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