[RFC PATCH] commands: change Y-Modem implementation
Antony Pavlov
antonynpavlov at gmail.com
Sat Oct 27 01:49:00 EDT 2012
On 26 October 2012 23:00, Robert Jarzmik <robert.jarzmik at free.fr> wrote:
> The current Y-Modem implementation has some limitations:
> - Y-Modem/G protocol is not supported
> - Multiple files (aka. batch) transfers are not supported
> - Transfer speed over fast lines (USB console) is slow
> - Code is not trivial to maintain (personnal opinion)
>
> This implementation tries to address all these points by
> introducing loady2 command.
>
> The effects are :
> - transfer speed for Y-Modem over USB jumps from 2kBytes/s
> to 180kBytes/s
> - transfer speed for Y-Modem/G jumps to 200kBytes/s
> - multiple file transfers are possible
>
> This command was tested on a USB console. Before going any
> further, I'd like barebox communauty opinion about :
> - is this code more maintainable that xyzModem.c ?
> - is some xyzModem.c functionality missing ?
> - can anybody test it on a slow UART line (even better if
> it is noisy) to check protocol corner cases ?
I have just checked your Y-Modem implementation over 115200 bps UART.
Traditional 'loady' works fine, but neither 'loady2' nor 'loady2 -g'
does not work.
I use lrzsz-0.12.21-5 on my host.
> Signed-off-by: Robert Jarzmik <robert.jarzmik at free.fr>
> ---
> commands/Kconfig | 5 +
> commands/Makefile | 1 +
> commands/xymodem.c | 556 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 562 insertions(+)
> create mode 100644 commands/xymodem.c
>
> diff --git a/commands/Kconfig b/commands/Kconfig
> index 546e58e..adf7328 100644
> --- a/commands/Kconfig
> +++ b/commands/Kconfig
> @@ -264,6 +264,11 @@ config CMD_LOADY
> tristate
> prompt "loady"
>
> +config CMD_LOADY2
> + select CRC16
> + tristate
> + prompt "loady2"
> +
> config CMD_LOADS
> tristate
> prompt "loads"
> diff --git a/commands/Makefile b/commands/Makefile
> index ff98051..5576d8b 100644
> --- a/commands/Makefile
> +++ b/commands/Makefile
> @@ -4,6 +4,7 @@ obj-$(CONFIG_CMD_UIMAGE) += uimage.o
> obj-$(CONFIG_CMD_LINUX16) += linux16.o
> obj-$(CONFIG_CMD_LOADB) += loadb.o xyzModem.o
> obj-$(CONFIG_CMD_LOADY) += loadb.o xyzModem.o
> +obj-$(CONFIG_CMD_LOADY2) += xymodem.o
> obj-$(CONFIG_CMD_LOADS) += loads.o
> obj-$(CONFIG_CMD_ECHO) += echo.o
> obj-$(CONFIG_CMD_MEMORY) += mem.o
> diff --git a/commands/xymodem.c b/commands/xymodem.c
> new file mode 100644
> index 0000000..2e0822c
> --- /dev/null
> +++ b/commands/xymodem.c
> @@ -0,0 +1,556 @@
> +#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 <getopt.h>
> +#include <command.h>
> +#include <fs.h>
> +#include <poller.h>
> +#include <linux/byteorder/generic.h>
> +
> +#include <kfifo.h>
> +
> +#define proto_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 MAX_CAN_BEFORE_ABORT 5
> +
> +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
> + * @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;
> + 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 proto_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 proto_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 proto_gets(struct console_device *cdev, 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 (cdev->tstc(cdev))
> + buf[i++] = (unsigned char)(cdev->getc(cdev));
> + }
> +
> + return rc < 0 ? rc : i;
> +}
> +
> +static void proto_putc(struct console_device *cdev, unsigned char c)
> +{
> + cdev->putc(cdev, c);
> +}
> +
> +static void proto_flush(struct console_device *cdev)
> +{
> + while (cdev->tstc(cdev))
> + cdev->getc(cdev);
> +}
> +
> +static int is_xmodem(struct xyz_ctxt *proto)
> +{
> + return proto->mode == PROTO_XMODEM;
> +}
> +
> +static void proto_block_ack(struct xyz_ctxt *proto)
> +{
> + unsigned char c = block_ack[proto->mode][proto->crc_mode];
> +
> + if (c)
> + proto_putc(proto->cdev, c);
> +}
> +
> +static void proto_block_nack(struct xyz_ctxt *proto)
> +{
> + unsigned char c = block_nack[proto->mode][proto->crc_mode];
> +
> + if (c)
> + proto_putc(proto->cdev, c);
> +}
> +
> +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);
> + proto_dbg("crc16: received = %x, calculated=%x\n", crc, crc16);
> + return crc16 == crc ? 0 : -EBADMSG;
> + case CRC_NONE:
> + return 0;
> + default:
> + return -EBADMSG;
> + }
> +}
> +
> +static ssize_t proto_read_block(struct xyz_ctxt *proto, struct proto_block *blk,
> + uint64_t timeout)
> +{
> + ssize_t rc, data_len = 0;
> + unsigned char hdr, seqs[2];
> + int crc = 0, hdr_found = 0;
> + uint64_t start = get_time_ns();
> +
> + while (!hdr_found) {
> + rc = proto_gets(proto->cdev, &hdr, 1, timeout);
> + proto_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 = proto_gets(proto->cdev, seqs, 2, timeout);
> + if (rc < 0)
> + goto out;
> + blk->seq = seqs[0];
> + if (255 - seqs[0] != seqs[1])
> + return -EBADMSG;
> +
> + rc = proto_gets(proto->cdev, blk->buf, data_len, timeout);
> + if (rc < 0)
> + goto out;
> + blk->len = rc;
> +
> + switch (proto->crc_mode) {
> + case CRC_ADD8:
> + rc = proto_gets(proto->cdev,
> + (unsigned char *)&crc, 1, timeout);
> + break;
> + case CRC_CRC16:
> + rc = proto_gets(proto->cdev,
> + (unsigned char *)&crc, 2, timeout);
> + crc = be16_to_cpu(crc);
> + 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 proto_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 proto_block *blk)
> +{
> + int filename_len;
> + char *str_num;
> +
> + filename_len = strlen(blk->buf);
> + if (filename_len > blk->len)
> + return -EINVAL;
> + memset(proto->filename, 0, sizeof(proto->filename));
> + strncpy(proto->filename, blk->buf, filename_len);
> + 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 proto_get_file_header(struct xyz_ctxt *proto)
> +{
> + struct proto_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++) {
> + proto_putc(proto->cdev,
> + invite_filename_hdr[proto->mode][proto->crc_mode]);
> + rc = proto_read_block(proto, &blk, 3 * SECOND);
> + proto_dbg("read block returned %d\n", rc);
> + switch (rc) {
> + case -ECONNABORTED:
> + goto fail;
> + case -ETIMEDOUT:
> + if (proto->mode != PROTO_YMODEM_G)
> + mdelay(1000);
> + break;
> + case -EBADMSG:
> + /* The NACK/C/G char will be sent by invite_file_body */
> + break;
> + case -EALREADY:
> + default:
> + proto->next_blk = 1;
> + proto_block_ack(proto);
> + proto->crc_mode = CRC_CRC16;
> + 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:
> + return rc;
> +}
> +
> +static int proto_await_header(struct xyz_ctxt *proto)
> +{
> + int rc;
> +
> + rc = proto_get_file_header(proto);
> + if (rc < 0)
> + return rc;
> + if (is_xmodem(proto))
> + proto->state = PROTO_STATE_RECEIVE_BODY;
> + else
> + proto->state = PROTO_STATE_NEGOCIATE_CRC;
> + proto_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;
> +
> + return rc;
> +}
> +
> +static void proto_finish_file(struct xyz_ctxt *proto)
> +{
> + close(proto->fd);
> + proto->fd = 0;
> + proto->state = PROTO_STATE_FINISHED_FILE;
> +}
> +
> +static struct xyz_ctxt *proto_open(struct console_device *cdev,
> + int proto_mode, char *xmodem_filename)
> +{
> + struct xyz_ctxt *proto;
> +
> + proto = xzalloc(sizeof(struct xyz_ctxt));
> + proto->mode = proto_mode;
> + proto->cdev = cdev;
> +
> + if (is_xmodem(proto)) {
> + proto->fd = open(xmodem_filename, O_WRONLY | O_CREAT);
> + proto->state = PROTO_STATE_RECEIVE_BODY;
> + } else {
> + proto->state = PROTO_STATE_GET_FILENAME;
> + }
> + proto_flush(proto->cdev);
> + return proto;
> +}
> +
> +static int proto_handle(struct xyz_ctxt *proto)
> +{
> + int rc = 0, xfer_max, len = 0, again = 1;
> + struct proto_block blk;
> +
> + while (again) {
> + switch (proto->state) {
> + case PROTO_STATE_GET_FILENAME:
> + rc = proto_await_header(proto);
> + if (rc < 0)
> + goto fail;
> + continue;
> + case PROTO_STATE_FINISHED_FILE:
> + rc = proto_read_block(proto, &blk, 3 * SECOND);
> + if (rc < 0)
> + goto fail;
> + if (rc > 0)
> + continue;
> + if (is_xmodem(proto))
> + proto->state = PROTO_STATE_FINISHED_XFER;
> + else
> + proto->state = PROTO_STATE_GET_FILENAME;
> + proto_putc(proto->cdev, ACK);
> + continue;
> + case PROTO_STATE_FINISHED_XFER:
> + again = 0;
> + rc = 0;
> + goto out;
> + case PROTO_STATE_NEGOCIATE_CRC:
> + proto_putc(proto->cdev,
> + invite_file_body[proto->mode][proto->crc_mode]);
> + /* Fall through */
> + case PROTO_STATE_RECEIVE_BODY:
> + rc = proto_read_block(proto, &blk, 3 * SECOND);
> + if (rc > 0) {
> + rc = check_blk_seq(proto, &blk, rc);
> + proto->state = PROTO_STATE_RECEIVE_BODY;
> + }
> + break;
> + }
> +
> + switch (rc) {
> + case -ECONNABORTED:
> + goto fail;
> + case -ETIMEDOUT:
> + if (proto->mode == PROTO_YMODEM_G)
> + goto fail;
> + continue;
> + case -EBADMSG:
> + case -EILSEQ:
> + if (proto->mode == PROTO_YMODEM_G)
> + goto fail;
> + proto->total_retries++;
> + proto_block_nack(proto);
> + break;
> + case -EALREADY:
> + proto_block_ack(proto);
> + break;
> + case 0:
> + proto_finish_file(proto);
> + break;
> + default:
> + if (is_xmodem(proto))
> + xfer_max = blk.len;
> + else
> + xfer_max = min(blk.len,
> + proto->file_len - proto->nb_received);
> + rc = write(proto->fd, blk.buf, xfer_max);
> + proto->next_blk = ((blk.seq + 1) % 256);
> + proto->nb_received += rc;
> + len += rc;
> + proto_block_ack(proto);
> + if (xfer_max < blk.len || blk.len == 0)
> + proto_finish_file(proto);
> + continue;
> + }
> + }
> +out:
> + return rc;
> +fail:
> + if (proto->fd)
> + close(proto->fd);
> + return rc;
> +}
> +
> +/**
> + * @brief returns current used console device
> + *
> + * @return console device which is registered with CONSOLE_STDIN and
> + * CONSOLE_STDOUT
> + */
> +static struct console_device *get_current_console(void)
> +{
> + struct console_device *cdev;
> + /*
> + * Assumption to have BOTH CONSOLE_STDIN AND STDOUT in the
> + * same output console
> + */
> + for_each_console(cdev) {
> + if ((cdev->f_active & (CONSOLE_STDIN | CONSOLE_STDOUT)))
> + return cdev;
> + }
> + return NULL;
> +}
> +
> +static void proto_close(struct xyz_ctxt *proto)
> +{
> + printf("xyModem - %d(SOH)/%d(STX)/%d(CAN) packets,"
> + " %d retries\n",
> + proto->total_SOH, proto->total_STX,
> + proto->total_CAN, proto->total_retries);
> +}
> +
> +/**
> + * @brief provide the loady2(ymodem)
> + *
> + * @param cmdtp
> + * @param argc
> + * @param argv
> + *
> + * @return success or failure
> + */
> +static int do_load_serial_bin(int argc, char *argv[])
> +{
> + int use_ymodem_g = 0, load_baudrate = -1, rc, opt;
> + struct console_device *cdev;
> + struct xyz_ctxt *proto;
> + ssize_t size = 0;
> +
> + while ((opt = getopt(argc, argv, "b:g")) > 0) {
> + switch (opt) {
> + case 'b':
> + load_baudrate = (int)simple_strtoul(optarg, NULL, 10);
> + break;
> + case 'g':
> + use_ymodem_g = 1;
> + break;
> + default:
> + perror(argv[0]);
> + return 1;
> + }
> + }
> +
> + cdev = get_current_console();
> + proto_flush(cdev);
> + proto = proto_open(cdev, use_ymodem_g ? PROTO_YMODEM_G : PROTO_YMODEM,
> + "");
> + while ((rc = proto_handle(proto)) > 0)
> + size += rc;
> + proto_close(proto);
> + proto_flush(cdev);
> + return rc < 0 ? rc : COMMAND_SUCCESS;
> +}
> +
> +#ifdef CONFIG_CMD_LOADY2
> +static const __maybe_unused char cmd_loady2_help[] =
> + "[OPTIONS]\n"
> + " -b baud - baudrate at which to download - defaults to "
> + "console baudrate\n"
> + " -g - use ymodem-g instead of ymodem";
> +
> +BAREBOX_CMD_START(loady2)
> + .cmd = do_load_serial_bin,
> + .usage = "Load binary file over serial line (ymodem mode)",
> + BAREBOX_CMD_HELP(cmd_loady2_help)
> +BAREBOX_CMD_END
> +#endif
> --
> 1.7.10
>
>
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--
Best regards,
Antony Pavlov
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