I plan to use BeagleBone without any of the Linux Distros but with plain bare-metal code.
So first of all: is there already some example-code available for that? Especially a TCP/IP stack for included Ethernet connection?
Thanks!
OK, solved. TI's StarterWare comes with lwip, so everything is there.
Related
I'm trying to find out if there is any native TCP/IP stack implemetation provided in DPDK or any popular open-source project to achieve it. Any help will be grateful.
Update:
My platform is Ubuntu 16.04 x64, Intel 82599es NIC with DPDK 20.08. What I'm trying to accomplish is to rebuild TCP connections out of the packets I receive on the NIC port for later use. I thought tools like ANS, mTCP and fstack may do the track but they are third party and some of them are not fully open-sourced, so I'm looking for a native one or one that is popular for developers. I don't know what should I call this kind of requirement, sorry for troubles causing because of the question, I'll change it after I know the related concept better.
There are no native TCP-IP stack implementation in DPDK version till date DPDK version 20.11 LTS. Going further in my humble opinion DPDK would not be implementing native TCP-IP stack. Hence current options are
Since the requirement is to rebuild TCP connection state information, my recommendation is to
create RTE_FLOW_ACTION_MIRROR to create the packet copy at HW NIC level for all interested TCP connection using a combination of IP-TCP address-ports.
If there is no HW option, either using ref_cnt_update or copying the user packet payload create a copy of the packet.
With help RTE_RINGS or RTE_FB_ARRAY organize the packets from client and server based on symmetric RSS (if available) or based on custom HASH to appropriate containers.
For you packet processing recommendation is either use FSTACK or mTCP or BSD TCP-ip from scratch
there are multiple references on the Internet which gives hints to get started too. Please refer
mTCP slide 14
fstack slide deck
i am doing some simulations of DDOS SYN FLOOD attack on a real network using virtual machines and i want to modify the current behavior of TCP three-way-handshake on Linux Mint, can anyone give me a guide or the steps to do ?
If you want to change the kernel code, then you need to know where they are, and then edit the code, compile them and run. Here is a network can help you know how to do these things, but the knowledge of Linux network stack is not include.
Would a Tun/tap device avoid a netmap/pf_ring/dpdk installation ? If tun/tap allow to bypass kernel, isn't it the same thing ?
Or those codes bring so many optimizations that they overclass tun os bypass strategy ?
The final goal is to port tcp/ip from kernel to user space, FOR TESTING PURPOSES.
I don't quite understand here.
Thanks
no.
for userspace tcpip implementation see lwip or rumpkernel.
dpdk/pfring/netmap as you probably know are about getting packets to userspace as fast as possible.
tun/tap are virtual interface things. probably not what you're after.
Tun/tap are not particularly performant. They miss out on the IP stack, but there is a lot of copying still involved. Profile some code using them to see. I think the best option for straight userspace networking is probably AF_PACKET using the ring buffer option, but that will is still an indirect ring buffer that gets copied to the network card ring buffer rather than being direct like you get with solutions like dpdk. It depends on your performance requirements - if it is just for testing correctness any solution should be fine.
Hi Guys I'm debugging some CS program and to view the performance of the application in slow internet I tried many different ways. However the best would be the Server and the client be in the same PC ---- my debugging environments for both the server side and the client is setup in one PC.
So I'm wondering is there anyway to limit the speed? I'm using TCP but I don't know too much in-depth knowledge of it.
Thank you
There are two important factors regarding a "slow" internet connection that you need to test out since they have different implications for your application: bandwidth and latency.
If you provide some more details about what os you are running your tests on, it would be easier to recommend a way to limit the network performance.
On a related side note, it's generally a bad idea to performance test any kind of networking using the loopback device on your machine, since many aspects of this will perform very different than the regular network device on your machine.
You mention in the comments this needs to be done on windows, while the Network Emulators I know of (e.g. netem, TCN, other variants) all require Linux. So one thing you could do is create a virtual machine (VirtualBox is fine, I did similar things with it), install linux on it, configure 2 network interfaces, emulate the slow/long/lossy/jittery network between them, and route the test traffic through it from windows.
Finally I found this does what I need.
http://www.nirsoft.net/utils/socket_sniffer.html
Captures Windows Socket traffic, no matter it's local or not.
I'm talking about http://en.wikipedia.org/wiki/Quality_of_service. With streaming stackoverflow podcasts and downloading the lastest updates to ubuntu, I would like to have QoS working so I can use stackoverflow without my http connections timing out or taking forever.
I'm using an iConnect 624 ADSL modem which has QoS built-in but I can't seem to get it to work. Is it even possible to control the downstream (ie. from ISP to your modem)?
I don't know if this will help you, but I've never been a fan of using the ISP provided box directly. Personally I use a Linksys wrt54gl, with DD-wrt, behind(DMZ) my ISP provided box.
DD-wrt has excellent QoS management.
Sorry I can't be more help with your existing hardware.
You just need the tc command to handle the QoS on Linux boxen. However I wouldn't expect that much from it because of the results I obtained and detailed here.