lockd: Teach nlm_cmp_addr() to support AF_INET6 addresses

Update the nlm_cmp_addr() helper to support AF_INET6 as well as AF_INET
addresses.  New version takes two "struct sockaddr *" arguments instead of
"struct sockaddr_in *" arguments.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/lockd/clntlock.c

@@ -166,7 +166,8 @@ __be32 nlmclnt_grant(const struct sockaddr_in *addr, const struct nlm_lock *lock
 		 */
 		if (fl_blocked->fl_u.nfs_fl.owner->pid != lock->svid)
 			continue;
-		if (!nlm_cmp_addr(nlm_addr_in(block->b_host), addr))
+		if (!nlm_cmp_addr(nlm_addr(block->b_host),
+					(struct sockaddr *)addr))
 			continue;
 		if (nfs_compare_fh(NFS_FH(fl_blocked->fl_file->f_path.dentry->d_inode) ,fh) != 0)
 			continue;

fs/lockd/host.c

@@ -116,7 +116,7 @@ static struct nlm_host *nlm_lookup_host(int server,
 	 */
 	chain = &nlm_hosts[hash];
 	hlist_for_each_entry(host, pos, chain, h_hash) {
-		if (!nlm_cmp_addr(nlm_addr_in(host), sin))
+		if (!nlm_cmp_addr(nlm_addr(host), (struct sockaddr *)sin))
 			continue;
 
 		/* See if we have an NSM handle for this client */
@@ -129,7 +129,7 @@ static struct nlm_host *nlm_lookup_host(int server,
 			continue;
 		if (host->h_server != server)
 			continue;
-		if (!nlm_cmp_addr(nlm_srcaddr_in(host), ssin))
+		if (!nlm_cmp_addr(nlm_srcaddr(host), (struct sockaddr *)ssin))
 			continue;
 
 		/* Move to head of hash chain. */
@@ -551,7 +551,7 @@ __nsm_find(const struct sockaddr_in *sin,
 			if (strlen(pos->sm_name) != hostname_len
 			 || memcmp(pos->sm_name, hostname, hostname_len))
 				continue;
-		} else if (!nlm_cmp_addr(nsm_addr_in(pos), sin))
+		} else if (!nlm_cmp_addr(nsm_addr(pos), (struct sockaddr *)sin))
 			continue;
 		atomic_inc(&pos->sm_count);
 		kfree(nsm);

fs/lockd/svcsubs.c

@@ -418,7 +418,7 @@ EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb);
 static int
 nlmsvc_match_ip(void *datap, struct nlm_host *host)
 {
-	return nlm_cmp_addr(nlm_srcaddr_in(host), datap);
+	return nlm_cmp_addr(nlm_srcaddr(host), datap);
 }
 
 /**

include/linux/lockd/lockd.h

@@ -12,6 +12,8 @@
 #ifdef __KERNEL__
 
 #include <linux/in.h>
+#include <linux/in6.h>
+#include <net/ipv6.h>
 #include <linux/fs.h>
 #include <linux/kref.h>
 #include <linux/utsname.h>
@@ -272,13 +274,39 @@ static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
 	return file->f_file->f_path.dentry->d_inode;
 }
 
+static inline int __nlm_cmp_addr4(const struct sockaddr *sap1,
+				  const struct sockaddr *sap2)
+{
+	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sap1;
+	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sap2;
+	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
+}
+
+static inline int __nlm_cmp_addr6(const struct sockaddr *sap1,
+				  const struct sockaddr *sap2)
+{
+	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sap1;
+	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sap2;
+	return ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr);
+}
+
 /*
- * Compare two host addresses (needs modifying for ipv6)
+ * Compare two host addresses
+ *
+ * Return TRUE if the addresses are the same; otherwise FALSE.
  */
-static inline int nlm_cmp_addr(const struct sockaddr_in *sin1,
-			       const struct sockaddr_in *sin2)
+static inline int nlm_cmp_addr(const struct sockaddr *sap1,
+			       const struct sockaddr *sap2)
 {
-	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
+	if (sap1->sa_family == sap2->sa_family) {
+		switch (sap1->sa_family) {
+		case AF_INET:
+			return __nlm_cmp_addr4(sap1, sap2);
+		case AF_INET6:
+			return __nlm_cmp_addr6(sap1, sap2);
+		}
+	}
+	return 0;
 }
 
 /*