blob: 3f9476508204aa3f1e3bcb037934f2183730afc2 [file] [log] [blame]
/* RxRPC individual remote procedure call handling
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/circ_buf.h>
#include <linux/spinlock_types.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
/*
* Maximum lifetime of a call (in jiffies).
*/
unsigned int rxrpc_max_call_lifetime = 60 * HZ;
const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
[RXRPC_CALL_UNINITIALISED] = "Uninit ",
[RXRPC_CALL_CLIENT_AWAIT_CONN] = "ClWtConn",
[RXRPC_CALL_CLIENT_SEND_REQUEST] = "ClSndReq",
[RXRPC_CALL_CLIENT_AWAIT_REPLY] = "ClAwtRpl",
[RXRPC_CALL_CLIENT_RECV_REPLY] = "ClRcvRpl",
[RXRPC_CALL_SERVER_PREALLOC] = "SvPrealc",
[RXRPC_CALL_SERVER_SECURING] = "SvSecure",
[RXRPC_CALL_SERVER_ACCEPTING] = "SvAccept",
[RXRPC_CALL_SERVER_RECV_REQUEST] = "SvRcvReq",
[RXRPC_CALL_SERVER_ACK_REQUEST] = "SvAckReq",
[RXRPC_CALL_SERVER_SEND_REPLY] = "SvSndRpl",
[RXRPC_CALL_SERVER_AWAIT_ACK] = "SvAwtACK",
[RXRPC_CALL_COMPLETE] = "Complete",
};
const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
[RXRPC_CALL_SUCCEEDED] = "Complete",
[RXRPC_CALL_REMOTELY_ABORTED] = "RmtAbort",
[RXRPC_CALL_LOCALLY_ABORTED] = "LocAbort",
[RXRPC_CALL_LOCAL_ERROR] = "LocError",
[RXRPC_CALL_NETWORK_ERROR] = "NetError",
};
const char rxrpc_call_traces[rxrpc_call__nr_trace][4] = {
[rxrpc_call_new_client] = "NWc",
[rxrpc_call_new_service] = "NWs",
[rxrpc_call_queued] = "QUE",
[rxrpc_call_queued_ref] = "QUR",
[rxrpc_call_seen] = "SEE",
[rxrpc_call_got] = "GOT",
[rxrpc_call_got_userid] = "Gus",
[rxrpc_call_got_kernel] = "Gke",
[rxrpc_call_put] = "PUT",
[rxrpc_call_put_userid] = "Pus",
[rxrpc_call_put_kernel] = "Pke",
[rxrpc_call_put_noqueue] = "PNQ",
};
struct kmem_cache *rxrpc_call_jar;
LIST_HEAD(rxrpc_calls);
DEFINE_RWLOCK(rxrpc_call_lock);
static void rxrpc_call_timer_expired(unsigned long _call)
{
struct rxrpc_call *call = (struct rxrpc_call *)_call;
_enter("%d", call->debug_id);
if (call->state < RXRPC_CALL_COMPLETE)
rxrpc_queue_call(call);
}
/*
* find an extant server call
* - called in process context with IRQs enabled
*/
struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
unsigned long user_call_ID)
{
struct rxrpc_call *call;
struct rb_node *p;
_enter("%p,%lx", rx, user_call_ID);
read_lock(&rx->call_lock);
p = rx->calls.rb_node;
while (p) {
call = rb_entry(p, struct rxrpc_call, sock_node);
if (user_call_ID < call->user_call_ID)
p = p->rb_left;
else if (user_call_ID > call->user_call_ID)
p = p->rb_right;
else
goto found_extant_call;
}
read_unlock(&rx->call_lock);
_leave(" = NULL");
return NULL;
found_extant_call:
rxrpc_get_call(call, rxrpc_call_got);
read_unlock(&rx->call_lock);
_leave(" = %p [%d]", call, atomic_read(&call->usage));
return call;
}
/*
* allocate a new call
*/
struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
{
struct rxrpc_call *call;
call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
if (!call)
return NULL;
call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE,
sizeof(struct sk_buff *),
gfp);
if (!call->rxtx_buffer)
goto nomem;
call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp);
if (!call->rxtx_annotations)
goto nomem_2;
setup_timer(&call->timer, rxrpc_call_timer_expired,
(unsigned long)call);
INIT_WORK(&call->processor, &rxrpc_process_call);
INIT_LIST_HEAD(&call->link);
INIT_LIST_HEAD(&call->chan_wait_link);
INIT_LIST_HEAD(&call->accept_link);
INIT_LIST_HEAD(&call->recvmsg_link);
INIT_LIST_HEAD(&call->sock_link);
init_waitqueue_head(&call->waitq);
spin_lock_init(&call->lock);
rwlock_init(&call->state_lock);
atomic_set(&call->usage, 1);
call->debug_id = atomic_inc_return(&rxrpc_debug_id);
memset(&call->sock_node, 0xed, sizeof(call->sock_node));
/* Leave space in the ring to handle a maxed-out jumbo packet */
call->rx_winsize = RXRPC_RXTX_BUFF_SIZE - 1 - 46;
call->tx_winsize = 16;
call->rx_expect_next = 1;
return call;
nomem_2:
kfree(call->rxtx_buffer);
nomem:
kmem_cache_free(rxrpc_call_jar, call);
return NULL;
}
/*
* Allocate a new client call.
*/
static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx,
gfp_t gfp)
{
struct rxrpc_call *call;
_enter("");
call = rxrpc_alloc_call(gfp);
if (!call)
return ERR_PTR(-ENOMEM);
call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
call->service_id = srx->srx_service;
_leave(" = %p", call);
return call;
}
/*
* Initiate the call ack/resend/expiry timer.
*/
static void rxrpc_start_call_timer(struct rxrpc_call *call)
{
unsigned long expire_at;
expire_at = jiffies + rxrpc_max_call_lifetime;
call->expire_at = expire_at;
call->ack_at = expire_at;
call->resend_at = expire_at;
call->timer.expires = expire_at;
add_timer(&call->timer);
}
/*
* set up a call for the given data
* - called in process context with IRQs enabled
*/
struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
struct rxrpc_conn_parameters *cp,
struct sockaddr_rxrpc *srx,
unsigned long user_call_ID,
gfp_t gfp)
{
struct rxrpc_call *call, *xcall;
struct rb_node *parent, **pp;
const void *here = __builtin_return_address(0);
int ret;
_enter("%p,%lx", rx, user_call_ID);
call = rxrpc_alloc_client_call(srx, gfp);
if (IS_ERR(call)) {
_leave(" = %ld", PTR_ERR(call));
return call;
}
trace_rxrpc_call(call, 0, atomic_read(&call->usage), here,
(const void *)user_call_ID);
/* Publish the call, even though it is incompletely set up as yet */
call->user_call_ID = user_call_ID;
__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
write_lock(&rx->call_lock);
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 found_user_ID_now_present;
}
rcu_assign_pointer(call->socket, rx);
rxrpc_get_call(call, rxrpc_call_got_userid);
rb_link_node(&call->sock_node, parent, pp);
rb_insert_color(&call->sock_node, &rx->calls);
list_add(&call->sock_link, &rx->sock_calls);
write_unlock(&rx->call_lock);
write_lock(&rxrpc_call_lock);
list_add_tail(&call->link, &rxrpc_calls);
write_unlock(&rxrpc_call_lock);
/* Set up or get a connection record and set the protocol parameters,
* including channel number and call ID.
*/
ret = rxrpc_connect_call(call, cp, srx, gfp);
if (ret < 0)
goto error;
spin_lock_bh(&call->conn->params.peer->lock);
hlist_add_head(&call->error_link,
&call->conn->params.peer->error_targets);
spin_unlock_bh(&call->conn->params.peer->lock);
rxrpc_start_call_timer(call);
_net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
_leave(" = %p [new]", call);
return call;
error:
write_lock(&rx->call_lock);
rb_erase(&call->sock_node, &rx->calls);
write_unlock(&rx->call_lock);
rxrpc_put_call(call, rxrpc_call_put_userid);
write_lock(&rxrpc_call_lock);
list_del_init(&call->link);
write_unlock(&rxrpc_call_lock);
error_out:
__rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
RX_CALL_DEAD, ret);
set_bit(RXRPC_CALL_RELEASED, &call->flags);
rxrpc_put_call(call, rxrpc_call_put);
_leave(" = %d", ret);
return ERR_PTR(ret);
/* We unexpectedly found the user ID in the list after taking
* the call_lock. This shouldn't happen unless the user races
* with itself and tries to add the same user ID twice at the
* same time in different threads.
*/
found_user_ID_now_present:
write_unlock(&rx->call_lock);
ret = -EEXIST;
goto error_out;
}
/*
* Set up an incoming call. call->conn points to the connection.
* This is called in BH context and isn't allowed to fail.
*/
void rxrpc_incoming_call(struct rxrpc_sock *rx,
struct rxrpc_call *call,
struct sk_buff *skb)
{
struct rxrpc_connection *conn = call->conn;
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
u32 chan;
_enter(",%d", call->conn->debug_id);
rcu_assign_pointer(call->socket, rx);
call->call_id = sp->hdr.callNumber;
call->service_id = sp->hdr.serviceId;
call->cid = sp->hdr.cid;
call->state = RXRPC_CALL_SERVER_ACCEPTING;
if (sp->hdr.securityIndex > 0)
call->state = RXRPC_CALL_SERVER_SECURING;
/* Set the channel for this call. We don't get channel_lock as we're
* only defending against the data_ready handler (which we're called
* from) and the RESPONSE packet parser (which is only really
* interested in call_counter and can cope with a disagreement with the
* call pointer).
*/
chan = sp->hdr.cid & RXRPC_CHANNELMASK;
conn->channels[chan].call_counter = call->call_id;
conn->channels[chan].call_id = call->call_id;
rcu_assign_pointer(conn->channels[chan].call, call);
spin_lock(&conn->params.peer->lock);
hlist_add_head(&call->error_link, &conn->params.peer->error_targets);
spin_unlock(&conn->params.peer->lock);
_net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
rxrpc_start_call_timer(call);
_leave("");
}
/*
* Queue a call's work processor, getting a ref to pass to the work queue.
*/
bool rxrpc_queue_call(struct rxrpc_call *call)
{
const void *here = __builtin_return_address(0);
int n = __atomic_add_unless(&call->usage, 1, 0);
if (n == 0)
return false;
if (rxrpc_queue_work(&call->processor))
trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL);
else
rxrpc_put_call(call, rxrpc_call_put_noqueue);
return true;
}
/*
* Queue a call's work processor, passing the callers ref to the work queue.
*/
bool __rxrpc_queue_call(struct rxrpc_call *call)
{
const void *here = __builtin_return_address(0);
int n = atomic_read(&call->usage);
ASSERTCMP(n, >=, 1);
if (rxrpc_queue_work(&call->processor))
trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL);
else
rxrpc_put_call(call, rxrpc_call_put_noqueue);
return true;
}
/*
* Note the re-emergence of a call.
*/
void rxrpc_see_call(struct rxrpc_call *call)
{
const void *here = __builtin_return_address(0);
if (call) {
int n = atomic_read(&call->usage);
trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL);
}
}
/*
* Note the addition of a ref on a call.
*/
void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
{
const void *here = __builtin_return_address(0);
int n = atomic_inc_return(&call->usage);
trace_rxrpc_call(call, op, n, here, NULL);
}
/*
* Detach a call from its owning socket.
*/
void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
{
struct rxrpc_connection *conn = call->conn;
bool put = false;
int i;
_enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
rxrpc_see_call(call);
spin_lock_bh(&call->lock);
if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
BUG();
spin_unlock_bh(&call->lock);
del_timer_sync(&call->timer);
/* Make sure we don't get any more notifications */
write_lock_bh(&rx->recvmsg_lock);
if (!list_empty(&call->recvmsg_link)) {
_debug("unlinking once-pending call %p { e=%lx f=%lx }",
call, call->events, call->flags);
list_del(&call->recvmsg_link);
put = true;
}
/* list_empty() must return false in rxrpc_notify_socket() */
call->recvmsg_link.next = NULL;
call->recvmsg_link.prev = NULL;
write_unlock_bh(&rx->recvmsg_lock);
if (put)
rxrpc_put_call(call, rxrpc_call_put);
write_lock(&rx->call_lock);
if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
rb_erase(&call->sock_node, &rx->calls);
memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
rxrpc_put_call(call, rxrpc_call_put_userid);
}
list_del(&call->sock_link);
write_unlock(&rx->call_lock);
_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
if (conn)
rxrpc_disconnect_call(call);
for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
rxrpc_free_skb(call->rxtx_buffer[i]);
call->rxtx_buffer[i] = NULL;
}
/* We have to release the prealloc backlog ref */
if (rxrpc_is_service_call(call))
rxrpc_put_call(call, rxrpc_call_put);
_leave("");
}
/*
* release all the calls associated with a socket
*/
void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
{
struct rxrpc_call *call;
_enter("%p", rx);
while (!list_empty(&rx->sock_calls)) {
call = list_entry(rx->sock_calls.next,
struct rxrpc_call, sock_link);
rxrpc_get_call(call, rxrpc_call_got);
rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, ECONNRESET);
rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
rxrpc_release_call(rx, call);
rxrpc_put_call(call, rxrpc_call_put);
}
_leave("");
}
/*
* release a call
*/
void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
{
const void *here = __builtin_return_address(0);
int n;
ASSERT(call != NULL);
n = atomic_dec_return(&call->usage);
trace_rxrpc_call(call, op, n, here, NULL);
ASSERTCMP(n, >=, 0);
if (n == 0) {
_debug("call %d dead", call->debug_id);
ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
write_lock(&rxrpc_call_lock);
list_del_init(&call->link);
write_unlock(&rxrpc_call_lock);
rxrpc_cleanup_call(call);
}
}
/*
* Final call destruction under RCU.
*/
static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
{
struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
rxrpc_put_peer(call->peer);
kfree(call->rxtx_buffer);
kfree(call->rxtx_annotations);
kmem_cache_free(rxrpc_call_jar, call);
}
/*
* clean up a call
*/
void rxrpc_cleanup_call(struct rxrpc_call *call)
{
int i;
_net("DESTROY CALL %d", call->debug_id);
memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
del_timer_sync(&call->timer);
ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
ASSERTCMP(call->conn, ==, NULL);
/* Clean up the Rx/Tx buffer */
for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++)
rxrpc_free_skb(call->rxtx_buffer[i]);
rxrpc_free_skb(call->tx_pending);
call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
}
/*
* Make sure that all calls are gone.
*/
void __exit rxrpc_destroy_all_calls(void)
{
struct rxrpc_call *call;
_enter("");
if (list_empty(&rxrpc_calls))
return;
write_lock(&rxrpc_call_lock);
while (!list_empty(&rxrpc_calls)) {
call = list_entry(rxrpc_calls.next, struct rxrpc_call, link);
_debug("Zapping call %p", call);
rxrpc_see_call(call);
list_del_init(&call->link);
pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
call, atomic_read(&call->usage),
rxrpc_call_states[call->state],
call->flags, call->events);
write_unlock(&rxrpc_call_lock);
cond_resched();
write_lock(&rxrpc_call_lock);
}
write_unlock(&rxrpc_call_lock);
}