I have a target board where there is a can interface driven by peak drivers. On the host side I installed can-utils. I have a can cable which gets detected as /dev/ttyUSBx when I plugin.
The target board receives candata at 500000 baud rate
So on the host I executed,
sudo modprobe can
sudo modprobe can-raw
sudo modprobe slcan
sudo slcand -o -s8 -t hw -S 500000 /dev/ttyUSBx
sudo ip link set up slcan0
then I sent the candata from the host using:
cansend slcan0 600#ffffffffffffff
I can see the same using candump slcan0 on the host.
But I don't receive anything on the target.
I tried the same with other cable in which I used (on the host)
sudo modprobe can
sudo ip link set can0 type can bitrate 500000 triple-sampling on
sudo ifconfig can0 up
then I was able to send can messages. If I try the same on the previous cable it throws error saying Cannot find device "can0".
So How do I send through slcan interface?
Your CAN bitrate is wrong. To setup 500kbit/s you need to invoke following commands:
sudo slcand -o -s6 -t hw -S 3000000 /dev/ttyUSBx
sudo ip link set up slcan0
-s6 means CAN bitrate 500kbit/s, -s8 means 1Mbit/s. -S parameter is used to setup serial speed to the USB-to-serial controller in the USB-to-CAN cable. The full CAN bitrate table for slcan can be found here.
source
ASCII Command, CAN Bitrate
s0 10 Kbit/s
s1 20 Kbit/s
s2 50 Kbit/s
s3 100 Kbit/s
s4 125 Kbit/s
s5 250 Kbit/s
s6 500 Kbit/s
s7 800 Kbit/s
s8 1000 Kbit/s
Related
My internet over usb used to just work on my BBB but now every time I boot I have to manually add
route add default gw 192.168.7.1
echo "nameserver 8.8.8.8" >> /etc/resolv.conf
I as following this guide but in /opt/scripts/boot/am335x_evm.sh
I can no longer find
/sbin/ifconfig usb0 192.168.7.2 netmask 255.255.255.252
/usr/sbin/udhcpd -S /etc/udhcpd.conf`
so I can add /sbin/route add default gw 192.168.7.1 metric 1
Where can I add this line?
edit: Host computer is windows 10.
The kernel maintainers update the kernel for that chip-family daily, so you should git pull that /opt directory you mentioned and then run the ./kernel_update in /opt/path/to/tools.
All of the directories on the BBB that can be updated in this manner are on https://github.com/RobertCNelson.
ps. I also updated my device tree files.
I'm using iperf3 that is supposedly a rewritten version of iperf. Reason why Im using this is because I love iperf when it comes to TCP and UDP throughput and I now want to test SCTP throughput between my end-points.
However when I'm trying to use the --sctp command that I've seen people been using it says command not recognizable. Is it the implementation I'm using that have not implemented this command?
https://github.com/esnet/iperf
This is the implementation I'm using, can't find any obvious documentation of the SCTP commands related to this. Most SCTP iperf implementations are added manually in the tests and the source code is often not provided.
Any help would be appreciated!
Get a copy of iperf which supports lksctp module of linux kernel. Install it using the standard process. (If it fails, please inform with the error message and the operating system and kernel details). Now to use SCTP in iperf these are the proper syntaxes.
For creating an SCTP server,
iperf -z -s
(-z is for selecting the SCTP protocol and -s is for server.)
For creating an SCTP client,
iperf -z -c <host address> -t <time duration for the connection in second>s -i <interval of the time to print the bandwidth in terminal in second>s
(-z for SCTP, -c is for client. Host address should be the ip address of the server where iperf -z -s is already running. -t is to specify the communication time duration. -i is to specify the interval to show the bandwidth.)
Example:
iperf -z -c 0.0.0.0 -t 10s -i 2s
Here the communication time is 10 seconds and it'll report the bandwidth for each 2 seconds interval.
P.S.
(1) To use iperf for SCTP, you must enable the SCTP module in the kernel and recompile it. The kernel version must be 2.6 or above. Check it using uname -a or uname -r. If you have a lower one, then download a new kernel from The Linux Kernel Archives. And compile it by enabling SCTP.
First check if it is already enabled or not by running these two commands in the terminal.
modprobe sctp
lsmod | grep sctp If you get any output then SCTP is already enabled.
(2) If still iperf with -z fails. Try the following solution. If the two machines are 'A' and 'B'.
First make 'A' the server and 'B' the client. It won't succeed. So
exit by using `ctrl + z` and kill iperf
using `pkill -9 iperf`.
Then make 'B' the server and 'A' the client. It may succeed. If it fails again, kill iperf using the above command and repeat step 1 again. it might get succeeded.
(The 2nd solution works for me with fedora 20 and kernel 2.6 and above.)
Couldn't find any recent answers through googling so I though I would leave an answer here for those looking to installing Iperf3 to use SCTP on RHEL / CentOS.
You'll need to install lksctp-tools-devel first and build from source to enable the SCTP support. Yum Install Iperf3 3.17 with lksctp-tools-devel did not enable SCTP for me.
Currently I am transporting files back and forth over telnet and I would like to send multiple files at once.
However, my target platform (a Blackfin processor) does not have "tar" enabled in its kernel/busybox configuration (a uClinux distribution).
As you all know the normal command is:
nc -p 12345 -l | tar -x
tar -c * | nc 192.168.0.100 12345 # with x.100 the robot IP address
How can I send multiple files using netcat without using tar?
Please, consider that I cannot easily add binaries on the platform. It would be best to do it with basic utilities and/or shell scripts.
Finally managed myself to do this, it can be done!
Here $l> stands for your machine with IP 192.168.0.10. And $e> is done on the embedded device without tar, in my case a robot. It uses old-fashioned dd which is able to copy an entire disk.
$l> nc -p 12345 -l | dd obs=4K of=/tmp/file.jffs2
$e> dd ibs=4K if=/dev/mtdblock2 | nc 192.168.0.10 12345
This is it, but because not everybody knows how to read a filesystem that is in this form, this is how you mount it:
file /tmp/file.jffs2
/tmp/file.jffs2: Linux jffs2 filesystem data little endian
sudo su #careful
mknod /tmp/mtdblock0 b 31 0
modprobe loop
losetup /dev/loop0 /tmp/file.jffs2
modprobe mtdblock
modprobe block2mtd
echo "/dev/loop0,128KiB" > /sys/module/block2mtd/parameters/block2mtd
modprobe jffs2
mkdir /media/robot
mount -t jffs2 /tmp/mtdblock0 /media/robot
Ctrl-D #back as normal user
And yes, you need the loopback device, or else:
sudo mount -t jffs2 /tmp/file.jffs2 /media/robot
mount: /tmp/file.jffs2 is not a block device (maybe try `-o loop'?)
Logically, it is a file (chars), and not a block device. The only thing I do not know is if there is a syntax for dd in which the command on the embedded device, can only select a subset of the filesystem to be included. I don't think this is likely because that would require dd to understand jffs2 while its strength is its raw byte copying behaviour.
When capturing H460 data on wireshark (on multiplexed mode), wireshark does not parse RTP data correctly. it should discard first 4 bytes on any RTP packet. looking for hints how to do that
Thanks
Amit
shark (packaged with wireshark) has this functionality built in.
Make sure that wireshark/tshark is in your PATH variable, and open a new command line window if you've just set it. Let me know if you want me to be more clear there.
If you want to discard the first 4 packets of rtp data on the fly :
tcpdump -i eth0 port ! 5060 and dst 192.168.1.101 -T rtp -n -s0 -w- | editcap -F libpcap -C 4 - - | tcpdump -nlvvv -r - -w output.pcap
For already captured file (capture.pcap):
tcpdump -r capture.pcap | editcap -F libpcap -C 4 - - | tcpdump -nlvvv -r - -w output.pcap
or
editcap capture.pcap output.pcap -C 4
I didn't test these exact examples myself, but I think tshark's "chop" (-C) option might be what you're looking for.
When I ping one site it returns "Request timed out". I want to make little program that will inform me (sound beep or something like that) when this server is online again. No matter in which language. I think it should be very simple script with a several lines of code. So how to write it?
Some implementations of ping allow you to specify conditions for exiting after receipt of packets:
On Mac OS X, use ping -a -o $the_host
ping will keep trying (by default)
-a means beep when a packet is received
-o means exit when a packet is received
On Linux (Ubuntu at least), use ping -a -c 1 -w inf $the_host
-a means beep when a packet is received
-c 1 specifies the number of packets to send before exit (in this case 1)
-w inf specifies the deadline for when ping exits no matter what (in this case Infinite)
when -c and -w are used together, -c becomes number of packets received before exit
Either can be chained to perform your next command, e.g. to ssh into the server as soon as it comes up (with a gap between to allow sshd to actually start up):
# ping -a -o $the_host && sleep 3 && ssh $the_host
Don't forget the notify sound like echo"^G"! Just to be different - here's Windows batch:
C:\> more pingnotify.bat
:AGAIN
ping -n 1 %1%
IF ERRORLEVEL 1 GOTO AGAIN
sndrec32 /play /close "C:\Windows\Media\Notify.wav"
C:\> pingnotify.bat localhost
:)
One way is to run ping is a loop, e.g.
while ! ping -c 1 host; do sleep 1; done
(You can redirect the output to /dev/null if you want to keep it quiet.)
On some systems, such as Mac OS X, ping may also have the options -a -o (as per another answer) available which will cause it to keep pinging until a response is received. However, the ping on many (most?) Linux systems does not have the -o option and the kind of equivalent -c 1 -w 0 still exits if the network returns an error.
Edit: If the host does not respond to ping or you need to check the availability of service on a certain port, you can use netcat in the zero I/O mode:
while ! nc -w 5 -z host port; do sleep 1; done
The -w 5 specifies a 5 second timeout for each individual attempt. Note that with netcat you can even list multiple ports (or port ranges) to scan when some of them becomes available.
Edit 2: The loops shown above keep trying until the host (or port) is reached. Add your alert command after them, e.g. beep or pop-up a window.