[dpdk-dev] symbol conflicts between netinet/in.h, arpa/inet.h, and rte_ip.h

[Niraj Sharma (nirajsha)]

I also noticed this problem. It is a serious one. I would like it solved.

-- Niraj Sharma

Principal Eng.
Cisco System, Inc.


On 7/24/14 12:59 AM, "Matthew Hall" <mhall at mhcomputing.net> wrote:

>Hello,
>
>I ran into some weird symbol conflicts between system netinet/in.h and
>DPDK 
>rte_ip.h. They have a lot of duplicated definitions for stuff like
>IPPROTO_IP 
>and so on. This breaks when you want to use inet_pton from arpa/inet.h,
>because it includes netinet/in.h to define struct in_addr.
>
>Thus with all the conflicts it's impossible to use a DPDK IP struct
>instead of 
>all the system's sockaddr stuff, to store a value from the system copy of
>inet_pton. This would be a common operation if, for example, you want to
>configure all the IP addresses on your box from a JSON file, which is
>what I 
>was doing.
>
>The DPDK kludged around it internally by using a file called
>cmdline_parse_ipaddr.c with private copies of these functions. But it in
>my 
>opinion very unwisely marked all of the functions as static except for
>cmdline_parse_ipaddr, which only works on the DPDK's proprietary argument
>handling, and not with anything the user might have which is a different
>format.
>
>So, it would be a big help for users if the macros in librte_net files
>would 
>check if the symbols already existed, or if they had subheader files
>available 
>to grab only non conflicting symbols, or if they would make a proper .h
>and 
>factor all the inet_pton and inet_ntop inside the cmdline lib into a
>place 
>where users can access them. It would also be a help if they had a less
>ugly 
>equivalent to struct sockaddr, which let you work with IP addresses a bit
>more 
>easily, such as something like this:
>
>struct ip4_addr {
>    uint32_t addr;
>};
>
>typedef struct ip4_addr ip4_addr;
>
>struct ip6_addr {
>    uint8_t addr[16];
>};
>
>typedef struct ip6_addr ip6_addr;
>
>struct ip_addr {
>    uint8_t family;
>    uint8_t prefix;
>    union {
>        struct ip4_addr ipv4;
>        struct ip6_addr ipv6;
>    };
>};
>
>I had to create a bunch of duplicate code to handle it in my project,
>since 
>the DPDK marked its copies of all these functions as "secret" and didn't
>make 
>a .h for them. If any of it is useful I am happy to donate it, although I
>don't think I've got quite enough experience with this specifc part of
>the 
>DPDK to code it up all by myself.
>
>Thanks,
>Matthew.