1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * Filename:  target_core_fabric_lib.c
4  *
5  * This file contains generic high level protocol identifier and PR
6  * handlers for TCM fabric modules
7  *
8  * (c) Copyright 2010-2013 Datera, Inc.
9  *
10  * Nicholas A. Bellinger <nab@linux-iscsi.org>
11  *
12  ******************************************************************************/
13 
14 /*
15  * See SPC4, section 7.5 "Protocol specific parameters" for details
16  * on the formats implemented in this file.
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/ctype.h>
22 #include <linux/spinlock.h>
23 #include <linux/export.h>
24 #include <asm/unaligned.h>
25 
26 #include <scsi/scsi_proto.h>
27 
28 #include <target/target_core_base.h>
29 #include <target/target_core_fabric.h>
30 
31 #include "target_core_internal.h"
32 #include "target_core_pr.h"
33 
34 
35 static int sas_get_pr_transport_id(
36 	struct se_node_acl *nacl,
37 	int *format_code,
38 	unsigned char *buf)
39 {
40 	int ret;
41 
42 	/* Skip over 'naa. prefix */
43 	ret = hex2bin(&buf[4], &nacl->initiatorname[4], 8);
44 	if (ret) {
45 		pr_debug("%s: invalid hex string\n", __func__);
46 		return ret;
47 	}
48 
49 	return 24;
50 }
51 
52 static int fc_get_pr_transport_id(
53 	struct se_node_acl *se_nacl,
54 	int *format_code,
55 	unsigned char *buf)
56 {
57 	unsigned char *ptr;
58 	int i, ret;
59 	u32 off = 8;
60 
61 	/*
62 	 * We convert the ASCII formatted N Port name into a binary
63 	 * encoded TransportID.
64 	 */
65 	ptr = &se_nacl->initiatorname[0];
66 	for (i = 0; i < 23; ) {
67 		if (!strncmp(&ptr[i], ":", 1)) {
68 			i++;
69 			continue;
70 		}
71 		ret = hex2bin(&buf[off++], &ptr[i], 1);
72 		if (ret < 0) {
73 			pr_debug("%s: invalid hex string\n", __func__);
74 			return ret;
75 		}
76 		i += 2;
77 	}
78 	/*
79 	 * The FC Transport ID is a hardcoded 24-byte length
80 	 */
81 	return 24;
82 }
83 
84 static int sbp_get_pr_transport_id(
85 	struct se_node_acl *nacl,
86 	int *format_code,
87 	unsigned char *buf)
88 {
89 	int ret;
90 
91 	ret = hex2bin(&buf[8], nacl->initiatorname, 8);
92 	if (ret) {
93 		pr_debug("%s: invalid hex string\n", __func__);
94 		return ret;
95 	}
96 
97 	return 24;
98 }
99 
100 static int srp_get_pr_transport_id(
101 	struct se_node_acl *nacl,
102 	int *format_code,
103 	unsigned char *buf)
104 {
105 	const char *p;
106 	unsigned len, count, leading_zero_bytes;
107 	int rc;
108 
109 	p = nacl->initiatorname;
110 	if (strncasecmp(p, "0x", 2) == 0)
111 		p += 2;
112 	len = strlen(p);
113 	if (len % 2)
114 		return -EINVAL;
115 
116 	count = min(len / 2, 16U);
117 	leading_zero_bytes = 16 - count;
118 	memset(buf + 8, 0, leading_zero_bytes);
119 	rc = hex2bin(buf + 8 + leading_zero_bytes, p, count);
120 	if (rc < 0) {
121 		pr_debug("hex2bin failed for %s: %d\n", p, rc);
122 		return rc;
123 	}
124 
125 	return 24;
126 }
127 
128 static int iscsi_get_pr_transport_id(
129 	struct se_node_acl *se_nacl,
130 	struct t10_pr_registration *pr_reg,
131 	int *format_code,
132 	unsigned char *buf)
133 {
134 	u32 off = 4, padding = 0;
135 	u16 len = 0;
136 
137 	spin_lock_irq(&se_nacl->nacl_sess_lock);
138 	/*
139 	 * From spc4r17 Section 7.5.4.6: TransportID for initiator
140 	 * ports using SCSI over iSCSI.
141 	 *
142 	 * The null-terminated, null-padded (see 4.4.2) ISCSI NAME field
143 	 * shall contain the iSCSI name of an iSCSI initiator node (see
144 	 * RFC 3720). The first ISCSI NAME field byte containing an ASCII
145 	 * null character terminates the ISCSI NAME field without regard for
146 	 * the specified length of the iSCSI TransportID or the contents of
147 	 * the ADDITIONAL LENGTH field.
148 	 */
149 	len = sprintf(&buf[off], "%s", se_nacl->initiatorname);
150 	/*
151 	 * Add Extra byte for NULL terminator
152 	 */
153 	len++;
154 	/*
155 	 * If there is ISID present with the registration and *format code == 1
156 	 * 1, use iSCSI Initiator port TransportID format.
157 	 *
158 	 * Otherwise use iSCSI Initiator device TransportID format that
159 	 * does not contain the ASCII encoded iSCSI Initiator iSID value
160 	 * provied by the iSCSi Initiator during the iSCSI login process.
161 	 */
162 	if ((*format_code == 1) && (pr_reg->isid_present_at_reg)) {
163 		/*
164 		 * Set FORMAT CODE 01b for iSCSI Initiator port TransportID
165 		 * format.
166 		 */
167 		buf[0] |= 0x40;
168 		/*
169 		 * From spc4r17 Section 7.5.4.6: TransportID for initiator
170 		 * ports using SCSI over iSCSI.  Table 390
171 		 *
172 		 * The SEPARATOR field shall contain the five ASCII
173 		 * characters ",i,0x".
174 		 *
175 		 * The null-terminated, null-padded ISCSI INITIATOR SESSION ID
176 		 * field shall contain the iSCSI initiator session identifier
177 		 * (see RFC 3720) in the form of ASCII characters that are the
178 		 * hexadecimal digits converted from the binary iSCSI initiator
179 		 * session identifier value. The first ISCSI INITIATOR SESSION
180 		 * ID field byte containing an ASCII null character
181 		 */
182 		buf[off+len] = 0x2c; off++; /* ASCII Character: "," */
183 		buf[off+len] = 0x69; off++; /* ASCII Character: "i" */
184 		buf[off+len] = 0x2c; off++; /* ASCII Character: "," */
185 		buf[off+len] = 0x30; off++; /* ASCII Character: "0" */
186 		buf[off+len] = 0x78; off++; /* ASCII Character: "x" */
187 		len += 5;
188 		buf[off+len] = pr_reg->pr_reg_isid[0]; off++;
189 		buf[off+len] = pr_reg->pr_reg_isid[1]; off++;
190 		buf[off+len] = pr_reg->pr_reg_isid[2]; off++;
191 		buf[off+len] = pr_reg->pr_reg_isid[3]; off++;
192 		buf[off+len] = pr_reg->pr_reg_isid[4]; off++;
193 		buf[off+len] = pr_reg->pr_reg_isid[5]; off++;
194 		buf[off+len] = '\0'; off++;
195 		len += 7;
196 	}
197 	spin_unlock_irq(&se_nacl->nacl_sess_lock);
198 	/*
199 	 * The ADDITIONAL LENGTH field specifies the number of bytes that follow
200 	 * in the TransportID. The additional length shall be at least 20 and
201 	 * shall be a multiple of four.
202 	*/
203 	padding = ((-len) & 3);
204 	if (padding != 0)
205 		len += padding;
206 
207 	put_unaligned_be16(len, &buf[2]);
208 	/*
209 	 * Increment value for total payload + header length for
210 	 * full status descriptor
211 	 */
212 	len += 4;
213 
214 	return len;
215 }
216 
217 static int iscsi_get_pr_transport_id_len(
218 	struct se_node_acl *se_nacl,
219 	struct t10_pr_registration *pr_reg,
220 	int *format_code)
221 {
222 	u32 len = 0, padding = 0;
223 
224 	spin_lock_irq(&se_nacl->nacl_sess_lock);
225 	len = strlen(se_nacl->initiatorname);
226 	/*
227 	 * Add extra byte for NULL terminator
228 	 */
229 	len++;
230 	/*
231 	 * If there is ISID present with the registration, use format code:
232 	 * 01b: iSCSI Initiator port TransportID format
233 	 *
234 	 * If there is not an active iSCSI session, use format code:
235 	 * 00b: iSCSI Initiator device TransportID format
236 	 */
237 	if (pr_reg->isid_present_at_reg) {
238 		len += 5; /* For ",i,0x" ASCII separator */
239 		len += 7; /* For iSCSI Initiator Session ID + Null terminator */
240 		*format_code = 1;
241 	} else
242 		*format_code = 0;
243 	spin_unlock_irq(&se_nacl->nacl_sess_lock);
244 	/*
245 	 * The ADDITIONAL LENGTH field specifies the number of bytes that follow
246 	 * in the TransportID. The additional length shall be at least 20 and
247 	 * shall be a multiple of four.
248 	 */
249 	padding = ((-len) & 3);
250 	if (padding != 0)
251 		len += padding;
252 	/*
253 	 * Increment value for total payload + header length for
254 	 * full status descriptor
255 	 */
256 	len += 4;
257 
258 	return len;
259 }
260 
261 static char *iscsi_parse_pr_out_transport_id(
262 	struct se_portal_group *se_tpg,
263 	char *buf,
264 	u32 *out_tid_len,
265 	char **port_nexus_ptr)
266 {
267 	char *p;
268 	u32 tid_len, padding;
269 	int i;
270 	u16 add_len;
271 	u8 format_code = (buf[0] & 0xc0);
272 	/*
273 	 * Check for FORMAT CODE 00b or 01b from spc4r17, section 7.5.4.6:
274 	 *
275 	 *       TransportID for initiator ports using SCSI over iSCSI,
276 	 *       from Table 388 -- iSCSI TransportID formats.
277 	 *
278 	 *    00b     Initiator port is identified using the world wide unique
279 	 *            SCSI device name of the iSCSI initiator
280 	 *            device containing the initiator port (see table 389).
281 	 *    01b     Initiator port is identified using the world wide unique
282 	 *            initiator port identifier (see table 390).10b to 11b
283 	 *            Reserved
284 	 */
285 	if ((format_code != 0x00) && (format_code != 0x40)) {
286 		pr_err("Illegal format code: 0x%02x for iSCSI"
287 			" Initiator Transport ID\n", format_code);
288 		return NULL;
289 	}
290 	/*
291 	 * If the caller wants the TransportID Length, we set that value for the
292 	 * entire iSCSI Tarnsport ID now.
293 	 */
294 	if (out_tid_len) {
295 		/* The shift works thanks to integer promotion rules */
296 		add_len = get_unaligned_be16(&buf[2]);
297 
298 		tid_len = strlen(&buf[4]);
299 		tid_len += 4; /* Add four bytes for iSCSI Transport ID header */
300 		tid_len += 1; /* Add one byte for NULL terminator */
301 		padding = ((-tid_len) & 3);
302 		if (padding != 0)
303 			tid_len += padding;
304 
305 		if ((add_len + 4) != tid_len) {
306 			pr_debug("LIO-Target Extracted add_len: %hu "
307 				"does not match calculated tid_len: %u,"
308 				" using tid_len instead\n", add_len+4, tid_len);
309 			*out_tid_len = tid_len;
310 		} else
311 			*out_tid_len = (add_len + 4);
312 	}
313 	/*
314 	 * Check for ',i,0x' separator between iSCSI Name and iSCSI Initiator
315 	 * Session ID as defined in Table 390 - iSCSI initiator port TransportID
316 	 * format.
317 	 */
318 	if (format_code == 0x40) {
319 		p = strstr(&buf[4], ",i,0x");
320 		if (!p) {
321 			pr_err("Unable to locate \",i,0x\" separator"
322 				" for Initiator port identifier: %s\n",
323 				&buf[4]);
324 			return NULL;
325 		}
326 		*p = '\0'; /* Terminate iSCSI Name */
327 		p += 5; /* Skip over ",i,0x" separator */
328 
329 		*port_nexus_ptr = p;
330 		/*
331 		 * Go ahead and do the lower case conversion of the received
332 		 * 12 ASCII characters representing the ISID in the TransportID
333 		 * for comparison against the running iSCSI session's ISID from
334 		 * iscsi_target.c:lio_sess_get_initiator_sid()
335 		 */
336 		for (i = 0; i < 12; i++) {
337 			if (isdigit(*p)) {
338 				p++;
339 				continue;
340 			}
341 			*p = tolower(*p);
342 			p++;
343 		}
344 	} else
345 		*port_nexus_ptr = NULL;
346 
347 	return &buf[4];
348 }
349 
350 int target_get_pr_transport_id_len(struct se_node_acl *nacl,
351 		struct t10_pr_registration *pr_reg, int *format_code)
352 {
353 	switch (nacl->se_tpg->proto_id) {
354 	case SCSI_PROTOCOL_FCP:
355 	case SCSI_PROTOCOL_SBP:
356 	case SCSI_PROTOCOL_SRP:
357 	case SCSI_PROTOCOL_SAS:
358 		break;
359 	case SCSI_PROTOCOL_ISCSI:
360 		return iscsi_get_pr_transport_id_len(nacl, pr_reg, format_code);
361 	default:
362 		pr_err("Unknown proto_id: 0x%02x\n", nacl->se_tpg->proto_id);
363 		return -EINVAL;
364 	}
365 
366 	/*
367 	 * Most transports use a fixed length 24 byte identifier.
368 	 */
369 	*format_code = 0;
370 	return 24;
371 }
372 
373 int target_get_pr_transport_id(struct se_node_acl *nacl,
374 		struct t10_pr_registration *pr_reg, int *format_code,
375 		unsigned char *buf)
376 {
377 	switch (nacl->se_tpg->proto_id) {
378 	case SCSI_PROTOCOL_SAS:
379 		return sas_get_pr_transport_id(nacl, format_code, buf);
380 	case SCSI_PROTOCOL_SBP:
381 		return sbp_get_pr_transport_id(nacl, format_code, buf);
382 	case SCSI_PROTOCOL_SRP:
383 		return srp_get_pr_transport_id(nacl, format_code, buf);
384 	case SCSI_PROTOCOL_FCP:
385 		return fc_get_pr_transport_id(nacl, format_code, buf);
386 	case SCSI_PROTOCOL_ISCSI:
387 		return iscsi_get_pr_transport_id(nacl, pr_reg, format_code,
388 				buf);
389 	default:
390 		pr_err("Unknown proto_id: 0x%02x\n", nacl->se_tpg->proto_id);
391 		return -EINVAL;
392 	}
393 }
394 
395 const char *target_parse_pr_out_transport_id(struct se_portal_group *tpg,
396 		char *buf, u32 *out_tid_len, char **port_nexus_ptr)
397 {
398 	u32 offset;
399 
400 	switch (tpg->proto_id) {
401 	case SCSI_PROTOCOL_SAS:
402 		/*
403 		 * Assume the FORMAT CODE 00b from spc4r17, 7.5.4.7 TransportID
404 		 * for initiator ports using SCSI over SAS Serial SCSI Protocol.
405 		 */
406 		offset = 4;
407 		break;
408 	case SCSI_PROTOCOL_SBP:
409 	case SCSI_PROTOCOL_SRP:
410 	case SCSI_PROTOCOL_FCP:
411 		offset = 8;
412 		break;
413 	case SCSI_PROTOCOL_ISCSI:
414 		return iscsi_parse_pr_out_transport_id(tpg, buf, out_tid_len,
415 					port_nexus_ptr);
416 	default:
417 		pr_err("Unknown proto_id: 0x%02x\n", tpg->proto_id);
418 		return NULL;
419 	}
420 
421 	*port_nexus_ptr = NULL;
422 	*out_tid_len = 24;
423 	return buf + offset;
424 }
425