static int telnet_waitsocket(ZBX_SOCKET socket_fd, int mode)
{
const char *__function_name = "telnet_waitsocket";
struct timeval tv;
int rc;
fd_set fd, *readfd = NULL, *writefd = NULL;
zabbix_log(LOG_LEVEL_DEBUG, "In %s()", __function_name);
tv.tv_sec = 0;
tv.tv_usec = 100000; /* 1/10 sec */
FD_ZERO(&fd);
FD_SET(socket_fd, &fd);
if (WAIT_READ == mode)
readfd = &fd;
else
writefd = &fd;
rc = select((int)(socket_fd + 1), readfd, writefd, NULL, &tv);
if (ZBX_PROTO_ERROR == rc)
{
zabbix_log(LOG_LEVEL_DEBUG, "%s() rc:%d errno:%d error:[%s]", __function_name, rc,
zbx_socket_last_error(), strerror_from_system(zbx_socket_last_error()));
}
zabbix_log(LOG_LEVEL_DEBUG, "End of %s():%d", __function_name, rc);
return rc;
}
static ssize_t telnet_socket_write(ZBX_SOCKET socket_fd, const void *buf, size_t count)
{
const char *__function_name = "telnet_socket_write";
ssize_t rc;
int error;
zabbix_log(LOG_LEVEL_DEBUG, "In %s()", __function_name);
while (ZBX_PROTO_ERROR == (rc = ZBX_TCP_WRITE(socket_fd, buf, count)))
{
error = zbx_socket_last_error(); /* zabbix_log() resets the error code */
zabbix_log(LOG_LEVEL_DEBUG, "%s() rc:%d errno:%d error:[%s]",
__function_name, rc, error, strerror_from_system(error));
#ifdef _WINDOWS
if (WSAEWOULDBLOCK == error)
#else
if (EAGAIN == error)
#endif
{
telnet_waitsocket(socket_fd, WAIT_WRITE);
continue;
}
break;
}
zabbix_log(LOG_LEVEL_DEBUG, "End of %s():%d", __function_name, rc);
return rc;
}
ZBX_THREAD_ENTRY(trapper_thread, args)
{
double sec = 0.0;
zbx_socket_t s;
process_type = ((zbx_thread_args_t *)args)->process_type;
server_num = ((zbx_thread_args_t *)args)->server_num;
process_num = ((zbx_thread_args_t *)args)->process_num;
zabbix_log(LOG_LEVEL_INFORMATION, "%s #%d started [%s #%d]", get_program_type_string(program_type),
server_num, get_process_type_string(process_type), process_num);
memcpy(&s, (zbx_socket_t *)((zbx_thread_args_t *)args)->args, sizeof(zbx_socket_t));
#if defined(HAVE_POLARSSL) || defined(HAVE_GNUTLS) || defined(HAVE_OPENSSL)
zbx_tls_init_child();
find_psk_in_cache = DCget_psk_by_identity;
#endif
zbx_setproctitle("%s #%d [connecting to the database]", get_process_type_string(process_type), process_num);
DBconnect(ZBX_DB_CONNECT_NORMAL);
for (;;)
{
zbx_handle_log();
zbx_setproctitle("%s #%d [processed data in " ZBX_FS_DBL " sec, waiting for connection]",
get_process_type_string(process_type), process_num, sec);
update_selfmon_counter(ZBX_PROCESS_STATE_IDLE);
/* Trapper has to accept all types of connections it can accept with the specified configuration. */
/* Only after receiving data it is known who has sent them and one can decide to accept or discard */
/* the data. */
if (SUCCEED == zbx_tcp_accept(&s, ZBX_TCP_SEC_TLS_CERT | ZBX_TCP_SEC_TLS_PSK | ZBX_TCP_SEC_UNENCRYPTED))
{
zbx_timespec_t ts;
/* get connection timestamp */
zbx_timespec(&ts);
update_selfmon_counter(ZBX_PROCESS_STATE_BUSY);
zbx_setproctitle("%s #%d [processing data]", get_process_type_string(process_type),
process_num);
sec = zbx_time();
process_trapper_child(&s, &ts);
sec = zbx_time() - sec;
zbx_tcp_unaccept(&s);
}
else if (EINTR != zbx_socket_last_error())
{
zabbix_log(LOG_LEVEL_WARNING, "failed to accept an incoming connection: %s",
zbx_socket_strerror());
}
}
}
static ssize_t telnet_socket_read(ZBX_SOCKET socket_fd, void *buf, size_t count)
{
const char *__function_name = "telnet_socket_read";
ssize_t rc;
int error;
zabbix_log(LOG_LEVEL_DEBUG, "In %s()", __function_name);
while (ZBX_PROTO_ERROR == (rc = ZBX_TCP_READ(socket_fd, buf, count)))
{
error = zbx_socket_last_error(); /* zabbix_log() resets the error code */
zabbix_log(LOG_LEVEL_DEBUG, "%s() rc:%d errno:%d error:[%s]",
__function_name, rc, error, strerror_from_system(error));
#ifdef _WINDOWS
if (WSAEWOULDBLOCK == error)
#else
if (EAGAIN == error)
#endif
{
/* wait and if there is still an error or no input available */
/* we assume the other side has nothing more to say */
if (1 > (rc = telnet_waitsocket(socket_fd, WAIT_READ)))
goto ret;
continue;
}
break;
}
/* when ZBX_TCP_READ returns 0, it means EOF - let's consider it a permanent error */
/* note that if telnet_waitsocket() is zero, it is not a permanent condition */
if (0 == rc)
rc = ZBX_PROTO_ERROR;
ret:
zabbix_log(LOG_LEVEL_DEBUG, "End of %s():%d", __function_name, rc);
return rc;
}
ZBX_THREAD_ENTRY(listener_thread, args)
{
#if defined(HAVE_POLARSSL) || defined(HAVE_GNUTLS) || defined(HAVE_OPENSSL)
char *msg = NULL;
#endif
int ret;
zbx_socket_t s;
assert(args);
assert(((zbx_thread_args_t *)args)->args);
process_type = ((zbx_thread_args_t *)args)->process_type;
server_num = ((zbx_thread_args_t *)args)->server_num;
process_num = ((zbx_thread_args_t *)args)->process_num;
zabbix_log(LOG_LEVEL_INFORMATION, "%s #%d started [%s #%d]", get_program_type_string(program_type),
server_num, get_process_type_string(process_type), process_num);
memcpy(&s, (zbx_socket_t *)((zbx_thread_args_t *)args)->args, sizeof(zbx_socket_t));
zbx_free(args);
#if defined(HAVE_POLARSSL) || defined(HAVE_GNUTLS) || defined(HAVE_OPENSSL)
zbx_tls_init_child();
#endif
while (ZBX_IS_RUNNING())
{
zbx_setproctitle("listener #%d [waiting for connection]", process_num);
ret = zbx_tcp_accept(&s, configured_tls_accept_modes);
zbx_update_env(zbx_time());
if (SUCCEED == ret)
{
zbx_setproctitle("listener #%d [processing request]", process_num);
if ('\0' != *CONFIG_HOSTS_ALLOWED &&
SUCCEED == (ret = zbx_tcp_check_allowed_peers(&s, CONFIG_HOSTS_ALLOWED)))
{
#if defined(HAVE_POLARSSL) || defined(HAVE_GNUTLS) || defined(HAVE_OPENSSL)
if (ZBX_TCP_SEC_TLS_CERT != s.connection_type ||
SUCCEED == (ret = zbx_check_server_issuer_subject(&s, &msg)))
#endif
{
process_listener(&s);
}
}
zbx_tcp_unaccept(&s);
}
if (SUCCEED == ret || EINTR == zbx_socket_last_error())
continue;
#if defined(HAVE_POLARSSL) || defined(HAVE_GNUTLS) || defined(HAVE_OPENSSL)
if (NULL != msg)
{
zabbix_log(LOG_LEVEL_WARNING, "failed to accept an incoming connection: %s", msg);
zbx_free(msg);
}
else
#endif
{
zabbix_log(LOG_LEVEL_WARNING, "failed to accept an incoming connection: %s",
zbx_socket_strerror());
}
if (ZBX_IS_RUNNING())
zbx_sleep(1);
}
#ifdef _WINDOWS
ZBX_DO_EXIT();
zbx_thread_exit(EXIT_SUCCESS);
#endif
}
int telnet_execute(ZBX_SOCKET socket_fd, const char *command, AGENT_RESULT *result, const char *encoding)
{
const char *__function_name = "telnet_execute";
char buf[MAX_BUFFER_LEN];
size_t sz, offset;
int rc, ret = FAIL;
char *command_lf = NULL, *command_crlf = NULL;
size_t i, offset_lf, offset_crlf;
zabbix_log(LOG_LEVEL_DEBUG, "In %s()", __function_name);
/* `command' with multiple lines may contain CR+LF from the browser; */
/* it should be converted to plain LF to remove echo later on properly */
offset_lf = strlen(command);
command_lf = zbx_malloc(command_lf, offset_lf + 1);
zbx_strlcpy(command_lf, command, offset_lf + 1);
convert_telnet_to_unix_eol(command_lf, &offset_lf);
/* telnet protocol requires that end-of-line is transferred as CR+LF */
command_crlf = zbx_malloc(command_crlf, offset_lf * 2 + 1);
convert_unix_to_telnet_eol(command_lf, offset_lf, command_crlf, &offset_crlf);
telnet_socket_write(socket_fd, command_crlf, offset_crlf);
telnet_socket_write(socket_fd, "\r\n", 2);
sz = sizeof(buf);
offset = 0;
while (ZBX_PROTO_ERROR != (rc = telnet_read(socket_fd, buf, &sz, &offset)))
{
if (prompt_char == telnet_lastchar(buf, offset))
break;
}
convert_telnet_to_unix_eol(buf, &offset);
zabbix_log(LOG_LEVEL_DEBUG, "%s() command output:'%.*s'", __function_name, (int)offset, buf);
if (ZBX_PROTO_ERROR == rc)
{
SET_MSG_RESULT(result, zbx_dsprintf(NULL, "Cannot find prompt after command execution: %s",
strerror_from_system(zbx_socket_last_error())));
goto fail;
}
telnet_rm_echo(buf, &offset, command_lf, offset_lf);
/* multi-line commands may have returned additional prompts; */
/* this is not a perfect solution, because in case of multiple */
/* multi-line shell statements these prompts might appear in */
/* the middle of the output, but we still try to be helpful by */
/* removing additional prompts at least from the beginning */
for (i = 0; i < offset_lf; i++)
{
if ('\n' == command_lf[i])
{
if (SUCCEED != telnet_rm_echo(buf, &offset, "$ ", 2) &&
SUCCEED != telnet_rm_echo(buf, &offset, "# ", 2) &&
SUCCEED != telnet_rm_echo(buf, &offset, "> ", 2) &&
SUCCEED != telnet_rm_echo(buf, &offset, "% ", 2))
{
break;
}
}
}
telnet_rm_echo(buf, &offset, "\n", 1);
telnet_rm_prompt(buf, &offset);
zabbix_log(LOG_LEVEL_DEBUG, "%s() stripped command output:'%.*s'", __function_name, (int)offset, buf);
if (MAX_BUFFER_LEN == offset)
offset--;
buf[offset] = '\0';
SET_STR_RESULT(result, convert_to_utf8(buf, offset, encoding));
ret = SUCCEED;
fail:
zbx_free(command_lf);
zbx_free(command_crlf);
zabbix_log(LOG_LEVEL_DEBUG, "End of %s():%s", __function_name, zbx_result_string(ret));
return ret;
}