telnet: convert CR -> CR LF, not CR -> CR NUL when sending data to server

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/networking/telnet.c b/networking/telnet.c
index e8e51dce4aaa7cc314155cf0bf2fd5eaa71731c5..7081a6a41ba95e1f2191a73e3ccd92fe6f2f4a38 100644 (file)
--- a/networking/telnet.c
+++ b/networking/telnet.c
@@ -186,22 +186,6 @@ static void con_escape(void)
 
 static void handle_net_output(int len)
 {
-       /* here we could do smart tricks how to handle 0xFF:s in output
-        * stream like writing twice every sequence of FF:s (thus doing
-        * many write()s. But I think interactive telnet application does
-        * not need to be 100% 8-bit clean, so changing every 0xff:s to
-        * 0x7f:s
-        *
-        * 2002-mar-21, Przemyslaw Czerpak (druzus@polbox.com)
-        * I don't agree.
-        * first - I cannot use programs like sz/rz
-        * second - the 0x0D is sent as one character and if the next
-        *      char is 0x0A then it's eaten by a server side.
-        * third - why do you have to make 'many write()s'?
-        *      I don't understand.
-        * So I implemented it. It's really useful for me. I hope that
-        * other people will find it interesting too.
-        */
        byte outbuf[2 * DATABUFSIZE];
        byte *p = (byte*)G.buf;
        int j = 0;
@@ -216,7 +200,11 @@ static void handle_net_output(int len)
                if (c == IAC)
                        outbuf[j++] = c; /* IAC -> IAC IAC */
                else if (c == '\r')
-                       outbuf[j++] = '\0'; /* CR -> CR NUL */
+                       /* See RFC 1123 3.3.1 Telnet End-of-Line Convention.
+                        * Using CR LF instead of other allowed possibilities
+                        * like CR NUL - easier to talk to HTTP/SMTP servers.
+                        */
+                       outbuf[j++] = '\n'; /* CR -> CR LF */
        }
        if (j > 0)
                full_write(netfd, outbuf, j);

diff --git a/networking/telnetd.c b/networking/telnetd.c
index 33020f1b416436d6ad1315459704637401ca4a40..9e7a84cce200c2bfa2cf62d1493bed60cf1d2732 100644 (file)
--- a/networking/telnetd.c
+++ b/networking/telnetd.c
@@ -125,6 +125,7 @@ remove_iacs(struct tsession *ts, int *pnum_totty)
                        /* We map \r\n ==> \r for pragmatic reasons.
                         * Many client implementations send \r\n when
                         * the user hits the CarriageReturn key.
+                        * See RFC 1123 3.3.1 Telnet End-of-Line Convention.
                         */
                        if (c == '\r' && ptr < end && (*ptr == '\n' || *ptr == '\0'))
                                ptr++;