Zabbix

/*

** Copyright (C) 2001-2025 Zabbix SIA

**

** This program is free software: you can redistribute it and/or modify it under the terms of

** the GNU Affero General Public License as published by the Free Software Foundation, version 3.

**

** This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;

** without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

** See the GNU Affero General Public License for more details.

**

** You should have received a copy of the GNU Affero General Public License along with this program.

** If not, see <https://www.gnu.org/licenses/>.

**/

​

package external

​

import (

    "encoding/json"

    "net"

    "sync"

    "sync/atomic"

    "time"

​

    "golang.zabbix.com/sdk/errs"

    "golang.zabbix.com/sdk/log"

    "golang.zabbix.com/sdk/plugin/comms"

)

​

var (

    // ErrBrokerClosed is returned when a request is made on a closed broker.

    ErrBrokerClosed = errs.New("broker closed")

    // ErrBrokerTimeout is returned when a request sent by broker does not

    // receive a response within timeout.

    ErrBrokerTimeout = errs.New("broker timeout")

)

​

// pluginBroker handles communication with a single plugin.

type pluginBroker struct {

    timeout   time.Duration

    conn      net.Conn

    requestID atomic.Uint32

​

    // map of requestID to requests awaiting response from plugin

    requests      map[uint32]*requestWithResponse

    requestsMutex sync.Mutex

​

    // channel to handle agent to plugin requests

    // can have only *request and *requestWithResponse types

    tx chan any

​

    logr log.Logger

}

​

// describes a one directional (agent to plugin) request. err chan is closed

// when request is sent out.

type request struct {

    id  uint32

    in  any

    err chan error

}

​

// requestWithResponse describes a request that expects a response from the plugin.

// out, err chan are closed when response or error is received.