statd: statd_matchhostname() doesn't handle localhost properly

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

diff --git a/utils/statd/hostname.c b/utils/statd/hostname.c
index 616a3cbf45e2668ea57efe69c5aacf6995f80cd5..746ecc7c57b5f6aba93484f4293ab2cc39fa9028 100644 (file)
--- a/utils/statd/hostname.c
+++ b/utils/statd/hostname.c
@@ -225,6 +225,49 @@ statd_canonical_name(const char *hostname)
        return strdup(buf);
 }
 
+/*
+ * Take care to perform an explicit reverse lookup on presentation
+ * addresses.  Otherwise we don't get a real canonical name or a
+ * complete list of addresses.
+ *
+ * Returns an addrinfo list that has ai_canonname filled in, or
+ * NULL if some error occurs.  Caller must free the returned
+ * list with freeaddrinfo(3).
+ */
+__attribute_malloc__
+static struct addrinfo *
+statd_canonical_list(const char *hostname)
+{
+       struct addrinfo hint = {
+#ifdef IPV6_SUPPORTED
+               .ai_family      = AF_UNSPEC,
+#else  /* !IPV6_SUPPORTED */
+               .ai_family      = AF_INET,
+#endif /* !IPV6_SUPPORTED */
+               .ai_flags       = AI_NUMERICHOST,
+               .ai_protocol    = (int)IPPROTO_UDP,
+       };
+       char buf[NI_MAXHOST];
+       struct addrinfo *ai;
+
+       ai = get_addrinfo(hostname, &hint);
+       if (ai != NULL) {
+               /* @hostname was a presentation address */
+               _Bool result;
+               result = get_nameinfo(ai->ai_addr, ai->ai_addrlen,
+                                       buf, (socklen_t)sizeof(buf));
+               freeaddrinfo(ai);
+               if (result)
+                       goto out;
+       }
+       /* @hostname was a hostname or had no reverse mapping */
+       strcpy(buf, hostname);
+
+out:
+       hint.ai_flags = AI_CANONNAME;
+       return get_addrinfo(buf, &hint);
+}
+
 /**
  * statd_matchhostname - check if two hostnames are equivalent
  * @hostname1: C string containing hostname
@@ -241,11 +284,6 @@ _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) {
@@ -253,10 +291,10 @@ statd_matchhostname(const char *hostname1, const char *hostname2)
                goto out;
        }
 
-       results1 = get_addrinfo(hostname1, &hint);
+       results1 = statd_canonical_list(hostname1);
        if (results1 == NULL)
                goto out;
-       results2 = get_addrinfo(hostname2, &hint);
+       results2 = statd_canonical_list(hostname2);
        if (results2 == NULL)
                goto out;
 
@@ -276,7 +314,8 @@ out:
        freeaddrinfo(results2);
        freeaddrinfo(results1);
 
-       xlog(D_CALL, "%s: hostnames %s", __func__,
+       xlog(D_CALL, "%s: hostnames %s and %s %s", __func__,
+                       hostname1, hostname2,
                        (result ? "matched" : "did not match"));
        return result;
 }