On Fri, May 19, 2023 at 2:33 PM Chuck Lever III <chuck.lever@xxxxxxxxxx> wrote:
>
>
>
> > On May 19, 2023, at 2:19 PM, Anna Schumaker <schumaker.anna@xxxxxxxxx> wrote:
> >
> > Hi Chuck,
> >
> > On Tue, May 16, 2023 at 3:52 PM Chuck Lever <cel@xxxxxxxxxx> wrote:
> >>
> >> From: Chuck Lever <chuck.lever@xxxxxxxxxx>
> >>
> >> Use the new TLS handshake API to enable the SunRPC client code
> >> to request a TLS handshake. This implements support for RFC 9289.
> >>
> >> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> >> ---
> >> include/linux/sunrpc/xprtsock.h | 1
> >> net/sunrpc/xprtsock.c | 289 ++++++++++++++++++++++++++++++++++-----
> >> 2 files changed, 253 insertions(+), 37 deletions(-)
> >>
> >> diff --git a/include/linux/sunrpc/xprtsock.h b/include/linux/sunrpc/xprtsock.h
> >> index 574a6a5391ba..700a1e6c047c 100644
> >> --- a/include/linux/sunrpc/xprtsock.h
> >> +++ b/include/linux/sunrpc/xprtsock.h
> >> @@ -57,6 +57,7 @@ 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;
> >> diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
> >> index 7ea5984a52a3..686dd313f89f 100644
> >> --- a/net/sunrpc/xprtsock.c
> >> +++ b/net/sunrpc/xprtsock.c
> >> @@ -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>
> >> @@ -189,6 +190,11 @@ 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
> >> @@ -1238,6 +1244,10 @@ static void xs_reset_transport(struct sock_xprt *transport)
> >> if (atomic_read(&transport->xprt.swapper))
> >> sk_clear_memalloc(sk);
> >>
> >> + /* XXX: Maybe also send a TLS Closure alert? */
> >> +
> >> + tls_handshake_cancel(sk);
> >> +
> >> kernel_sock_shutdown(sock, SHUT_RDWR);
> >>
> >> mutex_lock(&transport->recv_mutex);
> >> @@ -2411,60 +2421,266 @@ 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_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_connect - establish a TLS session on a socket
> >> - * @work: queued work item
> >> + * 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_connect(struct work_struct *work)
> >> +static void xs_tls_handshake_done(void *data, int status, key_serial_t peerid)
> >> {
> >> - struct sock_xprt *transport =
> >> - container_of(work, struct sock_xprt, connect_worker.work);
> >> - struct rpc_clnt *clnt;
> >> + struct rpc_xprt *lower_xprt = data;
> >> + struct sock_xprt *lower_transport =
> >> + container_of(lower_xprt, struct sock_xprt, xprt);
> >>
> >> - clnt = transport->clnt;
> >> - transport->clnt = NULL;
> >> - if (IS_ERR(clnt))
> >> - goto out_unlock;
> >> + lower_transport->xprt_err = status ? -EACCES : 0;
> >> + complete(&lower_transport->handshake_done);
> >> + xprt_put(lower_xprt);
> >> +}
> >>
> >> - xs_tcp_setup_socket(work);
> >> +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,
> >
> > This part isn't compiling for me on v6.4-rc2:
> >
> > net/sunrpc/xprtsock.c:2538:4: error: field designator 'ta_peername'
> > does not refer to any field in type 'struct tls_handshake_args'
> > .ta_peername = lower_xprt->servername,
> > ^
> > 1 error generated.
> >
> > Am I missing a patch, or did this struct get changed somewhere along the line?
>
> The patch series is based on net-next, which includes a patch
> that changes this code.
>
> I had expected those patches to have been merged, but they are
> still pending.
Makes sense! I wonder what the hold up is. Oh well, I'll rebase on top
of that and try again :)
Anna
>
>
> > Anna
> >
> >> + };
> >> + struct sock *sk = lower_transport->inet;
> >> + int rc;
> >>
> >> - rpc_shutdown_client(clnt);
> >> + init_completion(&lower_transport->handshake_done);
> >> + set_bit(XPRT_SOCK_IGNORE_RECV, &lower_transport->sock_state);
> >>
> >> -out_unlock:
> >> - return;
> >> + 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;
> >> }
> >>
> >> -static void xs_set_transport_clnt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
> >> +/**
> >> + * xs_tls_connect - establish a TLS session on a socket
> >> + * @work: queued work item
> >> + *
> >> + * 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_tls_connect(struct work_struct *work)
> >> {
> >> - struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
> >> + 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 = xprt->xprt_net,
> >> - .protocol = xprt->prot,
> >> - .address = (struct sockaddr *)&xprt->addr,
> >> - .addrsize = xprt->addrlen,
> >> - .timeout = clnt->cl_timeout,
> >> - .servername = xprt->servername,
> >> - .nodename = clnt->cl_nodename,
> >> - .program = clnt->cl_program,
> >> - .prognumber = clnt->cl_prog,
> >> - .version = clnt->cl_vers,
> >> + .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,
> >> + .nodename = upper_clnt->cl_nodename,
> >> + .program = upper_clnt->cl_program,
> >> + .prognumber = upper_clnt->cl_prog,
> >> + .version = upper_clnt->cl_vers,
> >> .authflavor = RPC_AUTH_TLS,
> >> - .cred = clnt->cl_cred,
> >> + .cred = upper_clnt->cl_cred,
> >> .xprtsec = {
> >> .policy = RPC_XPRTSEC_NONE,
> >> },
> >> - .flags = RPC_CLNT_CREATE_NOPING,
> >> };
> >> + unsigned int pflags = current->flags;
> >> + struct rpc_clnt *lower_clnt;
> >> + struct rpc_xprt *lower_xprt;
> >> + int status;
> >>
> >> - switch (xprt->xprtsec.policy) {
> >> - case RPC_XPRTSEC_TLS_ANON:
> >> - case RPC_XPRTSEC_TLS_X509:
> >> - transport->clnt = rpc_create(&args);
> >> - break;
> >> - default:
> >> - transport->clnt = ERR_PTR(-ENOTCONN);
> >> + 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)) {
> >> + clear_bit(XPRT_SOCK_CONNECTING, &upper_transport->sock_state);
> >> + xprt_clear_connecting(upper_xprt);
> >> + xprt_wake_pending_tasks(upper_xprt, PTR_ERR(lower_clnt));
> >> + smp_mb__before_atomic();
> >> + 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)
> >> + goto out_close;
> >> +
> >> + status = xs_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;
> >> }
> >>
> >> /**
> >> @@ -2498,8 +2714,7 @@ static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
> >> } else
> >> dprintk("RPC: xs_connect scheduled xprt %p\n", xprt);
> >>
> >> - xs_set_transport_clnt(task->tk_client, xprt);
> >> -
> >> + transport->clnt = task->tk_client;
> >> queue_delayed_work(xprtiod_workqueue,
> >> &transport->connect_worker,
> >> delay);
>
>
> --
> Chuck Lever
>
>
