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@rsperl

rsperl/check_port.go

Last active July 25, 2022 12:42
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Revisions

  1. rsperl revised this gist Jul 25, 2022. No changes.
  2. rsperl revised this gist Jul 8, 2022. 1 changed file with 48 additions and 21 deletions.
    69 changes: 48 additions & 21 deletions check_port.go
    View file
    Original file line number Diff line number Diff line change
    @@ -1,15 +1,21 @@
    package main

    import (
    "time"
    "net"
    "fmt"
    "log"
    "net"
    "os"
    "regexp"
    "strconv"
    "time"
    )

    // CheckPort checks a given port on a given host and returns a boolean to indicate port status
    // and an error if one occured. The error could be a timeout (box is offline) or connection refused
    // (port closed), or if the ulimit is not properly set, it could be "too many open files"
    func CheckPort(hostname string, p int) (bool, error) {
    func CheckPort(hostname string, p int64) (bool, error) {
    i := fmt.Sprintf("%s:%d", hostname, p)
    timeout := time.Duration(PortCheckTimeout) * time.Second
    timeout := time.Duration(3) * time.Second
    c, err := net.DialTimeout("tcp", i, timeout)
    if err != nil {
    return false, err
    @@ -18,25 +24,46 @@ func CheckPort(hostname string, p int) (bool, error) {
    return true, nil
    }

    // collect args and ensure ports are integers
    func getArgs(args []string) (hostname string, ports []int64) {
    hostname = os.Args[1]
    for _, s := range os.Args[2:] {
    p, err := strconv.ParseInt(s, 10, 64)
    if err != nil {
    panic(fmt.Errorf("could not parse port as int: %s\n", s))
    }
    ports = append(ports, p)
    }
    return hostname, ports
    }

    func main() {
    isOpen, err := CheckPort(s.IP, p)
    if len(os.Args) < 2 {
    fmt.Printf("Usage: %s <hostname> <port1> <port2> ...\n", os.Args[0])
    os.Exit(1)
    }
    hostname, ports := getArgs(os.Args)

    log.Printf("Hostname: %s\n", hostname)
    log.Printf("Ports: %v\n", ports)

    for _, port := range ports {
    isOpen, err := CheckPort(hostname, port)
    hostport := fmt.Sprintf("[%s:%d]:", hostname, port)
    if err != nil {
    if err, ok := err.(net.Error); ok && err.Timeout() {
    log.Printf("port timeout: %s:%v (%s)", s.IP, p, s.Hostname)
    return
    log.Printf("%s port timeout", hostport)
    } else if match, _ := regexp.MatchString(".*connection refused.*", err.Error()); match {
    log.Printf("%s port closed", hostport)
    } else if match, _ := regexp.MatchString(".*too many open files*", err.Error()); match {
    log.Fatalf("%s %v", hostport, err)
    } else {
    log.Fatalf("%s unknown error: %v", hostport, err)
    }
    if match, _ := regexp.MatchString(".*connection refused.*", err.Error()); match {
    log.Printf("port closed: %s:%v (%s)", s.IP, p, s.Hostname)
    return
    }
    if match, _ := regexp.MatchString(".*too many open files*", err.Error()); match {
    log.Fatal(err)
    }
    }

    if isOpen {
    log.Printf("port open: %s:%v (%s)", s.IP, p, s.Hostname)
    s.Ports = append(s.Ports, p)
    } else if isOpen {
    log.Printf("%s port open", hostport)
    } else {
    log.Printf("port closed, but no error: %s:%v (%s)", s.IP, p, s.Hostname)
    }
    log.Printf("%sport closed, but no error", hostport)
    }
    }
    }
  3. rsperl created this gist Jul 8, 2022.
    42 changes: 42 additions & 0 deletions check_port.go
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,42 @@

    import (
    "time"
    "net"
    )

    // CheckPort checks a given port on a given host and returns a boolean to indicate port status
    // and an error if one occured. The error could be a timeout (box is offline) or connection refused
    // (port closed), or if the ulimit is not properly set, it could be "too many open files"
    func CheckPort(hostname string, p int) (bool, error) {
    i := fmt.Sprintf("%s:%d", hostname, p)
    timeout := time.Duration(PortCheckTimeout) * time.Second
    c, err := net.DialTimeout("tcp", i, timeout)
    if err != nil {
    return false, err
    }
    defer c.Close()
    return true, nil
    }

    func main() {
    isOpen, err := CheckPort(s.IP, p)
    if err != nil {
    if err, ok := err.(net.Error); ok && err.Timeout() {
    log.Printf("port timeout: %s:%v (%s)", s.IP, p, s.Hostname)
    return
    }
    if match, _ := regexp.MatchString(".*connection refused.*", err.Error()); match {
    log.Printf("port closed: %s:%v (%s)", s.IP, p, s.Hostname)
    return
    }
    if match, _ := regexp.MatchString(".*too many open files*", err.Error()); match {
    log.Fatal(err)
    }
    }

    if isOpen {
    log.Printf("port open: %s:%v (%s)", s.IP, p, s.Hostname)
    s.Ports = append(s.Ports, p)
    } else {
    log.Printf("port closed, but no error: %s:%v (%s)", s.IP, p, s.Hostname)
    }