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-rw-r--r--net/rxrpc/ar-connection.c895
1 files changed, 895 insertions, 0 deletions
diff --git a/net/rxrpc/ar-connection.c b/net/rxrpc/ar-connection.c
new file mode 100644
index 000000000000..01eb33c30571
--- /dev/null
+++ b/net/rxrpc/ar-connection.c
@@ -0,0 +1,895 @@
+/* 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/net.h>
+#include <linux/skbuff.h>
+#include <linux/crypto.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static void rxrpc_connection_reaper(struct work_struct *work);
+
+LIST_HEAD(rxrpc_connections);
+DEFINE_RWLOCK(rxrpc_connection_lock);
+static unsigned long rxrpc_connection_timeout = 10 * 60;
+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, ntohl(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->debug_id);
+ 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 (IS_ERR(conn)) {
+ _leave(" = %ld", PTR_ERR(conn));
+ return PTR_ERR(conn);
+ }
+
+ 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;
+ 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;
+ }
+
+ /* 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->avail_calls == 0)
+ list_move(&conn->bundle_link,
+ &bundle->busy_conns);
+ 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);
+ 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 (IS_ERR(candidate)) {
+ _leave(" = %ld", PTR_ERR(candidate));
+ return PTR_ERR(candidate);
+ }
+
+ 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(rx->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;
+ 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));
+
+ 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 & __constant_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 = xtime.tv_sec;
+ if (atomic_dec_and_test(&conn->usage)) {
+ _debug("zombie");
+ schedule_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
+ */
+void rxrpc_connection_reaper(struct work_struct *work)
+{
+ struct rxrpc_connection *conn, *_p;
+ unsigned long now, earliest, reap_time;
+
+ LIST_HEAD(graveyard);
+
+ _enter("");
+
+ now = xtime.tv_sec;
+ 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_timeout;
+
+ 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);
+ schedule_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_timeout = 0;
+ cancel_delayed_work(&rxrpc_connection_reap);
+ schedule_delayed_work(&rxrpc_connection_reap, 0);
+
+ _leave("");
+}

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