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 
sas_get_pr_transport_id(struct se_node_acl * nacl,int * format_code,unsigned char * buf)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 
fc_get_pr_transport_id(struct se_node_acl * se_nacl,int * format_code,unsigned char * buf)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 
sbp_get_pr_transport_id(struct se_node_acl * nacl,int * format_code,unsigned char * buf)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 
srp_get_pr_transport_id(struct se_node_acl * nacl,int * format_code,unsigned char * buf)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 
iscsi_get_pr_transport_id(struct se_node_acl * se_nacl,struct t10_pr_registration * pr_reg,int * format_code,unsigned char * buf)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 	int isid_len;
136 	u16 len = 0;
137 
138 	spin_lock_irq(&se_nacl->nacl_sess_lock);
139 	/*
140 	 * Only null terminate the last field.
141 	 *
142 	 * From spc4r37 section 7.6.4.6: TransportID for initiator ports using
143 	 * SCSI over iSCSI.
144 	 *
145 	 * Table 507 TPID=0 Initiator device TransportID
146 	 *
147 	 * The null-terminated, null-padded (see 4.3.2) ISCSI NAME field shall
148 	 * contain the iSCSI name of an iSCSI initiator node (see RFC 7143).
149 	 * The first ISCSI NAME field byte containing an ASCII null character
150 	 * terminates the ISCSI NAME field without regard for the specified
151 	 * length of the iSCSI TransportID or the contents of the ADDITIONAL
152 	 * LENGTH field.
153 	 */
154 	len = sprintf(&buf[off], "%s", se_nacl->initiatorname);
155 	off += len;
156 	if ((*format_code == 1) && (pr_reg->isid_present_at_reg)) {
157 		/*
158 		 * Set FORMAT CODE 01b for iSCSI Initiator port TransportID
159 		 * format.
160 		 */
161 		buf[0] |= 0x40;
162 		/*
163 		 * From spc4r37 Section 7.6.4.6
164 		 *
165 		 * Table 508 TPID=1 Initiator port TransportID.
166 		 *
167 		 * The ISCSI NAME field shall not be null-terminated
168 		 * (see 4.3.2) and shall not be padded.
169 		 *
170 		 * The SEPARATOR field shall contain the five ASCII
171 		 * characters ",i,0x".
172 		 *
173 		 * The null-terminated, null-padded ISCSI INITIATOR SESSION ID
174 		 * field shall contain the iSCSI initiator session identifier
175 		 * (see RFC 3720) in the form of ASCII characters that are the
176 		 * hexadecimal digits converted from the binary iSCSI initiator
177 		 * session identifier value. The first ISCSI INITIATOR SESSION
178 		 * ID field byte containing an ASCII null character terminates
179 		 * the ISCSI INITIATOR SESSION ID field without regard for the
180 		 * specified length of the iSCSI TransportID or the contents
181 		 * of the ADDITIONAL LENGTH field.
182 		 */
183 		buf[off++] = 0x2c; /* ASCII Character: "," */
184 		buf[off++] = 0x69; /* ASCII Character: "i" */
185 		buf[off++] = 0x2c; /* ASCII Character: "," */
186 		buf[off++] = 0x30; /* ASCII Character: "0" */
187 		buf[off++] = 0x78; /* ASCII Character: "x" */
188 		len += 5;
189 
190 		isid_len = sprintf(buf + off, "%s", pr_reg->pr_reg_isid);
191 		off += isid_len;
192 		len += isid_len;
193 	}
194 	buf[off] = '\0';
195 	len += 1;
196 	spin_unlock_irq(&se_nacl->nacl_sess_lock);
197 	/*
198 	 * The ADDITIONAL LENGTH field specifies the number of bytes that follow
199 	 * in the TransportID. The additional length shall be at least 20 and
200 	 * shall be a multiple of four.
201 	*/
202 	padding = ((-len) & 3);
203 	if (padding != 0)
204 		len += padding;
205 
206 	put_unaligned_be16(len, &buf[2]);
207 	/*
208 	 * Increment value for total payload + header length for
209 	 * full status descriptor
210 	 */
211 	len += 4;
212 
213 	return len;
214 }
215 
iscsi_get_pr_transport_id_len(struct se_node_acl * se_nacl,struct t10_pr_registration * pr_reg,int * format_code)216 static int iscsi_get_pr_transport_id_len(
217 	struct se_node_acl *se_nacl,
218 	struct t10_pr_registration *pr_reg,
219 	int *format_code)
220 {
221 	u32 len = 0, padding = 0;
222 
223 	spin_lock_irq(&se_nacl->nacl_sess_lock);
224 	len = strlen(se_nacl->initiatorname);
225 	/*
226 	 * Add extra byte for NULL terminator
227 	 */
228 	len++;
229 	/*
230 	 * If there is ISID present with the registration, use format code:
231 	 * 01b: iSCSI Initiator port TransportID format
232 	 *
233 	 * If there is not an active iSCSI session, use format code:
234 	 * 00b: iSCSI Initiator device TransportID format
235 	 */
236 	if (pr_reg->isid_present_at_reg) {
237 		len += 5; /* For ",i,0x" ASCII separator */
238 		len += strlen(pr_reg->pr_reg_isid);
239 		*format_code = 1;
240 	} else
241 		*format_code = 0;
242 	spin_unlock_irq(&se_nacl->nacl_sess_lock);
243 	/*
244 	 * The ADDITIONAL LENGTH field specifies the number of bytes that follow
245 	 * in the TransportID. The additional length shall be at least 20 and
246 	 * shall be a multiple of four.
247 	 */
248 	padding = ((-len) & 3);
249 	if (padding != 0)
250 		len += padding;
251 	/*
252 	 * Increment value for total payload + header length for
253 	 * full status descriptor
254 	 */
255 	len += 4;
256 
257 	return len;
258 }
259 
iscsi_parse_pr_out_transport_id(struct se_portal_group * se_tpg,char * buf,u32 * out_tid_len,char ** port_nexus_ptr)260 static char *iscsi_parse_pr_out_transport_id(
261 	struct se_portal_group *se_tpg,
262 	char *buf,
263 	u32 *out_tid_len,
264 	char **port_nexus_ptr)
265 {
266 	char *p;
267 	int i;
268 	u8 format_code = (buf[0] & 0xc0);
269 	/*
270 	 * Check for FORMAT CODE 00b or 01b from spc4r17, section 7.5.4.6:
271 	 *
272 	 *       TransportID for initiator ports using SCSI over iSCSI,
273 	 *       from Table 388 -- iSCSI TransportID formats.
274 	 *
275 	 *    00b     Initiator port is identified using the world wide unique
276 	 *            SCSI device name of the iSCSI initiator
277 	 *            device containing the initiator port (see table 389).
278 	 *    01b     Initiator port is identified using the world wide unique
279 	 *            initiator port identifier (see table 390).10b to 11b
280 	 *            Reserved
281 	 */
282 	if ((format_code != 0x00) && (format_code != 0x40)) {
283 		pr_err("Illegal format code: 0x%02x for iSCSI"
284 			" Initiator Transport ID\n", format_code);
285 		return NULL;
286 	}
287 	/*
288 	 * If the caller wants the TransportID Length, we set that value for the
289 	 * entire iSCSI Tarnsport ID now.
290 	 */
291 	if (out_tid_len) {
292 		/* The shift works thanks to integer promotion rules */
293 		*out_tid_len = get_unaligned_be16(&buf[2]);
294 		/* Add four bytes for iSCSI Transport ID header */
295 		*out_tid_len += 4;
296 	}
297 
298 	/*
299 	 * Check for ',i,0x' separator between iSCSI Name and iSCSI Initiator
300 	 * Session ID as defined in Table 390 - iSCSI initiator port TransportID
301 	 * format.
302 	 */
303 	if (format_code == 0x40) {
304 		p = strstr(&buf[4], ",i,0x");
305 		if (!p) {
306 			pr_err("Unable to locate \",i,0x\" separator"
307 				" for Initiator port identifier: %s\n",
308 				&buf[4]);
309 			return NULL;
310 		}
311 		*p = '\0'; /* Terminate iSCSI Name */
312 		p += 5; /* Skip over ",i,0x" separator */
313 
314 		*port_nexus_ptr = p;
315 		/*
316 		 * Go ahead and do the lower case conversion of the received
317 		 * 12 ASCII characters representing the ISID in the TransportID
318 		 * for comparison against the running iSCSI session's ISID from
319 		 * iscsi_target.c:lio_sess_get_initiator_sid()
320 		 */
321 		for (i = 0; i < 12; i++) {
322 			/*
323 			 * The first ISCSI INITIATOR SESSION ID field byte
324 			 * containing an ASCII null character terminates the
325 			 * ISCSI INITIATOR SESSION ID field without regard for
326 			 * the specified length of the iSCSI TransportID or the
327 			 * contents of the ADDITIONAL LENGTH field.
328 			 */
329 			if (*p == '\0')
330 				break;
331 
332 			if (isdigit(*p)) {
333 				p++;
334 				continue;
335 			}
336 			*p = tolower(*p);
337 			p++;
338 		}
339 	} else
340 		*port_nexus_ptr = NULL;
341 
342 	return &buf[4];
343 }
344 
target_get_pr_transport_id_len(struct se_node_acl * nacl,struct t10_pr_registration * pr_reg,int * format_code)345 int target_get_pr_transport_id_len(struct se_node_acl *nacl,
346 		struct t10_pr_registration *pr_reg, int *format_code)
347 {
348 	switch (nacl->se_tpg->proto_id) {
349 	case SCSI_PROTOCOL_FCP:
350 	case SCSI_PROTOCOL_SBP:
351 	case SCSI_PROTOCOL_SRP:
352 	case SCSI_PROTOCOL_SAS:
353 		break;
354 	case SCSI_PROTOCOL_ISCSI:
355 		return iscsi_get_pr_transport_id_len(nacl, pr_reg, format_code);
356 	default:
357 		pr_err("Unknown proto_id: 0x%02x\n", nacl->se_tpg->proto_id);
358 		return -EINVAL;
359 	}
360 
361 	/*
362 	 * Most transports use a fixed length 24 byte identifier.
363 	 */
364 	*format_code = 0;
365 	return 24;
366 }
367 
target_get_pr_transport_id(struct se_node_acl * nacl,struct t10_pr_registration * pr_reg,int * format_code,unsigned char * buf)368 int target_get_pr_transport_id(struct se_node_acl *nacl,
369 		struct t10_pr_registration *pr_reg, int *format_code,
370 		unsigned char *buf)
371 {
372 	switch (nacl->se_tpg->proto_id) {
373 	case SCSI_PROTOCOL_SAS:
374 		return sas_get_pr_transport_id(nacl, format_code, buf);
375 	case SCSI_PROTOCOL_SBP:
376 		return sbp_get_pr_transport_id(nacl, format_code, buf);
377 	case SCSI_PROTOCOL_SRP:
378 		return srp_get_pr_transport_id(nacl, format_code, buf);
379 	case SCSI_PROTOCOL_FCP:
380 		return fc_get_pr_transport_id(nacl, format_code, buf);
381 	case SCSI_PROTOCOL_ISCSI:
382 		return iscsi_get_pr_transport_id(nacl, pr_reg, format_code,
383 				buf);
384 	default:
385 		pr_err("Unknown proto_id: 0x%02x\n", nacl->se_tpg->proto_id);
386 		return -EINVAL;
387 	}
388 }
389 
target_parse_pr_out_transport_id(struct se_portal_group * tpg,char * buf,u32 * out_tid_len,char ** port_nexus_ptr)390 const char *target_parse_pr_out_transport_id(struct se_portal_group *tpg,
391 		char *buf, u32 *out_tid_len, char **port_nexus_ptr)
392 {
393 	u32 offset;
394 
395 	switch (tpg->proto_id) {
396 	case SCSI_PROTOCOL_SAS:
397 		/*
398 		 * Assume the FORMAT CODE 00b from spc4r17, 7.5.4.7 TransportID
399 		 * for initiator ports using SCSI over SAS Serial SCSI Protocol.
400 		 */
401 		offset = 4;
402 		break;
403 	case SCSI_PROTOCOL_SBP:
404 	case SCSI_PROTOCOL_SRP:
405 	case SCSI_PROTOCOL_FCP:
406 		offset = 8;
407 		break;
408 	case SCSI_PROTOCOL_ISCSI:
409 		return iscsi_parse_pr_out_transport_id(tpg, buf, out_tid_len,
410 					port_nexus_ptr);
411 	default:
412 		pr_err("Unknown proto_id: 0x%02x\n", tpg->proto_id);
413 		return NULL;
414 	}
415 
416 	*port_nexus_ptr = NULL;
417 	*out_tid_len = 24;
418 	return buf + offset;
419 }
420