Date: Wed, 4 Dec 2002 21:36:09 +0100 From: Marc Olzheim <marcolz@stack.nl>, Jan Willem Knopper <jwk@stack.nl>, Dean Strik <dean@stack.nl> To: FreeBSD-gnats-submit@FreeBSD.org Cc: Marc Olzheim <marcolz@stack.nl>, Jan Willem Knopper <jwk@stack.nl>, Dean Strik <dean@stack.nl> Subject: bin/45995: Telnet fails to properly handle SIGPIPE on its terminal. Message-ID: <20021204203609.GA26229@stack.nl>
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>Number: 45995 >Category: bin >Synopsis: Telnet fails to properly handle SIGPIPE on its terminal. >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Dec 04 12:40:03 PST 2002 >Closed-Date: >Last-Modified: >Originator: Marc Olzheim, Jan Willem Knopper, Dean Strik >Release: FreeBSD 2.x-5.x >Organization: M.C.G.V. Stack >Environment: System: FreeBSD toad.stack.nl 4.7-STABLE FreeBSD 4.7-STABLE #0: Wed Nov 13 20:17:40 CET 2002 marcolz@vwww.stack.nl:/vwww.mnt/triceratops/sources/4.x/sys/compile/toad_vwww i386 >Description: When telnet's terminal-output is a pipe and when that pipe is closed, before telnet has flushed it's buffer, it will endlessly keep trying to flush it anyway, resulting in an 100% cpu eating telnet. >How-To-Repeat: telnet to a port giving more than one line of output and pipe it through grep -q on something that occurs in thar output. For example: telnet mud.stack.nl 3333 | grep -q a8888b >Fix: Patch attached: --WIyZ46R2i8wDzkSu Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="telnet.patch" --- /usr/src/usr.bin/telnet/externs.h Wed Dec 4 21:06:27 2002 +++ /usr/src/usr.bin/telnet/externs.h Wed Dec 4 21:14:14 2002 @@ -263,6 +263,7 @@ tel_leave_binary(int), TerminalFlushOutput(void), TerminalNewMode(int), + TerminalPanic(void), TerminalRestoreState(void), TerminalSaveState(void), TerminalDefaultChars(void), --- /usr/src/usr.bin/telnet/sys_bsd.c Wed Dec 4 21:01:44 2002 +++ /usr/src/usr.bin/telnet/sys_bsd.c Wed Dec 4 21:13:56 2002 @@ -131,6 +131,12 @@ errno = 0; } +void +TerminalPanic() +{ + (void) intr2(0); +} + int TerminalWrite(char *buf, int n) { --- /usr/src/usr.bin/telnet/terminal.c Wed Dec 4 20:57:34 2002 +++ /usr/src/usr.bin/telnet/terminal.c Wed Dec 4 21:16:16 2002 @@ -148,7 +148,13 @@ ring_consumed(&ttyoring, n); } if (n < 0) + { + /* If flushing the terminal is no longer possible, panic ! + */ + if (EPIPE == errno) + TerminalPanic(); return -1; + } if (n == n0) { if (n0) return -1; --WIyZ46R2i8wDzkSu-- >Release-Note: >Audit-Trail: >Unformatted: --WIyZ46R2i8wDzkSu Content-Type: text/plain; charset=us-ascii Content-Disposition: inline To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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