freebsd-dev/sys/rpc/krpc.h
Rick Macklem ab0c29af05 Add TLS support to the kernel RPC.
An internet draft titled "Towards Remote Procedure Call Encryption By Default"
describes how TLS is to be used for Sun RPC, with NFS as an intended use case.
This patch adds client and server support for this to the kernel RPC,
using KERN_TLS and upcalls to daemons for the handshake, peer reset and
other non-application data record cases.

The upcalls to the daemons use three fields to uniquely identify the
TCP connection. They are the time.tv_sec, time.tv_usec of the connection
establshment, plus a 64bit sequence number. The time fields avoid problems
with re-use of the sequence number after a daemon restart.
For the server side, once a Null RPC with AUTH_TLS is received, kernel
reception on the socket is blocked and an upcall to the rpctlssd(8) daemon
is done to perform the TLS handshake.  Upon completion, the completion
status of the handshake is stored in xp_tls as flag bits and the reply to
the Null RPC is sent.
For the client, if CLSET_TLS has been set, a new TCP connection will
send the Null RPC with AUTH_TLS to initiate the handshake.  The client
kernel RPC code will then block kernel I/O on the socket and do an upcall
to the rpctlscd(8) daemon to perform the handshake.
If the upcall is successful, ct_rcvstate will be maintained to indicate
if/when an upcall is being done.

If non-application data records are received, the code does an upcall to
the appropriate daemon, which will do a SSL_read() of 0 length to handle
the record(s).

When the socket is being shut down, upcalls are done to the daemons, so
that they can perform SSL_shutdown() calls to perform the "peer reset".

The rpctlssd(8) and rpctlscd(8) daemons require a patched version of the
openssl library and, as such, will not be committed to head at this time.

Although the changes done by this patch are fairly numerous, there should
be no semantics change to the kernel RPC at this time.
A future commit to the NFS code will optionally enable use of TLS for NFS.
2020-08-22 03:57:55 +00:00

133 lines
5.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2009, Sun Microsystems, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - Neither the name of Sun Microsystems, Inc. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _RPC_KRPC_H_
#define _RPC_KRPC_H_
#ifdef _KERNEL
/*
* Definitions now shared between client and server RPC for backchannels.
*/
#define MCALL_MSG_SIZE 24
void clnt_bck_svccall(void *, struct mbuf *, uint32_t);
enum clnt_stat clnt_bck_call(CLIENT *, struct rpc_callextra *, rpcproc_t,
struct mbuf *, struct mbuf **, struct timeval, SVCXPRT *);
struct mbuf *_rpc_copym_into_ext_pgs(struct mbuf *, int);
/*
* A pending RPC request which awaits a reply. Requests which have
* received their reply will have cr_xid set to zero and cr_mrep to
* the mbuf chain of the reply.
*/
struct ct_request {
TAILQ_ENTRY(ct_request) cr_link;
uint32_t cr_xid; /* XID of request */
struct mbuf *cr_mrep; /* reply received by upcall */
int cr_error; /* any error from upcall */
char cr_verf[MAX_AUTH_BYTES]; /* reply verf */
};
TAILQ_HEAD(ct_request_list, ct_request);
struct rc_data {
struct mtx rc_lock;
struct sockaddr_storage rc_addr; /* server address */
struct netconfig* rc_nconf; /* network type */
rpcprog_t rc_prog; /* program number */
rpcvers_t rc_vers; /* version number */
size_t rc_sendsz;
size_t rc_recvsz;
struct timeval rc_timeout;
struct timeval rc_retry;
int rc_retries;
int rc_privport;
char *rc_waitchan;
int rc_intr;
int rc_connecting;
int rc_closed;
struct ucred *rc_ucred;
CLIENT* rc_client; /* underlying RPC client */
struct rpc_err rc_err;
void *rc_backchannel;
bool rc_tls; /* Enable TLS on connection */
};
/* Bits for ct_rcvstate. */
#define RPCRCVSTATE_NORMAL 0x01 /* Normal reception. */
#define RPCRCVSTATE_NONAPPDATA 0x02 /* Reception of a non-application record. */
#define RPCRCVSTATE_TLSHANDSHAKE 0x04 /* Reception blocked for TLS handshake. */
#define RPCRCVSTATE_UPCALLNEEDED 0x08 /* Upcall to rpctlscd needed. */
#define RPCRCVSTATE_UPCALLINPROG 0x10 /* Upcall to rpctlscd in progress. */
#define RPCRCVSTATE_SOUPCALLNEEDED 0x20 /* Socket upcall needed. */
#define RPCRCVSTATE_UPCALLTHREAD 0x40 /* Upcall kthread running. */
struct ct_data {
struct mtx ct_lock;
int ct_threads; /* number of threads in clnt_vc_call */
bool_t ct_closing; /* TRUE if we are closing */
bool_t ct_closed; /* TRUE if we are closed */
struct socket *ct_socket; /* connection socket */
bool_t ct_closeit; /* close it on destroy */
struct timeval ct_wait; /* wait interval in milliseconds */
struct sockaddr_storage ct_addr; /* remote addr */
struct rpc_err ct_error;
uint32_t ct_xid;
char ct_mcallc[MCALL_MSG_SIZE]; /* marshalled callmsg */
size_t ct_mpos; /* pos after marshal */
const char *ct_waitchan;
int ct_waitflag;
struct mbuf *ct_record; /* current reply record */
size_t ct_record_resid; /* how much left of reply to read */
bool_t ct_record_eor; /* true if reading last fragment */
struct ct_request_list ct_pending;
int ct_upcallrefs; /* Ref cnt of upcalls in prog. */
SVCXPRT *ct_backchannelxprt; /* xprt for backchannel */
uint64_t ct_sslsec; /* RPC-over-TLS connection. */
uint64_t ct_sslusec;
uint64_t ct_sslrefno;
uint32_t ct_rcvstate; /* Handle receiving for TLS upcalls */
struct mbuf *ct_raw; /* Raw mbufs recv'd */
};
struct cf_conn { /* kept in xprt->xp_p1 for actual connection */
enum xprt_stat strm_stat;
struct mbuf *mpending; /* unparsed data read from the socket */
struct mbuf *mreq; /* current record being built from mpending */
uint32_t resid; /* number of bytes needed for fragment */
bool_t eor; /* reading last fragment of current record */
};
#endif /* _KERNEL */
#endif /* _RPC_KRPC_H_ */