Doubt on packet generation in kernel space.

Doubt on packet generation in kernel space.

[varun]

Hi all

Iam a newbie and iam basically interested in generation my own
icmp packet in the kernel space using skb. That is iam aware that this
can be done using raw or packet socket from user space.         But to
do it from kernel space is it possible if yes how to go
about it. i believe that what raw socket call from User space does in
kernel thats what iam supposed to do.(Correct me if iam wrong). I think
i might have to build my own skb and put it in transmit queue. Is it
possible? Iam also aware that there are some packet generation module
that is inbuilt as per the Documentation in linux kernel states. But i
dont want to use that instead i want to create my own module that will
allow me generate the icmp packet. Please help!!

                                                            Varun

Re: Doubt on packet generation in kernel space.

[Jesse Peng]

Dear Varun:

It depends on whether your code is in process context or interupt context.
Maybe you will elaberate the situation you generate the icmp packet?It will
help more for others to help..

Your sincerely
Jesse



----- Original Message -----
From: "varun" <varun@rocsys.com>
To: <netfilter-devel@lists.netfilter.org>
Sent: Thursday, August 11, 2005 2:33 PM
Subject: Doubt on packet generation in kernel space.


> Hi all
>
> Iam a newbie and iam basically interested in generation my own
> icmp packet in the kernel space using skb. That is iam aware that this
> can be done using raw or packet socket from user space.         But to
> do it from kernel space is it possible if yes how to go
> about it. i believe that what raw socket call from User space does in
> kernel thats what iam supposed to do.(Correct me if iam wrong). I think
> i might have to build my own skb and put it in transmit queue. Is it
> possible? Iam also aware that there are some packet generation module
> that is inbuilt as per the Documentation in linux kernel states. But i
> dont want to use that instead i want to create my own module that will
> allow me generate the icmp packet. Please help!!
>
>                                                             Varun
>
>

Re: Doubt on packet generation in kernel space.

[varun]

Hi jesse,

           Let me explain my requirement. I have a kernel module which
is basically maintaining some network database of what are the MAC and
Ip of each of the system in the network. Now with the help of a
character pseudo driver, my user program will send an request to the
kernel module to generate the icmp (ping) packet to a particular host
from the maintained kernel database. It is on this event that the packet
generator module comes into picture where in the inputs to the module is
IP and based on this the i might get a response from the destination
system and i will compare the MACs to see if they are equal. So for this
requirement i need a packet generator to handle this event. Only an icmp
packet is enough.

                 Thanx in advance.
                                                       Varun 


On Fri, 2005-08-12 at 13:45, Jesse Peng wrote:
> Dear Varun:
> 
> It depends on whether your code is in process context or interupt context.
> Maybe you will elaberate the situation you generate the icmp packet?It will
> help more for others to help..
> 
> Your sincerely
> Jesse
> 
> 
> 
> ----- Original Message -----
> From: "varun" <varun@rocsys.com>
> To: <netfilter-devel@lists.netfilter.org>
> Sent: Thursday, August 11, 2005 2:33 PM
> Subject: Doubt on packet generation in kernel space.
> 
> 
> > Hi all
> >
> > Iam a newbie and iam basically interested in generation my own
> > icmp packet in the kernel space using skb. That is iam aware that this
> > can be done using raw or packet socket from user space.         But to
> > do it from kernel space is it possible if yes how to go
> > about it. i believe that what raw socket call from User space does in
> > kernel thats what iam supposed to do.(Correct me if iam wrong). I think
> > i might have to build my own skb and put it in transmit queue. Is it
> > possible? Iam also aware that there are some packet generation module
> > that is inbuilt as per the Documentation in linux kernel states. But i
> > dont want to use that instead i want to create my own module that will
> > allow me generate the icmp packet. Please help!!
> >
> >                                                             Varun
> >
> >

Re: Doubt on packet generation in kernel space.

[JessePeng]

Dear Varun:

How will you handle the response?Actually,that's derived from how you manage
your "probe by icmp" machenism.It looks not simple as hacking an icmp
packet!

Your sincerely
Jesse
----- Original Message -----
From: "varun" <varun@rocsys.com>
To: "Jesse Peng" <jesse@deansoft.com.tw>
Cc: "netfilters" <netfilter-devel@lists.netfilter.org>
Sent: Friday, August 12, 2005 7:23 PM
Subject: Re: Doubt on packet generation in kernel space.


> Hi jesse,
>
>            Let me explain my requirement. I have a kernel module which
> is basically maintaining some network database of what are the MAC and
> Ip of each of the system in the network. Now with the help of a
> character pseudo driver, my user program will send an request to the
> kernel module to generate the icmp (ping) packet to a particular host
> from the maintained kernel database. It is on this event that the packet
> generator module comes into picture where in the inputs to the module is
> IP and based on this the i might get a response from the destination
> system and i will compare the MACs to see if they are equal. So for this
> requirement i need a packet generator to handle this event. Only an icmp
> packet is enough.
>
>                  Thanx in advance.
>                                                        Varun
>
>
> On Fri, 2005-08-12 at 13:45, Jesse Peng wrote:
> > Dear Varun:
> >
> > It depends on whether your code is in process context or interupt
context.
> > Maybe you will elaberate the situation you generate the icmp packet?It
will
> > help more for others to help..
> >
> > Your sincerely
> > Jesse
> >
> >
> >
> > ----- Original Message -----
> > From: "varun" <varun@rocsys.com>
> > To: <netfilter-devel@lists.netfilter.org>
> > Sent: Thursday, August 11, 2005 2:33 PM
> > Subject: Doubt on packet generation in kernel space.
> >
> >
> > > Hi all
> > >
> > > Iam a newbie and iam basically interested in generation my own
> > > icmp packet in the kernel space using skb. That is iam aware that this
> > > can be done using raw or packet socket from user space.         But to
> > > do it from kernel space is it possible if yes how to go
> > > about it. i believe that what raw socket call from User space does in
> > > kernel thats what iam supposed to do.(Correct me if iam wrong). I
think
> > > i might have to build my own skb and put it in transmit queue. Is it
> > > possible? Iam also aware that there are some packet generation module
> > > that is inbuilt as per the Documentation in linux kernel states. But i
> > > dont want to use that instead i want to create my own module that will
> > > allow me generate the icmp packet. Please help!!
> > >
> > >                                                             Varun
> > >
> > >
>

Re: Doubt on packet generation in kernel space.

[varun]

Hi Jesse,
On Mon, 2005-08-15 at 10:18, JessePeng wrote:
> Dear Varun:
> 
> How will you handle the response?Actually,that's derived from how you manage
> your "probe by icmp" machenism.It looks not simple as hacking an icmp
> packet!
> Pardon me if iam wrong but what i was thinking is i can use netfilters 
  or dev_add_pack() and capture packets and take only packets with icmp
header and compare it. I dont know if it possible...Can i know what
might be the complications involved in it?
  You said "probe by icmp" mechanism ---Can you give me any suggestions
for this?
                                                            Varun


> Your sincerely
> Jesse
> ----- Original Message -----
> From: "varun" <varun@rocsys.com>
> To: "Jesse Peng" <jesse@deansoft.com.tw>
> Cc: "netfilters" <netfilter-devel@lists.netfilter.org>
> Sent: Friday, August 12, 2005 7:23 PM
> Subject: Re: Doubt on packet generation in kernel space.
> 
> 
> > Hi jesse,
> >
> >            Let me explain my requirement. I have a kernel module which
> > is basically maintaining some network database of what are the MAC and
> > Ip of each of the system in the network. Now with the help of a
> > character pseudo driver, my user program will send an request to the
> > kernel module to generate the icmp (ping) packet to a particular host
> > from the maintained kernel database. It is on this event that the packet
> > generator module comes into picture where in the inputs to the module is
> > IP and based on this the i might get a response from the destination
> > system and i will compare the MACs to see if they are equal. So for this
> > requirement i need a packet generator to handle this event. Only an icmp
> > packet is enough.
> >
> >                  Thanx in advance.
> >                                                        Varun
> >
> >
> > On Fri, 2005-08-12 at 13:45, Jesse Peng wrote:
> > > Dear Varun:
> > >
> > > It depends on whether your code is in process context or interupt
> context.
> > > Maybe you will elaberate the situation you generate the icmp packet?It
> will
> > > help more for others to help..
> > >
> > > Your sincerely
> > > Jesse
> > >
> > >
> > >
> > > ----- Original Message -----
> > > From: "varun" <varun@rocsys.com>
> > > To: <netfilter-devel@lists.netfilter.org>
> > > Sent: Thursday, August 11, 2005 2:33 PM
> > > Subject: Doubt on packet generation in kernel space.
> > >
> > >
> > > > Hi all
> > > >
> > > > Iam a newbie and iam basically interested in generation my own
> > > > icmp packet in the kernel space using skb. That is iam aware that this
> > > > can be done using raw or packet socket from user space.         But to
> > > > do it from kernel space is it possible if yes how to go
> > > > about it. i believe that what raw socket call from User space does in
> > > > kernel thats what iam supposed to do.(Correct me if iam wrong). I
> think
> > > > i might have to build my own skb and put it in transmit queue. Is it
> > > > possible? Iam also aware that there are some packet generation module
> > > > that is inbuilt as per the Documentation in linux kernel states. But i
> > > > dont want to use that instead i want to create my own module that will
> > > > allow me generate the icmp packet. Please help!!
> > > >
> > > >                                                             Varun
> > > >
> > > >
> >

Re: Doubt on packet generation in kernel space.

[Jesse Peng]

Dear Varun:

Sorry for replying late.Please forget anything that I mentioned about
icmp.Accroding to your scenario,unless any special case you would taken into
account,others will resort to arp solution.Since the key issues are all
within arp domain.Let me share my idea as following:
I supposed the MAC-ip database you maintained are derived from arp_table,and
__neigh_lookup are used to keep it updated.Then to serve the ip-mac updating
request,arp_send is used to send your arp request.And since this is
netfilter list where you look for things,then I suggest you take care the
reponse by hooking at NF_ARP_IN,which is at NF_ARP.
Hope things help!

Your sincerely
Jesse

----- Original Message -----
From: "varun" <varun@rocsys.com>
To: "JessePeng" <jesse@deansoft.com.tw>
Cc: "netfilters" <netfilter-devel@lists.netfilter.org>
Sent: Tuesday, August 16, 2005 11:30 AM
Subject: Re: Doubt on packet generation in kernel space.


> Hi Jesse,
> On Mon, 2005-08-15 at 10:18, JessePeng wrote:
> > Dear Varun:
> >
> > How will you handle the response?Actually,that's derived from how you
manage
> > your "probe by icmp" machenism.It looks not simple as hacking an icmp
> > packet!
> > Pardon me if iam wrong but what i was thinking is i can use netfilters
>   or dev_add_pack() and capture packets and take only packets with icmp
> header and compare it. I dont know if it possible...Can i know what
> might be the complications involved in it?
>   You said "probe by icmp" mechanism ---Can you give me any suggestions
> for this?
>                                                             Varun
>
>
> > Your sincerely
> > Jesse
> > ----- Original Message -----
> > From: "varun" <varun@rocsys.com>
> > To: "Jesse Peng" <jesse@deansoft.com.tw>
> > Cc: "netfilters" <netfilter-devel@lists.netfilter.org>
> > Sent: Friday, August 12, 2005 7:23 PM
> > Subject: Re: Doubt on packet generation in kernel space.
> >
> >
> > > Hi jesse,
> > >
> > >            Let me explain my requirement. I have a kernel module which
> > > is basically maintaining some network database of what are the MAC and
> > > Ip of each of the system in the network. Now with the help of a
> > > character pseudo driver, my user program will send an request to the
> > > kernel module to generate the icmp (ping) packet to a particular host
> > > from the maintained kernel database. It is on this event that the
packet
> > > generator module comes into picture where in the inputs to the module
is
> > > IP and based on this the i might get a response from the destination
> > > system and i will compare the MACs to see if they are equal. So for
this
> > > requirement i need a packet generator to handle this event. Only an
icmp
> > > packet is enough.
> > >
> > >                  Thanx in advance.
> > >                                                        Varun
> > >
> > >
> > > On Fri, 2005-08-12 at 13:45, Jesse Peng wrote:
> > > > Dear Varun:
> > > >
> > > > It depends on whether your code is in process context or interupt
> > context.
> > > > Maybe you will elaberate the situation you generate the icmp
packet?It
> > will
> > > > help more for others to help..
> > > >
> > > > Your sincerely
> > > > Jesse
> > > >
> > > >
> > > >
> > > > ----- Original Message -----
> > > > From: "varun" <varun@rocsys.com>
> > > > To: <netfilter-devel@lists.netfilter.org>
> > > > Sent: Thursday, August 11, 2005 2:33 PM
> > > > Subject: Doubt on packet generation in kernel space.
> > > >
> > > >
> > > > > Hi all
> > > > >
> > > > > Iam a newbie and iam basically interested in generation my own
> > > > > icmp packet in the kernel space using skb. That is iam aware that
this
> > > > > can be done using raw or packet socket from user space.
But to
> > > > > do it from kernel space is it possible if yes how to go
> > > > > about it. i believe that what raw socket call from User space does
in
> > > > > kernel thats what iam supposed to do.(Correct me if iam wrong). I
> > think
> > > > > i might have to build my own skb and put it in transmit queue. Is
it
> > > > > possible? Iam also aware that there are some packet generation
module
> > > > > that is inbuilt as per the Documentation in linux kernel states.
But i
> > > > > dont want to use that instead i want to create my own module that
will
> > > > > allow me generate the icmp packet. Please help!!
> > > > >
> > > > >                                                             Varun
> > > > >
> > > > >
> > >

Re: Doubt on packet generation in kernel space.

[varun]

Hi jesse,

          I was not at home so i didnt check mail. Anyway thanx for your
help. I understand that instead of sending icmp if i can send an arp
packet using arp_send() (correct me if iam wrong) and maintain that
database. You also said if register with NF_ARP_IN that ill be able to
get all the arp packet.So in other words what you are asking me to do is
to build my own arp request and wait for the response. On based on the
response i should be able to update my table.I have a doubt here that is
if i register with NF_ARP_IN then i might get even packets that are arp
request from other host am i correct? If so is there any way i can make
sure that i get only response for the arp-request i sent? I guess i
might have write a logic to filter it myself is it?
Can you tell me what happens if the host to which i sent an arp request
is not reachable?I will not get the response so i must wait for sometime
and time out?

                sorry for asking lot of questions. If possible please
help me. actually i planned of using arp but for the above reasons i
opted for icmp.

                                                     Varun  









On Thu, 2005-08-18 at 13:17, Jesse Peng wrote:
> Dear Varun:
> 
> Sorry for replying late.Please forget anything that I mentioned about
> icmp.Accroding to your scenario,unless any special case you would taken into
> account,others will resort to arp solution.Since the key issues are all
> within arp domain.Let me share my idea as following:
> I supposed the MAC-ip database you maintained are derived from arp_table,and
> __neigh_lookup are used to keep it updated.Then to serve the ip-mac updating
> request,arp_send is used to send your arp request.And since this is
> netfilter list where you look for things,then I suggest you take care the
> reponse by hooking at NF_ARP_IN,which is at NF_ARP.
> Hope things help!
> 
> Your sincerely
> Jesse
> 
> ----- Original Message -----
> From: "varun" <varun@rocsys.com>
> To: "JessePeng" <jesse@deansoft.com.tw>
> Cc: "netfilters" <netfilter-devel@lists.netfilter.org>
> Sent: Tuesday, August 16, 2005 11:30 AM
> Subject: Re: Doubt on packet generation in kernel space.
> 
> 
> > Hi Jesse,
> > On Mon, 2005-08-15 at 10:18, JessePeng wrote:
> > > Dear Varun:
> > >
> > > How will you handle the response?Actually,that's derived from how you
> manage
> > > your "probe by icmp" machenism.It looks not simple as hacking an icmp
> > > packet!
> > > Pardon me if iam wrong but what i was thinking is i can use netfilters
> >   or dev_add_pack() and capture packets and take only packets with icmp
> > header and compare it. I dont know if it possible...Can i know what
> > might be the complications involved in it?
> >   You said "probe by icmp" mechanism ---Can you give me any suggestions
> > for this?
> >                                                             Varun
> >
> >
> > > Your sincerely
> > > Jesse
> > > ----- Original Message -----
> > > From: "varun" <varun@rocsys.com>
> > > To: "Jesse Peng" <jesse@deansoft.com.tw>
> > > Cc: "netfilters" <netfilter-devel@lists.netfilter.org>
> > > Sent: Friday, August 12, 2005 7:23 PM
> > > Subject: Re: Doubt on packet generation in kernel space.
> > >
> > >
> > > > Hi jesse,
> > > >
> > > >            Let me explain my requirement. I have a kernel module which
> > > > is basically maintaining some network database of what are the MAC and
> > > > Ip of each of the system in the network. Now with the help of a
> > > > character pseudo driver, my user program will send an request to the
> > > > kernel module to generate the icmp (ping) packet to a particular host
> > > > from the maintained kernel database. It is on this event that the
> packet
> > > > generator module comes into picture where in the inputs to the module
> is
> > > > IP and based on this the i might get a response from the destination
> > > > system and i will compare the MACs to see if they are equal. So for
> this
> > > > requirement i need a packet generator to handle this event. Only an
> icmp
> > > > packet is enough.
> > > >
> > > >                  Thanx in advance.
> > > >                                                        Varun
> > > >
> > > >
> > > > On Fri, 2005-08-12 at 13:45, Jesse Peng wrote:
> > > > > Dear Varun:
> > > > >
> > > > > It depends on whether your code is in process context or interupt
> > > context.
> > > > > Maybe you will elaberate the situation you generate the icmp
> packet?It
> > > will
> > > > > help more for others to help..
> > > > >
> > > > > Your sincerely
> > > > > Jesse
> > > > >
> > > > >
> > > > >
> > > > > ----- Original Message -----
> > > > > From: "varun" <varun@rocsys.com>
> > > > > To: <netfilter-devel@lists.netfilter.org>
> > > > > Sent: Thursday, August 11, 2005 2:33 PM
> > > > > Subject: Doubt on packet generation in kernel space.
> > > > >
> > > > >
> > > > > > Hi all
> > > > > >
> > > > > > Iam a newbie and iam basically interested in generation my own
> > > > > > icmp packet in the kernel space using skb. That is iam aware that
> this
> > > > > > can be done using raw or packet socket from user space.
> But to
> > > > > > do it from kernel space is it possible if yes how to go
> > > > > > about it. i believe that what raw socket call from User space does
> in
> > > > > > kernel thats what iam supposed to do.(Correct me if iam wrong). I
> > > think
> > > > > > i might have to build my own skb and put it in transmit queue. Is
> it
> > > > > > possible? Iam also aware that there are some packet generation
> module
> > > > > > that is inbuilt as per the Documentation in linux kernel states.
> But i
> > > > > > dont want to use that instead i want to create my own module that
> will
> > > > > > allow me generate the icmp packet. Please help!!
> > > > > >
> > > > > >                                                             Varun
> > > > > >
> > > > > >
> > > >

Re: Doubt on packet generation in kernel space.

[Jesse Peng]

----- Original Message -----
From: "Jesse Peng" <Jesse@deansoft.com.tw>
To: "varun" <varun@rocsys.com>
Sent: Wednesday, August 24, 2005 4:43 PM
Subject: Re: Doubt on packet generation in kernel space.


> Dear Varun:
> According to linux networking kernel,before an ip packet successfully
being
> transmitted,the arp_table should be updated(if lack of) for the ip-mac
pair
> maintained in neighbour structure.So no matter how you trigger to update
> your ip-mac database,the kernel still need to update its arp_table.That's
> why directly using arp solution is suggested.
> Nevertheless,before neighbour being updated for the MAC,all your icmp
> requesting packet can do is waiting at the neighbour queue and get no
> transmitted.
> And think of a rare case,what if the target doesn't response to icmp
packet?
> Finally,I don't see things prevent you from arp solution  really prevent.
>
> Hope these suggestions help!
>
> Your sincerely
> Jesse
>
> ----- Original Message -----
> From: "varun" <varun@rocsys.com>
> To: "Jesse Peng" <jesse@deansoft.com.tw>
> Cc: "netfilters" <netfilter-devel@lists.netfilter.org>
> Sent: Tuesday, August 23, 2005 11:53 AM
> Subject: Re: Doubt on packet generation in kernel space.
>
>
> > Hi jesse,
> >
> >           I was not at home so i didnt check mail. Anyway thanx for your
> > help. I understand that instead of sending icmp if i can send an arp
> > packet using arp_send() (correct me if iam wrong) and maintain that
> > database. You also said if register with NF_ARP_IN that ill be able to
> > get all the arp packet.So in other words what you are asking me to do is
> > to build my own arp request and wait for the response. On based on the
> > response i should be able to update my table.I have a doubt here that is
> > if i register with NF_ARP_IN then i might get even packets that are arp
> > request from other host am i correct? If so is there any way i can make
> > sure that i get only response for the arp-request i sent? I guess i
> > might have write a logic to filter it myself is it?
> > Can you tell me what happens if the host to which i sent an arp request
> > is not reachable?I will not get the response so i must wait for sometime
> > and time out?
> >
> >                 sorry for asking lot of questions. If possible please
> > help me. actually i planned of using arp but for the above reasons i
> > opted for icmp.
> >
> >                                                      Varun
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > On Thu, 2005-08-18 at 13:17, Jesse Peng wrote:
> > > Dear Varun:
> > >
> > > Sorry for replying late.Please forget anything that I mentioned about
> > > icmp.Accroding to your scenario,unless any special case you would
taken
> into
> > > account,others will resort to arp solution.Since the key issues are
all
> > > within arp domain.Let me share my idea as following:
> > > I supposed the MAC-ip database you maintained are derived from
> arp_table,and
> > > __neigh_lookup are used to keep it updated.Then to serve the ip-mac
> updating
> > > request,arp_send is used to send your arp request.And since this is
> > > netfilter list where you look for things,then I suggest you take care
> the
> > > reponse by hooking at NF_ARP_IN,which is at NF_ARP.
> > > Hope things help!
> > >
> > > Your sincerely
> > > Jesse
> > >
> > > ----- Original Message -----
> > > From: "varun" <varun@rocsys.com>
> > > To: "JessePeng" <jesse@deansoft.com.tw>
> > > Cc: "netfilters" <netfilter-devel@lists.netfilter.org>
> > > Sent: Tuesday, August 16, 2005 11:30 AM
> > > Subject: Re: Doubt on packet generation in kernel space.
> > >
> > >
> > > > Hi Jesse,
> > > > On Mon, 2005-08-15 at 10:18, JessePeng wrote:
> > > > > Dear Varun:
> > > > >
> > > > > How will you handle the response?Actually,that's derived from how
> you
> > > manage
> > > > > your "probe by icmp" machenism.It looks not simple as hacking an
> icmp
> > > > > packet!
> > > > > Pardon me if iam wrong but what i was thinking is i can use
> netfilters
> > > >   or dev_add_pack() and capture packets and take only packets with
> icmp
> > > > header and compare it. I dont know if it possible...Can i know what
> > > > might be the complications involved in it?
> > > >   You said "probe by icmp" mechanism ---Can you give me any
> suggestions
> > > > for this?
> > > >                                                             Varun
> > > >
> > > >
> > > > > Your sincerely
> > > > > Jesse
> > > > > ----- Original Message -----
> > > > > From: "varun" <varun@rocsys.com>
> > > > > To: "Jesse Peng" <jesse@deansoft.com.tw>
> > > > > Cc: "netfilters" <netfilter-devel@lists.netfilter.org>
> > > > > Sent: Friday, August 12, 2005 7:23 PM
> > > > > Subject: Re: Doubt on packet generation in kernel space.
> > > > >
> > > > >
> > > > > > Hi jesse,
> > > > > >
> > > > > >            Let me explain my requirement. I have a kernel module
> which
> > > > > > is basically maintaining some network database of what are the
MAC
> and
> > > > > > Ip of each of the system in the network. Now with the help of a
> > > > > > character pseudo driver, my user program will send an request to
> the
> > > > > > kernel module to generate the icmp (ping) packet to a particular
> host
> > > > > > from the maintained kernel database. It is on this event that
the
> > > packet
> > > > > > generator module comes into picture where in the inputs to the
> module
> > > is
> > > > > > IP and based on this the i might get a response from the
> destination
> > > > > > system and i will compare the MACs to see if they are equal. So
> for
> > > this
> > > > > > requirement i need a packet generator to handle this event. Only
> an
> > > icmp
> > > > > > packet is enough.
> > > > > >
> > > > > >                  Thanx in advance.
> > > > > >                                                        Varun
> > > > > >
> > > > > >
> > > > > > On Fri, 2005-08-12 at 13:45, Jesse Peng wrote:
> > > > > > > Dear Varun:
> > > > > > >
> > > > > > > It depends on whether your code is in process context or
> interupt
> > > > > context.
> > > > > > > Maybe you will elaberate the situation you generate the icmp
> > > packet?It
> > > > > will
> > > > > > > help more for others to help..
> > > > > > >
> > > > > > > Your sincerely
> > > > > > > Jesse
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > ----- Original Message -----
> > > > > > > From: "varun" <varun@rocsys.com>
> > > > > > > To: <netfilter-devel@lists.netfilter.org>
> > > > > > > Sent: Thursday, August 11, 2005 2:33 PM
> > > > > > > Subject: Doubt on packet generation in kernel space.
> > > > > > >
> > > > > > >
> > > > > > > > Hi all
> > > > > > > >
> > > > > > > > Iam a newbie and iam basically interested in generation my
own
> > > > > > > > icmp packet in the kernel space using skb. That is iam aware
> that
> > > this
> > > > > > > > can be done using raw or packet socket from user space.
> > > But to
> > > > > > > > do it from kernel space is it possible if yes how to go
> > > > > > > > about it. i believe that what raw socket call from User
space
> does
> > > in
> > > > > > > > kernel thats what iam supposed to do.(Correct me if iam
> wrong). I
> > > > > think
> > > > > > > > i might have to build my own skb and put it in transmit
queue.
> Is
> > > it
> > > > > > > > possible? Iam also aware that there are some packet
generation
> > > module
> > > > > > > > that is inbuilt as per the Documentation in linux kernel
> states.
> > > But i
> > > > > > > > dont want to use that instead i want to create my own module
> that
> > > will
> > > > > > > > allow me generate the icmp packet. Please help!!
> > > > > > > >
> > > > > > > >
> Varun
> > > > > > > >
> > > > > > > >
> > > > > >
>