port.c

linux 内核源代码

/*
 * net/tipc/port.c: TIPC port code
 *
 * Copyright (c) 1992-2007, Ericsson AB
 * Copyright (c) 2004-2007, 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 "dbg.h"
#include "port.h"
#include "addr.h"
#include "link.h"
#include "node.h"
#include "name_table.h"
#include "user_reg.h"
#include "msg.h"
#include "bcast.h"

/* Connection management: */
#define PROBING_INTERVAL 3600000	/* [ms] => 1 h */
#define CONFIRMED 0
#define PROBING 1

#define MAX_REJECT_SIZE 1024

static struct sk_buff *msg_queue_head = NULL;
static struct sk_buff *msg_queue_tail = NULL;

DEFINE_SPINLOCK(tipc_port_list_lock);
static DEFINE_SPINLOCK(queue_lock);

static LIST_HEAD(ports);
static void port_handle_node_down(unsigned long ref);
static struct sk_buff* port_build_self_abort_msg(struct port *,u32 err);
static struct sk_buff* port_build_peer_abort_msg(struct port *,u32 err);
static void port_timeout(unsigned long ref);


static u32 port_peernode(struct port *p_ptr)
{
	return msg_destnode(&p_ptr->publ.phdr);
}

static u32 port_peerport(struct port *p_ptr)
{
	return msg_destport(&p_ptr->publ.phdr);
}

static u32 port_out_seqno(struct port *p_ptr)
{
	return msg_transp_seqno(&p_ptr->publ.phdr);
}

static void port_incr_out_seqno(struct port *p_ptr)
{
	struct tipc_msg *m = &p_ptr->publ.phdr;

	if (likely(!msg_routed(m)))
		return;
	msg_set_transp_seqno(m, (msg_transp_seqno(m) + 1));
}

/**
 * tipc_multicast - send a multicast message to local and remote destinations
 */

int tipc_multicast(u32 ref, struct tipc_name_seq const *seq, u32 domain,
		   u32 num_sect, struct iovec const *msg_sect)
{
	struct tipc_msg *hdr;
	struct sk_buff *buf;
	struct sk_buff *ibuf = NULL;
	struct port_list dports = {0, NULL, };
	struct port *oport = tipc_port_deref(ref);
	int ext_targets;
	int res;

	if (unlikely(!oport))
		return -EINVAL;

	/* Create multicast message */

	hdr = &oport->publ.phdr;
	msg_set_type(hdr, TIPC_MCAST_MSG);
	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 = msg_build(hdr, msg_sect, num_sect, MAX_MSG_SIZE,
			!oport->user_port, &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);
				buf_discard(buf);
				return -ENOMEM;
			}
		}
		res = tipc_bclink_send_msg(buf);
		if ((res < 0) && (dports.count != 0)) {
			buf_discard(ibuf);
		}
	} else {
		ibuf = buf;
	}

	if (res >= 0) {
		if (ibuf)
			tipc_port_recv_mcast(ibuf, &dports);
	} else {
		tipc_port_list_free(&dports);
	}
	return res;
}

/**
 * tipc_port_recv_mcast - deliver multicast message to all destination ports
 *
 * If there is no port list, perform a lookup to create one
 */

void tipc_port_recv_mcast(struct sk_buff *buf, struct port_list *dp)
{
	struct tipc_msg* msg;
	struct port_list dports = {0, NULL, };
	struct 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) {
		if (dp->count == 1) {
			msg_set_destport(msg, dp->ports[0]);
			tipc_port_recv_msg(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) {
				warn("Unable to deliver multicast message(s)\n");
				msg_dbg(msg, "LOST:");
				goto exit;
			}
			if ((index == 0) && (cnt != 0)) {
				item = item->next;
			}
			msg_set_destport(buf_msg(b),item->ports[index]);
			tipc_port_recv_msg(b);
		}
	}
exit:
	buf_discard(buf);
	tipc_port_list_free(dp);
}

/**
 * tipc_createport_raw - create a native TIPC port
 *
 * Returns local port reference
 */

u32 tipc_createport_raw(void *usr_handle,
			u32 (*dispatcher)(struct tipc_port *, struct sk_buff *),
			void (*wakeup)(struct tipc_port *),
			const u32 importance)
{
	struct port *p_ptr;
	struct tipc_msg *msg;
	u32 ref;

	p_ptr = kzalloc(sizeof(*p_ptr), GFP_ATOMIC);
	if (!p_ptr) {
		warn("Port creation failed, no memory\n");
		return 0;
	}
	ref = tipc_ref_acquire(p_ptr, &p_ptr->publ.lock);
	if (!ref) {
		warn("Port creation failed, reference table exhausted\n");
		kfree(p_ptr);
		return 0;
	}

	tipc_port_lock(ref);
	p_ptr->publ.usr_handle = usr_handle;
	p_ptr->publ.max_pkt = MAX_PKT_DEFAULT;
	p_ptr->publ.ref = ref;
	msg = &p_ptr->publ.phdr;
	msg_init(msg, DATA_LOW, TIPC_NAMED_MSG, TIPC_OK, LONG_H_SIZE, 0);
	msg_set_orignode(msg, tipc_own_addr);
	msg_set_prevnode(msg, tipc_own_addr);
	msg_set_origport(msg, ref);
	msg_set_importance(msg,importance);
	p_ptr->last_in_seqno = 41;
	p_ptr->sent = 1;
	INIT_LIST_HEAD(&p_ptr->wait_list);
	INIT_LIST_HEAD(&p_ptr->subscription.nodesub_list);
	p_ptr->congested_link = NULL;
	p_ptr->dispatcher = dispatcher;
	p_ptr->wakeup = wakeup;
	p_ptr->user_port = NULL;
	k_init_timer(&p_ptr->timer, (Handler)port_timeout, ref);
	spin_lock_bh(&tipc_port_list_lock);
	INIT_LIST_HEAD(&p_ptr->publications);
	INIT_LIST_HEAD(&p_ptr->port_list);
	list_add_tail(&p_ptr->port_list, &ports);
	spin_unlock_bh(&tipc_port_list_lock);
	tipc_port_unlock(p_ptr);
	return ref;
}

int tipc_deleteport(u32 ref)
{
	struct port *p_ptr;
	struct sk_buff *buf = NULL;

	tipc_withdraw(ref, 0, NULL);
	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;

	tipc_ref_discard(ref);
	tipc_port_unlock(p_ptr);

	k_cancel_timer(&p_ptr->timer);
	if (p_ptr->publ.connected) {
		buf = port_build_peer_abort_msg(p_ptr, TIPC_ERR_NO_PORT);
		tipc_nodesub_unsubscribe(&p_ptr->subscription);
	}
	if (p_ptr->user_port) {
		tipc_reg_remove_port(p_ptr->user_port);
		kfree(p_ptr->user_port);
	}

	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);
	kfree(p_ptr);
	dbg("Deleted port %u\n", ref);
	tipc_net_route_msg(buf);
	return TIPC_OK;
}

/**
 * tipc_get_port() - return port associated with 'ref'
 *
 * Note: Port is not locked.
 */

struct tipc_port *tipc_get_port(const u32 ref)
{
	return (struct tipc_port *)tipc_ref_deref(ref);
}

/**
 * tipc_get_handle - return user handle associated to port 'ref'
 */

void *tipc_get_handle(const u32 ref)
{
	struct port *p_ptr;
	void * handle;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return NULL;
	handle = p_ptr->publ.usr_handle;
	tipc_port_unlock(p_ptr);
	return handle;
}

static int port_unreliable(struct port *p_ptr)
{
	return msg_src_droppable(&p_ptr->publ.phdr);
}

int tipc_portunreliable(u32 ref, unsigned int *isunreliable)
{
	struct port *p_ptr;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;
	*isunreliable = port_unreliable(p_ptr);
	spin_unlock_bh(p_ptr->publ.lock);
	return TIPC_OK;
}

int tipc_set_portunreliable(u32 ref, unsigned int isunreliable)
{
	struct port *p_ptr;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;
	msg_set_src_droppable(&p_ptr->publ.phdr, (isunreliable != 0));
	tipc_port_unlock(p_ptr);
	return TIPC_OK;
}

static int port_unreturnable(struct port *p_ptr)
{
	return msg_dest_droppable(&p_ptr->publ.phdr);
}

int tipc_portunreturnable(u32 ref, unsigned int *isunrejectable)
{
	struct port *p_ptr;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;
	*isunrejectable = port_unreturnable(p_ptr);
	spin_unlock_bh(p_ptr->publ.lock);
	return TIPC_OK;
}

int tipc_set_portunreturnable(u32 ref, unsigned int isunrejectable)
{
	struct port *p_ptr;

	p_ptr = tipc_port_lock(ref);
	if (!p_ptr)
		return -EINVAL;
	msg_set_dest_droppable(&p_ptr->publ.phdr, (isunrejectable != 0));
	tipc_port_unlock(p_ptr);
	return TIPC_OK;
}

/*
 * port_build_proto_msg(): build a port level protocol
 * or a connection abortion message. Called with
 * tipc_port lock on.
 */
static struct sk_buff *port_build_proto_msg(u32 destport, u32 destnode,
					    u32 origport, u32 orignode,
					    u32 usr, u32 type, u32 err,
					    u32 seqno, u32 ack)
{
	struct sk_buff *buf;
	struct tipc_msg *msg;

	buf = buf_acquire(LONG_H_SIZE);
	if (buf) {
		msg = buf_msg(buf);
		msg_init(msg, usr, type, err, LONG_H_SIZE, destnode);
		msg_set_destport(msg, destport);
		msg_set_origport(msg, origport);
		msg_set_destnode(msg, destnode);
		msg_set_orignode(msg, orignode);
		msg_set_transp_seqno(msg, seqno);
		msg_set_msgcnt(msg, ack);
		msg_dbg(msg, "PORT>SEND>:");
	}
	return buf;
}

int tipc_set_msg_option(struct tipc_port *tp_ptr, const char *opt, const u32 sz)
{
	msg_expand(&tp_ptr->phdr, msg_destnode(&tp_ptr->phdr));
	msg_set_options(&tp_ptr->phdr, opt, sz);
	return TIPC_OK;
}

int tipc_reject_msg(struct sk_buff *buf, u32 err)
{
	struct tipc_msg *msg = buf_msg(buf);
	struct sk_buff *rbuf;
	struct tipc_msg *rmsg;
	int hdr_sz;
	u32 imp = msg_importance(msg);
	u32 data_sz = msg_data_sz(msg);

	if (data_sz > MAX_REJECT_SIZE)
		data_sz = MAX_REJECT_SIZE;
	if (msg_connected(msg) && (imp < TIPC_CRITICAL_IMPORTANCE))
		imp++;
	msg_dbg(msg, "port->rej: ");

	/* discard rejected message if it shouldn't be returned to sender */
	if (msg_errcode(msg) || msg_dest_droppable(msg)) {
		buf_discard(buf);
		return data_sz;
	}

	/* construct rejected message */
	if (msg_mcast(msg))
		hdr_sz = MCAST_H_SIZE;
	else
		hdr_sz = LONG_H_SIZE;
	rbuf = buf_acquire(data_sz + hdr_sz);
	if (rbuf == NULL) {
		buf_discard(buf);
		return data_sz;
	}
	rmsg = buf_msg(rbuf);
	msg_init(rmsg, imp, msg_type(msg), err, hdr_sz, msg_orignode(msg));
	msg_set_destport(rmsg, msg_origport(msg));
	msg_set_prevnode(rmsg, tipc_own_addr);
	msg_set_origport(rmsg, msg_destport(msg));
	if (msg_short(msg))
		msg_set_orignode(rmsg, tipc_own_addr);
	else
		msg_set_orignode(rmsg, msg_destnode(msg));
	msg_set_size(rmsg, data_sz + hdr_sz);
	msg_set_nametype(rmsg, msg_nametype(msg));
	msg_set_nameinst(rmsg, msg_nameinst(msg));
	skb_copy_to_linear_data_offset(rbuf, hdr_sz, msg_data(msg), data_sz);

	/* send self-abort message when rejecting on a connected port */
	if (msg_connected(msg)) {
		struct sk_buff *abuf = NULL;
		struct port *p_ptr = tipc_port_lock(msg_destport(msg));

		if (p_ptr) {
			if (p_ptr->publ.connected)
				abuf = port_build_self_abort_msg(p_ptr, err);
			tipc_port_unlock(p_ptr);
		}
		tipc_net_route_msg(abuf);
	}

	/* send rejected message */
	buf_discard(buf);
	tipc_net_route_msg(rbuf);
	return data_sz;
}

int tipc_port_reject_sections(struct port *p_ptr, struct tipc_msg *hdr,
			      struct iovec const *msg_sect, u32 num_sect,
			      int err)
{
	struct sk_buff *buf;
	int res;

	res = msg_build(hdr, msg_sect, num_sect, MAX_MSG_SIZE,
			!p_ptr->user_port, &buf);
	if (!buf)
		return res;

	return tipc_reject_msg(buf, err);
}

static void port_timeout(unsigned long ref)
{
	struct port *p_ptr = tipc_port_lock(ref);
	struct sk_buff *buf = NULL;

	if (!p_ptr)
		return;

	if (!p_ptr->publ.connected) {
		tipc_port_unlock(p_ptr);
		return;
	}

	/* Last probe answered ? */
	if (p_ptr->probing_state == PROBING) {
		buf = port_build_self_abort_msg(p_ptr, TIPC_ERR_NO_PORT);
	} else {
		buf = port_build_proto_msg(port_peerport(p_ptr),
					   port_peernode(p_ptr),
					   p_ptr->publ.ref,
					   tipc_own_addr,
					   CONN_MANAGER,
					   CONN_PROBE,
					   TIPC_OK,
					   port_out_seqno(p_ptr),
					   0);
		port_incr_out_seqno(p_ptr);
		p_ptr->probing_state = PROBING;
		k_start_timer(&p_ptr->timer, p_ptr->probing_interval);
	}
	tipc_port_unlock(p_ptr);
	tipc_net_route_msg(buf);
}


static void port_handle_node_down(unsigned long ref)
{
	struct port *p_ptr = tipc_port_lock(ref);
	struct sk_buff* buf = NULL;

	if (!p_ptr)
		return;
	buf = port_build_self_abort_msg(p_ptr, TIPC_ERR_NO_NODE);
	tipc_port_unlock(p_ptr);
	tipc_net_route_msg(buf);
}


static struct sk_buff *port_build_self_abort_msg(struct port *p_ptr, u32 err)
{
	u32 imp = msg_importance(&p_ptr->publ.phdr);

	if (!p_ptr->publ.connected)
		return NULL;
	if (imp < TIPC_CRITICAL_IMPORTANCE)
		imp++;
	return port_build_proto_msg(p_ptr->publ.ref,
				    tipc_own_addr,
				    port_peerport(p_ptr),
				    port_peernode(p_ptr),
				    imp,
				    TIPC_CONN_MSG,
				    err,
				    p_ptr->last_in_seqno + 1,
				    0);
}


static struct sk_buff *port_build_peer_abort_msg(struct port *p_ptr, u32 err)
{