使用golang访问linux telnet服务器

参考https://www.cnblogs.com/dpf-10/p/10429358.html

package main

import (
    "errors"
    "log"
    "net"
    "strings"
    "time"
)

type TelnetClient struct {
    IP               string
    Port             string
    IsAuthentication bool
    UserName         string
    Password         string
}

func cmd_do(conn net.Conn, cmd string) string {

    var buf [40960]byte
    line_prompt := "root> "
    cmd_w := cmd + "\r\n"
    n_w, err_w := conn.Write([]byte(cmd_w))
    if nil != err_w {
        log.Println("pkg: model, func: Telnet, method: conn.Write, errInfo:", err_w)
        return ""
    }

    conn.SetReadDeadline(time.Now().Add(time.Second * 5))

    max_try := 100
    index := 0
    n_r := 0
    n_r_total := 0
    recv_str := ""
    var err_r error
    for ; index < max_try; index++ {
        time.Sleep(time.Millisecond * 10)
        n_r, err_r = conn.Read(buf[n_r_total:])
        if nil != err_r {
            log.Print("pkg: model, func: telnetProtocolHandshake, method: conn.Read, errInfo:", err_r)
            return ""
        }
        n_r_total += n_r
        log.Printf("%d:%d", n_w, n_r_total)
        if (n_r_total <= n_w) {
            continue
        }

        recv_str = string(buf[n_w:n_r_total])
        if (0 > strings.Index(recv_str, line_prompt)) {
            continue
        }
        break
    }

    if max_try == index {
        return ""
    }

    index_begin := strings.Index(recv_str, cmd_w)
    index_end := strings.Index(recv_str, line_prompt)

    if (0 < index_begin) {
        index_begin += len(cmd_w)
    } else {
        index_begin = 0
    }

    if (0 > index_end) {
        index_end = len(recv_str)
    }

    return recv_str[index_begin:index_end]
}

func telnet_Creat(host string, port string,usr string,pass string)  (conn net.Conn, err error) {
    telnetClientObj := new(TelnetClient)
    telnetClientObj.IP = host
    telnetClientObj.Port = port
    telnetClientObj.IsAuthentication = true
    telnetClientObj.UserName = usr
    telnetClientObj.Password = pass
    conn,err =telnetClientObj.Telnet(20)

    return conn,err
}
func (this *TelnetClient) Telnet(timeout int) (conn net.Conn, err error) {  
    raddr := this.IP + ":" + this.Port   
    
    conn, err = net.DialTimeout("tcp", raddr, time.Duration(timeout)*time.Second)  
    if nil != err {     
        log.Print("pkg: model, func: Telnet, method: net.DialTimeout, errInfo:", err)     
        return 
    }  
    
    conn.SetReadDeadline(time.Now().Add(time.Second * 5))

    if false == this.telnetProtocolHandshake(conn) {      
        log.Print("pkg: model, func: Telnet, method: this.telnetProtocolHandshake, errInfo: telnet protocol handshake failed!!!")      
        return conn, errors.New("Access denied")
    }   

    return conn, err
}

func (this *TelnetClient) telnetProtocolHandshake(conn net.Conn) bool {
    var buf [4096]byte
    log.Print("telnetProtocolHandshake")
    n, err := conn.Read(buf[0:])
    if nil != err {
        log.Print("pkg: model, func: telnetProtocolHandshake, method: conn.Read, errInfo:", err)
        return false
    }
    // log.Print("1====",string(buf[0:n]))
    // log.Printf("%x",(buf[0:n]))
    buf[0] = 0xff
    buf[1] = 0xfc
    buf[2] = 0x25
    buf[3] = 0xff
    buf[4] = 0xfe
    buf[5] = 0x01
    n, err = conn.Write(buf[0:6])
    if nil != err {
        log.Print("pkg: model, func: telnetProtocolHandshake, method: conn.Write, errInfo:", err)
        return false
    }

    n, err = conn.Read(buf[0:])
    if nil != err {
        log.Print("pkg: model, func: telnetProtocolHandshake, method: conn.Read, errInfo:", err)
        return false
    }
    // log.Print("2====", string(buf[0:n]))
    // buf[0] = 0xff
    // buf[1] = 0xfe
    // buf[2] = 0x03
    // buf[3] = 0xff
    // buf[4] = 0xfc
    // buf[5] = 0x27
    // n, err = conn.Write(buf[0:6])
    // if nil != err {
    //     log.Print("pkg: model, func: telnetProtocolHandshake, method: conn.Write, errInfo:", err)
    //     return false
    // }
    // log.Print("2.1====",string(buf[0:6]))

    // n, err = conn.Read(buf[0:])
    // if nil != err {
    //     log.Print("pkg: model, func: telnetProtocolHandshake, method: conn.Read, errInfo:", err)
    //     return false
    // }
    // log.Print("3====",string(buf[0:n]))
    n, err = conn.Write([]byte(this.UserName + "\r\n"))
    if nil != err {
        log.Print("pkg: model, func: telnetProtocolHandshake, method: conn.Write, errInfo:", err)
        return false
    }
    time.Sleep(time.Millisecond * 50)

    n, err = conn.Read(buf[0:])
    if nil != err {
        log.Print("pkg: model, func: telnetProtocolHandshake, method: conn.Read, errInfo:", err)
        return false
    }
    // log.Print("4====",string(buf[0:n]))
    n, err = conn.Write([]byte(this.Password+ "\r\n"))
    if nil != err {
        log.Print("pkg: model, func: telnetProtocolHandshake, method: conn.Write, errInfo:", err)
        return false
    }
    time.Sleep(time.Millisecond * 50)
    n, err = conn.Read(buf[0:])
    if nil != err {
        log.Print("pkg: model, func: telnetProtocolHandshake, method: conn.Read, errInfo:", err)
        return false
    }

    // log.Printf("5====%s\n",string(buf[0:n]))
    // log.Printf("5====%s|5isover, n=%d\n",string(buf[0:n]), n)

    if strings.Contains(string(buf[0:n]), "Access denied") {
        return false
    }

    // buf[0] = 0xff
    // buf[1] = 0xfc
    // buf[2] = 0x18
    // n, err = conn.Write(buf[0:3])
    // if nil != err {
    //     log.Print("pkg: model, func: telnetProtocolHandshake, method: conn.Write, errInfo:", err)
    //     return false
    // }
    // log.Printf("5.1====%s|5isover",string(buf[0:n]))

    // n, err = conn.Read(buf[0:])
    // if nil != err {
    //     log.Print("pkg: model, func: telnetProtocolHandshake, method: conn.Read, errInfo:", err)
    //     return false
    // }
    // log.Print("6====",string(buf[0:n]))

    return true
}

func Dev_cmd_do(dev_IP string, cmd_arr []string) map[string]string {
    host := dev_IP
    port := "8000"
    usr := "root"
    pass := "root@1234"

    m_out := make(map[string]string, 0)

    conn, err:= telnet_Creat(host, port, usr, pass)
    if nil != err {
        log.Print(err)
        return m_out
    }
    defer conn.Close()  
//后续对conn进行操作即可

    for _, cmd_each := range cmd_arr {
        cmd_out := cmd_do(conn, cmd_each)
        log.Printf("req=%s, resp=%s", cmd_each, string(cmd_out))
        m_out[cmd_each] = cmd_out
    }
    // log.Printf("%s====>>>>%s<<<<,L=%d", cmd, string(cmd_out), len(cmd_out))

    return m_out
}


func main() {
    // host := "172.20.10.198"
    host := "172.20.40.64"

    // cmd := []string{"rsp_get_version", "rsp_get_link_status -p0"}
    cmd_arr := []string{"rsp_get_version", 
                        "rsp_get_band_freq"      ,
                        "rsp_get_frm_struct"     ,
                        "rsp_get_link_status -p0",
                        "rsp_get_link_status -p1",
                        "rsp_get_link_status -p2",
                        "rsp_get_link_status -p3",
                        "rsp_get_link_status -p4",
                        "rsp_get_link_status -p5",
                        "rsp_get_link_status -p6",
                        "rsp_get_link_status -p7",
                        "rsp_get_link_status -p8",
                        "rsp_get_link_status -p9",
                        "rsp_get_version"        }

    Dev_cmd_do(host, cmd_arr)
}