/* send complete subnegotiation */
void telnet_subnegotiation(telnet_t *telnet, unsigned char telopt,
const char *buffer, size_t size) {
unsigned char bytes[5];
bytes[0] = TELNET_IAC;
bytes[1] = TELNET_SB;
bytes[2] = telopt;
bytes[3] = TELNET_IAC;
bytes[4] = TELNET_SE;
_sendu(telnet, bytes, 3);
telnet_send(telnet, buffer, size);
_sendu(telnet, bytes + 3, 2);
#if defined(HAVE_ZLIB)
/* if we're a proxy and we just sent the COMPRESS2 marker, we must
* make sure all further data is compressed if not already.
*/
if (telnet->flags & TELNET_FLAG_PROXY &&
telopt == TELNET_TELOPT_COMPRESS2) {
telnet_event_t ev;
if (_init_zlib(telnet, 1, 1) != TELNET_EOK)
return;
/* notify app that compression was enabled */
ev.type = TELNET_EV_COMPRESS;
ev.compress.state = 1;
telnet->eh(telnet, &ev, telnet->ud);
}
#endif /* defined(HAVE_ZLIB) */
}
/* send complete subnegotiation */
void telnet_subnegotiation(telnet_t *telnet, unsigned char telopt,
const char *buffer, size_t size)
{
unsigned char bytes[5];
bytes[0] = TELNET_IAC;
bytes[1] = TELNET_SB;
bytes[2] = telopt;
bytes[3] = TELNET_IAC;
bytes[4] = TELNET_SE;
_sendu(telnet, bytes, 3);
telnet_send(telnet, buffer, size);
_sendu(telnet, bytes + 3, 2);
}
/* send TERMINAL-TYPE IS command */
void telnet_ttype_is(telnet_t *telnet, const char* ttype) {
static const unsigned char IS[] = { TELNET_IAC, TELNET_SB,
TELNET_TELOPT_TTYPE, TELNET_TTYPE_IS };
_sendu(telnet, IS, sizeof(IS));
_send(telnet, ttype, strlen(ttype));
telnet_finish_sb(telnet);
}
/* send subnegotiation header */
void telnet_begin_sb(telnet_t *telnet, unsigned char telopt) {
unsigned char sb[3];
sb[0] = TELNET_IAC;
sb[1] = TELNET_SB;
sb[2] = telopt;
_sendu(telnet, sb, 3);
}
/* send an iac command */
void telnet_iac(telnet_t *telnet, unsigned char cmd)
{
unsigned char bytes[2];
bytes[0] = TELNET_IAC;
bytes[1] = cmd;
_sendu(telnet, bytes, 2);
}
/* send negotiation bytes */
static INLINE void _send_negotiate(telnet_t *telnet, unsigned char cmd,
unsigned char telopt) {
unsigned char bytes[3];
bytes[0] = TELNET_IAC;
bytes[1] = cmd;
bytes[2] = telopt;
_sendu(telnet, bytes, 3);
}
/* send TERMINAL-TYPE SEND command */
void telnet_ttype_send(telnet_t *telnet) {
static const unsigned char SEND[] = { TELNET_IAC, TELNET_SB,
TELNET_TELOPT_TTYPE, TELNET_TTYPE_SEND, TELNET_IAC, TELNET_SE };
_sendu(telnet, SEND, sizeof(SEND));
}
/* send negotiation */
void telnet_negotiate(telnet_t *telnet, unsigned char cmd,
unsigned char telopt) {
telnet_rfc1143_t q;
/* if we're in proxy mode, just send it now */
if (telnet->flags & TELNET_FLAG_PROXY) {
unsigned char bytes[3];
bytes[0] = TELNET_IAC;
bytes[1] = cmd;
bytes[2] = telopt;
_sendu(telnet, bytes, 3);
return;
}
/* get current option states */
q = _get_rfc1143(telnet, telopt);
switch (cmd) {
/* advertise willingess to support an option */
case TELNET_WILL:
switch (Q_US(q)) {
case Q_NO:
_set_rfc1143(telnet, telopt, Q_WANTYES, Q_HIM(q));
_send_negotiate(telnet, TELNET_WILL, telopt);
break;
case Q_WANTNO:
_set_rfc1143(telnet, telopt, Q_WANTNO_OP, Q_HIM(q));
break;
case Q_WANTYES_OP:
_set_rfc1143(telnet, telopt, Q_WANTYES, Q_HIM(q));
break;
}
break;
/* force turn-off of locally enabled option */
case TELNET_WONT:
switch (Q_US(q)) {
case Q_YES:
_set_rfc1143(telnet, telopt, Q_WANTNO, Q_HIM(q));
_send_negotiate(telnet, TELNET_WONT, telopt);
break;
case Q_WANTYES:
_set_rfc1143(telnet, telopt, Q_WANTYES_OP, Q_HIM(q));
break;
case Q_WANTNO_OP:
_set_rfc1143(telnet, telopt, Q_WANTNO, Q_HIM(q));
break;
}
break;
/* ask remote end to enable an option */
case TELNET_DO:
switch (Q_HIM(q)) {
case Q_NO:
_set_rfc1143(telnet, telopt, Q_US(q), Q_WANTYES);
_send_negotiate(telnet, TELNET_DO, telopt);
break;
case Q_WANTNO:
_set_rfc1143(telnet, telopt, Q_US(q), Q_WANTNO_OP);
break;
case Q_WANTYES_OP:
_set_rfc1143(telnet, telopt, Q_US(q), Q_WANTYES);
break;
}
break;
/* demand remote end disable an option */
case TELNET_DONT:
switch (Q_HIM(q)) {
case Q_YES:
_set_rfc1143(telnet, telopt, Q_US(q), Q_WANTNO);
_send_negotiate(telnet, TELNET_DONT, telopt);
break;
case Q_WANTYES:
_set_rfc1143(telnet, telopt, Q_US(q), Q_WANTYES_OP);
break;
case Q_WANTNO_OP:
_set_rfc1143(telnet, telopt, Q_US(q), Q_WANTNO);
break;
}
break;
}
}
/* send negotiation bytes */
static INLINE void _send_negotiate(telnet_t *telnet, unsigned char cmd,
unsigned char telopt) {
const unsigned char bytes[3] = { TELNET_IAC, cmd, telopt };
_sendu(telnet, bytes, 3);
}
/* send subnegotiation header */
void telnet_begin_sb(telnet_t *telnet, unsigned char telopt) {
const unsigned char sb[3] = { TELNET_IAC, TELNET_SB, telopt };
_sendu(telnet, sb, 3);
}
/* send an iac command */
void telnet_iac(telnet_t *telnet, unsigned char cmd) {
const unsigned char bytes[2] = { TELNET_IAC, cmd };
_sendu(telnet, bytes, 2);
}