gonzo1948
March 31st, 2009, 02:33 PM
Hi,
I have 2 applications linked with the same libpcap library. The first
one is just a sanity app that makes a few calls to libpcap, including
pcap_lookupdevs(). The second app is a bit more extensive but also
calls pcap_lookupdevs() upon initialization.
If I run the 1st app with user myself, I get the typical message "no
suitable device found" from pcap_lookupdevs(). If I run the 1st app as
root, then it runs just fine, as expected.
When I run the 2nd app, pcap_lookupdevs() always fails with "no suitable
device found" regardless of whether I run the app as myself or as root.
I have traced the failure to the system call socket() in live_open_new()
(in the pcap-linux.c file). I print out both the user ID and the
effective user ID before and after the call to socket().
When I run the 1st app, the debugging printfs in live_open_new() print
out as expected. That is, when the 1st app is run as myself, both the
user ID and the effective user ID are me, and the call to socket() fails
with an "Operation not permitted" error.
When I run the 2nd app as root, the debugging printfs in live_open_new()
print out that the user ID is root (0) and the effective user ID is also
root (0), but the call to socket() still fails with the "Operation not
permitted" error.
Again, the same libpcap library is linked into both apps. I have tried
the most recent version of libpcap as well as several older
versions--all with the same results. I can run both apps from the same
root shell, yet the socket() call always fails in the 2nd app. I do not
think the problem is in this 2nd app, because, it runs fine on other
systems. It is just on my system that the socket() call fails in the 2nd
app.
I am running Ubuntu 8.04 and all my other network related apps that use
libpcap work just fine if I run them with sudo or as root. But in this
app, the pcap_lookupdevs() always fails EVEN WHEN RUN AS ROOT.
Any ideas on what could be causing socket() to fail (with Operation not
permitted) in the pcap routine live_open_new() even when running as root?
Thanks,
-Andres
I have 2 applications linked with the same libpcap library. The first
one is just a sanity app that makes a few calls to libpcap, including
pcap_lookupdevs(). The second app is a bit more extensive but also
calls pcap_lookupdevs() upon initialization.
If I run the 1st app with user myself, I get the typical message "no
suitable device found" from pcap_lookupdevs(). If I run the 1st app as
root, then it runs just fine, as expected.
When I run the 2nd app, pcap_lookupdevs() always fails with "no suitable
device found" regardless of whether I run the app as myself or as root.
I have traced the failure to the system call socket() in live_open_new()
(in the pcap-linux.c file). I print out both the user ID and the
effective user ID before and after the call to socket().
When I run the 1st app, the debugging printfs in live_open_new() print
out as expected. That is, when the 1st app is run as myself, both the
user ID and the effective user ID are me, and the call to socket() fails
with an "Operation not permitted" error.
When I run the 2nd app as root, the debugging printfs in live_open_new()
print out that the user ID is root (0) and the effective user ID is also
root (0), but the call to socket() still fails with the "Operation not
permitted" error.
Again, the same libpcap library is linked into both apps. I have tried
the most recent version of libpcap as well as several older
versions--all with the same results. I can run both apps from the same
root shell, yet the socket() call always fails in the 2nd app. I do not
think the problem is in this 2nd app, because, it runs fine on other
systems. It is just on my system that the socket() call fails in the 2nd
app.
I am running Ubuntu 8.04 and all my other network related apps that use
libpcap work just fine if I run them with sudo or as root. But in this
app, the pcap_lookupdevs() always fails EVEN WHEN RUN AS ROOT.
Any ideas on what could be causing socket() to fail (with Operation not
permitted) in the pcap routine live_open_new() even when running as root?
Thanks,
-Andres