t->target, t->lun);
282 		log_pdu(p, 1);
283 	}
284 	pdu_free(p);
285 }
286 
287 void
288 vscsi_fail(void *arg)
289 {
290 	struct scsi_task *t = arg;
291 
292 	log_debug("vscsi_fail: task failed, reseting it");
293 	vscsi_status(t->tag, VSCSI_STAT_RESET, NULL, 0);
294 }
295 
296 void
297 vscsi_dataout(struct connection *c, struct scsi_task *t, u_int32_t ttt,
298     size_t len, size_t buffer_off)
299 {
300 	struct pdu *p;
301 	struct iscsi_pdu_data_out *dout;
302 	u_char *buf = NULL;
303 	size_t size, off;
304 	u_int32_t t32, dsn = 0;
305 
306 	for (off = 0; off < len; off += size) {
307 		size = len - off > c->active.MaxRecvDataSegmentLength ?
308 		    c->active.MaxRecvDataSegmentLength : len - off;
309 
310 		/* XXX also respect the MaxBurstLength */
311 
312 		if (!(p = pdu_new()))
313 			fatal("vscsi_r2t");
314 		if (!(dout = pdu_gethdr(p)))
315 			fatal("vscsi_r2t");
316 
317 		dout->opcode = ISCSI_OP_DATA_OUT;
318 		if (off + size == len)
319 			dout->flags = 0x80; /* XXX magic value: F flag*/
320 		/* LUN handling: currently we only do single level LUNs < 256 */
321 		dout->lun[1] = t->lun;
322 		dout->ttt = ttt;
323 		dout->datasn = htonl(dsn++);
324 		t32 = htonl(size);
325 		memcpy(&dout->ahslen, &t32, sizeof(t32));
326 
327 		dout->buffer_offs = htonl(buffer_off + off);
328 		if (!(buf = pdu_alloc(size)))
329 			fatal("vscsi_r2t");
330 
331 		vscsi_data(VSCSI_DATA_WRITE, t->tag, buf, size);
332 		pdu_addbuf(p, buf, size, PDU_DATA);
333 		task_pdu_add(&t->task, p);
334 	}
335 	conn_task_issue(c, &t->task);
336 }
337 
338 struct vscsi_stats *
339 vscsi_stats(void)
340 {
341 	return &v.stats;
342 }
343