linux-kernel-test/net/tipc/port.c
Jon Paul Maloy 60120526c2 tipc: simplify connection congestion handling
As a consequence of the recently introduced serialized access
to the socket in commit 8d94168a761819d10252bab1f8de6d7b202c3baa
("tipc: same receive code path for connection protocol and data
messages") we can make a number of simplifications in the
detection and handling of connection congestion situations.

- We don't need to keep two counters, one for sent messages and one
  for acked messages. There is no longer any risk for races between
  acknowledge messages arriving in BH and data message sending
  running in user context. So we merge this into one counter,
  'sent_unacked', which is incremented at sending and subtracted
  from at acknowledge reception.

- We don't need to set the 'congested' field in tipc_port to
  true before we sent the message, and clear it when sending
  is successful. (As a matter of fact, it was never necessary;
  the field was set in link_schedule_port() before any wakeup
  could arrive anyway.)

- We keep the conditions for link congestion and connection connection
  congestion separated. There would otherwise be a risk that an arriving
  acknowledge message may wake up a user sleeping because of link
  congestion.

- We can simplify reception of acknowledge messages.

We also make some cosmetic/structural changes:

- We rename the 'congested' field to the more correct 'link_cong´.

- We rename 'conn_unacked' to 'rcv_unacked'

- We move the above mentioned fields from struct tipc_port to
  struct tipc_sock.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-27 12:50:56 -07:00

627 lines
16 KiB
C

/*
* net/tipc/port.c: TIPC port code
*
* Copyright (c) 1992-2007, 2014, Ericsson AB
* Copyright (c) 2004-2008, 2010-2013, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "core.h"
#include "config.h"
#include "port.h"
#include "name_table.h"
#include "socket.h"
/* Connection management: */
#define PROBING_INTERVAL 3600000 /* [ms] => 1 h */
#define MAX_REJECT_SIZE 1024
DEFINE_SPINLOCK(tipc_port_list_lock);
static LIST_HEAD(ports);
static void port_handle_node_down(unsigned long ref);
static struct sk_buff *port_build_self_abort_msg(struct tipc_port *, u32 err);
static struct sk_buff *port_build_peer_abort_msg(struct tipc_port *, u32 err);
static void port_timeout(unsigned long ref);
/**
* tipc_port_peer_msg - verify message was sent by connected port's peer
*
* Handles cases where the node's network address has changed from
* the default of <0.0.0> to its configured setting.
*/
int tipc_port_peer_msg(struct tipc_port *p_ptr, struct tipc_msg *msg)
{
u32 peernode;
u32 orignode;
if (msg_origport(msg) != tipc_port_peerport(p_ptr))
return 0;
orignode = msg_orignode(msg);
peernode = tipc_port_peernode(p_ptr);
return (orignode == peernode) ||
(!orignode && (peernode == tipc_own_addr)) ||
(!peernode && (orignode == tipc_own_addr));
}
/**
* tipc_port_mcast_xmit - send a multicast message to local and remote
* destinations
*/
int tipc_port_mcast_xmit(struct tipc_port *oport,
struct tipc_name_seq const *seq,
struct iovec const *msg_sect,
unsigned int len)
{
struct tipc_msg *hdr;
struct sk_buff *buf;
struct sk_buff *ibuf = NULL;
struct tipc_port_list dports = {0, NULL, };
int ext_targets;
int res;
/* Create multicast message */
hdr = &oport->phdr;
msg_set_type(hdr, TIPC_MCAST_MSG);
msg_set_lookup_scope(hdr, TIPC_CLUSTER_SCOPE);
msg_set_destport(hdr, 0);
msg_set_destnode(hdr, 0);
msg_set_nametype(hdr, seq->type);
msg_set_namelower(hdr, seq->lower);
msg_set_nameupper(hdr, seq->upper);
msg_set_hdr_sz(hdr, MCAST_H_SIZE);
res = tipc_msg_build(hdr, msg_sect, len, MAX_MSG_SIZE, &buf);
if (unlikely(!buf))
return res;
/* Figure out where to send multicast message */
ext_targets = tipc_nametbl_mc_translate(seq->type, seq->lower, seq->upper,
TIPC_NODE_SCOPE, &dports);
/* Send message to destinations (duplicate it only if necessary) */
if (ext_targets) {
if (dports.count != 0) {
ibuf = skb_copy(buf, GFP_ATOMIC);
if (ibuf == NULL) {
tipc_port_list_free(&dports);
kfree_skb(buf);
return -ENOMEM;
}
}
res = tipc_bclink_xmit(buf);
if ((res < 0) && (dports.count != 0))
kfree_skb(ibuf);
} else {
ibuf = buf;
}
if (res >= 0) {
if (ibuf)
tipc_port_mcast_rcv(ibuf, &dports);
} else {
tipc_port_list_free(&dports);
}
return res;
}
/**
* tipc_port_mcast_rcv - deliver multicast message to all destination ports
*
* If there is no port list, perform a lookup to create one
*/
void tipc_port_mcast_rcv(struct sk_buff *buf, struct tipc_port_list *dp)
{
struct tipc_msg *msg;
struct tipc_port_list dports = {0, NULL, };
struct tipc_port_list *item = dp;
int cnt = 0;
msg = buf_msg(buf);
/* Create destination port list, if one wasn't supplied */
if (dp == NULL) {
tipc_nametbl_mc_translate(msg_nametype(msg),
msg_namelower(msg),
msg_nameupper(msg),
TIPC_CLUSTER_SCOPE,
&dports);
item = dp = &dports;
}
/* Deliver a copy of message to each destination port */
if (dp->count != 0) {
msg_set_destnode(msg, tipc_own_addr);
if (dp->count == 1) {
msg_set_destport(msg, dp->ports[0]);
tipc_sk_rcv(buf);
tipc_port_list_free(dp);
return;
}
for (; cnt < dp->count; cnt++) {
int index = cnt % PLSIZE;
struct sk_buff *b = skb_clone(buf, GFP_ATOMIC);
if (b == NULL) {
pr_warn("Unable to deliver multicast message(s)\n");
goto exit;
}
if ((index == 0) && (cnt != 0))
item = item->next;
msg_set_destport(buf_msg(b), item->ports[index]);
tipc_sk_rcv(b);
}
}
exit:
kfree_skb(buf);
tipc_port_list_free(dp);
}
/* tipc_port_init - intiate TIPC port and lock it
*
* Returns obtained reference if initialization is successful, zero otherwise
*/
u32 tipc_port_init(struct tipc_port *p_ptr,
const unsigned int importance)
{
struct tipc_msg *msg;
u32 ref;
ref = tipc_ref_acquire(p_ptr, &p_ptr->lock);
if (!ref) {
pr_warn("Port registration failed, ref. table exhausted\n");
return 0;
}
p_ptr->max_pkt = MAX_PKT_DEFAULT;
p_ptr->ref = ref;
INIT_LIST_HEAD(&p_ptr->wait_list);
INIT_LIST_HEAD(&p_ptr->subscription.nodesub_list);
k_init_timer(&p_ptr->timer, (Handler)port_timeout, ref);
INIT_LIST_HEAD(&p_ptr->publications);
INIT_LIST_HEAD(&p_ptr->port_list);
/*
* Must hold port list lock while initializing message header template
* to ensure a change to node's own network address doesn't result
* in template containing out-dated network address information
*/
spin_lock_bh(&tipc_port_list_lock);
msg = &p_ptr->phdr;
tipc_msg_init(msg, importance, TIPC_NAMED_MSG, NAMED_H_SIZE, 0);
msg_set_origport(msg, ref);
list_add_tail(&p_ptr->port_list, &ports);
spin_unlock_bh(&tipc_port_list_lock);
return ref;
}
void tipc_port_destroy(struct tipc_port *p_ptr)
{
struct sk_buff *buf = NULL;
struct tipc_msg *msg = NULL;
u32 peer;
tipc_withdraw(p_ptr, 0, NULL);
spin_lock_bh(p_ptr->lock);
tipc_ref_discard(p_ptr->ref);
spin_unlock_bh(p_ptr->lock);
k_cancel_timer(&p_ptr->timer);
if (p_ptr->connected) {
buf = port_build_peer_abort_msg(p_ptr, TIPC_ERR_NO_PORT);
tipc_nodesub_unsubscribe(&p_ptr->subscription);
msg = buf_msg(buf);
peer = msg_destnode(msg);
tipc_link_xmit2(buf, peer, msg_link_selector(msg));
}
spin_lock_bh(&tipc_port_list_lock);
list_del(&p_ptr->port_list);
list_del(&p_ptr->wait_list);
spin_unlock_bh(&tipc_port_list_lock);
k_term_timer(&p_ptr->timer);
}
/*
* port_build_proto_msg(): create connection protocol message for port
*
* On entry the port must be locked and connected.
*/
static struct sk_buff *port_build_proto_msg(struct tipc_port *p_ptr,
u32 type, u32 ack)
{
struct sk_buff *buf;
struct tipc_msg *msg;
buf = tipc_buf_acquire(INT_H_SIZE);
if (buf) {
msg = buf_msg(buf);
tipc_msg_init(msg, CONN_MANAGER, type, INT_H_SIZE,
tipc_port_peernode(p_ptr));
msg_set_destport(msg, tipc_port_peerport(p_ptr));
msg_set_origport(msg, p_ptr->ref);
msg_set_msgcnt(msg, ack);
buf->next = NULL;
}
return buf;
}
static void port_timeout(unsigned long ref)
{
struct tipc_port *p_ptr = tipc_port_lock(ref);
struct sk_buff *buf = NULL;
struct tipc_msg *msg = NULL;
if (!p_ptr)
return;
if (!p_ptr->connected) {
tipc_port_unlock(p_ptr);
return;
}
/* Last probe answered ? */
if (p_ptr->probing_state == TIPC_CONN_PROBING) {
buf = port_build_self_abort_msg(p_ptr, TIPC_ERR_NO_PORT);
} else {
buf = port_build_proto_msg(p_ptr, CONN_PROBE, 0);
p_ptr->probing_state = TIPC_CONN_PROBING;
k_start_timer(&p_ptr->timer, p_ptr->probing_interval);
}
tipc_port_unlock(p_ptr);
msg = buf_msg(buf);
tipc_link_xmit2(buf, msg_destnode(msg), msg_link_selector(msg));
}
static void port_handle_node_down(unsigned long ref)
{
struct tipc_port *p_ptr = tipc_port_lock(ref);
struct sk_buff *buf = NULL;
struct tipc_msg *msg = NULL;
if (!p_ptr)
return;
buf = port_build_self_abort_msg(p_ptr, TIPC_ERR_NO_NODE);
tipc_port_unlock(p_ptr);
msg = buf_msg(buf);
tipc_link_xmit2(buf, msg_destnode(msg), msg_link_selector(msg));
}
static struct sk_buff *port_build_self_abort_msg(struct tipc_port *p_ptr, u32 err)
{
struct sk_buff *buf = port_build_peer_abort_msg(p_ptr, err);
if (buf) {
struct tipc_msg *msg = buf_msg(buf);
msg_swap_words(msg, 4, 5);
msg_swap_words(msg, 6, 7);
buf->next = NULL;
}
return buf;
}
static struct sk_buff *port_build_peer_abort_msg(struct tipc_port *p_ptr, u32 err)
{
struct sk_buff *buf;
struct tipc_msg *msg;
u32 imp;
if (!p_ptr->connected)
return NULL;
buf = tipc_buf_acquire(BASIC_H_SIZE);
if (buf) {
msg = buf_msg(buf);
memcpy(msg, &p_ptr->phdr, BASIC_H_SIZE);
msg_set_hdr_sz(msg, BASIC_H_SIZE);
msg_set_size(msg, BASIC_H_SIZE);
imp = msg_importance(msg);
if (imp < TIPC_CRITICAL_IMPORTANCE)
msg_set_importance(msg, ++imp);
msg_set_errcode(msg, err);
buf->next = NULL;
}
return buf;
}
static int port_print(struct tipc_port *p_ptr, char *buf, int len, int full_id)
{
struct publication *publ;
int ret;
if (full_id)
ret = tipc_snprintf(buf, len, "<%u.%u.%u:%u>:",
tipc_zone(tipc_own_addr),
tipc_cluster(tipc_own_addr),
tipc_node(tipc_own_addr), p_ptr->ref);
else
ret = tipc_snprintf(buf, len, "%-10u:", p_ptr->ref);
if (p_ptr->connected) {
u32 dport = tipc_port_peerport(p_ptr);
u32 destnode = tipc_port_peernode(p_ptr);
ret += tipc_snprintf(buf + ret, len - ret,
" connected to <%u.%u.%u:%u>",
tipc_zone(destnode),
tipc_cluster(destnode),
tipc_node(destnode), dport);
if (p_ptr->conn_type != 0)
ret += tipc_snprintf(buf + ret, len - ret,
" via {%u,%u}", p_ptr->conn_type,
p_ptr->conn_instance);
} else if (p_ptr->published) {
ret += tipc_snprintf(buf + ret, len - ret, " bound to");
list_for_each_entry(publ, &p_ptr->publications, pport_list) {
if (publ->lower == publ->upper)
ret += tipc_snprintf(buf + ret, len - ret,
" {%u,%u}", publ->type,
publ->lower);
else
ret += tipc_snprintf(buf + ret, len - ret,
" {%u,%u,%u}", publ->type,
publ->lower, publ->upper);
}
}
ret += tipc_snprintf(buf + ret, len - ret, "\n");
return ret;
}
struct sk_buff *tipc_port_get_ports(void)
{
struct sk_buff *buf;
struct tlv_desc *rep_tlv;
char *pb;
int pb_len;
struct tipc_port *p_ptr;
int str_len = 0;
buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
if (!buf)
return NULL;
rep_tlv = (struct tlv_desc *)buf->data;
pb = TLV_DATA(rep_tlv);
pb_len = ULTRA_STRING_MAX_LEN;
spin_lock_bh(&tipc_port_list_lock);
list_for_each_entry(p_ptr, &ports, port_list) {
spin_lock_bh(p_ptr->lock);
str_len += port_print(p_ptr, pb, pb_len, 0);
spin_unlock_bh(p_ptr->lock);
}
spin_unlock_bh(&tipc_port_list_lock);
str_len += 1; /* for "\0" */
skb_put(buf, TLV_SPACE(str_len));
TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
return buf;
}
void tipc_port_reinit(void)
{
struct tipc_port *p_ptr;
struct tipc_msg *msg;
spin_lock_bh(&tipc_port_list_lock);
list_for_each_entry(p_ptr, &ports, port_list) {
msg = &p_ptr->phdr;
msg_set_prevnode(msg, tipc_own_addr);
msg_set_orignode(msg, tipc_own_addr);
}
spin_unlock_bh(&tipc_port_list_lock);
}
void tipc_acknowledge(u32 ref, u32 ack)
{
struct tipc_port *p_ptr;
struct sk_buff *buf = NULL;
struct tipc_msg *msg;
p_ptr = tipc_port_lock(ref);
if (!p_ptr)
return;
if (p_ptr->connected)
buf = port_build_proto_msg(p_ptr, CONN_ACK, ack);
tipc_port_unlock(p_ptr);
if (!buf)
return;
msg = buf_msg(buf);
tipc_link_xmit2(buf, msg_destnode(msg), msg_link_selector(msg));
}
int tipc_publish(struct tipc_port *p_ptr, unsigned int scope,
struct tipc_name_seq const *seq)
{
struct publication *publ;
u32 key;
if (p_ptr->connected)
return -EINVAL;
key = p_ptr->ref + p_ptr->pub_count + 1;
if (key == p_ptr->ref)
return -EADDRINUSE;
publ = tipc_nametbl_publish(seq->type, seq->lower, seq->upper,
scope, p_ptr->ref, key);
if (publ) {
list_add(&publ->pport_list, &p_ptr->publications);
p_ptr->pub_count++;
p_ptr->published = 1;
return 0;
}
return -EINVAL;
}
int tipc_withdraw(struct tipc_port *p_ptr, unsigned int scope,
struct tipc_name_seq const *seq)
{
struct publication *publ;
struct publication *tpubl;
int res = -EINVAL;
if (!seq) {
list_for_each_entry_safe(publ, tpubl,
&p_ptr->publications, pport_list) {
tipc_nametbl_withdraw(publ->type, publ->lower,
publ->ref, publ->key);
}
res = 0;
} else {
list_for_each_entry_safe(publ, tpubl,
&p_ptr->publications, pport_list) {
if (publ->scope != scope)
continue;
if (publ->type != seq->type)
continue;
if (publ->lower != seq->lower)
continue;
if (publ->upper != seq->upper)
break;
tipc_nametbl_withdraw(publ->type, publ->lower,
publ->ref, publ->key);
res = 0;
break;
}
}
if (list_empty(&p_ptr->publications))
p_ptr->published = 0;
return res;
}
int tipc_port_connect(u32 ref, struct tipc_portid const *peer)
{
struct tipc_port *p_ptr;
int res;
p_ptr = tipc_port_lock(ref);
if (!p_ptr)
return -EINVAL;
res = __tipc_port_connect(ref, p_ptr, peer);
tipc_port_unlock(p_ptr);
return res;
}
/*
* __tipc_port_connect - connect to a remote peer
*
* Port must be locked.
*/
int __tipc_port_connect(u32 ref, struct tipc_port *p_ptr,
struct tipc_portid const *peer)
{
struct tipc_msg *msg;
int res = -EINVAL;
if (p_ptr->published || p_ptr->connected)
goto exit;
if (!peer->ref)
goto exit;
msg = &p_ptr->phdr;
msg_set_destnode(msg, peer->node);
msg_set_destport(msg, peer->ref);
msg_set_type(msg, TIPC_CONN_MSG);
msg_set_lookup_scope(msg, 0);
msg_set_hdr_sz(msg, SHORT_H_SIZE);
p_ptr->probing_interval = PROBING_INTERVAL;
p_ptr->probing_state = TIPC_CONN_OK;
p_ptr->connected = 1;
k_start_timer(&p_ptr->timer, p_ptr->probing_interval);
tipc_nodesub_subscribe(&p_ptr->subscription, peer->node,
(void *)(unsigned long)ref,
(net_ev_handler)port_handle_node_down);
res = 0;
exit:
p_ptr->max_pkt = tipc_node_get_mtu(peer->node, ref);
return res;
}
/*
* __tipc_disconnect - disconnect port from peer
*
* Port must be locked.
*/
int __tipc_port_disconnect(struct tipc_port *tp_ptr)
{
if (tp_ptr->connected) {
tp_ptr->connected = 0;
/* let timer expire on it's own to avoid deadlock! */
tipc_nodesub_unsubscribe(&tp_ptr->subscription);
return 0;
}
return -ENOTCONN;
}
/*
* tipc_port_disconnect(): Disconnect port form peer.
* This is a node local operation.
*/
int tipc_port_disconnect(u32 ref)
{
struct tipc_port *p_ptr;
int res;
p_ptr = tipc_port_lock(ref);
if (!p_ptr)
return -EINVAL;
res = __tipc_port_disconnect(p_ptr);
tipc_port_unlock(p_ptr);
return res;
}
/*
* tipc_port_shutdown(): Send a SHUTDOWN msg to peer and disconnect
*/
int tipc_port_shutdown(u32 ref)
{
struct tipc_msg *msg;
struct tipc_port *p_ptr;
struct sk_buff *buf = NULL;
p_ptr = tipc_port_lock(ref);
if (!p_ptr)
return -EINVAL;
buf = port_build_peer_abort_msg(p_ptr, TIPC_CONN_SHUTDOWN);
tipc_port_unlock(p_ptr);
msg = buf_msg(buf);
tipc_link_xmit2(buf, msg_destnode(msg), msg_link_selector(msg));
return tipc_port_disconnect(ref);
}