From 287d03ac26ae79baa51a55732ac82e221171f422 Mon Sep 17 00:00:00 2001
From: Rob Swindell <rob@synchro.net>
Date: Tue, 10 May 2022 17:04:36 -0700
Subject: [PATCH] Set Telnet-server options (e.g. will echo) in answer()
---
src/vdmodem/vdmodem.c | 326 ++++++++++++++++++++++--------------------
1 file changed, 167 insertions(+), 159 deletions(-)
diff --git a/src/vdmodem/vdmodem.c b/src/vdmodem/vdmodem.c
index 4fbbc966f4..93d1f29f0e 100644
--- a/src/vdmodem/vdmodem.c
+++ b/src/vdmodem/vdmodem.c
@@ -220,7 +220,6 @@ char* connect_result(struct modem* modem)
char* connected(struct modem* modem)
{
- ZERO_VAR(telnet);
modem->online = true;
modem->ringing = false;
ResetEvent(hungup_event);
@@ -269,6 +268,164 @@ int address_family()
return PF_UNSPEC;
}
+int putcom(char* buf, size_t len)
+{
+ return send(sock, buf, len, /* flags: */0);
+}
+
+static void send_telnet_cmd(uchar cmd, uchar opt)
+{
+ char buf[16];
+
+ if(cmd<TELNET_WILL) {
+ dprintf("TELNET TX: %s"
+ ,telnet_cmd_desc(cmd));
+ sprintf(buf,"%c%c",TELNET_IAC,cmd);
+ putcom(buf,2);
+ } else {
+ dprintf("TELNET TX: %s %s"
+ ,telnet_cmd_desc(cmd), telnet_opt_desc(opt));
+ sprintf(buf,"%c%c%c",TELNET_IAC,cmd,opt);
+ putcom(buf,3);
+ }
+}
+
+void request_telnet_opt(uchar cmd, uchar opt)
+{
+ if(cmd==TELNET_DO || cmd==TELNET_DONT) { /* remote option */
+ if(telnet.remote_option[opt]==telnet_opt_ack(cmd))
+ return; /* already set in this mode, do nothing */
+ telnet.remote_option[opt]=telnet_opt_ack(cmd);
+ } else { /* local option */
+ if(telnet.local_option[opt]==telnet_opt_ack(cmd))
+ return; /* already set in this mode, do nothing */
+ telnet.local_option[opt]=telnet_opt_ack(cmd);
+ }
+ send_telnet_cmd(cmd,opt);
+}
+
+BYTE* telnet_interpret(BYTE* inbuf, size_t inlen, BYTE* outbuf, size_t *outlen)
+{
+ BYTE command;
+ BYTE option;
+ BYTE* first_cr=NULL;
+ BYTE* first_int=NULL;
+ size_t i;
+
+ if(inlen<1) {
+ *outlen=0;
+ return(inbuf); /* no length? No interpretation */
+ }
+
+ first_int=(BYTE*)memchr(inbuf, TELNET_IAC, inlen);
+ if(telnet.remote_option[TELNET_BINARY_TX]!=TELNET_WILL) {
+ first_cr=(BYTE*)memchr(inbuf, '\r', inlen);
+ if(first_cr) {
+ if(first_int==NULL || first_cr < first_int)
+ first_int=first_cr;
+ }
+ }
+
+ if(telnet.cmdlen==0 && first_int==NULL) {
+ *outlen=inlen;
+ return(inbuf); /* no interpretation needed */
+ }
+
+ if(telnet.cmdlen==0 /* If we haven't returned and telnet.cmdlen==0 then first_int is not NULL */ ) {
+ *outlen=first_int-inbuf;
+ memcpy(outbuf, inbuf, *outlen);
+ } else
+ *outlen=0;
+
+ for(i=*outlen;i<inlen;i++) {
+ if(telnet.remote_option[TELNET_BINARY_TX]!=TELNET_WILL) {
+ if(telnet.cmdlen==1 && telnet.cmd[0]=='\r') {
+ outbuf[(*outlen)++]='\r';
+ if(inbuf[i]!=0 && inbuf[i]!=TELNET_IAC)
+ outbuf[(*outlen)++]=inbuf[i];
+ telnet.cmdlen=0;
+ if(inbuf[i]!=TELNET_IAC)
+ continue;
+ }
+ if(inbuf[i]=='\r' && telnet.cmdlen==0) {
+ telnet.cmd[telnet.cmdlen++]='\r';
+ continue;
+ }
+ }
+
+ if(inbuf[i]==TELNET_IAC && telnet.cmdlen==1) { /* escaped 255 */
+ telnet.cmdlen=0;
+ outbuf[(*outlen)++]=TELNET_IAC;
+ continue;
+ }
+ if(inbuf[i]==TELNET_IAC || telnet.cmdlen) {
+
+ if(telnet.cmdlen<sizeof(telnet.cmd))
+ telnet.cmd[telnet.cmdlen++]=inbuf[i];
+
+ command = telnet.cmd[1];
+ option = telnet.cmd[2];
+
+ if(telnet.cmdlen>=2 && command==TELNET_SB) {
+ if(inbuf[i]==TELNET_SE
+ && telnet.cmd[telnet.cmdlen-2]==TELNET_IAC) {
+ telnet.cmdlen=0;
+ }
+ }
+ else if(telnet.cmdlen==2 && inbuf[i]<TELNET_WILL) {
+ telnet.cmdlen=0;
+ }
+ else if(telnet.cmdlen>=3) { /* telnet option negotiation */
+
+ dprintf("TELNET RX: %s %s"
+ ,telnet_cmd_desc(command),telnet_opt_desc(option));
+
+ if(command==TELNET_DO || command==TELNET_DONT) { /* local options */
+ if(telnet.local_option[option]!=command) {
+ switch(option) {
+ case TELNET_BINARY_TX:
+ case TELNET_ECHO:
+ case TELNET_TERM_TYPE:
+ case TELNET_SUP_GA:
+ case TELNET_NEGOTIATE_WINDOW_SIZE:
+ telnet.local_option[option]=command;
+ send_telnet_cmd(telnet_opt_ack(command),option);
+ break;
+ default: /* unsupported local options */
+ if(command==TELNET_DO) /* NAK */
+ send_telnet_cmd(telnet_opt_nak(command),option);
+ break;
+ }
+ }
+ } else { /* WILL/WONT (remote options) */
+ if(telnet.remote_option[option]!=command) {
+
+ switch(option) {
+ case TELNET_BINARY_TX:
+ case TELNET_ECHO:
+ case TELNET_TERM_TYPE:
+ case TELNET_SUP_GA:
+ case TELNET_NEGOTIATE_WINDOW_SIZE:
+ telnet.remote_option[option]=command;
+ send_telnet_cmd(telnet_opt_ack(command),option);
+ break;
+ default: /* unsupported remote options */
+ if(command==TELNET_WILL) /* NAK */
+ send_telnet_cmd(telnet_opt_nak(command),option);
+ break;
+ }
+ }
+ }
+
+ telnet.cmdlen=0;
+
+ }
+ } else
+ outbuf[(*outlen)++]=inbuf[i];
+ }
+ return(outbuf);
+}
+
// Significant portions copies from syncterm/conn.c
char* dial(struct modem* modem, const char* number)
{
@@ -386,6 +543,7 @@ connected:
dprintf("%s %d connected!", __FILE__, __LINE__);
int keepalives = TRUE;
setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void*)&keepalives, sizeof(keepalives));
+ ZERO_VAR(telnet);
return connected(modem);
}
@@ -409,6 +567,14 @@ char* answer(struct modem* modem)
}
char tmp[256];
dprintf("Connection accepted from TCP port %hu at %s", inet_addrport(&addr), inet_addrtop(&addr, tmp, sizeof(tmp)));
+
+ if(mode == TELNET) {
+ ZERO_VAR(telnet);
+ /* Disable Telnet Terminal Echo */
+ request_telnet_opt(TELNET_WILL,TELNET_ECHO);
+ /* Will suppress Go Ahead */
+ request_telnet_opt(TELNET_WILL,TELNET_SUP_GA);
+ }
return connected(modem);
}
@@ -650,164 +816,6 @@ void listen_thread(void* arg)
}
}
-int putcom(char* buf, size_t len)
-{
- return send(sock, buf, len, /* flags: */0);
-}
-
-static void send_telnet_cmd(uchar cmd, uchar opt)
-{
- char buf[16];
-
- if(cmd<TELNET_WILL) {
- dprintf("TELNET TX: %s"
- ,telnet_cmd_desc(cmd));
- sprintf(buf,"%c%c",TELNET_IAC,cmd);
- putcom(buf,2);
- } else {
- dprintf("TELNET TX: %s %s"
- ,telnet_cmd_desc(cmd), telnet_opt_desc(opt));
- sprintf(buf,"%c%c%c",TELNET_IAC,cmd,opt);
- putcom(buf,3);
- }
-}
-
-void request_telnet_opt(uchar cmd, uchar opt)
-{
- if(cmd==TELNET_DO || cmd==TELNET_DONT) { /* remote option */
- if(telnet.remote_option[opt]==telnet_opt_ack(cmd))
- return; /* already set in this mode, do nothing */
- telnet.remote_option[opt]=telnet_opt_ack(cmd);
- } else { /* local option */
- if(telnet.local_option[opt]==telnet_opt_ack(cmd))
- return; /* already set in this mode, do nothing */
- telnet.local_option[opt]=telnet_opt_ack(cmd);
- }
- send_telnet_cmd(cmd,opt);
-}
-
-BYTE* telnet_interpret(BYTE* inbuf, size_t inlen, BYTE* outbuf, size_t *outlen)
-{
- BYTE command;
- BYTE option;
- BYTE* first_cr=NULL;
- BYTE* first_int=NULL;
- size_t i;
-
- if(inlen<1) {
- *outlen=0;
- return(inbuf); /* no length? No interpretation */
- }
-
- first_int=(BYTE*)memchr(inbuf, TELNET_IAC, inlen);
- if(telnet.remote_option[TELNET_BINARY_TX]!=TELNET_WILL) {
- first_cr=(BYTE*)memchr(inbuf, '\r', inlen);
- if(first_cr) {
- if(first_int==NULL || first_cr < first_int)
- first_int=first_cr;
- }
- }
-
- if(telnet.cmdlen==0 && first_int==NULL) {
- *outlen=inlen;
- return(inbuf); /* no interpretation needed */
- }
-
- if(telnet.cmdlen==0 /* If we haven't returned and telnet.cmdlen==0 then first_int is not NULL */ ) {
- *outlen=first_int-inbuf;
- memcpy(outbuf, inbuf, *outlen);
- } else
- *outlen=0;
-
- for(i=*outlen;i<inlen;i++) {
- if(telnet.remote_option[TELNET_BINARY_TX]!=TELNET_WILL) {
- if(telnet.cmdlen==1 && telnet.cmd[0]=='\r') {
- outbuf[(*outlen)++]='\r';
- if(inbuf[i]!=0 && inbuf[i]!=TELNET_IAC)
- outbuf[(*outlen)++]=inbuf[i];
- telnet.cmdlen=0;
- if(inbuf[i]!=TELNET_IAC)
- continue;
- }
- if(inbuf[i]=='\r' && telnet.cmdlen==0) {
- telnet.cmd[telnet.cmdlen++]='\r';
- continue;
- }
- }
-
- if(inbuf[i]==TELNET_IAC && telnet.cmdlen==1) { /* escaped 255 */
- telnet.cmdlen=0;
- outbuf[(*outlen)++]=TELNET_IAC;
- continue;
- }
- if(inbuf[i]==TELNET_IAC || telnet.cmdlen) {
-
- if(telnet.cmdlen<sizeof(telnet.cmd))
- telnet.cmd[telnet.cmdlen++]=inbuf[i];
-
- command = telnet.cmd[1];
- option = telnet.cmd[2];
-
- if(telnet.cmdlen>=2 && command==TELNET_SB) {
- if(inbuf[i]==TELNET_SE
- && telnet.cmd[telnet.cmdlen-2]==TELNET_IAC) {
- telnet.cmdlen=0;
- }
- }
- else if(telnet.cmdlen==2 && inbuf[i]<TELNET_WILL) {
- telnet.cmdlen=0;
- }
- else if(telnet.cmdlen>=3) { /* telnet option negotiation */
-
- dprintf("TELNET RX: %s %s"
- ,telnet_cmd_desc(command),telnet_opt_desc(option));
-
- if(command==TELNET_DO || command==TELNET_DONT) { /* local options */
- if(telnet.local_option[option]!=command) {
- switch(option) {
- case TELNET_BINARY_TX:
- case TELNET_ECHO:
- case TELNET_TERM_TYPE:
- case TELNET_SUP_GA:
- case TELNET_NEGOTIATE_WINDOW_SIZE:
- telnet.local_option[option]=command;
- send_telnet_cmd(telnet_opt_ack(command),option);
- break;
- default: /* unsupported local options */
- if(command==TELNET_DO) /* NAK */
- send_telnet_cmd(telnet_opt_nak(command),option);
- break;
- }
- }
- } else { /* WILL/WONT (remote options) */
- if(telnet.remote_option[option]!=command) {
-
- switch(option) {
- case TELNET_BINARY_TX:
- case TELNET_ECHO:
- case TELNET_TERM_TYPE:
- case TELNET_SUP_GA:
- case TELNET_NEGOTIATE_WINDOW_SIZE:
- telnet.remote_option[option]=command;
- send_telnet_cmd(telnet_opt_ack(command),option);
- break;
- default: /* unsupported remote options */
- if(command==TELNET_WILL) /* NAK */
- send_telnet_cmd(telnet_opt_nak(command),option);
- break;
- }
- }
- }
-
- telnet.cmdlen=0;
-
- }
- } else
- outbuf[(*outlen)++]=inbuf[i];
- }
- return(outbuf);
-}
-
int main(int argc, char** argv)
{
int argn = 1;
--
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