Commit a1c5dd83 authored by Hannes Reinecke's avatar Hannes Reinecke Committed by Keith Busch
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nvmet-tcp: control messages for recvmsg() 



kTLS requires control messages for recvmsg() to relay any out-of-band
TLS messages (eg TLS alerts) to the caller.

Signed-off-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarSagi Grimberg <sagi@grimberg.me>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
parent 675b453e

drivers/nvme/target/tcp.c

+80 −13
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <net/sock.h>

#include <net/tcp.h>

#include <net/tls.h>

#include <net/tls_prot.h>

#include <net/handshake.h>

#include <linux/inet.h>

#include <linux/llist.h>
@@ -118,6 +119,7 @@ struct nvmet_tcp_cmd { 
	u32				pdu_len;

	u32				pdu_recv;

	int				sg_idx;

	char				recv_cbuf[CMSG_LEN(sizeof(char))];

	struct msghdr			recv_msg;

	struct bio_vec			*iov;

	u32				flags;
@@ -1121,20 +1123,65 @@ static inline bool nvmet_tcp_pdu_valid(u8 type) 
	return false;

}



static int nvmet_tcp_tls_record_ok(struct nvmet_tcp_queue *queue,

		struct msghdr *msg, char *cbuf)

{

	struct cmsghdr *cmsg = (struct cmsghdr *)cbuf;

	u8 ctype, level, description;

	int ret = 0;



	ctype = tls_get_record_type(queue->sock->sk, cmsg);

	switch (ctype) {

	case 0:

		break;

	case TLS_RECORD_TYPE_DATA:

		break;

	case TLS_RECORD_TYPE_ALERT:

		tls_alert_recv(queue->sock->sk, msg, &level, &description);

		if (level == TLS_ALERT_LEVEL_FATAL) {

			pr_err("queue %d: TLS Alert desc %u\n",

			       queue->idx, description);

			ret = -ENOTCONN;

		} else {

			pr_warn("queue %d: TLS Alert desc %u\n",

			       queue->idx, description);

			ret = -EAGAIN;

		}

		break;

	default:

		/* discard this record type */

		pr_err("queue %d: TLS record %d unhandled\n",

		       queue->idx, ctype);

		ret = -EAGAIN;

		break;

	}

	return ret;

}



static int nvmet_tcp_try_recv_pdu(struct nvmet_tcp_queue *queue)

{

	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;

	int len;

	int len, ret;

	struct kvec iov;

	char cbuf[CMSG_LEN(sizeof(char))] = {};

	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };



recv:

	iov.iov_base = (void *)&queue->pdu + queue->offset;

	iov.iov_len = queue->left;

	if (queue->tls_pskid) {

		msg.msg_control = cbuf;

		msg.msg_controllen = sizeof(cbuf);

	}

	len = kernel_recvmsg(queue->sock, &msg, &iov, 1,

			iov.iov_len, msg.msg_flags);

	if (unlikely(len < 0))

		return len;

	if (queue->tls_pskid) {

		ret = nvmet_tcp_tls_record_ok(queue, &msg, cbuf);

		if (ret < 0)

			return ret;

	}



	queue->offset += len;

	queue->left -= len;
@@ -1187,16 +1234,22 @@ static void nvmet_tcp_prep_recv_ddgst(struct nvmet_tcp_cmd *cmd) 
static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)

{

	struct nvmet_tcp_cmd  *cmd = queue->cmd;

	int ret;

	int len, ret;



	while (msg_data_left(&cmd->recv_msg)) {

		ret = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,

		len = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,

			cmd->recv_msg.msg_flags);

		if (ret <= 0)

		if (len <= 0)

			return len;

		if (queue->tls_pskid) {

			ret = nvmet_tcp_tls_record_ok(cmd->queue,

					&cmd->recv_msg, cmd->recv_cbuf);

			if (ret < 0)

				return ret;

		}



		cmd->pdu_recv += ret;

		cmd->rbytes_done += ret;

		cmd->pdu_recv += len;

		cmd->rbytes_done += len;

	}



	if (queue->data_digest) {
@@ -1214,20 +1267,30 @@ static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue) 
static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)

{

	struct nvmet_tcp_cmd *cmd = queue->cmd;

	int ret;

	int ret, len;

	char cbuf[CMSG_LEN(sizeof(char))] = {};

	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };

	struct kvec iov = {

		.iov_base = (void *)&cmd->recv_ddgst + queue->offset,

		.iov_len = queue->left

	};



	ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,

	if (queue->tls_pskid) {

		msg.msg_control = cbuf;

		msg.msg_controllen = sizeof(cbuf);

	}

	len = kernel_recvmsg(queue->sock, &msg, &iov, 1,

			iov.iov_len, msg.msg_flags);

	if (unlikely(ret < 0))

	if (unlikely(len < 0))

		return len;

	if (queue->tls_pskid) {

		ret = nvmet_tcp_tls_record_ok(queue, &msg, cbuf);

		if (ret < 0)

			return ret;

	}



	queue->offset += ret;

	queue->left -= ret;

	queue->offset += len;

	queue->left -= len;

	if (queue->left)

		return -EAGAIN;
@@ -1407,6 +1470,10 @@ static int nvmet_tcp_alloc_cmd(struct nvmet_tcp_queue *queue, 
	if (!c->r2t_pdu)

		goto out_free_data;



	if (queue->state == NVMET_TCP_Q_TLS_HANDSHAKE) {

		c->recv_msg.msg_control = c->recv_cbuf;

		c->recv_msg.msg_controllen = sizeof(c->recv_cbuf);

	}

	c->recv_msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;



	list_add_tail(&c->entry, &queue->free_list);