jcs
/subtext
/amendments
/240
telnet: Increase IAC SB buffer, log when it overflows
macOS telnet clients have a very long DISPLAY variable that was
reaching our limit of iac_sb, which then spilled into the login field
since we stop treating further data as IAC SB data.
jcs made amendment 240 about 1 year ago
--- telnet.c Sun Jul 31 23:00:59 2022
+++ telnet.c Thu Aug 11 09:17:23 2022
@@ -101,7 +101,7 @@ struct telnet_node {
unsigned short sending_iac;
unsigned short escaped_obuflen;
short iac_state;
- unsigned char iac_sb[64];
+ unsigned char iac_sb[128];
short sb_len;
/* docs say 4*MTU+1024, but MTU will probably be <1500 */
unsigned char tcp_buf[(4 * 1500) + 1024];
@@ -629,6 +629,7 @@ telnet_input(struct session *session)
/* IAC overflow */
node->iac_state = TELNET_IAC_STATE_IDLE;
node->sb_len = 0;
+ session_log(session, "IAC SB overflow");
}
}
break;