[sctp-dev] Undefined symbol problems in libsctp.so running with java 1.6

[Jason Kania]

Thanks very much!

You were correct with both messages. For others that may hit this issue, I thought I would respond to the group. The problem that produced the error was:

1) the lksctp-tools package was not on the server (I didn't know it was required)
2) the lksctp-tools package contains a libsctp.so library that the the openJDK SCTP libsctp.so library is seeking
3) the LD_LIBRARY_PATH on the server included the path to the libsctp.so from the openJDK sctp implementation

The result was the odd library loader message that seemed to indicate that the library could not find symbols within itself.

Jason

-----Original Message-----
From: Chris Hegarty
To: Jason 
Cc: sctp-dev at openjdk.java.net
Subject: Re: [sctp-dev] Undefined symbol problems in libsctp.so running with java 1.6

OH OH OH Stop. I just noticed this after clicking send.

The JDK JNI libsctp.so library needs to load /usr/lib/libsctp.so, to locate some extension functions. It would appear that JDK JNI libsctp.so is finding itself rather than /usr/lib/libsctp.so.

There must be an issue with your LD_LIBRARY_PATH. Can you check this?

-Chris.

On 10/ 7/11 06:43 PM, Chris Hegarty wrote:
> Jason,
>
> This exception would appear to indicate a problem trying to locate 
> sctp_getladdrs in the lksctp socket exceptions library, 
> /usr/lib/libsctp.so. Yes poor naming, I know. The lksctp socket 
> exceptions library has the same name as the internal JDK JNI library!
>
> Can you try looking at the output of:
> nm /usr/lib/libsctp.so
> objdump -T /usr/lib/libsctp.so
>
> -Chris.
>
>
> On 10/ 7/11 04:36 PM, Jason Kania wrote:
>> Hello,
>>
>> For RHEL 5 linux with kernel 2.6.18-92.1.22.el5, I downloaded the 
>> latest JDK 7 source and libsctp.so library. I am attempting to use 
>> the code modified for java 1.6, but I am encountering the following problem:
>>
>> > java -Xbootclasspath/a:sctp6.jar -classpath app.jar TestSCTP
>>
>> Exception in thread "main" java.lang.UnsupportedOperationException:
>> /usr/java/jre1.6.0_12/lib/i386/libsctp.so: undefined symbol:
>> sctp_getladdrs
>>
>> at sun.nio.ch.SctpNet.socket0(Native Method)
>>
>> at sun.nio.ch.SctpNet.socket(SctpNet.java:82)
>>
>> at sun.nio.ch.SctpChannelImpl.<init>(SctpChannelImpl.java:131)
>>
>> at com.sun.nio.sctp.SctpChannel.open(SctpChannel.java:165)
>>
>> at TestSCTP.main(TestSCTP.java:4)
>>
>> app.jar is simply a jar to hold the TestSCTP.class file.
>>
>> The problem is the same when I use the libsctp.so file from the SCTP 
>> on
>> 1.6 instruction page
>>
>> http://openjdk.java.net/projects/sctp/html/sctp6.html
>>
>> From the error output, the library is definitely being found.
>>
>> When I use the nm command to list what symbols are in the library, I 
>> get the following name with "nio_" prefix instead:
>>
>> > nm /usr/java/jre1.6.0_12/lib/i386/libsctp.so
>>
>> ...
>>
>> nio_sctp_getladdrs
>>
>> ...
>>
>> The ldd output looks as follows:
>>
>> > ldd /usr/java/jre1.6.0_12/lib/i386/libsctp.so
>>
>> linux-gate.so.1 => (0xffffe000)
>>
>> libnio.so => /usr/java/jre1.6.0_12/lib/i386/libnio.so (0xf7f58000)
>>
>> libnet.so => /usr/java/jre1.6.0_12/lib/i386/libnet.so (0xf7f44000)
>>
>> libpthread.so.0 => /lib/libpthread.so.0 (0xf7f27000)
>>
>> libdl.so.2 => /lib/libdl.so.2 (0xf7f23000)
>>
>> libjava.so => /usr/java/jre1.6.0_12/lib/i386/libjava.so (0xf7efd000)
>>
>> libjvm.so => not found
>>
>> libc.so.6 => /lib/libc.so.6 (0xf7dba000)
>>
>> libnsl.so.1 => /lib/libnsl.so.1 (0xf7da3000)
>>
>> /lib/ld-linux.so.2 (0xf7f66000)
>>
>> libjvm.so => not found
>>
>> libjvm.so => not found
>>
>> libverify.so => /usr/java/jre1.6.0_12/lib/i386/libverify.so 
>> (0xf7d96000)
>>
>> libjvm.so => not found
>>
>> Permissions on the file and directories are all 755
>>
>> The libsctp.jar library is included on the JVM command line as follows:
>>
>> Any suggestions on a direction for resolving this?
>>
>>
>> Thanks for any help,
>>
>> Jason
>>