SUNRPC: Add a TCP-with-TLS RPC transport class

Use the new TLS handshake API to enable the SunRPC client code
to request a TLS handshake. This implements support for RFC 9289,
only on TCP sockets.

Upper layers such as NFS use RPC-with-TLS to protect in-transit
traffic.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Chuck Lever 2023-06-07 09:59:15 -04:00 committed by Trond Myklebust
parent dea034b963
commit 75eb6af7ac
5 changed files with 418 additions and 0 deletions

View File

@ -200,6 +200,7 @@ enum xprt_transports {
XPRT_TRANSPORT_RDMA = 256,
XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
XPRT_TRANSPORT_LOCAL = 257,
XPRT_TRANSPORT_TCP_TLS = 258,
};
struct rpc_sysfs_xprt;

View File

@ -57,9 +57,11 @@ struct sock_xprt {
struct work_struct error_worker;
struct work_struct recv_worker;
struct mutex recv_mutex;
struct completion handshake_done;
struct sockaddr_storage srcaddr;
unsigned short srcport;
int xprt_err;
struct rpc_clnt *clnt;
/*
* UDP socket buffer size parameters

View File

@ -1525,6 +1525,50 @@ TRACE_EVENT(rpcb_unregister,
)
);
/**
** RPC-over-TLS tracepoints
**/
DECLARE_EVENT_CLASS(rpc_tls_class,
TP_PROTO(
const struct rpc_clnt *clnt,
const struct rpc_xprt *xprt
),
TP_ARGS(clnt, xprt),
TP_STRUCT__entry(
__field(unsigned long, requested_policy)
__field(u32, version)
__string(servername, xprt->servername)
__string(progname, clnt->cl_program->name)
),
TP_fast_assign(
__entry->requested_policy = clnt->cl_xprtsec.policy;
__entry->version = clnt->cl_vers;
__assign_str(servername, xprt->servername);
__assign_str(progname, clnt->cl_program->name)
),
TP_printk("server=%s %sv%u requested_policy=%s",
__get_str(servername), __get_str(progname), __entry->version,
rpc_show_xprtsec_policy(__entry->requested_policy)
)
);
#define DEFINE_RPC_TLS_EVENT(name) \
DEFINE_EVENT(rpc_tls_class, rpc_tls_##name, \
TP_PROTO( \
const struct rpc_clnt *clnt, \
const struct rpc_xprt *xprt \
), \
TP_ARGS(clnt, xprt))
DEFINE_RPC_TLS_EVENT(unavailable);
DEFINE_RPC_TLS_EVENT(not_started);
/* Record an xdr_buf containing a fully-formed RPC message */
DECLARE_EVENT_CLASS(svc_xdr_msg_class,
TP_PROTO(

View File

@ -239,6 +239,7 @@ static ssize_t rpc_sysfs_xprt_dstaddr_store(struct kobject *kobj,
if (!xprt)
return 0;
if (!(xprt->xprt_class->ident == XPRT_TRANSPORT_TCP ||
xprt->xprt_class->ident == XPRT_TRANSPORT_TCP_TLS ||
xprt->xprt_class->ident == XPRT_TRANSPORT_RDMA)) {
xprt_put(xprt);
return -EOPNOTSUPP;

View File

@ -48,6 +48,7 @@
#include <net/udp.h>
#include <net/tcp.h>
#include <net/tls.h>
#include <net/handshake.h>
#include <linux/bvec.h>
#include <linux/highmem.h>
@ -98,6 +99,7 @@ static struct ctl_table_header *sunrpc_table_header;
static struct xprt_class xs_local_transport;
static struct xprt_class xs_udp_transport;
static struct xprt_class xs_tcp_transport;
static struct xprt_class xs_tcp_tls_transport;
static struct xprt_class xs_bc_tcp_transport;
/*
@ -189,6 +191,11 @@ static struct ctl_table xs_tunables_table[] = {
*/
#define XS_IDLE_DISC_TO (5U * 60 * HZ)
/*
* TLS handshake timeout.
*/
#define XS_TLS_HANDSHAKE_TO (10U * HZ)
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
# undef RPC_DEBUG_DATA
# define RPCDBG_FACILITY RPCDBG_TRANS
@ -1243,6 +1250,8 @@ static void xs_reset_transport(struct sock_xprt *transport)
if (atomic_read(&transport->xprt.swapper))
sk_clear_memalloc(sk);
tls_handshake_cancel(sk);
kernel_sock_shutdown(sock, SHUT_RDWR);
mutex_lock(&transport->recv_mutex);
@ -2416,6 +2425,267 @@ static void xs_tcp_setup_socket(struct work_struct *work)
current_restore_flags(pflags, PF_MEMALLOC);
}
/*
* Transfer the connected socket to @upper_transport, then mark that
* xprt CONNECTED.
*/
static int xs_tcp_tls_finish_connecting(struct rpc_xprt *lower_xprt,
struct sock_xprt *upper_transport)
{
struct sock_xprt *lower_transport =
container_of(lower_xprt, struct sock_xprt, xprt);
struct rpc_xprt *upper_xprt = &upper_transport->xprt;
if (!upper_transport->inet) {
struct socket *sock = lower_transport->sock;
struct sock *sk = sock->sk;
/* Avoid temporary address, they are bad for long-lived
* connections such as NFS mounts.
* RFC4941, section 3.6 suggests that:
* Individual applications, which have specific
* knowledge about the normal duration of connections,
* MAY override this as appropriate.
*/
if (xs_addr(upper_xprt)->sa_family == PF_INET6)
ip6_sock_set_addr_preferences(sk, IPV6_PREFER_SRC_PUBLIC);
xs_tcp_set_socket_timeouts(upper_xprt, sock);
tcp_sock_set_nodelay(sk);
lock_sock(sk);
/* @sk is already connected, so it now has the RPC callbacks.
* Reach into @lower_transport to save the original ones.
*/
upper_transport->old_data_ready = lower_transport->old_data_ready;
upper_transport->old_state_change = lower_transport->old_state_change;
upper_transport->old_write_space = lower_transport->old_write_space;
upper_transport->old_error_report = lower_transport->old_error_report;
sk->sk_user_data = upper_xprt;
/* socket options */
sock_reset_flag(sk, SOCK_LINGER);
xprt_clear_connected(upper_xprt);
upper_transport->sock = sock;
upper_transport->inet = sk;
upper_transport->file = lower_transport->file;
release_sock(sk);
/* Reset lower_transport before shutting down its clnt */
mutex_lock(&lower_transport->recv_mutex);
lower_transport->inet = NULL;
lower_transport->sock = NULL;
lower_transport->file = NULL;
xprt_clear_connected(lower_xprt);
xs_sock_reset_connection_flags(lower_xprt);
xs_stream_reset_connect(lower_transport);
mutex_unlock(&lower_transport->recv_mutex);
}
if (!xprt_bound(upper_xprt))
return -ENOTCONN;
xs_set_memalloc(upper_xprt);
if (!xprt_test_and_set_connected(upper_xprt)) {
upper_xprt->connect_cookie++;
clear_bit(XPRT_SOCK_CONNECTING, &upper_transport->sock_state);
xprt_clear_connecting(upper_xprt);
upper_xprt->stat.connect_count++;
upper_xprt->stat.connect_time += (long)jiffies -
upper_xprt->stat.connect_start;
xs_run_error_worker(upper_transport, XPRT_SOCK_WAKE_PENDING);
}
return 0;
}
/**
* xs_tls_handshake_done - TLS handshake completion handler
* @data: address of xprt to wake
* @status: status of handshake
* @peerid: serial number of key containing the remote's identity
*
*/
static void xs_tls_handshake_done(void *data, int status, key_serial_t peerid)
{
struct rpc_xprt *lower_xprt = data;
struct sock_xprt *lower_transport =
container_of(lower_xprt, struct sock_xprt, xprt);
lower_transport->xprt_err = status ? -EACCES : 0;
complete(&lower_transport->handshake_done);
xprt_put(lower_xprt);
}
static int xs_tls_handshake_sync(struct rpc_xprt *lower_xprt, struct xprtsec_parms *xprtsec)
{
struct sock_xprt *lower_transport =
container_of(lower_xprt, struct sock_xprt, xprt);
struct tls_handshake_args args = {
.ta_sock = lower_transport->sock,
.ta_done = xs_tls_handshake_done,
.ta_data = xprt_get(lower_xprt),
.ta_peername = lower_xprt->servername,
};
struct sock *sk = lower_transport->inet;
int rc;
init_completion(&lower_transport->handshake_done);
set_bit(XPRT_SOCK_IGNORE_RECV, &lower_transport->sock_state);
lower_transport->xprt_err = -ETIMEDOUT;
switch (xprtsec->policy) {
case RPC_XPRTSEC_TLS_ANON:
rc = tls_client_hello_anon(&args, GFP_KERNEL);
if (rc)
goto out_put_xprt;
break;
case RPC_XPRTSEC_TLS_X509:
args.ta_my_cert = xprtsec->cert_serial;
args.ta_my_privkey = xprtsec->privkey_serial;
rc = tls_client_hello_x509(&args, GFP_KERNEL);
if (rc)
goto out_put_xprt;
break;
default:
rc = -EACCES;
goto out_put_xprt;
}
rc = wait_for_completion_interruptible_timeout(&lower_transport->handshake_done,
XS_TLS_HANDSHAKE_TO);
if (rc <= 0) {
if (!tls_handshake_cancel(sk)) {
if (rc == 0)
rc = -ETIMEDOUT;
goto out_put_xprt;
}
}
rc = lower_transport->xprt_err;
out:
xs_stream_reset_connect(lower_transport);
clear_bit(XPRT_SOCK_IGNORE_RECV, &lower_transport->sock_state);
return rc;
out_put_xprt:
xprt_put(lower_xprt);
goto out;
}
/**
* xs_tcp_tls_setup_socket - establish a TLS session on a TCP socket
* @work: queued work item
*
* Invoked by a work queue tasklet.
*
* For RPC-with-TLS, there is a two-stage connection process.
*
* The "upper-layer xprt" is visible to the RPC consumer. Once it has
* been marked connected, the consumer knows that a TCP connection and
* a TLS session have been established.
*
* A "lower-layer xprt", created in this function, handles the mechanics
* of connecting the TCP socket, performing the RPC_AUTH_TLS probe, and
* then driving the TLS handshake. Once all that is complete, the upper
* layer xprt is marked connected.
*/
static void xs_tcp_tls_setup_socket(struct work_struct *work)
{
struct sock_xprt *upper_transport =
container_of(work, struct sock_xprt, connect_worker.work);
struct rpc_clnt *upper_clnt = upper_transport->clnt;
struct rpc_xprt *upper_xprt = &upper_transport->xprt;
struct rpc_create_args args = {
.net = upper_xprt->xprt_net,
.protocol = upper_xprt->prot,
.address = (struct sockaddr *)&upper_xprt->addr,
.addrsize = upper_xprt->addrlen,
.timeout = upper_clnt->cl_timeout,
.servername = upper_xprt->servername,
.program = upper_clnt->cl_program,
.prognumber = upper_clnt->cl_prog,
.version = upper_clnt->cl_vers,
.authflavor = RPC_AUTH_TLS,
.cred = upper_clnt->cl_cred,
.xprtsec = {
.policy = RPC_XPRTSEC_NONE,
},
};
unsigned int pflags = current->flags;
struct rpc_clnt *lower_clnt;
struct rpc_xprt *lower_xprt;
int status;
if (atomic_read(&upper_xprt->swapper))
current->flags |= PF_MEMALLOC;
xs_stream_start_connect(upper_transport);
/* This implicitly sends an RPC_AUTH_TLS probe */
lower_clnt = rpc_create(&args);
if (IS_ERR(lower_clnt)) {
trace_rpc_tls_unavailable(upper_clnt, upper_xprt);
clear_bit(XPRT_SOCK_CONNECTING, &upper_transport->sock_state);
xprt_clear_connecting(upper_xprt);
xprt_wake_pending_tasks(upper_xprt, PTR_ERR(lower_clnt));
xs_run_error_worker(upper_transport, XPRT_SOCK_WAKE_PENDING);
goto out_unlock;
}
/* RPC_AUTH_TLS probe was successful. Try a TLS handshake on
* the lower xprt.
*/
rcu_read_lock();
lower_xprt = rcu_dereference(lower_clnt->cl_xprt);
rcu_read_unlock();
status = xs_tls_handshake_sync(lower_xprt, &upper_xprt->xprtsec);
if (status) {
trace_rpc_tls_not_started(upper_clnt, upper_xprt);
goto out_close;
}
status = xs_tcp_tls_finish_connecting(lower_xprt, upper_transport);
if (status)
goto out_close;
trace_rpc_socket_connect(upper_xprt, upper_transport->sock, 0);
if (!xprt_test_and_set_connected(upper_xprt)) {
upper_xprt->connect_cookie++;
clear_bit(XPRT_SOCK_CONNECTING, &upper_transport->sock_state);
xprt_clear_connecting(upper_xprt);
upper_xprt->stat.connect_count++;
upper_xprt->stat.connect_time += (long)jiffies -
upper_xprt->stat.connect_start;
xs_run_error_worker(upper_transport, XPRT_SOCK_WAKE_PENDING);
}
rpc_shutdown_client(lower_clnt);
out_unlock:
current_restore_flags(pflags, PF_MEMALLOC);
upper_transport->clnt = NULL;
xprt_unlock_connect(upper_xprt, upper_transport);
return;
out_close:
rpc_shutdown_client(lower_clnt);
/* xprt_force_disconnect() wakes tasks with a fixed tk_status code.
* Wake them first here to ensure they get our tk_status code.
*/
xprt_wake_pending_tasks(upper_xprt, status);
xs_tcp_force_close(upper_xprt);
xprt_clear_connecting(upper_xprt);
goto out_unlock;
}
/**
* xs_connect - connect a socket to a remote endpoint
* @xprt: pointer to transport structure
@ -2447,6 +2717,7 @@ static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
} else
dprintk("RPC: xs_connect scheduled xprt %p\n", xprt);
transport->clnt = task->tk_client;
queue_delayed_work(xprtiod_workqueue,
&transport->connect_worker,
delay);
@ -3100,6 +3371,94 @@ static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
return ret;
}
/**
* xs_setup_tcp_tls - Set up transport to use a TCP with TLS
* @args: rpc transport creation arguments
*
*/
static struct rpc_xprt *xs_setup_tcp_tls(struct xprt_create *args)
{
struct sockaddr *addr = args->dstaddr;
struct rpc_xprt *xprt;
struct sock_xprt *transport;
struct rpc_xprt *ret;
unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
max_slot_table_size);
if (IS_ERR(xprt))
return xprt;
transport = container_of(xprt, struct sock_xprt, xprt);
xprt->prot = IPPROTO_TCP;
xprt->xprt_class = &xs_tcp_transport;
xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
xprt->bind_timeout = XS_BIND_TO;
xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
xprt->idle_timeout = XS_IDLE_DISC_TO;
xprt->ops = &xs_tcp_ops;
xprt->timeout = &xs_tcp_default_timeout;
xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
xprt->connect_timeout = xprt->timeout->to_initval *
(xprt->timeout->to_retries + 1);
INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
INIT_WORK(&transport->error_worker, xs_error_handle);
switch (args->xprtsec.policy) {
case RPC_XPRTSEC_TLS_ANON:
case RPC_XPRTSEC_TLS_X509:
xprt->xprtsec = args->xprtsec;
INIT_DELAYED_WORK(&transport->connect_worker,
xs_tcp_tls_setup_socket);
break;
default:
ret = ERR_PTR(-EACCES);
goto out_err;
}
switch (addr->sa_family) {
case AF_INET:
if (((struct sockaddr_in *)addr)->sin_port != htons(0))
xprt_set_bound(xprt);
xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
break;
case AF_INET6:
if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
xprt_set_bound(xprt);
xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
break;
default:
ret = ERR_PTR(-EAFNOSUPPORT);
goto out_err;
}
if (xprt_bound(xprt))
dprintk("RPC: set up xprt to %s (port %s) via %s\n",
xprt->address_strings[RPC_DISPLAY_ADDR],
xprt->address_strings[RPC_DISPLAY_PORT],
xprt->address_strings[RPC_DISPLAY_PROTO]);
else
dprintk("RPC: set up xprt to %s (autobind) via %s\n",
xprt->address_strings[RPC_DISPLAY_ADDR],
xprt->address_strings[RPC_DISPLAY_PROTO]);
if (try_module_get(THIS_MODULE))
return xprt;
ret = ERR_PTR(-EINVAL);
out_err:
xs_xprt_free(xprt);
return ret;
}
/**
* xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
* @args: rpc transport creation arguments
@ -3209,6 +3568,15 @@ static struct xprt_class xs_tcp_transport = {
.netid = { "tcp", "tcp6", "" },
};
static struct xprt_class xs_tcp_tls_transport = {
.list = LIST_HEAD_INIT(xs_tcp_tls_transport.list),
.name = "tcp-with-tls",
.owner = THIS_MODULE,
.ident = XPRT_TRANSPORT_TCP_TLS,
.setup = xs_setup_tcp_tls,
.netid = { "tcp", "tcp6", "" },
};
static struct xprt_class xs_bc_tcp_transport = {
.list = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
.name = "tcp NFSv4.1 backchannel",
@ -3230,6 +3598,7 @@ int init_socket_xprt(void)
xprt_register_transport(&xs_local_transport);
xprt_register_transport(&xs_udp_transport);
xprt_register_transport(&xs_tcp_transport);
xprt_register_transport(&xs_tcp_tls_transport);
xprt_register_transport(&xs_bc_tcp_transport);
return 0;
@ -3249,6 +3618,7 @@ void cleanup_socket_xprt(void)
xprt_unregister_transport(&xs_local_transport);
xprt_unregister_transport(&xs_udp_transport);
xprt_unregister_transport(&xs_tcp_transport);
xprt_unregister_transport(&xs_tcp_tls_transport);
xprt_unregister_transport(&xs_bc_tcp_transport);
}