statd: Introduce statd version of matchhostname()

[nfs-utils.git] / utils / statd / hostname.c

diff --git a/utils/statd/hostname.c b/utils/statd/hostname.c
new file mode 100644 (file)
index 0000000..3d10d6f
--- /dev/null
+++ b/utils/statd/hostname.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright 2009 Oracle.  All rights reserved.
+ *
+ * This file is part of nfs-utils.
+ *
+ * nfs-utils is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * nfs-utils is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with nfs-utils.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * NSM for Linux.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include <strings.h>
+#include <netdb.h>
+
+#include "sockaddr.h"
+#include "statd.h"
+#include "xlog.h"
+
+/*
+ * Look up the hostname; report exceptional errors.  Caller must
+ * call freeaddrinfo(3) if a valid addrinfo is returned.
+ */
+__attribute_malloc__
+static struct addrinfo *
+get_addrinfo(const char *hostname, const struct addrinfo *hint)
+{
+       struct addrinfo *ai = NULL;
+       int error;
+
+       error = getaddrinfo(hostname, NULL, hint, &ai);
+       switch (error) {
+       case 0:
+               return ai;
+       case EAI_NONAME:
+               break;
+       default:
+               xlog(D_GENERAL, "%s: failed to resolve host %s: %s",
+                               __func__, hostname, gai_strerror(error));
+       }
+
+       return NULL;
+}
+
+/**
+ * statd_matchhostname - check if two hostnames are equivalent
+ * @hostname1: C string containing hostname
+ * @hostname2: C string containing hostname
+ *
+ * Returns true if the hostnames are the same, the hostnames resolve
+ * to the same canonical name, or the hostnames resolve to at least
+ * one address that is the same.  False is returned if the hostnames
+ * do not match in any of these ways, if either hostname contains
+ * wildcard characters, if either hostname is a netgroup name, or
+ * if an error occurs.
+ */
+_Bool
+statd_matchhostname(const char *hostname1, const char *hostname2)
+{
+       struct addrinfo *ai1, *ai2, *results1 = NULL, *results2 = NULL;
+       struct addrinfo hint = {
+               .ai_family      = AF_UNSPEC,
+               .ai_flags       = AI_CANONNAME,
+               .ai_protocol    = (int)IPPROTO_UDP,
+       };
+       _Bool result = false;
+
+       if (strcasecmp(hostname1, hostname2) == 0) {
+               result = true;
+               goto out;
+       }
+
+       results1 = get_addrinfo(hostname1, &hint);
+       if (results1 == NULL)
+               goto out;
+       results2 = get_addrinfo(hostname2, &hint);
+       if (results2 == NULL)
+               goto out;
+
+       if (strcasecmp(results1->ai_canonname, results2->ai_canonname) == 0) {
+               result = true;
+               goto out;
+       }
+
+       for (ai1 = results1; ai1 != NULL; ai1 = ai1->ai_next)
+               for (ai2 = results2; ai2 != NULL; ai2 = ai2->ai_next)
+                       if (nfs_compare_sockaddr(ai1->ai_addr, ai2->ai_addr)) {
+                               result = true;
+                               break;
+                       }
+
+out:
+       freeaddrinfo(results2);
+       freeaddrinfo(results1);
+
+       xlog(D_CALL, "%s: hostnames %s", __func__,
+                       (result ? "matched" : "did not match"));
+       return result;
+}