/*
 * net/tipc/port.c: TIPC port code
 *
 * Copyright (c) 1992-2007, Ericsson AB
 * Copyright (c) 2004-2008, 2010-2011, 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"

/* 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;
static struct sk_buff *msg_queue_tail;

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 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);


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

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

/**
 * 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) != port_peerport(p_ptr))
                return 0;

        orignode = msg_orignode(msg);
        peernode = port_peernode(p_ptr);
        return (orignode == peernode) ||
                (!orignode && (peernode == tipc_own_addr)) ||
                (!peernode && (orignode == tipc_own_addr));
}

/**
 * tipc_multicast - send a multicast message to local and remote destinations
 */
int tipc_multicast(u32 ref, struct tipc_name_seq const *seq,
                   u32 num_sect, struct iovec const *msg_sect,
                   unsigned int total_len)
{
        struct tipc_msg *hdr;
        struct sk_buff *buf;
        struct sk_buff *ibuf = NULL;
        struct tipc_port_list dports = {0, NULL, };
        struct tipc_port *oport = tipc_port_deref(ref);
        int ext_targets;
        int res;

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

        /* 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, num_sect, total_len, 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);
                                kfree_skb(buf);
                                return -ENOMEM;
                        }
                }
                res = tipc_bclink_send_msg(buf);
                if ((res < 0) && (dports.count != 0))
                        kfree_skb(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 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_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) {
                                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_port_recv_msg(b);
                }
        }
exit:
        kfree_skb(buf);
        tipc_port_list_free(dp);
}

/**
 * tipc_createport_raw - create a generic TIPC port
 *
 * Returns pointer to (locked) TIPC port, or NULL if unable to create it
 */
struct tipc_port *tipc_createport_raw(void *usr_handle,
                        u32 (*dispatcher)(struct tipc_port *, struct sk_buff *),
                        void (*wakeup)(struct tipc_port *),
                        const u32 importance)
{
        struct tipc_port *p_ptr;
        struct tipc_msg *msg;
        u32 ref;

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

        p_ptr->usr_handle = usr_handle;
        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);
        p_ptr->dispatcher = dispatcher;
        p_ptr->wakeup = wakeup;
        p_ptr->user_port = NULL;
        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 p_ptr;
}

int tipc_deleteport(u32 ref)
{
        struct tipc_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->connected) {
                buf = port_build_peer_abort_msg(p_ptr, TIPC_ERR_NO_PORT);
                tipc_nodesub_unsubscribe(&p_ptr->subscription);
        }
        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);
        tipc_net_route_msg(buf);
        return 0;
}

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

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

        p_ptr = tipc_port_lock(ref);
        if (!p_ptr)
                return -EINVAL;
        *isunreliable = port_unreliable(p_ptr);
        tipc_port_unlock(p_ptr);
        return 0;
}

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

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

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

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

        p_ptr = tipc_port_lock(ref);
        if (!p_ptr)
                return -EINVAL;
        *isunrejectable = port_unreturnable(p_ptr);
        tipc_port_unlock(p_ptr);
        return 0;
}

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

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

/*
 * 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,
                              port_peernode(p_ptr));
                msg_set_destport(msg, port_peerport(p_ptr));
                msg_set_origport(msg, p_ptr->ref);
                msg_set_msgcnt(msg, ack);
        }
        return buf;
}

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;
        u32 data_sz = msg_data_sz(msg);
        u32 src_node;
        u32 rmsg_sz;

        /* discard rejected message if it shouldn't be returned to sender */
        if (WARN(!msg_isdata(msg),
                 "attempt to reject message with user=%u", msg_user(msg))) {
                dump_stack();
                goto exit;
        }
        if (msg_errcode(msg) || msg_dest_droppable(msg))
                goto exit;

        /*
         * construct returned message by copying rejected message header and
         * data (or subset), then updating header fields that need adjusting
         */
        hdr_sz = msg_hdr_sz(msg);
        rmsg_sz = hdr_sz + min_t(u32, data_sz, MAX_REJECT_SIZE);

        rbuf = tipc_buf_acquire(rmsg_sz);
        if (rbuf == NULL)
                goto exit;

        rmsg = buf_msg(rbuf);
        skb_copy_to_linear_data(rbuf, msg, rmsg_sz);

        if (msg_connected(rmsg)) {
                imp = msg_importance(rmsg);
                if (imp < TIPC_CRITICAL_IMPORTANCE)
                        msg_set_importance(rmsg, ++imp);
        }
        msg_set_non_seq(rmsg, 0);
        msg_set_size(rmsg, rmsg_sz);
        msg_set_errcode(rmsg, err);
        msg_set_prevnode(rmsg, tipc_own_addr);
        msg_swap_words(rmsg, 4, 5);
        if (!msg_short(rmsg))
                msg_swap_words(rmsg, 6, 7);

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

                if (p_ptr) {
                        struct sk_buff *abuf = NULL;

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

        /* send returned message & dispose of rejected message */
        src_node = msg_prevnode(msg);
        if (in_own_node(src_node))
                tipc_port_recv_msg(rbuf);
        else
                tipc_link_send(rbuf, src_node, msg_link_selector(rmsg));
exit:
        kfree_skb(buf);
        return data_sz;
}

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

        res = tipc_msg_build(hdr, msg_sect, num_sect, total_len, 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 tipc_port *p_ptr = tipc_port_lock(ref);
        struct sk_buff *buf = NULL;

        if (!p_ptr)
                return;

        if (!p_ptr->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(p_ptr, CONN_PROBE, 0);
                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 tipc_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 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);
        }
        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);
        }
        return buf;
}

void tipc_port_recv_proto_msg(struct sk_buff *buf)
{
        struct tipc_msg *msg = buf_msg(buf);
        struct tipc_port *p_ptr;
        struct sk_buff *r_buf = NULL;
        u32 destport = msg_destport(msg);
        int wakeable;

        /* Validate connection */
        p_ptr = tipc_port_lock(destport);
        if (!p_ptr || !p_ptr->connected || !tipc_port_peer_msg(p_ptr, msg)) {
                r_buf = tipc_buf_acquire(BASIC_H_SIZE);
                if (r_buf) {
                        msg = buf_msg(r_buf);
                        tipc_msg_init(msg, TIPC_HIGH_IMPORTANCE, TIPC_CONN_MSG,
                                      BASIC_H_SIZE, msg_orignode(msg));
                        msg_set_errcode(msg, TIPC_ERR_NO_PORT);
                        msg_set_origport(msg, destport);
                        msg_set_destport(msg, msg_origport(msg));
                }
                if (p_ptr)
                        tipc_port_unlock(p_ptr);
                goto exit;
        }

        /* Process protocol message sent by peer */
        switch (msg_type(msg)) {
        case CONN_ACK:
                wakeable = tipc_port_congested(p_ptr) && p_ptr->congested &&
                        p_ptr->wakeup;
                p_ptr->acked += msg_msgcnt(msg);
                if (!tipc_port_congested(p_ptr)) {
                        p_ptr->congested = 0;
                        if (wakeable)
                                p_ptr->wakeup(p_ptr);
                }
                break;
        case CONN_PROBE:
                r_buf = port_build_proto_msg(p_ptr, CONN_PROBE_REPLY, 0);
                break;
        default:
                /* CONN_PROBE_REPLY or unrecognized - no action required */
                break;
        }
        p_ptr->probing_state = CONFIRMED;
        tipc_port_unlock(p_ptr);
exit:
        tipc_net_route_msg(r_buf);
        kfree_skb(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 = port_peerport(p_ptr);
                u32 destnode = 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);
}


/*
 *  port_dispatcher_sigh(): Signal handler for messages destinated
 *                          to the tipc_port interface.
 */
static void port_dispatcher_sigh(void *dummy)
{
        struct sk_buff *buf;

        spin_lock_bh(&queue_lock);
        buf = msg_queue_head;
        msg_queue_head = NULL;
        spin_unlock_bh(&queue_lock);

        while (buf) {
                struct tipc_port *p_ptr;
                struct user_port *up_ptr;
                struct tipc_portid orig;
                struct tipc_name_seq dseq;
                void *usr_handle;
                int connected;
                int peer_invalid;
                int published;
                u32 message_type;

                struct sk_buff *next = buf->next;
                struct tipc_msg *msg = buf_msg(buf);
                u32 dref = msg_destport(msg);

                message_type = msg_type(msg);
                if (message_type > TIPC_DIRECT_MSG)
                        goto reject;    /* Unsupported message type */

                p_ptr = tipc_port_lock(dref);
                if (!p_ptr)
                        goto reject;    /* Port deleted while msg in queue */

                orig.ref = msg_origport(msg);
                orig.node = msg_orignode(msg);
                up_ptr = p_ptr->user_port;
                usr_handle = up_ptr->usr_handle;
                connected = p_ptr->connected;
                peer_invalid = connected && !tipc_port_peer_msg(p_ptr, msg);
                published = p_ptr->published;

                if (unlikely(msg_errcode(msg)))
                        goto err;

                switch (message_type) {

                case TIPC_CONN_MSG:{
                                tipc_conn_msg_event cb = up_ptr->conn_msg_cb;
                                u32 dsz;

                                tipc_port_unlock(p_ptr);
                                if (unlikely(!cb))
                                        goto reject;
                                if (unlikely(!connected)) {
                                        if (tipc_connect2port(dref, &orig))
                                                goto reject;
                                } else if (peer_invalid)
                                        goto reject;
                                dsz = msg_data_sz(msg);
                                if (unlikely(dsz &&
                                             (++p_ptr->conn_unacked >=
                                              TIPC_FLOW_CONTROL_WIN)))
                                        tipc_acknowledge(dref,
                                                         p_ptr->conn_unacked);
                                skb_pull(buf, msg_hdr_sz(msg));
                                cb(usr_handle, dref, &buf, msg_data(msg), dsz);
                                break;
                        }
                case TIPC_DIRECT_MSG:{
                                tipc_msg_event cb = up_ptr->msg_cb;

                                tipc_port_unlock(p_ptr);
                                if (unlikely(!cb || connected))
                                        goto reject;
                                skb_pull(buf, msg_hdr_sz(msg));
                                cb(usr_handle, dref, &buf, msg_data(msg),
                                   msg_data_sz(msg), msg_importance(msg),
                                   &orig);
                                break;
                        }
                case TIPC_MCAST_MSG:
                case TIPC_NAMED_MSG:{
                                tipc_named_msg_event cb = up_ptr->named_msg_cb;

                                tipc_port_unlock(p_ptr);
                                if (unlikely(!cb || connected || !published))
                                        goto reject;
                                dseq.type =  msg_nametype(msg);
                                dseq.lower = msg_nameinst(msg);
                                dseq.upper = (message_type == TIPC_NAMED_MSG)
                                        ? dseq.lower : msg_nameupper(msg);
                                skb_pull(buf, msg_hdr_sz(msg));
                                cb(usr_handle, dref, &buf, msg_data(msg),
                                   msg_data_sz(msg), msg_importance(msg),
                                   &orig, &dseq);
                                break;
                        }
                }
                if (buf)
                        kfree_skb(buf);
                buf = next;
                continue;
err:
                switch (message_type) {

                case TIPC_CONN_MSG:{
                                tipc_conn_shutdown_event cb =
                                        up_ptr->conn_err_cb;

                                tipc_port_unlock(p_ptr);
                                if (!cb || !connected || peer_invalid)
                                        break;
                                tipc_disconnect(dref);
                                skb_pull(buf, msg_hdr_sz(msg));
                                cb(usr_handle, dref, &buf, msg_data(msg),
                                   msg_data_sz(msg), msg_errcode(msg));
                                break;
                        }
                case TIPC_DIRECT_MSG:{
                                tipc_msg_err_event cb = up_ptr->err_cb;

                                tipc_port_unlock(p_ptr);
                                if (!cb || connected)
                                        break;
                                skb_pull(buf, msg_hdr_sz(msg));
                                cb(usr_handle, dref, &buf, msg_data(msg),
                                   msg_data_sz(msg), msg_errcode(msg), &orig);
                                break;
                        }
                case TIPC_MCAST_MSG:
                case TIPC_NAMED_MSG:{
                                tipc_named_msg_err_event cb =
                                        up_ptr->named_err_cb;

                                tipc_port_unlock(p_ptr);
                                if (!cb || connected)
                                        break;
                                dseq.type =  msg_nametype(msg);
                                dseq.lower = msg_nameinst(msg);
                                dseq.upper = (message_type == TIPC_NAMED_MSG)
                                        ? dseq.lower : msg_nameupper(msg);
                                skb_pull(buf, msg_hdr_sz(msg));
                                cb(usr_handle, dref, &buf, msg_data(msg),
                                   msg_data_sz(msg), msg_errcode(msg), &dseq);
                                break;
                        }
                }
                if (buf)
                        kfree_skb(buf);
                buf = next;
                continue;
reject:
                tipc_reject_msg(buf, TIPC_ERR_NO_PORT);
                buf = next;
        }
}

/*
 *  port_dispatcher(): Dispatcher for messages destinated
 *  to the tipc_port interface. Called with port locked.
 */
static u32 port_dispatcher(struct tipc_port *dummy, struct sk_buff *buf)
{
        buf->next = NULL;
        spin_lock_bh(&queue_lock);
        if (msg_queue_head) {
                msg_queue_tail->next = buf;
                msg_queue_tail = buf;
        } else {
                msg_queue_tail = msg_queue_head = buf;
                tipc_k_signal((Handler)port_dispatcher_sigh, 0);
        }
        spin_unlock_bh(&queue_lock);
        return 0;
}

/*
 * Wake up port after congestion: Called with port locked
 */
static void port_wakeup_sh(unsigned long ref)
{
        struct tipc_port *p_ptr;
        struct user_port *up_ptr;
        tipc_continue_event cb = NULL;
        void *uh = NULL;

        p_ptr = tipc_port_lock(ref);
        if (p_ptr) {
                up_ptr = p_ptr->user_port;
                if (up_ptr) {
                        cb = up_ptr->continue_event_cb;
                        uh = up_ptr->usr_handle;
                }
                tipc_port_unlock(p_ptr);
        }
        if (cb)
                cb(uh, ref);
}


static void port_wakeup(struct tipc_port *p_ptr)
{
        tipc_k_signal((Handler)port_wakeup_sh, p_ptr->ref);
}

void tipc_acknowledge(u32 ref, u32 ack)
{
        struct tipc_port *p_ptr;
        struct sk_buff *buf = NULL;

        p_ptr = tipc_port_lock(ref);
        if (!p_ptr)
                return;
        if (p_ptr->connected) {
                p_ptr->conn_unacked -= ack;
                buf = port_build_proto_msg(p_ptr, CONN_ACK, ack);
        }
        tipc_port_unlock(p_ptr);
        tipc_net_route_msg(buf);
}

/*
 * tipc_createport(): user level call.
 */
int tipc_createport(void *usr_handle,
                    unsigned int importance,
                    tipc_msg_err_event error_cb,
                    tipc_named_msg_err_event named_error_cb,
                    tipc_conn_shutdown_event conn_error_cb,
                    tipc_msg_event msg_cb,
                    tipc_named_msg_event named_msg_cb,
                    tipc_conn_msg_event conn_msg_cb,
                    tipc_continue_event continue_event_cb, /* May be zero */
                    u32 *portref)
{
        struct user_port *up_ptr;
        struct tipc_port *p_ptr;

        up_ptr = kmalloc(sizeof(*up_ptr), GFP_ATOMIC);
        if (!up_ptr) {
                pr_warn("Port creation failed, no memory\n");
                return -ENOMEM;
        }
        p_ptr = tipc_createport_raw(NULL, port_dispatcher, port_wakeup,
                                    importance);
        if (!p_ptr) {
                kfree(up_ptr);
                return -ENOMEM;
        }

        p_ptr->user_port = up_ptr;
        up_ptr->usr_handle = usr_handle;
        up_ptr->ref = p_ptr->ref;
        up_ptr->err_cb = error_cb;
        up_ptr->named_err_cb = named_error_cb;
        up_ptr->conn_err_cb = conn_error_cb;
        up_ptr->msg_cb = msg_cb;
        up_ptr->named_msg_cb = named_msg_cb;
        up_ptr->conn_msg_cb = conn_msg_cb;
        up_ptr->continue_event_cb = continue_event_cb;
        *portref = p_ptr->ref;
        tipc_port_unlock(p_ptr);
        return 0;
}

int tipc_portimportance(u32 ref, unsigned int *importance)
{
        struct tipc_port *p_ptr;

        p_ptr = tipc_port_lock(ref);
        if (!p_ptr)
                return -EINVAL;
        *importance = (unsigned int)msg_importance(&p_ptr->phdr);
        tipc_port_unlock(p_ptr);
        return 0;
}

int tipc_set_portimportance(u32 ref, unsigned int imp)
{
        struct tipc_port *p_ptr;

        if (imp > TIPC_CRITICAL_IMPORTANCE)
                return -EINVAL;

        p_ptr = tipc_port_lock(ref);
        if (!p_ptr)
                return -EINVAL;
        msg_set_importance(&p_ptr->phdr, (u32)imp);
        tipc_port_unlock(p_ptr);
        return 0;
}


int tipc_publish(u32 ref, unsigned int scope, struct tipc_name_seq const *seq)
{
        struct tipc_port *p_ptr;
        struct publication *publ;
        u32 key;
        int res = -EINVAL;

        p_ptr = tipc_port_lock(ref);
        if (!p_ptr)
                return -EINVAL;

        if (p_ptr->connected)
                goto exit;
        key = ref + p_ptr->pub_count + 1;
        if (key == ref) {
                res = -EADDRINUSE;
                goto exit;
        }
        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;
                res = 0;
        }
exit:
        tipc_port_unlock(p_ptr);
        return res;
}

int tipc_withdraw(u32 ref, unsigned int scope, struct tipc_name_seq const *seq)
{

        struct tipc_port *p_ptr;
        struct publication *publ;
        struct publication *tpubl;
        int res = -EINVAL;

        p_ptr = tipc_port_lock(ref);
        if (!p_ptr)
                return -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;
        tipc_port_unlock(p_ptr);
        return res;
}

int tipc_connect2port(u32 ref, struct tipc_portid const *peer)
{
        struct tipc_port *p_ptr;
        struct tipc_msg *msg;
        int res = -EINVAL;

        p_ptr = tipc_port_lock(ref);
        if (!p_ptr)
                return -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 = CONFIRMED;
        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:
        tipc_port_unlock(p_ptr);
        p_ptr->max_pkt = tipc_link_get_max_pkt(peer->node, ref);
        return res;
}

/**
 * tipc_disconnect_port - disconnect port from peer
 *
 * Port must be locked.
 */
int tipc_disconnect_port(struct tipc_port *tp_ptr)
{
        int res;

        if (tp_ptr->connected) {
                tp_ptr->connected = 0;
                /* let timer expire on it's own to avoid deadlock! */
                tipc_nodesub_unsubscribe(&tp_ptr->subscription);
                res = 0;
        } else {
                res = -ENOTCONN;
        }
        return res;
}

/*
 * tipc_disconnect(): Disconnect port form peer.
 *                    This is a node local operation.
 */
int tipc_disconnect(u32 ref)
{
        struct tipc_port *p_ptr;
        int res;

        p_ptr = tipc_port_lock(ref);
        if (!p_ptr)
                return -EINVAL;
        res = tipc_disconnect_port(p_ptr);
        tipc_port_unlock(p_ptr);
        return res;
}

/*
 * tipc_shutdown(): Send a SHUTDOWN msg to peer and disconnect
 */
int tipc_shutdown(u32 ref)
{
        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);
        tipc_net_route_msg(buf);
        return tipc_disconnect(ref);
}

/**
 * tipc_port_recv_msg - receive message from lower layer and deliver to port user
 */
int tipc_port_recv_msg(struct sk_buff *buf)
{
        struct tipc_port *p_ptr;
        struct tipc_msg *msg = buf_msg(buf);
        u32 destport = msg_destport(msg);
        u32 dsz = msg_data_sz(msg);
        u32 err;

        /* forward unresolved named message */
        if (unlikely(!destport)) {
                tipc_net_route_msg(buf);
                return dsz;
        }

        /* validate destination & pass to port, otherwise reject message */
        p_ptr = tipc_port_lock(destport);
        if (likely(p_ptr)) {
                err = p_ptr->dispatcher(p_ptr, buf);
                tipc_port_unlock(p_ptr);
                if (likely(!err))
                        return dsz;
        } else {
                err = TIPC_ERR_NO_PORT;
        }

        return tipc_reject_msg(buf, err);
}

/*
 *  tipc_port_recv_sections(): Concatenate and deliver sectioned
 *                        message for this node.
 */
static int tipc_port_recv_sections(struct tipc_port *sender, unsigned int num_sect,
                                   struct iovec const *msg_sect,
                                   unsigned int total_len)
{
        struct sk_buff *buf;
        int res;

        res = tipc_msg_build(&sender->phdr, msg_sect, num_sect, total_len,
                        MAX_MSG_SIZE, !sender->user_port, &buf);
        if (likely(buf))
                tipc_port_recv_msg(buf);
        return res;
}

/**
 * tipc_send - send message sections on connection
 */
int tipc_send(u32 ref, unsigned int num_sect, struct iovec const *msg_sect,
              unsigned int total_len)
{
        struct tipc_port *p_ptr;
        u32 destnode;
        int res;

        p_ptr = tipc_port_deref(ref);
        if (!p_ptr || !p_ptr->connected)
                return -EINVAL;

        p_ptr->congested = 1;
        if (!tipc_port_congested(p_ptr)) {
                destnode = port_peernode(p_ptr);
                if (likely(!in_own_node(destnode)))
                        res = tipc_link_send_sections_fast(p_ptr, msg_sect, num_sect,
                                                           total_len, destnode);
                else
                        res = tipc_port_recv_sections(p_ptr, num_sect, msg_sect,
                                                      total_len);

                if (likely(res != -ELINKCONG)) {
                        p_ptr->congested = 0;
                        if (res > 0)
                                p_ptr->sent++;
                        return res;
                }
        }
        if (port_unreliable(p_ptr)) {
                p_ptr->congested = 0;
                return total_len;
        }
        return -ELINKCONG;
}

/**
 * tipc_send2name - send message sections to port name
 */
int tipc_send2name(u32 ref, struct tipc_name const *name, unsigned int domain,
                   unsigned int num_sect, struct iovec const *msg_sect,
                   unsigned int total_len)
{
        struct tipc_port *p_ptr;
        struct tipc_msg *msg;
        u32 destnode = domain;
        u32 destport;
        int res;

        p_ptr = tipc_port_deref(ref);
        if (!p_ptr || p_ptr->connected)
                return -EINVAL;

        msg = &p_ptr->phdr;
        msg_set_type(msg, TIPC_NAMED_MSG);
        msg_set_hdr_sz(msg, NAMED_H_SIZE);
        msg_set_nametype(msg, name->type);
        msg_set_nameinst(msg, name->instance);
        msg_set_lookup_scope(msg, tipc_addr_scope(domain));
        destport = tipc_nametbl_translate(name->type, name->instance, &destnode);
        msg_set_destnode(msg, destnode);
        msg_set_destport(msg, destport);

        if (likely(destport || destnode)) {
                if (likely(in_own_node(destnode)))
                        res = tipc_port_recv_sections(p_ptr, num_sect,
                                                      msg_sect, total_len);
                else if (tipc_own_addr)
                        res = tipc_link_send_sections_fast(p_ptr, msg_sect,
                                                           num_sect, total_len,
                                                           destnode);
                else
                        res = tipc_port_reject_sections(p_ptr, msg, msg_sect,
                                                        num_sect, total_len,
                                                        TIPC_ERR_NO_NODE);
                if (likely(res != -ELINKCONG)) {
                        if (res > 0)
                                p_ptr->sent++;
                        return res;
                }
                if (port_unreliable(p_ptr)) {
                        return total_len;
                }
                return -ELINKCONG;
        }
        return tipc_port_reject_sections(p_ptr, msg, msg_sect, num_sect,
                                         total_len, TIPC_ERR_NO_NAME);
}

/**
 * tipc_send2port - send message sections to port identity
 */
int tipc_send2port(u32 ref, struct tipc_portid const *dest,
                   unsigned int num_sect, struct iovec const *msg_sect,
                   unsigned int total_len)
{
        struct tipc_port *p_ptr;
        struct tipc_msg *msg;
        int res;

        p_ptr = tipc_port_deref(ref);
        if (!p_ptr || p_ptr->connected)
                return -EINVAL;

        msg = &p_ptr->phdr;
        msg_set_type(msg, TIPC_DIRECT_MSG);
        msg_set_lookup_scope(msg, 0);
        msg_set_destnode(msg, dest->node);
        msg_set_destport(msg, dest->ref);
        msg_set_hdr_sz(msg, BASIC_H_SIZE);

        if (in_own_node(dest->node))
                res =  tipc_port_recv_sections(p_ptr, num_sect, msg_sect,
                                               total_len);
        else if (tipc_own_addr)
                res = tipc_link_send_sections_fast(p_ptr, msg_sect, num_sect,
                                                   total_len, dest->node);
        else
                res = tipc_port_reject_sections(p_ptr, msg, msg_sect, num_sect,
                                                total_len, TIPC_ERR_NO_NODE);
        if (likely(res != -ELINKCONG)) {
                if (res > 0)
                        p_ptr->sent++;
                return res;
        }
        if (port_unreliable(p_ptr)) {
                return total_len;
        }
        return -ELINKCONG;
}

/**
 * tipc_send_buf2port - send message buffer to port identity
 */
int tipc_send_buf2port(u32 ref, struct tipc_portid const *dest,
               struct sk_buff *buf, unsigned int dsz)
{
        struct tipc_port *p_ptr;
        struct tipc_msg *msg;
        int res;

        p_ptr = (struct tipc_port *)tipc_ref_deref(ref);
        if (!p_ptr || p_ptr->connected)
                return -EINVAL;

        msg = &p_ptr->phdr;
        msg_set_type(msg, TIPC_DIRECT_MSG);
        msg_set_destnode(msg, dest->node);
        msg_set_destport(msg, dest->ref);
        msg_set_hdr_sz(msg, BASIC_H_SIZE);
        msg_set_size(msg, BASIC_H_SIZE + dsz);
        if (skb_cow(buf, BASIC_H_SIZE))
                return -ENOMEM;

        skb_push(buf, BASIC_H_SIZE);
        skb_copy_to_linear_data(buf, msg, BASIC_H_SIZE);

        if (in_own_node(dest->node))
                res = tipc_port_recv_msg(buf);
        else
                res = tipc_send_buf_fast(buf, dest->node);
        if (likely(res != -ELINKCONG)) {
                if (res > 0)
                        p_ptr->sent++;
                return res;
        }
        if (port_unreliable(p_ptr))
                return dsz;
        return -ELINKCONG;
}