Hi
I am getting error when getting the 'rt'(route entry) using
'ip_route_output'.
I do not know why 'ip_route_output' is failing even when all params are
correct and
and required route is present for the passed source&dest ip addresses.
What value we should give for the field 'tos'.
I am passing the params &rt,destIp,SrcIP,0,0.
-- venu.m
----- Original Message -----
From: "Ravi Kumar" <ravivsn@rocsys.com>
To: "venum" <venum@intoto.com>
Cc: <kernelnewbies@nl.linux.org>
Sent: Monday, July 05, 2004 3:35 AM
Subject: Re: netif_rx dropping the packet
> Hi Venu Maya,
> May be you know that there are differenet types of NF_HOOKS. If a
> firewall wants to hook for packets, generally they do at Pre-routing and
> post routing. In the virtual tunnel, you create, the packets will be of
> SELF to OUTGOING type. The in and outgoing self packets will defnitely
> hit the above hooks. So, you need not bother about Netfilter hooks. You
> can use IPTUNNEL_XMIT macro ,defined in ipip.h
>
> #define IPTUNNEL_XMIT() do { \
> int err; \
> int pkt_len = skb->len; \
> \
> skb->ip_summed = CHECKSUM_NONE; \
> iph->tot_len = htons(skb->len); \
> printk("<1>Total Length:%d\n",skb->len); \
> ip_select_ident(iph, &rt->u.dst, NULL); \
> ip_send_check(iph); \
> err = NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL,
> rt->u.dst.dev, do_ip_send); \
> } while (0)
>
> static inline int do_ip_send(struct sk_buff *skb)
> {
> return ip_send(skb);
> }
>
> Cheers,
> -Ravi
> ROCSYS Technologies Ltd.,
> http://www.rocsys.com
>
>
> venum wrote:
>
> >Hi Ravi Kumar,
> >
> >Thanks for the response.
> >I am encapsulating the packet in the dummy ethernet device.
> >>From the Send function of this dummy device,I am passing the packet to
the
> >stack using 'netif_rx' so that it will go through all the 'net filter'
> >hooks.
> >I do not know if I can use 'ip_send' for the same purpose.
> >
> >--- venu maya
> >
> >----- Original Message -----
> >From: "Ravi Kumar" <ravivsn@rocsys.com>
> >To: "venum" <venum@intoto.com>
> >Cc: <kernelnewbies@nl.linux.org>
> >Sent: Monday, July 05, 2004 9:52 AM
> >Subject: Re: netif_rx dropping the packet
> >
> >
> >
> >
> >>Hi Venu Maya,
> >> There are numerous ways to take in packet. Apart from netfilter hooks,
> >>dev_add_pack and ether hooks , packets can also taken by creating dummy
> >>ethernet device.
> >>As I understand, the problem is in encapsulation module. You would like
> >>to see ipip.c/ip_gre.c as a proof of concept. After you attach the IP
> >>header+ UDP Header + Your payload, and based on route look up , you get
> >>device onto which the packet has to be sent to. use ip_send to send
> >>packets to stack. (Refer to ipip.h, you can use IPTUNNEL_XMIT )
> >>
> >>/* remember this to set in sk_buff */
> >>skb->dst = &rt->u.dst;
> >>
> >>Let me know how it goes,
> >>-Ravi
> >>ROCSYS Technologies Ltd
> >>http://www.rocsys.com
> >>
> >>bhaskar wrote:
> >>
> >>
> >>
> >>>Hi,
> >>>How did you capture the packet. I mean netfilter hooks, or using
> >>>dev_add_pack or ....
> >>>
> >>>Regards
> >>>bhaskar
> >>>
> >>>
> >>>venum wrote:
> >>>
> >>>
> >>>
> >>>>Hi
> >>>>
> >>>>I am facing a problem with the part of kernel code that I am
> >>>>developing for
> >>>>a linux router. The objective is to encapsulate the received IP
> >>>>packet with
> >>>>a UDP header and an extra IP header and forward it to a different
> >>>>destination.
> >>>>I am encapsulating the original packet and passing it to the stack
> >>>>
> >>>>
> >using
> >
> >
> >>>>'netif_rx'. I want the stack to forward the packet to changed
> >>>>destination.
> >>>>At the destination the packet will be decapsulated.
> >>>>But once the packet is given to the 'netif_rx', stack is dropping the
> >>>>packet
> >>>>silently.
> >>>>I don't know which part of the stack code is dropping the packet.
> >>>>
> >>>>I need help in debugging this problem.I am giving the following
details
> >>>>about the encapsulation:
> >>>>
> >>>>Dump of the ICMP ping packet received:
> >>>>0 0 24 c0 2d 63 0 80 48 18 9e 5a 8 0 45 0
> >>>>0 3c 1 cb 0 0 80 1 dc 18 ac 10 2 5c ac 10
> >>>>2 61 8 0 4a 5c 2 0 1 0 61 62 63 64 65 66
> >>>>67 68 69 6a 6b 6c 6d 6e 6f 70 71 72 73 74 75 76
> >>>>77 61 62 63 64 65 66 67 68 69
> >>>>
> >>>>Packet Dump after Encapsulation: This packet is given to stack using
> >>>>'netif_rx'
> >>>>45 0 0 74 56 34 0 0 f0 11 ba 8b ac 10 16 1
> >>>>ac 10 16 3 d4 31 d4 31 0 8 0 0 1 1 1 11
> >>>>22 33 44 55 66 0 0 0 0 0 0 0 24 c0 2d 63
> >>>>0 80 48 18 9e 5a 8 0 45 0 0 3c 1 cb 0 0
> >>>>80 1 dc 18 ac 10 2 5c ac 10 2 61 8 0 4a 5c
> >>>>2 0 1 0 61 62 63 64 65 66 67 68 69 6a 6b 6c
> >>>>6d 6e 6f 70 71 72 73 74 75 76 77 61 62 63 64 65
> >>>>66 67 68 69
> >>>>I want this packet to be routed to IP address 172.16.22.3. The
required
> >>>>route is configured.
> >>>>Is any thing wrong in the above encapsulated packet ?
> >>>>I am modifiying the follwing skb params:
> >>>>
> >>>>pSkb->ip_summed = CHECKSUM_UNNECESSARY;
> >>>>/* I have tried others like NONE,HW with no improvements
> >>>>*/
> >>>>
> >>>>pSkb->protocol = htons(ETH_P_IP);
> >>>>/* Since it is always an IP packet */
> >>>>
> >>>>Can anyone help me find out the problem. I will provide any other
> >>>>details if
> >>>>required.
> >>>>
> >>>>TIA,
> >>>> venu maya
> >>>>
> >>>>
> >>>>
> >>>>--
> >>>>Kernelnewbies: Help each other learn about the Linux kernel.
> >>>>Archive: http://mail.nl.linux.org/kernelnewbies/
> >>>>FAQ: http://kernelnewbies.org/faq/
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>--
> >>>Kernelnewbies: Help each other learn about the Linux kernel.
> >>>Archive: http://mail.nl.linux.org/kernelnewbies/
> >>>FAQ: http://kernelnewbies.org/faq/
> >>>
> >>>
> >>>
> >>
> >>
> >>--
> >>Kernelnewbies: Help each other learn about the Linux kernel.
> >>Archive: http://mail.nl.linux.org/kernelnewbies/
> >>FAQ: http://kernelnewbies.org/faq/
> >>
> >>
> >
> >
> >--
> >Kernelnewbies: Help each other learn about the Linux kernel.
> >Archive: http://mail.nl.linux.org/kernelnewbies/
> >FAQ: http://kernelnewbies.org/faq/
> >
> >
> >
>
--
Kernelnewbies: Help each other learn about the Linux kernel.
Archive: http://mail.nl.linux.org/kernelnewbies/
FAQ: http://kernelnewbies.org/faq/
