Date: Fri, 19 Mar 2004 21:29:40 -0800 (PST) From: Pavlin Radoslavov <pavlin@icir.org> To: freebsd-gnats-submit@FreeBSD.org Subject: java/64492: NetworkInterface.getNetworkInterfaces() leaks file descriptors Message-ID: <200403200529.i2K5TeSr099312@www.freebsd.org> Resent-Message-ID: <200403200530.i2K5UNsK097273@freefall.freebsd.org>
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>Number: 64492
>Category: java
>Synopsis: NetworkInterface.getNetworkInterfaces() leaks file descriptors
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: freebsd-java
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Fri Mar 19 21:30:22 PST 2004
>Closed-Date:
>Last-Modified:
>Originator: Pavlin Radoslavov
>Release: 4.8-RELEASE
>Organization:
ICSI
>Environment:
FreeBSD xorp8.icir.org 4.8-RELEASE FreeBSD 4.8-RELEASE #0: Wed May 28 11:19:23 PDT 2003 root@xorp8.icir.org:/usr/src/sys/compile/XORP8-4.8 i386
>Description:
Every time NetworkInterface.getNetworkInterfaces() is called
on a system with IPv6 enabled it leaks a file descriptor (UDP socket).
This is on a system with lastest port collection with
jdk14 and with the lastest jdk14 patches
(bsd-jdk14-patches-6.tar.gz)
>How-To-Repeat:
Write a simple program that repeatedly calls
NetworkInterface.getNetworkInterfaces()
Run the program and then in parallel list the number of
open UDP socket. E.g.:
lsof | egrep java | egrep UDP
The output should be a growing list of opened UDP sockets
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
..
java 35251 pavlin 8u IPv4 0xddf80a00 0t0 UDP *:*
java 35251 pavlin 9u IPv4 0xddf80ac0 0t0 UDP *:*
java 35251 pavlin 10u IPv4 0xddf80b80 0t0 UDP *:*
java 35251 pavlin 11u IPv4 0xddf80c40 0t0 UDP *:*
java 35251 pavlin 12u IPv4 0xddf80d00 0t0 UDP *:*
java 35251 pavlin 13u IPv4 0xddf80dc0 0t0 UDP *:*
..
>Fix:
The problem can be traced down to the BSD-specific patch applied
by bsd-jdk14-patches-6.tar.gz
More specifically, in the BSD iplementation of
enumIPv4Interfaces() inside
/usr/ports/java/jdk14/work/j2se/src/solaris/native/java/net/NetworkInterface.c
Every time this function is called it leaks a file descriptor
if IPv6 is enabled: first an IPv4 SOCK_DGRAM socket is opened,
but then variable "sock" is reasigned to an IPv6 socket without
closing the IPv4 socket. The simple patch below fixes the problem:
--- work/j2se/src/solaris/native/java/net/NetworkInterface.c.leak Wed Feb 25 14:19:21 2004
+++ work/j2se/src/solaris/native/java/net/NetworkInterface.c Fri Mar 19 20:17:33 2004
@@ -605,6 +605,7 @@
/*
* Do this check early to avoid unnecessary work.
*/
+ close(sock); /* XXX: close the IPv4 socket */
if (ipv6_available()) {
sock = JVM_Socket(AF_INET6, SOCK_DGRAM, 0);
if (sock < 0) {
A better solution is to close "sock" soon after every time
it is opened because it is not used for anything more than
to verify that an IPv4/IPv6 socket can be opened.
>Release-Note:
>Audit-Trail:
>Unformatted:
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