diff options
Diffstat (limited to 'net/rxrpc/conn_object.c')
| -rw-r--r-- | net/rxrpc/conn_object.c | 686 |
1 files changed, 686 insertions, 0 deletions
diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c new file mode 100644 index 000000000000..4bfad7cf96cb --- /dev/null +++ b/net/rxrpc/conn_object.c @@ -0,0 +1,686 @@ +/* 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(""); +} |