Date: Mon, 22 Jan 2018 02:33:12 +0300 From: Yuri Pankov <yuripv@icloud.com> To: Li-Wen Hsu <lwhsu@freebsd.org>, freebsd-hackers@freebsd.org Subject: Re: Calling getaddrinfo(3) in 32-bit binary on 64-bit host Message-ID: <8c6dc5b5-7640-61fc-b687-08efd1e621ee@icloud.com> In-Reply-To: <CAKBkRUx14r%2B%2BZ-n64SNDd4uu=hoJv-KaXxeyUGM7f%2BDS2Ha%2BmQ@mail.gmail.com> References: <CAKBkRUx14r%2B%2BZ-n64SNDd4uu=hoJv-KaXxeyUGM7f%2BDS2Ha%2BmQ@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Jan 22, 2018 at 05:14:59AM +0800, Li-Wen Hsu wrote: > Hi all, > > Recently I found a strange case: calling getaddrinfo(3) cannot resolve IPv6 > address in 32-bit binary on 64-bit host. > It happens on vanilla installed 11.1-R and also on r327788 snapshot build. > > For a program like this: > https://gist.github.com/lwhsu/1288aa5be90b9e7da934a3e2bfc55aa3 > > It works fine when compiled as a 32-bit binary and run on a 32-bit host. > As expected, It is also works fine when compiled as a 64-bit binary and run > on a 64-bit host > > However, when taking the 32-bit binary and run on a 64 bit system (with > /usr/lib32 installed), > getaddrinfo(3) just returns: "Non-recoverable failure in name resolution" Apparently, it goes through addrconfig() down to getifaddrs() returning bogus data for IPv6 addresses. This most likely has to with SALIGN being incorrect for 32-bit binary trying to parse route messages from 64-bit kernel. I'm not sure about proper fix here, but changing SALIGN to be 7 (that is, "sizeof(long) - 1" on amd64 platform) makes your test case return correct data.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?8c6dc5b5-7640-61fc-b687-08efd1e621ee>