Re:The problem of rewriting/forking XFree
on
XFree86 Politics
·
· Score: 2, Insightful
Perhaps the problem here is that you aren't aware of how much of XFree has "been rewritten from srcatch" for XFree 4.0. Most of the DDI was rewritten. Even some of the device independent code was rewritten with the prime example being a complete replacement of cfb8, cfb16, cfb32, etc and mfb framebuffering code with a single framebuffer "fb". Why did you think XFree 4.0 took so long to be released. There were several 3.3.x releases while XFree 4.0 was being developed.
Frankly, there is little reason to consider a complete rewrite of XFree. The extensibility of X11 is such that almost any addition can be made (or removed) with little problem. Consider RandR, which addresses a lot of the issues people have had with XFree (resizing, etc). It is even intended that depth changing will be handled by this code eventually.
X11 is good at what it does, a network transparent graphics protocol. Throwing this out would either require you to be tied to a single machine or rewrite much of X11 in any case.
Niven definitively implied that the IQ of a Mob was inversely proportional to its size. This then implies bad things about/., or at least those that take part in the effect named after it:-)
The title of this book always makes me think of the Larry Niven concept of the flash crowd. He postulated if both communications and rapid transit existed (in his case teleportation), you'd get instant crowds around any geographic area when anything interesting was happening.
I remember a press release a few years back about a satellite that was left in a unusable orbit due to an upper stage failure of a proton rocket. It too was considered a write-off and the insurance company paid up.
However, Hughes, the company who built the satellite then figure out a way to use some of the station keeping fuel and gravity assist from the Moon to kick it into a geostationary orbit. The downside of this is a shorter operational lifetime as the station keeping fuel is what keeps the satellite at the equator and not wandering North-South on a 12 hour cycle.
Living in the suburb of Balmain in Sydney (Australia) a few years ago, the local prefix was indeed 555... I can remember the trouble I had trying to convince the person on the other end of the line when I bought some hardware on mail-order from the US, that this was "indeed my phone number." Of course the following question from me was "what do you need my phone number for anyway?"
I think you need to read the article in the Register. It states that RedHat were forced to take this measure due to the license that was placed on the patch, and then implied that it was Alan Cox who did this.
So if it is contrived, it was Alan Cox who did it, not RedHat. And it might also be argued that under the DMCA that pointing under flaws in other peoples software is illegal. Thus as Alan Cox isn't the owner of Linux, even though he is a major contributor, it is easy to argue that his license was a necessary restriction to prevent legal action under the DMCA
So you shouldn't see this as FUD, but rather the response of one developer to the perceived threat of legal action
Anyone who has worked in the microwave industry and has bought ferrite components, like isolators and circulators, will be able to guess that this isn't a low cost solution.
Higher gain antenna means directivity. So where exact is you base station relative to the phone? You you want to make your users turn thier heads to get the best reception?
So although as you say high gain antennas help you, keep them in the base stations.
God what horrible minds some software developers have.
This is not really on-topic, but I can see a horrible potential problem with the scheme of self-sabotaging software you're talking about. Two people working on the same files, without time synchronization between the machines (eg ntp). You could easily fall into a condition where the clock between the two machines was out. Even a few minutes out could cause this self-sabotage you're talking about!
A worse case might be dual-boot machine, where one OS stores the CMOS clock in UMT and the other in local time. We see this one all the time. So there you'd have potentially 12 hours of time error.
Frankly, I think software like this is dangereous to my data. I'd kind of feel obiliged to crack the software just to protect myself, rather than for any motives of piracy.
they could schedule some 2-year period (hard-coded on the DVD, if they want) during which the DVD would only be playable in a given place, but after this period, it could be played worldwide with *no* limitations...
How would you enforce this. The work around could be as simple as changing the date on your computer?
Have you read the story at the top of this page? The virus discussed uses the same scripting security hole in Outlook as a dozen other virus. Don't point to a particular virus and say that because this is an IIS bug and not an Outlook bug that my argument is specious.
Fact: This is no exploit for the PHP bug mentioned by the author to which I responded
My Opinion: This points to a strength in Open Source development in that it demonstrates a willing to address security issues in a rapid and timely manner. Something that I find lacking in Microsoft.
Frankly, I don't a shit how many idoit sys admins are still infected by CodeRed. My point was to point out that the original author threw out as an insult of the open source development model something that sane people would consider a strength.
You give a nice list of virii that tickle the same security hole in windows. And as you say the patch exist (turn off VB isn't it?)... I'm certain that there was an exploit of some form of this security hole before Microsoft had any fix in the market. Which one was it on your list?
My point was that the basic philosophy of Microsoft to security is that a security hole is not a problem until there is an exploit. Thus the previous authors comment about PHP, and the announcement of a security issue with no known exploit in the wild, in fact pointed to a strength in Open Source development rather than a weakness.
The difference is that there is no known exploit for this PHP security hole at the moment. The announcement is timely in that it allows sys admins to patch a POTENTIAL hole before they cause a problem.
When was the last time microsoft announced a security problem before there was a known exploit in the wild?
Hold on there before you throw the party. The wired article many the issue clear that the hardware manufacturers don't support government legislated control on content delivery. It however also made it clear that the hardware manufacturer would support the introduction of such control hardware as part of an industry based standard. To the user this is the same time. We're still screwed...
600 word letter? I'd love to still the exact text of what they wrote. Anyone seen a copy?
Which direction are radio astromoners looking. "Up" I hear you say. This puts a very large average attenuation on those pesky UWB transmitters.
What you say you're looking "sideways". Well I say don't those things Astronomies look at move
so that your telescope never points in the same direction if it is tracking something. So you might breifly be looking at a UWB transmitter straight on (though even that's very unlikely). However, you integrate over several hours of time don't you. So that brief bit of crappy data will be lost in your good data.
Frankly, I think the astronomy community whines about everybody else who uses the radio spectrum.
For me the people who will be the most effected by UWB aren't astronomers, and aren't GPS people either (due to the emission masks). The one who are likely to be most hurt are the satellite remote sensing people. Particularly the synthenitic aperture radar people. As opposed to astromoners, remote-sensing SAR looks down from a satellite to the Earth and could potentially see a huge number of UWB terminals. The combined interference of terminals will add significant noise to their data.
Its a shared resources, and please believe that the people who design communications systems are equally aware of this and try and take the measures necessary to avoid interference to others
You should note that GPS is not permitted as the only form of positioning in critical system. You don't see civil aviation that use only GPS without at least an inertial guidance system. There are good reason for this, as GPS can never be considered as a 100% reliable system that you'd want to trust your life to.
UWB will just lower this percentage reliably slightly.
In any case the UWB emission limit (in terms of EIRP) in the GPS band is at -65dBm (averaged over 1MHz I believe) which is -25dB under the current Part 15 limit for unintentional radiator. So you see the FCC took concerns about UWB's effects on GPS very very seriously.....
Drone Wars implies that both sides fight with
Drones and that there are limited or no casulaties. I don't think Afghanistan counts here. The Talibans didn't have that many drones, and the US drones certainly attacked live targets.
Your parallel with Sci-Fi themes is false.
There are typically many antennas on a satellite. You are probably talking to a relatively high gain antenna if you are only using a 6ft antenna. The command antenna has to work even when the satellite is in a spin our of control so that there is some hope of recovering it. Thus the command antenna on a satellite is typically omni-directional and thus you'll need higher gain on the ground (bigger antenna) to talk to it.
I see a lot of comments saying something like any cracker with an antenna could crack them. By stop and think about what you really need to done this. Telemetry, command and control and antennas on satellites have to be useable at ALL times, otherwise they are useless. Thus this function is typically seperated from the main antennas. If your shiny new satellite is spinning out of control in space due to a bad launch and its main high gain antenna isn't pointing toward the Earth, you want these things to work regardless. Thus the antenna for command and control of the satellite is omni-directional and thus low gain. As a consequence the gain of the antenna on the ground
needs to be larger and thus antenna itself is larger, typically 20m or more in diameter. Thus the equipement required to do this might be available to large government or private interests, its not available to your script kiddies. So if your a running a micro-satellite
thats main reason is scientific research, and you want to share the scientific data in any case, why bother securing it against the few malevolant large organisations that probably 1) have no interest in your system, and 2) would cause a major international scandal if they damaged your system in anyway due to their efforts.
Shared use of spectrum is already happening. Where did you think the spectrum for those 802.11a systems in the 5 to 6GHz band comes from. These same bands are already occupied by C-band satellite services....
The key here is that the secondary service is in no way allowed to interfere with the primary service. Hence, there are strict limitations of the way these bands are used. I.E. 23 dBm maximum transmit power for 802.11a in the 5.18 to 5.29GHz band.
David
Before you try adding directive antennas to
you 802.11 box, I'd suggest checking if what
you are trying to do is legal.
The idea of adding a directive antenna to a
system to get most gain and thus a longer transmit
distance is sound. The problem is that you can
also interfer with anyone else system who happens
to fall along the axis of the directive antenna.
This is why most countries regulate these systems
on their EIRP, or effective radiated power and
not their actual power. The difference between
EIRP and power is that EIRP inlcudes the effect
of the gain of the antenna. Thus if you use a
more directive antenna than the manufacturer
installed, you are almost certain to be illegal.
This is not point-to-point systems. They are all design with indoor propagation in mind. The range depends much on the envirnoment in which the system is used (i.e American offices don't have the same construction as Japanese ones), on the speed you are trying to use, the transmit power used and on the error rate you are willing to accept. The standard acceptable error rate with these 5GHz systems is 1 in 10 packets lost. This represents a bit error rate much smaller than this (1e-3 approximately).
At the lowest transmit rate of 6Mb/s with this system you should be a cell size quite large
(50 to 100m). But at the maximum rate of 54Mb/s
that cell size will drop to 10 or 20m. These
numbers are for a standard office envirnoment,
with a high transmit power.
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Perhaps the problem here is that you aren't aware of how much of XFree has "been rewritten from srcatch" for XFree 4.0. Most of the DDI was rewritten. Even some of the device independent code was rewritten with the prime example being a complete replacement of cfb8, cfb16, cfb32, etc and mfb framebuffering code with a single framebuffer "fb". Why did you think XFree 4.0 took so long to be released. There were several 3.3.x releases while XFree 4.0 was being developed.
Frankly, there is little reason to consider a complete rewrite of XFree. The extensibility of X11 is such that almost any addition can be made
(or removed) with little problem. Consider RandR,
which addresses a lot of the issues people have had with XFree (resizing, etc). It is even intended that depth changing will be handled by this code eventually.
X11 is good at what it does, a network transparent graphics protocol. Throwing this out would either require you to be tied to a single machine or rewrite much of X11 in any case.
D.
D.
Cheers
D.
Has the author acknowledged Larry Niven??
Regards David
However, Hughes, the company who built the satellite then figure out a way to use some of the station keeping fuel and gravity assist from the Moon to kick it into a geostationary orbit. The downside of this is a shorter operational lifetime as the station keeping fuel is what keeps the satellite at the equator and not wandering North-South on a 12 hour cycle.
A reference to this can be found on the Satellite Toolkit (STK) website http://www.stk.com/press/display.cfm?id=24
D.
D.
Living in the suburb of Balmain in Sydney (Australia) a few years ago, the local prefix was indeed 555... I can remember the trouble I had trying to convince the person on the other end of the line when I bought some hardware on mail-order from the US, that this was "indeed my phone number." Of course the following question from me was "what do you need my phone number for anyway?"
Cheers
D.
So if it is contrived, it was Alan Cox who did it, not RedHat. And it might also be argued that under the DMCA that pointing under flaws in other peoples software is illegal. Thus as Alan Cox isn't the owner of Linux, even though he is a major contributor, it is easy to argue that his license was a necessary restriction to prevent legal action under the DMCA
So you shouldn't see this as FUD, but rather the response of one developer to the perceived threat of legal action
D.
Anyone who has worked in the microwave industry and has bought ferrite components, like isolators and circulators, will be able to guess that this isn't a low cost solution.
D.
Fine. Then lets get rid of the GOVERNMENT supportted intellectual property laws.
D.
So although as you say high gain antennas help you, keep them in the base stations.
D.
This is not really on-topic, but I can see a horrible potential problem with the scheme of self-sabotaging software you're talking about. Two people working on the same files, without time synchronization between the machines (eg ntp). You could easily fall into a condition where the clock between the two machines was out. Even a few minutes out could cause this self-sabotage you're talking about!
A worse case might be dual-boot machine, where one OS stores the CMOS clock in UMT and the other in local time. We see this one all the time. So there you'd have potentially 12 hours of time error.
Frankly, I think software like this is dangereous to my data. I'd kind of feel obiliged to crack the software just to protect myself, rather than for any motives of piracy.
D.
they could schedule some 2-year period (hard-coded on the DVD, if they want) during which the DVD would only be playable in a given place, but after this period, it could be played worldwide with *no* limitations...
How would you enforce this. The work around could be as simple as changing the date on your computer?
D.
Fact: This is no exploit for the PHP bug mentioned by the author to which I responded
My Opinion: This points to a strength in Open Source development in that it demonstrates a willing to address security issues in a rapid and timely manner. Something that I find lacking in Microsoft.
Frankly, I don't a shit how many idoit sys admins are still infected by CodeRed. My point was to point out that the original author threw out as an insult of the open source development model something that sane people would consider a strength.
D.
My point was that the basic philosophy of Microsoft to security is that a security hole is not a problem until there is an exploit. Thus the previous authors comment about PHP, and the announcement of a security issue with no known exploit in the wild, in fact pointed to a strength in Open Source development rather than a weakness.
D.
When was the last time microsoft announced a security problem before there was a known exploit in the wild?
D.
Hold on there before you throw the party. The wired article many the issue clear that the hardware manufacturers don't support government legislated control on content delivery. It however also made it clear that the hardware manufacturer would support the introduction of such control hardware as part of an industry based standard. To the user this is the same time.
We're still screwed...
600 word letter? I'd love to still the exact text of what they wrote. Anyone seen a copy?
D.
What you say you're looking "sideways". Well I say don't those things Astronomies look at move
so that your telescope never points in the same direction if it is tracking something. So you might breifly be looking at a UWB transmitter straight on (though even that's very unlikely). However, you integrate over several hours of time don't you. So that brief bit of crappy data will be lost in your good data.
Frankly, I think the astronomy community whines about everybody else who uses the radio spectrum.
For me the people who will be the most effected by UWB aren't astronomers, and aren't GPS people either (due to the emission masks). The one who are likely to be most hurt are the satellite remote sensing people. Particularly the synthenitic aperture radar people. As opposed to astromoners, remote-sensing SAR looks down from a satellite to the Earth and could potentially see a huge number of UWB terminals. The combined interference of terminals will add significant noise to their data.
Its a shared resources, and please believe that the people who design communications systems are equally aware of this and try and take the measures necessary to avoid interference to others
D.
UWB will just lower this percentage reliably slightly.
In any case the UWB emission limit (in terms of EIRP) in the GPS band is at -65dBm (averaged over 1MHz I believe) which is -25dB under the current Part 15 limit for unintentional radiator. So you see the FCC took concerns about UWB's effects on GPS very very seriously.....
D.
Drone Wars implies that both sides fight with
Drones and that there are limited or no casulaties. I don't think Afghanistan counts here. The Talibans didn't have that many drones, and the US drones certainly attacked live targets.
Your parallel with Sci-Fi themes is false.
D.
There are typically many antennas on a satellite. You are probably talking to a relatively high gain antenna if you are only using a 6ft antenna. The command antenna has to work even when the satellite is in a spin our of control so that there is some hope of recovering it. Thus the command antenna on a satellite is typically omni-directional and thus you'll need higher gain on the ground (bigger antenna) to talk to it.
D.
I see a lot of comments saying something like any cracker with an antenna could crack them. By stop and think about what you really need to done this. Telemetry, command and control and antennas on satellites have to be useable at ALL times, otherwise they are useless. Thus this function is typically seperated from the main antennas. If your shiny new satellite is spinning out of control in space due to a bad launch and its main high gain antenna isn't pointing toward the Earth, you want these things to work regardless. Thus the antenna for command and control of the satellite is omni-directional and thus low gain. As a consequence the gain of the antenna on the ground
needs to be larger and thus antenna itself is larger, typically 20m or more in diameter. Thus the equipement required to do this might be available to large government or private interests, its not available to your script kiddies. So if your a running a micro-satellite
thats main reason is scientific research, and you want to share the scientific data in any case, why bother securing it against the few malevolant large organisations that probably 1) have no interest in your system, and 2) would cause a major international scandal if they damaged your system in anyway due to their efforts.
Cheers
David
The key here is that the secondary service is in no way allowed to interfere with the primary service. Hence, there are strict limitations of the way these bands are used. I.E. 23 dBm maximum transmit power for 802.11a in the 5.18 to 5.29GHz band. David
The idea of adding a directive antenna to a system to get most gain and thus a longer transmit distance is sound. The problem is that you can also interfer with anyone else system who happens to fall along the axis of the directive antenna. This is why most countries regulate these systems on their EIRP, or effective radiated power and not their actual power. The difference between EIRP and power is that EIRP inlcudes the effect of the gain of the antenna. Thus if you use a more directive antenna than the manufacturer installed, you are almost certain to be illegal.
D.
At the lowest transmit rate of 6Mb/s with this system you should be a cell size quite large (50 to 100m). But at the maximum rate of 54Mb/s that cell size will drop to 10 or 20m. These numbers are for a standard office envirnoment, with a high transmit power.