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>

1 files changed, 37 insertions, 0 deletions

diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index 6e3be58cfe49..8bceb54ab061 100644
--- a/fs/smb/client/smb2ops.c
+++ b/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)