Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 479 insertions, 0 deletions

diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
new file mode 100644
index 0000000000..0f5a1d77b8
--- /dev/null
+++ b/net/rxrpc/call_accept.c
@@ -0,0 +1,479 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* incoming call handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/errqueue.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/icmp.h>
+#include <linux/gfp.h>
+#include <linux/circ_buf.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include "ar-internal.h"
+
+static void rxrpc_dummy_notify(struct sock *sk, struct rxrpc_call *call,
+			       unsigned long user_call_ID)
+{
+}
+
+/*
+ * Preallocate a single service call, connection and peer and, if possible,
+ * give them a user ID and attach the user's side of the ID to them.
+ */
+static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx,
+				      struct rxrpc_backlog *b,
+				      rxrpc_notify_rx_t notify_rx,
+				      rxrpc_user_attach_call_t user_attach_call,
+				      unsigned long user_call_ID, gfp_t gfp,
+				      unsigned int debug_id)
+{
+	struct rxrpc_call *call, *xcall;
+	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
+	struct rb_node *parent, **pp;
+	int max, tmp;
+	unsigned int size = RXRPC_BACKLOG_MAX;
+	unsigned int head, tail, call_head, call_tail;
+
+	max = rx->sk.sk_max_ack_backlog;
+	tmp = rx->sk.sk_ack_backlog;
+	if (tmp >= max) {
+		_leave(" = -ENOBUFS [full %u]", max);
+		return -ENOBUFS;
+	}
+	max -= tmp;
+
+	/* We don't need more conns and peers than we have calls, but on the
+	 * other hand, we shouldn't ever use more peers than conns or conns
+	 * than calls.
+	 */
+	call_head = b->call_backlog_head;
+	call_tail = READ_ONCE(b->call_backlog_tail);
+	tmp = CIRC_CNT(call_head, call_tail, size);
+	if (tmp >= max) {
+		_leave(" = -ENOBUFS [enough %u]", tmp);
+		return -ENOBUFS;
+	}
+	max = tmp + 1;
+
+	head = b->peer_backlog_head;
+	tail = READ_ONCE(b->peer_backlog_tail);
+	if (CIRC_CNT(head, tail, size) < max) {
+		struct rxrpc_peer *peer;
+
+		peer = rxrpc_alloc_peer(rx->local, gfp, rxrpc_peer_new_prealloc);
+		if (!peer)
+			return -ENOMEM;
+		b->peer_backlog[head] = peer;
+		smp_store_release(&b->peer_backlog_head,
+				  (head + 1) & (size - 1));
+	}
+
+	head = b->conn_backlog_head;
+	tail = READ_ONCE(b->conn_backlog_tail);
+	if (CIRC_CNT(head, tail, size) < max) {
+		struct rxrpc_connection *conn;
+
+		conn = rxrpc_prealloc_service_connection(rxnet, gfp);
+		if (!conn)
+			return -ENOMEM;
+		b->conn_backlog[head] = conn;
+		smp_store_release(&b->conn_backlog_head,
+				  (head + 1) & (size - 1));
+	}
+
+	/* Now it gets complicated, because calls get registered with the
+	 * socket here, with a user ID preassigned by the user.
+	 */
+	call = rxrpc_alloc_call(rx, gfp, debug_id);
+	if (!call)
+		return -ENOMEM;
+	call->flags |= (1 << RXRPC_CALL_IS_SERVICE);
+	rxrpc_set_call_state(call, RXRPC_CALL_SERVER_PREALLOC);
+	__set_bit(RXRPC_CALL_EV_INITIAL_PING, &call->events);
+
+	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
+			 user_call_ID, rxrpc_call_new_prealloc_service);
+
+	write_lock(&rx->call_lock);
+
+	/* Check the user ID isn't already in use */
+	pp = &rx->calls.rb_node;
+	parent = NULL;
+	while (*pp) {
+		parent = *pp;
+		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
+		if (user_call_ID < xcall->user_call_ID)
+			pp = &(*pp)->rb_left;
+		else if (user_call_ID > xcall->user_call_ID)
+			pp = &(*pp)->rb_right;
+		else
+			goto id_in_use;
+	}
+
+	call->user_call_ID = user_call_ID;
+	call->notify_rx = notify_rx;
+	if (user_attach_call) {
+		rxrpc_get_call(call, rxrpc_call_get_kernel_service);
+		user_attach_call(call, user_call_ID);
+	}
+
+	rxrpc_get_call(call, rxrpc_call_get_userid);
+	rb_link_node(&call->sock_node, parent, pp);
+	rb_insert_color(&call->sock_node, &rx->calls);
+	set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
+
+	list_add(&call->sock_link, &rx->sock_calls);
+
+	write_unlock(&rx->call_lock);
+
+	rxnet = call->rxnet;
+	spin_lock(&rxnet->call_lock);
+	list_add_tail_rcu(&call->link, &rxnet->calls);
+	spin_unlock(&rxnet->call_lock);
+
+	b->call_backlog[call_head] = call;
+	smp_store_release(&b->call_backlog_head, (call_head + 1) & (size - 1));
+	_leave(" = 0 [%d -> %lx]", call->debug_id, user_call_ID);
+	return 0;
+
+id_in_use:
+	write_unlock(&rx->call_lock);
+	rxrpc_cleanup_call(call);
+	_leave(" = -EBADSLT");
+	return -EBADSLT;
+}
+
+/*
+ * Allocate the preallocation buffers for incoming service calls.  These must
+ * be charged manually.
+ */
+int rxrpc_service_prealloc(struct rxrpc_sock *rx, gfp_t gfp)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+
+	if (!b) {
+		b = kzalloc(sizeof(struct rxrpc_backlog), gfp);
+		if (!b)
+			return -ENOMEM;
+		rx->backlog = b;
+	}
+
+	return 0;
+}
+
+/*
+ * Discard the preallocation on a service.
+ */
+void rxrpc_discard_prealloc(struct rxrpc_sock *rx)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
+	unsigned int size = RXRPC_BACKLOG_MAX, head, tail;
+
+	if (!b)
+		return;
+	rx->backlog = NULL;
+
+	/* Make sure that there aren't any incoming calls in progress before we
+	 * clear the preallocation buffers.
+	 */
+	spin_lock(&rx->incoming_lock);
+	spin_unlock(&rx->incoming_lock);
+
+	head = b->peer_backlog_head;
+	tail = b->peer_backlog_tail;
+	while (CIRC_CNT(head, tail, size) > 0) {
+		struct rxrpc_peer *peer = b->peer_backlog[tail];
+		rxrpc_put_local(peer->local, rxrpc_local_put_prealloc_peer);
+		kfree(peer);
+		tail = (tail + 1) & (size - 1);
+	}
+
+	head = b->conn_backlog_head;
+	tail = b->conn_backlog_tail;
+	while (CIRC_CNT(head, tail, size) > 0) {
+		struct rxrpc_connection *conn = b->conn_backlog[tail];
+		write_lock(&rxnet->conn_lock);
+		list_del(&conn->link);
+		list_del(&conn->proc_link);
+		write_unlock(&rxnet->conn_lock);
+		kfree(conn);
+		if (atomic_dec_and_test(&rxnet->nr_conns))
+			wake_up_var(&rxnet->nr_conns);
+		tail = (tail + 1) & (size - 1);
+	}
+
+	head = b->call_backlog_head;
+	tail = b->call_backlog_tail;
+	while (CIRC_CNT(head, tail, size) > 0) {
+		struct rxrpc_call *call = b->call_backlog[tail];
+		rcu_assign_pointer(call->socket, rx);
+		if (rx->discard_new_call) {
+			_debug("discard %lx", call->user_call_ID);
+			rx->discard_new_call(call, call->user_call_ID);
+			if (call->notify_rx)
+				call->notify_rx = rxrpc_dummy_notify;
+			rxrpc_put_call(call, rxrpc_call_put_kernel);
+		}
+		rxrpc_call_completed(call);
+		rxrpc_release_call(rx, call);
+		rxrpc_put_call(call, rxrpc_call_put_discard_prealloc);
+		tail = (tail + 1) & (size - 1);
+	}
+
+	kfree(b);
+}
+
+/*
+ * Allocate a new incoming call from the prealloc pool, along with a connection
+ * and a peer as necessary.
+ */
+static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
+						    struct rxrpc_local *local,
+						    struct rxrpc_peer *peer,
+						    struct rxrpc_connection *conn,
+						    const struct rxrpc_security *sec,
+						    struct sockaddr_rxrpc *peer_srx,
+						    struct sk_buff *skb)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+	struct rxrpc_call *call;
+	unsigned short call_head, conn_head, peer_head;
+	unsigned short call_tail, conn_tail, peer_tail;
+	unsigned short call_count, conn_count;
+
+	/* #calls >= #conns >= #peers must hold true. */
+	call_head = smp_load_acquire(&b->call_backlog_head);
+	call_tail = b->call_backlog_tail;
+	call_count = CIRC_CNT(call_head, call_tail, RXRPC_BACKLOG_MAX);
+	conn_head = smp_load_acquire(&b->conn_backlog_head);
+	conn_tail = b->conn_backlog_tail;
+	conn_count = CIRC_CNT(conn_head, conn_tail, RXRPC_BACKLOG_MAX);
+	ASSERTCMP(conn_count, >=, call_count);
+	peer_head = smp_load_acquire(&b->peer_backlog_head);
+	peer_tail = b->peer_backlog_tail;
+	ASSERTCMP(CIRC_CNT(peer_head, peer_tail, RXRPC_BACKLOG_MAX), >=,
+		  conn_count);
+
+	if (call_count == 0)
+		return NULL;
+
+	if (!conn) {
+		if (peer && !rxrpc_get_peer_maybe(peer, rxrpc_peer_get_service_conn))
+			peer = NULL;
+		if (!peer) {
+			peer = b->peer_backlog[peer_tail];
+			peer->srx = *peer_srx;
+			b->peer_backlog[peer_tail] = NULL;
+			smp_store_release(&b->peer_backlog_tail,
+					  (peer_tail + 1) &
+					  (RXRPC_BACKLOG_MAX - 1));
+
+			rxrpc_new_incoming_peer(local, peer);
+		}
+
+		/* Now allocate and set up the connection */
+		conn = b->conn_backlog[conn_tail];
+		b->conn_backlog[conn_tail] = NULL;
+		smp_store_release(&b->conn_backlog_tail,
+				  (conn_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
+		conn->local = rxrpc_get_local(local, rxrpc_local_get_prealloc_conn);
+		conn->peer = peer;
+		rxrpc_see_connection(conn, rxrpc_conn_see_new_service_conn);
+		rxrpc_new_incoming_connection(rx, conn, sec, skb);
+	} else {
+		rxrpc_get_connection(conn, rxrpc_conn_get_service_conn);
+		atomic_inc(&conn->active);
+	}
+
+	/* And now we can allocate and set up a new call */
+	call = b->call_backlog[call_tail];
+	b->call_backlog[call_tail] = NULL;
+	smp_store_release(&b->call_backlog_tail,
+			  (call_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
+
+	rxrpc_see_call(call, rxrpc_call_see_accept);
+	call->local = rxrpc_get_local(conn->local, rxrpc_local_get_call);
+	call->conn = conn;
+	call->security = conn->security;
+	call->security_ix = conn->security_ix;
+	call->peer = rxrpc_get_peer(conn->peer, rxrpc_peer_get_accept);
+	call->dest_srx = peer->srx;
+	call->cong_ssthresh = call->peer->cong_ssthresh;
+	call->tx_last_sent = ktime_get_real();
+	return call;
+}
+
+/*
+ * Set up a new incoming call.  Called from the I/O thread.
+ *
+ * If this is for a kernel service, when we allocate the call, it will have
+ * three refs on it: (1) the kernel service, (2) the user_call_ID tree, (3) the
+ * retainer ref obtained from the backlog buffer.  Prealloc calls for userspace
+ * services only have the ref from the backlog buffer.
+ *
+ * If we want to report an error, we mark the skb with the packet type and
+ * abort code and return false.
+ */
+bool rxrpc_new_incoming_call(struct rxrpc_local *local,
+			     struct rxrpc_peer *peer,
+			     struct rxrpc_connection *conn,
+			     struct sockaddr_rxrpc *peer_srx,
+			     struct sk_buff *skb)
+{
+	const struct rxrpc_security *sec = NULL;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_call *call = NULL;
+	struct rxrpc_sock *rx;
+
+	_enter("");
+
+	/* Don't set up a call for anything other than a DATA packet. */
+	if (sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
+		return rxrpc_protocol_error(skb, rxrpc_eproto_no_service_call);
+
+	read_lock(&local->services_lock);
+
+	/* Weed out packets to services we're not offering.  Packets that would
+	 * begin a call are explicitly rejected and the rest are just
+	 * discarded.
+	 */
+	rx = local->service;
+	if (!rx || (sp->hdr.serviceId != rx->srx.srx_service &&
+		    sp->hdr.serviceId != rx->second_service)
+	    ) {
+		if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
+		    sp->hdr.seq == 1)
+			goto unsupported_service;
+		goto discard;
+	}
+
+	if (!conn) {
+		sec = rxrpc_get_incoming_security(rx, skb);
+		if (!sec)
+			goto unsupported_security;
+	}
+
+	spin_lock(&rx->incoming_lock);
+	if (rx->sk.sk_state == RXRPC_SERVER_LISTEN_DISABLED ||
+	    rx->sk.sk_state == RXRPC_CLOSE) {
+		rxrpc_direct_abort(skb, rxrpc_abort_shut_down,
+				   RX_INVALID_OPERATION, -ESHUTDOWN);
+		goto no_call;
+	}
+
+	call = rxrpc_alloc_incoming_call(rx, local, peer, conn, sec, peer_srx,
+					 skb);
+	if (!call) {
+		skb->mark = RXRPC_SKB_MARK_REJECT_BUSY;
+		goto no_call;
+	}
+
+	trace_rxrpc_receive(call, rxrpc_receive_incoming,
+			    sp->hdr.serial, sp->hdr.seq);
+
+	/* Make the call live. */
+	rxrpc_incoming_call(rx, call, skb);
+	conn = call->conn;
+
+	if (rx->notify_new_call)
+		rx->notify_new_call(&rx->sk, call, call->user_call_ID);
+
+	spin_lock(&conn->state_lock);
+	if (conn->state == RXRPC_CONN_SERVICE_UNSECURED) {
+		conn->state = RXRPC_CONN_SERVICE_CHALLENGING;
+		set_bit(RXRPC_CONN_EV_CHALLENGE, &call->conn->events);
+		rxrpc_queue_conn(call->conn, rxrpc_conn_queue_challenge);
+	}
+	spin_unlock(&conn->state_lock);
+
+	spin_unlock(&rx->incoming_lock);
+	read_unlock(&local->services_lock);
+
+	if (hlist_unhashed(&call->error_link)) {
+		spin_lock(&call->peer->lock);
+		hlist_add_head(&call->error_link, &call->peer->error_targets);
+		spin_unlock(&call->peer->lock);
+	}
+
+	_leave(" = %p{%d}", call, call->debug_id);
+	rxrpc_input_call_event(call, skb);
+	rxrpc_put_call(call, rxrpc_call_put_input);
+	return true;
+
+unsupported_service:
+	read_unlock(&local->services_lock);
+	return rxrpc_direct_abort(skb, rxrpc_abort_service_not_offered,
+				  RX_INVALID_OPERATION, -EOPNOTSUPP);
+unsupported_security:
+	read_unlock(&local->services_lock);
+	return rxrpc_direct_abort(skb, rxrpc_abort_service_not_offered,
+				  RX_INVALID_OPERATION, -EKEYREJECTED);
+no_call:
+	spin_unlock(&rx->incoming_lock);
+	read_unlock(&local->services_lock);
+	_leave(" = f [%u]", skb->mark);
+	return false;
+discard:
+	read_unlock(&local->services_lock);
+	return true;
+}
+
+/*
+ * Charge up socket with preallocated calls, attaching user call IDs.
+ */
+int rxrpc_user_charge_accept(struct rxrpc_sock *rx, unsigned long user_call_ID)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+
+	if (rx->sk.sk_state == RXRPC_CLOSE)
+		return -ESHUTDOWN;
+
+	return rxrpc_service_prealloc_one(rx, b, NULL, NULL, user_call_ID,
+					  GFP_KERNEL,
+					  atomic_inc_return(&rxrpc_debug_id));
+}
+
+/*
+ * rxrpc_kernel_charge_accept - Charge up socket with preallocated calls
+ * @sock: The socket on which to preallocate
+ * @notify_rx: Event notification function for the call
+ * @user_attach_call: Func to attach call to user_call_ID
+ * @user_call_ID: The tag to attach to the preallocated call
+ * @gfp: The allocation conditions.
+ * @debug_id: The tracing debug ID.
+ *
+ * Charge up the socket with preallocated calls, each with a user ID.  A
+ * function should be provided to effect the attachment from the user's side.
+ * The user is given a ref to hold on the call.
+ *
+ * Note that the call may be come connected before this function returns.
+ */
+int rxrpc_kernel_charge_accept(struct socket *sock,
+			       rxrpc_notify_rx_t notify_rx,
+			       rxrpc_user_attach_call_t user_attach_call,
+			       unsigned long user_call_ID, gfp_t gfp,
+			       unsigned int debug_id)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	struct rxrpc_backlog *b = rx->backlog;
+
+	if (sock->sk->sk_state == RXRPC_CLOSE)
+		return -ESHUTDOWN;
+
+	return rxrpc_service_prealloc_one(rx, b, notify_rx,
+					  user_attach_call, user_call_ID,
+					  gfp, debug_id);
+}
+EXPORT_SYMBOL(rxrpc_kernel_charge_accept);