Zabbix

/*

** Copyright (C) 2001-2024 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 web

​

import (

    "bytes"

    "crypto/tls"

    "fmt"

    "io"

    "net"

    "net/http"

    "net/http/httputil"

    "time"

​

    "golang.org/x/net/html/charset"

    "golang.org/x/text/transform"

    "golang.zabbix.com/agent2/internal/agent"

    "golang.zabbix.com/agent2/pkg/version"

    "golang.zabbix.com/sdk/log"

)

​

// Get makes a GET request to the provided web page url, using an http client, provides a response dump if dump

// parameter is set

func Get(url string, timeout time.Duration, dump bool) (string, error) {

    req, err := http.NewRequest("GET", url, nil)

    if err != nil {

        return "", fmt.Errorf("Cannot create new request: %w", err)

    }

​

    req.Header = map[string][]string{

        "User-Agent": {"Zabbix " + version.Long()},

    }

​

    client := &http.Client{

        Transport: &http.Transport{

            TLSClientConfig:   &tls.Config{InsecureSkipVerify: true},

            Proxy:             http.ProxyFromEnvironment,

            DisableKeepAlives: true,

            DialContext: (&net.Dialer{

                LocalAddr: &net.TCPAddr{IP: net.ParseIP(agent.Options.SourceIP), Port: 0},

            }).DialContext,

        },

        Timeout:       timeout,

        CheckRedirect: disableRedirect,

    }

​

    resp, err := client.Do(req)

    if err != nil {

        return "", fmt.Errorf("Cannot get content of web page: %w", err)

    }

​

    defer resp.Body.Close()

​

    if !dump {

        return "", nil

    }

​

    b, err := io.ReadAll(resp.Body)

    if err != nil {

        return "", fmt.Errorf("Cannot get content of web page: %w", err)

    }

​

    e, name, _ := charset.DetermineEncoding(b, resp.Header.Get("content-type"))

    if err != nil {

        return "", nil

    }

​

    log.Debugf("determined encoding '%s'", name)

​

    r := transform.NewReader(bytes.NewReader(b), e.NewDecoder())

​

    b, err = io.ReadAll(r)

    if err != nil {

        return "", fmt.Errorf("Cannot decode content of web page: %w", err)

    }

    h, err := httputil.DumpResponse(resp, false)

    if err != nil {

        return "", fmt.Errorf("Cannot get header of web page: %w", err)

    }