X-Git-Url: https://git.decadent.org.uk/gitweb/?a=blobdiff_plain;f=utils%2Fstatd%2Fhostname.c;h=746ecc7c57b5f6aba93484f4293ab2cc39fa9028;hb=9a5293a10551c03b4fb976503dd24da569fcadb3;hp=7571b6f44a864318ef28425e58b07fcfea154efb;hpb=d6ea66438d89c7708a10e464013491655f5361b0;p=nfs-utils.git

diff --git a/utils/statd/hostname.c b/utils/statd/hostname.c
index 7571b6f..746ecc7 100644
--- a/utils/statd/hostname.c
+++ b/utils/statd/hostname.c
@@ -126,6 +126,148 @@ get_addrinfo(const char *hostname, const struct addrinfo *hint)
 	return NULL;
 }
 
+#ifdef HAVE_GETNAMEINFO
+static _Bool
+get_nameinfo(const struct sockaddr *sap, const socklen_t salen,
+		/*@out@*/ char *buf, const socklen_t buflen)
+{
+	int error;
+
+	error = getnameinfo(sap, salen, buf, buflen, NULL, 0, NI_NAMEREQD);
+	if (error != 0) {
+		xlog(D_GENERAL, "%s: failed to resolve address: %s",
+				__func__, gai_strerror(error));
+		return false;
+	}
+
+	return true;
+}
+#else	/* !HAVE_GETNAMEINFO */
+static _Bool
+get_nameinfo(const struct sockaddr *sap,
+		__attribute__ ((unused)) const socklen_t salen,
+		/*@out@*/ char *buf, socklen_t buflen)
+{
+	struct sockaddr_in *sin = (struct sockaddr_in *)(char *)sap;
+	struct hostent *hp;
+
+	if (sin->sin_family != AF_INET) {
+		xlog(D_GENERAL, "%s: unknown address family: %d",
+				sin->sin_family);
+		return false;
+	}
+
+	hp = gethostbyaddr((const char *)&(sin->sin_addr.s_addr),
+				sizeof(struct in_addr), AF_INET);
+	if (hp == NULL) {
+		xlog(D_GENERAL, "%s: failed to resolve address: %m", __func__);
+		return false;
+	}
+
+	strncpy(buf, hp->h_name, (size_t)buflen);
+	return true;
+}
+#endif	/* !HAVE_GETNAMEINFO */
+
+/**
+ * statd_canonical_name - choose file name for monitor record files
+ * @hostname: C string containing hostname or presentation address
+ *
+ * Returns a '\0'-terminated ASCII string containing a fully qualified
+ * canonical hostname, or NULL if @hostname does not have a reverse
+ * mapping.  Caller must free the result with free(3).
+ *
+ * Incoming hostnames are looked up to determine the canonical hostname,
+ * and incoming presentation addresses are converted to canonical
+ * hostnames.
+ *
+ * We won't monitor peers that don't have a reverse map.  The canonical
+ * name gives us a key for our monitor list.
+ */
+__attribute_malloc__
+char *
+statd_canonical_name(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)
+			/* OK to use presentation address,
+			 * if no reverse map exists */
+			return strdup(hostname);
+		return strdup(buf);
+	}
+
+	/* @hostname was a hostname */
+	hint.ai_flags = AI_CANONNAME;
+	ai = get_addrinfo(hostname, &hint);
+	if (ai == NULL)
+		return NULL;
+	strcpy(buf, ai->ai_canonname);
+	freeaddrinfo(ai);
+
+	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
@@ -142,11 +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) {
@@ -154,10 +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;
 
@@ -177,7 +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;
 }