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• * Re: [Bcm43xx-dev] [Fwd: State of the Union: Wireless]
         [not found] <1136541243.4037.18.camel@localhost>
  @ 2006-01-06 11:00 ` Michael Buesch
    2006-01-06 11:38   ` Marcel Holtmann
    2006-01-06 17:02   ` Ben Greear
    0 siblings, 2 replies; 14+ messages in thread
  From: Michael Buesch @ 2006-01-06 11:00 UTC (permalink / raw)
    To: jgarzik; +Cc: bcm43xx-dev, netdev, linux-kernel
  
  [-- Attachment #1: Type: text/plain, Size: 4829 bytes --]
  
  > > * We really have no wireless maintainer.  I'm just the defacto guy,
  > >   with no interest in the job.  The ideal maintainer knows 802.11 well,
  > >   uses git, and isn't an asshole with no taste.  I'm just the guy who
  > >   wants to make sure the net driver portion doesn't turn out to be a
  > >   stinker (read: review and pass up the chain).
  
  That problem is easiest to solve. ;)
  
  > > * Wireless management, in particular the wireless kernel<->user
  > >   interface, needs some thinking.  Wireless Extensions (WE) isn't
  > >   cutting it, but I haven't seen any netlink work yet (or some
  > >   other interface).  Whatever the userspace interface is, it will be
  > >   basically carved in stone for years (unlike kernel APIs), so this
  > >   needs a lot more thought than people have been giving it.
  
  We did some brainstorming about this yesterday evening on the bcm
  irc channel. I think we all agreed on dropping WE.
  So, now we asked: How would a sane UI look like. We had a few points:
  * The interface needs to support some kind of "master" interface to
  configure the hardware, 80211 parameters and
  to actually configure and setup the
  * Virtual interfaces.
  Data is transferred only though the virtual interfaces, which could
  be an AP interface, a STA interface in INFRA or Ad-Hoc mode, etc... .
  Configuration is done though the master interface.
  
  How would the virtual interfaces look like? That is quite easy to answer.
  They are net_devices, as they transfer data.
  They should probaly _not_ be on top of the ethernet, as 80211 does not
  have very much in common with ethernet. Basically they share the same
  MAC address format. Does someone have another thing, which he thinks
  is shared?
  How would the master interface look like? A somewhat unusual idea came
  up. Using a device node in /dev. So every wireless card in the system
  would have a node in /dev associated (/dev/wlan0 for example).
  A node for the master device would be ok, because no data is transferred
  through it. It is only a configuration interface.
  So you would tell the, yet-to-be-written userspace tool wconfig (or something
  like that) "I need a STA in INFRA mode and want to drive it on the
  wlan0 card". So wconfig goes and write()s some data to /dev/wlan0
  telling the 80211 code to setup a virtual net_device for the driver
  associated to /dev/wlan0.
  The virtual interface is then configured though /dev/wlan0 using write()
  (no ugly ioctl anymore, you see...). Config data like TX rate,
  current essid,.... basically everything + xyz which is done by WE today,
  is written to /dev/wlan0.
  This config data is entirely cached in the 80211 code for the /dev/wlan0
  instance. This is important, to have the data persistent throughout
  suspend/resume cycles, if up/down cycles.
  After configuring, a virtual net_device (let's call it wlan0) exists,
  which can be brought up by ifconfig and data can be transferred though
  it as usual.
  
  This whole concept is derived from how dscape does the stuff.
  With a major exception, that a device node instead of a net_device
  is used for the master device. With the effect of getting rid of the
  ugly WE ioctl stuff.
  
  > > * Long term, wireless should go from being a library of common code to a
  > >   "real" wireless stack, as shown in the template developed by David Miller:
  > >   http://kernel.org/pub/linux/kernel/people/jgarzik/patchkits/2.6/davem-p80211.tar.bz2
  > >   Zhu Yi @ Intel and Vladmir @ somewhere both independently did some
  > >   work in this area.
  
  This looks very interresting and in fact is part of our thoughts I
  explained above.
  
  > > * I prefer GPL-only code.  Dual licensing has proven in practice to
  > >   be a logistical nightmare that concentrates power in the hands of
  > >   a few.  Dual licensing, BSD licensing works for some, but GPL-only
  > >   code is quite simply the least amount of flamewars, headaches
  > >   and worry.  IOW, the P.I.T.A. level of GPL-only code is lowest.
  
  I personally prefer EXPORT_SYMBOL_GPL().
  But that's only my opinion and that does not really matter. ;)
  
  > > Dual licensed code gives kernel hackers yet more legal crapola to
  > > worry about, which is never a good thing.
  
  I don't see a point in dual licensing it.
  The only benefit would be to allow BSD people to take the code.
  Honestly, I really don't see this happening, anyway. ;)
  They have net80211.
  
  > > Patches welcome from all motivated, clueful parties.  Jiri Benc has a
  > > long series of patches that looks nice.  Johannes Berg has done some
  > > work on the ieee80211 softmac stuff and hw WEP.  But maybe DeviceScape
  > > is what people like now.
  
  Well, "like" is a strong word. I personally would say "It is better than
  all currently existing solutions, if some final polishing is done to dscape."
  
  -- 
  Greetings Michael.
  
  [-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]
  
  ^ permalink raw reply	[flat|nested] 14+ messages in thread

• • * Re: [Bcm43xx-dev] [Fwd: State of the Union: Wireless]
      2006-01-06 11:00 ` [Bcm43xx-dev] [Fwd: State of the Union: Wireless] Michael Buesch
    @ 2006-01-06 11:38   ` Marcel Holtmann
      2006-01-06 11:45     ` Michael Buesch
      2006-01-06 17:02   ` Ben Greear
      1 sibling, 1 reply; 14+ messages in thread
    From: Marcel Holtmann @ 2006-01-06 11:38 UTC (permalink / raw)
      To: Michael Buesch; +Cc: jgarzik, bcm43xx-dev, netdev, linux-kernel
    
    Hi Michael,
    
    > How would the virtual interfaces look like? That is quite easy to answer.
    > They are net_devices, as they transfer data.
    > They should probaly _not_ be on top of the ethernet, as 80211 does not
    > have very much in common with ethernet. Basically they share the same
    > MAC address format. Does someone have another thing, which he thinks
    > is shared?
    > How would the master interface look like? A somewhat unusual idea came
    > up. Using a device node in /dev. So every wireless card in the system
    > would have a node in /dev associated (/dev/wlan0 for example).
    > A node for the master device would be ok, because no data is transferred
    > through it. It is only a configuration interface.
    > So you would tell the, yet-to-be-written userspace tool wconfig (or something
    > like that) "I need a STA in INFRA mode and want to drive it on the
    > wlan0 card". So wconfig goes and write()s some data to /dev/wlan0
    > telling the 80211 code to setup a virtual net_device for the driver
    > associated to /dev/wlan0.
    > The virtual interface is then configured though /dev/wlan0 using write()
    > (no ugly ioctl anymore, you see...). Config data like TX rate,
    > current essid,.... basically everything + xyz which is done by WE today,
    > is written to /dev/wlan0.
    > This config data is entirely cached in the 80211 code for the /dev/wlan0
    > instance. This is important, to have the data persistent throughout
    > suspend/resume cycles, if up/down cycles.
    > After configuring, a virtual net_device (let's call it wlan0) exists,
    > which can be brought up by ifconfig and data can be transferred though
    > it as usual.
    
    what is wrong with using netlink and/or sysfs for it? I don't see the
    advantage of defining another /dev something interface.
    
    Regards
    
    Marcel
    
    ^ permalink raw reply	[flat|nested] 14+ messages in thread

  • • * Re: [Fwd: State of the Union: Wireless]
        2006-01-06 11:38   ` Marcel Holtmann
      @ 2006-01-06 11:45     ` Michael Buesch
        2006-01-06 12:10       ` [Bcm43xx-dev] " Marcel Holtmann
        2006-01-06 16:12       ` Feyd
        0 siblings, 2 replies; 14+ messages in thread
      From: Michael Buesch @ 2006-01-06 11:45 UTC (permalink / raw)
        To: Marcel Holtmann
        Cc: jgarzik-e+AXbWqSrlAAvxtiuMwx3w,
      	bcm43xx-dev-0fE9KPoRgkgATYTw5x5z8w, netdev-u79uwXL29TY76Z2rM5mHXA,
      	linux-kernel-u79uwXL29TY76Z2rM5mHXA
      
      [-- Attachment #1: Type: text/plain, Size: 2712 bytes --]
      
      On Friday 06 January 2006 12:38, you wrote:
      > Hi Michael,
      > 
      > > How would the virtual interfaces look like? That is quite easy to answer.
      > > They are net_devices, as they transfer data.
      > > They should probaly _not_ be on top of the ethernet, as 80211 does not
      > > have very much in common with ethernet. Basically they share the same
      > > MAC address format. Does someone have another thing, which he thinks
      > > is shared?
      > > How would the master interface look like? A somewhat unusual idea came
      > > up. Using a device node in /dev. So every wireless card in the system
      > > would have a node in /dev associated (/dev/wlan0 for example).
      > > A node for the master device would be ok, because no data is transferred
      > > through it. It is only a configuration interface.
      > > So you would tell the, yet-to-be-written userspace tool wconfig (or something
      > > like that) "I need a STA in INFRA mode and want to drive it on the
      > > wlan0 card". So wconfig goes and write()s some data to /dev/wlan0
      > > telling the 80211 code to setup a virtual net_device for the driver
      > > associated to /dev/wlan0.
      > > The virtual interface is then configured though /dev/wlan0 using write()
      > > (no ugly ioctl anymore, you see...). Config data like TX rate,
      > > current essid,.... basically everything + xyz which is done by WE today,
      > > is written to /dev/wlan0.
      > > This config data is entirely cached in the 80211 code for the /dev/wlan0
      > > instance. This is important, to have the data persistent throughout
      > > suspend/resume cycles, if up/down cycles.
      > > After configuring, a virtual net_device (let's call it wlan0) exists,
      > > which can be brought up by ifconfig and data can be transferred though
      > > it as usual.
      > 
      > what is wrong with using netlink and/or sysfs for it? I don't see the
      > advantage of defining another /dev something interface.
      
      Nothing is wrong with that.
      "brainstorming" was the most dominant word in the whole text. ;)
      I just personally liked the idea of having a device node in /dev for
      every existing hardware wlan card. Like we have device nodes for
      other real hardware, too. It felt like a bit of a "unix way" to do
      this to me. I don't say this is the way to go.
      If a netlink socket is used (which is possible, for sure), we stay with
      the old way of having no device node in /dev for networking devices.
      That is ok. But that is really only an implementation detail (and for sure
      a matter of taste).
      The _real_ main point I wanted to make was to _not_ use a net_device for
      the master device. What else should be used for master device, let it
      be a device node or a netlink socket, is rather unimportant at
      this stage.
      
      -- 
      Greetings Michael.
      
      [-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]
      
      ^ permalink raw reply	[flat|nested] 14+ messages in thread

    • • * Re: [Bcm43xx-dev] [Fwd: State of the Union: Wireless]
          2006-01-06 11:45     ` Michael Buesch
        @ 2006-01-06 12:10       ` Marcel Holtmann
          2006-01-06 12:46         ` Patrick McHardy
          2006-01-06 16:12       ` Feyd
          1 sibling, 1 reply; 14+ messages in thread
        From: Marcel Holtmann @ 2006-01-06 12:10 UTC (permalink / raw)
          To: Michael Buesch; +Cc: jgarzik, bcm43xx-dev, netdev, linux-kernel
        
        Hi Michael,
        
        > > > How would the virtual interfaces look like? That is quite easy to answer.
        > > > They are net_devices, as they transfer data.
        > > > They should probaly _not_ be on top of the ethernet, as 80211 does not
        > > > have very much in common with ethernet. Basically they share the same
        > > > MAC address format. Does someone have another thing, which he thinks
        > > > is shared?
        > > > How would the master interface look like? A somewhat unusual idea came
        > > > up. Using a device node in /dev. So every wireless card in the system
        > > > would have a node in /dev associated (/dev/wlan0 for example).
        > > > A node for the master device would be ok, because no data is transferred
        > > > through it. It is only a configuration interface.
        > > > So you would tell the, yet-to-be-written userspace tool wconfig (or something
        > > > like that) "I need a STA in INFRA mode and want to drive it on the
        > > > wlan0 card". So wconfig goes and write()s some data to /dev/wlan0
        > > > telling the 80211 code to setup a virtual net_device for the driver
        > > > associated to /dev/wlan0.
        > > > The virtual interface is then configured though /dev/wlan0 using write()
        > > > (no ugly ioctl anymore, you see...). Config data like TX rate,
        > > > current essid,.... basically everything + xyz which is done by WE today,
        > > > is written to /dev/wlan0.
        > > > This config data is entirely cached in the 80211 code for the /dev/wlan0
        > > > instance. This is important, to have the data persistent throughout
        > > > suspend/resume cycles, if up/down cycles.
        > > > After configuring, a virtual net_device (let's call it wlan0) exists,
        > > > which can be brought up by ifconfig and data can be transferred though
        > > > it as usual.
        > > 
        > > what is wrong with using netlink and/or sysfs for it? I don't see the
        > > advantage of defining another /dev something interface.
        > 
        > Nothing is wrong with that.
        > "brainstorming" was the most dominant word in the whole text. ;)
        
        so I might got the wrong impression, because it seemed you put a lot of
        thinking into the /dev/wlanX stuff without even considering netlink or
        something else.
        
        > I just personally liked the idea of having a device node in /dev for
        > every existing hardware wlan card. Like we have device nodes for
        > other real hardware, too. It felt like a bit of a "unix way" to do
        > this to me. I don't say this is the way to go.
        > If a netlink socket is used (which is possible, for sure), we stay with
        > the old way of having no device node in /dev for networking devices.
        > That is ok. But that is really only an implementation detail (and for sure
        > a matter of taste).
        
        At the OLS last year, I think the consensus was to use netlink for all
        configuration task. However this was mainly driven by Harald Welte and
        he might be able to talk about the pros and cons of netlink versus a
        character device.
        
        > The _real_ main point I wanted to make was to _not_ use a net_device for
        > the master device. What else should be used for master device, let it
        > be a device node or a netlink socket, is rather unimportant at
        > this stage.
        
        I am all for it, because I don't like dummy Ethernet devices that are
        only used for configuration. I am still not happy that IrDA uses irda0
        to get somekind of packet management etc. instead of implementing a real
        suitable hardware abstraction.
        
        Regards
        
        Marcel
        
        ^ permalink raw reply	[flat|nested] 14+ messages in thread

      • • * Re: [Bcm43xx-dev] [Fwd: State of the Union: Wireless]
            2006-01-06 12:10       ` [Bcm43xx-dev] " Marcel Holtmann
          @ 2006-01-06 12:46         ` Patrick McHardy
            2006-01-06 18:23           ` Stephen Hemminger
                                       ` (2 more replies)
            0 siblings, 3 replies; 14+ messages in thread
          From: Patrick McHardy @ 2006-01-06 12:46 UTC (permalink / raw)
            To: Marcel Holtmann
            Cc: Michael Buesch, jgarzik, bcm43xx-dev, netdev, linux-kernel
          
          Marcel Holtmann wrote:
          
          >>I just personally liked the idea of having a device node in /dev for
          >>every existing hardware wlan card. Like we have device nodes for
          >>other real hardware, too. It felt like a bit of a "unix way" to do
          >>this to me. I don't say this is the way to go.
          >>If a netlink socket is used (which is possible, for sure), we stay with
          >>the old way of having no device node in /dev for networking devices.
          >>That is ok. But that is really only an implementation detail (and for sure
          >>a matter of taste).
          > 
          > 
          > At the OLS last year, I think the consensus was to use netlink for all
          > configuration task. However this was mainly driven by Harald Welte and
          > he might be able to talk about the pros and cons of netlink versus a
          > character device.
          
          I think the main advantages of netlink over a character device is its
          flexible format, which is easily extendable, and multicast capability,
          which can be used to broadcast events and configuration changes. Its
          also good to have all the net stuff accessible in a uniform way.
          
          ^ permalink raw reply	[flat|nested] 14+ messages in thread

        • • * Re: [Bcm43xx-dev] [Fwd: State of the Union: Wireless]
              2006-01-06 12:46         ` Patrick McHardy
            @ 2006-01-06 18:23           ` Stephen Hemminger
              2006-01-06 22:16           ` David Lang
              2006-01-12 14:20           ` Harald Welte
              2 siblings, 0 replies; 14+ messages in thread
            From: Stephen Hemminger @ 2006-01-06 18:23 UTC (permalink / raw)
              To: Patrick McHardy
              Cc: Marcel Holtmann, Michael Buesch, jgarzik, bcm43xx-dev, netdev,
            	linux-kernel
            
            On Fri, 06 Jan 2006 13:46:15 +0100
            Patrick McHardy <kaber@trash•net> wrote:
            
            > Marcel Holtmann wrote:
            > 
            > >>I just personally liked the idea of having a device node in /dev for
            > >>every existing hardware wlan card. Like we have device nodes for
            > >>other real hardware, too. It felt like a bit of a "unix way" to do
            > >>this to me. I don't say this is the way to go.
            > >>If a netlink socket is used (which is possible, for sure), we stay with
            > >>the old way of having no device node in /dev for networking devices.
            > >>That is ok. But that is really only an implementation detail (and for sure
            > >>a matter of taste).
            > > 
            > > 
            > > At the OLS last year, I think the consensus was to use netlink for all
            > > configuration task. However this was mainly driven by Harald Welte and
            > > he might be able to talk about the pros and cons of netlink versus a
            > > character device.
            > 
            > I think the main advantages of netlink over a character device is its
            > flexible format, which is easily extendable, and multicast capability,
            > which can be used to broadcast events and configuration changes. Its
            > also good to have all the net stuff accessible in a uniform way.
            
            Also netlink doesn't have the naming issues that /dev node would.
            
            -- 
            Stephen Hemminger <shemminger@osdl•org>
            OSDL http://developer.osdl.org/~shemminger
            
            ^ permalink raw reply	[flat|nested] 14+ messages in thread

          • * Re: [Bcm43xx-dev] [Fwd: State of the Union: Wireless]
              2006-01-06 12:46         ` Patrick McHardy
              2006-01-06 18:23           ` Stephen Hemminger
            @ 2006-01-06 22:16           ` David Lang
              2006-01-06 22:18             ` David S. Miller
              2006-01-06 22:22             ` Patrick McHardy
              2006-01-12 14:20           ` Harald Welte
              2 siblings, 2 replies; 14+ messages in thread
            From: David Lang @ 2006-01-06 22:16 UTC (permalink / raw)
              To: Patrick McHardy
              Cc: Marcel Holtmann, Michael Buesch, jgarzik, bcm43xx-dev, netdev,
            	linux-kernel
            
            On Fri, 6 Jan 2006, Patrick McHardy wrote:
            
            > Marcel Holtmann wrote:
            >
            >>> I just personally liked the idea of having a device node in /dev for
            >>> every existing hardware wlan card. Like we have device nodes for
            >>> other real hardware, too. It felt like a bit of a "unix way" to do
            >>> this to me. I don't say this is the way to go.
            >>> If a netlink socket is used (which is possible, for sure), we stay with
            >>> the old way of having no device node in /dev for networking devices.
            >>> That is ok. But that is really only an implementation detail (and for sure
            >>> a matter of taste).
            >> 
            >> 
            >> At the OLS last year, I think the consensus was to use netlink for all
            >> configuration task. However this was mainly driven by Harald Welte and
            >> he might be able to talk about the pros and cons of netlink versus a
            >> character device.
            >
            > I think the main advantages of netlink over a character device is its
            > flexible format, which is easily extendable, and multicast capability,
            > which can be used to broadcast events and configuration changes. Its
            > also good to have all the net stuff accessible in a uniform way.
            
            character devices are far easier to script. this really sounds like the 
            type of configuration stuff that sysfs was designed for. can we avoid yet 
            another configuration tool that's required?
            
            David Lang
            
            -- 
            There are two ways of constructing a software design. One way is to make it so simple that there are obviously no deficiencies. And the other way is to make it so complicated that there are no obvious deficiencies.
              -- C.A.R. Hoare
            
            ^ permalink raw reply	[flat|nested] 14+ messages in thread

          • • * Re: [Bcm43xx-dev] [Fwd: State of the Union: Wireless]
                2006-01-06 22:16           ` David Lang
              @ 2006-01-06 22:18             ` David S. Miller
                2006-01-09 18:24               ` Ingo Oeser
                2006-01-06 22:22             ` Patrick McHardy
                1 sibling, 1 reply; 14+ messages in thread
              From: David S. Miller @ 2006-01-06 22:18 UTC (permalink / raw)
                To: dlang; +Cc: kaber, marcel, mbuesch, jgarzik, bcm43xx-dev, netdev,
              	linux-kernel
              
              From: David Lang <dlang@digitalinsight•com>
              Date: Fri, 6 Jan 2006 14:16:17 -0800 (PST)
              
              > character devices are far easier to script. this really sounds like the 
              > type of configuration stuff that sysfs was designed for. can we avoid yet 
              > another configuration tool that's required?
              
              netlink is being recommended exactly because it can result
              in only needing one tool for everything
              
              ^ permalink raw reply	[flat|nested] 14+ messages in thread

            • • * Re: [Bcm43xx-dev] [Fwd: State of the Union: Wireless]
                  2006-01-06 22:18             ` David S. Miller
                @ 2006-01-09 18:24               ` Ingo Oeser
                  0 siblings, 0 replies; 14+ messages in thread
                From: Ingo Oeser @ 2006-01-09 18:24 UTC (permalink / raw)
                  To: David S. Miller
                  Cc: dlang, kaber, marcel, mbuesch, jgarzik, bcm43xx-dev, netdev,
                	linux-kernel
                
                David S. Miller wrote:
                > From: David Lang <dlang@digitalinsight•com>
                > Date: Fri, 6 Jan 2006 14:16:17 -0800 (PST)
                > 
                > > character devices are far easier to script. this really sounds like the 
                > > type of configuration stuff that sysfs was designed for. can we avoid yet 
                > > another configuration tool that's required?
                > 
                > netlink is being recommended exactly because it can result
                > in only needing one tool for everything
                
                Yes, iproute2 rocks!
                
                I recently discovered that it can do "xfrm" stuff and was amazed to
                see that the developer(s) had a big clue about what we like to
                see (and what is human readable), if we type "ip xfrm state" 
                and "ip xfrm policy" as opposed to "setkey -D" and "setkey -PD".
                
                So I can only hope that netlink and iproute will be chosen as a way
                to represent it to the user, just because of the clueful developers of
                iproute2.
                
                
                Regards
                
                Ingo Oeser
                
                ^ permalink raw reply	[flat|nested] 14+ messages in thread

            • * Re: [Bcm43xx-dev] [Fwd: State of the Union: Wireless]
                2006-01-06 22:16           ` David Lang
                2006-01-06 22:18             ` David S. Miller
              @ 2006-01-06 22:22             ` Patrick McHardy
                1 sibling, 0 replies; 14+ messages in thread
              From: Patrick McHardy @ 2006-01-06 22:22 UTC (permalink / raw)
                To: David Lang
                Cc: Marcel Holtmann, Michael Buesch, jgarzik, bcm43xx-dev, netdev,
              	linux-kernel
              
              David Lang wrote:
              > On Fri, 6 Jan 2006, Patrick McHardy wrote:
              > 
              >> I think the main advantages of netlink over a character device is its
              >> flexible format, which is easily extendable, and multicast capability,
              >> which can be used to broadcast events and configuration changes. Its
              >> also good to have all the net stuff accessible in a uniform way.
              > 
              > 
              > character devices are far easier to script. this really sounds like the 
              > type of configuration stuff that sysfs was designed for. can we avoid 
              > yet another configuration tool that's required?
              
              I think its not just configuration but also event handling
              for associating, link layer authentication, ..., which is
              not something handled by scripts but by some daemon. It might
              also want to set up routes or ip addresses which is done using
              netlink anyway.
              
              ^ permalink raw reply	[flat|nested] 14+ messages in thread

          • * Re: [Bcm43xx-dev] [Fwd: State of the Union: Wireless]
              2006-01-06 12:46         ` Patrick McHardy
              2006-01-06 18:23           ` Stephen Hemminger
              2006-01-06 22:16           ` David Lang
            @ 2006-01-12 14:20           ` Harald Welte
              2 siblings, 0 replies; 14+ messages in thread
            From: Harald Welte @ 2006-01-12 14:20 UTC (permalink / raw)
              To: Patrick McHardy
              Cc: Marcel Holtmann, Michael Buesch, jgarzik, bcm43xx-dev, netdev,
            	linux-kernel
            
            [-- Attachment #1: Type: text/plain, Size: 2061 bytes --]
            
            On Fri, Jan 06, 2006 at 01:46:15PM +0100, Patrick McHardy wrote:
            > Marcel Holtmann wrote:
            > 
            > >>I just personally liked the idea of having a device node in /dev for
            > >>every existing hardware wlan card. Like we have device nodes for
            > >>other real hardware, too. It felt like a bit of a "unix way" to do
            > >>this to me. I don't say this is the way to go.
            > >>If a netlink socket is used (which is possible, for sure), we stay with
            > >>the old way of having no device node in /dev for networking devices.
            > >>That is ok. But that is really only an implementation detail (and for sure
            > >>a matter of taste).
            > >At the OLS last year, I think the consensus was to use netlink for all
            > >configuration task. However this was mainly driven by Harald Welte and
            > >he might be able to talk about the pros and cons of netlink versus a
            > >character device.
            > 
            > I think the main advantages of netlink over a character device is its
            > flexible format, which is easily extendable, and multicast capability,
            
            Especially the multicast capability is _extrmely_ handy, since you
            basically can have all sorts of dock-applets or monitoring applications
            that don't need to rely on polling device status but instead get
            multicast notifications of configuration changes.
            
            Also, as a theoretical option, you could implement parts of the wireless
            subsystem outside of the kernel - esp. for the more extensive
            authentication/keying/rekeying functions.
            
            A wireless configuration program would just speak netlink to a
            particular netlink multicast group.  Whether or not the receiving
            functional entity is implemented in the kernel or in a wireless daemon
            in userspace could be completely transparent, as long as the protocol is
            the same.
            
            -- 
            - Harald Welte <laforge@gnumonks•org>          	        http://gnumonks.org/
            ============================================================================
            "Privacy in residential applications is a desirable marketing option."
                                                              (ETSI EN 300 175-7 Ch. A6)
            
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            ^ permalink raw reply	[flat|nested] 14+ messages in thread

      • * Re: [Bcm43xx-dev] [Fwd: State of the Union: Wireless]
          2006-01-06 11:45     ` Michael Buesch
          2006-01-06 12:10       ` [Bcm43xx-dev] " Marcel Holtmann
        @ 2006-01-06 16:12       ` Feyd
          2006-01-06 16:25         ` Johannes Berg
          1 sibling, 1 reply; 14+ messages in thread
        From: Feyd @ 2006-01-06 16:12 UTC (permalink / raw)
          To: Michael Buesch
          Cc: Marcel Holtmann, jgarzik, bcm43xx-dev, netdev, linux-kernel
        
        Michael Buesch wrote:
        > The _real_ main point I wanted to make was to _not_ use a net_device for
        > the master device. What else should be used for master device, let it
        > be a device node or a netlink socket, is rather unimportant at
        > this stage.
        
        If the only purpose of the master device was configuration, then it
        would be beter to use something other then a net_device, but you may
        want to send/receive raw 802.11 packets from userspace, most logicaly
        over a master interface.
        
        Feyd
        
        ^ permalink raw reply	[flat|nested] 14+ messages in thread

      • • * Re: [Bcm43xx-dev] [Fwd: State of the Union: Wireless]
            2006-01-06 16:12       ` Feyd
          @ 2006-01-06 16:25         ` Johannes Berg
            0 siblings, 0 replies; 14+ messages in thread
          From: Johannes Berg @ 2006-01-06 16:25 UTC (permalink / raw)
            To: Feyd; +Cc: bcm43xx-dev, netdev, linux-kernel
          
          [-- Attachment #1: Type: text/plain, Size: 852 bytes --]
          
          On Fri, 2006-01-06 at 17:12 +0100, Feyd wrote:
          > Michael Buesch wrote:
          > > The _real_ main point I wanted to make was to _not_ use a net_device for
          > > the master device. What else should be used for master device, let it
          > > be a device node or a netlink socket, is rather unimportant at
          > > this stage.
          > 
          > If the only purpose of the master device was configuration, then it
          > would be beter to use something other then a net_device, but you may
          > want to send/receive raw 802.11 packets from userspace, most logicaly
          > over a master interface.
          
          We thought about that for a while, but it may not be feasible. Certain
          hardware that manages more stuff than others in firmware/hardware may
          not allow sending raw frames without going into some special mode, which
          is better handled by adding some kind of raw virtual device.
          
          johannes
          
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          ^ permalink raw reply	[flat|nested] 14+ messages in thread

  • * Re: [Bcm43xx-dev] [Fwd: State of the Union: Wireless]
      2006-01-06 11:00 ` [Bcm43xx-dev] [Fwd: State of the Union: Wireless] Michael Buesch
      2006-01-06 11:38   ` Marcel Holtmann
    @ 2006-01-06 17:02   ` Ben Greear
      1 sibling, 0 replies; 14+ messages in thread
    From: Ben Greear @ 2006-01-06 17:02 UTC (permalink / raw)
      To: Michael Buesch; +Cc: jgarzik, bcm43xx-dev, netdev, linux-kernel
    
    Michael Buesch wrote:
    
    > How would the virtual interfaces look like? That is quite easy to answer.
    > They are net_devices, as they transfer data.
    > They should probaly _not_ be on top of the ethernet, as 80211 does not
    > have very much in common with ethernet. Basically they share the same
    > MAC address format. Does someone have another thing, which he thinks
    > is shared?
    
    If you can make the virtual devices look like ethernet, I believe a lot of other things
    will just work w/out hacking, including user-space apps that think they
    know exactly what an ethernet frame/device looks like.
    
    The only things I think of that won't work like ethernet is the ability to
    change the local MAC address or go into promisc mode.  And, it's always possible
    that future wifi hardware will support that as well.  Either way, the current
    API handles this fine:  the requests to change will just fail with a convenient error.
    
    Ben
    
    -- 
    Ben Greear <greearb@candelatech•com>
    Candela Technologies Inc  http://www.candelatech.com
    
    ^ permalink raw reply	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2006-01-12 14:20 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
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2006-01-06 11:00 ` [Bcm43xx-dev] [Fwd: State of the Union: Wireless] Michael Buesch
2006-01-06 11:38   ` Marcel Holtmann
2006-01-06 11:45     ` Michael Buesch
2006-01-06 12:10       ` [Bcm43xx-dev] " Marcel Holtmann
2006-01-06 12:46         ` Patrick McHardy
2006-01-06 18:23           ` Stephen Hemminger
2006-01-06 22:16           ` David Lang
2006-01-06 22:18             ` David S. Miller
2006-01-09 18:24               ` Ingo Oeser
2006-01-06 22:22             ` Patrick McHardy
2006-01-12 14:20           ` Harald Welte
2006-01-06 16:12       ` Feyd
2006-01-06 16:25         ` Johannes Berg
2006-01-06 17:02   ` Ben Greear

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