Always strip/add parity if it is detected.

README.md

@@ -1,4 +1,5 @@
 This is yet another fork of Jim Brain's tcpser serial to IP modem emulation program.
+
 The original source code can be found here:
 http://www.jbrain.com/pub/linux/serial/
 
@@ -6,12 +7,12 @@ My changes are based upon the rc12 archive dated 11Mar09.
 
 I fixed the bug with being unable to connect to real telnet servers.
 
-I also made the modem routines automatically detect parity and ignore
-it in AT commands and print out modem responses in matching
-parity. Parity is *not* stripped when sending data over the
-connection, which is how a real modem behaves. This may or may not be
-what you want. Some servers will expect an 8 bit connection and may
-not work.
+I also made the modem routines automatically detect parity. If even,
+odd, or mark parity is detected then the telnet connection will be
+limited to 7 bit. Space parity will be treated as 8N1 and will allow
+telnet binary mode.
+
+I also incorporated geneb's changes found at https://github.com/geneb/tcpser
 
 Chris Osborn <fozztexx@fozztexx.com>
 http://insentricity.com

src/bridge.c

@@ -385,7 +385,6 @@ void *run_bridge(void *arg)
         }
         else
           mdm_send_ring(cfg);
-
       }
       else
         mdm_handle_timeout(cfg);

src/line.c

@@ -22,9 +22,13 @@ int line_write(modem_config *cfg, char *data, int len)
   int double_iac = FALSE;
   char text[1024];
   int text_len = 0;
+  int mask = 0x7f;
 
 
-  if (cfg->line_data.is_telnet && cfg->line_data.nvt_data.binary_xmit) {
+  if (cfg->line_data.is_telnet) {
+    if (cfg->line_data.nvt_data.binary_xmit)
+      mask = 0xff;
+    
     retval = 0;
     while (i < len) {
       if (double_iac) {
@@ -38,10 +42,10 @@ int line_write(modem_config *cfg, char *data, int len)
           double_iac = TRUE;
         }
         else {
-          text[text_len++] = data[i++];
+          text[text_len++] = data[i++] & mask;
         }
       }
-      if (text_len == 1024) {
+      if (text_len == sizeof(text_len)) {
         retval = ip_write(cfg->line_data.fd, text, text_len);
         text_len = 0;
       }

src/modem_core.c

@@ -178,14 +178,7 @@ void mdm_write_char(modem_config *cfg, char data)
   mdm_write(cfg, str, 1);
 }
 
-void mdm_write(modem_config *cfg, char data[], int len)
-{
-  if (cfg->allow_transmit == TRUE) {
-    dce_write(cfg, data, len);
-  }
-}
-
-void mdm_write_parity(modem_config *cfg, char *data, int len)
+void mdm_write(modem_config *cfg, char *data, int len)
 {
   unsigned char *buf;
   int i;
@@ -193,18 +186,23 @@ void mdm_write_parity(modem_config *cfg, char *data, int len)
 
   
   if (cfg->allow_transmit == TRUE) {
+    if (cfg->parity) {
       buf = malloc(len);
       memcpy(buf, data, len);
 
       for (i = 0; i < len; i++) {
 	v = buf[i];
 	v = (((v * 0x0101010101010101ULL) & 0x8040201008040201ULL) % 0x1FF) & 1;
+	buf[i] &= 0x7f;
 	buf[i] |= (((cfg->parity >> !v)) & 1) << 7;
       }
     
-    mdm_write(cfg, (char *) buf, len);
+      dce_write(cfg, (char *) buf, len);
       free(buf);
     }
+    else
+      dce_write(cfg, data, len);
+  }
 }
 
 void mdm_send_response(int msg, modem_config *cfg)
@@ -214,17 +212,17 @@ void mdm_send_response(int msg, modem_config *cfg)
 
   LOG(LOG_DEBUG, "Sending %s response to modem", mdm_responses[msg]);
   if (cfg->send_responses == TRUE) {
-    mdm_write_parity(cfg, cfg->crlf, 2);
+    mdm_write(cfg, cfg->crlf, 2);
     if (cfg->text_responses == TRUE) {
       LOG(LOG_ALL, "Sending text response");
-      mdm_write_parity(cfg, mdm_responses[msg], strlen(mdm_responses[msg]));
+      mdm_write(cfg, mdm_responses[msg], strlen(mdm_responses[msg]));
     }
     else {
       LOG(LOG_ALL, "Sending numeric response");
       sprintf(msgID, "%d", msg);
-      mdm_write_parity(cfg, msgID, strlen(msgID));
+      mdm_write(cfg, msgID, strlen(msgID));
     }
-    mdm_write_parity(cfg, cfg->crlf, 2);
+    mdm_write(cfg, cfg->crlf, 2);
   }
 }
 
@@ -389,8 +387,8 @@ int mdm_parse_cmd(modem_config *cfg)
         strncpy(cfg->dialno, cfg->last_dialno, strlen(cfg->last_dialno));
         cfg->dial_type = cfg->dial_type;
         cfg->memory_dial = TRUE;
-        mdm_write_parity(cfg, cfg->crlf, 2);
-        mdm_write_parity(cfg, cfg->dialno, strlen(cfg->dialno));
+        mdm_write(cfg, cfg->crlf, 2);
+        mdm_write(cfg, cfg->dialno, strlen(cfg->dialno));
       }
       else {
         cfg->dialno[0] = 0;
@@ -477,7 +475,7 @@ int mdm_parse_cmd(modem_config *cfg)
       break;
     case AT_CMD_FLAG_QUERY | 'S':
       sprintf(tmp, "%s%3.3d", cfg->crlf, cfg->s[num]);
-      mdm_write_parity(cfg, tmp, strlen(tmp));
+      mdm_write(cfg, tmp, strlen(tmp));
       break;
     case 'T':  // defaut to tone dialing
       //cfg->default_dial_type=MDM_DT_TONE;
@@ -576,7 +574,7 @@ int mdm_handle_char(modem_config *cfg, char ch)
   if (cfg->cmd_started == TRUE) {
     if (ch == (char) (cfg->s[5])) {
       if (cfg->cur_line_idx == 0 && cfg->echo == TRUE) {
-        mdm_write_parity(cfg, "T", 1);
+        mdm_write(cfg, "T", 1);
       }
       else {
         cfg->cur_line_idx--;
@@ -631,6 +629,7 @@ int mdm_clear_break(modem_config *cfg)
 int mdm_parse_data(modem_config *cfg, char *data, int len)
 {
   int i;
+  int ch;
 
 
   if (cfg->cmd_mode == TRUE) {
@@ -642,7 +641,10 @@ int mdm_parse_data(modem_config *cfg, char *data, int len)
     line_write(cfg, data, len);
     if (cfg->pre_break_delay == TRUE) {
       for (i = 0; i < len; i++) {
-        if (data[i] == (char) cfg->s[2]) {
+	ch = data[i];
+	if (cfg->parity)
+	  ch &= 0x7f;
+        if (ch == (char) cfg->s[2]) {
           LOG(LOG_DEBUG, "Break character received");
           cfg->break_len++;
           if (cfg->break_len > 3) {     // more than 3, considered invalid