On Thu, Jun 30, 2022 at 12:40 AM Nathan Hartman <hartman.nat...@gmail.com> wrote:
> On Wed, Jun 29, 2022 at 12:23 PM Xiang Xiao <xiaoxiang781...@gmail.com> > wrote: > > > > On Wed, Jun 29, 2022 at 4:44 AM Nathan Hartman <hartman.nat...@gmail.com > > > > wrote: > > > > > On Tue, Jun 28, 2022 at 4:05 PM Nathan Hartman < > hartman.nat...@gmail.com> > > > wrote: > > > > > > > > I have a program that builds under Linux, BSD, and macOS which > > > > includes the net/if_arp.h header. > > > > > > > > This header does not seem to exist under NuttX. > > > > > > > > It is included for the ARPHRD_ETHER define (and possibly other > things). > > > > > > > > I see that under NuttX, this is defined in net/arp.h, rather than > > > net/if_arp.h. > > > > > > > > Is net/if_arp.h supposed to be a standard header? I cannot seem to > > > > find any meaningful information about it. > > > > > > > > > > > If no standard defines it, it's better to follow other OS(especially, > other > > POSIX compliant)'s practices. > > > Hmm... well the net/if_arp.h header seems to exist on Linux and macOS > (BSD), so maybe we need to do something similar. > > I still can't seem to find much information about this header, so for > now I added a special case: if __NuttX__ is defined then I #include > <nuttx/net/arp.h>. Otherwise I include <net/if_arp.h>. It builds, but > I do not know if the code that uses the ARPHRD_ETHER define is working > correctly because I haven't tested it yet. > > The code is trying to get the MAC address of a Ethernet interface > using ioctl SIOCGIFHWADDR on a temporary socket. In the returned > struct ifreq, it checks if ifr_hwaddr.sa_family == ARPHRD_ETHER to > ensure it is a Ethernet MAC and not a different type of interface. > > here is NuttX's implementation: https://github.com/apache/incubator-nuttx/blob/master/net/netdev/netdev_ioctl.c#L914-L949 If the implementation isn't fully compatible with other OS, I normally prefer to update NuttX's one. > Maybe there is a better way to do this in NuttX but I prefer to leave > the application code unchanged if possible. > > More below... > > > > > Also, do we lack the defines IFF_LOOPBACK, IFF_UP, IFF_BROADCAST, and > > > IFF_MULTICAST? I can't find them anywhere, except in comments. > > > > > > For example, a grep for IFF_LOOPBACK shows it in the comments for > > > getifaddrs(): > > > > > > [[[ > > > * Depending on whether the bit IFF_BROADCAST or IFF_POINTOPOINT is > > > * set in ifa_flags (only one can be set at a time), either > > > * ifa_broadaddr will contain the broadcast address associated with > > > * ifa_addr (if applicable for the address family) or ifa_dstaddr > > > * will contain the destination address of the point-to-point > > > * interface. > > > ]]] > > > > > > but no such define exists in NuttX. > > > > > > > We just added the related code a couple weeks ago. My teammate will > > upstream the change soon. > > > That is very good news! I'll be looking out for it when it lands. Feel > free to ping me for review on GitHub. > > It's here: https://github.com/apache/incubator-nuttx/pull/6543 > Thanks for the reply. > > Cheers, > Nathan >
