Zabbix

/*

** Copyright (C) 2001-2025 Zabbix SIA

**

** This program is free software: you can redistribute it and/or modify it under the terms of

** the GNU Affero General Public License as published by the Free Software Foundation, version 3.

**

** 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 Affero General Public License for more details.

**

** You should have received a copy of the GNU Affero General Public License along with this program.

** If not, see <https://www.gnu.org/licenses/>.

**/

​

#include "zbxcomms.h"

#include "comms.h"

​

#include "zbxlog.h"

#include "zbxstr.h"

​

#define CMD_IAC     255

#define CMD_WILL    251

#define CMD_WONT    252

#define CMD_DO      253

#define CMD_DONT    254

#define OPT_SGA     3

​

static char prompt_char = '\0';

​

static int  telnet_waitsocket(ZBX_SOCKET socket_fd, short mode)

{

    int     rc;

    zbx_pollfd_t    pd;

​

    zabbix_log(LOG_LEVEL_DEBUG, "In %s()", __func__);

​

    pd.fd = socket_fd;

    pd.events = mode;

​

    if (0 > (rc = zbx_socket_poll(&pd, 1, 100)))

    {

        zabbix_log(LOG_LEVEL_DEBUG, "%s() poll() error rc:%d errno:%d error:[%s]", __func__, rc,

                zbx_socket_last_error(), zbx_strerror_from_system(zbx_socket_last_error()));

    }

    else if (0 < rc && POLLIN != (pd.revents & (POLLIN | POLLERR | POLLHUP | POLLNVAL)))

    {

        char    *errmsg;

​

        errmsg = socket_poll_error(pd.revents);

​

        zabbix_log(LOG_LEVEL_DEBUG, "%s() %s", __func__, errmsg);

        zbx_free(errmsg);

        rc = ZBX_PROTO_ERROR;

    }

​

    zabbix_log(LOG_LEVEL_DEBUG, "End of %s():%d", __func__, rc);

​

    return rc;

}

​

static ssize_t  telnet_socket_read(zbx_socket_t *s, void *buf, size_t count)

{

    ssize_t rc;