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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259/* * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved. * * This software is available to you under a choice of one of two * licenses. You may choose to be licensed under the terms of the GNU * General Public License (GPL) Version 2, available from the file * COPYING in the main directory of this source tree, or the * OpenIB.org BSD license below: * * Redistribution and use in source and binary forms, with or * without modification, are permitted provided that the following * conditions are met: * * - Redistributions of source code must retain the above * copyright notice, this list of conditions and the following * disclaimer. * * - Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials * provided with the distribution. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. * */#include <linux/kernel.h>#include <linux/slab.h>#include <linux/in.h>#include <net/net_namespace.h>#include <net/netns/generic.h>#include <linux/ipv6.h>
#include "rds_single_path.h"#include "rds.h"#include "loop.h"
static DEFINE_SPINLOCK(loop_conns_lock);static LIST_HEAD(loop_conns);static atomic_t rds_loop_unloading = ATOMIC_INIT(0);
static void rds_loop_set_unloading(void){ atomic_set(&rds_loop_unloading, 1);}
static bool rds_loop_is_unloading(struct rds_connection *conn){ return atomic_read(&rds_loop_unloading) != 0;}
/* * This 'loopback' transport is a special case for flows that originate * and terminate on the same machine. * * Connection build-up notices if the destination address is thought of * as a local address by a transport. At that time it decides to use the * loopback transport instead of the bound transport of the sending socket. * * The loopback transport's sending path just hands the sent rds_message * straight to the receiving path via an embedded rds_incoming. */
/* * Usually a message transits both the sender and receiver's conns as it * flows to the receiver. In the loopback case, though, the receive path * is handed the sending conn so the sense of the addresses is reversed. */static int rds_loop_xmit(struct rds_connection *conn, struct rds_message *rm, unsigned int hdr_off, unsigned int sg, unsigned int off){ struct scatterlist *sgp = &rm->data.op_sg[sg]; int ret = sizeof(struct rds_header) + be32_to_cpu(rm->m_inc.i_hdr.h_len);
/* Do not send cong updates to loopback */ if (rm->m_inc.i_hdr.h_flags & RDS_FLAG_CONG_BITMAP) { rds_cong_map_updated(conn->c_fcong, ~(u64) 0); ret = min_t(int, ret, sgp->length - conn->c_xmit_data_off); goto out; }
BUG_ON(hdr_off || sg || off);
/* rds_send_queue_rm() stored the connection path in this embedded * inc; use the path init so the re-initialization keeps the field * valid instead of discarding it. */ rds_inc_path_init(&rm->m_inc, &conn->c_path[0], &conn->c_laddr); /* For the embedded inc. Matching put is in loop_inc_free() */ rds_message_addref(rm);
rds_recv_incoming(conn, &conn->c_laddr, &conn->c_faddr, &rm->m_inc, GFP_KERNEL);
rds_send_drop_acked(conn, be64_to_cpu(rm->m_inc.i_hdr.h_sequence), NULL);
rds_inc_put(&rm->m_inc);out: return ret;}
/* * See rds_loop_xmit(). Since our inc is embedded in the rm, we * make sure the rm lives at least until the inc is done. */static void rds_loop_inc_free(struct rds_incoming *inc){ struct rds_message *rm = container_of(inc, struct rds_message, m_inc);
rds_message_put(rm);}
/* we need to at least give the thread something to succeed */static int rds_loop_recv_path(struct rds_conn_path *cp){ return 0;}
struct rds_loop_connection { struct list_head loop_node; struct rds_connection *conn;};
/* * Even the loopback transport needs to keep track of its connections, * so it can call rds_conn_destroy() on them on exit. N.B. there are * 1+ loopback addresses (127.*.*.*) so it's not a bug to have * multiple loopback conns allocated, although rather useless. */static int rds_loop_conn_alloc(struct rds_connection *conn, gfp_t gfp){ struct rds_loop_connection *lc; unsigned long flags;
lc = kzalloc_obj(struct rds_loop_connection, gfp); if (!lc) return -ENOMEM;
INIT_LIST_HEAD(&lc->loop_node); lc->conn = conn; conn->c_transport_data = lc;
spin_lock_irqsave(&loop_conns_lock, flags); list_add_tail(&lc->loop_node, &loop_conns); spin_unlock_irqrestore(&loop_conns_lock, flags);
return 0;}
static void rds_loop_conn_free(void *arg){ struct rds_loop_connection *lc = arg; unsigned long flags;
rdsdebug("lc %p\n", lc); spin_lock_irqsave(&loop_conns_lock, flags); list_del(&lc->loop_node); spin_unlock_irqrestore(&loop_conns_lock, flags); kfree(lc);}
static int rds_loop_conn_path_connect(struct rds_conn_path *cp){ rds_connect_complete(cp->cp_conn); return 0;}
static void rds_loop_conn_path_shutdown(struct rds_conn_path *cp){}
void rds_loop_exit(void){ struct rds_loop_connection *lc, *_lc; LIST_HEAD(tmp_list);
rds_loop_set_unloading(); synchronize_rcu(); /* avoid calling conn_destroy with irqs off */ spin_lock_irq(&loop_conns_lock); list_splice(&loop_conns, &tmp_list); INIT_LIST_HEAD(&loop_conns); spin_unlock_irq(&loop_conns_lock);
list_for_each_entry_safe(lc, _lc, &tmp_list, loop_node) { WARN_ON(lc->conn->c_passive); rds_conn_destroy(lc->conn); }}
static void rds_loop_kill_conns(struct net *net){ struct rds_loop_connection *lc, *_lc; LIST_HEAD(tmp_list);
spin_lock_irq(&loop_conns_lock); list_for_each_entry_safe(lc, _lc, &loop_conns, loop_node) { struct net *c_net = read_pnet(&lc->conn->c_net);
if (net != c_net) continue; list_move_tail(&lc->loop_node, &tmp_list); } spin_unlock_irq(&loop_conns_lock);
list_for_each_entry_safe(lc, _lc, &tmp_list, loop_node) { WARN_ON(lc->conn->c_passive); rds_conn_destroy(lc->conn); }}
static void __net_exit rds_loop_exit_net(struct net *net){ rds_loop_kill_conns(net);}
static struct pernet_operations rds_loop_net_ops = { .exit = rds_loop_exit_net,};
int rds_loop_net_init(void){ return register_pernet_device(&rds_loop_net_ops);}
void rds_loop_net_exit(void){ unregister_pernet_device(&rds_loop_net_ops);}
/* * This is missing .xmit_* because loop doesn't go through generic * rds_send_xmit() and doesn't call rds_recv_incoming(). .listen_stop and * .laddr_check are missing because transport.c doesn't iterate over * rds_loop_transport. */struct rds_transport rds_loop_transport = { .xmit = rds_loop_xmit, .recv_path = rds_loop_recv_path, .conn_alloc = rds_loop_conn_alloc, .conn_free = rds_loop_conn_free, .conn_path_connect = rds_loop_conn_path_connect, .conn_path_shutdown = rds_loop_conn_path_shutdown, .inc_copy_to_user = rds_message_inc_copy_to_user, .inc_free = rds_loop_inc_free, .t_name = "loopback", .t_type = RDS_TRANS_LOOP, .t_unloading = rds_loop_is_unloading,};