From 1bb84a09ff58d1314826945db2f3f1f63015e263 Mon Sep 17 00:00:00 2001
From: Chuck Lever <chuck.lever@oracle.com>
Date: Tue, 24 Aug 2010 07:13:54 -0400
Subject: [PATCH] libexport: Fix IP address check in check_netgroup()
Neil Brown reports that recent changes to replace
gethostby{addr,name}(3) with get{addr,info}name(3) may have
inadvertently broken netgroup support.
There used to be a gethostbyaddr(3) call in the third paragraph in
check_netgroup(). The reason for that gethostbyaddr(3) call was that
the first innetgr(3) call has already confirmed that hname is not a
member of the netgroup. We also need to confirm that, if hname
happens to be an IP address, the hostname bound to that IP address is
not a member of the netgroup, either.
Fix this by restoring appropriate address to hostname mapping of hname
before retrying the innetgr(3) call.
See http://marc.info/?l=linux-nfs&m=128084830214653&w=2 .
Introduced by commit 0509d3428f523776ddd9d6e9fa318587d3ec7d84.
Reviewed-by: Neil Brown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steve Dickson <steved@redhat.com>
---
support/export/client.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/support/export/client.c b/support/export/client.c
index b1a3a09..21001ce 100644
--- a/support/export/client.c
+++ b/support/export/client.c
@@ -490,14 +490,19 @@ static int
check_netgroup(const nfs_client *clp, const struct addrinfo *ai)
{
const char *netgroup = clp->m_hostname + 1;
- const char *hname = ai->ai_canonname;
struct addrinfo *tmp = NULL;
struct hostent *hp;
+ char *dot, *hname;
int i, match;
- char *dot;
match = 0;
+ hname = strdup(ai->ai_canonname);
+ if (hname == NULL) {
+ xlog(D_GENERAL, "%s: no memory for strdup", __func__);
+ goto out;
+ }
+
/* First, try to match the hostname without
* splitting off the domain */
if (innetgr(netgroup, hname, NULL, NULL)) {
@@ -516,13 +521,21 @@ check_netgroup(const nfs_client *clp, const struct addrinfo *ai)
}
}
- /* If hname is ip address convert to FQDN */
+ /* If hname happens to be an IP address, convert it
+ * to a the canonical DNS name bound to this address. */
tmp = host_pton(hname);
if (tmp != NULL) {
+ char *cname = host_canonname(tmp->ai_addr);
freeaddrinfo(tmp);
- if (innetgr(netgroup, hname, NULL, NULL)) {
- match = 1;
- goto out;
+
+ /* The resulting FQDN may be in our netgroup. */
+ if (cname != NULL) {
+ free(hname);
+ hname = cname;
+ if (innetgr(netgroup, hname, NULL, NULL)) {
+ match = 1;
+ goto out;
+ }
}
}
@@ -533,9 +546,9 @@ check_netgroup(const nfs_client *clp, const struct addrinfo *ai)
*dot = '\0';
match = innetgr(netgroup, hname, NULL, NULL);
- *dot = '.';
out:
+ free(hname);
return match;
}
#else /* !HAVE_INNETGR */
--
2.39.5