Re: [PATCH 11/18] nvme-tcp: control message handling for recvmsg()

Sagi Grimberg
2023-03-22T11:33:09Z

> 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.

Is this a problem if we do end up adding read_sock to tls?
Although I do see that the tls code does manage this in the
sk_buff control buffer, so I assume there is access to this info.

CC'ing Boris here as well.

>
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> ---
> drivers/nvme/host/tcp.c | 68 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 68 insertions(+)
>
> diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
> index 007d457cacf9..e0fc98ac9e05 100644
> --- a/drivers/nvme/host/tcp.c
> +++ b/drivers/nvme/host/tcp.c
> @@ -13,6 +13,7 @@
> #include <linux/nvme-keyring.h>
> #include <net/sock.h>
> #include <net/tcp.h>
> +#include <net/tls.h>
> #include <net/handshake.h>
> #include <linux/blk-mq.h>
> #include <crypto/hash.h>
> @@ -727,7 +728,12 @@ static int nvme_tcp_recv_pdu(struct nvme_tcp_queue *queue, bool pending)
> {
> struct nvme_tcp_hdr *hdr;
> size_t rcv_len = queue->pdu_remaining;
> + char cbuf[CMSG_LEN(sizeof(char))] = {};
> + struct cmsghdr *cmsg;
> + unsigned char ctype;
> struct msghdr msg = {
> + .msg_control = cbuf,
> + .msg_controllen = sizeof(cbuf),
> .msg_flags = pending ? 0 : MSG_DONTWAIT,
> };
> struct kvec iov = {
> @@ -743,6 +749,18 @@ static int nvme_tcp_recv_pdu(struct nvme_tcp_queue *queue, bool pending)
> iov.iov_len, msg.msg_flags);
> if (ret <= 0)
> return ret;
> + 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) {
> + dev_err(queue->ctrl->ctrl.device,
> + "queue %d unhandled TLS record %d\n",
> + nvme_tcp_queue_id(queue), ctype);
> + return -ENOTCONN;
> + }
> + }
>
> rcv_len = ret;
> queue->pdu_remaining -= rcv_len;
> @@ -793,6 +811,9 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue)
> struct request *rq =
> nvme_cid_to_rq(nvme_tcp_tagset(queue), pdu->command_id);
> struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
> + char cbuf[CMSG_LEN(sizeof(char))];
> + struct cmsghdr *cmsg;
> + unsigned char ctype;
>
> if (nvme_tcp_recv_state(queue) != NVME_TCP_RECV_DATA)
> return 0;
> @@ -824,6 +845,8 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue)
> /* we can read only from what is left in this bio */
> memset(&msg, 0, sizeof(msg));
> msg.msg_iter = req->iter;
> + msg.msg_control = cbuf;
> + msg.msg_controllen = sizeof(cbuf);
>
> ret = sock_recvmsg(queue->sock, &msg, 0);
> if (ret <= 0) {
> @@ -832,6 +855,18 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue)
> nvme_tcp_queue_id(queue), rq->tag);
> return ret;
> }
> + 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) {
> + dev_err(queue->ctrl->ctrl.device,
> + "queue %d unhandled TLS record %d\n",
> + nvme_tcp_queue_id(queue), ctype);
> + return -ENOTCONN;
> + }
> + }
>
> queue->data_remaining -= ret;
> if (queue->data_remaining)
> @@ -861,7 +896,12 @@ static int nvme_tcp_recv_ddgst(struct nvme_tcp_queue *queue)
> char *ddgst = (char *)&queue->recv_ddgst;
> size_t recv_len = queue->ddgst_remaining;
> off_t off = NVME_TCP_DIGEST_LENGTH - queue->ddgst_remaining;
> + char cbuf[CMSG_LEN(sizeof(char))] = {};
> + struct cmsghdr *cmsg;
> + unsigned char ctype;
> struct msghdr msg = {
> + .msg_control = cbuf,
> + .msg_controllen = sizeof(cbuf),
> .msg_flags = 0,
> };
> struct kvec iov = {
> @@ -877,6 +917,18 @@ static int nvme_tcp_recv_ddgst(struct nvme_tcp_queue *queue)
> msg.msg_flags);
> if (ret <= 0)
> return ret;
> + 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) {
> + dev_err(queue->ctrl->ctrl.device,
> + "queue %d unhandled TLS record %d\n",
> + nvme_tcp_queue_id(queue), ctype);
> + return -ENOTCONN;
> + }
> + }
>
> recv_len = ret;
> queue->ddgst_remaining -= recv_len;
> @@ -1372,6 +1424,9 @@ static int nvme_tcp_init_connection(struct nvme_tcp_queue *queue)
> {
> struct nvme_tcp_icreq_pdu *icreq;
> struct nvme_tcp_icresp_pdu *icresp;
> + char cbuf[CMSG_LEN(sizeof(char))] = {};
> + struct cmsghdr *cmsg;
> + unsigned char ctype;
> struct msghdr msg = {};
> struct kvec iov;
> bool ctrl_hdgst, ctrl_ddgst;
> @@ -1409,10 +1464,23 @@ 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);
> + msg.msg_control = cbuf;
> + msg.msg_controllen = sizeof(cbuf);
> ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
> iov.iov_len, msg.msg_flags);
> if (ret < 0)
> goto free_icresp;
> + 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;
> + }
> + }
>
> ret = -EINVAL;
> if (icresp->hdr.type != nvme_tcp_icresp) {