Capabilities & Linux & Java
- by Marek Jelen
Hi, I am experimenting with linux capabilities for java application ... I do not want to add capabilities to interpreter (JVM), so I tried to write simple wrapper (with debugging information printed to stdout):
#include <stdio.h>
#include <stdlib.h>
#include <sys/capability.h>
#include <unistd.h>
int main(int argc, char *argv[]){
cap_t cap = cap_get_proc();
if (!cap) {
perror("cap_get_proc");
exit(1);
}
printf("%s: running with caps %s\n", argv[0], cap_to_text(cap, NULL));
return execlp("/usr/bin/java", "-server", "-jar", "project.jar", (char *)NULL);
}
This way, I can se that the capability is set for this execucatable:
./runner: running with caps = cap_net_bind_service+p
And getcap shows
runner = cap_net_bind_service+ip
I have the capability set to be inheritable, so there should be no problem. However java still don't want to bind to privileged ports :-(
I am getting this error:
sun/nio/ch/Net.java:-2:in `bind': java.net.SocketException: Permission denied (NativeException)
Can someone help me to resolve this?
Thanks in advance
