1 /*******************************************************************************
2  * Filename:  target_core_fabric_lib.c
3  *
4  * This file contains generic high level protocol identifier and PR
5  * handlers for TCM fabric modules
6  *
7  * (c) Copyright 2010-2013 Datera, Inc.
8  *
9  * Nicholas A. Bellinger <nab@linux-iscsi.org>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24  *
25  ******************************************************************************/
26 
27 /*
28  * See SPC4, section 7.5 "Protocol specific parameters" for details
29  * on the formats implemented in this file.
30  */
31 
32 #include <linux/kernel.h>
33 #include <linux/string.h>
34 #include <linux/ctype.h>
35 #include <linux/spinlock.h>
36 #include <linux/export.h>
37 
38 #include <scsi/scsi_proto.h>
39 
40 #include <target/target_core_base.h>
41 #include <target/target_core_fabric.h>
42 
43 #include "target_core_internal.h"
44 #include "target_core_pr.h"
45 
46 
47 static int sas_get_pr_transport_id(
48 	struct se_node_acl *nacl,
49 	int *format_code,
50 	unsigned char *buf)
51 {
52 	int ret;
53 
54 	/* Skip over 'naa. prefix */
55 	ret = hex2bin(&buf[4], &nacl->initiatorname[4], 8);
56 	if (ret) {
57 		pr_debug("%s: invalid hex string\n", __func__);
58 		return ret;
59 	}
60 
61 	return 24;
62 }
63 
64 static int fc_get_pr_transport_id(
65 	struct se_node_acl *se_nacl,
66 	int *format_code,
67 	unsigned char *buf)
68 {
69 	unsigned char *ptr;
70 	int i, ret;
71 	u32 off = 8;
72 
73 	/*
74 	 * We convert the ASCII formatted N Port name into a binary
75 	 * encoded TransportID.
76 	 */
77 	ptr = &se_nacl->initiatorname[0];
78 	for (i = 0; i < 24; ) {
79 		if (!strncmp(&ptr[i], ":", 1)) {
80 			i++;
81 			continue;
82 		}
83 		ret = hex2bin(&buf[off++], &ptr[i], 1);
84 		if (ret < 0) {
85 			pr_debug("%s: invalid hex string\n", __func__);
86 			return ret;
87 		}
88 		i += 2;
89 	}
90 	/*
91 	 * The FC Transport ID is a hardcoded 24-byte length
92 	 */
93 	return 24;
94 }
95 
96 static int sbp_get_pr_transport_id(
97 	struct se_node_acl *nacl,
98 	int *format_code,
99 	unsigned char *buf)
100 {
101 	int ret;
102 
103 	ret = hex2bin(&buf[8], nacl->initiatorname, 8);
104 	if (ret) {
105 		pr_debug("%s: invalid hex string\n", __func__);
106 		return ret;
107 	}
108 
109 	return 24;
110 }
111 
112 static int srp_get_pr_transport_id(
113 	struct se_node_acl *nacl,
114 	int *format_code,
115 	unsigned char *buf)
116 {
117 	const char *p;
118 	unsigned len, count, leading_zero_bytes;
119 	int rc;
120 
121 	p = nacl->initiatorname;
122 	if (strncasecmp(p, "0x", 2) == 0)
123 		p += 2;
124 	len = strlen(p);
125 	if (len % 2)
126 		return -EINVAL;
127 
128 	count = min(len / 2, 16U);
129 	leading_zero_bytes = 16 - count;
130 	memset(buf + 8, 0, leading_zero_bytes);
131 	rc = hex2bin(buf + 8 + leading_zero_bytes, p, count);
132 	if (rc < 0) {
133 		pr_debug("hex2bin failed for %s: %d\n", __func__, rc);
134 		return rc;
135 	}
136 
137 	return 24;
138 }
139 
140 static int iscsi_get_pr_transport_id(
141 	struct se_node_acl *se_nacl,
142 	struct t10_pr_registration *pr_reg,
143 	int *format_code,
144 	unsigned char *buf)
145 {
146 	u32 off = 4, padding = 0;
147 	u16 len = 0;
148 
149 	spin_lock_irq(&se_nacl->nacl_sess_lock);
150 	/*
151 	 * From spc4r17 Section 7.5.4.6: TransportID for initiator
152 	 * ports using SCSI over iSCSI.
153 	 *
154 	 * The null-terminated, null-padded (see 4.4.2) ISCSI NAME field
155 	 * shall contain the iSCSI name of an iSCSI initiator node (see
156 	 * RFC 3720). The first ISCSI NAME field byte containing an ASCII
157 	 * null character terminates the ISCSI NAME field without regard for
158 	 * the specified length of the iSCSI TransportID or the contents of
159 	 * the ADDITIONAL LENGTH field.
160 	 */
161 	len = sprintf(&buf[off], "%s", se_nacl->initiatorname);
162 	/*
163 	 * Add Extra byte for NULL terminator
164 	 */
165 	len++;
166 	/*
167 	 * If there is ISID present with the registration and *format code == 1
168 	 * 1, use iSCSI Initiator port TransportID format.
169 	 *
170 	 * Otherwise use iSCSI Initiator device TransportID format that
171 	 * does not contain the ASCII encoded iSCSI Initiator iSID value
172 	 * provied by the iSCSi Initiator during the iSCSI login process.
173 	 */
174 	if ((*format_code == 1) && (pr_reg->isid_present_at_reg)) {
175 		/*
176 		 * Set FORMAT CODE 01b for iSCSI Initiator port TransportID
177 		 * format.
178 		 */
179 		buf[0] |= 0x40;
180 		/*
181 		 * From spc4r17 Section 7.5.4.6: TransportID for initiator
182 		 * ports using SCSI over iSCSI.  Table 390
183 		 *
184 		 * The SEPARATOR field shall contain the five ASCII
185 		 * characters ",i,0x".
186 		 *
187 		 * The null-terminated, null-padded ISCSI INITIATOR SESSION ID
188 		 * field shall contain the iSCSI initiator session identifier
189 		 * (see RFC 3720) in the form of ASCII characters that are the
190 		 * hexadecimal digits converted from the binary iSCSI initiator
191 		 * session identifier value. The first ISCSI INITIATOR SESSION
192 		 * ID field byte containing an ASCII null character
193 		 */
194 		buf[off+len] = 0x2c; off++; /* ASCII Character: "," */
195 		buf[off+len] = 0x69; off++; /* ASCII Character: "i" */
196 		buf[off+len] = 0x2c; off++; /* ASCII Character: "," */
197 		buf[off+len] = 0x30; off++; /* ASCII Character: "0" */
198 		buf[off+len] = 0x78; off++; /* ASCII Character: "x" */
199 		len += 5;
200 		buf[off+len] = pr_reg->pr_reg_isid[0]; off++;
201 		buf[off+len] = pr_reg->pr_reg_isid[1]; off++;
202 		buf[off+len] = pr_reg->pr_reg_isid[2]; off++;
203 		buf[off+len] = pr_reg->pr_reg_isid[3]; off++;
204 		buf[off+len] = pr_reg->pr_reg_isid[4]; off++;
205 		buf[off+len] = pr_reg->pr_reg_isid[5]; off++;
206 		buf[off+len] = '\0'; off++;
207 		len += 7;
208 	}
209 	spin_unlock_irq(&se_nacl->nacl_sess_lock);
210 	/*
211 	 * The ADDITIONAL LENGTH field specifies the number of bytes that follow
212 	 * in the TransportID. The additional length shall be at least 20 and
213 	 * shall be a multiple of four.
214 	*/
215 	padding = ((-len) & 3);
216 	if (padding != 0)
217 		len += padding;
218 
219 	buf[2] = ((len >> 8) & 0xff);
220 	buf[3] = (len & 0xff);
221 	/*
222 	 * Increment value for total payload + header length for
223 	 * full status descriptor
224 	 */
225 	len += 4;
226 
227 	return len;
228 }
229 
230 static int iscsi_get_pr_transport_id_len(
231 	struct se_node_acl *se_nacl,
232 	struct t10_pr_registration *pr_reg,
233 	int *format_code)
234 {
235 	u32 len = 0, padding = 0;
236 
237 	spin_lock_irq(&se_nacl->nacl_sess_lock);
238 	len = strlen(se_nacl->initiatorname);
239 	/*
240 	 * Add extra byte for NULL terminator
241 	 */
242 	len++;
243 	/*
244 	 * If there is ISID present with the registration, use format code:
245 	 * 01b: iSCSI Initiator port TransportID format
246 	 *
247 	 * If there is not an active iSCSI session, use format code:
248 	 * 00b: iSCSI Initiator device TransportID format
249 	 */
250 	if (pr_reg->isid_present_at_reg) {
251 		len += 5; /* For ",i,0x" ASCII separator */
252 		len += 7; /* For iSCSI Initiator Session ID + Null terminator */
253 		*format_code = 1;
254 	} else
255 		*format_code = 0;
256 	spin_unlock_irq(&se_nacl->nacl_sess_lock);
257 	/*
258 	 * The ADDITIONAL LENGTH field specifies the number of bytes that follow
259 	 * in the TransportID. The additional length shall be at least 20 and
260 	 * shall be a multiple of four.
261 	 */
262 	padding = ((-len) & 3);
263 	if (padding != 0)
264 		len += padding;
265 	/*
266 	 * Increment value for total payload + header length for
267 	 * full status descriptor
268 	 */
269 	len += 4;
270 
271 	return len;
272 }
273 
274 static char *iscsi_parse_pr_out_transport_id(
275 	struct se_portal_group *se_tpg,
276 	const char *buf,
277 	u32 *out_tid_len,
278 	char **port_nexus_ptr)
279 {
280 	char *p;
281 	u32 tid_len, padding;
282 	int i;
283 	u16 add_len;
284 	u8 format_code = (buf[0] & 0xc0);
285 	/*
286 	 * Check for FORMAT CODE 00b or 01b from spc4r17, section 7.5.4.6:
287 	 *
288 	 *       TransportID for initiator ports using SCSI over iSCSI,
289 	 *       from Table 388 -- iSCSI TransportID formats.
290 	 *
291 	 *    00b     Initiator port is identified using the world wide unique
292 	 *            SCSI device name of the iSCSI initiator
293 	 *            device containing the initiator port (see table 389).
294 	 *    01b     Initiator port is identified using the world wide unique
295 	 *            initiator port identifier (see table 390).10b to 11b
296 	 *            Reserved
297 	 */
298 	if ((format_code != 0x00) && (format_code != 0x40)) {
299 		pr_err("Illegal format code: 0x%02x for iSCSI"
300 			" Initiator Transport ID\n", format_code);
301 		return NULL;
302 	}
303 	/*
304 	 * If the caller wants the TransportID Length, we set that value for the
305 	 * entire iSCSI Tarnsport ID now.
306 	 */
307 	if (out_tid_len) {
308 		/* The shift works thanks to integer promotion rules */
309 		add_len = (buf[2] << 8) | buf[3];
310 
311 		tid_len = strlen(&buf[4]);
312 		tid_len += 4; /* Add four bytes for iSCSI Transport ID header */
313 		tid_len += 1; /* Add one byte for NULL terminator */
314 		padding = ((-tid_len) & 3);
315 		if (padding != 0)
316 			tid_len += padding;
317 
318 		if ((add_len + 4) != tid_len) {
319 			pr_debug("LIO-Target Extracted add_len: %hu "
320 				"does not match calculated tid_len: %u,"
321 				" using tid_len instead\n", add_len+4, tid_len);
322 			*out_tid_len = tid_len;
323 		} else
324 			*out_tid_len = (add_len + 4);
325 	}
326 	/*
327 	 * Check for ',i,0x' separator between iSCSI Name and iSCSI Initiator
328 	 * Session ID as defined in Table 390 - iSCSI initiator port TransportID
329 	 * format.
330 	 */
331 	if (format_code == 0x40) {
332 		p = strstr(&buf[4], ",i,0x");
333 		if (!p) {
334 			pr_err("Unable to locate \",i,0x\" separator"
335 				" for Initiator port identifier: %s\n",
336 				&buf[4]);
337 			return NULL;
338 		}
339 		*p = '\0'; /* Terminate iSCSI Name */
340 		p += 5; /* Skip over ",i,0x" separator */
341 
342 		*port_nexus_ptr = p;
343 		/*
344 		 * Go ahead and do the lower case conversion of the received
345 		 * 12 ASCII characters representing the ISID in the TransportID
346 		 * for comparison against the running iSCSI session's ISID from
347 		 * iscsi_target.c:lio_sess_get_initiator_sid()
348 		 */
349 		for (i = 0; i < 12; i++) {
350 			if (isdigit(*p)) {
351 				p++;
352 				continue;
353 			}
354 			*p = tolower(*p);
355 			p++;
356 		}
357 	}
358 
359 	return (char *)&buf[4];
360 }
361 
362 int target_get_pr_transport_id_len(struct se_node_acl *nacl,
363 		struct t10_pr_registration *pr_reg, int *format_code)
364 {
365 	switch (nacl->se_tpg->proto_id) {
366 	case SCSI_PROTOCOL_FCP:
367 	case SCSI_PROTOCOL_SBP:
368 	case SCSI_PROTOCOL_SRP:
369 	case SCSI_PROTOCOL_SAS:
370 		break;
371 	case SCSI_PROTOCOL_ISCSI:
372 		return iscsi_get_pr_transport_id_len(nacl, pr_reg, format_code);
373 	default:
374 		pr_err("Unknown proto_id: 0x%02x\n", nacl->se_tpg->proto_id);
375 		return -EINVAL;
376 	}
377 
378 	/*
379 	 * Most transports use a fixed length 24 byte identifier.
380 	 */
381 	*format_code = 0;
382 	return 24;
383 }
384 
385 int target_get_pr_transport_id(struct se_node_acl *nacl,
386 		struct t10_pr_registration *pr_reg, int *format_code,
387 		unsigned char *buf)
388 {
389 	switch (nacl->se_tpg->proto_id) {
390 	case SCSI_PROTOCOL_SAS:
391 		return sas_get_pr_transport_id(nacl, format_code, buf);
392 	case SCSI_PROTOCOL_SBP:
393 		return sbp_get_pr_transport_id(nacl, format_code, buf);
394 	case SCSI_PROTOCOL_SRP:
395 		return srp_get_pr_transport_id(nacl, format_code, buf);
396 	case SCSI_PROTOCOL_FCP:
397 		return fc_get_pr_transport_id(nacl, format_code, buf);
398 	case SCSI_PROTOCOL_ISCSI:
399 		return iscsi_get_pr_transport_id(nacl, pr_reg, format_code,
400 				buf);
401 	default:
402 		pr_err("Unknown proto_id: 0x%02x\n", nacl->se_tpg->proto_id);
403 		return -EINVAL;
404 	}
405 }
406 
407 const char *target_parse_pr_out_transport_id(struct se_portal_group *tpg,
408 		const char *buf, u32 *out_tid_len, char **port_nexus_ptr)
409 {
410 	u32 offset;
411 
412 	switch (tpg->proto_id) {
413 	case SCSI_PROTOCOL_SAS:
414 		/*
415 		 * Assume the FORMAT CODE 00b from spc4r17, 7.5.4.7 TransportID
416 		 * for initiator ports using SCSI over SAS Serial SCSI Protocol.
417 		 */
418 		offset = 4;
419 		break;
420 	case SCSI_PROTOCOL_SBP:
421 	case SCSI_PROTOCOL_SRP:
422 	case SCSI_PROTOCOL_FCP:
423 		offset = 8;
424 		break;
425 	case SCSI_PROTOCOL_ISCSI:
426 		return iscsi_parse_pr_out_transport_id(tpg, buf, out_tid_len,
427 					port_nexus_ptr);
428 	default:
429 		pr_err("Unknown proto_id: 0x%02x\n", tpg->proto_id);
430 		return NULL;
431 	}
432 
433 	*port_nexus_ptr = NULL;
434 	*out_tid_len = 24;
435 	return buf + offset;
436 }
437