Commit dea034b9 authored by Chuck Lever's avatar Chuck Lever Committed by Trond Myklebust
Browse files

SUNRPC: Capture CMSG metadata on client-side receive 



kTLS sockets use CMSG to report decryption errors and the need
for session re-keying.

For RPC-with-TLS, an "application data" message contains a ULP
payload, and that is passed along to the RPC client. An "alert"
message triggers connection reset. Everything else is discarded.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 0d3ca07f

net/sunrpc/xprtsock.c

+47 −2
Original line number Diff line number Diff line
@@ -47,6 +47,8 @@ 
#include <net/checksum.h>

#include <net/udp.h>

#include <net/tcp.h>

#include <net/tls.h>



#include <linux/bvec.h>

#include <linux/highmem.h>

#include <linux/uio.h>
@@ -347,13 +349,56 @@ xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp) 
	return want;

}



static int

xs_sock_process_cmsg(struct socket *sock, struct msghdr *msg,

		     struct cmsghdr *cmsg, int ret)

{

	if (cmsg->cmsg_level == SOL_TLS &&

	    cmsg->cmsg_type == TLS_GET_RECORD_TYPE) {

		u8 content_type = *((u8 *)CMSG_DATA(cmsg));



		switch (content_type) {

		case TLS_RECORD_TYPE_DATA:

			/* TLS sets EOR at the end of each application data

			 * record, even though there might be more frames

			 * waiting to be decrypted.

			 */

			msg->msg_flags &= ~MSG_EOR;

			break;

		case TLS_RECORD_TYPE_ALERT:

			ret = -ENOTCONN;

			break;

		default:

			ret = -EAGAIN;

		}

	}

	return ret;

}



static int

xs_sock_recv_cmsg(struct socket *sock, struct msghdr *msg, int flags)

{

	union {

		struct cmsghdr	cmsg;

		u8		buf[CMSG_SPACE(sizeof(u8))];

	} u;

	int ret;



	msg->msg_control = &u;

	msg->msg_controllen = sizeof(u);

	ret = sock_recvmsg(sock, msg, flags);

	if (msg->msg_controllen != sizeof(u))

		ret = xs_sock_process_cmsg(sock, msg, &u.cmsg, ret);

	return ret;

}



static ssize_t

xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)

{

	ssize_t ret;

	if (seek != 0)

		iov_iter_advance(&msg->msg_iter, seek);

	ret = sock_recvmsg(sock, msg, flags);

	ret = xs_sock_recv_cmsg(sock, msg, flags);

	return ret > 0 ? ret + seek : ret;

}
@@ -379,7 +424,7 @@ xs_read_discard(struct socket *sock, struct msghdr *msg, int flags, 
		size_t count)

{

	iov_iter_discard(&msg->msg_iter, ITER_DEST, count);

	return sock_recvmsg(sock, msg, flags);

	return xs_sock_recv_cmsg(sock, msg, flags);

}



#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE