cifs: fix sockaddr comparison in iface_cmp

iface_cmp used to simply do a memcmp of the two
provided struct sockaddrs. The comparison needs to do more
based on the address family. Similar logic was already
present in cifs_match_ipaddr. Doing something similar now.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/smb/client/cifsglob.h

@@ -970,43 +970,6 @@ release_iface(struct kref *ref)
 	kfree(iface);
 }
 
-/*
- * compare two interfaces a and b
- * return 0 if everything matches.
- * return 1 if a has higher link speed, or rdma capable, or rss capable
- * return -1 otherwise.
- */
-static inline int
-iface_cmp(struct cifs_server_iface *a, struct cifs_server_iface *b)
-{
-	int cmp_ret = 0;
-
-	WARN_ON(!a || !b);
-	if (a->speed == b->speed) {
-		if (a->rdma_capable == b->rdma_capable) {
-			if (a->rss_capable == b->rss_capable) {
-				cmp_ret = memcmp(&a->sockaddr, &b->sockaddr,
-						 sizeof(a->sockaddr));
-				if (!cmp_ret)
-					return 0;
-				else if (cmp_ret > 0)
-					return 1;
-				else
-					return -1;
-			} else if (a->rss_capable > b->rss_capable)
-				return 1;
-			else
-				return -1;
-		} else if (a->rdma_capable > b->rdma_capable)
-			return 1;
-		else
-			return -1;
-	} else if (a->speed > b->speed)
-		return 1;
-	else
-		return -1;
-}
-
 struct cifs_chan {
 	unsigned int in_reconnect : 1; /* if session setup in progress for this channel */
 	struct TCP_Server_Info *server;

fs/smb/client/cifsproto.h

@@ -87,6 +87,7 @@ extern int cifs_handle_standard(struct TCP_Server_Info *server,
 				struct mid_q_entry *mid);
 extern int smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx);
 extern int smb3_parse_opt(const char *options, const char *key, char **val);
+extern int cifs_ipaddr_cmp(struct sockaddr *srcaddr, struct sockaddr *rhs);
 extern bool cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs);
 extern int cifs_discard_remaining_data(struct TCP_Server_Info *server);
 extern int cifs_call_async(struct TCP_Server_Info *server,

fs/smb/client/connect.c

@@ -1288,6 +1288,56 @@ next_pdu:
 	module_put_and_kthread_exit(0);
 }
 
+int
+cifs_ipaddr_cmp(struct sockaddr *srcaddr, struct sockaddr *rhs)
+{
+	struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
+	struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
+	struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
+	struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
+
+	switch (srcaddr->sa_family) {
+	case AF_UNSPEC:
+		switch (rhs->sa_family) {
+		case AF_UNSPEC:
+			return 0;
+		case AF_INET:
+		case AF_INET6:
+			return 1;
+		default:
+			return -1;
+		}
+	case AF_INET: {
+		switch (rhs->sa_family) {
+		case AF_UNSPEC:
+			return -1;
+		case AF_INET:
+			return memcmp(saddr4, vaddr4,
+				      sizeof(struct sockaddr_in));
+		case AF_INET6:
+			return 1;
+		default:
+			return -1;
+		}
+	}
+	case AF_INET6: {
+		switch (rhs->sa_family) {
+		case AF_UNSPEC:
+		case AF_INET:
+			return -1;
+		case AF_INET6:
+			return memcmp(saddr6,
+				      vaddr6,
+				      sizeof(struct sockaddr_in6));
+		default:
+			return -1;
+		}
+	}
+	default:
+		return -1; /* don't expect to be here */
+	}
+}
+
 /*
  * Returns true if srcaddr isn't specified and rhs isn't specified, or
  * if srcaddr is specified and matches the IP address of the rhs argument

fs/smb/client/smb2ops.c

@@ -510,6 +510,43 @@ smb3_negotiate_rsize(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
 	return rsize;
 }
 
+/*
+ * compare two interfaces a and b
+ * return 0 if everything matches.
+ * return 1 if a is rdma capable, or rss capable, or has higher link speed
+ * return -1 otherwise.
+ */
+static int
+iface_cmp(struct cifs_server_iface *a, struct cifs_server_iface *b)
+{
+	int cmp_ret = 0;
+
+	WARN_ON(!a || !b);
+	if (a->rdma_capable == b->rdma_capable) {
+		if (a->rss_capable == b->rss_capable) {
+			if (a->speed == b->speed) {
+				cmp_ret = cifs_ipaddr_cmp((struct sockaddr *) &a->sockaddr,
+							  (struct sockaddr *) &b->sockaddr);
+				if (!cmp_ret)
+					return 0;
+				else if (cmp_ret > 0)
+					return 1;
+				else
+					return -1;
+			} else if (a->speed > b->speed)
+				return 1;
+			else
+				return -1;
+		} else if (a->rss_capable > b->rss_capable)
+			return 1;
+		else
+			return -1;
+	} else if (a->rdma_capable > b->rdma_capable)
+		return 1;
+	else
+		return -1;
+}
+
 static int
 parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
 			size_t buf_len, struct cifs_ses *ses, bool in_mount)