jsp_server.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2014 by Franck Jullien                                  *
 *   franck.jullien@gmail.com                                              *
 *                                                                         *
 *   Based on ./src/server/telnet_server.c                                 *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include <server/telnet_server.h>
 
#include "or1k_tap.h"
#include "or1k_du.h"
#include "jsp_server.h"
 
static char *jsp_port;
 
static const char * const negotiate =
    "\xFF\xFB\x03"          /* IAC WILL Suppress Go Ahead */
    "\xFF\xFB\x01"          /* IAC WILL Echo */
    "\xFF\xFD\x03"          /* IAC DO Suppress Go Ahead */
    "\xFF\xFE\x01";         /* IAC DON'T Echo */
 
/* The only way we can detect that the socket is closed is the first time
 * we write to it, we will fail. Subsequent write operations will
 * succeed. Shudder!
 */
static int telnet_write(struct connection *connection, const void *data, int len)
{
    struct telnet_connection *t_con = connection->priv;
    if (t_con->closed)
        return ERROR_SERVER_REMOTE_CLOSED;
 
    if (connection_write(connection, data, len) == len)
        return ERROR_OK;
    t_con->closed = 1;
    return ERROR_SERVER_REMOTE_CLOSED;
}
 
static int jsp_poll_read(void *priv)
{
    struct jsp_service *jsp_service = (struct jsp_service *)priv;
    unsigned char out_buffer[10];
    unsigned char in_buffer[10];
    int out_len = 0;
    int in_len;
 
    if (!jsp_service->connection)
        return ERROR_FAIL;
 
    memset(out_buffer, 0, 10);
 
    or1k_adv_jtag_jsp_xfer(jsp_service->jtag_info, &out_len, out_buffer, &in_len, in_buffer);
    if (in_len)
        telnet_write(jsp_service->connection, in_buffer, in_len);
 
    return ERROR_OK;
}
 
static int jsp_new_connection(struct connection *connection)
{
    struct telnet_connection *telnet_connection = malloc(sizeof(struct telnet_connection));
    struct jsp_service *jsp_service = connection->service->priv;
 
    connection->priv = telnet_connection;
 
    /* initialize telnet connection information */
    telnet_connection->closed = 0;
    telnet_connection->line_size = 0;
    telnet_connection->line_cursor = 0;
    telnet_connection->state = TELNET_STATE_DATA;
 
    /* negotiate telnet options */
    telnet_write(connection, negotiate, strlen(negotiate));
 
    /* print connection banner */
    if (jsp_service->banner) {
        telnet_write(connection, jsp_service->banner, strlen(jsp_service->banner));
        telnet_write(connection, "\r\n", 2);
    }
 
    jsp_service->connection = connection;
 
    int retval = target_register_timer_callback(&jsp_poll_read, 1,
        TARGET_TIMER_TYPE_PERIODIC, jsp_service);
    if (retval != ERROR_OK)
        return retval;
 
    return ERROR_OK;
}
 
static int jsp_input(struct connection *connection)
{
    int bytes_read;
    unsigned char buffer[TELNET_BUFFER_SIZE];
    unsigned char *buf_p;
    struct telnet_connection *t_con = connection->priv;
    struct jsp_service *jsp_service = connection->service->priv;
 
    bytes_read = connection_read(connection, buffer, TELNET_BUFFER_SIZE);
 
    if (bytes_read == 0)
        return ERROR_SERVER_REMOTE_CLOSED;
    else if (bytes_read == -1) {
        LOG_ERROR("error during read: %s", strerror(errno));
        return ERROR_SERVER_REMOTE_CLOSED;
    }
 
    buf_p = buffer;
    while (bytes_read) {
        switch (t_con->state) {
            case TELNET_STATE_DATA:
                if (*buf_p == 0xff)
                    t_con->state = TELNET_STATE_IAC;
                else {
                    int out_len = 1;
                    int in_len;
                    unsigned char in_buffer[10];
                    or1k_adv_jtag_jsp_xfer(jsp_service->jtag_info,
                                   &out_len, buf_p, &in_len,
                                   in_buffer);
                    if (in_len)
                        telnet_write(connection,
                                 in_buffer, in_len);
                }
                break;
            case TELNET_STATE_IAC:
                switch (*buf_p) {
                case 0xfe:
                    t_con->state = TELNET_STATE_DONT;
                    break;
                case 0xfd:
                    t_con->state = TELNET_STATE_DO;
                    break;
                case 0xfc:
                    t_con->state = TELNET_STATE_WONT;
                    break;
                case 0xfb:
                    t_con->state = TELNET_STATE_WILL;
                    break;
                }
                break;
            case TELNET_STATE_SB:
                break;
            case TELNET_STATE_SE:
                break;
            case TELNET_STATE_WILL:
            case TELNET_STATE_WONT:
            case TELNET_STATE_DO:
            case TELNET_STATE_DONT:
                t_con->state = TELNET_STATE_DATA;
                break;
            default:
                LOG_ERROR("unknown telnet state");
                exit(-1);
        }
 
        bytes_read--;
        buf_p++;
    }
 
    return ERROR_OK;
}
 
static int jsp_connection_closed(struct connection *connection)
{
    struct jsp_service *jsp_service = connection->service->priv;
 
    int retval = target_unregister_timer_callback(&jsp_poll_read, jsp_service);
    if (retval != ERROR_OK)
        return retval;
 
    free(connection->priv);
    connection->priv = NULL;
    return ERROR_OK;
}
 
static const struct service_driver jsp_service_driver = {
    .name = "jsp",
    .new_connection_during_keep_alive_handler = NULL,
    .new_connection_handler = jsp_new_connection,
    .input_handler = jsp_input,
    .connection_closed_handler = jsp_connection_closed,
    .keep_client_alive_handler = NULL,
};
 
int jsp_init(struct or1k_jtag *jtag_info, char *banner)
{
    struct jsp_service *jsp_service = malloc(sizeof(struct jsp_service));
    jsp_service->banner = banner;
    jsp_service->jtag_info = jtag_info;
 
    return add_service(&jsp_service_driver, jsp_port, 1, jsp_service);
}
 
COMMAND_HANDLER(handle_jsp_port_command)
{
    return CALL_COMMAND_HANDLER(server_pipe_command, &jsp_port);
}
 
static const struct command_registration jsp_command_handlers[] = {
    {
        .name = "jsp_port",
        .handler = handle_jsp_port_command,
        .mode = COMMAND_ANY,
        .help = "Specify port on which to listen "
            "for incoming JSP telnet connections.",
        .usage = "[port_num]",
    },
    COMMAND_REGISTRATION_DONE
};
 
int jsp_register_commands(struct command_context *cmd_ctx)
{
    jsp_port = strdup("7777");
    return register_commands(cmd_ctx, NULL, jsp_command_handlers);
}
 
void jsp_service_free(void)
{
    free(jsp_port);
}