Tarmoq nosozliklarini aniqlash

import socket
import threading

PORT = 9952
SAHIFA = b"<h1>ishlayapti</h1>"

tinglovchi = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tinglovchi.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
tinglovchi.bind(("127.0.0.1", PORT))
tinglovchi.listen(2)


def server(nechta):
    for _ in range(nechta):
        u, _ = tinglovchi.accept()
        u.recv(1024)
        u.sendall(b"HTTP/1.1 200 OK\r\nContent-Length: "
                  + str(len(SAHIFA)).encode() + b"\r\n\r\n" + SAHIFA)
        u.close()


threading.Thread(target=server, args=(1,), daemon=True).start()


def tashxis(xost, port, yol="/"):
    """Har qatlamni pastdan yuqoriga tekshiradi."""
    natija = []

    # 1-qadam: nom manzilga aylanadimi?
    try:
        manzil = socket.gethostbyname(xost)
        natija.append(("DNS", "ok", manzil))
    except socket.gaierror:
        natija.append(("DNS", "XATO", "nom hal qilinmadi"))
        return natija

    # 2-qadam: TCP ulanish o'rnatiladimi?
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.settimeout(3)
    try:
        s.connect((manzil, port))
        natija.append(("TCP", "ok", f"{manzil}:{port}"))
    except ConnectionRefusedError:
        natija.append(("TCP", "XATO", "rad etildi - xizmat ishlamayapti"))
        return natija
    except socket.timeout:
        natija.append(("TCP", "XATO", "javob yo'q - firewall?"))
        return natija

    # 3-qadam: HTTP javob beradimi?
    try:
        s.sendall(f"GET {yol} HTTP/1.1\r\nHost: {xost}\r\n"
                  f"Connection: close\r\n\r\n".encode())
        javob = s.recv(4096)
        holat = javob.split(b"\r\n")[0].decode()
        natija.append(("HTTP", "ok", holat))
    except OSError as x:
        natija.append(("HTTP", "XATO", str(x)))
    finally:
        s.close()

    return natija


for nom, port in [("localhost", PORT), ("localhost", 9953)]:
    print(f"--- tashxis: {nom}:{port}")
    for qatlam, holat, izoh in tashxis(nom, port):
        belgi = "+" if holat == "ok" else "!"
        print(f"  {belgi} {qatlam:<5} {holat:<5} {izoh}")
    print()

tinglovchi.close()

import socket
import threading

# Ikkita port: biri ochiq, biri yopiq
OCHIQ = 9950
YOPIQ = 9951

tinglovchi = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tinglovchi.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
tinglovchi.bind(("127.0.0.1", OCHIQ))
tinglovchi.listen(2)


def server():
    ulanish, _ = tinglovchi.accept()
    ulanish.close()


threading.Thread(target=server, daemon=True).start()


def tekshir(manzil, port, kutish=2.0):
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.settimeout(kutish)
    try:
        s.connect((manzil, port))
        return "OCHIQ - kimdir tinglayapti"
    except ConnectionRefusedError:
        return "YOPIQ - port bo'sh, lekin xost javob berdi"
    except socket.timeout:
        return "JAVOB YO'Q - xost yoki devor jim turibdi"
    except socket.gaierror:
        return "NOM TOPILMADI - DNS muammosi"
    except OSError as x:
        return f"XATO - {x.strerror}"
    finally:
        s.close()


SINOVLAR = [
    ("127.0.0.1", OCHIQ),
    ("127.0.0.1", YOPIQ),
    ("192.0.2.1", 80),          # hujjatlar uchun ajratilgan - javob bermaydi
    ("mavjud-emas.invalid", 80),
]

for manzil, port in SINOVLAR:
    print(f"{manzil}:{port}")
    print("   ", tekshir(manzil, port))

tinglovchi.close()