circuitpython/cc3200/telnet/telnet.c

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/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2015 Daniel Campora
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdint.h>
#include "py/mpconfig.h"
#include MICROPY_HAL_H
#include "py/obj.h"
#include "telnet.h"
#include "simplelink.h"
#include "modwlan.h"
#include "modusocket.h"
#include "debug.h"
#include "mpexception.h"
#include "serverstask.h"
#include "genhdr/mpversion.h"
/******************************************************************************
DEFINE PRIVATE CONSTANTS
******************************************************************************/
#define TELNET_PORT 23
// rxRindex and rxWindex must be uint8_t and TELNET_RX_BUFFER_SIZE == 256
#define TELNET_RX_BUFFER_SIZE 256
#define TELNET_MAX_CLIENTS 1
#define TELNET_TX_RETRIES_MAX 25
#define TELNET_WAIT_TIME_MS 5
#define TELNET_LOGIN_RETRIES_MAX 3
#define TELNET_TIMEOUT_MS 300000 // 5 minutes
#define TELNET_CYCLE_TIME_MS (SERVERS_CYCLE_TIME_MS * 2)
/******************************************************************************
DEFINE PRIVATE TYPES
******************************************************************************/
typedef enum {
E_TELNET_RESULT_OK = 0,
E_TELNET_RESULT_AGAIN,
E_TELNET_RESULT_FAILED
} telnet_result_t;
typedef enum {
E_TELNET_STE_DISABLED = 0,
E_TELNET_STE_START,
E_TELNET_STE_LISTEN,
E_TELNET_STE_CONNECTED,
E_TELNET_STE_LOGGED_IN
} telnet_state_t;
typedef enum {
E_TELNET_STE_SUB_WELCOME,
E_TELNET_STE_SUB_SND_USER_OPTIONS,
E_TELNET_STE_SUB_REQ_USER,
E_TELNET_STE_SUB_GET_USER,
E_TELNET_STE_SUB_REQ_PASSWORD,
E_TELNET_STE_SUB_SND_PASSWORD_OPTIONS,
E_TELNET_STE_SUB_GET_PASSWORD,
E_TELNET_STE_SUB_INVALID_LOGGIN,
E_TELNET_STE_SUB_SND_REPL_OPTIONS,
E_TELNET_STE_SUB_LOGGIN_SUCCESS
} telnet_connected_substate_t;
typedef union {
telnet_connected_substate_t connected;
} telnet_substate_t;
typedef struct {
uint8_t *rxBuffer;
uint32_t timeout;
telnet_state_t state;
telnet_substate_t substate;
int16_t sd;
int16_t n_sd;
// rxRindex and rxWindex must be uint8_t and TELNET_RX_BUFFER_SIZE == 256
uint8_t rxWindex;
uint8_t rxRindex;
uint8_t txRetries;
uint8_t logginRetries;
bool enabled;
bool credentialsValid;
} telnet_data_t;
/******************************************************************************
DECLARE PRIVATE DATA
******************************************************************************/
static telnet_data_t telnet_data;
static const char* telnet_welcome_msg = "Micro Python " MICROPY_GIT_TAG " on " MICROPY_BUILD_DATE "; " MICROPY_HW_BOARD_NAME " with " MICROPY_HW_MCU_NAME "\r\n";
static const char* telnet_request_user = "Login as:";
static const char* telnet_request_password = "Password:";
static const char* telnet_invalid_loggin = "\r\nInvalid credentials, try again.\r\n";
static const char* telnet_loggin_success = "\r\nLogin succeeded!\r\nType \"help()\" for more information.\r\n";
static const uint8_t telnet_options_user[] = // IAC WONT ECHO IAC WONT SUPPRESS_GO_AHEAD IAC WILL LINEMODE
{ 255, 252, 1, 255, 252, 3, 255, 251, 34 };
static const uint8_t telnet_options_pass[] = // IAC WILL ECHO IAC WONT SUPPRESS_GO_AHEAD IAC WILL LINEMODE
{ 255, 251, 1, 255, 252, 3, 255, 251, 34 };
static const uint8_t telnet_options_repl[] = // IAC WILL ECHO IAC WILL SUPPRESS_GO_AHEAD IAC WONT LINEMODE
{ 255, 251, 1, 255, 251, 3, 255, 252, 34 };
/******************************************************************************
DECLARE PRIVATE FUNCTIONS
******************************************************************************/
static void telnet_wait_for_enabled (void);
static bool telnet_create_socket (void);
static void telnet_wait_for_connection (void);
static void telnet_send_and_proceed (void *data, _i16 Len, telnet_connected_substate_t next_state);
static telnet_result_t telnet_send_non_blocking (void *data, _i16 Len);
static telnet_result_t telnet_recv_text_non_blocking (void *buff, _i16 Maxlen, _i16 *rxLen);
static void telnet_process (void);
static int telnet_process_credential (char *credential, _i16 rxLen);
static void telnet_parse_input (uint8_t *str, int16_t *len);
static bool telnet_send_with_retries (int16_t sd, const void *pBuf, int16_t len);
static void telnet_reset_buffer (void);
/******************************************************************************
DEFINE PUBLIC FUNCTIONS
******************************************************************************/
void telnet_init (void) {
// Allocate memory for the receive buffer (from the RTOS heap)
ASSERT ((telnet_data.rxBuffer = mem_Malloc(TELNET_RX_BUFFER_SIZE)) != NULL);
telnet_data.state = E_TELNET_STE_DISABLED;
}
void telnet_run (void) {
_i16 rxLen;
switch (telnet_data.state) {
case E_TELNET_STE_DISABLED:
telnet_wait_for_enabled();
break;
case E_TELNET_STE_START:
if (telnet_create_socket()) {
telnet_data.state = E_TELNET_STE_LISTEN;
}
break;
case E_TELNET_STE_LISTEN:
telnet_wait_for_connection();
break;
case E_TELNET_STE_CONNECTED:
switch (telnet_data.substate.connected) {
case E_TELNET_STE_SUB_WELCOME:
telnet_send_and_proceed((void *)telnet_welcome_msg, strlen(telnet_welcome_msg), E_TELNET_STE_SUB_SND_USER_OPTIONS);
break;
case E_TELNET_STE_SUB_SND_USER_OPTIONS:
telnet_send_and_proceed((void *)telnet_options_user, sizeof(telnet_options_user), E_TELNET_STE_SUB_REQ_USER);
break;
case E_TELNET_STE_SUB_REQ_USER:
// to catch any left over characters from the previous actions
telnet_recv_text_non_blocking(telnet_data.rxBuffer, TELNET_RX_BUFFER_SIZE, &rxLen);
telnet_send_and_proceed((void *)telnet_request_user, strlen(telnet_request_user), E_TELNET_STE_SUB_GET_USER);
break;
case E_TELNET_STE_SUB_GET_USER:
if (E_TELNET_RESULT_OK == telnet_recv_text_non_blocking(telnet_data.rxBuffer + telnet_data.rxWindex,
TELNET_RX_BUFFER_SIZE - telnet_data.rxWindex,
&rxLen)) {
int result;
if ((result = telnet_process_credential (servers_user, rxLen))) {
telnet_data.credentialsValid = result > 0 ? true : false;
telnet_data.substate.connected = E_TELNET_STE_SUB_REQ_PASSWORD;
}
}
break;
case E_TELNET_STE_SUB_REQ_PASSWORD:
telnet_send_and_proceed((void *)telnet_request_password, strlen(telnet_request_password), E_TELNET_STE_SUB_SND_PASSWORD_OPTIONS);
break;
case E_TELNET_STE_SUB_SND_PASSWORD_OPTIONS:
// to catch any left over characters from the previous actions
telnet_recv_text_non_blocking(telnet_data.rxBuffer, TELNET_RX_BUFFER_SIZE, &rxLen);
telnet_send_and_proceed((void *)telnet_options_pass, sizeof(telnet_options_pass), E_TELNET_STE_SUB_GET_PASSWORD);
break;
case E_TELNET_STE_SUB_GET_PASSWORD:
if (E_TELNET_RESULT_OK == telnet_recv_text_non_blocking(telnet_data.rxBuffer + telnet_data.rxWindex,
TELNET_RX_BUFFER_SIZE - telnet_data.rxWindex,
&rxLen)) {
int result;
if ((result = telnet_process_credential (servers_pass, rxLen))) {
if ((telnet_data.credentialsValid = telnet_data.credentialsValid && (result > 0 ? true : false))) {
telnet_data.substate.connected = E_TELNET_STE_SUB_SND_REPL_OPTIONS;
}
else {
telnet_data.substate.connected = E_TELNET_STE_SUB_INVALID_LOGGIN;
}
}
}
break;
case E_TELNET_STE_SUB_INVALID_LOGGIN:
if (E_TELNET_RESULT_OK == telnet_send_non_blocking((void *)telnet_invalid_loggin, strlen(telnet_invalid_loggin))) {
telnet_data.credentialsValid = true;
if (++telnet_data.logginRetries >= TELNET_LOGIN_RETRIES_MAX) {
telnet_reset();
}
else {
telnet_data.substate.connected = E_TELNET_STE_SUB_SND_USER_OPTIONS;
}
}
break;
case E_TELNET_STE_SUB_SND_REPL_OPTIONS:
telnet_send_and_proceed((void *)telnet_options_repl, sizeof(telnet_options_repl), E_TELNET_STE_SUB_LOGGIN_SUCCESS);
break;
case E_TELNET_STE_SUB_LOGGIN_SUCCESS:
if (E_TELNET_RESULT_OK == telnet_send_non_blocking((void *)telnet_loggin_success, strlen(telnet_loggin_success))) {
// clear the current line and force the prompt
telnet_reset_buffer();
telnet_data.state= E_TELNET_STE_LOGGED_IN;
}
default:
break;
}
break;
case E_TELNET_STE_LOGGED_IN:
telnet_process();
break;
default:
break;
}
if (telnet_data.state >= E_TELNET_STE_CONNECTED) {
if (telnet_data.timeout++ > (TELNET_TIMEOUT_MS / TELNET_CYCLE_TIME_MS)) {
telnet_reset();
}
}
}
void telnet_tx_strn (const char *str, int len) {
if (len > 0 && telnet_data.n_sd > 0) {
telnet_send_with_retries(telnet_data.n_sd, str, len);
}
}
void telnet_tx_strn_cooked (const char *str, uint len) {
int32_t nslen = 0;
const char *_str = str;
for (int i = 0; i < len; i++) {
if (str[i] == '\n') {
telnet_send_with_retries(telnet_data.n_sd, _str, nslen);
telnet_send_with_retries(telnet_data.n_sd, "\r\n", 2);
_str += nslen + 1;
nslen = 0;
}
else {
nslen++;
}
}
if (_str < str + len) {
telnet_send_with_retries(telnet_data.n_sd, _str, nslen);
}
}
bool telnet_rx_any (void) {
return (telnet_data.n_sd > 0) ? ((telnet_data.rxRindex != telnet_data.rxWindex) &&
(telnet_data.state == E_TELNET_STE_LOGGED_IN)) : false;
}
int telnet_rx_char (void) {
int rx_char = -1;
if (telnet_data.rxRindex != telnet_data.rxWindex) {
// rxRindex must be uint8_t and TELNET_RX_BUFFER_SIZE == 256 so that it wraps around automatically
rx_char = (int)telnet_data.rxBuffer[telnet_data.rxRindex++];
}
return rx_char;
}
void telnet_enable (void) {
telnet_data.enabled = true;
}
void telnet_disable (void) {
telnet_reset();
telnet_data.enabled = false;
telnet_data.state = E_TELNET_STE_DISABLED;
}
void telnet_reset (void) {
// close the connection and start all over again
servers_close_socket(&telnet_data.n_sd);
servers_close_socket(&telnet_data.sd);
telnet_data.state = E_TELNET_STE_START;
}
bool telnet_is_enabled (void) {
return telnet_data.enabled;
}
bool telnet_is_active (void) {
return (telnet_data.state == E_TELNET_STE_LOGGED_IN);
}
/******************************************************************************
DEFINE PRIVATE FUNCTIONS
******************************************************************************/
static void telnet_wait_for_enabled (void) {
// Init telnet's data
telnet_data.n_sd = -1;
telnet_data.sd = -1;
// Check if the telnet service has been enabled
if (telnet_data.enabled) {
telnet_data.state = E_TELNET_STE_START;
}
}
static bool telnet_create_socket (void) {
SlSockNonblocking_t nonBlockingOption;
sockaddr_in sServerAddress;
_i16 result;
// Open a socket for telnet
ASSERT ((telnet_data.sd = sl_Socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) > 0);
if (telnet_data.sd > 0) {
// add the socket to the network administration
modusocket_socket_add(telnet_data.sd, false);
// Enable non-blocking mode
nonBlockingOption.NonblockingEnabled = 1;
ASSERT (sl_SetSockOpt(telnet_data.sd, SOL_SOCKET, SL_SO_NONBLOCKING, &nonBlockingOption, sizeof(nonBlockingOption)) == SL_SOC_OK);
// Bind the socket to a port number
sServerAddress.sin_family = AF_INET;
sServerAddress.sin_addr.s_addr = INADDR_ANY;
sServerAddress.sin_port = htons(TELNET_PORT);
ASSERT (sl_Bind(telnet_data.sd, (const SlSockAddr_t *)&sServerAddress, sizeof(sServerAddress)) == SL_SOC_OK);
// Start listening
ASSERT ((result = sl_Listen (telnet_data.sd, TELNET_MAX_CLIENTS)) == SL_SOC_OK);
return (result == SL_SOC_OK) ? true : false;
}
return false;
}
static void telnet_wait_for_connection (void) {
SlSocklen_t in_addrSize;
sockaddr_in sClientAddress;
// accepts a connection from a TCP client, if there is any, otherwise returns SL_EAGAIN
telnet_data.n_sd = sl_Accept(telnet_data.sd, (SlSockAddr_t *)&sClientAddress, (SlSocklen_t *)&in_addrSize);
if (telnet_data.n_sd == SL_EAGAIN) {
return;
}
else {
if (telnet_data.n_sd <= 0) {
// error
telnet_reset();
return;
}
// close the listening socket, we don't need it anymore
servers_close_socket(&telnet_data.sd);
// add the new socket to the network administration
modusocket_socket_add(telnet_data.n_sd, false);
// client connected, so go on
telnet_data.rxWindex = 0;
telnet_data.rxRindex = 0;
telnet_data.txRetries = 0;
telnet_data.state = E_TELNET_STE_CONNECTED;
telnet_data.substate.connected = E_TELNET_STE_SUB_WELCOME;
telnet_data.credentialsValid = true;
telnet_data.logginRetries = 0;
telnet_data.timeout = 0;
}
}
static void telnet_send_and_proceed (void *data, _i16 Len, telnet_connected_substate_t next_state) {
if (E_TELNET_RESULT_OK == telnet_send_non_blocking(data, Len)) {
telnet_data.substate.connected = next_state;
}
}
static telnet_result_t telnet_send_non_blocking (void *data, _i16 Len) {
int16_t result = sl_Send(telnet_data.n_sd, data, Len, 0);
if (result > 0) {
telnet_data.txRetries = 0;
return E_TELNET_RESULT_OK;
}
else if ((TELNET_TX_RETRIES_MAX >= ++telnet_data.txRetries) && (result == SL_EAGAIN)) {
return E_TELNET_RESULT_AGAIN;
}
else {
// error
telnet_reset();
return E_TELNET_RESULT_FAILED;
}
}
static telnet_result_t telnet_recv_text_non_blocking (void *buff, _i16 Maxlen, _i16 *rxLen) {
*rxLen = sl_Recv(telnet_data.n_sd, buff, Maxlen, 0);
// if there's data received, parse it
if (*rxLen > 0) {
telnet_data.timeout = 0;
telnet_parse_input (buff, rxLen);
if (*rxLen > 0) {
return E_TELNET_RESULT_OK;
}
}
else if (*rxLen != SL_EAGAIN) {
// error
telnet_reset();
return E_TELNET_RESULT_FAILED;
}
return E_TELNET_RESULT_AGAIN;
}
static void telnet_process (void) {
_i16 rxLen;
_i16 maxLen = (telnet_data.rxWindex >= telnet_data.rxRindex) ? (TELNET_RX_BUFFER_SIZE - telnet_data.rxWindex) :
((telnet_data.rxRindex - telnet_data.rxWindex) - 1);
// to avoid an overrrun
maxLen = (telnet_data.rxRindex == 0) ? (maxLen - 1) : maxLen;
if (maxLen > 0) {
if (E_TELNET_RESULT_OK == telnet_recv_text_non_blocking(&telnet_data.rxBuffer[telnet_data.rxWindex], maxLen, &rxLen)) {
// rxWindex must be uint8_t and TELNET_RX_BUFFER_SIZE == 256 so that it wraps around automatically
telnet_data.rxWindex = telnet_data.rxWindex + rxLen;
}
}
}
static int telnet_process_credential (char *credential, _i16 rxLen) {
telnet_data.rxWindex += rxLen;
if (telnet_data.rxWindex >= SERVERS_USER_PASS_LEN_MAX) {
telnet_data.rxWindex = SERVERS_USER_PASS_LEN_MAX;
}
uint8_t *p = telnet_data.rxBuffer + SERVERS_USER_PASS_LEN_MAX;
// if a '\r' is found, or the length exceeds the max username length
if ((p = memchr(telnet_data.rxBuffer, '\r', telnet_data.rxWindex)) || (telnet_data.rxWindex >= SERVERS_USER_PASS_LEN_MAX)) {
uint8_t len = p - telnet_data.rxBuffer;
telnet_data.rxWindex = 0;
if ((len > 0) && (memcmp(credential, telnet_data.rxBuffer, MAX(len, strlen(credential))) == 0)) {
return 1;
}
return -1;
}
return 0;
}
static void telnet_parse_input (uint8_t *str, int16_t *len) {
int16_t b_len = *len;
uint8_t *b_str = str;
for (uint8_t *_str = b_str; _str < b_str + b_len; ) {
if (*_str <= 127) {
if (telnet_data.state == E_TELNET_STE_LOGGED_IN && *_str == user_interrupt_char) {
// raise a keyboard exception
mpexception_keyboard_nlr_jump();
(*len)--;
_str++;
}
else {
*str++ = *_str++;
}
}
else {
// in case we have received an incomplete telnet option, unlikely, but possible
_str += MIN(3, *len);
*len -= MIN(3, *len);
}
}
}
static bool telnet_send_with_retries (int16_t sd, const void *pBuf, int16_t len) {
int32_t retries = 0;
// abort sending if we happen to be within interrupt context
if ((HAL_NVIC_INT_CTRL_REG & HAL_VECTACTIVE_MASK) == 0) {
do {
_i16 result = sl_Send(sd, pBuf, len, 0);
if (result > 0) {
return true;
}
else if (SL_EAGAIN != result) {
return false;
}
HAL_Delay (TELNET_WAIT_TIME_MS);
} while (++retries <= TELNET_TX_RETRIES_MAX);
}
return false;
}
static void telnet_reset_buffer (void) {
// erase any characters present in the current line
memset (telnet_data.rxBuffer, '\b', TELNET_RX_BUFFER_SIZE / 2);
telnet_data.rxWindex = TELNET_RX_BUFFER_SIZE / 2;
// fake an "enter" key pressed to display the prompt
telnet_data.rxBuffer[telnet_data.rxWindex++] = '\r';
}