libexport.a: Refactor netgroup checking in client_check()

Clean up: refactor netgroup logic out of client_check() to make it
easier to introduce IPv6 support.

 +  Use preferred style of keeping #ifdef out of the middle of
    function definitions.  Squelch compiler warnings for "#ifndef
    HAVE_INNETGR" by using __attribute__((unused)).

 +  Use preferred style of not using curly braces around switch cases.

 +  Match style used for check_{fqdn,subnetwork}.

 +  Clarify comment documenting use of h_aliases

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/support/export/client.c b/support/export/client.c
index 419a4a7d930f6999e8a0f26dc397fce2b3d5f899..580012d9eaa38d2a45a9f8af4dd563ace3197315 100644 (file)
--- a/support/export/client.c
+++ b/support/export/client.c
@@ -370,6 +370,62 @@ check_subnetwork(const nfs_client *clp, const struct hostent *hp)
        return 0;
 }
 
+/*
+ * Check if @hp's hostname or aliases fall in a given netgroup.
+ * Return 1 if @hp represents a host in the netgroup, otherwise zero.
+ */
+#ifdef HAVE_INNETGR
+static int
+check_netgroup(const nfs_client *clp, const struct hostent *hp)
+{
+       const char *netgroup = clp->m_hostname + 1;
+       const char *hname = hp->h_name;
+       struct hostent *nhp = NULL;
+       struct sockaddr_in addr;
+       int match, i;
+       char *dot;
+
+       /* First, try to match the hostname without
+        * splitting off the domain */
+       if (innetgr(netgroup, hname, NULL, NULL))
+               return 1;
+
+       /* See if hname aliases listed in /etc/hosts or nis[+]
+        * match the requested netgroup */
+       for (i = 0; hp->h_aliases[i]; i++) {
+               if (innetgr(netgroup, hp->h_aliases[i], NULL, NULL))
+                       return 1;
+       }
+
+       /* If hname is ip address convert to FQDN */
+       if (inet_aton(hname, &addr.sin_addr) &&
+          (nhp = gethostbyaddr((const char *)&(addr.sin_addr),
+           sizeof(addr.sin_addr), AF_INET))) {
+               hname = nhp->h_name;
+               if (innetgr(netgroup, hname, NULL, NULL))
+                       return 1;
+       }
+
+       /* Okay, strip off the domain (if we have one) */
+       dot = strchr(hname, '.');
+       if (dot == NULL)
+               return 0;
+
+       *dot = '\0';
+       match = innetgr(netgroup, hname, NULL, NULL);
+       *dot = '.';
+
+       return match;
+}
+#else  /* !HAVE_INNETGR */
+static int
+check_netgroup(__attribute__((unused)) const nfs_client *clp,
+               __attribute__((unused)) const struct hostent *hp)
+{
+       return 0;
+}
+#endif /* !HAVE_INNETGR */
+
 /*
  * Match a host (given its hostent record) to a client record. This
  * is usually called from mountd.
@@ -396,46 +452,7 @@ client_check(nfs_client *clp, struct hostent *hp)
                }
                return 0;
        case MCL_NETGROUP:
-#ifdef HAVE_INNETGR
-               {
-                       char    *dot;
-                       int     match, i;
-                       struct hostent *nhp = NULL;
-                       struct sockaddr_in addr;
-
-                       /* First, try to match the hostname without
-                        * splitting off the domain */
-                       if (innetgr(cname+1, hname, NULL, NULL))
-                               return 1;
-
-                       /* try the aliases as well */
-                       for (i = 0; hp->h_aliases[i]; i++) {
-                               if (innetgr(cname+1, hp->h_aliases[i], NULL, NULL))
-                                       return 1;
-                       }
-
-                       /* If hname is ip address convert to FQDN */
-                       if (inet_aton(hname, &addr.sin_addr) &&
-                          (nhp = gethostbyaddr((const char *)&(addr.sin_addr),
-                           sizeof(addr.sin_addr), AF_INET))) {
-                               hname = (char *)nhp->h_name;
-                               if (innetgr(cname+1, hname, NULL, NULL))
-                                       return 1;
-                       }
-
-                       /* Okay, strip off the domain (if we have one) */
-                       if ((dot = strchr(hname, '.')) == NULL)
-                               return 0;
-
-                       *dot = '\0';
-                       match = innetgr(cname+1, hname, NULL, NULL);
-                       *dot = '.';
-
-                       return match;
-               }
-#else
-               return 0;
-#endif
+               return check_netgroup(clp, hp);
        case MCL_ANONYMOUS:
                return 1;
        case MCL_GSS: