linux/net/rxrpc/conn_object.c
David Howells aa390bbe21 rxrpc: Kill off the rxrpc_transport struct
The rxrpc_transport struct is now redundant, given that the rxrpc_peer
struct is now per peer port rather than per peer host, so get rid of it.

Service connection lists are transferred to the rxrpc_peer struct, as is
the conn_lock.  Previous patches moved the client connection handling out
of the rxrpc_transport struct and discarded the connection bundling code.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 14:00:23 +01:00

687 lines
17 KiB
C

/* RxRPC virtual connection handler
*
* 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/module.h>
#include <linux/slab.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/crypto.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
/*
* Time till a connection expires after last use (in seconds).
*/
unsigned int rxrpc_connection_expiry = 10 * 60;
static void rxrpc_connection_reaper(struct work_struct *work);
LIST_HEAD(rxrpc_connections);
DEFINE_RWLOCK(rxrpc_connection_lock);
static DECLARE_DELAYED_WORK(rxrpc_connection_reap, rxrpc_connection_reaper);
/*
* allocate a new connection
*/
static struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
{
struct rxrpc_connection *conn;
_enter("");
conn = kzalloc(sizeof(struct rxrpc_connection), gfp);
if (conn) {
spin_lock_init(&conn->channel_lock);
init_waitqueue_head(&conn->channel_wq);
INIT_WORK(&conn->processor, &rxrpc_process_connection);
INIT_LIST_HEAD(&conn->link);
conn->calls = RB_ROOT;
skb_queue_head_init(&conn->rx_queue);
conn->security = &rxrpc_no_security;
rwlock_init(&conn->lock);
spin_lock_init(&conn->state_lock);
atomic_set(&conn->usage, 1);
conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
atomic_set(&conn->avail_chans, RXRPC_MAXCALLS);
conn->size_align = 4;
conn->header_size = sizeof(struct rxrpc_wire_header);
}
_leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
return conn;
}
/*
* add a call to a connection's call-by-ID tree
*/
static void rxrpc_add_call_ID_to_conn(struct rxrpc_connection *conn,
struct rxrpc_call *call)
{
struct rxrpc_call *xcall;
struct rb_node *parent, **p;
__be32 call_id;
write_lock_bh(&conn->lock);
call_id = call->call_id;
p = &conn->calls.rb_node;
parent = NULL;
while (*p) {
parent = *p;
xcall = rb_entry(parent, struct rxrpc_call, conn_node);
if (call_id < xcall->call_id)
p = &(*p)->rb_left;
else if (call_id > xcall->call_id)
p = &(*p)->rb_right;
else
BUG();
}
rb_link_node(&call->conn_node, parent, p);
rb_insert_color(&call->conn_node, &conn->calls);
write_unlock_bh(&conn->lock);
}
/*
* Allocate a client connection. The caller must take care to clear any
* padding bytes in *cp.
*/
static struct rxrpc_connection *
rxrpc_alloc_client_connection(struct rxrpc_conn_parameters *cp, gfp_t gfp)
{
struct rxrpc_connection *conn;
int ret;
_enter("");
conn = rxrpc_alloc_connection(gfp);
if (!conn) {
_leave(" = -ENOMEM");
return ERR_PTR(-ENOMEM);
}
conn->params = *cp;
conn->proto.local = cp->local;
conn->proto.epoch = rxrpc_epoch;
conn->proto.cid = 0;
conn->proto.in_clientflag = 0;
conn->proto.family = cp->peer->srx.transport.family;
conn->out_clientflag = RXRPC_CLIENT_INITIATED;
conn->state = RXRPC_CONN_CLIENT;
switch (conn->proto.family) {
case AF_INET:
conn->proto.addr_size = sizeof(conn->proto.ipv4_addr);
conn->proto.ipv4_addr = cp->peer->srx.transport.sin.sin_addr;
conn->proto.port = cp->peer->srx.transport.sin.sin_port;
break;
}
ret = rxrpc_get_client_connection_id(conn, gfp);
if (ret < 0)
goto error_0;
ret = rxrpc_init_client_conn_security(conn);
if (ret < 0)
goto error_1;
conn->security->prime_packet_security(conn);
write_lock(&rxrpc_connection_lock);
list_add_tail(&conn->link, &rxrpc_connections);
write_unlock(&rxrpc_connection_lock);
/* We steal the caller's peer ref. */
cp->peer = NULL;
rxrpc_get_local(conn->params.local);
key_get(conn->params.key);
_leave(" = %p", conn);
return conn;
error_1:
rxrpc_put_client_connection_id(conn);
error_0:
kfree(conn);
_leave(" = %d", ret);
return ERR_PTR(ret);
}
/*
* find a connection for a call
* - called in process context with IRQs enabled
*/
int rxrpc_connect_call(struct rxrpc_call *call,
struct rxrpc_conn_parameters *cp,
struct sockaddr_rxrpc *srx,
gfp_t gfp)
{
struct rxrpc_connection *conn, *candidate = NULL;
struct rxrpc_local *local = cp->local;
struct rb_node *p, **pp, *parent;
long diff;
int chan;
DECLARE_WAITQUEUE(myself, current);
_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
cp->peer = rxrpc_lookup_peer(cp->local, srx, gfp);
if (!cp->peer)
return -ENOMEM;
if (!cp->exclusive) {
/* Search for a existing client connection unless this is going
* to be a connection that's used exclusively for a single call.
*/
_debug("search 1");
spin_lock(&local->client_conns_lock);
p = local->client_conns.rb_node;
while (p) {
conn = rb_entry(p, struct rxrpc_connection, client_node);
#define cmp(X) ((long)conn->params.X - (long)cp->X)
diff = (cmp(peer) ?:
cmp(key) ?:
cmp(security_level));
if (diff < 0)
p = p->rb_left;
else if (diff > 0)
p = p->rb_right;
else
goto found_extant_conn;
}
spin_unlock(&local->client_conns_lock);
}
/* We didn't find a connection or we want an exclusive one. */
_debug("get new conn");
candidate = rxrpc_alloc_client_connection(cp, gfp);
if (!candidate) {
_leave(" = -ENOMEM");
return -ENOMEM;
}
if (cp->exclusive) {
/* Assign the call on an exclusive connection to channel 0 and
* don't add the connection to the endpoint's shareable conn
* lookup tree.
*/
_debug("exclusive chan 0");
conn = candidate;
atomic_set(&conn->avail_chans, RXRPC_MAXCALLS - 1);
spin_lock(&conn->channel_lock);
chan = 0;
goto found_channel;
}
/* We need to redo the search before attempting to add a new connection
* lest we race with someone else adding a conflicting instance.
*/
_debug("search 2");
spin_lock(&local->client_conns_lock);
pp = &local->client_conns.rb_node;
parent = NULL;
while (*pp) {
parent = *pp;
conn = rb_entry(parent, struct rxrpc_connection, client_node);
diff = (cmp(peer) ?:
cmp(key) ?:
cmp(security_level));
if (diff < 0)
pp = &(*pp)->rb_left;
else if (diff > 0)
pp = &(*pp)->rb_right;
else
goto found_extant_conn;
}
/* The second search also failed; simply add the new connection with
* the new call in channel 0. Note that we need to take the channel
* lock before dropping the client conn lock.
*/
_debug("new conn");
conn = candidate;
candidate = NULL;
rb_link_node(&conn->client_node, parent, pp);
rb_insert_color(&conn->client_node, &local->client_conns);
atomic_set(&conn->avail_chans, RXRPC_MAXCALLS - 1);
spin_lock(&conn->channel_lock);
spin_unlock(&local->client_conns_lock);
chan = 0;
found_channel:
_debug("found chan");
call->conn = conn;
call->channel = chan;
call->epoch = conn->proto.epoch;
call->cid = conn->proto.cid | chan;
call->call_id = ++conn->call_counter;
rcu_assign_pointer(conn->channels[chan], call);
_net("CONNECT call %d on conn %d", call->debug_id, conn->debug_id);
rxrpc_add_call_ID_to_conn(conn, call);
spin_unlock(&conn->channel_lock);
rxrpc_put_peer(cp->peer);
cp->peer = NULL;
_leave(" = %p {u=%d}", conn, atomic_read(&conn->usage));
return 0;
/* We found a suitable connection already in existence. Discard any
* candidate we may have allocated, and try to get a channel on this
* one.
*/
found_extant_conn:
_debug("found conn");
rxrpc_get_connection(conn);
spin_unlock(&local->client_conns_lock);
rxrpc_put_connection(candidate);
if (!atomic_add_unless(&conn->avail_chans, -1, 0)) {
if (!gfpflags_allow_blocking(gfp)) {
rxrpc_put_connection(conn);
_leave(" = -EAGAIN");
return -EAGAIN;
}
add_wait_queue(&conn->channel_wq, &myself);
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
if (atomic_add_unless(&conn->avail_chans, -1, 0))
break;
if (signal_pending(current))
goto interrupted;
schedule();
}
remove_wait_queue(&conn->channel_wq, &myself);
__set_current_state(TASK_RUNNING);
}
/* The connection allegedly now has a free channel and we can now
* attach the call to it.
*/
spin_lock(&conn->channel_lock);
for (chan = 0; chan < RXRPC_MAXCALLS; chan++)
if (!conn->channels[chan])
goto found_channel;
BUG();
interrupted:
remove_wait_queue(&conn->channel_wq, &myself);
__set_current_state(TASK_RUNNING);
rxrpc_put_connection(conn);
rxrpc_put_peer(cp->peer);
cp->peer = NULL;
_leave(" = -ERESTARTSYS");
return -ERESTARTSYS;
}
/*
* get a record of an incoming connection
*/
struct rxrpc_connection *rxrpc_incoming_connection(struct rxrpc_local *local,
struct rxrpc_peer *peer,
struct sk_buff *skb)
{
struct rxrpc_connection *conn, *candidate = NULL;
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
struct rb_node *p, **pp;
const char *new = "old";
__be32 epoch;
u32 cid;
_enter("");
ASSERT(sp->hdr.flags & RXRPC_CLIENT_INITIATED);
epoch = sp->hdr.epoch;
cid = sp->hdr.cid & RXRPC_CIDMASK;
/* search the connection list first */
read_lock_bh(&peer->conn_lock);
p = peer->service_conns.rb_node;
while (p) {
conn = rb_entry(p, struct rxrpc_connection, service_node);
_debug("maybe %x", conn->proto.cid);
if (epoch < conn->proto.epoch)
p = p->rb_left;
else if (epoch > conn->proto.epoch)
p = p->rb_right;
else if (cid < conn->proto.cid)
p = p->rb_left;
else if (cid > conn->proto.cid)
p = p->rb_right;
else
goto found_extant_connection;
}
read_unlock_bh(&peer->conn_lock);
/* not yet present - create a candidate for a new record and then
* redo the search */
candidate = rxrpc_alloc_connection(GFP_NOIO);
if (!candidate) {
_leave(" = -ENOMEM");
return ERR_PTR(-ENOMEM);
}
candidate->proto.local = local;
candidate->proto.epoch = sp->hdr.epoch;
candidate->proto.cid = sp->hdr.cid & RXRPC_CIDMASK;
candidate->proto.in_clientflag = RXRPC_CLIENT_INITIATED;
candidate->params.local = local;
candidate->params.peer = peer;
candidate->params.service_id = sp->hdr.serviceId;
candidate->security_ix = sp->hdr.securityIndex;
candidate->out_clientflag = 0;
candidate->state = RXRPC_CONN_SERVER;
if (candidate->params.service_id)
candidate->state = RXRPC_CONN_SERVER_UNSECURED;
write_lock_bh(&peer->conn_lock);
pp = &peer->service_conns.rb_node;
p = NULL;
while (*pp) {
p = *pp;
conn = rb_entry(p, struct rxrpc_connection, service_node);
if (epoch < conn->proto.epoch)
pp = &(*pp)->rb_left;
else if (epoch > conn->proto.epoch)
pp = &(*pp)->rb_right;
else if (cid < conn->proto.cid)
pp = &(*pp)->rb_left;
else if (cid > conn->proto.cid)
pp = &(*pp)->rb_right;
else
goto found_extant_second;
}
/* we can now add the new candidate to the list */
conn = candidate;
candidate = NULL;
rb_link_node(&conn->service_node, p, pp);
rb_insert_color(&conn->service_node, &peer->service_conns);
rxrpc_get_peer(peer);
rxrpc_get_local(local);
write_unlock_bh(&peer->conn_lock);
write_lock(&rxrpc_connection_lock);
list_add_tail(&conn->link, &rxrpc_connections);
write_unlock(&rxrpc_connection_lock);
new = "new";
success:
_net("CONNECTION %s %d {%x}", new, conn->debug_id, conn->proto.cid);
_leave(" = %p {u=%d}", conn, atomic_read(&conn->usage));
return conn;
/* we found the connection in the list immediately */
found_extant_connection:
if (sp->hdr.securityIndex != conn->security_ix) {
read_unlock_bh(&peer->conn_lock);
goto security_mismatch;
}
rxrpc_get_connection(conn);
read_unlock_bh(&peer->conn_lock);
goto success;
/* we found the connection on the second time through the list */
found_extant_second:
if (sp->hdr.securityIndex != conn->security_ix) {
write_unlock_bh(&peer->conn_lock);
goto security_mismatch;
}
rxrpc_get_connection(conn);
write_unlock_bh(&peer->conn_lock);
kfree(candidate);
goto success;
security_mismatch:
kfree(candidate);
_leave(" = -EKEYREJECTED");
return ERR_PTR(-EKEYREJECTED);
}
/*
* find a connection based on transport and RxRPC connection ID for an incoming
* packet
*/
struct rxrpc_connection *rxrpc_find_connection(struct rxrpc_local *local,
struct rxrpc_peer *peer,
struct sk_buff *skb)
{
struct rxrpc_connection *conn;
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
struct rb_node *p;
u32 epoch, cid;
_enter(",{%x,%x}", sp->hdr.cid, sp->hdr.flags);
read_lock_bh(&peer->conn_lock);
cid = sp->hdr.cid & RXRPC_CIDMASK;
epoch = sp->hdr.epoch;
if (sp->hdr.flags & RXRPC_CLIENT_INITIATED) {
p = peer->service_conns.rb_node;
while (p) {
conn = rb_entry(p, struct rxrpc_connection, service_node);
_debug("maybe %x", conn->proto.cid);
if (epoch < conn->proto.epoch)
p = p->rb_left;
else if (epoch > conn->proto.epoch)
p = p->rb_right;
else if (cid < conn->proto.cid)
p = p->rb_left;
else if (cid > conn->proto.cid)
p = p->rb_right;
else
goto found;
}
} else {
conn = idr_find(&rxrpc_client_conn_ids, cid >> RXRPC_CIDSHIFT);
if (conn && conn->proto.epoch == epoch)
goto found;
}
read_unlock_bh(&peer->conn_lock);
_leave(" = NULL");
return NULL;
found:
rxrpc_get_connection(conn);
read_unlock_bh(&peer->conn_lock);
_leave(" = %p", conn);
return conn;
}
/*
* Disconnect a call and clear any channel it occupies when that call
* terminates.
*/
void rxrpc_disconnect_call(struct rxrpc_call *call)
{
struct rxrpc_connection *conn = call->conn;
unsigned chan = call->channel;
_enter("%d,%d", conn->debug_id, call->channel);
if (conn->channels[chan] == call) {
rcu_assign_pointer(conn->channels[chan], NULL);
atomic_inc(&conn->avail_chans);
wake_up(&conn->channel_wq);
}
}
/*
* release a virtual connection
*/
void rxrpc_put_connection(struct rxrpc_connection *conn)
{
if (!conn)
return;
_enter("%p{u=%d,d=%d}",
conn, atomic_read(&conn->usage), conn->debug_id);
ASSERTCMP(atomic_read(&conn->usage), >, 0);
conn->put_time = ktime_get_seconds();
if (atomic_dec_and_test(&conn->usage)) {
_debug("zombie");
rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
}
_leave("");
}
/*
* destroy a virtual connection
*/
static void rxrpc_destroy_connection(struct rxrpc_connection *conn)
{
_enter("%p{%d}", conn, atomic_read(&conn->usage));
ASSERTCMP(atomic_read(&conn->usage), ==, 0);
_net("DESTROY CONN %d", conn->debug_id);
ASSERT(RB_EMPTY_ROOT(&conn->calls));
rxrpc_purge_queue(&conn->rx_queue);
conn->security->clear(conn);
key_put(conn->params.key);
key_put(conn->server_key);
rxrpc_put_peer(conn->params.peer);
rxrpc_put_local(conn->params.local);
kfree(conn);
_leave("");
}
/*
* reap dead connections
*/
static void rxrpc_connection_reaper(struct work_struct *work)
{
struct rxrpc_connection *conn, *_p;
struct rxrpc_peer *peer;
unsigned long now, earliest, reap_time;
LIST_HEAD(graveyard);
_enter("");
now = ktime_get_seconds();
earliest = ULONG_MAX;
write_lock(&rxrpc_connection_lock);
list_for_each_entry_safe(conn, _p, &rxrpc_connections, link) {
_debug("reap CONN %d { u=%d,t=%ld }",
conn->debug_id, atomic_read(&conn->usage),
(long) now - (long) conn->put_time);
if (likely(atomic_read(&conn->usage) > 0))
continue;
if (rxrpc_conn_is_client(conn)) {
struct rxrpc_local *local = conn->params.local;
spin_lock(&local->client_conns_lock);
reap_time = conn->put_time + rxrpc_connection_expiry;
if (atomic_read(&conn->usage) > 0) {
;
} else if (reap_time <= now) {
list_move_tail(&conn->link, &graveyard);
rxrpc_put_client_connection_id(conn);
rb_erase(&conn->client_node,
&local->client_conns);
} else if (reap_time < earliest) {
earliest = reap_time;
}
spin_unlock(&local->client_conns_lock);
} else {
peer = conn->params.peer;
write_lock_bh(&peer->conn_lock);
reap_time = conn->put_time + rxrpc_connection_expiry;
if (atomic_read(&conn->usage) > 0) {
;
} else if (reap_time <= now) {
list_move_tail(&conn->link, &graveyard);
rb_erase(&conn->service_node,
&peer->service_conns);
} else if (reap_time < earliest) {
earliest = reap_time;
}
write_unlock_bh(&peer->conn_lock);
}
}
write_unlock(&rxrpc_connection_lock);
if (earliest != ULONG_MAX) {
_debug("reschedule reaper %ld", (long) earliest - now);
ASSERTCMP(earliest, >, now);
rxrpc_queue_delayed_work(&rxrpc_connection_reap,
(earliest - now) * HZ);
}
/* then destroy all those pulled out */
while (!list_empty(&graveyard)) {
conn = list_entry(graveyard.next, struct rxrpc_connection,
link);
list_del_init(&conn->link);
ASSERTCMP(atomic_read(&conn->usage), ==, 0);
rxrpc_destroy_connection(conn);
}
_leave("");
}
/*
* preemptively destroy all the connection records rather than waiting for them
* to time out
*/
void __exit rxrpc_destroy_all_connections(void)
{
_enter("");
rxrpc_connection_expiry = 0;
cancel_delayed_work(&rxrpc_connection_reap);
rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
_leave("");
}