diff options
Diffstat (limited to 'kernel/net/rxrpc/ar-connection.c')
| -rw-r--r-- | kernel/net/rxrpc/ar-connection.c | 928 |
1 files changed, 928 insertions, 0 deletions
diff --git a/kernel/net/rxrpc/ar-connection.c b/kernel/net/rxrpc/ar-connection.c new file mode 100644 index 000000000..6631f4f1e --- /dev/null +++ b/kernel/net/rxrpc/ar-connection.c @@ -0,0 +1,928 @@ +/* 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. + */ + +#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 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 client connection bundle + */ +static struct rxrpc_conn_bundle *rxrpc_alloc_bundle(gfp_t gfp) +{ + struct rxrpc_conn_bundle *bundle; + + _enter(""); + + bundle = kzalloc(sizeof(struct rxrpc_conn_bundle), gfp); + if (bundle) { + INIT_LIST_HEAD(&bundle->unused_conns); + INIT_LIST_HEAD(&bundle->avail_conns); + INIT_LIST_HEAD(&bundle->busy_conns); + init_waitqueue_head(&bundle->chanwait); + atomic_set(&bundle->usage, 1); + } + + _leave(" = %p", bundle); + return bundle; +} + +/* + * compare bundle parameters with what we're looking for + * - return -ve, 0 or +ve + */ +static inline +int rxrpc_cmp_bundle(const struct rxrpc_conn_bundle *bundle, + struct key *key, __be16 service_id) +{ + return (bundle->service_id - service_id) ?: + ((unsigned long) bundle->key - (unsigned long) key); +} + +/* + * get bundle of client connections that a client socket can make use of + */ +struct rxrpc_conn_bundle *rxrpc_get_bundle(struct rxrpc_sock *rx, + struct rxrpc_transport *trans, + struct key *key, + __be16 service_id, + gfp_t gfp) +{ + struct rxrpc_conn_bundle *bundle, *candidate; + struct rb_node *p, *parent, **pp; + + _enter("%p{%x},%x,%hx,", + rx, key_serial(key), trans->debug_id, ntohs(service_id)); + + if (rx->trans == trans && rx->bundle) { + atomic_inc(&rx->bundle->usage); + return rx->bundle; + } + + /* search the extant bundles first for one that matches the specified + * user ID */ + spin_lock(&trans->client_lock); + + p = trans->bundles.rb_node; + while (p) { + bundle = rb_entry(p, struct rxrpc_conn_bundle, node); + + if (rxrpc_cmp_bundle(bundle, key, service_id) < 0) + p = p->rb_left; + else if (rxrpc_cmp_bundle(bundle, key, service_id) > 0) + p = p->rb_right; + else + goto found_extant_bundle; + } + + spin_unlock(&trans->client_lock); + + /* not yet present - create a candidate for a new record and then + * redo the search */ + candidate = rxrpc_alloc_bundle(gfp); + if (!candidate) { + _leave(" = -ENOMEM"); + return ERR_PTR(-ENOMEM); + } + + candidate->key = key_get(key); + candidate->service_id = service_id; + + spin_lock(&trans->client_lock); + + pp = &trans->bundles.rb_node; + parent = NULL; + while (*pp) { + parent = *pp; + bundle = rb_entry(parent, struct rxrpc_conn_bundle, node); + + if (rxrpc_cmp_bundle(bundle, key, service_id) < 0) + pp = &(*pp)->rb_left; + else if (rxrpc_cmp_bundle(bundle, key, service_id) > 0) + pp = &(*pp)->rb_right; + else + goto found_extant_second; + } + + /* second search also failed; add the new bundle */ + bundle = candidate; + candidate = NULL; + + rb_link_node(&bundle->node, parent, pp); + rb_insert_color(&bundle->node, &trans->bundles); + spin_unlock(&trans->client_lock); + _net("BUNDLE new on trans %d", trans->debug_id); + if (!rx->bundle && rx->sk.sk_state == RXRPC_CLIENT_CONNECTED) { + atomic_inc(&bundle->usage); + rx->bundle = bundle; + } + _leave(" = %p [new]", bundle); + return bundle; + + /* we found the bundle in the list immediately */ +found_extant_bundle: + atomic_inc(&bundle->usage); + spin_unlock(&trans->client_lock); + _net("BUNDLE old on trans %d", trans->debug_id); + if (!rx->bundle && rx->sk.sk_state == RXRPC_CLIENT_CONNECTED) { + atomic_inc(&bundle->usage); + rx->bundle = bundle; + } + _leave(" = %p [extant %d]", bundle, atomic_read(&bundle->usage)); + return bundle; + + /* we found the bundle on the second time through the list */ +found_extant_second: + atomic_inc(&bundle->usage); + spin_unlock(&trans->client_lock); + kfree(candidate); + _net("BUNDLE old2 on trans %d", trans->debug_id); + if (!rx->bundle && rx->sk.sk_state == RXRPC_CLIENT_CONNECTED) { + atomic_inc(&bundle->usage); + rx->bundle = bundle; + } + _leave(" = %p [second %d]", bundle, atomic_read(&bundle->usage)); + return bundle; +} + +/* + * release a bundle + */ +void rxrpc_put_bundle(struct rxrpc_transport *trans, + struct rxrpc_conn_bundle *bundle) +{ + _enter("%p,%p{%d}",trans, bundle, atomic_read(&bundle->usage)); + + if (atomic_dec_and_lock(&bundle->usage, &trans->client_lock)) { + _debug("Destroy bundle"); + rb_erase(&bundle->node, &trans->bundles); + spin_unlock(&trans->client_lock); + ASSERT(list_empty(&bundle->unused_conns)); + ASSERT(list_empty(&bundle->avail_conns)); + ASSERT(list_empty(&bundle->busy_conns)); + ASSERTCMP(bundle->num_conns, ==, 0); + key_put(bundle->key); + kfree(bundle); + } + + _leave(""); +} + +/* + * 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) { + INIT_WORK(&conn->processor, &rxrpc_process_connection); + INIT_LIST_HEAD(&conn->bundle_link); + conn->calls = RB_ROOT; + skb_queue_head_init(&conn->rx_queue); + rwlock_init(&conn->lock); + spin_lock_init(&conn->state_lock); + atomic_set(&conn->usage, 1); + conn->debug_id = atomic_inc_return(&rxrpc_debug_id); + conn->avail_calls = RXRPC_MAXCALLS; + conn->size_align = 4; + conn->header_size = sizeof(struct rxrpc_header); + } + + _leave(" = %p{%d}", conn, conn ? conn->debug_id : 0); + return conn; +} + +/* + * assign a connection ID to a connection and add it to the transport's + * connection lookup tree + * - called with transport client lock held + */ +static void rxrpc_assign_connection_id(struct rxrpc_connection *conn) +{ + struct rxrpc_connection *xconn; + struct rb_node *parent, **p; + __be32 epoch; + u32 real_conn_id; + + _enter(""); + + epoch = conn->epoch; + + write_lock_bh(&conn->trans->conn_lock); + + conn->trans->conn_idcounter += RXRPC_CID_INC; + if (conn->trans->conn_idcounter < RXRPC_CID_INC) + conn->trans->conn_idcounter = RXRPC_CID_INC; + real_conn_id = conn->trans->conn_idcounter; + +attempt_insertion: + parent = NULL; + p = &conn->trans->client_conns.rb_node; + + while (*p) { + parent = *p; + xconn = rb_entry(parent, struct rxrpc_connection, node); + + if (epoch < xconn->epoch) + p = &(*p)->rb_left; + else if (epoch > xconn->epoch) + p = &(*p)->rb_right; + else if (real_conn_id < xconn->real_conn_id) + p = &(*p)->rb_left; + else if (real_conn_id > xconn->real_conn_id) + p = &(*p)->rb_right; + else + goto id_exists; + } + + /* we've found a suitable hole - arrange for this connection to occupy + * it */ + rb_link_node(&conn->node, parent, p); + rb_insert_color(&conn->node, &conn->trans->client_conns); + + conn->real_conn_id = real_conn_id; + conn->cid = htonl(real_conn_id); + write_unlock_bh(&conn->trans->conn_lock); + _leave(" [CONNID %x CID %x]", real_conn_id, ntohl(conn->cid)); + return; + + /* we found a connection with the proposed ID - walk the tree from that + * point looking for the next unused ID */ +id_exists: + for (;;) { + real_conn_id += RXRPC_CID_INC; + if (real_conn_id < RXRPC_CID_INC) { + real_conn_id = RXRPC_CID_INC; + conn->trans->conn_idcounter = real_conn_id; + goto attempt_insertion; + } + + parent = rb_next(parent); + if (!parent) + goto attempt_insertion; + + xconn = rb_entry(parent, struct rxrpc_connection, node); + if (epoch < xconn->epoch || + real_conn_id < xconn->real_conn_id) + goto attempt_insertion; + } +} + +/* + * 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); +} + +/* + * connect a call on an exclusive connection + */ +static int rxrpc_connect_exclusive(struct rxrpc_sock *rx, + struct rxrpc_transport *trans, + __be16 service_id, + struct rxrpc_call *call, + gfp_t gfp) +{ + struct rxrpc_connection *conn; + int chan, ret; + + _enter(""); + + conn = rx->conn; + if (!conn) { + /* not yet present - create a candidate for a new connection + * and then redo the check */ + conn = rxrpc_alloc_connection(gfp); + if (!conn) { + _leave(" = -ENOMEM"); + return -ENOMEM; + } + + conn->trans = trans; + conn->bundle = NULL; + conn->service_id = service_id; + conn->epoch = rxrpc_epoch; + conn->in_clientflag = 0; + conn->out_clientflag = RXRPC_CLIENT_INITIATED; + conn->cid = 0; + conn->state = RXRPC_CONN_CLIENT; + conn->avail_calls = RXRPC_MAXCALLS - 1; + conn->security_level = rx->min_sec_level; + conn->key = key_get(rx->key); + + ret = rxrpc_init_client_conn_security(conn); + if (ret < 0) { + key_put(conn->key); + kfree(conn); + _leave(" = %d [key]", ret); + return ret; + } + + write_lock_bh(&rxrpc_connection_lock); + list_add_tail(&conn->link, &rxrpc_connections); + write_unlock_bh(&rxrpc_connection_lock); + + spin_lock(&trans->client_lock); + atomic_inc(&trans->usage); + + _net("CONNECT EXCL new %d on TRANS %d", + conn->debug_id, conn->trans->debug_id); + + rxrpc_assign_connection_id(conn); + rx->conn = conn; + } else { + spin_lock(&trans->client_lock); + } + + /* we've got a connection with a free channel and we can now attach the + * call to it + * - we're holding the transport's client lock + * - we're holding a reference on the connection + */ + for (chan = 0; chan < RXRPC_MAXCALLS; chan++) + if (!conn->channels[chan]) + goto found_channel; + goto no_free_channels; + +found_channel: + atomic_inc(&conn->usage); + conn->channels[chan] = call; + call->conn = conn; + call->channel = chan; + call->cid = conn->cid | htonl(chan); + call->call_id = htonl(++conn->call_counter); + + _net("CONNECT client on conn %d chan %d as call %x", + conn->debug_id, chan, ntohl(call->call_id)); + + spin_unlock(&trans->client_lock); + + rxrpc_add_call_ID_to_conn(conn, call); + _leave(" = 0"); + return 0; + +no_free_channels: + spin_unlock(&trans->client_lock); + _leave(" = -ENOSR"); + return -ENOSR; +} + +/* + * find a connection for a call + * - called in process context with IRQs enabled + */ +int rxrpc_connect_call(struct rxrpc_sock *rx, + struct rxrpc_transport *trans, + struct rxrpc_conn_bundle *bundle, + struct rxrpc_call *call, + gfp_t gfp) +{ + struct rxrpc_connection *conn, *candidate; + int chan, ret; + + DECLARE_WAITQUEUE(myself, current); + + _enter("%p,%lx,", rx, call->user_call_ID); + + if (test_bit(RXRPC_SOCK_EXCLUSIVE_CONN, &rx->flags)) + return rxrpc_connect_exclusive(rx, trans, bundle->service_id, + call, gfp); + + spin_lock(&trans->client_lock); + for (;;) { + /* see if the bundle has a call slot available */ + if (!list_empty(&bundle->avail_conns)) { + _debug("avail"); + conn = list_entry(bundle->avail_conns.next, + struct rxrpc_connection, + bundle_link); + if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) { + list_del_init(&conn->bundle_link); + bundle->num_conns--; + continue; + } + if (--conn->avail_calls == 0) + list_move(&conn->bundle_link, + &bundle->busy_conns); + ASSERTCMP(conn->avail_calls, <, RXRPC_MAXCALLS); + ASSERT(conn->channels[0] == NULL || + conn->channels[1] == NULL || + conn->channels[2] == NULL || + conn->channels[3] == NULL); + atomic_inc(&conn->usage); + break; + } + + if (!list_empty(&bundle->unused_conns)) { + _debug("unused"); + conn = list_entry(bundle->unused_conns.next, + struct rxrpc_connection, + bundle_link); + if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) { + list_del_init(&conn->bundle_link); + bundle->num_conns--; + continue; + } + ASSERTCMP(conn->avail_calls, ==, RXRPC_MAXCALLS); + conn->avail_calls = RXRPC_MAXCALLS - 1; + ASSERT(conn->channels[0] == NULL && + conn->channels[1] == NULL && + conn->channels[2] == NULL && + conn->channels[3] == NULL); + atomic_inc(&conn->usage); + list_move(&conn->bundle_link, &bundle->avail_conns); + break; + } + + /* need to allocate a new connection */ + _debug("get new conn [%d]", bundle->num_conns); + + spin_unlock(&trans->client_lock); + + if (signal_pending(current)) + goto interrupted; + + if (bundle->num_conns >= 20) { + _debug("too many conns"); + + if (!(gfp & __GFP_WAIT)) { + _leave(" = -EAGAIN"); + return -EAGAIN; + } + + add_wait_queue(&bundle->chanwait, &myself); + for (;;) { + set_current_state(TASK_INTERRUPTIBLE); + if (bundle->num_conns < 20 || + !list_empty(&bundle->unused_conns) || + !list_empty(&bundle->avail_conns)) + break; + if (signal_pending(current)) + goto interrupted_dequeue; + schedule(); + } + remove_wait_queue(&bundle->chanwait, &myself); + __set_current_state(TASK_RUNNING); + spin_lock(&trans->client_lock); + continue; + } + + /* not yet present - create a candidate for a new connection and then + * redo the check */ + candidate = rxrpc_alloc_connection(gfp); + if (!candidate) { + _leave(" = -ENOMEM"); + return -ENOMEM; + } + + candidate->trans = trans; + candidate->bundle = bundle; + candidate->service_id = bundle->service_id; + candidate->epoch = rxrpc_epoch; + candidate->in_clientflag = 0; + candidate->out_clientflag = RXRPC_CLIENT_INITIATED; + candidate->cid = 0; + candidate->state = RXRPC_CONN_CLIENT; + candidate->avail_calls = RXRPC_MAXCALLS; + candidate->security_level = rx->min_sec_level; + candidate->key = key_get(bundle->key); + + ret = rxrpc_init_client_conn_security(candidate); + if (ret < 0) { + key_put(candidate->key); + kfree(candidate); + _leave(" = %d [key]", ret); + return ret; + } + + write_lock_bh(&rxrpc_connection_lock); + list_add_tail(&candidate->link, &rxrpc_connections); + write_unlock_bh(&rxrpc_connection_lock); + + spin_lock(&trans->client_lock); + + list_add(&candidate->bundle_link, &bundle->unused_conns); + bundle->num_conns++; + atomic_inc(&bundle->usage); + atomic_inc(&trans->usage); + + _net("CONNECT new %d on TRANS %d", + candidate->debug_id, candidate->trans->debug_id); + + rxrpc_assign_connection_id(candidate); + if (candidate->security) + candidate->security->prime_packet_security(candidate); + + /* leave the candidate lurking in zombie mode attached to the + * bundle until we're ready for it */ + rxrpc_put_connection(candidate); + candidate = NULL; + } + + /* we've got a connection with a free channel and we can now attach the + * call to it + * - we're holding the transport's client lock + * - we're holding a reference on the connection + * - we're holding a reference on the bundle + */ + for (chan = 0; chan < RXRPC_MAXCALLS; chan++) + if (!conn->channels[chan]) + goto found_channel; + ASSERT(conn->channels[0] == NULL || + conn->channels[1] == NULL || + conn->channels[2] == NULL || + conn->channels[3] == NULL); + BUG(); + +found_channel: + conn->channels[chan] = call; + call->conn = conn; + call->channel = chan; + call->cid = conn->cid | htonl(chan); + call->call_id = htonl(++conn->call_counter); + + _net("CONNECT client on conn %d chan %d as call %x", + conn->debug_id, chan, ntohl(call->call_id)); + + ASSERTCMP(conn->avail_calls, <, RXRPC_MAXCALLS); + spin_unlock(&trans->client_lock); + + rxrpc_add_call_ID_to_conn(conn, call); + + _leave(" = 0"); + return 0; + +interrupted_dequeue: + remove_wait_queue(&bundle->chanwait, &myself); + __set_current_state(TASK_RUNNING); +interrupted: + _leave(" = -ERESTARTSYS"); + return -ERESTARTSYS; +} + +/* + * get a record of an incoming connection + */ +struct rxrpc_connection * +rxrpc_incoming_connection(struct rxrpc_transport *trans, + struct rxrpc_header *hdr, + gfp_t gfp) +{ + struct rxrpc_connection *conn, *candidate = NULL; + struct rb_node *p, **pp; + const char *new = "old"; + __be32 epoch; + u32 conn_id; + + _enter(""); + + ASSERT(hdr->flags & RXRPC_CLIENT_INITIATED); + + epoch = hdr->epoch; + conn_id = ntohl(hdr->cid) & RXRPC_CIDMASK; + + /* search the connection list first */ + read_lock_bh(&trans->conn_lock); + + p = trans->server_conns.rb_node; + while (p) { + conn = rb_entry(p, struct rxrpc_connection, node); + + _debug("maybe %x", conn->real_conn_id); + + if (epoch < conn->epoch) + p = p->rb_left; + else if (epoch > conn->epoch) + p = p->rb_right; + else if (conn_id < conn->real_conn_id) + p = p->rb_left; + else if (conn_id > conn->real_conn_id) + p = p->rb_right; + else + goto found_extant_connection; + } + read_unlock_bh(&trans->conn_lock); + + /* not yet present - create a candidate for a new record and then + * redo the search */ + candidate = rxrpc_alloc_connection(gfp); + if (!candidate) { + _leave(" = -ENOMEM"); + return ERR_PTR(-ENOMEM); + } + + candidate->trans = trans; + candidate->epoch = hdr->epoch; + candidate->cid = hdr->cid & cpu_to_be32(RXRPC_CIDMASK); + candidate->service_id = hdr->serviceId; + candidate->security_ix = hdr->securityIndex; + candidate->in_clientflag = RXRPC_CLIENT_INITIATED; + candidate->out_clientflag = 0; + candidate->real_conn_id = conn_id; + candidate->state = RXRPC_CONN_SERVER; + if (candidate->service_id) + candidate->state = RXRPC_CONN_SERVER_UNSECURED; + + write_lock_bh(&trans->conn_lock); + + pp = &trans->server_conns.rb_node; + p = NULL; + while (*pp) { + p = *pp; + conn = rb_entry(p, struct rxrpc_connection, node); + + if (epoch < conn->epoch) + pp = &(*pp)->rb_left; + else if (epoch > conn->epoch) + pp = &(*pp)->rb_right; + else if (conn_id < conn->real_conn_id) + pp = &(*pp)->rb_left; + else if (conn_id > conn->real_conn_id) + 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->node, p, pp); + rb_insert_color(&conn->node, &trans->server_conns); + atomic_inc(&conn->trans->usage); + + write_unlock_bh(&trans->conn_lock); + + write_lock_bh(&rxrpc_connection_lock); + list_add_tail(&conn->link, &rxrpc_connections); + write_unlock_bh(&rxrpc_connection_lock); + + new = "new"; + +success: + _net("CONNECTION %s %d {%x}", new, conn->debug_id, conn->real_conn_id); + + _leave(" = %p {u=%d}", conn, atomic_read(&conn->usage)); + return conn; + + /* we found the connection in the list immediately */ +found_extant_connection: + if (hdr->securityIndex != conn->security_ix) { + read_unlock_bh(&trans->conn_lock); + goto security_mismatch; + } + atomic_inc(&conn->usage); + read_unlock_bh(&trans->conn_lock); + goto success; + + /* we found the connection on the second time through the list */ +found_extant_second: + if (hdr->securityIndex != conn->security_ix) { + write_unlock_bh(&trans->conn_lock); + goto security_mismatch; + } + atomic_inc(&conn->usage); + write_unlock_bh(&trans->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_transport *trans, + struct rxrpc_header *hdr) +{ + struct rxrpc_connection *conn; + struct rb_node *p; + __be32 epoch; + u32 conn_id; + + _enter(",{%x,%x}", ntohl(hdr->cid), hdr->flags); + + read_lock_bh(&trans->conn_lock); + + conn_id = ntohl(hdr->cid) & RXRPC_CIDMASK; + epoch = hdr->epoch; + + if (hdr->flags & RXRPC_CLIENT_INITIATED) + p = trans->server_conns.rb_node; + else + p = trans->client_conns.rb_node; + + while (p) { + conn = rb_entry(p, struct rxrpc_connection, node); + + _debug("maybe %x", conn->real_conn_id); + + if (epoch < conn->epoch) + p = p->rb_left; + else if (epoch > conn->epoch) + p = p->rb_right; + else if (conn_id < conn->real_conn_id) + p = p->rb_left; + else if (conn_id > conn->real_conn_id) + p = p->rb_right; + else + goto found; + } + + read_unlock_bh(&trans->conn_lock); + _leave(" = NULL"); + return NULL; + +found: + atomic_inc(&conn->usage); + read_unlock_bh(&trans->conn_lock); + _leave(" = %p", conn); + return conn; +} + +/* + * release a virtual connection + */ +void rxrpc_put_connection(struct rxrpc_connection *conn) +{ + _enter("%p{u=%d,d=%d}", + conn, atomic_read(&conn->usage), conn->debug_id); + + ASSERTCMP(atomic_read(&conn->usage), >, 0); + + conn->put_time = 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); + + if (conn->bundle) + rxrpc_put_bundle(conn->trans, conn->bundle); + + ASSERT(RB_EMPTY_ROOT(&conn->calls)); + rxrpc_purge_queue(&conn->rx_queue); + + rxrpc_clear_conn_security(conn); + rxrpc_put_transport(conn->trans); + kfree(conn); + _leave(""); +} + +/* + * reap dead connections + */ +static void rxrpc_connection_reaper(struct work_struct *work) +{ + struct rxrpc_connection *conn, *_p; + unsigned long now, earliest, reap_time; + + LIST_HEAD(graveyard); + + _enter(""); + + now = get_seconds(); + earliest = ULONG_MAX; + + write_lock_bh(&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; + + spin_lock(&conn->trans->client_lock); + write_lock(&conn->trans->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); + if (conn->out_clientflag) + rb_erase(&conn->node, + &conn->trans->client_conns); + else + rb_erase(&conn->node, + &conn->trans->server_conns); + if (conn->bundle) { + list_del_init(&conn->bundle_link); + conn->bundle->num_conns--; + } + + } else if (reap_time < earliest) { + earliest = reap_time; + } + + write_unlock(&conn->trans->conn_lock); + spin_unlock(&conn->trans->client_lock); + } + write_unlock_bh(&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(""); +} |