Date: Mon, 5 Apr 2004 19:34:24 +0200 From: Pierre Beyssac <pb@FreeBSD.org> To: audit@FreeBSD.org Cc: green@FreeBSD.org Subject: fix for getipnodebyname(3) Message-ID: <20040405173424.GA2440@bofh.enst.fr> In-Reply-To: <20040217161920.GB712@straylight.m.ringlet.net> References: <20040217161920.GB712@straylight.m.ringlet.net>
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getipnodebyname(3) as it stands in FreeBSD 4 and 5 has a problem
with nameserver timeouts or misconfiguration.
Symptom: getipnodebyname(3) lookups in unreachable/unconfigured
zones return h_errno=HOST_NOT_FOUND instead of h_errno=TRY_AGAIN.
It causes email to bounce at least with sendmail, which is quite
annoying.
Unless someone objects to it, I'd like to commit the following fix
to current later today. Since FreeBSD 4 is impacted too, the patch
will have to be adapted and MFC'd some day.
The only potential problem I see with my patch is that it accesses
h_errno, which is possibly not thread-safe. Could someone please
shed some light on this for me?
Pierre
--- name6.c.old Wed Feb 25 23:27:17 2004
+++ name6.c Mon Apr 5 14:19:31 2004
@@ -1565,7 +1565,8 @@
continue;
hp = _hpcopy(&hpbuf, errp);
hp0 = _hpmerge(hp0, hp, errp);
- }
+ } else
+ *errp = h_errno;
}
if (hp0 != NULL) {
free(buf);
@@ -1604,7 +1605,8 @@
continue;
hp = _hpcopy(&hpbuf, errp);
hp0 = _hpmerge(hp0, hp, errp);
- }
+ } else
+ *errp = h_errno;
}
if (hp0 != NULL) {
free(buf);
@@ -1677,7 +1679,8 @@
continue;
hp = _hpcopy(&hpbuf, errp);
hp0 = _hpmerge(hp0, hp, errp);
- }
+ } else
+ *errp = h_errno;
}
if (hp0 != NULL) {
free(buf);
@@ -1739,7 +1742,12 @@
rtl = &rtl4;
#endif
*(struct hostent **)rval = _res_search_multi(name, rtl, errp);
- return (*(struct hostent **)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND;
+ if (*(struct hostent **)rval != NULL)
+ return NS_SUCCESS;
+ else if (*errp == TRY_AGAIN)
+ return NS_TRYAGAIN;
+ else
+ return NS_NOTFOUND;
}
static int
--
Pierre Beyssac pb@freebsd.org
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