/*---------------------------------------------------------------------------*/
static void
newdata(void)
{
u16_t len;
u8_t c;
char *dataptr;
len = uip_datalen();
dataptr = (char *)uip_appdata;
while(len > 0 && s.bufptr < sizeof(s.buf)) {
c = *dataptr;
++dataptr;
--len;
switch(s.state) {
case STATE_IAC:
if(c == TELNET_IAC) {
get_char(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(TELNET_DONT, c);
s.state = STATE_NORMAL;
break;
case STATE_WONT:
/* Reply with a DONT */
sendopt(TELNET_DONT, c);
s.state = STATE_NORMAL;
break;
case STATE_DO:
/* Reply with a WONT */
sendopt(TELNET_WONT, c);
s.state = STATE_NORMAL;
break;
case STATE_DONT:
/* Reply with a WONT */
sendopt(TELNET_WONT, c);
s.state = STATE_NORMAL;
break;
case STATE_NORMAL:
if(c == TELNET_IAC) {
s.state = STATE_IAC;
} else {
get_char(c);
}
break;
}
}
}
/*---------------------------------------------------------------------------*/
static void
newdata(void)
{
u16_t len;
u8_t c;
uint8_t *ptr;
len = uip_datalen();
PRINTF("newdata len %d '%.*s'\n", len, len, (char *)uip_appdata);
ptr = uip_appdata;
while(len > 0 && s.bufptr < sizeof(s.buf)) {
c = *ptr;
PRINTF("newdata char '%c' %d %d state %d\n", c, c, len, s.state);
++ptr;
--len;
switch(s.state) {
case STATE_IAC:
if(c == TELNET_IAC) {
get_char(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(TELNET_DONT, c);
s.state = STATE_NORMAL;
break;
case STATE_WONT:
/* Reply with a DONT */
sendopt(TELNET_DONT, c);
s.state = STATE_NORMAL;
break;
case STATE_DO:
/* Reply with a WONT */
sendopt(TELNET_WONT, c);
s.state = STATE_NORMAL;
break;
case STATE_DONT:
/* Reply with a WONT */
sendopt(TELNET_WONT, c);
s.state = STATE_NORMAL;
break;
case STATE_NORMAL:
if(c == TELNET_IAC) {
s.state = STATE_IAC;
} else {
get_char(c);
}
break;
}
}
}
/*
* read a maximum of size chars from remote host
* using the telnet protocol. return chars read.
*/
int tcp_read __P3 (int,fd, char *,buffer, int,maxsize)
{
char state = CONN_LIST(fd).state;
int i;
static byte subopt[MAX_SUBOPT];
static int subchars;
byte *p, *s, *linestart;
while ((i = read(fd, buffer, maxsize)) < 0 && errno == EINTR)
;
if (i == 0) {
CONN_LIST(fd).state = NORMAL;
tcp_close(NULL);
return 0;
}
if (i < 0) {
errmsg("read from socket");
return 0;
}
/*
* scan through the buffer,
* interpret telnet protocol escapes and MUME MPI messages
*/
for (s = p = linestart = (byte *)buffer; i; s++, i--) {
switch (state) {
case NORMAL:
case ALTNORMAL:
case GOT_R:
case GOT_N:
/*
* Some servers like to send NULs and other funny chars.
* Clean up as much as possible.
*/
switch (*s) {
case IAC:
state = GOTIAC;
break;
case '\r':
/* start counting \r, unless just got \n */
if (state == NORMAL || state == ALTNORMAL) {
/*
* ALTNORMAL is safe here: \r cannot be in MPI header,
* and any previous MPI header has already been rejected
*/
state = GOT_R;
} else if (state == GOT_N)
/* after \n\r, we forbid MPI messages */
state = ALTNORMAL;
break;
case '\n':
state = GOT_N;
*p++ = *s;
linestart = p;
break;
case '\0':
/* skip NULs */
break;
default:
/* first, flush any missing \r */
if (state == GOT_R)
*p++ = '\r';
*p++ = *s;
/* check for MUME MPI messages: */
if (p - linestart == MPILEN && !memcmp(linestart, MPI, MPILEN)) {
if (!(CONN_LIST(fd).flags & IDEDITOR)) {
PRINTF("#warning: MPI message received without #request editor!\n");
} else if (state == ALTNORMAL) {
/* no MPI messages after \n\r */
PRINTF("#warning: MPI attack?\n");
} else {
subchars = process_message((char*)s+1, i-1);
/* no +MPILEN here, as it was already processed. */
s += subchars; i-= subchars;
p = linestart;
}
}
if (state != ALTNORMAL)
state = NORMAL;
break;
}
break;
case GOTIAC:
switch (*s) {
case WILL:
state = GOTWILL; break;
case WONT:
state = GOTWONT; break;
case DO:
state = GOTDO; break;
case DONT:
state = GOTDONT; break;
case SB: /* BUG (multiple connections): */
state = GOTSB; /* there is only one subopt buffer */
subchars = 0;
break;
case IAC:
*p++ = IAC;
state = NORMAL;
break;
case GA:
/* I should handle GA as end-of-prompt marker one day */
/* one day has come ;) - Max */
prompt_set_iac((char*)p);
state = NORMAL;
break;
default:
/* ignore the rest of the telnet commands */
#ifdef TELOPTS
tty_printf("[skipped IAC <%d>]\n", *s);
#endif
state = NORMAL;
break;
}
break;
case GOTWILL:
#ifdef TELOPTS
tty_printf("[got WILL %s]\n", TELOPTSTR(*s));
#endif
switch(*s) {
case TELOPT_ECHO:
/* host echoes, turn off echo here
* but only for main connection, since we do not want
* subsidiary connection password entries to block anything
* in the main connection
*/
if (fd == tcp_main_fd)
linemode |= LM_NOECHO;
sendopt(DO, *s);
break;
case TELOPT_SGA:
/* this can't hurt */
linemode |= LM_CHAR;
tty_special_keys();
sendopt(DO, *s);
break;
default:
/* don't accept other options */
sendopt(DONT, *s);
break;
}
state = NORMAL;
break;
case GOTWONT:
#ifdef TELOPTS
tty_printf("[got WONT %s]\n", TELOPTSTR(*s));
#endif
if (*s == TELOPT_ECHO) {
/* host no longer echoes, we do it instead */
linemode &= ~LM_NOECHO;
}
/* accept any WONT */
sendopt(DONT, *s);
state = NORMAL;
break;
case GOTDO:
#ifdef TELOPTS
tty_printf("[got DO %s]\n", TELOPTSTR(*s));
#endif
switch(*s) {
case TELOPT_SGA:
linemode |= LM_CHAR;
tty_special_keys();
/* FALLTHROUGH */
case TELOPT_TTYPE:
sendopt(WILL, *s);
break;
case TELOPT_NAWS:
sendopt(WILL, *s);
tcp_write_tty_size();
break;
default:
/* accept nothing else */
sendopt(WONT, *s);
break;
}
state = NORMAL;
break;
case GOTDONT:
#ifdef TELOPTS
tty_printf("[got DONT %s]\n", TELOPTSTR(*s));
#endif
if (*s == TELOPT_SGA) {
linemode &= ~LM_CHAR;
tty_special_keys();
}
sendopt(WONT, *s);
state = NORMAL;
break;
case GOTSB:
if (*s == IAC) {
state = GOTSBIAC;
} else {
if (subchars < MAX_SUBOPT)
subopt[subchars++] = *s;
}
break;
case GOTSBIAC:
if (*s == IAC) {
if (subchars < MAX_SUBOPT)
subopt[subchars++] = IAC;
state = GOTSB;
} else if (*s == SE) {
subopt[subchars] = '\0';
dosubopt(subopt);
state = NORMAL;
} else {
/* problem! I haven't the foggiest idea of what to do here.
* I'll just ignore it and hope it goes away. */
PRINTF("#telnet: got IAC <%d> instead of IAC SE!\n", (int)*s);
state = NORMAL;
}
break;
}
}
CONN_LIST(fd).state = state;
if (!(CONN_LIST(tcp_fd).flags & SPAWN)) {
log_write(buffer, (char *)p - buffer, 0);
}
return (char *)p - buffer;
}
