Disabling ethernet leds on R8000 - "et robowr" equivalent?

Installing and Using OpenWrt
1

Hi all,

I'm trying to switch off the ethernet activiti LEDs on my new Netgear R8000. All other leds can be controlled via GPIO but not those ones.

I found this procedure for DD-WRT, which uses the et robowr tool.

Does anyone know how to achieve this on openWRT? Googling "et openwrt" was not really successful...

Edit:
This "et" utility is in the stock firmware (thanks binwalk) in /usr/sbin:

$ file usr/sbin/et 
usr/sbin/et: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-uClibc.so.0, stripped

I boldly extracted it from the firmware and scp'd it to my box, but no way to execute it (this was to be expected):

root@OpenWrt:~# ll
-rwxr-xr-x    1 root     root       11.1K Apr 28 15:41 et
root@OpenWrt:~# ./et 
-ash: ./et: not found

Any idea? maybe compile it by hand? Does anybody know where to find the sources?

Cheers,
NicolaF

2

Replying to myself. This was a libc issue. Extracting ld-uClibc.so and libc.so from the stock firmware helped, but there's still somthing wrong:

root@OpenWrt:~# l
et         libc.so.0
root@OpenWrt:~# LD_LIBRARY_PATH=/root/  ./et -a eth0 robowr 0x0 0x18 0x0 
etcrobowr: Operation not supported
root@OpenWrt:~# echo $?
1

Any idea ?

3

Update: I straced et to dive deeper:

root@OpenWrt:/# strace -s 100 -E LD_LIBRARY_PATH=/root /root/et -i eth0 robowr 0x0 0x18 0x1ff
execve("/root/et", ["/root/et", "-i", "eth0", "robowr", "0x0", "0x18", "0x1ff"], 0xb7550 /* 15 vars */) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|1<<MAP_HUGE_SHIFT, -1, 0) = 0xb6fb3000
open("/root/libc.so.0", O_RDONLY)       = 3
fstat(3, {st_mode=S_IFREG|0755, st_size=420536, ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|1<<MAP_HUGE_SHIFT, -1, 0) = 0xb6fb2000
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0(\0\1\0\0\0\220I\1\0004\0\0\0\250f\6\0\2\0\0\0054\0 \0\10\0(\0\32\0\31\0\1\0\0p\210N\6\0\210N\6\0\210N\6\08\0\0\08\0\0\0\4\0\0\0\4\0\0\0\6\0\0\0004\0\0\0004\0\0\0004\0\0\0"..., 4096) = 4096
mmap2(NULL, 475136, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb6f34000
mmap2(0xb6f34000, 413376, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED, 3, 0) = 0xb6f34000
mmap2(0xb6fa1000, 4980, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3, 0x65000) = 0xb6fa1000
mmap2(0xb6fa3000, 17872, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xb6fa3000
close(3)                                = 0
munmap(0xb6fb2000, 4096)                = 0
stat("/lib/ld-uClibc.so.0", {st_mode=S_IFREG|0755, st_size=21256, ...}) = 0
open("/dev/urandom", O_RDONLY)          = 3
read(3, "N\f \252", 4)                  = 4
close(3)                                = 0
mprotect(0xb6fa1000, 4096, PROT_READ)   = 0
mprotect(0xb6fb4000, 4096, PROT_READ)   = 0
ioctl(0, TCGETS, {B38400 opost isig icanon echo ...}) = 0
ioctl(1, TCGETS, {B38400 opost isig icanon echo ...}) = 0
socket(AF_INET, SOCK_DGRAM, IPPROTO_IP) = 3
ioctl(3, _IOC(_IOC_NONE, 0x89, 0xff, 0), 0xbe8d5c20) = -1 EOPNOTSUPP (Not supported)
write(2, "etcrobowr", 9etcrobowr)                = 9
write(2, ": ", 2: )                       = 2
write(2, "Operation not supported", 23Operation not supported) = 23
write(2, "\n", 1
)                       = 1
exit(1)                                 = ?
+++ exited with 1 +++

So the culprit is the ioctl syscall. Looking at Netgear's open source code from here, we can see that

  • the et binary is prebuilt
  • the et kernel module is prebuilt too
  • there is some interesting stuff in src/shared/bcmrobo.c, which is apparently broadcom's switch driver
4

Maybe this will add some light to your figuring (:smile:) but I found that, by default, with generic LED rules deleted, the USB 2 light is always on. I couldn't get it to go off with any USB 2 light rules but I was able to get the USB 2 light to go off by setting the USB 3 light as always off by default.
Strange behavior but an easy fix.