[PATCH 12/17] nvme-tcp: control message handling for recvmsg()

[Hannes Reinecke <hare@suse.de>]

kTLS is sending TLS ALERT messages as control messages for recvmsg().
As we can't do anything sensible with it just abort the connection
and let the userspace agent to a re-negotiation.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
---
 drivers/nvme/host/tcp.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index d25695cf4e03..a3ac512fd1cc 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1362,6 +1362,11 @@ static int nvme_tcp_init_connection(struct nvme_tcp_queue *queue)
 {
 	struct nvme_tcp_icreq_pdu *icreq;
 	struct nvme_tcp_icresp_pdu *icresp;
+#ifdef CONFIG_NVME_TCP_TLS
+	char cbuf[CMSG_LEN(sizeof(char))] = {};
+	struct cmsghdr *cmsg;
+	unsigned char ctype;
+#endif
 	struct msghdr msg = {};
 	struct kvec iov;
 	bool ctrl_hdgst, ctrl_ddgst;
@@ -1399,11 +1404,27 @@ static int nvme_tcp_init_connection(struct nvme_tcp_queue *queue)
 	memset(&msg, 0, sizeof(msg));
 	iov.iov_base = icresp;
 	iov.iov_len = sizeof(*icresp);
+#ifdef CONFIG_NVME_TCP_TLS
+	msg.msg_control = cbuf;
+	msg.msg_controllen = sizeof(cbuf);
+#endif
 	ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
 			iov.iov_len, msg.msg_flags);
 	if (ret < 0)
 		goto free_icresp;
-
+#ifdef CONFIG_NVME_TCP_TLS
+	cmsg = (struct cmsghdr *)cbuf;
+	if (CMSG_OK(&msg, cmsg) &&
+	    cmsg->cmsg_level == SOL_TLS &&
+	    cmsg->cmsg_type == TLS_GET_RECORD_TYPE) {
+		ctype = *((unsigned char *)CMSG_DATA(cmsg));
+		if (ctype != TLS_RECORD_TYPE_DATA) {
+			pr_err("queue %d: unhandled TLS record %d\n",
+			       nvme_tcp_queue_id(queue), ctype);
+			return -ENOTCONN;
+		}
+	}
+#endif
 	ret = -EINVAL;
 	if (icresp->hdr.type != nvme_tcp_icresp) {
 		pr_err("queue %d: bad type returned %d\n",
-- 
2.35.3