套接字错误：无法建立连接，因为目标机器主动拒绝它

Question

Note : This problem has been completely solved, as was am running client.py before server.py

Just got started with socket programming, I have created the below code and expecting to print some byte message, but it isn't doing that.

I just want to make the message available for any person on any machine. But it's refusing by the machine to do that.

Here is my code:

server.py

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
port = 12048

s.bind((socket.gethostname(), port))

s.listen()

while True:
    c, addr = s.accept()
    print("Got connection from", addr)

    c.send(bytes("Thank you", "utf-8"))

client.py

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
port = 12048

s.connect(('192.168.0.1', port))

msg = s.recv(1024)
print(msg.decode("utf-8"))

Some images to better explain my errors:

Any help would be appreciated!!!

Answer 1

It looks like in the server.py script you use s.bind((socket.gethostname(), port)) where socket.gethostname() is a hostname, but in the client.py script you use s.connect(('192.168.0.1', port)) where '192.168.0.1' is the hostname you are trying to connect.

I think there you have socket.gethostname() != '192.168.0.1' and that's the problem.

Also, you can bind to all available IP addresses on the host using this solution Python socket bind to any IP?

Let's use listen_ip = socket.gethostbyname(socket.gethostname()) for connection since socket.gethostname() may return hostname instead of IP and it will not be solved by python dns resolver in local network if it was local name, not DNS.

and use it later as s.bind((listen_ip, port)) and s.connect((listen_ip, port))

After some debugging I've got a working solution for you

There are the scripts required.

server.py

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = socket.gethostbyname(socket.gethostname())
port = 12_048

s.bind((host, port))

s.listen()
print("Server listening @ {}:{}".format(host, port))

while True:
    c, addr = s.accept()
    print("Got connection from", addr)

    c.send(bytes("Thank you", "utf-8"))

client.py

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = '192.168.1.162'  # The IP printed by the server must be set here

# or we can set it using env variable named SERVER_IP
if 'SERVER_IP' in os.environ:
    host = os.environ['SERVER_IP']

port = 12048

print("Connecting to {}:{}".format(host, port))
s.connect((host, port))

msg = s.recv(1024)
print(msg.decode("utf-8"))

Answer 2

In a chat conversation we concluded that the hardcoded IP in the question is not the correct one. This solution does have the IP he needed but it will be different in each case. Remeber that server.py needs to be launched first, and when you see the printed Server listening @ IP:12048 , write that IP in client.py and launch it. Client does need to be launched after seeing that line even if you already know the IP, as the server needs some time to be ready and the client will crash if it tries to connect to the server while it is not ready.

server.py

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = socket.gethostbyname(socket.gethostname())
port = 12048

s.bind((host, port))

s.listen()
print("Server listening @ {}:{}".format(host, port))

while True:
    c, addr = s.accept()
    print("Got connection from", addr)

    c.send(bytes("Thank you", "utf-8"))

client.py

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = '192.168.1.162'  # The IP printed by the server must be set here
port = 12048

print("Connecting to {}:{}".format(host, port))
s.connect((host, port))

msg = s.recv(1024)
print(msg.decode("utf-8"))