Hi Marco, On Jun 23 13:41, Marco Atzeri wrote: > Hi, > the attached two test programs should perform exactly the same call > to getaddrinfo for 127.0.0.1 > > however on 32 bit > CYGWIN_NT-6.1-WOW64 1.7.30(0.272/5/3) 2014-05-23 10:36 i686 Cygwin > > 32 $ ./getaddrinfo_test-1_32 > 127.0.0.1 ai_addr > 02 00 00 00 7f 00 00 01 00 00 00 00 00 00 00 00 > > 32 $ ./getaddrinfo_test-2_32 > 127.0.0.1 ai_addr > 02 00 00 00 7f 00 00 01 00 00 00 00 00 00 00 00 > > while on 64 bit > CYGWIN_NT-6.1 1.7.30(0.272/5/3) 2014-05-23 10:36 x86_64 Cygwin > > 64 $ ./getaddrinfo_test-1_64 > 127.0.0.1 ai_addr > 02 00 00 00 7f 00 00 01 00 00 00 00 00 00 00 00 > > 64 $ ./getaddrinfo_test-2_64 > getaddrinfo: Non-recoverable failure in name resolution > > > Am I missing something ? > The second way is currently used on postgresql in several places, > but it seems to fail only for "127.0.0.1"
I don't know why this only fails for "127.0.0.1". But this is clearly a problem in the 64 bit Cygwin DLL. What happens is that the field ai_addrlen is defined as socklen_t in POSIX, but as size_t in the W32 API. On 64 bit, socklen_t is 4 bytes while size_t is 8 bytes. Setting all the hintp members manually (in contrast to calloc'ing it or memset'ing it to 0) leaves the 4 upper bytes of the ai_addrlen untouched. This in turn leads to a high probability that ai_addrlen has an invalid value when entering Winsock's getsockopt. I'm really surprised this hasn't been hit before. I'm going to fix that in Cygwin by setting the upper 4 bytes of ai_addrlen to 0 explicitely. For the time being, you might prepend memset (&hintp, 0, sizeof hintp); to the code, prior to setting the elements manually. Thanks for the testcase. Much appreciated, Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat
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