Monthly Archives: January 2015

Firefox, Mozilla, Network

Changing networks with Linux

2 Comments

A rather long time ago I blogged about my work to better deal with changing networks while Firefox is running, and the change was then pushed for Android and I subsequently pushed the same functionality for Firefox on Mac.

Today I’ve landed yet another change, which detects network changes on Firefox OS and Linux.

Firefox Nightly screenshotAs Firefox OS uses a Linux kernel, I ended up doing the same fix for both the Firefox OS devices as for Firefox on Linux desktop: I open a socket in the AF_NETLINK family and listen on the stream of messages the kernel sends when there are network updates. This way we’re told when the routing tables update or when we get a new IP address etc. I consider this way better than the NotifyIpInterfaceChange() API Windows provides, as this allows us to filter what we’re interested in. The windows API makes that rather complicated and in fact a lot of the times when we get the notification on windows it isn’t clear to me why!

The Mac API way is what I would consider even more obscure, but then I’m not at all used to their way of doing things and how you add things to the event handlers etc.

The journey to the landing of this particular patch was once again long and bumpy and full of sweat in this tradition that seem seems to be my destiny, and this time I ran into problems with the Firefox OS emulator which seems to have some interesting bugs that cause my code to not work properly and as a result of that our automated tests failed: occasionally data sent over a pipe or socketpair doesn’t end up in the receiving end. In my case this means that my signal to the child thread to die would sometimes not be noticed and thus the thread wouldn’t exit and die as intended.

I ended up implementing a work-around that makes it work even if the emulator eats the data by also checking a shared should-I-shutdown-now flag every once in a while. For more specific details on that, see the bug.

Network, Web

http2 explained 1.8

I’ve been updating my “http2 explained” document every nohttp2 logow and then since my original release of it back in April 2014. Today I put up version 1.8 which is one of the bigger updates in a while:

http2 explained

The HTTP/2 Last Call within the IETF ended yesterday and the wire format of the protocol has remained fixed for quite some time now so it seemed like a good moment.

I updated some graphs and images to make them look better and be more personal, I added some new short sections in 8.4 and I refreshed the language in several places. Also, now all links mentioned in footnotes and elsewhere should be properly clickable to make following them a more pleasant experience. And page numbers!

As always, do let me know if you find errors, have questions on the content or think I should add something!

cURL and libcurl, Mozilla, Network

My talks at FOSDEM 2015

2 Comments

fosdem

Sunday 13:00, embedded room (Lameere)

Tile: Internet all the things – using curl in your device

Embedded devices are very often network connected these days. Network connected embedded devices often need to transfer data to and from them as clients, using one or more of the popular internet protocols.

libcurl is the world’s most used and most popular internet transfer library, already used in every imaginable sort of embedded device out there. How did this happen and how do you use libcurl to transfer data to or from your device?

Note that this talk was originally scheduled to be at a different time!

Sunday, 09:00 Mozilla room (UD2.218A)

Title: HTTP/2 right now

HTTP/2 is the new version of the web’s most important and used protocol. Version 2 is due to be out very soon after FOSDEM and I want to inform the audience about what’s going on with the protocol, why it matters to most web developers and users and not the last what its status is at the time of FOSDEM.

Development, Mozilla, Open Source

My first year at Mozilla

1 Comment

January 13th 2014 I started my fiMozilla dinosaur head logorst day at Mozilla. One year ago exactly today.

It still feels like it was just a very short while ago and I keep having this sense of being a beginner at the company, in the source tree and all over.

One year of networking code work that really at least during periods has not progressed as quickly as I would’ve wished for, and I’ve had some really hair-tearing problems and challenges that have taken me sweat and tears to get through. But I am getting through and I’m enjoying every (oh well, let’s say almost every) moment.

During the year I’ve had the chance to meetup with my team mates twice (in Paris and in Portland) and I’ve managed to attend one IETF (in London) and two special HTTP2 design meetings (in London and NYC).

openhub.net counts 47 commits by me in Firefox and that feels like counting high. bugzilla has tracked activity by me in 107 bug reports through the year.

I’ve barely started. I’ll spend the next year as well improving Firefox networking, hopefully with a higher turnout this year. (I don’t mean to make this sound as if Firefox networking is just me, I’m just speaking for my particular part of the networking team and effort and I let the others speak for themselves!)

Onwards and upwards!

Electronics, Technology

My table tennis racket sized phone

4 Comments

I upgraded my Nexus 5 to a Nexus 6 the other day. It is a biiiig phone, and just to show you how big I made a little picture showing all my Android phones so far using the correct relative sizes. It certainly isn’t very far away from a table tennis racket in size now. My Android track record so far goes like this: HTC Magic, HTC Desire HD, Nexus 4, Nexus 5 and now Nexus 6.

my-androids

As shown, this latest step is probably the biggest relative size change in a single go. If the next step would be as big, imagine the size that would require! (While you think about that, I’ve already done the math: the 6 is 159.3 mm tall, 15.5% taller than the 5’s’ 137.9mm, so adding 15.5% to the Nexus 6 ends up at 184 – only 16 mm shorter than a Nexus 7 in portrait mode… I don’t think I could handle that!)

After the initial size shock, I’m enjoying the large size. It is a bit of a clunker to cram down into my left front-side jeans pocket where I’m used to carry around my device. It is still doable, but not as easy as before and it easily get uncomfortable when sitting down. I guess I need to sit less or change my habit somehow.

This largest phone ever ironically switched to the smallest SIM card size so my micro-SIM had to be replaced with a nano-SIM.

Borked upgrade procedure

Not a single non-Google app got installed in my new device in the process. I strongly suspect it was that “touch the back of another device to copy from” thing that broke it because it didn’t work at all – and when it failed, it did not offer me to restore a copy from backup which I later learned it does if I skip the touch-back step. I ended up manually re-installing my additional 100 or so apps…

My daughter then switched from her Nexus 4 to my (by then) clean-wiped 5.  For her, we skipped that broken back-touch process and she got a nice backup from the 4 restored onto the 5. But she got another nasty surprise: basically over half of her contacts were just gone when she opened the contacts app on the 5, so we had to manually go through the contact list on the old device and re-add them into the new one. The way we did (not even do) it in the 90s…

The Android device installation (and data transfer) process is not perfect yet. Although my brother says he did his two upgrades perfectly smoothly…

cURL and libcurl, Network, Security

curl 7.40.0: unix domain sockets and smb

2 Comments

curl and libcurl curl dot-to-dot7.40.0 was just released this morning. There’s a closer look at some of the perhaps more noteworthy changes. As usual, you can find the entire changelog on the curl web site.

HTTP over unix domain sockets

So just before the feature window closed for the pending 7.40.0 release of curl, Peter Wu’s patch series was merged that brings the ability to curl and libcurl to do HTTP over unix domain sockets. This is a feature that’s been mentioned many times through the history of curl but never previously truly implemented. Peter also very nicely adjusted the test server and made two test cases that verify the functionality.

To use this with the curl command line, you specify the socket path to the new –unix-domain option and assuming your local HTTP server listens on that socket, you’ll get the response back just as with an ordinary TCP connection.

Doing the operation from libcurl means using the new CURLOPT_UNIX_SOCKET_PATH option.

This feature is actually not limited to HTTP, you can do all the TCP-based protocols except FTP over the unix domain socket, but it is to my knowledge only HTTP that is regularly used this way. The reason FTP isn’t supported is of course its use of two connections which would be even weirder to do like this.

SMB

SMB is also known as CIFS and is an old network protocol from the Microsoft world access files. curl and libcurl now support this protocol with SMB:// URLs thanks to work by Bill Nagel and Steve Holme.

Security Advisories

Last year we had a large amount of security advisories published (eight to be precise), and this year we start out with two fresh ones already on the 8th day… The ones this time were of course discovered and researched already last year.

CVE-2014-8151 is a way we accidentally allowed an application to bypass the TLS server certificate check if a TLS Session-ID was already cached for a non-checked session – when using the Mac OS SecureTransport SSL backend.

CVE-2014-8150 is a URL request injection. When letting curl or libcurl speak over a HTTP proxy, it would copy the URL verbatim into the HTTP request going to the proxy, which means that if you craft the URL and insert CRLFs (carriage returns and linefeed characters) you can insert your own second request or even custom headers into the request that goes to the proxy.

You may enjoy taking a look at the curl vulnerabilities table.

Bugs bugs bugs

The release notes mention no less than 120 specific bug fixes, which in comparison to other releases is more than average.

Enjoy!