Test

xymodem.c

@@ -0,0 +1,597 @@
+/*
+ * Handles the X-Modem, Y-Modem and Y-Modem/G protocols
+ *
+ * Copyright (C) 2008 Robert Jarzmik
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * This file provides functions to receive X-Modem or Y-Modem(/G) protocols.
+ *
+ * References:
+ *   *-Modem: http://www.techfest.com/hardware/modem/xymodem.htm
+ *            XMODEM/YMODEM PROTOCOL REFERENCE, Chuck Forsberg
+ */
+#include <common.h>
+#include <xfuncs.h>
+#include <errno.h>
+#include <crc.h>
+#include <clock.h>
+#include <console.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <fs.h>
+#include <kfifo.h>
+#include <linux/byteorder/generic.h>
+#include <xymodem.h>
+
+#define xy_dbg(fmt, args...)
+
+/* Values magic to the protocol */
+#define SOH 0x01
+#define STX 0x02
+#define EOT 0x04
+#define ACK 0x06
+#define BSP 0x08
+#define NAK 0x15
+#define CAN 0x18
+
+#define PROTO_XMODEM	0
+#define PROTO_YMODEM	1
+#define PROTO_YMODEM_G	2
+#define MAX_PROTOS	3
+
+#define CRC_NONE	0	/* No CRC checking */
+#define CRC_ADD8	1	/* Add of all data bytes */
+#define CRC_CRC16	2	/* CCCIT CRC16 */
+#define MAX_CRCS	3
+
+#define MAX_RETRIES		10
+#define MAX_RETRIES_WITH_CRC	5
+#define TIMEOUT_READ		(1 * SECOND)
+#define TIMEOUT_FLUSH		(1 * SECOND)
+#define MAX_CAN_BEFORE_ABORT	5
+#define INPUT_FIFO_SIZE		(4 * 1024)	/* Should always be > 1029 */
+
+enum proto_state {
+	PROTO_STATE_GET_FILENAME = 0,
+	PROTO_STATE_NEGOCIATE_CRC,
+	PROTO_STATE_RECEIVE_BODY,
+	PROTO_STATE_FINISHED_FILE,
+	PROTO_STATE_FINISHED_XFER,
+};
+
+/**
+ * struct xyz_ctxt - context of a x/y modem (g) transfer
+ *
+ * @cdev: console device to support *MODEM transfer
+ * @fifo: fifo to buffer input from serial line
+ *        This is necessary for low hardware FIFOs buffers as UARTs.
+ * @mode: protocol (XMODEM, YMODEM or YMODEM/G)
+ * @crc_mode: CRC_NONE, CRC_ADD8 or CRC_CRC16
+ * @state: protocol state (as in "state machine")
+ * @buf: buffer to store the last tranfered buffer chunk
+ * @filename : filename transmitted by sender (YMODEM* only)
+ * @fd : file descriptor of the current stored file
+ * @file_len: length declared by sender (YMODEM* only)
+ * @nb_received: number of data bytes received since session open
+ *               (this doesn't count resends)
+ * @total_SOH: number of SOH frames received (128 bytes chunks)
+ * @total_STX: number of STX frames received (1024 bytes chunks)
+ * @total_CAN: nubmer of CAN frames received (cancel frames)
+ */
+struct xyz_ctxt {
+	struct console_device *cdev;
+	struct kfifo *fifo;
+	int mode;
+	int crc_mode;
+	enum proto_state state;
+	char filename[1024];
+	int fd;
+	int file_len;
+	int nb_received;
+	int next_blk;
+	int total_SOH, total_STX, total_CAN, total_retries;
+};
+
+/**
+ * struct xy_block - one unitary block of x/y modem (g) transfer
+ *
+ * @buf: data buffer
+ * @len: length of data buffer (can only be 128 or 1024)
+ * @seq: block sequence number (as in X/Y/YG MODEM protocol)
+ */
+struct xy_block {
+	unsigned char buf[1024];
+	int len;
+	int seq;
+};
+
+/*
+ * For XMODEM/YMODEM, always try to use the CRC16 versions, called also
+ * XMODEM/CRC and YMODEM.
+ * Only fallback to additive CRC (8 bits) if sender doesn't cope with CRC16.
+ */
+static const char invite_filename_hdr[MAX_PROTOS][MAX_CRCS] = {
+	{ 0, NAK, 'C' },	/* XMODEM */
+	{ 0, NAK, 'C' },	/* YMODEM */
+	{ 0, 'G', 'G' },	/* YMODEM-G */
+};
+
+static const char invite_file_body[MAX_PROTOS][MAX_CRCS] = {
+	{ 0, NAK, 'C' },	/* XMODEM */
+	{ 0, NAK, 'C' },	/* YMODEM */
+	{ 0, 'G', 'G' },	/* YMODEM-G */
+};
+
+static const char block_ack[MAX_PROTOS][MAX_CRCS] = {
+	{ 0, ACK, ACK },	/* XMODEM */
+	{ 0, ACK, ACK },	/* YMODEM */
+	{ 0, 0, 0 },		/* YMODEM-G */
+};
+
+static const char block_nack[MAX_PROTOS][MAX_CRCS] = {
+	{ 0, NAK, NAK },	/* XMODEM */
+	{ 0, NAK, NAK },	/* YMODEM */
+	{ 0, 0, 0 },		/* YMODEM-G */
+};
+
+static int input_fifo_fill(struct console_device *cdev, struct kfifo *fifo)
+{
+	while (cdev->tstc(cdev) && kfifo_len(fifo) < INPUT_FIFO_SIZE)
+		kfifo_putc(fifo, (unsigned char)(cdev->getc(cdev)));
+	return kfifo_len(fifo);
+}
+
+/*
+ * This function is optimized to :
+ * - maximize throughput (ie. read as much as is available in lower layer fifo)
+ * - minimize latencies (no delay or wait timeout if data available)
+ * - have a timeout
+ * This is why standard getc() is not used, and input_fifo_fill() exists.
+ */
+static int xy_gets(struct console_device *cdev, struct kfifo *fifo,
+		      unsigned char *buf, int len, uint64_t timeout)
+{
+	int i, rc;
+	uint64_t start = get_time_ns();
+
+	for (i = 0, rc = 0; rc >= 0 && i < len; ) {
+		if (is_timeout(start, timeout)) {
+			rc = -ETIMEDOUT;
+			continue;
+		}
+		if (input_fifo_fill(cdev, fifo))
+			kfifo_getc(fifo, &buf[i++]);
+	}
+
+	return rc < 0 ? rc : i;
+}
+
+static void xy_putc(struct console_device *cdev, unsigned char c)
+{
+	cdev->putc(cdev, c);
+}
+
+static void xy_flush(struct console_device *cdev, struct kfifo *fifo)
+{
+	uint64_t start;
+
+	start = get_time_ns();
+	while (cdev->tstc(cdev) &&
+	       !is_timeout(start, TIMEOUT_FLUSH))
+		cdev->getc(cdev);
+	mdelay(250);
+	while (cdev->tstc(cdev) &&
+	       !is_timeout(start, TIMEOUT_FLUSH))
+		cdev->getc(cdev);
+	kfifo_reset(fifo);
+}
+
+static int is_xmodem(struct xyz_ctxt *proto)
+{
+	return proto->mode == PROTO_XMODEM;
+}
+
+static void xy_block_ack(struct xyz_ctxt *proto)
+{
+	unsigned char c = block_ack[proto->mode][proto->crc_mode];
+
+	if (c)
+		xy_putc(proto->cdev, c);
+}
+
+static void xy_block_nack(struct xyz_ctxt *proto)
+{
+	unsigned char c = block_nack[proto->mode][proto->crc_mode];
+
+	if (c)
+		xy_putc(proto->cdev, c);
+	proto->total_retries++;
+}
+
+static int check_crc(unsigned char *buf, int len, int crc, int crc_mode)
+{
+	unsigned char crc8 = 0;
+	uint16_t crc16;
+	int i;
+
+	switch (crc_mode) {
+	case CRC_ADD8:
+		for (i = 0; i < len; i++)
+			crc8 += buf[i];
+		return crc8 == crc ? 0 : -EBADMSG;
+	case CRC_CRC16:
+		crc16 = cyg_crc16(buf, len);
+		xy_dbg("crc16: received = %x, calculated=%x\n", crc, crc16);
+		return crc16 == crc ? 0 : -EBADMSG;
+	case CRC_NONE:
+		return 0;
+	default:
+		return -EBADMSG;
+	}
+}
+
+/**
+ * xy_read_block - read a X-Modem or Y-Modem(G) block
+ * @proto: protocol control structure
+ * @blk: block read
+ * @timeout: maximal time to get data
+ *
+ * This is the pivotal function for block receptions. It attempts to receive one
+ * block, ie. one 128 bytes or one 1024 bytes block.  The received data can also
+ * be an end of transmission, or a cancel.
+ *
+ * Returns :
+ *  >0           : size of the received block
+ *  0            : last block, ie. end of transmission, ie. EOT
+ * -EBADMSG      : malformed message (ie. sequence bi-bytes are not
+ *                 complementary), or CRC check error
+ * -EILSEQ       : block sequence number error wrt previously received block
+ * -ETIMEDOUT    : block not received before timeout passed
+ * -ECONNABORTED : transfer aborted by sender, ie. CAN
+ */
+static ssize_t xy_read_block(struct xyz_ctxt *proto, struct xy_block *blk,
+	uint64_t timeout)
+{
+	ssize_t rc, data_len = 0;
+	unsigned char hdr, seqs[2], crcs[2];
+	int crc = 0;
+	bool hdr_found = 0;
+	uint64_t start = get_time_ns();
+
+	while (!hdr_found) {
+		rc = xy_gets(proto->cdev, proto->fifo, &hdr, 1, timeout);
+		xy_dbg("read 0x%x(%c) -> %d\n", hdr, hdr, rc);
+		if (rc < 0)
+			goto out;
+		if (is_timeout(start, timeout))
+			goto timeout;
+		switch (hdr) {
+		case SOH:
+			data_len = 128;
+			hdr_found = 1;
+			proto->total_SOH++;
+			break;
+		case STX:
+			data_len = 1024;
+			hdr_found = 1;
+			proto->total_STX++;
+			break;
+		case CAN:
+			rc = -ECONNABORTED;
+			if (proto->total_CAN++ > MAX_CAN_BEFORE_ABORT)
+				goto out;
+			break;
+		case EOT:
+			rc = 0;
+			blk->len = 0;
+			goto out;
+		default:
+			break;
+		}
+	}
+
+	blk->seq = 0;
+	rc = xy_gets(proto->cdev, proto->fifo, seqs, 2, timeout);
+	if (rc < 0)
+		goto out;
+	blk->seq = seqs[0];
+	if (255 - seqs[0] != seqs[1])
+		return -EBADMSG;
+
+	rc = xy_gets(proto->cdev, proto->fifo, blk->buf, data_len, timeout);
+	if (rc < 0)
+		goto out;
+	blk->len = rc;
+
+	switch (proto->crc_mode) {
+	case CRC_ADD8:
+		rc = xy_gets(proto->cdev, proto->fifo, crcs, 1, timeout);
+		crc = crcs[0];
+		break;
+	case CRC_CRC16:
+		rc = xy_gets(proto->cdev, proto->fifo, crcs, 2, timeout);
+		crc = (crcs[0] << 8) + crcs[1];
+		break;
+	case CRC_NONE:
+		rc = 0;
+		break;
+	}
+	if (rc < 0)
+		goto out;
+
+	rc = check_crc(blk->buf, data_len, crc, proto->crc_mode);
+	if (rc < 0)
+		goto out;
+	return data_len;
+timeout:
+	return -ETIMEDOUT;
+out:
+	return rc;
+}
+
+static int check_blk_seq(struct xyz_ctxt *proto, struct xy_block *blk,
+	int read_rc)
+{
+	if (blk->seq == ((proto->next_blk - 1) % 256))
+		return -EALREADY;
+	if (blk->seq != proto->next_blk)
+		return -EILSEQ;
+	return read_rc;
+}
+
+static int parse_first_block(struct xyz_ctxt *proto, struct xy_block *blk)
+{
+	int filename_len;
+	char *str_num;
+
+	filename_len = strlen(blk->buf);
+	if (filename_len > blk->len)
+		return -EINVAL;
+	strlcpy(proto->filename, blk->buf, sizeof(proto->filename));
+	str_num = blk->buf + filename_len + 1;
+	strsep(&str_num, " ");
+	proto->file_len = simple_strtoul(blk->buf + filename_len + 1, NULL, 10);
+	return 1;
+}
+
+static int xy_get_file_header(struct xyz_ctxt *proto)
+{
+	struct xy_block blk;
+	int tries, rc = 0;
+
+	memset(&blk, 0, sizeof(blk));
+	proto->state = PROTO_STATE_GET_FILENAME;
+	proto->crc_mode = CRC_CRC16;
+	for (tries = 0; tries < MAX_RETRIES; tries++) {
+		xy_putc(proto->cdev,
+			   invite_filename_hdr[proto->mode][proto->crc_mode]);
+		rc = xy_read_block(proto, &blk, 3 * SECOND);
+		xy_dbg("read block returned %d\n", rc);
+		switch (rc) {
+		case -ECONNABORTED:
+			goto fail;
+		case -ETIMEDOUT:
+		case -EBADMSG:
+			if (proto->mode != PROTO_YMODEM_G)
+				xy_flush(proto->cdev, proto->fifo);
+			break;
+		case -EALREADY:
+		default:
+			proto->next_blk = 1;
+			xy_block_ack(proto);
+			proto->state = PROTO_STATE_NEGOCIATE_CRC;
+			rc = parse_first_block(proto, &blk);
+			return rc;
+		}
+
+		if (rc < 0 && tries++ >= MAX_RETRIES_WITH_CRC)
+			proto->crc_mode = CRC_ADD8;
+	}
+	rc = -ETIMEDOUT;
+fail:
+	proto->total_retries += tries;
+	return rc;
+}
+
+static int xy_await_header(struct xyz_ctxt *proto)
+{
+	int rc;
+
+	rc = xy_get_file_header(proto);
+	if (rc < 0)
+		return rc;
+	proto->state = PROTO_STATE_NEGOCIATE_CRC;
+	xy_dbg("header received, filename=%s, file length=%d\n",
+	       proto->filename, proto->file_len);
+	if (proto->filename[0])
+		proto->fd = open(proto->filename, O_WRONLY | O_CREAT);
+	else
+		proto->state = PROTO_STATE_FINISHED_XFER;
+	proto->nb_received = 0;
+	return rc;
+}
+
+static void xy_finish_file(struct xyz_ctxt *proto)
+{
+	close(proto->fd);
+	proto->fd = 0;
+	proto->state = PROTO_STATE_FINISHED_FILE;
+}
+
+static struct xyz_ctxt *xymodem_open(struct console_device *cdev,
+				     int proto_mode, int xmodem_fd)
+{
+	struct xyz_ctxt *proto;
+
+	proto = xzalloc(sizeof(struct xyz_ctxt));
+	proto->fifo = kfifo_alloc(INPUT_FIFO_SIZE);
+	proto->mode = proto_mode;
+	proto->cdev = cdev;
+	proto->crc_mode = CRC_CRC16;
+
+	if (is_xmodem(proto)) {
+		proto->fd = xmodem_fd;
+		proto->state = PROTO_STATE_NEGOCIATE_CRC;
+	} else {
+		proto->state = PROTO_STATE_GET_FILENAME;
+	}
+	xy_flush(proto->cdev, proto->fifo);
+	return proto;
+}
+
+static int xymodem_handle(struct xyz_ctxt *proto)
+{
+	int rc = 0, xfer_max, len = 0, again = 1, remain;
+	int crc_tries = 0, same_blk_retries = 0;
+	unsigned char invite;
+	struct xy_block blk;
+
+	while (again) {
+		switch (proto->state) {
+		case PROTO_STATE_GET_FILENAME:
+			crc_tries = 0;
+			rc = xy_await_header(proto);
+			if (rc < 0)
+				goto fail;
+			continue;
+		case PROTO_STATE_FINISHED_FILE:
+			if (is_xmodem(proto))
+				proto->state = PROTO_STATE_FINISHED_XFER;
+			else
+				proto->state = PROTO_STATE_GET_FILENAME;
+			xy_putc(proto->cdev, ACK);
+			continue;
+		case PROTO_STATE_FINISHED_XFER:
+			again = 0;
+			rc = 0;
+			goto out;
+		case PROTO_STATE_NEGOCIATE_CRC:
+			invite = invite_file_body[proto->mode][proto->crc_mode];
+			proto->next_blk = 1;
+			if (crc_tries++ > MAX_RETRIES_WITH_CRC)
+				proto->crc_mode = CRC_ADD8;
+			xy_putc(proto->cdev, invite);
+			/* Fall through */
+		case PROTO_STATE_RECEIVE_BODY:
+			rc = xy_read_block(proto, &blk, 3 * SECOND);
+			if (rc > 0) {
+				rc = check_blk_seq(proto, &blk, rc);
+				proto->state = PROTO_STATE_RECEIVE_BODY;
+			}
+			break;
+		}
+
+		if (proto->state != PROTO_STATE_RECEIVE_BODY)
+			continue;
+
+		switch (rc) {
+		case -ECONNABORTED:
+			goto fail;
+		case -ETIMEDOUT:
+			if (proto->mode == PROTO_YMODEM_G)
+				goto fail;
+			xy_flush(proto->cdev, proto->fifo);
+			xy_block_nack(proto);
+			break;
+		case -EBADMSG:
+		case -EILSEQ:
+			if (proto->mode == PROTO_YMODEM_G)
+				goto fail;
+			xy_flush(proto->cdev, proto->fifo);
+			xy_block_nack(proto);
+			break;
+		case -EALREADY:
+			xy_block_ack(proto);
+			break;
+		case 0:
+			xy_finish_file(proto);
+			break;
+		default:
+			remain = proto->file_len - proto->nb_received;
+			if (is_xmodem(proto))
+				xfer_max = blk.len;
+			else
+				xfer_max = min(blk.len, remain);
+			rc = write(proto->fd, blk.buf, xfer_max);
+			proto->next_blk = ((blk.seq + 1) % 256);
+			proto->nb_received += rc;
+			len += rc;
+			xy_block_ack(proto);
+			break;
+		}
+		if (rc < 0)
+			same_blk_retries++;
+		else
+			same_blk_retries = 0;
+		if (same_blk_retries > MAX_RETRIES)
+			goto fail;
+	}
+out:
+	return rc;
+fail:
+	if (proto->fd)
+		close(proto->fd);
+	return rc;
+}
+
+static void xymodem_close(struct xyz_ctxt *proto)
+{
+	xy_flush(proto->cdev, proto->fifo);
+	printf("\nxyModem - %d(SOH)/%d(STX)/%d(CAN) packets,"
+	       " %d retries\n",
+	       proto->total_SOH, proto->total_STX,
+	       proto->total_CAN, proto->total_retries);
+	kfifo_free(proto->fifo);
+}
+
+int do_load_serial_xmodem(struct console_device *cdev, int fd)
+{
+	struct xyz_ctxt *proto;
+	int rc;
+
+	proto = xymodem_open(cdev, PROTO_XMODEM, fd);
+	do {
+		rc = xymodem_handle(proto);
+	} while (rc > 0);
+	xymodem_close(proto);
+	return rc < 0 ? rc : 0;
+}
+EXPORT_SYMBOL(do_load_serial_xmodem);
+
+int do_load_serial_ymodem(struct console_device *cdev)
+{
+	struct xyz_ctxt *proto;
+	int rc;
+
+	proto = xymodem_open(cdev, PROTO_YMODEM, 0);
+	do {
+		rc = xymodem_handle(proto);
+	} while (rc > 0);
+	xymodem_close(proto);
+	return rc < 0 ? rc : 0;
+}
+EXPORT_SYMBOL(do_load_serial_ymodem);
+
+int do_load_serial_ymodemg(struct console_device *cdev)
+{
+	struct xyz_ctxt *proto;
+	int rc;
+
+	proto = xymodem_open(cdev, PROTO_YMODEM_G, 0);
+	do {
+		rc = xymodem_handle(proto);
+	} while (rc > 0);
+	xymodem_close(proto);
+	return rc < 0 ? rc : 0;
+}
+EXPORT_SYMBOL(do_load_serial_ymodemg);