From 4bc0dcae0b64eccd63f753d05b505b0becdcb2c8 Mon Sep 17 00:00:00 2001
From: Peter Wagner <tripolar@gmx.at>
Date: Tue, 19 Feb 2019 19:50:03 +0100
Subject: [PATCH 1/2] don't free ai->ai_canonname

---
 support/export/hostname.c | 58 ++++++++-------------------------------
 utils/mountd/auth.c       | 16 +++++------
 2 files changed, 20 insertions(+), 54 deletions(-)

diff --git a/support/export/hostname.c b/support/export/hostname.c
index 5c4c824..96c5449 100644
--- a/support/export/hostname.c
+++ b/support/export/hostname.c
@@ -264,9 +264,9 @@ host_canonname(const struct sockaddr *sap)
  * Reverse and forward lookups are performed to ensure the address has
  * matching forward and reverse mappings.
  *
- * Returns addrinfo structure with just the provided address with
- * ai_canonname filled in. If there is a problem with resolution or
- * the resolved records don't match up properly then it returns NULL
+ * Returns addrinfo structure with just the provided address. If there
+ * is a problem with resolution or the resolved records don't match up
+ * properly then returns NULL.
  *
  * Caller must free the returned structure with freeaddrinfo(3).
  */
@@ -277,13 +277,15 @@ host_reliable_addrinfo(const struct sockaddr *sap)
 	struct addrinfo *ai, *a;
 	char *hostname;
 
+	ai = NULL;
 	hostname = host_canonname(sap);
 	if (hostname == NULL)
-		return NULL;
+		goto out;
 
 	ai = host_addrinfo(hostname);
+	free(hostname);
 	if (!ai)
-		goto out_free_hostname;
+		goto out;
 
 	/* make sure there's a matching address in the list */
 	for (a = ai; a; a = a->ai_next)
@@ -291,22 +293,15 @@ host_reliable_addrinfo(const struct sockaddr *sap)
 			break;
 
 	freeaddrinfo(ai);
+	ai = NULL;
 	if (!a)
-		goto out_free_hostname;
+		goto out;
 
 	/* get addrinfo with just the original address */
 	ai = host_numeric_addrinfo(sap);
-	if (!ai)
-		goto out_free_hostname;
 
-	/* and populate its ai_canonname field */
-	free(ai->ai_canonname);
-	ai->ai_canonname = hostname;
+out:
 	return ai;
-
-out_free_hostname:
-	free(hostname);
-	return NULL;
 }
 
 /**
@@ -323,7 +318,6 @@ host_numeric_addrinfo(const struct sockaddr *sap)
 {
 	socklen_t salen = nfs_sockaddr_length(sap);
 	char buf[INET6_ADDRSTRLEN];
-	struct addrinfo *ai;
 	int error;
 
 	if (salen == 0) {
@@ -348,21 +342,7 @@ host_numeric_addrinfo(const struct sockaddr *sap)
 		return NULL;
 	}
 
-	ai = host_pton(buf);
-
-	/*
-	 * getaddrinfo(AI_NUMERICHOST) never fills in ai_canonname
-	 */
-	if (ai != NULL) {
-		free(ai->ai_canonname);		/* just in case */
-		ai->ai_canonname = strdup(buf);
-		if (ai->ai_canonname == NULL) {
-			freeaddrinfo(ai);
-			ai = NULL;
-		}
-	}
-
-	return ai;
+	return host_pton(buf);
 }
 #else	/* !HAVE_GETNAMEINFO */
 __attribute__((__malloc__))
@@ -372,7 +352,6 @@ host_numeric_addrinfo(const struct sockaddr *sap)
 	const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 	const struct in_addr *addr = &sin->sin_addr;
 	char buf[INET_ADDRSTRLEN];
-	struct addrinfo *ai;
 
 	if (sap->sa_family != AF_INET)
 		return NULL;
@@ -382,19 +361,6 @@ host_numeric_addrinfo(const struct sockaddr *sap)
 					(socklen_t)sizeof(buf)) == NULL)
 		return NULL;
 
-	ai = host_pton(buf);
-
-	/*
-	 * getaddrinfo(AI_NUMERICHOST) never fills in ai_canonname
-	 */
-	if (ai != NULL) {
-		ai->ai_canonname = strdup(buf);
-		if (ai->ai_canonname == NULL) {
-			freeaddrinfo(ai);
-			ai = NULL;
-		}
-	}
-
-	return ai;
+	return host_pton(buf);
 }
 #endif	/* !HAVE_GETNAMEINFO */
diff --git a/utils/mountd/auth.c b/utils/mountd/auth.c
index 8299256..cb4848c 100644
--- a/utils/mountd/auth.c
+++ b/utils/mountd/auth.c
@@ -261,40 +261,40 @@ auth_authenticate(const char *what, const struct sockaddr *caller,
 		*p = '\0';
 	}
 
+	host_ntop(caller, buf, sizeof(buf));
 	switch (error) {
 	case bad_path:
 		xlog(L_WARNING, "bad path in %s request from %s: \"%s\"",
-		     what, host_ntop(caller, buf, sizeof(buf)), path);
+		     what, buf, path);
 		break;
 
 	case unknown_host:
 		xlog(L_WARNING, "refused %s request from %s for %s (%s): unmatched host",
-		     what, host_ntop(caller, buf, sizeof(buf)), path, epath);
+		     what, buf, path, epath);
 		break;
 
 	case no_entry:
 		xlog(L_WARNING, "refused %s request from %s for %s (%s): no export entry",
-		     what, ai->ai_canonname, path, epath);
+		     what, buf, path, epath);
 		break;
 
 	case not_exported:
 		xlog(L_WARNING, "refused %s request from %s for %s (%s): not exported",
-		     what, ai->ai_canonname, path, epath);
+		     what, buf, path, epath);
 		break;
 
 	case illegal_port:
 		xlog(L_WARNING, "refused %s request from %s for %s (%s): illegal port %u",
-		     what, ai->ai_canonname, path, epath, nfs_get_port(caller));
+		     what, buf, path, epath, nfs_get_port(caller));
 		break;
 
 	case success:
 		xlog(L_NOTICE, "authenticated %s request from %s:%u for %s (%s)",
-		     what, ai->ai_canonname, nfs_get_port(caller), path, epath);
+		     what, buf, nfs_get_port(caller), path, epath);
 		break;
 	default:
 		xlog(L_NOTICE, "%s request from %s:%u for %s (%s) gave %d",
-		     what, ai->ai_canonname, nfs_get_port(caller),
-			path, epath, error);
+		     what, buf, nfs_get_port(caller), path, epath, error);
 	}
 
 	freeaddrinfo(ai);
-- 
2.20.1