[dpdk-dev] Error : dereferencing pointer to incomplete type......
Hello friends, I get a error like "dereferencing pointer to incomplete type", when I try to fill in the IPv4 headers. Below is the code snippet: struct ether_hdr *ehdr = rte_pktmbuf_mtod(m_pool, struct ether_hdr *); struct ipv4_hdr *iphdr = (struct ipv4_hdr *)(&ehdr[1]); iphdr->packet_id = (uint16_t)0x0001; //This gives error. rte_bswap16(iphdr->packet_id,0x0001); //This format also gives the same error. And also what is the best way to copy an 8 bit (1 byte) value for fields like 'type_of_service' ? will rte_memcpy() work for it ? Thanks in advance
[dpdk-dev] Error : dereferencing pointer to incomplete type......
A little bit of correction on the second format: iphdr->packet_id = rte_bswap16(0x0001); // This one gives error as well Any idea on what could be wrong ? Thanks On Mon, Mar 17, 2014 at 1:51 PM, sabu kurian wrote: > Hello friends, > > I get a error like "dereferencing pointer to incomplete type", when I try > to fill in the IPv4 headers. > > Below is the code snippet: > > struct ether_hdr *ehdr = rte_pktmbuf_mtod(m_pool, struct ether_hdr *); > > struct ipv4_hdr *iphdr = (struct ipv4_hdr *)(&ehdr[1]); > > > iphdr->packet_id = (uint16_t)0x0001; //This gives error. > > rte_bswap16(iphdr->packet_id,0x0001); //This format also gives the same > error. > > And also what is the best way to copy an 8 bit (1 byte) value for fields > like 'type_of_service' ? will rte_memcpy() work for it ? > > > > Thanks in advance > >
[dpdk-dev] Error : dereferencing pointer to incomplete type......
Hi, Are you sure that this is the line that gives the error? How did you define m_pool? Regarding coping one byte, copy using simple assignment should be the most efficient way. If you want to make sure it is just 8 bits, do a bit wise and (& 0xff). Daniel On Mon, Mar 17, 2014 at 10:27 AM, sabu kurian wrote: > A little bit of correction on the second format: > > iphdr->packet_id = rte_bswap16(0x0001); // This one gives error as well > > Any idea on what could be wrong ? > > Thanks > > > > > > > On Mon, Mar 17, 2014 at 1:51 PM, sabu kurian > wrote: > > > Hello friends, > > > > I get a error like "dereferencing pointer to incomplete type", when I try > > to fill in the IPv4 headers. > > > > Below is the code snippet: > > > > struct ether_hdr *ehdr = rte_pktmbuf_mtod(m_pool, struct ether_hdr *); > > > > struct ipv4_hdr *iphdr = (struct ipv4_hdr *)(&ehdr[1]); > > > > > > iphdr->packet_id = (uint16_t)0x0001; //This gives error. > > > > rte_bswap16(iphdr->packet_id,0x0001); //This format also gives the same > > error. > > > > And also what is the best way to copy an 8 bit (1 byte) value for fields > > like 'type_of_service' ? will rte_memcpy() work for it ? > > > > > > > > Thanks in advance > > > > >
[dpdk-dev] Segmentation Fault on printf()
Sabu,
I think that in this case the packet length is zero which will result in
nothing from mtod.
Daniel
On Sun, Mar 16, 2014 at 3:03 PM, sabu kurian wrote:
> Hello chris,
>
> Thanks for your reply. I tried dumping the contents of mbuf as you have
> suggested.
> This is what I get:
>
> dump mbuf at 0x0x6c7620, phys=7f34d91eba28, buf_len=59488
> pkt_len=0, ol_flags=0, nb_segs=0, in_port=0
>
> and soon after that I get a segmentation fault. Do you have any idea on
> what could be causing it ?
>
> Regards
>
>
>
> On Fri, Mar 14, 2014 at 9:40 PM, Chris Wright wrote:
>
> > * sabu kurian (sabu2kurian at gmail.com) wrote:
> > > Hello friends,
> > >
> > > I'm trying to print the ether_type for a packet that I captured from a
> > port
> > > on my machine. Suppose 'm' holds the packet. 'm' is of type 'struct
> > > rte_mbuf'. Intels API reference for DPDK says 'ether_type' is of
> > uint16_t.
> > > I used the following code to retrieve ether_type.
> > >
> > > void * eth_type;
> > > struct ether_hdr *eth;
> > >
> > > eth = rte_pktmbuf_mtod(m, struct ether_hdr *);
> > > eth_type = ð->ether_type;
> > >
> > > printf("\n Type is %" PRIu16 , *((uint16_t *)eth_type));
> >
> > Looks ok, albeit slightly overly complicated.
> >
> > struct ether_hdr *eth;
> > uint16_t eth_type;
> >
> > eth = rte_pktmbuf_mtod(m, struct ether_hdr *);
> > eth_type = eth->ether_type;
> > printf("\n Type is %" PRIu16 , eth_type));
> >
> > This would remove all the extra casting. Perhaps the mbuf is the problem
> > here. And if so, the above snippet would segfault on eth->ether_type
> > showing you that mbuf is invalid.
> >
> > You could try to (above mtod):
> >
> > rte_pktmbuf_dump(m, sizeof(struct ether_hdr));
> >
> > as that will show key contents of mbuf and packet data (and do some
> > basic validation along the way).
> >
> > thanks,
> > -chris
> >
>
