Hi,
Thanks for the help.
Now I am receiving the UDP punt packets in the UDP application running on
Linux. However I am not able to send back the packets from UDP
applications, the packets are getting dropped on VPP.
Below is the trace -
*vpp> trace add tuntap-rx 10*
00:02:49:998097: ip4-input-no-checksum
UDP: 70.1.1.51 -> 70.1.1.58
tos 0x00, ttl 64, length 128, checksum 0x7596
fragment id 0x7668
UDP: 50000 -> 5000
length 108, checksum 0xec09
00:02:49:998098: ip4-drop
UDP: 70.1.1.51 -> 70.1.1.58
tos 0x00, ttl 64, length 128, checksum 0x7596
fragment id 0x7668
UDP: 50000 -> 5000
length 108, checksum 0xec09
00:02:49:998099: error-drop
ip4-input: ip4 adjacency drop
I browsed the code of* ip4_input_inline *and found that next0 value is
always filled as *5* in below function.
*#define
vlib_validate_buffer_enqueue_x1(vm,node,next_index,to_next,n_left_to_next,bi0,next0)*
next0(5) means ip4_drop :-
*ip4-input-no-checksum error-drop [0] tuntap-rx*
* error-punt [1]
tapcli-rx*
* ip4-lookup [2]
dpdk-input*
* ip4-lookup-multicast [3]
handoff-dispatch*
* ip4-icmp-error [4]*
* ip4-drop [5] *
next0 variable is filled as 5 by the function *vnet_get_config_data. *Please
let me know what is the purpose of net_get_config_data and how it
determines the next node??
*Regards*
*Prerit*
On Fri, Nov 18, 2016 at 8:21 PM, John Lo (loj) <l...@cisco.com> wrote:
> The tuntap-tx node in VPP does not save any data to support packet trace.
> That’s why you do see any packet trace after error-punt. -John
>
>
>
> *From:* vpp-dev-boun...@lists.fd.io [mailto:vpp-dev-boun...@lists.fd.io] *On
> Behalf Of *Dave Barach (dbarach)
> *Sent:* Friday, November 18, 2016 8:23 AM
> *To:* Prerit Jain <prerit.j...@gmail.com>
>
> *Cc:* vpp-dev@lists.fd.io
> *Subject:* Re: [vpp-dev] Fwd: Punting UDP packets to Kernel
>
>
>
> You saw the packets w/ tcpdump, right?
>
>
>
> Thanks… Dave
>
>
>
> *From:* Prerit Jain [mailto:prerit.j...@gmail.com <prerit.j...@gmail.com>]
>
> *Sent:* Friday, November 18, 2016 8:15 AM
> *To:* Dave Barach (dbarach) <dbar...@cisco.com>
> *Cc:* vpp-dev@lists.fd.io
> *Subject:* Re: [vpp-dev] Fwd: Punting UDP packets to Kernel
>
>
>
>
>
> You mean that *ip4-udp-punt *node will directly write to tuntap
> interface for sending the packet to Kernel.
>
>
>
> On Fri, Nov 18, 2016 at 5:54 PM, Dave Barach (dbarach) <dbar...@cisco.com>
> wrote:
>
> Expected behavior.
>
>
>
> *From:* vpp-dev-boun...@lists.fd.io [mailto:vpp-dev-boun...@lists.fd.io] *On
> Behalf Of *Prerit Jain
> *Sent:* Friday, November 18, 2016 5:33 AM
> *To:* vpp-dev@lists.fd.io
> *Subject:* [vpp-dev] Fwd: Punting UDP packets to Kernel
>
>
>
>
>
>
>
> Thanks Dave.
>
>
>
> After adding below code in /etc/vpp/startup.conf
>
> tuntap {
>
> enable
>
> }
>
>
>
> I am able to capture the packets in kernel using tcpdump. However still
> the packet flow is terminating in *error-punt *in trace
>
> *...*
>
> *00:06:52:855592: ip4-local*
>
> * UDP: 70.1.1.58 -> 70.1.1.51*
>
> * tos 0x00, ttl 64, length 1028, checksum 0xcf79*
>
> * fragment id 0x1901*
>
> * UDP: 5000 -> 4500*
>
> * length 1008, checksum 0x8d26*
>
> *00:06:52:855592: ip4-udp-lookup*
>
> * UDP: src-port 5000 dst-port 4500*
>
> *00:06:52:855593: error-punt*
>
> * ip4-udp-punt: udp port punt*
>
>
>
> I do not see the node "tuntap-tx" in trace. While punting packet to
> kernel, the packet will not pass through "tuntap-tx" ??
>
>
>
>
>
>
>
> On Thu, Nov 17, 2016 at 11:30 PM, Dave Barach (dbarach) <dbar...@cisco.com>
> wrote:
>
> See .../vnet/vnet/unix/tuntap.c vs. .../vnet/vnet/unix/tapcli.c.
>
>
>
> Only the tuntap device is capable of punting packets to the linux stack
> through a tun interface. You picked the wrong one.
>
>
>
> Note that tuntap must be enabled explicitly from the vpp command line.
>
>
>
> Thanks… Dave
>
>
>
> *From:* vpp-dev-boun...@lists.fd.io [mailto:vpp-dev-boun...@lists.fd.io] *On
> Behalf Of *Prerit Jain
> *Sent:* Thursday, November 17, 2016 7:08 AM
> *To:* vpp-dev@lists.fd.io
> *Subject:* [vpp-dev] Punting UDP packets to Kernel
>
>
>
>
>
> I want to send UDP packets with port 4500 to Kernel.
>
>
>
> For that I send UDP packets from external interface (70.1.1.58:port 5000)
> to VPP host (70.1.1.51: 4500) and did below configuration.
>
>
>
> Set up the punt environment-
>
> * set punt udp 4500*
>
> Created the tap interface -
>
> * tap connect tap-0*
>
>
>
> *In the below capture VPP trace, the packet are not going beyond the node
> (**ip4-udp-punt) **to kernel.*
>
>
>
> *00:06:52:855590: dpdk-input*
>
> * GigabitEthernet1/0/2 rx queue 0*
>
> * buffer 0x174fcf: current data 14, length 1028, free-list 0, totlen-nifb
> 0, trace 0x9*
>
> * PKT MBUF: port 0, nb_segs 1, pkt_len 1042*
>
> * buf_len 2176, data_len 1042, ol_flags 0x0, data_off 128, phys_addr
> 0xd753b2c0*
>
> * packet_type 0x211*
>
> * Packet Types*
>
> * RTE_PTYPE_L2_ETHER (0x0001) Ethernet packet*
>
> * RTE_PTYPE_L3_IPV4 (0x0010) IPv4 packet without extension headers*
>
> * RTE_PTYPE_L4_UDP (0x0200) UDP packet*
>
> * IP4: ec:f4:bb:d5:68:a6 -> ec:f4:bb:c4:4d:46*
>
> * UDP: 70.1.1.58 -> 70.1.1.51*
>
> * tos 0x00, ttl 64, length 1028, checksum 0xcf79*
>
> * fragment id 0x1901*
>
> * UDP: 5000 -> 4500*
>
> * length 1008, checksum 0x8d26*
>
> *00:06:52:855591: ip4-input-no-checksum*
>
> * UDP: 70.1.1.58 -> 70.1.1.51*
>
> * tos 0x00, ttl 64, length 1028, checksum 0xcf79*
>
> * fragment id 0x1901*
>
> * UDP: 5000 -> 4500*
>
> * length 1008, checksum 0x8d26*
>
> *00:06:52:855592: ip4-lookup*
>
> * fib 0 dpo-idx 5 flow hash: 0x00000000*
>
> * UDP: 70.1.1.58 -> 70.1.1.51*
>
> * tos 0x00, ttl 64, length 1028, checksum 0xcf79*
>
> * fragment id 0x1901*
>
> * UDP: 5000 -> 4500*
>
> * length 1008, checksum 0x8d26*
>
> *00:06:52:855592: ip4-local*
>
> * UDP: 70.1.1.58 -> 70.1.1.51*
>
> * tos 0x00, ttl 64, length 1028, checksum 0xcf79*
>
> * fragment id 0x1901*
>
> * UDP: 5000 -> 4500*
>
> * length 1008, checksum 0x8d26*
>
> *00:06:52:855592: ip4-udp-lookup*
>
> * UDP: src-port 5000 dst-port 4500*
>
> *00:06:52:855593: error-punt*
>
> * ip4-udp-punt: udp port punt*
>
>
>
>
>
>
>
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