1 /*
2  * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation; either version 2 of the
7  * License, or any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17  */
18 
19 FILE_LICENCE ( GPL2_OR_LATER );
20 
21 #include <stddef.h>
22 #include <string.h>
23 #include <stdlib.h>
24 #include <stdio.h>
25 #include <errno.h>
26 #include <assert.h>
27 #include <byteswap.h>
28 #include <gpxe/vsprintf.h>
29 #include <gpxe/socket.h>
30 #include <gpxe/xfer.h>
31 #include <gpxe/open.h>
32 #include <gpxe/scsi.h>
33 #include <gpxe/process.h>
34 #include <gpxe/uaccess.h>
35 #include <gpxe/tcpip.h>
36 #include <gpxe/settings.h>
37 #include <gpxe/features.h>
38 #include <gpxe/iscsi.h>
39 
40 /** @file
41  *
42  * iSCSI protocol
43  *
44  */
45 
46 FEATURE ( FEATURE_PROTOCOL, "iSCSI", DHCP_EB_FEATURE_ISCSI, 1 );
47 
48 /** iSCSI initiator name (explicitly specified) */
49 static char *iscsi_explicit_initiator_iqn;
50 
51 /** Default iSCSI initiator name (constructed from hostname) */
52 static char *iscsi_default_initiator_iqn;
53 
54 /** iSCSI initiator username */
55 static char *iscsi_initiator_username;
56 
57 /** iSCSI initiator password */
58 static char *iscsi_initiator_password;
59 
60 /** iSCSI target username */
61 static char *iscsi_target_username;
62 
63 /** iSCSI target password */
64 static char *iscsi_target_password;
65 
66 static void iscsi_start_tx ( struct iscsi_session *iscsi );
67 static void iscsi_start_login ( struct iscsi_session *iscsi );
68 static void iscsi_start_data_out ( struct iscsi_session *iscsi,
69 				   unsigned int datasn );
70 
71 /**
72  * Finish receiving PDU data into buffer
73  *
74  * @v iscsi		iSCSI session
75  */
iscsi_rx_buffered_data_done(struct iscsi_session * iscsi)76 static void iscsi_rx_buffered_data_done ( struct iscsi_session *iscsi ) {
77 	free ( iscsi->rx_buffer );
78 	iscsi->rx_buffer = NULL;
79 }
80 
81 /**
82  * Free iSCSI session
83  *
84  * @v refcnt		Reference counter
85  */
iscsi_free(struct refcnt * refcnt)86 static void iscsi_free ( struct refcnt *refcnt ) {
87 	struct iscsi_session *iscsi =
88 		container_of ( refcnt, struct iscsi_session, refcnt );
89 
90 	free ( iscsi->target_address );
91 	free ( iscsi->target_iqn );
92 	free ( iscsi->initiator_username );
93 	free ( iscsi->initiator_password );
94 	free ( iscsi->target_username );
95 	free ( iscsi->target_password );
96 	chap_finish ( &iscsi->chap );
97 	iscsi_rx_buffered_data_done ( iscsi );
98 	free ( iscsi );
99 }
100 
101 /**
102  * Open iSCSI transport-layer connection
103  *
104  * @v iscsi		iSCSI session
105  * @ret rc		Return status code
106  */
iscsi_open_connection(struct iscsi_session * iscsi)107 static int iscsi_open_connection ( struct iscsi_session *iscsi ) {
108 	struct sockaddr_tcpip target;
109 	int rc;
110 
111 	assert ( iscsi->tx_state == ISCSI_TX_IDLE );
112 	assert ( iscsi->rx_state == ISCSI_RX_BHS );
113 	assert ( iscsi->rx_offset == 0 );
114 
115 	/* Open socket */
116 	memset ( &target, 0, sizeof ( target ) );
117 	target.st_port = htons ( iscsi->target_port );
118 	if ( ( rc = xfer_open_named_socket ( &iscsi->socket, SOCK_STREAM,
119 					     ( struct sockaddr * ) &target,
120 					     iscsi->target_address,
121 					     NULL ) ) != 0 ) {
122 		DBGC ( iscsi, "iSCSI %p could not open socket: %s\n",
123 		       iscsi, strerror ( rc ) );
124 		return rc;
125 	}
126 
127 	/* Enter security negotiation phase */
128 	iscsi->status = ( ISCSI_STATUS_SECURITY_NEGOTIATION_PHASE |
129 			  ISCSI_STATUS_STRINGS_SECURITY );
130 	if ( iscsi->target_username )
131 		iscsi->status |= ISCSI_STATUS_AUTH_REVERSE_REQUIRED;
132 
133 	/* Assign fresh initiator task tag */
134 	iscsi->itt++;
135 
136 	/* Initiate login */
137 	iscsi_start_login ( iscsi );
138 
139 	return 0;
140 }
141 
142 /**
143  * Close iSCSI transport-layer connection
144  *
145  * @v iscsi		iSCSI session
146  * @v rc		Reason for close
147  *
148  * Closes the transport-layer connection and resets the session state
149  * ready to attempt a fresh login.
150  */
iscsi_close_connection(struct iscsi_session * iscsi,int rc)151 static void iscsi_close_connection ( struct iscsi_session *iscsi, int rc ) {
152 
153 	/* Close all data transfer interfaces */
154 	xfer_close ( &iscsi->socket, rc );
155 
156 	/* Clear connection status */
157 	iscsi->status = 0;
158 
159 	/* Reset TX and RX state machines */
160 	iscsi->tx_state = ISCSI_TX_IDLE;
161 	iscsi->rx_state = ISCSI_RX_BHS;
162 	iscsi->rx_offset = 0;
163 
164 	/* Free any temporary dynamically allocated memory */
165 	chap_finish ( &iscsi->chap );
166 	iscsi_rx_buffered_data_done ( iscsi );
167 }
168 
169 /**
170  * Mark iSCSI SCSI operation as complete
171  *
172  * @v iscsi		iSCSI session
173  * @v rc		Return status code
174  *
175  * Note that iscsi_scsi_done() will not close the connection, and must
176  * therefore be called only when the internal state machines are in an
177  * appropriate state, otherwise bad things may happen on the next call
178  * to iscsi_issue().  The general rule is to call iscsi_scsi_done()
179  * only at the end of receiving a PDU; at this point the TX and RX
180  * engines should both be idle.
181  */
iscsi_scsi_done(struct iscsi_session * iscsi,int rc)182 static void iscsi_scsi_done ( struct iscsi_session *iscsi, int rc ) {
183 
184 	assert ( iscsi->tx_state == ISCSI_TX_IDLE );
185 	assert ( iscsi->command != NULL );
186 
187 	iscsi->command->rc = rc;
188 	iscsi->command = NULL;
189 }
190 
191 /****************************************************************************
192  *
193  * iSCSI SCSI command issuing
194  *
195  */
196 
197 /**
198  * Build iSCSI SCSI command BHS
199  *
200  * @v iscsi		iSCSI session
201  *
202  * We don't currently support bidirectional commands (i.e. with both
203  * Data-In and Data-Out segments); these would require providing code
204  * to generate an AHS, and there doesn't seem to be any need for it at
205  * the moment.
206  */
iscsi_start_command(struct iscsi_session * iscsi)207 static void iscsi_start_command ( struct iscsi_session *iscsi ) {
208 	struct iscsi_bhs_scsi_command *command = &iscsi->tx_bhs.scsi_command;
209 
210 	assert ( ! ( iscsi->command->data_in && iscsi->command->data_out ) );
211 
212 	/* Construct BHS and initiate transmission */
213 	iscsi_start_tx ( iscsi );
214 	command->opcode = ISCSI_OPCODE_SCSI_COMMAND;
215 	command->flags = ( ISCSI_FLAG_FINAL |
216 			   ISCSI_COMMAND_ATTR_SIMPLE );
217 	if ( iscsi->command->data_in )
218 		command->flags |= ISCSI_COMMAND_FLAG_READ;
219 	if ( iscsi->command->data_out )
220 		command->flags |= ISCSI_COMMAND_FLAG_WRITE;
221 	/* lengths left as zero */
222 	command->lun = iscsi->lun;
223 	command->itt = htonl ( ++iscsi->itt );
224 	command->exp_len = htonl ( iscsi->command->data_in_len |
225 				   iscsi->command->data_out_len );
226 	command->cmdsn = htonl ( iscsi->cmdsn );
227 	command->expstatsn = htonl ( iscsi->statsn + 1 );
228 	memcpy ( &command->cdb, &iscsi->command->cdb, sizeof ( command->cdb ));
229 	DBGC2 ( iscsi, "iSCSI %p start " SCSI_CDB_FORMAT " %s %#zx\n",
230 		iscsi, SCSI_CDB_DATA ( command->cdb ),
231 		( iscsi->command->data_in ? "in" : "out" ),
232 		( iscsi->command->data_in ?
233 		  iscsi->command->data_in_len :
234 		  iscsi->command->data_out_len ) );
235 }
236 
237 /**
238  * Receive data segment of an iSCSI SCSI response PDU
239  *
240  * @v iscsi		iSCSI session
241  * @v data		Received data
242  * @v len		Length of received data
243  * @v remaining		Data remaining after this data
244  * @ret rc		Return status code
245  */
iscsi_rx_scsi_response(struct iscsi_session * iscsi,const void * data,size_t len,size_t remaining)246 static int iscsi_rx_scsi_response ( struct iscsi_session *iscsi,
247 				    const void *data, size_t len,
248 				    size_t remaining ) {
249 	struct iscsi_bhs_scsi_response *response
250 		= &iscsi->rx_bhs.scsi_response;
251 	int sense_offset;
252 
253 	/* Capture the sense response code as it floats past, if present */
254 	sense_offset = ISCSI_SENSE_RESPONSE_CODE_OFFSET - iscsi->rx_offset;
255 	if ( ( sense_offset >= 0 ) && len ) {
256 		iscsi->command->sense_response =
257 			* ( ( char * ) data + sense_offset );
258 	}
259 
260 	/* Wait for whole SCSI response to arrive */
261 	if ( remaining )
262 		return 0;
263 
264 	/* Record SCSI status code */
265 	iscsi->command->status = response->status;
266 
267 	/* Check for errors */
268 	if ( response->response != ISCSI_RESPONSE_COMMAND_COMPLETE )
269 		return -EIO;
270 
271 	/* Mark as completed */
272 	iscsi_scsi_done ( iscsi, 0 );
273 	return 0;
274 }
275 
276 /**
277  * Receive data segment of an iSCSI data-in PDU
278  *
279  * @v iscsi		iSCSI session
280  * @v data		Received data
281  * @v len		Length of received data
282  * @v remaining		Data remaining after this data
283  * @ret rc		Return status code
284  */
iscsi_rx_data_in(struct iscsi_session * iscsi,const void * data,size_t len,size_t remaining)285 static int iscsi_rx_data_in ( struct iscsi_session *iscsi,
286 			      const void *data, size_t len,
287 			      size_t remaining ) {
288 	struct iscsi_bhs_data_in *data_in = &iscsi->rx_bhs.data_in;
289 	unsigned long offset;
290 
291 	/* Copy data to data-in buffer */
292 	offset = ntohl ( data_in->offset ) + iscsi->rx_offset;
293 	assert ( iscsi->command != NULL );
294 	assert ( iscsi->command->data_in );
295 	assert ( ( offset + len ) <= iscsi->command->data_in_len );
296 	copy_to_user ( iscsi->command->data_in, offset, data, len );
297 
298 	/* Wait for whole SCSI response to arrive */
299 	if ( remaining )
300 		return 0;
301 
302 	/* Mark as completed if status is present */
303 	if ( data_in->flags & ISCSI_DATA_FLAG_STATUS ) {
304 		assert ( ( offset + len ) == iscsi->command->data_in_len );
305 		assert ( data_in->flags & ISCSI_FLAG_FINAL );
306 		iscsi->command->status = data_in->status;
307 		/* iSCSI cannot return an error status via a data-in */
308 		iscsi_scsi_done ( iscsi, 0 );
309 	}
310 
311 	return 0;
312 }
313 
314 /**
315  * Receive data segment of an iSCSI R2T PDU
316  *
317  * @v iscsi		iSCSI session
318  * @v data		Received data
319  * @v len		Length of received data
320  * @v remaining		Data remaining after this data
321  * @ret rc		Return status code
322  */
iscsi_rx_r2t(struct iscsi_session * iscsi,const void * data __unused,size_t len __unused,size_t remaining __unused)323 static int iscsi_rx_r2t ( struct iscsi_session *iscsi,
324 			  const void *data __unused, size_t len __unused,
325 			  size_t remaining __unused ) {
326 	struct iscsi_bhs_r2t *r2t = &iscsi->rx_bhs.r2t;
327 
328 	/* Record transfer parameters and trigger first data-out */
329 	iscsi->ttt = ntohl ( r2t->ttt );
330 	iscsi->transfer_offset = ntohl ( r2t->offset );
331 	iscsi->transfer_len = ntohl ( r2t->len );
332 	iscsi_start_data_out ( iscsi, 0 );
333 
334 	return 0;
335 }
336 
337 /**
338  * Build iSCSI data-out BHS
339  *
340  * @v iscsi		iSCSI session
341  * @v datasn		Data sequence number within the transfer
342  *
343  */
iscsi_start_data_out(struct iscsi_session * iscsi,unsigned int datasn)344 static void iscsi_start_data_out ( struct iscsi_session *iscsi,
345 				   unsigned int datasn ) {
346 	struct iscsi_bhs_data_out *data_out = &iscsi->tx_bhs.data_out;
347 	unsigned long offset;
348 	unsigned long remaining;
349 	unsigned long len;
350 
351 	/* We always send 512-byte Data-Out PDUs; this removes the
352 	 * need to worry about the target's MaxRecvDataSegmentLength.
353 	 */
354 	offset = datasn * 512;
355 	remaining = iscsi->transfer_len - offset;
356 	len = remaining;
357 	if ( len > 512 )
358 		len = 512;
359 
360 	/* Construct BHS and initiate transmission */
361 	iscsi_start_tx ( iscsi );
362 	data_out->opcode = ISCSI_OPCODE_DATA_OUT;
363 	if ( len == remaining )
364 		data_out->flags = ( ISCSI_FLAG_FINAL );
365 	ISCSI_SET_LENGTHS ( data_out->lengths, 0, len );
366 	data_out->lun = iscsi->lun;
367 	data_out->itt = htonl ( iscsi->itt );
368 	data_out->ttt = htonl ( iscsi->ttt );
369 	data_out->expstatsn = htonl ( iscsi->statsn + 1 );
370 	data_out->datasn = htonl ( datasn );
371 	data_out->offset = htonl ( iscsi->transfer_offset + offset );
372 	DBGC ( iscsi, "iSCSI %p start data out DataSN %#x len %#lx\n",
373 	       iscsi, datasn, len );
374 }
375 
376 /**
377  * Complete iSCSI data-out PDU transmission
378  *
379  * @v iscsi		iSCSI session
380  *
381  */
iscsi_data_out_done(struct iscsi_session * iscsi)382 static void iscsi_data_out_done ( struct iscsi_session *iscsi ) {
383 	struct iscsi_bhs_data_out *data_out = &iscsi->tx_bhs.data_out;
384 
385 	/* If we haven't reached the end of the sequence, start
386 	 * sending the next data-out PDU.
387 	 */
388 	if ( ! ( data_out->flags & ISCSI_FLAG_FINAL ) )
389 		iscsi_start_data_out ( iscsi, ntohl ( data_out->datasn ) + 1 );
390 }
391 
392 /**
393  * Send iSCSI data-out data segment
394  *
395  * @v iscsi		iSCSI session
396  * @ret rc		Return status code
397  */
iscsi_tx_data_out(struct iscsi_session * iscsi)398 static int iscsi_tx_data_out ( struct iscsi_session *iscsi ) {
399 	struct iscsi_bhs_data_out *data_out = &iscsi->tx_bhs.data_out;
400 	struct io_buffer *iobuf;
401 	unsigned long offset;
402 	size_t len;
403 
404 	offset = ntohl ( data_out->offset );
405 	len = ISCSI_DATA_LEN ( data_out->lengths );
406 
407 	assert ( iscsi->command != NULL );
408 	assert ( iscsi->command->data_out );
409 	assert ( ( offset + len ) <= iscsi->command->data_out_len );
410 
411 	iobuf = xfer_alloc_iob ( &iscsi->socket, len );
412 	if ( ! iobuf )
413 		return -ENOMEM;
414 
415 	copy_from_user ( iob_put ( iobuf, len ),
416 			 iscsi->command->data_out, offset, len );
417 
418 	return xfer_deliver_iob ( &iscsi->socket, iobuf );
419 }
420 
421 /****************************************************************************
422  *
423  * iSCSI login
424  *
425  */
426 
427 /**
428  * Build iSCSI login request strings
429  *
430  * @v iscsi		iSCSI session
431  *
432  * These are the initial set of strings sent in the first login
433  * request PDU.  We want the following settings:
434  *
435  *     HeaderDigest=None
436  *     DataDigest=None
437  *     MaxConnections is irrelevant; we make only one connection anyway
438  *     InitialR2T=Yes [1]
439  *     ImmediateData is irrelevant; we never send immediate data
440  *     MaxRecvDataSegmentLength=8192 (default; we don't care) [3]
441  *     MaxBurstLength=262144 (default; we don't care) [3]
442  *     FirstBurstLength=262144 (default; we don't care)
443  *     DefaultTime2Wait=0 [2]
444  *     DefaultTime2Retain=0 [2]
445  *     MaxOutstandingR2T=1
446  *     DataPDUInOrder=Yes
447  *     DataSequenceInOrder=Yes
448  *     ErrorRecoveryLevel=0
449  *
450  * [1] InitialR2T has an OR resolution function, so the target may
451  * force us to use it.  We therefore simplify our logic by always
452  * using it.
453  *
454  * [2] These ensure that we can safely start a new task once we have
455  * reconnected after a failure, without having to manually tidy up
456  * after the old one.
457  *
458  * [3] We are quite happy to use the RFC-defined default values for
459  * these parameters, but some targets (notably OpenSolaris)
460  * incorrectly assume a default value of zero, so we explicitly
461  * specify the default values.
462  */
iscsi_build_login_request_strings(struct iscsi_session * iscsi,void * data,size_t len)463 static int iscsi_build_login_request_strings ( struct iscsi_session *iscsi,
464 					       void *data, size_t len ) {
465 	unsigned int used = 0;
466 	unsigned int i;
467 	const char *auth_method;
468 
469 	if ( iscsi->status & ISCSI_STATUS_STRINGS_SECURITY ) {
470 		/* Default to allowing no authentication */
471 		auth_method = "None";
472 		/* If we have a credential to supply, permit CHAP */
473 		if ( iscsi->initiator_username )
474 			auth_method = "CHAP,None";
475 		/* If we have a credential to check, force CHAP */
476 		if ( iscsi->target_username )
477 			auth_method = "CHAP";
478 		used += ssnprintf ( data + used, len - used,
479 				    "InitiatorName=%s%c"
480 				    "TargetName=%s%c"
481 				    "SessionType=Normal%c"
482 				    "AuthMethod=%s%c",
483 				    iscsi_initiator_iqn(), 0,
484 				    iscsi->target_iqn, 0, 0,
485 				    auth_method, 0 );
486 	}
487 
488 	if ( iscsi->status & ISCSI_STATUS_STRINGS_CHAP_ALGORITHM ) {
489 		used += ssnprintf ( data + used, len - used, "CHAP_A=5%c", 0 );
490 	}
491 
492 	if ( ( iscsi->status & ISCSI_STATUS_STRINGS_CHAP_RESPONSE ) ) {
493 		assert ( iscsi->initiator_username != NULL );
494 		used += ssnprintf ( data + used, len - used,
495 				    "CHAP_N=%s%cCHAP_R=0x",
496 				    iscsi->initiator_username, 0 );
497 		for ( i = 0 ; i < iscsi->chap.response_len ; i++ ) {
498 			used += ssnprintf ( data + used, len - used, "%02x",
499 					    iscsi->chap.response[i] );
500 		}
501 		used += ssnprintf ( data + used, len - used, "%c", 0 );
502 	}
503 
504 	if ( ( iscsi->status & ISCSI_STATUS_STRINGS_CHAP_CHALLENGE ) ) {
505 		used += ssnprintf ( data + used, len - used,
506 				    "CHAP_I=%d%cCHAP_C=0x",
507 				    iscsi->chap_challenge[0], 0 );
508 		for ( i = 1 ; i < sizeof ( iscsi->chap_challenge ) ; i++ ) {
509 			used += ssnprintf ( data + used, len - used, "%02x",
510 					    iscsi->chap_challenge[i] );
511 		}
512 		used += ssnprintf ( data + used, len - used, "%c", 0 );
513 	}
514 
515 	if ( iscsi->status & ISCSI_STATUS_STRINGS_OPERATIONAL ) {
516 		used += ssnprintf ( data + used, len - used,
517 				    "HeaderDigest=None%c"
518 				    "DataDigest=None%c"
519 				    "InitialR2T=Yes%c"
520 				    "MaxRecvDataSegmentLength=8192%c"
521 				    "MaxBurstLength=262144%c"
522 				    "DefaultTime2Wait=0%c"
523 				    "DefaultTime2Retain=0%c"
524 				    "MaxOutstandingR2T=1%c"
525 				    "DataPDUInOrder=Yes%c"
526 				    "DataSequenceInOrder=Yes%c"
527 				    "ErrorRecoveryLevel=0%c",
528 				    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 );
529 	}
530 
531 	return used;
532 }
533 
534 /**
535  * Build iSCSI login request BHS
536  *
537  * @v iscsi		iSCSI session
538  */
iscsi_start_login(struct iscsi_session * iscsi)539 static void iscsi_start_login ( struct iscsi_session *iscsi ) {
540 	struct iscsi_bhs_login_request *request = &iscsi->tx_bhs.login_request;
541 	int len;
542 
543 	/* Construct BHS and initiate transmission */
544 	iscsi_start_tx ( iscsi );
545 	request->opcode = ( ISCSI_OPCODE_LOGIN_REQUEST |
546 			    ISCSI_FLAG_IMMEDIATE );
547 	request->flags = ( ( iscsi->status & ISCSI_STATUS_PHASE_MASK ) |
548 			   ISCSI_LOGIN_FLAG_TRANSITION );
549 	/* version_max and version_min left as zero */
550 	len = iscsi_build_login_request_strings ( iscsi, NULL, 0 );
551 	ISCSI_SET_LENGTHS ( request->lengths, 0, len );
552 	request->isid_iana_en = htonl ( ISCSI_ISID_IANA |
553 					IANA_EN_FEN_SYSTEMS );
554 	/* isid_iana_qual left as zero */
555 	request->tsih = htons ( iscsi->tsih );
556 	request->itt = htonl ( iscsi->itt );
557 	/* cid left as zero */
558 	request->cmdsn = htonl ( iscsi->cmdsn );
559 	request->expstatsn = htonl ( iscsi->statsn + 1 );
560 }
561 
562 /**
563  * Complete iSCSI login request PDU transmission
564  *
565  * @v iscsi		iSCSI session
566  *
567  */
iscsi_login_request_done(struct iscsi_session * iscsi)568 static void iscsi_login_request_done ( struct iscsi_session *iscsi ) {
569 
570 	/* Clear any "strings to send" flags */
571 	iscsi->status &= ~ISCSI_STATUS_STRINGS_MASK;
572 
573 	/* Free any dynamically allocated storage used for login */
574 	chap_finish ( &iscsi->chap );
575 }
576 
577 /**
578  * Transmit data segment of an iSCSI login request PDU
579  *
580  * @v iscsi		iSCSI session
581  * @ret rc		Return status code
582  *
583  * For login requests, the data segment consists of the login strings.
584  */
iscsi_tx_login_request(struct iscsi_session * iscsi)585 static int iscsi_tx_login_request ( struct iscsi_session *iscsi ) {
586 	struct iscsi_bhs_login_request *request = &iscsi->tx_bhs.login_request;
587 	struct io_buffer *iobuf;
588 	size_t len;
589 
590 	len = ISCSI_DATA_LEN ( request->lengths );
591 	iobuf = xfer_alloc_iob ( &iscsi->socket, len );
592 	if ( ! iobuf )
593 		return -ENOMEM;
594 	iob_put ( iobuf, len );
595 	iscsi_build_login_request_strings ( iscsi, iobuf->data, len );
596 	return xfer_deliver_iob ( &iscsi->socket, iobuf );
597 }
598 
599 /**
600  * Handle iSCSI TargetAddress text value
601  *
602  * @v iscsi		iSCSI session
603  * @v value		TargetAddress value
604  * @ret rc		Return status code
605  */
iscsi_handle_targetaddress_value(struct iscsi_session * iscsi,const char * value)606 static int iscsi_handle_targetaddress_value ( struct iscsi_session *iscsi,
607 					      const char *value ) {
608 	char *separator;
609 
610 	DBGC ( iscsi, "iSCSI %p will redirect to %s\n", iscsi, value );
611 
612 	/* Replace target address */
613 	free ( iscsi->target_address );
614 	iscsi->target_address = strdup ( value );
615 	if ( ! iscsi->target_address )
616 		return -ENOMEM;
617 
618 	/* Replace target port */
619 	iscsi->target_port = htons ( ISCSI_PORT );
620 	separator = strchr ( iscsi->target_address, ':' );
621 	if ( separator ) {
622 		*separator = '\0';
623 		iscsi->target_port = strtoul ( ( separator + 1 ), NULL, 0 );
624 	}
625 
626 	return 0;
627 }
628 
629 /**
630  * Handle iSCSI AuthMethod text value
631  *
632  * @v iscsi		iSCSI session
633  * @v value		AuthMethod value
634  * @ret rc		Return status code
635  */
iscsi_handle_authmethod_value(struct iscsi_session * iscsi,const char * value)636 static int iscsi_handle_authmethod_value ( struct iscsi_session *iscsi,
637 					   const char *value ) {
638 
639 	/* If server requests CHAP, send the CHAP_A string */
640 	if ( strcmp ( value, "CHAP" ) == 0 ) {
641 		DBGC ( iscsi, "iSCSI %p initiating CHAP authentication\n",
642 		       iscsi );
643 		iscsi->status |= ( ISCSI_STATUS_STRINGS_CHAP_ALGORITHM |
644 				   ISCSI_STATUS_AUTH_FORWARD_REQUIRED );
645 	}
646 
647 	return 0;
648 }
649 
650 /**
651  * Handle iSCSI CHAP_A text value
652  *
653  * @v iscsi		iSCSI session
654  * @v value		CHAP_A value
655  * @ret rc		Return status code
656  */
iscsi_handle_chap_a_value(struct iscsi_session * iscsi,const char * value)657 static int iscsi_handle_chap_a_value ( struct iscsi_session *iscsi,
658 				       const char *value ) {
659 
660 	/* We only ever offer "5" (i.e. MD5) as an algorithm, so if
661 	 * the server responds with anything else it is a protocol
662 	 * violation.
663 	 */
664 	if ( strcmp ( value, "5" ) != 0 ) {
665 		DBGC ( iscsi, "iSCSI %p got invalid CHAP algorithm \"%s\"\n",
666 		       iscsi, value );
667 		return -EPROTO;
668 	}
669 
670 	return 0;
671 }
672 
673 /**
674  * Handle iSCSI CHAP_I text value
675  *
676  * @v iscsi		iSCSI session
677  * @v value		CHAP_I value
678  * @ret rc		Return status code
679  */
iscsi_handle_chap_i_value(struct iscsi_session * iscsi,const char * value)680 static int iscsi_handle_chap_i_value ( struct iscsi_session *iscsi,
681 				       const char *value ) {
682 	unsigned int identifier;
683 	char *endp;
684 	int rc;
685 
686 	/* The CHAP identifier is an integer value */
687 	identifier = strtoul ( value, &endp, 0 );
688 	if ( *endp != '\0' ) {
689 		DBGC ( iscsi, "iSCSI %p saw invalid CHAP identifier \"%s\"\n",
690 		       iscsi, value );
691 		return -EPROTO;
692 	}
693 
694 	/* Prepare for CHAP with MD5 */
695 	chap_finish ( &iscsi->chap );
696 	if ( ( rc = chap_init ( &iscsi->chap, &md5_algorithm ) ) != 0 ) {
697 		DBGC ( iscsi, "iSCSI %p could not initialise CHAP: %s\n",
698 		       iscsi, strerror ( rc ) );
699 		return rc;
700 	}
701 
702 	/* Identifier and secret are the first two components of the
703 	 * challenge.
704 	 */
705 	chap_set_identifier ( &iscsi->chap, identifier );
706 	if ( iscsi->initiator_password ) {
707 		chap_update ( &iscsi->chap, iscsi->initiator_password,
708 			      strlen ( iscsi->initiator_password ) );
709 	}
710 
711 	return 0;
712 }
713 
714 /**
715  * Handle iSCSI CHAP_C text value
716  *
717  * @v iscsi		iSCSI session
718  * @v value		CHAP_C value
719  * @ret rc		Return status code
720  */
iscsi_handle_chap_c_value(struct iscsi_session * iscsi,const char * value)721 static int iscsi_handle_chap_c_value ( struct iscsi_session *iscsi,
722 				       const char *value ) {
723 	char buf[3];
724 	char *endp;
725 	uint8_t byte;
726 	unsigned int i;
727 
728 	/* Check and strip leading "0x" */
729 	if ( ( value[0] != '0' ) || ( value[1] != 'x' ) ) {
730 		DBGC ( iscsi, "iSCSI %p saw invalid CHAP challenge \"%s\"\n",
731 		       iscsi, value );
732 		return -EPROTO;
733 	}
734 	value += 2;
735 
736 	/* Process challenge an octet at a time */
737 	for ( ; ( value[0] && value[1] ) ; value += 2 ) {
738 		memcpy ( buf, value, 2 );
739 		buf[2] = 0;
740 		byte = strtoul ( buf, &endp, 16 );
741 		if ( *endp != '\0' ) {
742 			DBGC ( iscsi, "iSCSI %p saw invalid CHAP challenge "
743 			       "byte \"%s\"\n", iscsi, buf );
744 			return -EPROTO;
745 		}
746 		chap_update ( &iscsi->chap, &byte, sizeof ( byte ) );
747 	}
748 
749 	/* Build CHAP response */
750 	DBGC ( iscsi, "iSCSI %p sending CHAP response\n", iscsi );
751 	chap_respond ( &iscsi->chap );
752 	iscsi->status |= ISCSI_STATUS_STRINGS_CHAP_RESPONSE;
753 
754 	/* Send CHAP challenge, if applicable */
755 	if ( iscsi->target_username ) {
756 		iscsi->status |= ISCSI_STATUS_STRINGS_CHAP_CHALLENGE;
757 		/* Generate CHAP challenge data */
758 		for ( i = 0 ; i < sizeof ( iscsi->chap_challenge ) ; i++ ) {
759 			iscsi->chap_challenge[i] = random();
760 		}
761 	}
762 
763 	return 0;
764 }
765 
766 /**
767  * Handle iSCSI CHAP_N text value
768  *
769  * @v iscsi		iSCSI session
770  * @v value		CHAP_N value
771  * @ret rc		Return status code
772  */
iscsi_handle_chap_n_value(struct iscsi_session * iscsi,const char * value)773 static int iscsi_handle_chap_n_value ( struct iscsi_session *iscsi,
774 				       const char *value ) {
775 
776 	/* The target username isn't actually involved at any point in
777 	 * the authentication process; it merely serves to identify
778 	 * which password the target is using to generate the CHAP
779 	 * response.  We unnecessarily verify that the username is as
780 	 * expected, in order to provide mildly helpful diagnostics if
781 	 * the target is supplying the wrong username/password
782 	 * combination.
783 	 */
784 	if ( iscsi->target_username &&
785 	     ( strcmp ( iscsi->target_username, value ) != 0 ) ) {
786 		DBGC ( iscsi, "iSCSI %p target username \"%s\" incorrect "
787 		       "(wanted \"%s\")\n",
788 		       iscsi, value, iscsi->target_username );
789 		return -EACCES;
790 	}
791 
792 	return 0;
793 }
794 
795 /**
796  * Handle iSCSI CHAP_R text value
797  *
798  * @v iscsi		iSCSI session
799  * @v value		CHAP_R value
800  * @ret rc		Return status code
801  */
iscsi_handle_chap_r_value(struct iscsi_session * iscsi,const char * value)802 static int iscsi_handle_chap_r_value ( struct iscsi_session *iscsi,
803 				       const char *value ) {
804 	char buf[3];
805 	char *endp;
806 	uint8_t byte;
807 	unsigned int i;
808 	int rc;
809 
810 	/* Generate CHAP response for verification */
811 	chap_finish ( &iscsi->chap );
812 	if ( ( rc = chap_init ( &iscsi->chap, &md5_algorithm ) ) != 0 ) {
813 		DBGC ( iscsi, "iSCSI %p could not initialise CHAP: %s\n",
814 		       iscsi, strerror ( rc ) );
815 		return rc;
816 	}
817 	chap_set_identifier ( &iscsi->chap, iscsi->chap_challenge[0] );
818 	if ( iscsi->target_password ) {
819 		chap_update ( &iscsi->chap, iscsi->target_password,
820 			      strlen ( iscsi->target_password ) );
821 	}
822 	chap_update ( &iscsi->chap, &iscsi->chap_challenge[1],
823 		      ( sizeof ( iscsi->chap_challenge ) - 1 ) );
824 	chap_respond ( &iscsi->chap );
825 
826 	/* Check and strip leading "0x" */
827 	if ( ( value[0] != '0' ) || ( value[1] != 'x' ) ) {
828 		DBGC ( iscsi, "iSCSI %p saw invalid CHAP response \"%s\"\n",
829 		       iscsi, value );
830 		return -EPROTO;
831 	}
832 	value += 2;
833 
834 	/* Check CHAP response length */
835 	if ( strlen ( value ) != ( 2 * iscsi->chap.response_len ) ) {
836 		DBGC ( iscsi, "iSCSI %p invalid CHAP response length\n",
837 		       iscsi );
838 		return -EPROTO;
839 	}
840 
841 	/* Process response an octet at a time */
842 	for ( i = 0 ; ( value[0] && value[1] ) ; value += 2, i++ ) {
843 		memcpy ( buf, value, 2 );
844 		buf[2] = 0;
845 		byte = strtoul ( buf, &endp, 16 );
846 		if ( *endp != '\0' ) {
847 			DBGC ( iscsi, "iSCSI %p saw invalid CHAP response "
848 			       "byte \"%s\"\n", iscsi, buf );
849 			return -EPROTO;
850 		}
851 		if ( byte != iscsi->chap.response[i] ) {
852 			DBGC ( iscsi, "iSCSI %p saw incorrect CHAP "
853 			       "response\n", iscsi );
854 			return -EACCES;
855 		}
856 	}
857 	assert ( i == iscsi->chap.response_len );
858 
859 	/* Mark session as authenticated */
860 	iscsi->status |= ISCSI_STATUS_AUTH_REVERSE_OK;
861 
862 	return 0;
863 }
864 
865 /** An iSCSI text string that we want to handle */
866 struct iscsi_string_type {
867 	/** String key
868 	 *
869 	 * This is the portion up to and including the "=" sign,
870 	 * e.g. "InitiatorName=", "CHAP_A=", etc.
871 	 */
872 	const char *key;
873 	/** Handle iSCSI string value
874 	 *
875 	 * @v iscsi		iSCSI session
876 	 * @v value		iSCSI string value
877 	 * @ret rc		Return status code
878 	 */
879 	int ( * handle ) ( struct iscsi_session *iscsi, const char *value );
880 };
881 
882 /** iSCSI text strings that we want to handle */
883 static struct iscsi_string_type iscsi_string_types[] = {
884 	{ "TargetAddress=", iscsi_handle_targetaddress_value },
885 	{ "AuthMethod=", iscsi_handle_authmethod_value },
886 	{ "CHAP_A=", iscsi_handle_chap_a_value },
887 	{ "CHAP_I=", iscsi_handle_chap_i_value },
888 	{ "CHAP_C=", iscsi_handle_chap_c_value },
889 	{ "CHAP_N=", iscsi_handle_chap_n_value },
890 	{ "CHAP_R=", iscsi_handle_chap_r_value },
891 	{ NULL, NULL }
892 };
893 
894 /**
895  * Handle iSCSI string
896  *
897  * @v iscsi		iSCSI session
898  * @v string		iSCSI string (in "key=value" format)
899  * @ret rc		Return status code
900  */
iscsi_handle_string(struct iscsi_session * iscsi,const char * string)901 static int iscsi_handle_string ( struct iscsi_session *iscsi,
902 				 const char *string ) {
903 	struct iscsi_string_type *type;
904 	size_t key_len;
905 	int rc;
906 
907 	for ( type = iscsi_string_types ; type->key ; type++ ) {
908 		key_len = strlen ( type->key );
909 		if ( strncmp ( string, type->key, key_len ) != 0 )
910 			continue;
911 		DBGC ( iscsi, "iSCSI %p handling %s\n", iscsi, string );
912 		if ( ( rc = type->handle ( iscsi,
913 					   ( string + key_len ) ) ) != 0 ) {
914 			DBGC ( iscsi, "iSCSI %p could not handle %s: %s\n",
915 			       iscsi, string, strerror ( rc ) );
916 			return rc;
917 		}
918 		return 0;
919 	}
920 	DBGC ( iscsi, "iSCSI %p ignoring %s\n", iscsi, string );
921 	return 0;
922 }
923 
924 /**
925  * Handle iSCSI strings
926  *
927  * @v iscsi		iSCSI session
928  * @v string		iSCSI string buffer
929  * @v len		Length of string buffer
930  * @ret rc		Return status code
931  */
iscsi_handle_strings(struct iscsi_session * iscsi,const char * strings,size_t len)932 static int iscsi_handle_strings ( struct iscsi_session *iscsi,
933 				  const char *strings, size_t len ) {
934 	size_t string_len;
935 	int rc;
936 
937 	/* Handle each string in turn, taking care not to overrun the
938 	 * data buffer in case of badly-terminated data.
939 	 */
940 	while ( 1 ) {
941 		string_len = ( strnlen ( strings, len ) + 1 );
942 		if ( string_len > len )
943 			break;
944 		if ( ( rc = iscsi_handle_string ( iscsi, strings ) ) != 0 )
945 			return rc;
946 		strings += string_len;
947 		len -= string_len;
948 	}
949 	return 0;
950 }
951 
952 /**
953  * Receive PDU data into buffer
954  *
955  * @v iscsi		iSCSI session
956  * @v data		Data to receive
957  * @v len		Length of data
958  * @ret rc		Return status code
959  *
960  * This can be used when the RX PDU type handler wishes to buffer up
961  * all received data and process the PDU as a single unit.  The caller
962  * is repsonsible for calling iscsi_rx_buffered_data_done() after
963  * processing the data.
964  */
iscsi_rx_buffered_data(struct iscsi_session * iscsi,const void * data,size_t len)965 static int iscsi_rx_buffered_data ( struct iscsi_session *iscsi,
966 				    const void *data, size_t len ) {
967 
968 	/* Allocate buffer on first call */
969 	if ( ! iscsi->rx_buffer ) {
970 		iscsi->rx_buffer = malloc ( iscsi->rx_len );
971 		if ( ! iscsi->rx_buffer )
972 			return -ENOMEM;
973 	}
974 
975 	/* Copy data to buffer */
976 	assert ( ( iscsi->rx_offset + len ) <= iscsi->rx_len );
977 	memcpy ( ( iscsi->rx_buffer + iscsi->rx_offset ), data, len );
978 
979 	return 0;
980 }
981 
982 /**
983  * Convert iSCSI response status to return status code
984  *
985  * @v status_class	iSCSI status class
986  * @v status_detail	iSCSI status detail
987  * @ret rc		Return status code
988  */
iscsi_status_to_rc(unsigned int status_class,unsigned int status_detail)989 static int iscsi_status_to_rc ( unsigned int status_class,
990 				unsigned int status_detail ) {
991 	switch ( status_class ) {
992 	case ISCSI_STATUS_INITIATOR_ERROR :
993 		switch ( status_detail ) {
994 		case ISCSI_STATUS_INITIATOR_ERROR_AUTHENTICATION :
995 			return -EACCES;
996 		case ISCSI_STATUS_INITIATOR_ERROR_AUTHORISATION :
997 			return -EPERM;
998 		case ISCSI_STATUS_INITIATOR_ERROR_NOT_FOUND :
999 		case ISCSI_STATUS_INITIATOR_ERROR_REMOVED :
1000 			return -ENODEV;
1001 		default :
1002 			return -ENOTSUP;
1003 		}
1004 	case ISCSI_STATUS_TARGET_ERROR :
1005 		return -EIO;
1006 	default :
1007 		return -EINVAL;
1008 	}
1009 }
1010 
1011 /**
1012  * Receive data segment of an iSCSI login response PDU
1013  *
1014  * @v iscsi		iSCSI session
1015  * @v data		Received data
1016  * @v len		Length of received data
1017  * @v remaining		Data remaining after this data
1018  * @ret rc		Return status code
1019  */
iscsi_rx_login_response(struct iscsi_session * iscsi,const void * data,size_t len,size_t remaining)1020 static int iscsi_rx_login_response ( struct iscsi_session *iscsi,
1021 				     const void *data, size_t len,
1022 				     size_t remaining ) {
1023 	struct iscsi_bhs_login_response *response
1024 		= &iscsi->rx_bhs.login_response;
1025 	int rc;
1026 
1027 	/* Buffer up the PDU data */
1028 	if ( ( rc = iscsi_rx_buffered_data ( iscsi, data, len ) ) != 0 ) {
1029 		DBGC ( iscsi, "iSCSI %p could not buffer login response: %s\n",
1030 		       iscsi, strerror ( rc ) );
1031 		return rc;
1032 	}
1033 	if ( remaining )
1034 		return 0;
1035 
1036 	/* Process string data and discard string buffer */
1037 	if ( ( rc = iscsi_handle_strings ( iscsi, iscsi->rx_buffer,
1038 					   iscsi->rx_len ) ) != 0 )
1039 		return rc;
1040 	iscsi_rx_buffered_data_done ( iscsi );
1041 
1042 	/* Check for login redirection */
1043 	if ( response->status_class == ISCSI_STATUS_REDIRECT ) {
1044 		DBGC ( iscsi, "iSCSI %p redirecting to new server\n", iscsi );
1045 		iscsi_close_connection ( iscsi, 0 );
1046 		if ( ( rc = iscsi_open_connection ( iscsi ) ) != 0 ) {
1047 			DBGC ( iscsi, "iSCSI %p could not redirect: %s\n ",
1048 			       iscsi, strerror ( rc ) );
1049 			return rc;
1050 		}
1051 		return 0;
1052 	}
1053 
1054 	/* Check for fatal errors */
1055 	if ( response->status_class != 0 ) {
1056 		DBGC ( iscsi, "iSCSI login failure: class %02x detail %02x\n",
1057 		       response->status_class, response->status_detail );
1058 		rc = iscsi_status_to_rc ( response->status_class,
1059 					  response->status_detail );
1060 		iscsi->instant_rc = rc;
1061 		return rc;
1062 	}
1063 
1064 	/* Handle login transitions */
1065 	if ( response->flags & ISCSI_LOGIN_FLAG_TRANSITION ) {
1066 		iscsi->status &= ~( ISCSI_STATUS_PHASE_MASK |
1067 				    ISCSI_STATUS_STRINGS_MASK );
1068 		switch ( response->flags & ISCSI_LOGIN_NSG_MASK ) {
1069 		case ISCSI_LOGIN_NSG_OPERATIONAL_NEGOTIATION:
1070 			iscsi->status |=
1071 				( ISCSI_STATUS_OPERATIONAL_NEGOTIATION_PHASE |
1072 				  ISCSI_STATUS_STRINGS_OPERATIONAL );
1073 			break;
1074 		case ISCSI_LOGIN_NSG_FULL_FEATURE_PHASE:
1075 			iscsi->status |= ISCSI_STATUS_FULL_FEATURE_PHASE;
1076 			break;
1077 		default:
1078 			DBGC ( iscsi, "iSCSI %p got invalid response flags "
1079 			       "%02x\n", iscsi, response->flags );
1080 			return -EIO;
1081 		}
1082 	}
1083 
1084 	/* Send next login request PDU if we haven't reached the full
1085 	 * feature phase yet.
1086 	 */
1087 	if ( ( iscsi->status & ISCSI_STATUS_PHASE_MASK ) !=
1088 	     ISCSI_STATUS_FULL_FEATURE_PHASE ) {
1089 		iscsi_start_login ( iscsi );
1090 		return 0;
1091 	}
1092 
1093 	/* Check that target authentication was successful (if required) */
1094 	if ( ( iscsi->status & ISCSI_STATUS_AUTH_REVERSE_REQUIRED ) &&
1095 	     ! ( iscsi->status & ISCSI_STATUS_AUTH_REVERSE_OK ) ) {
1096 		DBGC ( iscsi, "iSCSI %p nefarious target tried to bypass "
1097 		       "authentication\n", iscsi );
1098 		return -EPROTO;
1099 	}
1100 
1101 	/* Reset retry count */
1102 	iscsi->retry_count = 0;
1103 
1104 	/* Record TSIH for future reference */
1105 	iscsi->tsih = ntohl ( response->tsih );
1106 
1107 	/* Send the actual SCSI command */
1108 	iscsi_start_command ( iscsi );
1109 
1110 	return 0;
1111 }
1112 
1113 /****************************************************************************
1114  *
1115  * iSCSI to socket interface
1116  *
1117  */
1118 
1119 /**
1120  * Start up a new TX PDU
1121  *
1122  * @v iscsi		iSCSI session
1123  *
1124  * This initiates the process of sending a new PDU.  Only one PDU may
1125  * be in transit at any one time.
1126  */
iscsi_start_tx(struct iscsi_session * iscsi)1127 static void iscsi_start_tx ( struct iscsi_session *iscsi ) {
1128 	assert ( iscsi->tx_state == ISCSI_TX_IDLE );
1129 
1130 	/* Initialise TX BHS */
1131 	memset ( &iscsi->tx_bhs, 0, sizeof ( iscsi->tx_bhs ) );
1132 
1133 	/* Flag TX engine to start transmitting */
1134 	iscsi->tx_state = ISCSI_TX_BHS;
1135 }
1136 
1137 /**
1138  * Transmit nothing
1139  *
1140  * @v iscsi		iSCSI session
1141  * @ret rc		Return status code
1142  */
iscsi_tx_nothing(struct iscsi_session * iscsi __unused)1143 static int iscsi_tx_nothing ( struct iscsi_session *iscsi __unused ) {
1144 	return 0;
1145 }
1146 
1147 /**
1148  * Transmit basic header segment of an iSCSI PDU
1149  *
1150  * @v iscsi		iSCSI session
1151  * @ret rc		Return status code
1152  */
iscsi_tx_bhs(struct iscsi_session * iscsi)1153 static int iscsi_tx_bhs ( struct iscsi_session *iscsi ) {
1154 	return xfer_deliver_raw ( &iscsi->socket,  &iscsi->tx_bhs,
1155 				  sizeof ( iscsi->tx_bhs ) );
1156 }
1157 
1158 /**
1159  * Transmit data segment of an iSCSI PDU
1160  *
1161  * @v iscsi		iSCSI session
1162  * @ret rc		Return status code
1163  *
1164  * Handle transmission of part of a PDU data segment.  iscsi::tx_bhs
1165  * will be valid when this is called.
1166  */
iscsi_tx_data(struct iscsi_session * iscsi)1167 static int iscsi_tx_data ( struct iscsi_session *iscsi ) {
1168 	struct iscsi_bhs_common *common = &iscsi->tx_bhs.common;
1169 
1170 	switch ( common->opcode & ISCSI_OPCODE_MASK ) {
1171 	case ISCSI_OPCODE_DATA_OUT:
1172 		return iscsi_tx_data_out ( iscsi );
1173 	case ISCSI_OPCODE_LOGIN_REQUEST:
1174 		return iscsi_tx_login_request ( iscsi );
1175 	default:
1176 		/* Nothing to send in other states */
1177 		return 0;
1178 	}
1179 }
1180 
1181 /**
1182  * Transmit data padding of an iSCSI PDU
1183  *
1184  * @v iscsi		iSCSI session
1185  * @ret rc		Return status code
1186  *
1187  * Handle transmission of any data padding in a PDU data segment.
1188  * iscsi::tx_bhs will be valid when this is called.
1189  */
iscsi_tx_data_padding(struct iscsi_session * iscsi)1190 static int iscsi_tx_data_padding ( struct iscsi_session *iscsi ) {
1191 	static const char pad[] = { '\0', '\0', '\0' };
1192 	struct iscsi_bhs_common *common = &iscsi->tx_bhs.common;
1193 	size_t pad_len;
1194 
1195 	pad_len = ISCSI_DATA_PAD_LEN ( common->lengths );
1196 	if ( ! pad_len )
1197 		return 0;
1198 
1199 	return xfer_deliver_raw ( &iscsi->socket, pad, pad_len );
1200 }
1201 
1202 /**
1203  * Complete iSCSI PDU transmission
1204  *
1205  * @v iscsi		iSCSI session
1206  *
1207  * Called when a PDU has been completely transmitted and the TX state
1208  * machine is about to enter the idle state.  iscsi::tx_bhs will be
1209  * valid for the just-completed PDU when this is called.
1210  */
iscsi_tx_done(struct iscsi_session * iscsi)1211 static void iscsi_tx_done ( struct iscsi_session *iscsi ) {
1212 	struct iscsi_bhs_common *common = &iscsi->tx_bhs.common;
1213 
1214 	switch ( common->opcode & ISCSI_OPCODE_MASK ) {
1215 	case ISCSI_OPCODE_DATA_OUT:
1216 		iscsi_data_out_done ( iscsi );
1217 	case ISCSI_OPCODE_LOGIN_REQUEST:
1218 		iscsi_login_request_done ( iscsi );
1219 	default:
1220 		/* No action */
1221 		break;
1222 	}
1223 }
1224 
1225 /**
1226  * Transmit iSCSI PDU
1227  *
1228  * @v iscsi		iSCSI session
1229  * @v buf		Temporary data buffer
1230  * @v len		Length of temporary data buffer
1231  *
1232  * Constructs data to be sent for the current TX state
1233  */
iscsi_tx_step(struct process * process)1234 static void iscsi_tx_step ( struct process *process ) {
1235 	struct iscsi_session *iscsi =
1236 		container_of ( process, struct iscsi_session, process );
1237 	struct iscsi_bhs_common *common = &iscsi->tx_bhs.common;
1238 	int ( * tx ) ( struct iscsi_session *iscsi );
1239 	enum iscsi_tx_state next_state;
1240 	size_t tx_len;
1241 	int rc;
1242 
1243 	/* Select fragment to transmit */
1244 	while ( 1 ) {
1245 		switch ( iscsi->tx_state ) {
1246 		case ISCSI_TX_IDLE:
1247 			/* Stop processing */
1248 			return;
1249 		case ISCSI_TX_BHS:
1250 			tx = iscsi_tx_bhs;
1251 			tx_len = sizeof ( iscsi->tx_bhs );
1252 			next_state = ISCSI_TX_AHS;
1253 			break;
1254 		case ISCSI_TX_AHS:
1255 			tx = iscsi_tx_nothing;
1256 			tx_len = 0;
1257 			next_state = ISCSI_TX_DATA;
1258 			break;
1259 		case ISCSI_TX_DATA:
1260 			tx = iscsi_tx_data;
1261 			tx_len = ISCSI_DATA_LEN ( common->lengths );
1262 			next_state = ISCSI_TX_DATA_PADDING;
1263 			break;
1264 		case ISCSI_TX_DATA_PADDING:
1265 			tx = iscsi_tx_data_padding;
1266 			tx_len = ISCSI_DATA_PAD_LEN ( common->lengths );
1267 			next_state = ISCSI_TX_IDLE;
1268 			break;
1269 		default:
1270 			assert ( 0 );
1271 			return;
1272 		}
1273 
1274 		/* Check for window availability, if needed */
1275 		if ( tx_len && ( xfer_window ( &iscsi->socket ) == 0 ) ) {
1276 			/* Cannot transmit at this point; stop processing */
1277 			return;
1278 		}
1279 
1280 		/* Transmit data */
1281 		if ( ( rc = tx ( iscsi ) ) != 0 ) {
1282 			DBGC ( iscsi, "iSCSI %p could not transmit: %s\n",
1283 			       iscsi, strerror ( rc ) );
1284 			return;
1285 		}
1286 
1287 		/* Move to next state */
1288 		iscsi->tx_state = next_state;
1289 		if ( next_state == ISCSI_TX_IDLE )
1290 			iscsi_tx_done ( iscsi );
1291 	}
1292 }
1293 
1294 /**
1295  * Receive basic header segment of an iSCSI PDU
1296  *
1297  * @v iscsi		iSCSI session
1298  * @v data		Received data
1299  * @v len		Length of received data
1300  * @v remaining		Data remaining after this data
1301  * @ret rc		Return status code
1302  *
1303  * This fills in iscsi::rx_bhs with the data from the BHS portion of
1304  * the received PDU.
1305  */
iscsi_rx_bhs(struct iscsi_session * iscsi,const void * data,size_t len,size_t remaining __unused)1306 static int iscsi_rx_bhs ( struct iscsi_session *iscsi, const void *data,
1307 			  size_t len, size_t remaining __unused ) {
1308 	memcpy ( &iscsi->rx_bhs.bytes[iscsi->rx_offset], data, len );
1309 	if ( ( iscsi->rx_offset + len ) >= sizeof ( iscsi->rx_bhs ) ) {
1310 		DBGC2 ( iscsi, "iSCSI %p received PDU opcode %#x len %#x\n",
1311 			iscsi, iscsi->rx_bhs.common.opcode,
1312 			ISCSI_DATA_LEN ( iscsi->rx_bhs.common.lengths ) );
1313 	}
1314 	return 0;
1315 }
1316 
1317 /**
1318  * Discard portion of an iSCSI PDU.
1319  *
1320  * @v iscsi		iSCSI session
1321  * @v data		Received data
1322  * @v len		Length of received data
1323  * @v remaining		Data remaining after this data
1324  * @ret rc		Return status code
1325  *
1326  * This discards data from a portion of a received PDU.
1327  */
iscsi_rx_discard(struct iscsi_session * iscsi __unused,const void * data __unused,size_t len __unused,size_t remaining __unused)1328 static int iscsi_rx_discard ( struct iscsi_session *iscsi __unused,
1329 			      const void *data __unused, size_t len __unused,
1330 			      size_t remaining __unused ) {
1331 	/* Do nothing */
1332 	return 0;
1333 }
1334 
1335 /**
1336  * Receive data segment of an iSCSI PDU
1337  *
1338  * @v iscsi		iSCSI session
1339  * @v data		Received data
1340  * @v len		Length of received data
1341  * @v remaining		Data remaining after this data
1342  * @ret rc		Return status code
1343  *
1344  * Handle processing of part of a PDU data segment.  iscsi::rx_bhs
1345  * will be valid when this is called.
1346  */
iscsi_rx_data(struct iscsi_session * iscsi,const void * data,size_t len,size_t remaining)1347 static int iscsi_rx_data ( struct iscsi_session *iscsi, const void *data,
1348 			   size_t len, size_t remaining ) {
1349 	struct iscsi_bhs_common_response *response
1350 		= &iscsi->rx_bhs.common_response;
1351 
1352 	/* Update cmdsn and statsn */
1353 	iscsi->cmdsn = ntohl ( response->expcmdsn );
1354 	iscsi->statsn = ntohl ( response->statsn );
1355 
1356 	switch ( response->opcode & ISCSI_OPCODE_MASK ) {
1357 	case ISCSI_OPCODE_LOGIN_RESPONSE:
1358 		return iscsi_rx_login_response ( iscsi, data, len, remaining );
1359 	case ISCSI_OPCODE_SCSI_RESPONSE:
1360 		return iscsi_rx_scsi_response ( iscsi, data, len, remaining );
1361 	case ISCSI_OPCODE_DATA_IN:
1362 		return iscsi_rx_data_in ( iscsi, data, len, remaining );
1363 	case ISCSI_OPCODE_R2T:
1364 		return iscsi_rx_r2t ( iscsi, data, len, remaining );
1365 	default:
1366 		if ( remaining )
1367 			return 0;
1368 		DBGC ( iscsi, "iSCSI %p unknown opcode %02x\n", iscsi,
1369 		       response->opcode );
1370 		return -ENOTSUP;
1371 	}
1372 }
1373 
1374 /**
1375  * Receive new data
1376  *
1377  * @v socket		Transport layer interface
1378  * @v data		Received data
1379  * @v len		Length of received data
1380  * @ret rc		Return status code
1381  *
1382  * This handles received PDUs.  The receive strategy is to fill in
1383  * iscsi::rx_bhs with the contents of the BHS portion of the PDU,
1384  * throw away any AHS portion, and then process each part of the data
1385  * portion as it arrives.  The data processing routine therefore
1386  * always has a full copy of the BHS available, even for portions of
1387  * the data in different packets to the BHS.
1388  */
iscsi_socket_deliver_raw(struct xfer_interface * socket,const void * data,size_t len)1389 static int iscsi_socket_deliver_raw ( struct xfer_interface *socket,
1390 				      const void *data, size_t len ) {
1391 	struct iscsi_session *iscsi =
1392 		container_of ( socket, struct iscsi_session, socket );
1393 	struct iscsi_bhs_common *common = &iscsi->rx_bhs.common;
1394 	int ( * rx ) ( struct iscsi_session *iscsi, const void *data,
1395 		       size_t len, size_t remaining );
1396 	enum iscsi_rx_state next_state;
1397 	size_t frag_len;
1398 	size_t remaining;
1399 	int rc;
1400 
1401 	while ( 1 ) {
1402 		switch ( iscsi->rx_state ) {
1403 		case ISCSI_RX_BHS:
1404 			rx = iscsi_rx_bhs;
1405 			iscsi->rx_len = sizeof ( iscsi->rx_bhs );
1406 			next_state = ISCSI_RX_AHS;
1407 			break;
1408 		case ISCSI_RX_AHS:
1409 			rx = iscsi_rx_discard;
1410 			iscsi->rx_len = 4 * ISCSI_AHS_LEN ( common->lengths );
1411 			next_state = ISCSI_RX_DATA;
1412 			break;
1413 		case ISCSI_RX_DATA:
1414 			rx = iscsi_rx_data;
1415 			iscsi->rx_len = ISCSI_DATA_LEN ( common->lengths );
1416 			next_state = ISCSI_RX_DATA_PADDING;
1417 			break;
1418 		case ISCSI_RX_DATA_PADDING:
1419 			rx = iscsi_rx_discard;
1420 			iscsi->rx_len = ISCSI_DATA_PAD_LEN ( common->lengths );
1421 			next_state = ISCSI_RX_BHS;
1422 			break;
1423 		default:
1424 			assert ( 0 );
1425 			return -EINVAL;
1426 		}
1427 
1428 		frag_len = iscsi->rx_len - iscsi->rx_offset;
1429 		if ( frag_len > len )
1430 			frag_len = len;
1431 		remaining = iscsi->rx_len - iscsi->rx_offset - frag_len;
1432 		if ( ( rc = rx ( iscsi, data, frag_len, remaining ) ) != 0 ) {
1433 			DBGC ( iscsi, "iSCSI %p could not process received "
1434 			       "data: %s\n", iscsi, strerror ( rc ) );
1435 			iscsi_close_connection ( iscsi, rc );
1436 			iscsi_scsi_done ( iscsi, rc );
1437 			return rc;
1438 		}
1439 
1440 		iscsi->rx_offset += frag_len;
1441 		data += frag_len;
1442 		len -= frag_len;
1443 
1444 		/* If all the data for this state has not yet been
1445 		 * received, stay in this state for now.
1446 		 */
1447 		if ( iscsi->rx_offset != iscsi->rx_len )
1448 			return 0;
1449 
1450 		iscsi->rx_state = next_state;
1451 		iscsi->rx_offset = 0;
1452 	}
1453 
1454 	return 0;
1455 }
1456 
1457 /**
1458  * Handle stream connection closure
1459  *
1460  * @v socket		Transport layer interface
1461  * @v rc		Reason for close
1462  *
1463  */
iscsi_socket_close(struct xfer_interface * socket,int rc)1464 static void iscsi_socket_close ( struct xfer_interface *socket, int rc ) {
1465 	struct iscsi_session *iscsi =
1466 		container_of ( socket, struct iscsi_session, socket );
1467 
1468 	/* Even a graceful close counts as an error for iSCSI */
1469 	if ( ! rc )
1470 		rc = -ECONNRESET;
1471 
1472 	/* Close session cleanly */
1473 	iscsi_close_connection ( iscsi, rc );
1474 
1475 	/* Retry connection if within the retry limit, otherwise fail */
1476 	if ( ++iscsi->retry_count <= ISCSI_MAX_RETRIES ) {
1477 		DBGC ( iscsi, "iSCSI %p retrying connection (retry #%d)\n",
1478 		       iscsi, iscsi->retry_count );
1479 		if ( ( rc = iscsi_open_connection ( iscsi ) ) != 0 ) {
1480 			DBGC ( iscsi, "iSCSI %p could not reconnect: %s\n",
1481 			       iscsi, strerror ( rc ) );
1482 			iscsi_scsi_done ( iscsi, rc );
1483 		}
1484 	} else {
1485 		DBGC ( iscsi, "iSCSI %p retry count exceeded\n", iscsi );
1486 		iscsi->instant_rc = rc;
1487 		iscsi_scsi_done ( iscsi, rc );
1488 	}
1489 }
1490 
1491 /**
1492  * Handle redirection event
1493  *
1494  * @v socket		Transport layer interface
1495  * @v type		Location type
1496  * @v args		Remaining arguments depend upon location type
1497  * @ret rc		Return status code
1498  */
iscsi_vredirect(struct xfer_interface * socket,int type,va_list args)1499 static int iscsi_vredirect ( struct xfer_interface *socket, int type,
1500 			     va_list args ) {
1501 	struct iscsi_session *iscsi =
1502 		container_of ( socket, struct iscsi_session, socket );
1503 	va_list tmp;
1504 	struct sockaddr *peer;
1505 
1506 	/* Intercept redirects to a LOCATION_SOCKET and record the IP
1507 	 * address for the iBFT.  This is a bit of a hack, but avoids
1508 	 * inventing an ioctl()-style call to retrieve the socket
1509 	 * address from a data-xfer interface.
1510 	 */
1511 	if ( type == LOCATION_SOCKET ) {
1512 		va_copy ( tmp, args );
1513 		( void ) va_arg ( tmp, int ); /* Discard "semantics" */
1514 		peer = va_arg ( tmp, struct sockaddr * );
1515 		memcpy ( &iscsi->target_sockaddr, peer,
1516 			 sizeof ( iscsi->target_sockaddr ) );
1517 		va_end ( tmp );
1518 	}
1519 
1520 	return xfer_vreopen ( socket, type, args );
1521 }
1522 
1523 
1524 /** iSCSI socket operations */
1525 static struct xfer_interface_operations iscsi_socket_operations = {
1526 	.close		= iscsi_socket_close,
1527 	.vredirect	= iscsi_vredirect,
1528 	.window		= unlimited_xfer_window,
1529 	.alloc_iob	= default_xfer_alloc_iob,
1530 	.deliver_iob	= xfer_deliver_as_raw,
1531 	.deliver_raw	= iscsi_socket_deliver_raw,
1532 };
1533 
1534 
1535 /****************************************************************************
1536  *
1537  * iSCSI command issuing
1538  *
1539  */
1540 
1541 /**
1542  * Issue SCSI command
1543  *
1544  * @v scsi		SCSI device
1545  * @v command		SCSI command
1546  * @ret rc		Return status code
1547  */
iscsi_command(struct scsi_device * scsi,struct scsi_command * command)1548 static int iscsi_command ( struct scsi_device *scsi,
1549 			   struct scsi_command *command ) {
1550 	struct iscsi_session *iscsi =
1551 		container_of ( scsi->backend, struct iscsi_session, refcnt );
1552 	int rc;
1553 
1554 	/* Abort immediately if we have a recorded permanent failure */
1555 	if ( iscsi->instant_rc )
1556 		return iscsi->instant_rc;
1557 
1558 	/* Record SCSI command */
1559 	iscsi->command = command;
1560 
1561 	/* Issue command or open connection as appropriate */
1562 	if ( iscsi->status ) {
1563 		iscsi_start_command ( iscsi );
1564 	} else {
1565 		if ( ( rc = iscsi_open_connection ( iscsi ) ) != 0 ) {
1566 			iscsi->command = NULL;
1567 			return rc;
1568 		}
1569 	}
1570 
1571 	return 0;
1572 }
1573 
1574 /**
1575  * Shut down iSCSI interface
1576  *
1577  * @v scsi		SCSI device
1578  */
iscsi_detach(struct scsi_device * scsi)1579 void iscsi_detach ( struct scsi_device *scsi ) {
1580 	struct iscsi_session *iscsi =
1581 		container_of ( scsi->backend, struct iscsi_session, refcnt );
1582 
1583 	xfer_nullify ( &iscsi->socket );
1584 	iscsi_close_connection ( iscsi, 0 );
1585 	process_del ( &iscsi->process );
1586 	scsi->command = scsi_detached_command;
1587 	ref_put ( scsi->backend );
1588 	scsi->backend = NULL;
1589 }
1590 
1591 /****************************************************************************
1592  *
1593  * Instantiator
1594  *
1595  */
1596 
1597 /** iSCSI root path components (as per RFC4173) */
1598 enum iscsi_root_path_component {
1599 	RP_LITERAL = 0,
1600 	RP_SERVERNAME,
1601 	RP_PROTOCOL,
1602 	RP_PORT,
1603 	RP_LUN,
1604 	RP_TARGETNAME,
1605 	NUM_RP_COMPONENTS
1606 };
1607 
1608 /**
1609  * Parse iSCSI root path
1610  *
1611  * @v iscsi		iSCSI session
1612  * @v root_path		iSCSI root path (as per RFC4173)
1613  * @ret rc		Return status code
1614  */
iscsi_parse_root_path(struct iscsi_session * iscsi,const char * root_path)1615 static int iscsi_parse_root_path ( struct iscsi_session *iscsi,
1616 				   const char *root_path ) {
1617 	char rp_copy[ strlen ( root_path ) + 1 ];
1618 	char *rp_comp[NUM_RP_COMPONENTS];
1619 	char *rp = rp_copy;
1620 	int i = 0;
1621 	int rc;
1622 
1623 	/* Split root path into component parts */
1624 	strcpy ( rp_copy, root_path );
1625 	while ( 1 ) {
1626 		rp_comp[i++] = rp;
1627 		if ( i == NUM_RP_COMPONENTS )
1628 			break;
1629 		for ( ; *rp != ':' ; rp++ ) {
1630 			if ( ! *rp ) {
1631 				DBGC ( iscsi, "iSCSI %p root path \"%s\" "
1632 				       "too short\n", iscsi, root_path );
1633 				return -EINVAL;
1634 			}
1635 		}
1636 		*(rp++) = '\0';
1637 	}
1638 
1639 	/* Use root path components to configure iSCSI session */
1640 	iscsi->target_address = strdup ( rp_comp[RP_SERVERNAME] );
1641 	if ( ! iscsi->target_address )
1642 		return -ENOMEM;
1643 	iscsi->target_port = strtoul ( rp_comp[RP_PORT], NULL, 10 );
1644 	if ( ! iscsi->target_port )
1645 		iscsi->target_port = ISCSI_PORT;
1646 	if ( ( rc = scsi_parse_lun ( rp_comp[RP_LUN], &iscsi->lun ) ) != 0 ) {
1647 		DBGC ( iscsi, "iSCSI %p invalid LUN \"%s\"\n",
1648 		       iscsi, rp_comp[RP_LUN] );
1649 		return rc;
1650 	}
1651 	iscsi->target_iqn = strdup ( rp_comp[RP_TARGETNAME] );
1652 	if ( ! iscsi->target_iqn )
1653 		return -ENOMEM;
1654 
1655 	return 0;
1656 }
1657 
1658 /**
1659  * Set iSCSI authentication details
1660  *
1661  * @v iscsi		iSCSI session
1662  * @v initiator_username Initiator username, if any
1663  * @v initiator_password Initiator password, if any
1664  * @v target_username	Target username, if any
1665  * @v target_password	Target password, if any
1666  * @ret rc		Return status code
1667  */
iscsi_set_auth(struct iscsi_session * iscsi,const char * initiator_username,const char * initiator_password,const char * target_username,const char * target_password)1668 static int iscsi_set_auth ( struct iscsi_session *iscsi,
1669 			    const char *initiator_username,
1670 			    const char *initiator_password,
1671 			    const char *target_username,
1672 			    const char *target_password ) {
1673 
1674 	/* Check for initiator or target credentials */
1675 	if ( initiator_username || initiator_password ||
1676 	     target_username || target_password ) {
1677 
1678 		/* We must have at least an initiator username+password */
1679 		if ( ! ( initiator_username && initiator_password ) )
1680 			goto invalid_auth;
1681 
1682 		/* Store initiator credentials */
1683 		iscsi->initiator_username = strdup ( initiator_username );
1684 		if ( ! iscsi->initiator_username )
1685 			return -ENOMEM;
1686 		iscsi->initiator_password = strdup ( initiator_password );
1687 		if ( ! iscsi->initiator_password )
1688 			return -ENOMEM;
1689 
1690 		/* Check for target credentials */
1691 		if ( target_username || target_password ) {
1692 
1693 			/* We must have target username+password */
1694 			if ( ! ( target_username && target_password ) )
1695 				goto invalid_auth;
1696 
1697 			/* Store target credentials */
1698 			iscsi->target_username = strdup ( target_username );
1699 			if ( ! iscsi->target_username )
1700 				return -ENOMEM;
1701 			iscsi->target_password = strdup ( target_password );
1702 			if ( ! iscsi->target_password )
1703 				return -ENOMEM;
1704 		}
1705 	}
1706 
1707 	return 0;
1708 
1709  invalid_auth:
1710 	DBGC ( iscsi, "iSCSI %p invalid credentials: initiator "
1711 	       "%sname,%spw, target %sname,%spw\n", iscsi,
1712 	       ( initiator_username ? "" : "no " ),
1713 	       ( initiator_password ? "" : "no " ),
1714 	       ( target_username ? "" : "no " ),
1715 	       ( target_password ? "" : "no " ) );
1716 	return -EINVAL;
1717 }
1718 
1719 /**
1720  * Attach iSCSI interface
1721  *
1722  * @v scsi		SCSI device
1723  * @v root_path		iSCSI root path (as per RFC4173)
1724  * @ret rc		Return status code
1725  */
iscsi_attach(struct scsi_device * scsi,const char * root_path)1726 int iscsi_attach ( struct scsi_device *scsi, const char *root_path ) {
1727 	struct iscsi_session *iscsi;
1728 	int rc;
1729 
1730 	/* Allocate and initialise structure */
1731 	iscsi = zalloc ( sizeof ( *iscsi ) );
1732 	if ( ! iscsi )
1733 		return -ENOMEM;
1734 	iscsi->refcnt.free = iscsi_free;
1735 	xfer_init ( &iscsi->socket, &iscsi_socket_operations, &iscsi->refcnt );
1736 	process_init ( &iscsi->process, iscsi_tx_step, &iscsi->refcnt );
1737 
1738 	/* Parse root path */
1739 	if ( ( rc = iscsi_parse_root_path ( iscsi, root_path ) ) != 0 )
1740 		goto err;
1741 	/* Set fields not specified by root path */
1742 	if ( ( rc = iscsi_set_auth ( iscsi,
1743 				     iscsi_initiator_username,
1744 				     iscsi_initiator_password,
1745 				     iscsi_target_username,
1746 				     iscsi_target_password ) ) != 0 )
1747 		goto err;
1748 
1749 	/* Sanity checks */
1750 	if ( ! iscsi->target_address ) {
1751 		DBGC ( iscsi, "iSCSI %p does not yet support discovery\n",
1752 		       iscsi );
1753 		rc = -ENOTSUP;
1754 		goto err;
1755 	}
1756 	if ( ! iscsi->target_iqn ) {
1757 		DBGC ( iscsi, "iSCSI %p no target address supplied in %s\n",
1758 		       iscsi, root_path );
1759 		rc = -EINVAL;
1760 		goto err;
1761 	}
1762 
1763 	/* Attach parent interface, mortalise self, and return */
1764 	scsi->backend = ref_get ( &iscsi->refcnt );
1765 	scsi->command = iscsi_command;
1766 	ref_put ( &iscsi->refcnt );
1767 	return 0;
1768 
1769  err:
1770 	ref_put ( &iscsi->refcnt );
1771 	return rc;
1772 }
1773 
1774 /****************************************************************************
1775  *
1776  * Settings
1777  *
1778  */
1779 
1780 /** iSCSI initiator IQN setting */
1781 struct setting initiator_iqn_setting __setting = {
1782 	.name = "initiator-iqn",
1783 	.description = "iSCSI initiator name",
1784 	.tag = DHCP_ISCSI_INITIATOR_IQN,
1785 	.type = &setting_type_string,
1786 };
1787 
1788 /** iSCSI reverse username setting */
1789 struct setting reverse_username_setting __setting = {
1790 	.name = "reverse-username",
1791 	.description = "Reverse user name",
1792 	.tag = DHCP_EB_REVERSE_USERNAME,
1793 	.type = &setting_type_string,
1794 };
1795 
1796 /** iSCSI reverse password setting */
1797 struct setting reverse_password_setting __setting = {
1798 	.name = "reverse-password",
1799 	.description = "Reverse password",
1800 	.tag = DHCP_EB_REVERSE_PASSWORD,
1801 	.type = &setting_type_string,
1802 };
1803 
1804 /** An iSCSI string setting */
1805 struct iscsi_string_setting {
1806 	/** Setting */
1807 	struct setting *setting;
1808 	/** String to update */
1809 	char **string;
1810 	/** String prefix */
1811 	const char *prefix;
1812 };
1813 
1814 /** iSCSI string settings */
1815 static struct iscsi_string_setting iscsi_string_settings[] = {
1816 	{
1817 		.setting = &initiator_iqn_setting,
1818 		.string = &iscsi_explicit_initiator_iqn,
1819 		.prefix = "",
1820 	},
1821 	{
1822 		.setting = &username_setting,
1823 		.string = &iscsi_initiator_username,
1824 		.prefix = "",
1825 	},
1826 	{
1827 		.setting = &password_setting,
1828 		.string = &iscsi_initiator_password,
1829 		.prefix = "",
1830 	},
1831 	{
1832 		.setting = &reverse_username_setting,
1833 		.string = &iscsi_target_username,
1834 		.prefix = "",
1835 	},
1836 	{
1837 		.setting = &reverse_password_setting,
1838 		.string = &iscsi_target_password,
1839 		.prefix = "",
1840 	},
1841 	{
1842 		.setting = &hostname_setting,
1843 		.string = &iscsi_default_initiator_iqn,
1844 		.prefix = "iqn.2000-01.org.etherboot:",
1845 	},
1846 };
1847 
1848 /**
1849  * Apply iSCSI setting
1850  *
1851  * @v setting		iSCSI string setting
1852  * @ret rc		Return status code
1853  */
apply_iscsi_string_setting(struct iscsi_string_setting * setting)1854 static int apply_iscsi_string_setting ( struct iscsi_string_setting *setting ){
1855 	size_t prefix_len;
1856 	int setting_len;
1857 	size_t len;
1858 	int check_len;
1859 	char *p;
1860 
1861 	/* Free old string */
1862 	free ( *setting->string );
1863 	*setting->string = NULL;
1864 
1865 	/* Allocate new string */
1866 	prefix_len = strlen ( setting->prefix );
1867 	setting_len = fetch_setting_len ( NULL, setting->setting );
1868 	if ( setting_len < 0 ) {
1869 		/* Missing settings are not errors; leave strings as NULL */
1870 		return 0;
1871 	}
1872 	len = ( prefix_len + setting_len + 1 );
1873 	p = *setting->string = malloc ( len );
1874 	if ( ! p )
1875 		return -ENOMEM;
1876 
1877 	/* Fill new string */
1878 	strcpy ( p, setting->prefix );
1879 	check_len = fetch_string_setting ( NULL, setting->setting,
1880 					   ( p + prefix_len ),
1881 					   ( len - prefix_len ) );
1882 	assert ( check_len == setting_len );
1883 
1884 	return 0;
1885 }
1886 
1887 /**
1888  * Apply iSCSI settings
1889  *
1890  * @ret rc		Return status code
1891  */
apply_iscsi_settings(void)1892 static int apply_iscsi_settings ( void ) {
1893 	struct iscsi_string_setting *setting;
1894 	unsigned int i;
1895 	int rc;
1896 
1897 	for ( i = 0 ; i < ( sizeof ( iscsi_string_settings ) /
1898 			    sizeof ( iscsi_string_settings[0] ) ) ; i++ ) {
1899 		setting = &iscsi_string_settings[i];
1900 		if ( ( rc = apply_iscsi_string_setting ( setting ) ) != 0 ) {
1901 			DBG ( "iSCSI could not apply setting %s\n",
1902 			      setting->setting->name );
1903 			return rc;
1904 		}
1905 	}
1906 
1907 	return 0;
1908 }
1909 
1910 /** iSCSI settings applicator */
1911 struct settings_applicator iscsi_settings_applicator __settings_applicator = {
1912 	.apply = apply_iscsi_settings,
1913 };
1914 
1915 /****************************************************************************
1916  *
1917  * Initiator name
1918  *
1919  */
1920 
1921 /**
1922  * Get iSCSI initiator IQN
1923  *
1924  * @v iscsi		iSCSI session
1925  * @ret rc		Return status code
1926  */
iscsi_initiator_iqn(void)1927 const char * iscsi_initiator_iqn ( void ) {
1928 
1929 	if ( iscsi_explicit_initiator_iqn )
1930 		return iscsi_explicit_initiator_iqn;
1931 	if ( iscsi_default_initiator_iqn )
1932 		return iscsi_default_initiator_iqn;
1933 	return "iqn.2000-09.org.etherboot:UNKNOWN";
1934 }
1935