Re: A few issues on MIPS and now on ARMEL

[Rich Felker <dalias@aerifal.cx>]

On Thu, Nov 15, 2012 at 06:37:25PM -0500, Rich Felker wrote:
> On Fri, Nov 16, 2012 at 12:21:11AM +0200, Paul Schutte wrote:
> > Hi guys,
> > 
> > I am now hitting a similar problem on armel.
> > 
> > I am cross-compiling "dnsmasq"
> > 
> > Glibc strace:
> > 
> > ---snip---
> > socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP) = 5
> > fcntl64(5, F_GETFL)                     = 0x2 (flags O_RDWR)
> > fcntl64(5, F_SETFL, O_RDWR|O_NONBLOCK)  = 0
> > setsockopt(5, SOL_IP, IP_MTU_DISCOVER, [0], 4) = 0
> > setsockopt(5, SOL_IP, IP_PKTINFO, [1], 4) = 0
> > setsockopt(5, SOL_SOCKET, SO_BROADCAST, [1], 4) = 0
> > setsockopt(5, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
> > 
> > 
> > Musl strace:
> > 
> > socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP) = 5
> > fcntl64(5, F_GETFL)                     = 0x2 (flags O_RDWR)
> > fcntl64(5, F_SETFL, O_RDWR|O_NONBLOCK|O_LARGEFILE) = 0
> > setsockopt(5, SOL_IP, IP_MTU_DISCOVER, [0], 4) = 0
> > setsockopt(5, SOL_IP, IP_PKTINFO, [1], 4) = 0
> > setsockopt(5, SOL_SOCKET, SO_BROADCAST, [1], 4) = 0
> > setsockopt(5, SOL_SOCKET, *0xf /* SO_??? */*, [1], 4) = -1 ENOPROTOOPT
> > (Protocol not available)
> 
> Thanks for the report. I'll check and see if ARM has unusual
> definitions we're missing.

This doesn't seem to be ARM-specific. Linux has reserved a number for
SO_REUSEPORT, but it's not implemented in the kernel it seems, and
musl is providing the value, presumably causing the app to use it and
think it works. I'm guessing I should just remove it, but it might be
possible/preferable to make setsockopt and getsockopt remap it to
SO_REUSEADDR internally. Ideas anyone?

Rich