Tag Archive for 'Tech'

Sweden: forward thinking and clear thinking are not mutually exclusive

Published
by
spacehunt
on Tue, 30 Jan 2007
in English
. 0 Comments

Second Life may be the most hyped up virtual world around, but this is just ridiculous [The Age]:

Sweden plans embassy in Second Life Sweden is to become the first country to establish diplomatic representation in the virtual reality world of Second Life, officials said. “We are planning to establish a Swedish embassy in Second Life primarily as an information portal for Sweden,” Swedish Institute (SI) director Olle Waestberg has told AFP.

If I am a Swede I’m not sure if I want my country to be associated with what appears to be the online haven for money laundering and pyramid schemes.

iPhone

Published
by
spacehunt
on Tue, 30 Jan 2007
in English
. 0 Comments

Regarding the iPhone I’ll continue to reserve judgement until after more details are available, which is unlikely before its release in the US in June. But suffice to say, I won’t be getting it until it supports WCDMA. Simply because, without WCDMA, the phone cannot roam in Japan.

Streaming TV using VLC

Published
by
spacehunt
on Wed, 26 Jul 2006
in English
. 0 Comments

In case I forget, following is the command I am using to stream from a Hauppauge PVR-250 card via HTTP… so that I can watch Hong Kong television from elsewhere, in case I get nostalgic or something:

spacehunt@ramen:~$ vlc -v --color pvr:/dev/video0:size=720x576:bitrate=3000000 --cr-average 1000 --sout '#transcode{vcodec=mp4v,acodec=vorbis,vb=180,ab=48,width=320,height=240,venc=ffmpeg{keyint=80,hurry-up,vt=500000},deinterlace}:standard{access=http,mux=ogg,dst=:56881}'

This says, take a 720×576 3Mbps MPEG2 stream from /dev/video0, deinterlace, transcode it using the XViD and Vorbis codecs, at 180kbps and 48kbps respectively, scale the resolution down to 320×240, and offer the result via HTTP port 56881 as an Ogg stream.

At first I tried Flumotion… but after trying for the whole morning, I gave up and remembered that VideoLAN was created exactly for this purpose. And it works flawlessly!

“Man-in-the-Middle” is an understatement

Published
by
spacehunt
on Fri, 9 Jun 2006
in English
. 2 Comments

So we thought one way to defeat the bloody GFW is to just silently drop all RST flagged packets, which is very simple to do with Linux and iptables.

Continue reading ‘“Man-in-the-Middle” is an understatement’

The Legendary Great Firewall of China

Published
by
spacehunt
on Fri, 9 Jun 2006
in English
. 5 Comments

Over the past month, our colleagues in mainland China have been complaining about not being able to connect to our email server, which is located in Hong Kong. Connecting to ports 25 (SMTP), 143 (IMAP4), 110 (POP3), 80 (HTTP), 443 (HTTPS) and 22 (ssh) often results in an immediate ‘Connection closed by foreign host.’

Well, not quite immediate… often some bits can be passed through, for example:

# telnet mail.sw-linux.com 143
Trying 202.153.106.243...
Connected to mail.sw-linux.com.
Escape character is '^]'.
* OK [CAPABILITY IMAP4rev1 UIDPLUS CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT IDLE ACL ACL2=UNION STARTTLS XMAGICTRASH] Courier-IMAP ready. Copyright 1998-2004 Double Precision, Inc.  See COPYING for distribution information.
Connection closed by foreign host.

# telnet mail.sw-linux.com 25
Trying 202.153.106.243...
Connected to 202.153.106.243.
Escape character is '^]'.
220 mail.sw-linux.com ESMTP Exim 3.35 #1 Fri, 09 Jun 2006 13:14:12 +0800
HELO nanjing
250 mail.sw-linux.com Hello nanjing [218.104.86.222]
MAIL FROM: xxxx@sw-linux.com
250 <xxxx @sw-linux.com> is syntactically correct
RCPT TO: xxxx@sw-linux.com
250 <xxxx @sw-linux.com> is syntactically correct
Connection closed by foreign host.

So what do we do? Let’s do a trace of the actual TCP/IP packets, courtesy of ethereal. Here’s what our Hong Kong server sees:

Capturing on eth0
  0.000000 218.104.86.222 -> 202.153.106.243 TCP 39758 > smtp [SYN] Seq=0 Ack=0 Win=5840 Len=0 MSS=1460 TSV=92231345 TSER=0 WS=6
  0.000811 202.153.106.243 -> 218.104.86.222 TCP smtp > 39758 [SYN, ACK] Seq=0 Ack=1 Win=5792 Len=0 MSS=1460 TSV=15684968 TSER=92231345 WS=7
  0.102624 218.104.86.222 -> 202.153.106.243 TCP 39758 > smtp [ACK] Seq=1 Ack=1 Win=5888 Len=0 TSV=92231453 TSER=15684968
  0.103506 218.104.86.222 -> 202.153.106.243 TCP 39758 > smtp [RST] Seq=1 Ack=1302803663 Win=0 Len=0
  0.190447 218.104.86.222 -> 202.153.106.243 TCP 39758 > smtp [RST] Seq=1 Ack=1 Win=0 Len=0
  0.231670 218.104.86.222 -> 202.153.106.243 TCP 39758 > smtp [RST] Seq=1 Ack=1 Win=0 Len=0

And from our Nanjing client:

Capturing on eth0
  0.000000 218.104.86.222 -> 202.153.106.243 TCP 39758 > smtp [SYN] Seq=0 Ack=0 Win=5840 Len=0 MSS=1460 TSV=92231345 TSER=0 WS=6
  0.107777 202.153.106.243 -> 218.104.86.222 TCP smtp > 39758 [SYN, ACK] Seq=0 Ack=1 Win=5792 Len=0 MSS=1460 TSV=15684968 TSER=92231345 WS=7
  0.107813 218.104.86.222 -> 202.153.106.243 TCP 39758 > smtp [ACK] Seq=1 Ack=1 Win=5888 Len=0 TSV=92231453 TSER=15684968
  0.234913 202.153.106.243 -> 218.104.86.222 TCP smtp > 39758 [RST] Seq=1 Ack=1 Win=0 Len=0
  0.269906 202.153.106.243 -> 218.104.86.222 TCP smtp > 39758 [RST] Seq=1 Ack=1 Win=0 Len=0

Now I’m no networking expert, but look at all these packets with the RST flag set… no wonder the connection drops. Even more strangely, look at the line I bolded; that Ack number seems to have came out of nowhere.

Man-in-the-middle, perhaps?

So this morning at around 11am, we opened another set of ports with non-standard port numbers for our mainland colleagues to use. It worked… while it lasts; even these ports were blocked by around 12:20pm ten minutes later.

What can we do?

Update Duh, this is very likely due to the enforcement of the new anti-spam legislation.

Someone Doesn’t Like Google.cn

Published
by
spacehunt
on Wed, 22 Feb 2006
in English
. 0 Comments

No, this isn’t really about Google.cn not having a legal ICP license. Someone just doesn’t like what they have done, especially in how they are telling users they are censored (emphasis mine):

But the China Business Times, a business newspaper with a sometimes nationalist slant, blasted Google for even telling people that links are censored. “Does a business operating in China need to constantly tell customers that it’s abiding by the laws of the land?” it said, adding that Google had “incited” a debate about censorship. The paper likened Google to “an uninvited guest” telling a dinner host “the dishes don’t suit his taste, but he’s willing to eat them as a show of respect to the host.”

Yes it’s all about face-giving. Go ahead and close it down I say. People still uses the uncensored Google.com instead anyway.

What’s Wrong With You Steve?

Published
by
spacehunt
on Wed, 11 Jan 2006
in English
. 4 Comments

MacBook Pro.

MacBook.

No way. PowerBook sounds way better. Give me back the PowerBook!

Hong Kong != PRC dammit

Published
by
spacehunt
on Wed, 26 Oct 2005
in English
. 0 Comments

That BitTorrent case sure did cause quite a bit of stir around technology sites. But what’s this about spending years in a PRC prison and flea markets around the corner?

Hong Kong is not China. They are under completely different jurisdictions. Is that clear mate? Criminals convicted in Hong Kong never serve their sentences in a PRC prison, just as criminals convicted in the UK don’t get sent to a French prison.

Furthermore, Hong Kong is a common law jurisdiction, and I haven’t seen any Americans grasp the significance of that. Americans. Ignorant as always.

(BTW has anyone seen the full text of the judgement yet? Case number is TMCC1286/2005.)

The Australian ePassport

Published
by
spacehunt
on Tue, 25 Oct 2005
in English
. 0 Comments

Australia launched their microchip-embedded ePassport today. Apart from the cheesy name (who still calls their stuff ‘eStuff’ nowadays?) and the price hike (AUD 19 more than before… wtf?), what caught my eye was that this will let them use automatic SmartGates for border control at airports, relying solely on face recognition. Is that really reliable? Hong Kong has these automatic gates too (e-Channel… damn, another e-Something), but they use fingerprints for that which is a much more mature technology. Face recognition, I don’t think so mate…

Flock

Published
by
spacehunt
on Fri, 21 Oct 2005
in English
. 0 Comments

Looks like the developer preview of Flock came out while I was on CX317. It’s certainly generating a lot of buzz. I’m playing with it right now, in fact this entry is posted using the built-in blog editor, where I can enter either raw HTML or use the rich-text editor; both are kept in sync on the fly. But annoyingly the rich-text editor keeps putting out superfluous <br /> tags. Some more impressions:

  • Much faster than Firefox 1.0, as Flock is based on Firefox 1.5.
  • Did not migrate my Firefox 1.0 settings. Others have noticed this too.
  • Nice tools to work with del.ico.us and Flickr, but I don’t use them both. Seems there will be a way to extend Flock to integrate with other photo galleries and bookmark sites in the future though.

Overall, pretty slick. I will have to play around with it a bit more though. Also, can all the features be added to Firefox via extensions?

Bad Behavior has blocked 536 access attempts in the last 7 days.