--- lbbs/src/bbs_net.c	2025/10/18 01:50:48	1.66
+++ lbbs/src/bbs_net.c	2025/10/20 04:17:36	1.73
@@ -47,8 +47,6 @@
 #define MAXSTATION 26 * 2
 #define STATION_PER_LINE 4
 
-#define BBS_NET_DEFAULT_CHARSET "UTF-8"
-
 struct _bbsnet_conf
 {
 	char host1[20];
@@ -209,14 +207,15 @@ int bbsnet_connect(int n)
 	int output_buf_len = 0;
 	int input_buf_offset = 0;
 	int output_buf_offset = 0;
-	iconv_t input_cd = NULL;
 	char input_conv[LINE_BUFFER_LEN * 2];
 	char output_conv[LINE_BUFFER_LEN * 2];
 	int input_conv_len = 0;
 	int output_conv_len = 0;
 	int input_conv_offset = 0;
 	int output_conv_offset = 0;
+	iconv_t input_cd = NULL;
 	iconv_t output_cd = NULL;
+	char tocode[32];
 	struct epoll_event ev, events[MAX_EVENTS];
 	int nfds, epollfd;
 	int stdin_read_wait = 0;
@@ -425,16 +424,21 @@ int bbsnet_connect(int n)
 	log_common("BBSNET connect to %s:%d from %s:%d by [%s]\n",
 			   remote_addr, remote_port, local_addr, local_port, BBS_username);
 
-	input_cd = iconv_open(bbsnet_conf[n].charset, BBS_NET_DEFAULT_CHARSET);
+	snprintf(tocode, sizeof(tocode), "%s%s", bbsnet_conf[n].charset,
+			 (strcasecmp(stdio_charset, bbsnet_conf[n].charset) == 0 ? "" : "//IGNORE"));
+	input_cd = iconv_open(tocode, stdio_charset);
 	if (input_cd == (iconv_t)(-1))
 	{
-		log_error("iconv_open(%s->%s) error: %d\n", BBS_NET_DEFAULT_CHARSET, bbsnet_conf[n].charset, errno);
+		log_error("iconv_open(%s->%s) error: %d\n", stdio_charset, tocode, errno);
 		goto cleanup;
 	}
-	output_cd = iconv_open(BBS_NET_DEFAULT_CHARSET, bbsnet_conf[n].charset);
-	if (input_cd == (iconv_t)(-1))
+
+	snprintf(tocode, sizeof(tocode), "%s%s", stdio_charset,
+			 (strcasecmp(bbsnet_conf[n].charset, stdio_charset) == 0 ? "" : "//TRANSLIT"));
+	output_cd = iconv_open(tocode, bbsnet_conf[n].charset);
+	if (output_cd == (iconv_t)(-1))
 	{
-		log_error("iconv_open(%s->%s) error: %d\n", bbsnet_conf[n].charset, BBS_NET_DEFAULT_CHARSET, errno);
+		log_error("iconv_open(%s->%s) error: %d\n", bbsnet_conf[n].charset, tocode, errno);
 		iconv_close(input_cd);
 		goto cleanup;
 	}
@@ -532,6 +536,11 @@ int bbsnet_connect(int n)
 					}
 					else if (ret == 0)
 					{
+						// Send NO-OP to remote server
+						input_buf[input_buf_len] = '\0';
+						input_buf_len++;
+						BBS_last_access_tm = time(NULL);
+
 						stdin_read_wait = 0;
 						break; // Check whether channel is still open
 					}
@@ -587,11 +596,28 @@ int bbsnet_connect(int n)
 		{
 			if (input_buf_offset < input_buf_len)
 			{
+				// For debug
+#ifdef _DEBUG
+				for (int j = input_buf_offset; j < input_buf_len; j++)
+				{
+					log_error("Debug input: <--[%u]\n", (input_buf[j] + 256) % 256);
+				}
+#endif
+
 				ret = io_buf_conv(input_cd, input_buf, &input_buf_len, &input_buf_offset, input_conv, sizeof(input_conv), &input_conv_len);
 				if (ret < 0)
 				{
 					log_error("io_buf_conv(input, %d, %d, %d) error\n", input_buf_len, input_buf_offset, input_conv_len);
+					input_buf_len = input_buf_offset; // Discard invalid sequence
+				}
+
+				// For debug
+#ifdef _DEBUG
+				for (int j = input_conv_offset; j < input_conv_len; j++)
+				{
+					log_error("Debug input_conv: <--[%u]\n", (input_conv[j] + 256) % 256);
 				}
+#endif
 			}
 
 			while (input_conv_offset < input_conv_len && !SYS_server_exit)
@@ -686,6 +712,7 @@ int bbsnet_connect(int n)
 				if (ret < 0)
 				{
 					log_error("io_buf_conv(output, %d, %d, %d) error\n", output_buf_len, output_buf_offset, output_conv_len);
+					output_buf_len = output_buf_offset; // Discard invalid sequence
 				}
 			}
 
@@ -775,6 +802,8 @@ cleanup:
 			   tm_used->tm_mday - 1, tm_used->tm_hour, tm_used->tm_min,
 			   tm_used->tm_sec);
 
+	BBS_last_access_tm = time(NULL);
+
 	return 0;
 }
 
@@ -843,10 +872,10 @@ int bbs_net()
 	{
 		ch = igetch(100);
 
-        if (ch != KEY_NULL && ch != KEY_TIMEOUT)
-        {
-            BBS_last_access_tm = time(NULL);
-        }
+		if (ch != KEY_NULL && ch != KEY_TIMEOUT)
+		{
+			BBS_last_access_tm = time(NULL);
+		}
 
 		switch (ch)
 		{