eLua network stack
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Hello guys,
I was looking for eLua network capabilities to use in a project and I found it's using uIP for that. I have read that uIP has evoluted to iwIP, that is actively developed and has no performance issues compared to uIP.
Other thing I have seem is that eLua net module is experimental, only supports SOCK_STREAM for TCP, no UDP, etc. Would be a pain to switch to iwIP since it has more capabilities than uIP, that could extend featuresin eLua net module and make it more stable?
I thought about doing that by myself as soon as I know more the eLua internal, but I found that could be a good idea come here and discuss with you firstly. _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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Ahhh I forgot to add:
There is some problem with the license of lwIP, if it's added to eLua code? It uses Modified BSD license.
Cheers!
2013/3/18 Gabriel Duarte <[hidden email]> Hello guys, -- Gabriel Duarte Linux User #471185Rio de Janeiro / RJ http://genericdev.wordpress.com/ _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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In reply to this post by gduarte
Hi,
I was able to use LwIP raw tcp api and matrixSSL with eLua on at91sam7x512 port. In my case, the TCP server is calling lua scripts to execute, what is different as uIP net module. But don't see big problem with making lua network module for lwip. probably the hardest/tricky part is blocking read from network. I implemented even the write to the network s blocking, so your script is halted until other site do not send ACK on your data. It is a little bit platform depended and probably not the best for client applications, but I think is perfect for servers. Do you need network server or client support? which platform are you using? I plan to publish my project to open source community as soon as it will be published in school what could be in April or May. On Mar 19, 2013, at 2:46 AM, Gabriel Duarte wrote: Hello guys, _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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In reply to this post by gduarte
On 19 March 2013 01:46, Gabriel Duarte <[hidden email]> wrote:
> I was looking for eLua network capabilities to use in a project and I found > it's using uIP for that. I have read that uIP has evoluted to iwIP, that is > actively developed and has no performance issues compared to uIP. That would be excellent. I have found that uip is OK as long as you send it a few bytes every noe and then, but if you try to transfer data at the maximum rate, leaning on the flow control, it slows down to 1 byte per second. At least, I assume that's uIP. THe behaviour was observed on AVR32 port, but I haven't been able to test the behaviour on other platforms and no one replied when I asked about it at the time. > Other thing I have seem is that eLua net module is experimental, only > supports SOCK_STREAM for TCP, no UDP, etc. Would be a pain to switch to iwIP > since it has more capabilities than uIP, that could extend featuresin eLua > net module and make it more stable? Well, providing the limited TCP functionality that eLua already supports should make your task easier. Extending that to UDP means having to invent more eLua-specific primitives in eLua's "net" module Another direction to take would be to leave the existing net interface as it is, and make the eLua interface to LWIP compatibile with luasocket, which saves you having to invent an interface to UDP, ICMP and the rest, is sure to be an interface that can do everything, and would allow eLua users to use the hundreds of Lua libraries that depend on luasocket. On the one hand, it means taking on two projects instead of one, but on the other it might be easier to achieve. Presumably, when LWIP works on all platforms, either "net" could be reimplemented as an compatability interface to luasocket (and probably in Lua!) or left as yet another alternative-compilation-option, if LWIP turns out to be significantly larger than uIP. M _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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In reply to this post by gduarte
On 19 March 2013 01:49, Gabriel Duarte <[hidden email]> wrote:
> Ahhh I forgot to add: > > There is some problem with the license of lwIP, if it's added to eLua code? > It uses Modified BSD license. > http://en.wikipedia.org/wiki/LwIP The only extra condition is: * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. So putting the BSD licence, referred to the LWIP component, in some text file included with binary dists will be enough. M "We are riding the wavefront of technology And behind the wavefront is a trough And the trough is full of lawyers." _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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In reply to this post by gduarte
Hi,
On Tue, Mar 19, 2013 at 3:46 AM, Gabriel Duarte <[hidden email]> wrote: Hello guys, That's only partially correct. uIP didn't quite evolve to lwIP, they are different stacks with different capabilities and quite different memory requirements (which is why eLua uses uIP at the moment).
This is something we take under consideration, but no final decision was made yet.
By all means, please do it. While you're at it, you can also suggest ways to improve our platform interface and overall network API, since that's an area where eLua needs a lot of improvement. Best, Bogdan
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In reply to this post by Lukas Kacer
On 19 March 2013 03:03, Lukas Kacer <[hidden email]> wrote:
> I was able to use LwIP raw tcp api and matrixSSL with eLua on at91sam7x512 > port. ! > In my case, the TCP server is calling lua scripts to execute !! > I implemented even the write to the network s blocking, so > your script is halted until other site do not send ACK on your data. How do you inplement the extra interfaces at a Lua level? Extensions to the "net" module? Or do you just implement the existing "net" interface? > It is a > little bit platform depended and probably not the best for client > applications, but I think is perfect for servers. > Do you need network server or client support? which platform are you using? Speaking from a developer point of view, that is not a problem to consider when designing a new network interface because people will want clients, servers, client-servers, and on all platforms. The interface must allow everything that people might want. > I plan to publish my project to open source community as soon as it will be > published in school what could be in April or May. I can't wait! If you can arrive earlier that is good, as it will maybe save us some time. M _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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@martinguy
Good you liked! I been talking to people who already have use uIP with eLua and they said that it gets confused and slow when it tries to open more than 3 or 4 sockets, so, that's a big problem from point of view. At first, we could provide only TCP functionality, but with no issues from uIP. Extending to UDP would be a big step, but I think that TCP is more important at the moment and then after we can think about how to extend the net modulo to fit UDP features.
You had the SAME idea I had yesterday. Make luasocket compatible with lwIP, that could REALLY extend the eLua network features. You said that lwIP could turns out to be significantly larger than uIP, but I think that today our hardware is not as limited as it was few years ago, either in RAM and ROM size, etc, so, I think that we could put lwIP as a replacement to uIP if it proves it's better in many aspects.
About the license, good that there's no problem in adding it to eLua. @Bogdan Sorry, my mistake.. I said it's an evolution from uIP, but they just started being developed by the same guy, but not derivated from each other. You really think that now, at these days we still have so memory problems to room lwIP? The lwIP wiki says: "The focus of the lwIP TCP/IP implementation is to reduce resource usage while still having a full scale TCP. This makes lwIP suitable for use in embedded systems with tens of kilobytes of free RAM and room for around 40 kilobytes of code ROM."
I will try to start something, at least compile lwIP, since I really new to eLua and the embedded world.
@Lukas Kacer Please, share you us your work, as Martin said, could save a lot of time :) I am really interested in :) Best regards, Gabriel
2013/3/19 martinwguy <[hidden email]>
-- Gabriel Duarte Linux User #471185Rio de Janeiro / RJ http://genericdev.wordpress.com/ _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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In reply to this post by Martin Guy
On Mar 19, 2013, at 12:18 PM, martinwguy wrote: > On 19 March 2013 03:03, Lukas Kacer <[hidden email]> wrote: >> I was able to use LwIP raw tcp api and matrixSSL with eLua on at91sam7x512 >> port. > > ! > >> In my case, the TCP server is calling lua scripts to execute > > !! > >> I implemented even the write to the network s blocking, so >> your script is halted until other site do not send ACK on your data. > > How do you inplement the extra interfaces at a Lua level? Extensions > to the "net" module? > Or do you just implement the existing "net" interface? The script execution is driven by events in the network. it's working like this: Bind to network port is done in different script (or C startup code) than the network read and write functions. The script with read/write functions is executed when new connection appears from callback function called from lwIP. the only problem with this is, that you need to exit that callback function and return to lwIP to read more data or make real write to network. you can call lwip tcp_send() but that data will be buffered and will leave tcp/ip stack after return from callback. To solve this I do setjmp(parent); setjmp(child); child[x] = malloc(stack_size) before executing script and from in module.write/read functions I do setjmp(child); longjmp(parrent). this "pauses" execution of script until you get ACK from client on sent data or you have new data to read. setjmp(child); child[x] = malloc(stack_size) is creating new stack for lua script that will be executed. it's platform depended, but it is not something hard to do. you just net to find out where setjmp save register with stack address. it is a little bit more complicated I'm my code, as I have also matrixSSL between lwIP and lau script. And the lua script is in my case WSAPI, which I had to partially rewrite to C, because I was running out of memory. > >> It is a >> little bit platform depended and probably not the best for client >> applications, but I think is perfect for servers. >> Do you need network server or client support? which platform are you using? > > Speaking from a developer point of view, that is not a problem to > consider when designing a new network interface because people will > want clients, servers, client-servers, and on all platforms. The > interface must allow everything that people might want. Speaking from a developer point of eLua yes. But I wanted to know if he wants network support for some specific project and if it's close to my one, I would be able to help him. I know that a lot of users would love to see clients, servers, client-servers support and the best to port apps to eLua is luasockets, but I not sure if socket API is the good one for eLua and would not be much easier and effective to create just some kind of wrappers for lwIP. From what I see, in actual eLua net module(which is socket based) is impossible to create server(s) unless you want to read with timeout in loop from all sockets that you opened. And in C code of net module you then do loop read until you read something or timeout expires if I remember it right. And as it is embedded system, we should care about that as it can be problem for some users/devices/applications. > >> I plan to publish my project to open source community as soon as it will be >> published in school what could be in April or May. > > I can't wait! If you can arrive earlier that is good, as it will maybe > save us some time. not sure if you/anyone should wait for that. I think now that your goal is probably different from what my project does. When I was choosing/creating the theme more than year ago, I wanted to create some real value to the community. But now I see it moved to totally different direction and I'm not sure if it is wort of something (besides one fixed bug in matrixSSL api) and all I want is finally publish it == finish school and get a real job. Lukas > > M > _______________________________________________ > eLua-dev mailing list > [hidden email] > https://lists.berlios.de/mailman/listinfo/elua-dev _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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You could at least show how to compile lwIP and connect it to eLua :)
2013/3/19 Lukas Kacer <[hidden email]>
-- Gabriel Duarte Linux User #471185Rio de Janeiro / RJ http://genericdev.wordpress.com/ _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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I was thinking that I would upload my project (with all the mess) to dropbox and
send link to all of you who are interested if you will promise that you will not publish it new few months. So anyone who wants it now can send me direct email. I will try to upload it this evening. On Mar 19, 2013, at 15:49 PM, Gabriel Duarte wrote: You could at least show how to compile lwIP and connect it to eLua :) _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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Please, do it :-)
Thank you very much!
2013/3/19 Lukas Kacer <[hidden email]>
-- Gabriel Duarte
Linux User #471185Rio de Janeiro / RJ http://genericdev.wordpress.com/ _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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Gabriel, did you get that message with dropbox link and short description of the code I sent directly to your email address?
On Mar 20, 2013, at 20:00 PM, Gabriel Duarte wrote: Please, do it :-) _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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Hello Lukas, I will grab the code tonight. Dont worry, I will not publish the code without our authorization! Thank you very much! 2013/3/21 Lukas Kacer <[hidden email]>
-- -- Gabriel Duarte
Linux User #471185Rio de Janeiro / RJ http://genericdev.wordpress.com/ _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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Grabbed! I will take a look now!
Thanks again!!!
2013/3/21 Gabriel Duarte <[hidden email]>
Gabriel Duarte Linux User #471185Rio de Janeiro / RJ http://genericdev.wordpress.com/ _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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I took a look at eLua's source code to know how eLua interfaces with uIP.
I saw that net module uses functions described into elua_uip.c, right? So, in theory, if I implement the eLua net module calls using lwIP, should just work, right?
I know it's not that, but the flow is correct at least? Cheers
2013/3/22 Gabriel Duarte <[hidden email]> Grabbed! I will take a look now! Gabriel Duarte Linux User #471185Rio de Janeiro / RJ http://genericdev.wordpress.com/ _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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On 22 March 2013 22:48, Gabriel Duarte <[hidden email]> wrote:
> I took a look at eLua's source code to know how eLua interfaces with uIP. > I saw that net module uses functions described into elua_uip.c, right? If I remember correctly, yes, but it doesn't end there. For uIP, those then call functions in src/platform/*/platform.c called platform_ethernet_setup(), platform_eth_send_packet() and so on, as well as having a timer running in the background to do something periodically - probably to service timeouts and to retry lost packets, but have a look at what it is used for in uIP. If you are lucky, the platform_ethernet_*() functions and the timer will allow you to implemented them on top of lwIP, but only if you are lucky. Note that they depend on #ifdef BUILD_UIP, which turns the whole NET/ETHERNET subsystem and eLua module on and off, so you will also have to split all BUILD_UIP-dependent code into what is BUILD_UIP-specific, what is BUILD_LWIP-specific and what is BUILD_NET-specific. You can probably assume that BUILD_NET == BUILD_UIP || BUILD_LWIP, and that only one of BUILD_UIP and BUILD_LWIP can ever be defined at the same time. Note that there is also the option to have the eLua console on a telnet port, which is a different route to the platform_ethernet_*() functions, in addition to the Lua net.*() functions. Have a look at that path through the code also - my feeling it that is probably won't cause problems, but might help you understand the code structure, to see two different users of the ethernet subsystem. > So, in theory, if I implement the eLua net module calls using lwIP, should > just work, right? Oh, in theory, yes, everything should always just work. That's why computer programming is so easy. :) M _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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Hi. I'm looking at elua_uip_mainloop in elua_net.c function for a while and don't understand one thing. Why is almost at the end the for loop that calls uip_periodic executed also when periodic_timer < UIP_PERIODIC_TIMER_MS ? uIP documentation says about uip_periodic: "should be called when the periodic uIP timer goes off" so if I'm not missing something, it is ineffective to do that for loop after every received packet. But still it is not wrong. can it be that this is affecting the bad behavior with more opened sockets and executing that for loop just if periodic_timer >= UIP_PERIODIC_TIMER_MS would partially speed up things. Can someone look at it if I'm right? Lukas _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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Lukas, do you plan to merge your lwIP port to eLua? Cheers! 2013/4/27 Lukas Kacer <[hidden email]>
Gabriel Duarte
Linux User #471185Rio de Janeiro / RJ http://genericdev.wordpress.com/ _______________________________________________ eLua-dev mailing list [hidden email] https://lists.berlios.de/mailman/listinfo/elua-dev |
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Hi Gabriel. I don't fully understand what you meant by "merge", so here is my plan. I plan to put my work to git at 15th May or maybe before. (that is my deadline for thesis. )Based on that work should be anybody able to use lwIP with existing eLua "Ethernet driver" for other platforms with small changes. but I think that my solution isn't best and can be improved. I don't use lwIP to do network communication from lua script as it was with uIP and lua net module. I use lwIP raw API and matrixSSL library to make simple HTTPS server. that server can run lua scripts in which you can theoretically receive and send as manny data as you want. I have some plans with making some network module for eLua that will use lwIP, but don't know when and it will probably not be close future. or maybe I will try do something based on existing eLua net using lwIP and matrixSSL. Lukas On May 2, 2013, at 19:16 PM, Gabriel Duarte wrote:
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