NFS: Simplify logic to compare socket addresses in client.c

Callback requests from IPv4 servers are now always guaranteed to be
AF_INET, and never mapped IPv4 AF_INET6 addresses.  Both
nfs_match_client() and nfs_find_client() can now share the same
address comparison logic, so fold them together.

We can also dispense with of most of the conditional compilation
in here.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 52 insertions, 64 deletions

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 574158ae2398..855daac0f246 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -224,38 +224,6 @@ void nfs_put_client(struct nfs_client *clp)
 }
 
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
-static const struct in6_addr *nfs_map_ipv4_addr(const struct sockaddr *sa, struct in6_addr *addr_mapped)
-{
-        switch (sa->sa_family) {
-                default:
-                        return NULL;
-                case AF_INET6:
-                        return &((const struct sockaddr_in6 *)sa)->sin6_addr;
-                        break;
-                case AF_INET:
-                        ipv6_addr_set_v4mapped(((const struct sockaddr_in *)sa)->sin_addr.s_addr,
-                                        addr_mapped);
-                        return addr_mapped;
-        }
-}
-
-static int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
-                const struct sockaddr *sa2)
-{
-        const struct in6_addr *addr1;
-        const struct in6_addr *addr2;
-        struct in6_addr addr1_mapped;
-        struct in6_addr addr2_mapped;
-
-        addr1 = nfs_map_ipv4_addr(sa1, &addr1_mapped);
-        if (likely(addr1 != NULL)) {
-                addr2 = nfs_map_ipv4_addr(sa2, &addr2_mapped);
-                if (likely(addr2 != NULL))
-                        return ipv6_addr_equal(addr1, addr2);
-        }
-        return 0;
-}
-
 /*
  * Test if two ip6 socket addresses refer to the same socket by
  * comparing relevant fields. The padding bytes specifically, are not
@@ -267,38 +235,21 @@ static int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
  *
  * The caller should ensure both socket addresses are AF_INET6.
  */
-static int nfs_sockaddr_cmp_ip6(const struct sockaddr *sa1,
-                                const struct sockaddr *sa2)
+static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
+                                      const struct sockaddr *sa2)
 {
-        const struct sockaddr_in6 *saddr1 = (const struct sockaddr_in6 *)sa1;
-        const struct sockaddr_in6 *saddr2 = (const struct sockaddr_in6 *)sa2;
+        const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
+        const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
 
-        if (!ipv6_addr_equal(&saddr1->sin6_addr,
-                             &saddr1->sin6_addr))
+        if (ipv6_addr_scope(&sin1->sin6_addr) == IPV6_ADDR_SCOPE_LINKLOCAL &&
+            sin1->sin6_scope_id != sin2->sin6_scope_id)
                 return 0;
-        if (ipv6_addr_scope(&saddr1->sin6_addr) == IPV6_ADDR_SCOPE_LINKLOCAL &&
-            saddr1->sin6_scope_id != saddr2->sin6_scope_id)
-                return 0;
-        return saddr1->sin6_port == saddr2->sin6_port;
-}
-#else
-static int nfs_sockaddr_match_ipaddr4(const struct sockaddr_in *sa1,
-                                 const struct sockaddr_in *sa2)
-{
-        return sa1->sin_addr.s_addr == sa2->sin_addr.s_addr;
-}
 
-static int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
-                                 const struct sockaddr *sa2)
-{
-        if (unlikely(sa1->sa_family != AF_INET || sa2->sa_family != AF_INET))
-                return 0;
-        return nfs_sockaddr_match_ipaddr4((const struct sockaddr_in *)sa1,
-                        (const struct sockaddr_in *)sa2);
+        return ipv6_addr_equal(&sin1->sin6_addr, &sin1->sin6_addr);
 }
-
-static int nfs_sockaddr_cmp_ip6(const struct sockaddr * sa1,
-                                const struct sockaddr * sa2)
+#else   /* !defined(CONFIG_IPV6) && !defined(CONFIG_IPV6_MODULE) */
+static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
+                                      const struct sockaddr *sa2)
 {
         return 0;
 }
@@ -311,20 +262,57 @@ static int nfs_sockaddr_cmp_ip6(const struct sockaddr * sa1,
  *
  * The caller should ensure both socket addresses are AF_INET.
  */
+static int nfs_sockaddr_match_ipaddr4(const struct sockaddr *sa1,
+                                      const struct sockaddr *sa2)
+{
+        const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
+        const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
+
+        return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
+}
+
+static int nfs_sockaddr_cmp_ip6(const struct sockaddr *sa1,
+                                const struct sockaddr *sa2)
+{
+        const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
+        const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
+
+        return nfs_sockaddr_match_ipaddr6(sa1, sa2) &&
+                (sin1->sin6_port == sin2->sin6_port);
+}
+
 static int nfs_sockaddr_cmp_ip4(const struct sockaddr *sa1,
                                 const struct sockaddr *sa2)
 {
-        const struct sockaddr_in *saddr1 = (const struct sockaddr_in *)sa1;
-        const struct sockaddr_in *saddr2 = (const struct sockaddr_in *)sa2;
+        const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
+        const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
 
-        if (saddr1->sin_addr.s_addr != saddr2->sin_addr.s_addr)
+        return nfs_sockaddr_match_ipaddr4(sa1, sa2) &&
+                (sin1->sin_port == sin2->sin_port);
+}
+
+/*
+ * Test if two socket addresses represent the same actual socket,
+ * by comparing (only) relevant fields, excluding the port number.
+ */
+static int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
+                                     const struct sockaddr *sa2)
+{
+        if (sa1->sa_family != sa2->sa_family)
                 return 0;
-        return saddr1->sin_port == saddr2->sin_port;
+
+        switch (sa1->sa_family) {
+        case AF_INET:
+                return nfs_sockaddr_match_ipaddr4(sa1, sa2);
+        case AF_INET6:
+                return nfs_sockaddr_match_ipaddr6(sa1, sa2);
+        }
+        return 0;
 }
 
 /*
  * Test if two socket addresses represent the same actual socket,
- * by comparing (only) relevant fields.
+ * by comparing (only) relevant fields, including the port number.
  */
 static int nfs_sockaddr_cmp(const struct sockaddr *sa1,
                             const struct sockaddr *sa2)