/*
* Write data from the output queue to the Telnet session.
*/
static void
telnet_write(ndesc_t *nd, telnet_t *tp)
{
if (!nq_empty(tp->t_outq))
{
if (nq_send(tp->t_outq, nd_fd(nd), &tp->t_sblen) == -1)
{
switch (errno)
{
case EWOULDBLOCK:
case EINTR:
case EPROTO:
break;
default:
telnet_disconnect(tp);
return;
}
}
}
if (tp->t_flags & TF_OVFLOUTQ)
{
if (nq_len(tp->t_outq) < TELNET_OUTQ_LOWAT)
{
tp->t_flags &= ~TF_OVFLOUTQ;
nq_puts(tp->t_outq, (u_char *)"*** Truncated. ***\r\n");
}
}
if (tp->t_flags & TF_FLOWC)
{
if (nq_len(tp->t_outq) < TELNET_OUTQ_HIWAT)
{
tp->t_flags &= ~TF_FLOWC;
nd_enable(nd, ND_C);
}
}
if (!nq_empty(tp->t_outq))
return;
nq_init(tp->t_outq);
tp->t_flags |= TF_ENABW;
nd_disable(nd, ND_W);
}
/*
* Process an Erase Character/Backspace/Delete.
*/
static INLINE void
telnet_ec(telnet_t *tp)
{
if (tp->t_flags & (TF_OVFLCANQ | TF_SYNCH))
return;
if (!nq_empty(tp->t_canq))
nq_unputc(tp->t_canq);
}
/*
* Write data from the output queue to the Telnet session.
*/
static void
telnet_write(ndesc_t *nd, telnet_t *tp)
{
if (!nq_empty(tp->t_outq))
{
if (nq_send(tp->t_outq, nd_fd(nd), &tp->t_sblen) == -1)
{
switch (errno)
{
case EWOULDBLOCK:
case EINTR:
case EPROTO:
break;
default:
telnet_disconnect(tp);
return;
}
}
}
if (tp->t_flags & TF_OVFLOUTQ)
{
if (nq_len(tp->t_outq) < TELNET_OUTQ_LOWAT)
{
tp->t_flags &= ~TF_OVFLOUTQ;
if (tp->t_flags & (TF_INPUT|TF_DISCONNECT) &&
!tp->task) /* Reenable command processing */
tp->task = create_task(telnet_interactive, tp);
}
}
if (!nq_empty(tp->t_outq))
return;
nq_init(tp->t_outq);
nd_disable(nd, ND_W);
}
/*
* Flush the output queue.
*/
static void
telnet_flush(telnet_t *tp)
{
if (!nq_empty(tp->t_outq))
nq_send(tp->t_outq, nd_fd(tp->t_nd), &tp->t_sblen);
}
/*
* Perform Telnet protocol processing, copying the contents of the raw input
* queue to the canonical queue.
*/
static void
telnet_input(telnet_t *tp)
{
u_char c;
while (!nq_empty(tp->t_rawq))
{
c = nq_getc(tp->t_rawq);
switch (tp->t_state)
{
case TS_DATA:
switch (c)
{
case NUL:
break;
case BS:
telnet_ec(tp);
break;
case LF:
telnet_eol(tp);
return;
case CR:
tp->t_state = TS_CR;
break;
case DEL:
telnet_ec(tp);
break;
case IAC:
tp->t_state = TS_IAC;
break;
default:
telnet_canq_putc(tp, c);
break;
}
break;
case TS_CR:
telnet_eol(tp);
tp->t_state = TS_DATA;
return;
case TS_IAC:
tp->t_state = TS_DATA;
switch (c)
{
case DM:
telnet_dm(tp);
break;
case AYT:
telnet_ayt(tp);
break;
case EC:
telnet_ec(tp);
break;
case EL:
telnet_el(tp);
break;
case SB:
tp->t_state = TS_IAC_SB;
break;
case WILL:
tp->t_state = TS_IAC_WILL;
break;
case WONT:
tp->t_state = TS_IAC_WONT;
break;
case DO:
tp->t_state = TS_IAC_DO;
break;
case DONT:
tp->t_state = TS_IAC_DONT;
break;
case IAC:
telnet_canq_putc(tp, c);
break;
}
break;
case TS_IAC_SB:
telnet_sb(tp, c);
tp->t_state = TS_IAC_SB_DATA;
break;
case TS_IAC_SB_DATA:
switch (c)
{
case IAC:
tp->t_state = TS_IAC_SB_IAC;
break;
default:
telnet_optq_putc(tp, c);
break;
}
break;
case TS_IAC_SB_IAC:
tp->t_state = TS_IAC_SB_DATA;
switch (c)
{
case SE:
telnet_se(tp);
tp->t_state = TS_DATA;
break;
case IAC:
telnet_optq_putc(tp, c);
break;
}
break;
case TS_IAC_WILL:
telnet_will(tp, c);
tp->t_state = TS_DATA;
break;
case TS_IAC_WONT:
telnet_wont(tp, c);
tp->t_state = TS_DATA;
break;
case TS_IAC_DO:
telnet_do(tp, c);
tp->t_state = TS_DATA;
break;
case TS_IAC_DONT:
telnet_dont(tp, c);
tp->t_state = TS_DATA;
break;
}
}
if ((tp->t_flags & (TF_SGA | TF_GA)) == 0)
{
if (nq_avail(tp->t_outq) >= 2)
{
tp->t_flags |= TF_GA;
telnet_send_ga(tp);
}
}
nq_init(tp->t_rawq);
}