Finless 1.6 and tcpdump

[n0n0x]

Hello guys,

I've searched for this, but couldn't find anything related to it, so I am opening a new thread.


I've been trying to use tcpdump with the finless 1.6 mod on my mk808, but every time I run it, I get the following:

/mnt/sdcard # tcpdump -i wlan0
tcpdump: socket: Operation not permitted
/mnt/sdcard # su - 

1|root@android:/mnt/sdcard # tcpdump -s 65535 -i wlan0 -w dump.pcap                                                  
tcpdump: socket: Operation not permitted
1|root@android:/mnt/sdcard # tcpdump -s 65535 -i wlan0                                                               
tcpdump: socket: Operation not permitted
1|root@android:/mnt/sdcard # tcpdump -i wlan0                                                                        
tcpdump: socket: Operation not permitted
1|root@android:/mnt/sdcard # tcpdump                                                                                 
tcpdump: socket: Permission denied

Any ideas?

Cheers!

[n0n0x]

Hello guys,

I've searched for this, but couldn't find anything related to it, so I am opening a new thread.


I've been trying to use tcpdump with the finless 1.6 mod on my mk808, but every time I run it, I get the following:

/mnt/sdcard # tcpdump -i wlan0
tcpdump: socket: Operation not permitted
/mnt/sdcard # su - 

1|root@android:/mnt/sdcard # tcpdump -s 65535 -i wlan0 -w dump.pcap                                                  
tcpdump: socket: Operation not permitted
1|root@android:/mnt/sdcard # tcpdump -s 65535 -i wlan0                                                               
tcpdump: socket: Operation not permitted
1|root@android:/mnt/sdcard # tcpdump -i wlan0                                                                        
tcpdump: socket: Operation not permitted
1|root@android:/mnt/sdcard # tcpdump                                                                                 
tcpdump: socket: Permission denied

Any ideas?

Cheers!

Solved! The default user:group for the tcpdump binary in finless is system:system

# ls -lh /system/xbin/tcpdump
-rwsrwsrwx    1 system   system    637.6K Oct 27 00:37 /system/xbin/tcpdump

what I did was to change them to root:root

cd /system/xbin
/system/xbin # mount
...
/dev/block/mtdblock8 on /system type ext4 (ro,noatime,nodiratime,barrier=1,data=ordered,noauto_da_alloc)
...
/system/xbin # mount -o remount,rw,noatime,nodiratime,barrier=1,data=ordered,noauto_da_alloc /dev/block/mtdblock8 /system
/system/xbin # mount
...
/dev/block/mtdblock8 on /system type ext4 (rw,noatime,nodiratime,barrier=1,data=ordered,noauto_da_alloc)
...
/system/xbin # chown -R root: tcpdump
/system/xbin # mount -o remount,ro,noatime,nodiratime,barrier=1,data=ordered,noauto_da_alloc /dev/block/mtdblock8 /system
/system/xbin # mount
...
/dev/block/mtdblock8 on /system type ext4 (ro,noatime,nodiratime,barrier=1,data=ordered,noauto_da_alloc)
...
/system/xbin # cd /mnt/sdcard
/mnt/sdcard # tcpdump -i wlan0 -s 65535 -w testdump.pcap
tcpdump: listening on wlan0, link-type EN10MB (Ethernet), capture size 65535 bytes
^C3115 packets captured
3115 packets received by filter
0 packets dropped by kernel
/mnt/sdcard # ls -lh testdump.pcap 
-rwxrwxr-x    1 system   sdcard_r    2.1M Feb 24 23:34 testdump.pcap
/mnt/sdcard #

now I can debug network apps in peace

Finless, is there any chance you can implement this change in your upcoming firmwares? (Not saying right away for the 1.7, but would be great to keep it in mind) Don't know if you have some kind of bugtracker or features request where I could post this. Just let me know if you have one

Cheers!