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

[Neil Horman <nhorman@tuxdriver.com>]

On Thu, Oct 09, 2014 at 05:20:31AM +0000, Wu, Jingjing wrote:
> 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.
> 
Not sure what the relevance there is.  The definitions you want are
standardized, theres no need for the dpdk to re-invent that wheel.  Get them
from the system include file.  The fact that extra macros are available in
netinet.h is neither relevant or true (as you can't really say for certain what
an application will need).

Neil

> -----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
> 
>