From bc8594e7c388c8a5cfb9516a0980877cb1321d32 Mon Sep 17 00:00:00 2001 From: Greg Hudson Date: Thu, 23 Jun 2011 04:13:38 +0000 Subject: [PATCH] Work around glibc getaddrinfo PTR lookups In krb5_sname_to_principal(), we always do a forward canonicalization using getaddrinfo() with AI_CANONNAME set. Then, we do a reverse canonicalization with getnameinfo() if rdns isn't set to false in libdefaults. Current glibc (tested with eglibc 2.11.1) has the arguably buggy behavior of doing PTR lookups in getaddrinfo() to get the canonical name, if hints.ai_family is set to something other than AF_UNSPEC. This behavior defeats the ability to turn off rdns. Work around this behavior by using AF_UNSPEC in krb5_sname_to_principal() from the start, instead of starting with AF_INET and falling back. Specify AI_ADDRCONFIG to avoid AAAA lookups on hosts with no IPv6 addresses. ticket: 6922 git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@24977 dc483132-0cff-0310-8789-dd5450dbe970 --- src/lib/krb5/os/sn2princ.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/src/lib/krb5/os/sn2princ.c b/src/lib/krb5/os/sn2princ.c index b5a2d2611..46eab6c24 100644 --- a/src/lib/krb5/os/sn2princ.c +++ b/src/lib/krb5/os/sn2princ.c @@ -105,19 +105,12 @@ krb5_sname_to_principal(krb5_context context, const char *hostname, const char * hostnames associated. */ memset(&hints, 0, sizeof(hints)); - hints.ai_family = AF_INET; - hints.ai_flags = AI_CANONNAME; - try_getaddrinfo_again: + hints.ai_flags = AI_CANONNAME | AI_ADDRCONFIG; err = getaddrinfo(hostname, 0, &hints, &ai); if (err) { #ifdef DEBUG_REFERRALS printf("sname_to_princ: probably punting due to bad hostname of %s\n",hostname); #endif - if (hints.ai_family == AF_INET) { - /* Just in case it's an IPv6-only name. */ - hints.ai_family = 0; - goto try_getaddrinfo_again; - } return KRB5_ERR_BAD_HOSTNAME; } remote_host = strdup(ai->ai_canonname ? ai->ai_canonname : hostname); -- 2.26.2