Re: [dpdk-dev] [PATCH] llib/ibrte_net: workaround to avoid macro conflict

["Wu, Jingjing" <jingjing.wu@intel.com>]

Hi, Neil

To have rte_ip.h include netinet/in.h directly is also a choice.

But netinet/in.h contains a lot of extra stuff, and these may be useless some DPDK applications, such as classification.
rte_ip.h provides a more simplify way for the IP protocol layer.

-----Original Message-----
From: Neil Horman [mailto:nhorman@tuxdriver.com] 
Sent: Tuesday, September 30, 2014 9:10 PM
To: Wu, Jingjing
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH] llib/ibrte_net: workaround to avoid macro conflict

On Tue, Sep 30, 2014 at 10:49:08AM +0800, Jingjing Wu wrote:
> Macros such as IPPROTO_TCP, IPPROTO_UDP are already defined in <netinet/in.h>.
> If user's application includes <netinet/in.h> and rte_ip.h at the same 
> time, there will be conflict error.
> 
> This patch uses the way "#ifndef #endif" to avoid the conflict. 
> 
> Signed-off-by: Jingjing Wu <jingjing.wu@intel.com>
> ---
>  lib/librte_net/rte_ip.h | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h index 
> e3f65c1..2bcb479 100644
> --- a/lib/librte_net/rte_ip.h
> +++ b/lib/librte_net/rte_ip.h
> @@ -116,6 +116,8 @@ struct ipv4_hdr {
>  
>  #define	IPV4_HDR_OFFSET_UNITS	8
>  
> +#ifndef _NETINET_IN_H
> +#ifndef _NETINET_IN_H_
>  /* IPv4 protocols */
>  #define IPPROTO_IP         0  /**< dummy for IP */
>  #define IPPROTO_HOPOPTS    0  /**< IP6 hop-by-hop options */
> @@ -227,6 +229,9 @@ struct ipv4_hdr {
>  #define IPPROTO_RAW      255  /**< raw IP packet */
>  #define IPPROTO_MAX      256  /**< maximum protocol number */
>  
> +#endif /*_NETINET_IN_H_*/
> +#endif /*_NETINET_IN_H*/
> +
>  /*
>   * IPv4 address types
>   */
> --
> 1.8.1.4
> 
> 
Why define them at all?  Why not just have rte_ip.h include netinet/in.h directly?  Its a standard include file in a standard location for both bsd and linux IIRC.
Neil