I see what you are saying now. I tried your solution and it works. Thanks a lot! On Apr 9, 2016 12:41 PM, "Jesper Wramberg" <jesper.wramberg at gmail.com> wrote:
> Assuming you are working on a standard Intel architecture or alike, the > constants you write are stored in little endian. > Network byte order is big endian, so for the UDP port (which is 16 bit > large) your code would be: > > udp_h->src_port = rte_cpu_to_be_16(88); > > Unless you actually want the port to be read as 22528 by the receiver ;-) > Check out the DPDK byte order API for your other constants. > > 2016-04-09 17:36 GMT+02:00 Murad Kablan <Murad.Kablan at colorado.edu>: > >> Hi Jesper, >> I'm not running DPDK on the receiving side. Just tcpdump. >> Can you please be more specific? What and how to convert to network byte >> order? >> >> Thanks >> On Apr 9, 2016 7:45 AM, "Jesper Wramberg" <jesper.wramberg at gmail.com> >> wrote: >> >>> Hey Murad, >>> >>> Are you running DPDK on the receiving end as well ? >>> In any case, I'm guessing you forgot to convert to network byte order ? >>> :-) >>> >>> >>> >>> 2016-04-09 12:34 GMT+02:00 Murad Kablan <Murad.Kablan at colorado.edu>: >>> >>>> Hi, >>>> I'm trying to change the IP and port of packets before sending them out. >>>> The captured packet in the receiving machines seems to be corrupted as >>>> the >>>> port is different than the one I inserted. Am I doing the checksum >>>> right? >>>> And do I need to do other HW configurations? >>>> >>>> This is my code: >>>> struct udp_hdr *udp_h; >>>> struct ipv4_hdr *ipv4_h; >>>> struct ether_hdr *eth_hdr; >>>> eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *); >>>> ipv4_h = (struct ipv4_hdr *)(eth_hdr + 1); >>>> udp_h = (struct udp_hdr *)((unsigned char *)ipv4_h + sizeof(struct >>>> ipv4_hdr)); >>>> >>>> ipv4_h->dst_addr = 6777226 //(gateway-ip 10.77.0.51) >>>> udp_h->src_port = 88 >>>> ipv4_h->hdr_checksum = 0; >>>> udp_h->dgram_cksum = 0; >>>> udp_h->dgram_cksum = rte_ipv4_udptcp_cksum(ipv4_h, udp_h); >>>> ipv4_h->hdr_checksum = rte_ipv4_cksum(ipv4_h); >>>> l2fwd_simple_forward(m, 0); >>>> >>>> Thanks, >>>> >>>> Murad >>>> >>> >>> >
