Hey Flavio I am so sorry for the inconvenience caused. Next time I will take care of it. You have been a great help for me. I thank you from the bottom of my heart. I was stuck on this part since last few days. Now, it has been resolved.
Thanks Krish On Wed, Feb 20, 2019 at 8:25 PM Flavio Leitner <f...@sysclose.org> wrote: > On Tue, Feb 19, 2019 at 12:43:08PM +0800, Krish wrote: > > Hi Flavio, > > > > I think I got tcp_src and tcp_dst values, I can also successfully print > > them. > > Here is what I did: > > for(numb=0;numb<cnt; numb++) > > { > > > > uint8_t nw_proto = 0; > > packet=packets->packets[numb]; > > size_t size = dp_packet_size(packet); > > const void *data = dp_packet_data(packet); > > const char *frame = (const char *)data; > > dp_packet_reset_offsets(packet); > > *data_pull(&data, &size, ETH_ADDR_LEN * 2);* > > //dl_type = parse_ether(&data, &size); > > //VLOG_DBG("parse ether type DL TYPE: 0x%4x", dl_type); > > packet->l3_ofs = (char *)data - frame; > > const struct ip_header *ip = dp_packet_l3(packet); > > nw_proto = ip->ip_proto; > > VLOG_DBG("IP proto---> %d ", nw_proto); > > int ip_len; > > ip_len = IP_IHL(ip->ip_ihl_ver) * 4; > > > > *data_pull(&data, &size, ip_len);* > > packet->l4_ofs = (char *)data - frame; > > if(nw_proto == 6) > > { > > struct tcp_header *th = dp_packet_l4(packet); > > VLOG_DBG( "tcp_src ---> %d", ntohs(th->tcp_src)); > > VLOG_DBG( "tcp_dst ---> %d", ntohs(th->tcp_dst)); > > } > > } > > > > > > Can you please confirm, if this is the right approach I have used and not > > seeing the old values like before? > > It's hard to read code using html (bold, etc), could you please use > text only and indent the code properly? It makes our life a lot easier. > > When you pull ETH_ADDR_LEN*2, the offset now points to ethernet_type > which is not the l3_ofs as you set next. I don't think the above code > works unless you uncomment parse_ethertype() which pulls more 4 bytes. > > fbl > > > > > > > Thank you so much, > > Krish > > > > On Tue, Feb 19, 2019 at 11:25 AM Krish <attkillro...@gmail.com> wrote: > > > > > Flavio, > > > > > > Thank you for the clarification. You explained it very well. > > > > > > I don't want to wait for the miniflow_extraction, so I am left with > > > parsing packet myself. > > > > > > Here is what I am doing now: > > > > > > for(numb=0;numb<cnt; numb++) > > > { > > > > > > uint8_t nw_proto; > > > const char *frame; > > > packet=packets->packets[numb]; > > > const void *data = dp_packet_data(packet); > > > frame = data; > > > *dp_packet_reset_offsets(packet);* > > > * packet->l3_ofs = (char *)data - frame;* > > > * const struct ip_header *ip = dp_packet_l3(packet);* > > > nw_proto = ip->ip_proto; > > > VLOG_DBG("IP proto---> %d ", nw_proto); // This is 0 > > > > > > } > > > > > > I followed almost the same approach of what is going in > miniflow_extract. > > > nw_proto(ip protocol) is printing out to be 0. > > > I am using this code just before emc_processing and inside > > > dp_netdev_input__. > > > Can you please help me here? > > > > > > Thanks > > > Krish > > > > > > > > > On Mon, Feb 18, 2019 at 8:11 PM Flavio Leitner <f...@sysclose.org> > wrote: > > > > > >> On Mon, Feb 18, 2019 at 11:05:53AM +0800, Krish wrote: > > >> > Thanks for reply Ben. > > >> > Does it mean that *miniflow_extract* will also initialize the L3 > header > > >> > pointer? > > >> > > >> If you look at the miniflow_extract(), you will see that it calls > > >> dp_packet_reset_offsets(packet) which will set all the header pointers > > >> to their defaults meaning that they are not pointing to anything real. > > >> > > >> These pointers are used by dp_packet_l3 (or 4) functions to locate > > >> the header. > > >> > > >> Then if you continue following the function, you will notice that > > >> the code parses the packet from the outer header to the inner header > > >> and as the parser goes, it updates the header offsets, like this line: > > >> > > >> packet->l3_ofs = (char *)data - frame; > > >> > > >> At this point, you have the pointer to the l3 header and you could use > > >> dp_packet_l3(). > > >> > > >> > > >> > But I am getting the correct values for *nw_proto* from the L3 > header. > > >> > struct ip_header *ip = dp_packet_l3(packet); > > >> > nw_proto = ip->ip_proto; > > >> > > > >> > Any comments on this? Whether its right or wrong? > > >> > > >> When using DPDK, the packet is represented by two parts. One if the > > >> rte buffer (packet data) that comes from DPDK library and the second > > >> part is the packet's metadata (the offsets you need). This offsets > > >> are allocated in the stack at dp_netdev_process_rxq_port(), so most > > >> probably you are seeing old values from previous packets which > > >> happens to work, but they are not correct. > > >> > > >> As I said above miniflow_extract() initializes those offsets to a > > >> known state and then parse the packet to update with the correct > > >> values. > > >> > > >> In summary, you will need to either wait for miniflow_extract() or > > >> parse the packet yourself if you need the tcp port. > > >> > > >> HTH, > > >> fbl > > >> > > >> > > >> > > >> > > > >> > Thanks a lot for your patience and response. > > >> > > > >> > Regards > > >> > > > >> > Krish > > >> > > > >> > On Sat, Feb 16, 2019 at 10:09 AM Ben Pfaff <b...@ovn.org> wrote: > > >> > > > >> > > You are almost certainly dereferencing a null pointer. > > >> > > > > >> > > On Sat, Feb 16, 2019 at 09:02:17AM +0800, Krish wrote: > > >> > > > That code I showed before. It is working fine and crashing only > > >> when I > > >> > > > enable debugging. > > >> > > > > > >> > > > As *sruct tcp_header's tcp_src* has ovs_be16 type. How to store > and > > >> print > > >> > > > this value ? > > >> > > > > > >> > > > Thanks > > >> > > > > > >> > > > On Sat, Feb 16, 2019, 08:43 Ben Pfaff <b...@ovn.org> wrote: > > >> > > > > > >> > > > > Then you're going to have to work harder since > miniflow_extract() > > >> is > > >> > > > > what initializes the L4 header pointer. > > >> > > > > > > >> > > > > On Sat, Feb 16, 2019 at 08:39:08AM +0800, Krish wrote: > > >> > > > > > I am sorry, but I am trying not to use extracted flow. I > want > > >> to use > > >> > > > > this > > >> > > > > > information before it goes to EMC. > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > On Sat, Feb 16, 2019, 03:44 Ben Pfaff <b...@ovn.org> wrote: > > >> > > > > > > > >> > > > > > > On Fri, Feb 15, 2019 at 03:48:22PM +0800, Krish wrote: > > >> > > > > > > > Hi > > >> > > > > > > > > > >> > > > > > > > I want to store tcp_src, dst port in a variable. > > >> > > > > > > > This is what I am doing: > > >> > > > > > > > 1. Retrieve packet from dp_packet_batch one by one. > > >> > > > > > > > 2. Retrieving field values by extracting packets > headers: > > >> > > > > > > > > > >> > > > > > > > struct ip_header *ip = dp_packet_l3(packet); > > >> > > > > > > > nw_proto = ip->ip_proto; > > >> > > > > > > > if(nw_proto == 6) > > >> > > > > > > > { > > >> > > > > > > > struct tcp_header *th = dp_packet_l4(packet); > > >> > > > > > > > // The following are the 2 different ways I am trying to > > >> print > > >> > > the > > >> > > > > > > tcp_src. > > >> > > > > > > > I have tried it 1 and 2 separately not at the same time. > > >> > > > > > > > //1 . Ovs crash at the below statement > > >> > > > > > > > uint16_t src = (uint16_t) > > >> ntohs(th->tcp_src); > > >> > > > > > > > VLOG_DBG( "tcp_src ---> %d", src ); > > >> > > > > > > > //2. When I enable logging ovs crashes > at > > >> this > > >> > > point > > >> > > > > > > > VLOG_DBG( "tcp_src ---> %d", > > >> ntohs(th->tcp_src) > > >> > > ); > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > } > > >> > > > > > > > > > >> > > > > > > > Can anyone please help how to store tcp_src port value > in a > > >> > > variable > > >> > > > > and > > >> > > > > > > > print it in vlogs? > > >> > > > > > > > Statement 2 is working fine if vlogs are disabled, but I > > >> want the > > >> > > > > port > > >> > > > > > > > value to be stored in a variable and then print. > > >> > > > > > > > > >> > > > > > > I'd just get it from the extracted flow instead of > inventing > > >> new > > >> > > code > > >> > > > > to > > >> > > > > > > extract it. > > >> > > > > > > > > >> > > > > > > >> > > > > >> > > >> > _______________________________________________ > > >> > discuss mailing list > > >> > disc...@openvswitch.org > > >> > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss > > >> > > >> > > >> > > > _______________________________________________ > > discuss mailing list > > disc...@openvswitch.org > > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss > > >
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