1 /*
2  * Copyright (c) 2012 Pigeon Point Systems.  All Rights Reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * Redistribution of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  *
11  * Redistribution in binary form must reproduce the above copyright
12  * notice, this list of conditions and the following disclaimer in the
13  * documentation and/or other materials provided with the distribution.
14  *
15  * Neither the name of Pigeon Point Systems nor the names of
16  * contributors may be used to endorse or promote products derived
17  * from this software without specific prior written permission.
18  *
19  * This software is provided "AS IS," without a warranty of any kind.
20  * ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
21  * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
22  * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED.
23  * PIGEON POINT SYSTEMS ("PPS") AND ITS LICENSORS SHALL NOT BE LIABLE
24  * FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
25  * OR DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.  IN NO EVENT WILL
26  * PPS OR ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA,
27  * OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR
28  * PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF
29  * LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
30  * EVEN IF PPS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
31  */
32 #define _GNU_SOURCE 1
33 
34 /* Serial Interface, Basic Mode plugin. */
35 
36 #include <stdio.h>
37 #include <fcntl.h>
38 #include <time.h>
39 #include <unistd.h>
40 #include <sys/ioctl.h>
41 #include <errno.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <ctype.h>
45 #include <sys/types.h>
46 #include <sys/stat.h>
47 #include <sys/poll.h>
48 #include <termios.h>
49 
50 #include <ipmitool/ipmi.h>
51 #include <ipmitool/ipmi_intf.h>
52 #include <ipmitool/helper.h>
53 #include <ipmitool/log.h>
54 
55 #if defined(HAVE_CONFIG_H)
56 # include <config.h>
57 #endif
58 
59 #define SERIAL_BM_MAX_MSG_SIZE	47
60 #define SERIAL_BM_MAX_RQ_SIZE	33	/* 40 - 7 */
61 #define SERIAL_BM_MAX_RS_SIZE	32	/* 40 - 8 */
62 #define	SERIAL_BM_TIMEOUT	5
63 #define SERIAL_BM_RETRY_COUNT	5
64 #define SERIAL_BM_MAX_BUFFER_SIZE 250
65 
66 #define BM_START		0xA0
67 #define BM_STOP			0xA5
68 #define BM_HANDSHAKE	0xA6
69 #define BM_ESCAPE		0xAA
70 
71 /*
72  *	IPMB message header
73  */
74 struct ipmb_msg_hdr {
75 	unsigned char rsSA;
76 	unsigned char netFn;	/* NET FN | RS LUN */
77 	unsigned char csum1;
78 	unsigned char rqSA;
79 	unsigned char rqSeq;	/* RQ SEQ | RQ LUN */
80 	unsigned char cmd;
81 	unsigned char data[0];
82 };
83 
84 /*
85  *	Send Message command request for IPMB-format
86  */
87 struct ipmi_send_message_rq {
88 	unsigned char channel;
89 	struct ipmb_msg_hdr msg;
90 };
91 
92 /*
93  *	Get Message command response for IPMB-format
94  */
95 struct ipmi_get_message_rp {
96 	unsigned char completion;
97 	unsigned char channel;
98 	unsigned char netFn;
99 	unsigned char csum1;
100 	unsigned char rsSA;
101 	unsigned char rqSeq;
102 	unsigned char cmd;
103 	unsigned char data[0];
104 };
105 
106 /*
107  *	State for the received message
108  */
109 enum {
110 	MSG_NONE,
111 	MSG_IN_PROGRESS,
112 	MSG_DONE
113 };
114 
115 /*
116  *	Message parsing context
117  */
118 struct  serial_bm_parse_ctx{
119 	int state;
120 	uint8_t * msg;
121 	size_t msg_len;
122 	size_t max_len;
123 	int escape;
124 };
125 
126 /*
127  *	Receiving context
128  */
129 struct serial_bm_recv_ctx {
130 	char buffer[SERIAL_BM_MAX_BUFFER_SIZE];
131 	size_t buffer_size;
132 	size_t max_buffer_size;
133 };
134 
135 /*
136  *	Sending context
137  */
138 struct serial_bm_request_ctx {
139 	uint8_t rsSA;
140 	uint8_t netFn;
141 	uint8_t rqSA;
142 	uint8_t rqSeq;
143 	uint8_t cmd;
144 };
145 
146 /*
147  *	Table of supported baud rates
148  */
149 static const struct {
150 	int baudinit;
151 	int baudrate;
152 } rates[] = {
153 	{ B2400, 2400 },
154 	{ B9600, 9600 },
155 	{ B19200, 19200 },
156 	{ B38400, 38400 },
157 	{ B57600, 57600 },
158 	{ B115200, 115200 },
159 	{ B230400, 230400 },
160 #ifdef B460800
161 	{ B460800, 460800 },
162 #endif
163 };
164 
165 /*
166  *	Table of special characters
167  */
168 static const struct {
169 	uint8_t character;
170 	uint8_t escape;
171 } characters[] = {
172 	{ BM_START,		0xB0 },	/* start */
173 	{ BM_STOP,		0xB5 },	/* stop */
174 	{ BM_HANDSHAKE,	0xB6 },	/* packet handshake */
175 	{ BM_ESCAPE,	0xBA },	/* data escape */
176 	{ 0x1B, 0x3B }			/* escape */
177 };
178 
179 static int is_system;
180 
181 /*
182  *	Setup serial interface
183  */
184 static int
185 serial_bm_setup(struct ipmi_intf * intf)
186 {
187 	intf->session = malloc(sizeof(struct ipmi_session));
188 	if (intf->session == NULL) {
189 		lprintf(LOG_ERR, "ipmitool: malloc failure");
190 		return -1;
191 	}
192 	memset(intf->session, 0, sizeof(struct ipmi_session));
193 
194 	/* setup default LAN maximum request and response sizes */
195 	intf->max_request_data_size = SERIAL_BM_MAX_RQ_SIZE;
196 	intf->max_response_data_size = SERIAL_BM_MAX_RS_SIZE;
197 	return 0;
198 }
199 
200 /*
201  *	Open serial interface
202  */
203 static int
204 serial_bm_open(struct ipmi_intf * intf)
205 {
206 	struct termios ti;
207 	unsigned int rate = 9600;
208 	char *p;
209 	int i;
210 
211 	if (!intf->devfile) {
212 		lprintf(LOG_ERR, "Serial device is not specified");
213 		return -1;
214 	}
215 
216 	is_system = 0;
217 
218 	/* check if baud rate is specified */
219 	if ((p = strchr(intf->devfile, ':'))) {
220 		char * pp;
221 
222 		/* separate device name from baud rate */
223 		*p++ = '\0';
224 
225 		/* check for second colon */
226 		if ((pp = strchr(p, ':'))) {
227 			/* this is needed to normally acquire baud rate */
228 			*pp++ = '\0';
229 
230 			/* check if it is a system interface */
231 			if (pp[0] == 'S' || pp[0] == 's') {
232 				is_system = 1;
233 			}
234 		}
235 
236 		if (str2uint(p, &rate)) {
237 			lprintf(LOG_ERR, "Invalid baud rate specified\n");
238 			return -1;
239 		}
240 	}
241 
242 	intf->fd = open(intf->devfile, O_RDWR | O_NONBLOCK, 0);
243 	if (intf->fd < 0) {
244 		lperror(LOG_ERR, "Could not open device at %s", intf->devfile);
245 		return -1;
246 	}
247 
248 	for (i = 0; i < sizeof(rates) / sizeof(rates[0]); i++) {
249 		if (rates[i].baudrate == rate) {
250 			break;
251 		}
252 	}
253 	if (i >= sizeof(rates) / sizeof(rates[0])) {
254 		lprintf(LOG_ERR, "Unsupported baud rate %i specified", rate);
255 		return -1;
256 	}
257 
258 	tcgetattr(intf->fd, &ti);
259 
260 	cfsetispeed(&ti, rates[i].baudinit);
261 	cfsetospeed(&ti, rates[i].baudinit);
262 
263 	/* 8N1 */
264 	ti.c_cflag &= ~PARENB;
265 	ti.c_cflag &= ~CSTOPB;
266 	ti.c_cflag &= ~CSIZE;
267 	ti.c_cflag |= CS8;
268 
269 	/* enable the receiver and set local mode */
270 	ti.c_cflag |= (CLOCAL | CREAD);
271 
272 	/* no flow control */
273 	ti.c_cflag &= ~CRTSCTS;
274 	ti.c_iflag &= ~(IGNBRK | IGNCR | INLCR | ICRNL | INPCK | ISTRIP
275 			| IXON | IXOFF | IXANY);
276 #ifdef IUCLC
277         /* Only disable uppercase-to-lowercase mapping on input for
278 	   platforms supporting the flag. */
279 	ti.c_iflag &= ~(IUCLC);
280 #endif
281 
282 
283 	ti.c_oflag &= ~(OPOST);
284 	ti.c_lflag &= ~(ICANON | ISIG | ECHO | ECHONL | NOFLSH);
285 
286 	/* set the new options for the port with flushing */
287 	tcsetattr(intf->fd, TCSAFLUSH, &ti);
288 
289 	if (intf->session->timeout == 0)
290 		intf->session->timeout = SERIAL_BM_TIMEOUT;
291 	if (intf->session->retry == 0)
292 		intf->session->retry = SERIAL_BM_RETRY_COUNT;
293 
294 	intf->opened = 1;
295 
296 	return 0;
297 }
298 
299 /*
300  *	Close serial interface
301  */
302 static void
303 serial_bm_close(struct ipmi_intf * intf)
304 {
305 	if (intf->opened) {
306 		close(intf->fd);
307 		intf->fd = -1;
308 	}
309 	ipmi_intf_session_cleanup(intf);
310 	intf->opened = 0;
311 }
312 
313 /*
314  *	Allocate sequence number for tracking
315  */
316 static uint8_t
317 serial_bm_alloc_seq(void)
318 {
319 	static uint8_t seq = 0;
320 	if (++seq == 64) {
321 		seq = 0;
322 	}
323 	return seq;
324 }
325 
326 /*
327  *	Flush the buffers
328  */
329 static int
330 serial_bm_flush(struct ipmi_intf * intf)
331 {
332 #if defined(TCFLSH)
333     return ioctl(intf->fd, TCFLSH, TCIOFLUSH);
334 #elif defined(TIOCFLUSH)
335     return ioctl(intf->fd, TIOCFLUSH);
336 #else
337 #   error "unsupported platform, missing flush support (TCFLSH/TIOCFLUSH)"
338 #endif
339 }
340 
341 /*
342  *	Return escaped character for the given one
343  */
344 static inline uint8_t
345 serial_bm_get_escaped_char(uint8_t c)
346 {
347 	int i;
348 
349 	for (i = 0; i < 5; i++) {
350 		if (characters[i].character == c) {
351 			return characters[i].escape;
352 		}
353 	}
354 
355 	return c;
356 }
357 
358 /*
359  *	Return unescaped character for the given one
360  */
361 static inline uint8_t
362 serial_bm_get_unescaped_char(uint8_t c)
363 {
364 	int i;
365 
366 	for (i = 0; i < 5; i++) {
367 		if (characters[i].escape == c) {
368 			return characters[i].character;
369 		}
370 	}
371 
372 	return c;
373 }
374 
375 /*
376  *	Send message to serial port
377  */
378 static int
379 serial_bm_send_msg(struct ipmi_intf * intf, uint8_t * msg, int msg_len)
380 {
381 	int i, size, tmp = 0;
382 	uint8_t * buf, * data;
383 
384 	if (verbose > 3) {
385 		fprintf(stderr, "Sending request:\n");
386 		fprintf(stderr, "  rsSA         = 0x%x\n", msg[0]);
387 		fprintf(stderr, "  NetFN/rsLUN  = 0x%x\n", msg[1]);
388 		fprintf(stderr, "  rqSA         = 0x%x\n", msg[3]);
389 		fprintf(stderr, "  rqSeq/rqLUN  = 0x%x\n", msg[4]);
390 		fprintf(stderr, "  cmd          = 0x%x\n", msg[5]);
391 		if (msg_len > 7) {
392 			fprintf(stderr, "  data_len     = %d\n", msg_len - 7);
393 			fprintf(stderr, "  data         = %s\n",
394 					buf2str(msg + 6, msg_len - 7));
395 		}
396 	}
397 
398 	if (verbose > 4) {
399 		fprintf(stderr, "Message data:\n");
400 		fprintf(stderr, " %s\n", buf2str(msg, msg_len));
401 	}
402 
403 	/* calculate escaped characters number */
404 	for (i = 0; i < msg_len; i++) {
405 		if (serial_bm_get_escaped_char(msg[i]) != msg[i]) {
406 			tmp++;
407 		}
408 	}
409 
410 	/* calculate required buffer size */
411 	size = msg_len + tmp + 2;
412 
413 	/* allocate buffer for output data */
414 	buf = data = (uint8_t *) alloca(size);
415 
416 	if (!buf) {
417 		lperror(LOG_ERR, "ipmitool: alloca error");
418 		return -1;
419 	}
420 
421 	/* start character */
422 	*buf++ = 0xA0;
423 
424 	for (i = 0; i < msg_len; i++) {
425 		tmp = serial_bm_get_escaped_char(msg[i]);
426 		if (tmp != msg[i]) {
427 			*buf++ = 0xAA;
428 		}
429 
430 		*buf++ = tmp;
431 	}
432 
433 	/* stop character */
434 	*buf++ = 0xA5;
435 
436 	if (verbose > 5) {
437 		fprintf(stderr, "Sent serial data:\n %s\n", buf2str(data, size));
438 	}
439 
440 	/* write data to serial port */
441 	tmp = write(intf->fd, data, size);
442 	if (tmp <= 0) {
443 		lperror(LOG_ERR, "ipmitool: write error");
444 		return -1;
445 	}
446 
447 	return 0;
448 }
449 
450 /*
451  *	This function waits for incoming data
452  */
453 static int
454 serial_bm_wait_for_data(struct ipmi_intf * intf)
455 {
456 	int n;
457 	struct pollfd pfd;
458 
459 	pfd.fd = intf->fd;
460 	pfd.events = POLLIN;
461 	pfd.revents = 0;
462 
463 	n = poll(&pfd, 1, intf->session->timeout*1000);
464 	if (n < 0) {
465 		lperror(LOG_ERR, "Poll for serial data failed");
466 		return -1;
467 	} else if (!n) {
468 		return -1;
469 	}
470 	return 0;
471 }
472 
473 /*
474  *	This function parses incoming data in basic mode format to IPMB message
475  */
476 static int
477 serial_bm_parse_buffer(const uint8_t * data, int data_len,
478 		struct serial_bm_parse_ctx * ctx)
479 {
480 	int i, tmp;
481 
482 	for (i = 0; i < data_len; i++) {
483 		/* check for start of new message */
484 		if (data[i] == BM_START) {
485 			ctx->state = MSG_IN_PROGRESS;
486 			ctx->escape = 0;
487 			ctx->msg_len = 0;
488 		/* check if message is not started */
489 		} else if (ctx->state != MSG_IN_PROGRESS) {
490 			/* skip character */
491 			continue;
492 		/* continue escape sequence */
493 		} else	if (ctx->escape) {
494 			/* get original character */
495 			tmp = serial_bm_get_unescaped_char(data[i]);
496 
497 			/* check if not special character */
498 			if (tmp == data[i]) {
499 				lprintf(LOG_ERR, "ipmitool: bad response");
500 				/* reset message state */
501 				ctx->state = MSG_NONE;
502 				continue;
503 			}
504 
505 			/* check message length */
506 			if (ctx->msg_len >= ctx->max_len) {
507 				lprintf(LOG_ERR, "ipmitool: response is too long");
508 				/* reset message state */
509 				ctx->state = MSG_NONE;
510 				continue;
511 			}
512 
513 			/* add parsed character */
514 			ctx->msg[ctx->msg_len++] = tmp;
515 
516 			/* clear escape flag */
517 			ctx->escape = 0;
518 		/* check for escape character */
519 		} else if (data[i] == BM_ESCAPE) {
520 			ctx->escape = 1;
521 			continue;
522 		/* check for stop character */
523 		} else if (data[i] == BM_STOP) {
524 			ctx->state = MSG_DONE;
525 			return i + 1;
526 		/* check for packet handshake character */
527 		} else if (data[i] == BM_HANDSHAKE) {
528 			/* just skip it */
529 			continue;
530 		} else {
531 			/* check message length */
532 			if (ctx->msg_len >= ctx->max_len) {
533 				lprintf(LOG_ERR, "ipmitool: response is too long");
534 				return -1;
535 			}
536 
537 			/* add parsed character */
538 			ctx->msg[ctx->msg_len++] = data[i];
539 		}
540 	}
541 
542 	/* return number of parsed characters */
543 	return i;
544 }
545 
546 /*
547  *	Read and parse data from serial port
548  */
549 static int
550 serial_bm_recv_msg(struct ipmi_intf * intf,
551 		struct serial_bm_recv_ctx * recv_ctx,
552 		uint8_t * msg_data, size_t msg_len)
553 {
554 	struct serial_bm_parse_ctx parse_ctx;
555 	int rv;
556 
557 	parse_ctx.state = MSG_NONE;
558 	parse_ctx.msg = msg_data;
559 	parse_ctx.max_len = msg_len;
560 
561 	do {
562 		/* wait for data in the port */
563 		if (serial_bm_wait_for_data(intf)) {
564 			return 0;
565 		}
566 
567 		/* read data into buffer */
568 		rv = read(intf->fd, recv_ctx->buffer + recv_ctx->buffer_size,
569 				recv_ctx->max_buffer_size - recv_ctx->buffer_size);
570 
571 		if (rv < 0) {
572 			lperror(LOG_ERR, "ipmitool: read error");
573 			return -1;
574 		}
575 
576 		if (verbose > 5) {
577 			fprintf(stderr, "Received serial data:\n %s\n",
578 					buf2str(recv_ctx->buffer + recv_ctx->buffer_size, rv));
579 		}
580 
581 		/* increment buffer size */
582 		recv_ctx->buffer_size += rv;
583 
584 		/* parse buffer */
585 		rv = serial_bm_parse_buffer(recv_ctx->buffer,
586 				recv_ctx->buffer_size, &parse_ctx);
587 
588 		if (rv < recv_ctx->buffer_size) {
589 			/* move non-parsed part of the buffer to the beginning */
590 			memmove(recv_ctx->buffer, recv_ctx->buffer + rv,
591 					recv_ctx->buffer_size - rv);
592 		}
593 
594 		/* decrement buffer size */
595 		recv_ctx->buffer_size -= rv;
596 	} while (parse_ctx.state != MSG_DONE);
597 
598 	if (verbose > 4) {
599 		printf("Received message:\n %s\n",
600 				buf2str(msg_data, parse_ctx.msg_len));
601 	}
602 
603 	/* received a message */
604 	return parse_ctx.msg_len;
605 }
606 
607 /*
608  *	Build IPMB message to be transmitted
609  */
610 static int
611 serial_bm_build_msg(const struct ipmi_intf * intf,
612 		const struct ipmi_rq * req, uint8_t * msg, size_t max_len,
613 		struct serial_bm_request_ctx * ctx, int * msg_len
614 		)
615 {
616 	uint8_t * data = msg, seq;
617 	struct ipmb_msg_hdr * hdr = (struct ipmb_msg_hdr *) msg;
618 	struct ipmi_send_message_rq * inner_rq = NULL, * outer_rq = NULL;
619 	int bridging_level;
620 
621 	/* acquire bridging level */
622 	if (intf->target_addr && intf->target_addr != intf->my_addr) {
623 		if (intf->transit_addr != 0) {
624 			bridging_level = 2;
625 		} else {
626 			bridging_level = 1;
627 		}
628 	} else {
629 		bridging_level = 0;
630 	}
631 
632 	/* check overall packet length */
633 	if(req->msg.data_len + 7 + bridging_level * 8 > max_len) {
634 		lprintf(LOG_ERR, "ipmitool: Message data is too long");
635 		return -1;
636 	}
637 
638 	/* allocate new sequence number */
639 	seq = serial_bm_alloc_seq() << 2;
640 
641 	if (bridging_level) {
642 		/* compose send message request */
643 		hdr->netFn = 0x18;
644 		hdr->cmd = 0x34;
645 
646 		/* set pointer to send message request data */
647 		outer_rq = (struct ipmi_send_message_rq *) (hdr + 1);
648 
649 		/* compose the outer send message request */
650 		if (bridging_level == 2) {
651 			outer_rq->channel = intf->transit_channel | 0x40;
652 			outer_rq->msg.rsSA = intf->transit_addr;
653 			outer_rq->msg.netFn = 0x18;
654 			outer_rq->msg.csum1 = -(outer_rq->msg.rsSA + outer_rq->msg.netFn);
655 			outer_rq->msg.rqSA = intf->my_addr;
656 			outer_rq->msg.rqSeq = seq;
657 			outer_rq->msg.cmd = 0x34;
658 
659 			/* inner send message request is further */
660 			inner_rq = (outer_rq + 1);
661 		} else {
662 			/* there is only outer send message reuest */
663 			inner_rq = outer_rq;
664 		}
665 
666 		/* compose the inner send message request */
667 		inner_rq->channel = intf->target_channel | 0x40;
668 		inner_rq->msg.rsSA = intf->target_addr;
669 		inner_rq->msg.netFn = (req->msg.netfn << 2) | req->msg.lun;
670 		inner_rq->msg.csum1 = -(inner_rq->msg.rsSA + inner_rq->msg.netFn);
671 		inner_rq->msg.rqSA = intf->my_addr;
672 		inner_rq->msg.rqSeq = seq;
673 		inner_rq->msg.cmd = req->msg.cmd;
674 
675 		/* check if interface is the system one */
676 		if (is_system) {
677 			/* need response to LUN 2 */
678 			outer_rq->msg.rqSeq |= 2;
679 
680 			/* do not track response */
681 			outer_rq->channel &= ~0x40;
682 
683 			/* restore BMC SA if bridging not to primary IPMB channel */
684 			if (outer_rq->channel) {
685 				outer_rq->msg.rqSA = IPMI_BMC_SLAVE_ADDR;
686 			}
687 		}
688 
689 		/* fill-in the second context */
690 		ctx[1].rsSA = outer_rq->msg.rsSA;
691 		ctx[1].netFn = outer_rq->msg.netFn;
692 		ctx[1].rqSA = outer_rq->msg.rqSA;
693 		ctx[1].rqSeq = outer_rq->msg.rqSeq;
694 		ctx[1].cmd = outer_rq->msg.cmd;
695 
696 		/* move write pointer */
697 		msg = (uint8_t *)(inner_rq + 1);
698 	} else {
699 		/* compose direct request */
700 		hdr->netFn = (req->msg.netfn << 2) | req->msg.lun;
701 		hdr->cmd = req->msg.cmd;
702 
703 		/* move write pointer */
704 		msg = (uint8_t *)(hdr + 1);
705 	}
706 
707 	/* fill-in the rest header fields */
708 	hdr->rsSA = IPMI_BMC_SLAVE_ADDR;
709 	hdr->csum1 = -(hdr->rsSA + hdr->netFn);
710 	hdr->rqSA = IPMI_REMOTE_SWID;
711 	hdr->rqSeq = seq;
712 
713 	/* fill-in the first context */
714 	ctx[0].rsSA = hdr->rsSA;
715 	ctx[0].netFn = hdr->netFn;
716 	ctx[0].rqSA = hdr->rqSA;
717 	ctx[0].rqSeq = hdr->rqSeq;
718 	ctx[0].cmd = hdr->cmd;
719 
720 	/* write request data */
721 	memcpy(msg, req->msg.data, req->msg.data_len);
722 
723 	/* move write pointer */
724 	msg += req->msg.data_len;
725 
726 	if (bridging_level) {
727 		/* write inner message checksum */
728 		*msg++ = ipmi_csum(&inner_rq->msg.rqSA, req->msg.data_len + 3);
729 
730 		/* check for double bridging */
731 		if (bridging_level == 2) {
732 			/* write outer message checksum */
733 			*msg++ = ipmi_csum(&outer_rq->msg.rqSA, 4);
734 		}
735 
736 		/* write overall message checksum */
737 		*msg++ = ipmi_csum(&hdr->rqSA, 4);
738 	} else {
739 		/* write overall message checksum */
740 		*msg++ = ipmi_csum(&hdr->rqSA, req->msg.data_len + 3);
741 	}
742 
743 	/* save message length */
744 	*msg_len = msg - data;
745 
746 	/* return bridging level */
747 	return bridging_level;
748 }
749 
750 /*
751  *	Wait for request response
752  */
753 static int
754 serial_bm_wait_response(struct ipmi_intf * intf,
755 		struct serial_bm_request_ctx * req_ctx, struct serial_bm_recv_ctx * read_ctx,
756 		uint8_t * msg, size_t max_len)
757 {
758 	struct ipmb_msg_hdr * hdr = (struct ipmb_msg_hdr *) msg;
759 	int msg_len, netFn, rqSeq;
760 
761 	/* receive and match message */
762 	while ((msg_len = serial_bm_recv_msg(intf, read_ctx, msg, max_len)) > 0) {
763 		/* validate message size */
764 		if (msg_len < 8) {
765 			lprintf(LOG_ERR, "ipmitool: response is too short");
766 			continue;
767 		}
768 
769 		/* validate checksum 1 */
770 		if (ipmi_csum(msg, 3)) {
771 			lprintf(LOG_ERR, "ipmitool: bad checksum 1");
772 			continue;
773 		}
774 
775 		/* validate checksum 2 */
776 		if (ipmi_csum(msg + 3, msg_len - 3)) {
777 			lprintf(LOG_ERR, "ipmitool: bad checksum 2");
778 			continue;
779 		}
780 
781 		/* swap requester and responder LUNs */
782 		netFn = ((req_ctx->netFn|4) & ~3) | (req_ctx->rqSeq & 3);
783 		rqSeq = (req_ctx->rqSeq & ~3) | (req_ctx->netFn & 3);
784 
785 		/* check for the waited response */
786 		if (hdr->rsSA == req_ctx->rqSA
787 				&& hdr->netFn == netFn
788 				&& hdr->rqSA == req_ctx->rsSA
789 				&& hdr->rqSeq == rqSeq
790 				&& hdr->cmd == req_ctx->cmd) {
791 			/* check if something new has been parsed */
792 			if (verbose > 3) {
793 				fprintf(stderr, "Got response:\n");
794 				fprintf(stderr, "  rsSA            = 0x%x\n", msg[0]);
795 				fprintf(stderr, "  NetFN/rsLUN     = 0x%x\n", msg[1]);
796 				fprintf(stderr, "  rqSA            = 0x%x\n", msg[3]);
797 				fprintf(stderr, "  rqSeq/rqLUN     = 0x%x\n", msg[4]);
798 				fprintf(stderr, "  cmd             = 0x%x\n", msg[5]);
799 				fprintf(stderr, "  completion code = 0x%x\n", msg[6]);
800 				if (msg_len > 8) {
801 					fprintf(stderr, "  data_len        = %d\n", msg_len - 8);
802 					fprintf(stderr, "  data            = %s\n",
803 							buf2str(msg + 7, msg_len - 8));
804 				}
805 			}
806 
807 			/* copy only completion and response data */
808 			memmove(msg, hdr + 1, msg_len - sizeof (*hdr) - 1);
809 
810 			/* update message length */
811 			msg_len -= sizeof (*hdr) + 1;
812 
813 			/* the waited one */
814 			break;
815 		}
816 	}
817 
818 	return msg_len;
819 }
820 
821 /*
822  *	Get message from receive message queue
823  */
824 static int
825 serial_bm_get_message(struct ipmi_intf * intf,
826 		struct serial_bm_request_ctx * req_ctx,
827 		struct serial_bm_recv_ctx * read_ctx,
828 		uint8_t * msg, size_t max_len)
829 {
830 	uint8_t data[SERIAL_BM_MAX_MSG_SIZE];
831 	struct serial_bm_request_ctx tmp_ctx;
832 	struct ipmi_get_message_rp * rp = (struct ipmi_get_message_rp *) data;
833 	struct ipmb_msg_hdr * hdr = (struct ipmb_msg_hdr *) data;
834 	clock_t start, tm;
835 	int rv, netFn, rqSeq;
836 
837 	start = clock();
838 
839 	do {
840 		/* fill-in request context */
841 		tmp_ctx.rsSA = IPMI_BMC_SLAVE_ADDR;
842 		tmp_ctx.netFn = 0x18;
843 		tmp_ctx.rqSA = IPMI_REMOTE_SWID;
844 		tmp_ctx.rqSeq = serial_bm_alloc_seq() << 2;
845 		tmp_ctx.cmd = 0x33;
846 
847 		/* fill-in request data */
848 		hdr->rsSA = tmp_ctx.rsSA;
849 		hdr->netFn = tmp_ctx.netFn;
850 		hdr->csum1 = ipmi_csum(data, 2);
851 		hdr->rqSA = tmp_ctx.rqSA;
852 		hdr->rqSeq = tmp_ctx.rqSeq;
853 		hdr->cmd = tmp_ctx.cmd;
854 		hdr->data[0] = ipmi_csum(&hdr->rqSA, 3);
855 
856 		/* send request */
857 		serial_bm_flush(intf);
858 		serial_bm_send_msg(intf, data, 7);
859 
860 		/* wait for response */
861 		rv = serial_bm_wait_response(intf, &tmp_ctx, read_ctx,
862 				data, sizeof (data));
863 
864 		/* check for IO error or timeout */
865 		if (rv <= 0) {
866 			return rv;
867 		}
868 
869 		/* check completion code */
870 		if (rp->completion == 0) {
871 			/* swap requester and responder LUNs */
872 			netFn = ((req_ctx->netFn|4) & ~3) | (req_ctx->rqSeq & 3);
873 			rqSeq = (req_ctx->rqSeq & ~3) | (req_ctx->netFn & 3);
874 
875 			/* check for the waited response */
876 			if (rp->netFn == netFn
877 					&& rp->rsSA == req_ctx->rsSA
878 					&& rp->rqSeq == rqSeq
879 					&& rp->cmd == req_ctx->cmd) {
880 				/* copy the rest of message */
881 				memcpy(msg, rp->data, rv - sizeof (*rp) - 1);
882 				return rv - sizeof (*rp) - 1;
883 			}
884 		} else if (rp->completion != 0x80) {
885 			return 0;
886 		}
887 
888 		tm = clock() - start;
889 
890 		tm /= CLOCKS_PER_SEC;
891 	} while (tm < intf->session->timeout);
892 
893 	return 0;
894 }
895 
896 static struct ipmi_rs *
897 serial_bm_send_request(struct ipmi_intf * intf, struct ipmi_rq * req)
898 {
899 	static struct ipmi_rs rsp;
900 	uint8_t msg[SERIAL_BM_MAX_MSG_SIZE], * resp = msg;
901 	struct serial_bm_request_ctx req_ctx[3];
902 	struct serial_bm_recv_ctx read_ctx;
903 	int retry, rv, msg_len, bridging_level;
904 
905 	if (!intf->opened && intf->open && intf->open(intf) < 0) {
906 		return NULL;
907 	}
908 
909 	/* reset receive context */
910 	read_ctx.buffer_size = 0;
911 	read_ctx.max_buffer_size = SERIAL_BM_MAX_BUFFER_SIZE;
912 
913 	/* Send the message and receive the answer */
914 	for (retry = 0; retry < intf->session->retry; retry++) {
915 		/* build output message */
916 		bridging_level = serial_bm_build_msg(intf, req, msg,
917 				sizeof (msg), req_ctx, &msg_len);
918 		if (msg_len < 0) {
919 			return NULL;
920 		}
921 
922 		/* send request */
923 		serial_bm_flush(intf);
924 		serial_bm_send_msg(intf, msg, msg_len);
925 
926 		/* wait for response */
927 		rv = serial_bm_wait_response(intf, &req_ctx[0],
928 				&read_ctx, msg, sizeof (msg));
929 
930 		/* check for IO error */
931 		if (rv < 0) {
932 			return NULL;
933 		}
934 
935 		/* check for timeout */
936 		if (rv == 0) {
937 			continue;
938 		}
939 
940 		/* check for bridging */
941 		if (bridging_level && msg[0] == 0) {
942 			/* in the case of payload interface we check receive message queue */
943 			if (is_system) {
944 				/* check message flags */
945 				rv = serial_bm_get_message(intf, &req_ctx[1],
946 						&read_ctx, msg, sizeof (msg));
947 
948 				/* check for IO error */
949 				if (rv < 0) {
950 					return NULL;
951 				}
952 
953 				/* check for timeout */
954 				if (rv == 0) {
955 					continue;
956 				}
957 			/* check if response for inner request is not encapsulated */
958 			} else if (rv == 1) {
959 				/* wait for response for inner request */
960 				rv = serial_bm_wait_response(intf, &req_ctx[0],
961 						&read_ctx, msg, sizeof (msg));
962 
963 				/* check for IO error */
964 				if (rv < 0) {
965 					return NULL;
966 				}
967 
968 				/* check for timeout */
969 				if (rv == 0) {
970 					continue;
971 				}
972 			} else {
973 				/* skip outer level header */
974 				resp = msg + 7;
975 				/* decrement response size */
976 				rv -= 8;
977 			}
978 
979 			/* check response size */
980 			if (resp[0] == 0 && bridging_level == 2 && rv < 8) {
981 				lprintf(LOG_ERR, "ipmitool: Message response is too short");
982 				/* invalid message length */
983 				return NULL;
984 			}
985 		}
986 
987 		/* check for double bridging */
988 		if (bridging_level == 2 && resp[0] == 0) {
989 			/* get completion code */
990 			rsp.ccode = resp[7];
991 			rsp.data_len = rv - 9;
992 			memcpy(rsp.data, resp + 8, rsp.data_len);
993 		} else {
994 			rsp.ccode = resp[0];
995 			rsp.data_len = rv - 1;
996 			memcpy(rsp.data, resp + 1, rsp.data_len);
997 		}
998 
999 		/* return response */
1000 		return &rsp;
1001 	}
1002 
1003 	/* no valid response */
1004 	return NULL;
1005 }
1006 
1007 int
1008 serial_bm_set_my_addr(struct ipmi_intf * intf, uint8_t addr)
1009 {
1010 	intf->my_addr = addr;
1011 	return 0;
1012 }
1013 
1014 /*
1015  *	Serial BM interface
1016  */
1017 struct ipmi_intf ipmi_serial_bm_intf = {
1018 	.name = "serial-basic",
1019 	.desc = "Serial Interface, Basic Mode",
1020 	.setup = serial_bm_setup,
1021 	.open = serial_bm_open,
1022 	.close = serial_bm_close,
1023 	.sendrecv = serial_bm_send_request,
1024 	.set_my_addr = serial_bm_set_my_addr
1025 };
1026