www.pudn.com > UIP09_ADSP-BF537_Blackfin_org.zip > telnetd.c
/**
* \addtogroup exampleapps
* @{
*/
/**
* \defgroup telnetd Telnet server
* @{
*
* The uIP telnet server provides a command based interface to uIP. It
* allows using the "telnet" application to access uIP, and implements
* the required telnet option negotiation.
*
* The code is structured in a way which makes it possible to add
* commands without having to rewrite the main telnet code. The main
* telnet code calls two callback functions, telnetd_connected() and
* telnetd_input(), when a telnet connection has been established and
* when a line of text arrives on a telnet connection. These two
* functions can be implemented in a way which suits the particular
* application or environment in which the uIP system is intended to
* be run.
*
* The uIP distribution contains an example telnet shell
* implementation that provides a basic set of commands.
*/
/**
* \file
* Implementation of the Telnet server.
* \author Adam Dunkels
*/
/*
* Copyright (c) 2003, Adam Dunkels.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This file is part of the uIP TCP/IP stack.
*
* $Id: telnetd.c,v 1.1.2.2 2003/10/07 13:47:50 adam Exp $
*
*/
#include "uip.h"
#include "memb.h"
#include "telnetd.h"
#include
#define ISO_nl 0x0a
#define ISO_cr 0x0d
MEMB(linemem, TELNETD_LINELEN, TELNETD_NUMLINES);
static u8_t i;
#define STATE_NORMAL 0
#define STATE_IAC 1
#define STATE_WILL 2
#define STATE_WONT 3
#define STATE_DO 4
#define STATE_DONT 5
#define STATE_CLOSE 6
#define TELNET_IAC 255
#define TELNET_WILL 251
#define TELNET_WONT 252
#define TELNET_DO 253
#define TELNET_DONT 254
/*-----------------------------------------------------------------------------------*/
static char *
alloc_line(void)
{
return memb_alloc(&linemem);
}
/*-----------------------------------------------------------------------------------*/
static void
dealloc_line(char *line)
{
memb_free(&linemem, line);
}
/*-----------------------------------------------------------------------------------*/
static void
sendline(struct telnetd_state *s, char *line)
{
static unsigned int i;
for(i = 0; i < TELNETD_NUMLINES; ++i) {
if(s->lines[i] == NULL) {
s->lines[i] = line;
break;
}
}
if(i == TELNETD_NUMLINES) {
dealloc_line(line);
}
}
/*-----------------------------------------------------------------------------------*/
/**
* Close a telnet session.
*
* This function can be called from a telnet command in order to close
* the connection.
*
* \param s The connection which is to be closed.
*
*/
/*-----------------------------------------------------------------------------------*/
void
telnetd_close(struct telnetd_state *s)
{
s->state = STATE_CLOSE;
}
/*-----------------------------------------------------------------------------------*/
/**
* Print a prompt on a telnet connection.
*
* This function can be called by the telnet command shell in order to
* print out a command prompt.
*
* \param s A telnet connection.
*
* \param str The command prompt.
*
*/
/*-----------------------------------------------------------------------------------*/
void
telnetd_prompt(struct telnetd_state *s, char *str)
{
char *line;
line = alloc_line();
if(line != NULL) {
strncpy(line, str, TELNETD_LINELEN);
sendline(s, line);
}
}
/*-----------------------------------------------------------------------------------*/
/**
* Print out a string on a telnet connection.
*
* This function can be called from a telnet command parser in order
* to print out a string of text on the connection. The two strings
* given as arguments to the function will be concatenated, a carrige
* return and a new line character will be added, and the line is
* sent.
*
* \param s The telnet connection.
*
* \param str1 The first string.
*
* \param str2 The second string.
*
*/
/*-----------------------------------------------------------------------------------*/
void
telnetd_output(struct telnetd_state *s, char *str1, char *str2)
{
static unsigned len;
char *line;
line = alloc_line();
if(line != NULL) {
len = strlen(str1);
strncpy(line, str1, TELNETD_LINELEN);
if(len < TELNETD_LINELEN) {
strncpy(line + len, str2, TELNETD_LINELEN - len);
}
len = strlen(line);
if(len < TELNETD_LINELEN - 2) {
line[len] = ISO_cr;
line[len+1] = ISO_nl;
line[len+2] = 0;
}
sendline(s, line);
}
}
/*-----------------------------------------------------------------------------------*/
/**
* Initialize the telnet server.
*
* This function will perform the necessary initializations and start
* listening on TCP port 23.
*/
/*-----------------------------------------------------------------------------------*/
void
telnetd_init(void)
{
memb_init(&linemem);
uip_listen(HTONS(23));
}
/*-----------------------------------------------------------------------------------*/
static void
acked(struct telnetd_state *s)
{
dealloc_line(s->lines[0]);
for(i = 1; i < TELNETD_NUMLINES; ++i) {
s->lines[i - 1] = s->lines[i];
}
}
/*-----------------------------------------------------------------------------------*/
static void
senddata(struct telnetd_state *s)
{
if(s->lines[0] != NULL) {
uip_send(s->lines[0], strlen(s->lines[0]));
}
}
/*-----------------------------------------------------------------------------------*/
static void
getchar(struct telnetd_state *s, u8_t c)
{
if(c == ISO_cr) {
return;
}
s->buf[(int)s->bufptr] = c;
if(s->buf[(int)s->bufptr] == ISO_nl ||
s->bufptr == sizeof(s->buf) - 1) {
if(s->bufptr > 0) {
s->buf[(int)s->bufptr] = 0;
}
telnetd_input(s, s->buf);
s->bufptr = 0;
} else {
++s->bufptr;
}
}
/*-----------------------------------------------------------------------------------*/
static void
sendopt(struct telnetd_state *s, u8_t option, u8_t value)
{
char *line;
line = alloc_line();
if(line != NULL) {
line[0] = TELNET_IAC;
line[1] = option;
line[2] = value;
line[3] = 0;
sendline(s, line);
}
}
/*-----------------------------------------------------------------------------------*/
static void
newdata(struct telnetd_state *s)
{
u16_t len;
u8_t c;
len = uip_datalen();
while(len > 0 && s->bufptr < sizeof(s->buf)) {
c = *uip_appdata;
++uip_appdata;
--len;
switch(s->state) {
case STATE_IAC:
if(c == TELNET_IAC) {
getchar(s, c);
s->state = STATE_NORMAL;
} else {
switch(c) {
case TELNET_WILL:
s->state = STATE_WILL;
break;
case TELNET_WONT:
s->state = STATE_WONT;
break;
case TELNET_DO:
s->state = STATE_DO;
break;
case TELNET_DONT:
s->state = STATE_DONT;
break;
default:
s->state = STATE_NORMAL;
break;
}
}
break;
case STATE_WILL:
/* Reply with a DONT */
sendopt(s, TELNET_DONT, c);
s->state = STATE_NORMAL;
break;
case STATE_WONT:
/* Reply with a DONT */
sendopt(s, TELNET_DONT, c);
s->state = STATE_NORMAL;
break;
case STATE_DO:
/* Reply with a WONT */
sendopt(s, TELNET_WONT, c);
s->state = STATE_NORMAL;
break;
case STATE_DONT:
/* Reply with a WONT */
sendopt(s, TELNET_WONT, c);
s->state = STATE_NORMAL;
break;
case STATE_NORMAL:
if(c == TELNET_IAC) {
s->state = STATE_IAC;
} else {
getchar(s, c);
}
break;
}
}
}
/*-----------------------------------------------------------------------------------*/
void
telnetd_app(void)
{
struct telnetd_state *s;
s = (struct telnetd_state *)uip_conn->appstate;
if(uip_connected()) {
for(i = 0; i < TELNETD_NUMLINES; ++i) {
s->lines[i] = NULL;
}
s->bufptr = 0;
s->state = STATE_NORMAL;
telnetd_connected(s);
senddata(s);
return;
}
if(s->state == STATE_CLOSE) {
s->state = STATE_NORMAL;
uip_close();
return;
}
if(uip_closed()) {
telnetd_output(s, "Connection closed", "");
}
if(uip_aborted()) {
telnetd_output(s, "Connection reset", "");
}
if(uip_timedout()) {
telnetd_output(s, "Connection timed out", "");
}
if(uip_acked()) {
acked(s);
}
if(uip_newdata()) {
newdata(s);
}
if(uip_rexmit() ||
uip_newdata() ||
uip_acked()) {
senddata(s);
} else if(uip_poll()) {
senddata(s);
}
}
/*-----------------------------------------------------------------------------------*/