Package: libc6 Version: 2.3.2.ds1-11 Severity: normal Hello:
I was playing around with a Debian Sid box with kernel 2.6.4, ipsec-tools 0.2.2-8, libc 2.3.2.ds1-11 and racoon 0.2.2-8 to make some tests and suddenly I realized racoon was unable to start. I have other box around here with the exact same kernel, libc6, racoon and ipsec-tools version, and "racoon" starts normally. Different hardware, but same software installed on both. I started "racoon" in the foreground and was given a "SIGSEGV" error message. Then I recompiled the Debian package to include debugging information and uses "ddd" to debug the problem. After some time I found the point where it fails, exactly at line 345 from src/racoon/grabmyaddr.c: if (ifap->ifa_addr->sa_family != AF_INET Using the pretty "display" option in "ddd" I peeked inside the "ifap" ifaddrs structure, and realized that is a NULL pointer. So the second indirection fails with the SIGSEGV error message. The preceeding "for" loop iterates over a linked list of detected local network interfaces, which was previously created by getifaddrs() libc function issued at line 334 at the same source file. In my local setup this linked list consists of structures for (and in this order) "lo", "eth0", "sit0", "ppp0" and "dummy0" (and this last one links back to the first in the list). Well, it seems the _only_ node with a "ifa_addr" member not initialized is that of "ppp0", that is a NULL pointer instead of one to a "sockaddr" structure. The interface "dummy0" was added in a second test, just to see if being the last node in the list had something to do with the problem, but it doesn't seem so. That is the only reason why "racoon" worked at one box, but not at the other: the box where it fails has a PPP connection to the Internet and the other doesn't. When the PPP interface is down, for example, at boot time, the ppp0 interface doesn't exist, getifaddrs() gets all the other interfaces, populates the structures correctly, and "racoon" starts ok. So it seems there is some kind of problem with getifaddrs() in Debian Sid libc6 2.3.2.ds1-11, or maybe in the Linux kernel, or some strange interaction between the two. I am going to try with some other kernel versions just in case, and if you need it I can upload a couple of screenshots that show the linked list of interfaces both with ppp0 up and without. Hope it helps. Keep up the good work ! -- Jos� Luis Domingo L�pez Linux Registered User #189436 Debian Linux Sid (Linux 2.6.4)
