mountd: Replace "struct hostent" with "struct addrinfo"

struct hostent can store either IPv4 or IPv6 addresses, but it can't
store both address families concurrently for the same host.  Neither
can hostent deal with parts of socket addresses that are outside of
the sin{,6}_addr field.

Replace the use of "struct hostent" everywhere in libexport.a, mountd,
and exportfs with "struct addrinfo".  This is a large change, but
there are so many strong dependencies on struct hostent that this
can't easily be broken into smaller pieces.

One benefit of this change is that hostent_dup() is no longer
required, since the results of getaddrinfo(3) are already dynamically
allocated.

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

1 files changed, 32 insertions, 14 deletions

diff --git a/support/export/export.c b/support/export/export.c
index 3e4da69..919a244 100644
--- a/support/export/export.c
+++ b/support/export/export.c
@@ -24,9 +24,11 @@ static int export_hash(char *);
 
 static void	export_init(nfs_export *exp, nfs_client *clp,
 					struct exportent *nep);
-static int	export_check(nfs_export *, struct hostent *, char *);
+static int	export_check(const nfs_export *exp, const struct addrinfo *ai,
+				const char *path);
 static nfs_export *
-		export_allowed_internal(struct hostent *hp, char *path);
+		export_allowed_internal(const struct addrinfo *ai,
+				const char *path);
 
 static void
 export_free(nfs_export *exp)
@@ -117,8 +119,8 @@ export_init(nfs_export *exp, nfs_client *clp, struct exportent *nep)
  * original hostname from /etc/exports, while the in-core client struct
  * gets the newly found FQDN.
  */
-nfs_export *
-export_dup(nfs_export *exp, struct hostent *hp)
+static nfs_export *
+export_dup(nfs_export *exp, const struct addrinfo *ai)
 {
 	nfs_export		*new;
 	nfs_client		*clp;
@@ -128,7 +130,7 @@ export_dup(nfs_export *exp, struct hostent *hp)
 	dupexportent(&new->m_export, &exp->m_export);
 	if (exp->m_export.e_hostname)
 		new->m_export.e_hostname = xstrdup(exp->m_export.e_hostname);
-	clp = client_dup(exp->m_client, hp);
+	clp = client_dup(exp->m_client, ai);
 	if (clp == NULL) {
 		export_free(new);
 		return NULL;
@@ -176,19 +178,27 @@ export_add(nfs_export *exp)
 	}
 }
 
+/**
+ * export_find - find or create a suitable nfs_export for @ai and @path
+ * @ai: pointer to addrinfo for client
+ * @path: '\0'-terminated ASCII string containing export path
+ *
+ * Returns a pointer to nfs_export data matching @ai and @path,
+ * or NULL if an error occurs.
+ */
 nfs_export *
-export_find(struct hostent *hp, char *path)
+export_find(const struct addrinfo *ai, const char *path)
 {
 	nfs_export	*exp;
 	int		i;
 
 	for (i = 0; i < MCL_MAXTYPES; i++) {
 		for (exp = exportlist[i].p_head; exp; exp = exp->m_next) {
-			if (!export_check(exp, hp, path))
+			if (!export_check(exp, ai, path))
 				continue;
 			if (exp->m_client->m_type == MCL_FQDN)
 				return exp;
-			return export_dup(exp, hp);
+			return export_dup(exp, ai);
 		}
 	}
 
@@ -196,7 +206,7 @@ export_find(struct hostent *hp, char *path)
 }
 
 static nfs_export *
-export_allowed_internal (struct hostent *hp, char *path)
+export_allowed_internal(const struct addrinfo *ai, const char *path)
 {
 	nfs_export	*exp;
 	int		i;
@@ -204,7 +214,7 @@ export_allowed_internal (struct hostent *hp, char *path)
 	for (i = 0; i < MCL_MAXTYPES; i++) {
 		for (exp = exportlist[i].p_head; exp; exp = exp->m_next) {
 			if (!exp->m_mayexport ||
-			    !export_check(exp, hp, path))
+			    !export_check(exp, ai, path))
 				continue;
 			return exp;
 		}
@@ -213,8 +223,16 @@ export_allowed_internal (struct hostent *hp, char *path)
 	return NULL;
 }
 
+/**
+ * export_allowed - determine if this export is allowed
+ * @ai: pointer to addrinfo for client
+ * @path: '\0'-terminated ASCII string containing export path
+ *
+ * Returns a pointer to nfs_export data matching @ai and @path,
+ * or NULL if the export is not allowed.
+ */
 nfs_export *
-export_allowed(struct hostent *hp, char *path)
+export_allowed(const struct addrinfo *ai, const char *path)
 {
 	nfs_export		*exp;
 	char			epath[MAXPATHLEN+1];
@@ -227,7 +245,7 @@ export_allowed(struct hostent *hp, char *path)
 
 	/* Try the longest matching exported pathname. */
 	while (1) {
-		exp = export_allowed_internal (hp, epath);
+		exp = export_allowed_internal(ai, epath);
 		if (exp)
 			return exp;
 		/* We have to treat the root, "/", specially. */
@@ -268,12 +286,12 @@ export_lookup(char *hname, char *path, int canonical)
 }
 
 static int
-export_check(nfs_export *exp, struct hostent *hp, char *path)
+export_check(const nfs_export *exp, const struct addrinfo *ai, const char *path)
 {
 	if (strcmp(path, exp->m_export.e_path))
 		return 0;
 
-	return client_check(exp->m_client, hp);
+	return client_check(exp->m_client, ai);
 }
 
 /**