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Raphters, a web framework for C
- deleted 16y ago[deleted]
- deleted 16y ago[deleted]
- rbranson 16y agoThis is neat. Honestly, in addition, I'd like to see something like Rack for C. The "gateway interfaces" for C are too implementation-specific (CGI, FastCGI, SCGI, web server extensions/modules, etc). It would be something more abstract that would run on-top of a web server interface. void application_main(web_request *request, web_response *response) { char body[1024]; snprintf(body, sizeof(body), "Hello, %s", request->param("username")); response->status(200); response->header("Content-Type", "text/html"); response->write(body); response->end(); }
- roel_v 16y agoRather: response_set_status(200); response_set_header("Content-Type", "text/html"); response_write(body); response_end(); The awkwardness of which, to me, demonstrates the superiority of C++ in this regard.
- rbranson 16y agoYeah that's what I get for being in the OOP world for the daily grind. I think a C API is still definitely for the best. Perhaps a nice shortcut API for this would be something like: response_complete(200, body, response_header("Content-Type", "text/html"));
- jerf 16y agoThat implies some global state somewhere being updated, and now you've given up on threading. This may be OK, but it's still dangerous and leaky even if you give up on threading. There are various solutions that still allow you to pass a set of closures without being particularly more ugly than anything else is in C, for instance, see http://library.gnome.org/devel/gobject/stable/chapter-signal.html#closure http://library.gnome.org/devel/gobject/stable/chapter-signal... . C++ still ends up nicer, my point is just that you can do good things in C and there are libraries that implement the stuff for you. That said, if I were really going this route I probably would try to go with some sort of minimal C++. Then again, my opinion is suspect, as I would never go this route anyhow. Web developers writing in languages that don't permit buffer overflows write software that has all the security of a colander; adding the ability to write good, solid buffer overflows as well hardly seems like a step up. You can write secure C code, but you can write secure PHP code, too. Existence proofs of secure code aren't very interesting.
- DanWaterworth 16y agoYou're right, web developers already write software with all the security of a colander. You can go one of two ways, 1.) you can devise a language that can't express an insecure application or 2.) you can teach people about security. I know which option I prefer.
- jerf 16y agoI assume you mean #2? Because here we are in year, oh, 17 or 18 or so of web development give or take a couple of years and that's worked out so well, hasn't it? It's a beautiful sentiment. It hasn't worked. Handing them new vectors to screw up in is not going to solve the problem. It also doesn't matter. Hand a developer a tool that requires them to continuously pay attention to an issue and no matter how good they are, at some point they will slip, because they're human. We've tried "teach them about security" a couple hundred times, maybe it's time we try "devise a language that can't trivially express an insecure application". C will not be the language that implements that, it completely lacks any of the necessary primitives, by design.
- tptacek 16y agoOverly reductive. There is an actual security benefit to using environments that minimize memory corruption. Educating devs helps, but educated devs do not reliably avoid memory corruption.
- bdonlan 16y agoThey don't have to be global state - they can be updating thread local state, for example, in what is essentially dynamic scope. Depending on the OS, the efficiency of such TLS accesses can be quite good - on Linux, for example, it's just an extra pointer indirect or two with a segment selector (assuming the code is statically linked; it's very slightly more expensive in a solib).
- jerf 16y agoTouche. It's still an API design that's going to prove problematic, though.
- tptacek 16y agoYou're only a couple function pointers away from the syntactic sugar of the -> operator.
- VladRussian 16y agoin correct functional style shouldn't it rather be : response_set_status(response, 200); no issues with global state, threading (if correctly mutexed), etc...
- rubashov 16y agoAll the pieces to do the whole framework are already in POCO and other libraries, with ssl and cookies etc. http://pocoproject.org/docs/Poco.Net.HTTPResponse.html http://pocoproject.org/docs/Poco.Net.HTTPResponse.html http://pocoproject.org/docs/Poco.Net.html http://pocoproject.org/docs/Poco.Net.html Doing this in C seems silly to me.
- roel_v 16y agoWell yes it should have been response_set_status(handle, 200); My point was that the syntax in the example was C++.
- DanWaterworth 16y agoIt would be possible to support other gateway interfaces in raphters. The abstractions already exist.
- sigil 16y ago> The "gateway interfaces" for C are too implementation-specific (CGI, FastCGI, SCGI, web server extensions/modules, etc). It would be something more abstract that would run on-top of a web server interface. Yes. My preference in web apps (esp in C) is also to deal directly with http requests and responses. Although I wouldn't necessarily call that the "more abstract" approach. To an extent, each of these gateway interfaces is a different leaky abstraction for http.
- tptacek 16y agoAs an illustration of why C kind of sucks for web apps, that code is obviously insecure† (it's reflected XSS). To get around that while preserving natural syntax, you want: char *hsafe(const char *input); But where does hsafe get the memory for the string from? It can't use input (the filtered result is larger than the input). Does it malloc? Now you have to free the result. Does it do the inet_ntoa() thing with the static variable? Now you can't chain it (or use threads, but you wouldn't want to do that anyways). Maybe you can do an arena for each connection, so it's: char *hsafe(request_t *r, char *str) But that's still sort of painful. † In an admittedly artificial way.
- nkurz 16y agoI'm not seeing this a problem with C, but perhaps I misunderstand. Your goal is avoid including anything executable in the page. The filtered result is only larger than the input if you need the ability to faithfully quote the potentially malicious code. In this particular contrived example, you could "just" strip it out and make it shorter, or even error out if you see anything suspicious. Which is to say it's only a problem if you are doing it by hand on a per field basis. Which leads to your next point: > Maybe you can do an arena for each connection, so it's: > char *hsafe(request_t *r, char *str) > But that's still sort of painful. This is only painful if you are doing it by hand every time you use the parameter. If the framework handles it for you, so that you always get the sanitized result, it strikes me as no different than any other language. r->param("input"); // presanitized, lazily created, pooled in r r->param_raw("input"); // if you want to live dangerously Why is this worse in straight C than in something like Python that is doing the same thing but with an interpreted layer between you and the C?
- tptacek 16y agoYou need to convert < into <. That's the price of entry. You can't redefine the problem to "web framework that simply strips < out of inputs". Your framework would then be immediately inferior to every other framework which does output quoting.
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- rch 16y agoYou might look here before starting from scratch in C: http://okws.org http://okws.org (C++)
- compay 16y agoIt would be neat to see how you could possibly hook Lua into this to give you some of the flexibility of a dynamic language with the speed and small footprint of a (mostly) C app. I've been thinking of working on something like that for a while but unfortunately my C skills need a lot more work before I'd be comfortable tackling it.
- lhorie 16y agoHave you looked at Tir? http://tir.mongrel2.org/home http://tir.mongrel2.org/home
- compay 16y agoYeah, I wrote the test framework that Zed uses for Mongrel2 and Tir's unit tests, and also wrote the WSAPI handler for Mongrel2 (a separate project from Tir). What I'd really like to see is not so much a web framework in Lua (there are a few, I'm working on another one, and it's really not hard to make one either), but rather one that's mostly C but lets you use Lua, say, for templates or controller functions. That could be pretty interesting for very small devices, or for squeezing lots of performance out of a larger one, all while stilling letting you program the bulk of your code in a higher level language.
- DTrejo 16y agoCame across this the other day: Embed the Power of Lua into NginX https://github.com/chaoslawful/lua-nginx-module https://github.com/chaoslawful/lua-nginx-module
- 1337p337 16y agoThere's also AbsoLUAtion for Lighttpd. Lua's a very nice, convenient language for embedding dynamic/user-configurable bits in otherwise static applications. PowerDNS and nmap use it, too. It seems to have displaced Tcl as the de facto language for embedding.
- ay 16y agoLuajit2 approaches C on speed [1] - and with the newly released FFI library the C is not really needed that much - so, pretty much all the work has been already done. Just use the results of it :) [1] http://news.ycombinator.com/item?id=641313 http://news.ycombinator.com/item?id=641313
- ognyankulev 16y agoThis framework does almost nothing. I don't see the point of it.
- redredraider 16y agoReinventing the wheel for lulz...
- dasil003 16y agoThe point is that with sufficient pathology you can do high-level things in a low-level language, but not the inverse.
- tkahn6 16y agoThat's not exactly true though. Here's an example: http://www.arduino.cc/playground/Interfacing/Python http://www.arduino.cc/playground/Interfacing/Python
- jrockway 16y agoToo bad the point isn't true? I've write code that looks nearly identical to C in Haskell all the time. (Except, of course, that `alloca` is faster than malloc and is garbage-collected.)
- tptacek 16y agoInteresting, but very minimal. It's basically a wrapper around FCGI (meaning it's doing the old-school "pull request data out of environment variables" thing) with a linked list of regexes matching handlers. That's not nothing; "registered list of regexes matching handlers" is a proven good model for web frameworks and it's handy to have. On the other hand, if I was going to release a web framework, I might do more to abstract request variables (provide a params hash like Rails, or a Rack-style request hash). Also: I'd probably build it on libevent's evhttp instead of demanding that users plug my C code into FCGI.
- DanWaterworth 16y agoNothing is set in stone. I do admit that a libevent based asynchronous API is tempting.
- JoachimSchipper 16y agoSomething like evhttp also has the benefit that you can have more than one request "in flight". FastCGI can theoretically do this, but almost no implementation supports it - and it makes e.g. writing a simple chat server much easier (one process, one thread, tons of connections, data in memory.)
- tptacek 16y agoThe downside to doing evhttp is that he'll have to write his own request parsing (I think he's relying on Apache/CGI to do that for him now). But if you're going to do a C web framework (and... really? you sure about that?), that's probably how you should do it.
- sigil 16y ago> The downside to doing evhttp is that he'll have to write his own request parsing... Which, these days, isn't a huge deal. Both of these are decent: https://github.com/ry/http-parser https://github.com/ry/http-parser https://github.com/mongrel/mongrel/blob/master/ext/http11/http11_parser.rl https://github.com/mongrel/mongrel/blob/master/ext/http11/ht...
- ignifero 16y agoVery refreshing, a time tunnel straight to 1994.
- sunkencity 16y agoPretty cool, but if I really had to write some kind of C stuff to output web pages I suppose I'd just build it as an apache module rather than go the CGI route, there's lots of useful functions and nifty stuff within apache making it a pretty nice environment for serving stuff. (Or more probably since it's 2011, I'd try an nginx module (or lightty), although I have never looked at any of those projects code yet). Building response stuff in C is pretty high maintenance stuff though.
- chuhnk 16y agoFunnily enough this was going to be my starting point into writing a C webapp. I felt that by writing a C module directly embedded in an existing web server it would allow me to leverage the request handling. Having already done bugfixes for apache C modules are work it felt the most relevant path to take. The problem I see with it though is you are bound to the webserver you write the module for. Portability would be nice.
- jamesshamenski 16y agoThe title is like saying, 'running shoes for grandma'.
- deleted 16y ago[deleted]
- burrows 16y agoThere was some issues with the code. Mostly memleaks. I think I've fixed most of them, although it was tough to do so elegantly. You may want to rethink using the START_HANDLER macro (or at least restructure it) as it makes it difficult to correctly handle errors with writing a response. I've addressed this issue in RAPHT and offered a fix. However I think I complete rework is of that subsystem is probably better. I'm at work so I can't setup a server to test, however after summoning my inner compiler my changes seem sane. But you should look them over (check the pull on github https://github.com/DanielWaterworth/Raphters/pull/2 https://github.com/DanielWaterworth/Raphters/pull/2). I'll be around if you want to discuss a proper fix for some of the issues. Albeit it will take a pretty major rewrite.
- swah 16y agoCan't we just have a minimal webserver for ZeroMQ, and from there all the languages with ZeroMQ bindings?
- wingo 16y agoI thought at first that this was named for Raph Levien (http://en.wikipedia.org/wiki/Raph_Levien http://en.wikipedia.org/wiki/Raph_Levien) who wrote Advogato in C, some 10+ years ago. But no mention of that in the README or RAPHT. Too bad :)
- DanWaterworth 16y agoUntil you mentioned him I never even knew he existed.
- joelmichael 16y agoA couple of years ago, I also embarked on a mad project to create a web framework in C. I wrote a scandalous and regrettable blog post about it which got on Hacker News and I have since taken down. You can find what remains of the unfinished project here: https://github.com/joelmichael/memereap https://github.com/joelmichael/memereap
- antihero 16y agoAnd still, be blocked by IO.
- supervillain 16y agoThis is awesome, reminds me of the days of writing CGI apps in bash.