Repository: bitcoin/bitcoin
File: test/functional/interface_http.py (Python)

Code before:
#!/usr/bin/env python3
# Copyright (c) 2014-2021 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.
"""Test the RPC HTTP basics."""

from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import assert_equal, str_to_b64str

import http.client
import urllib.parse

class HTTPBasicsTest (BitcoinTestFramework):
    def set_test_params(self):
        self.num_nodes = 3
        self.supports_cli = False

    def setup_network(self):
        self.setup_nodes()

    def run_test(self):

        #################################################
        # lowlevel check for http persistent connection #
        #################################################
        url = urllib.parse.urlparse(self.nodes[0].url)
        authpair = f'{url.username}:{url.password}'
        headers = {"Authorization": f"Basic {str_to_b64str(authpair)}"}

        conn = http.client.HTTPConnection(url.hostname, url.port)
        conn.connect()
        conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
        out1 = conn.getresponse().read()
        assert b'"error":null' in out1
        assert conn.sock is not None  #according to http/1.1 connection must still be open!

        #send 2nd request without closing connection
        conn.request('POST', '/', '{"method": "getchaintips"}', headers)
        out1 = conn.getresponse().read()
        assert b'"error":null' in out1  #must also response with a correct json-rpc message
        assert conn.sock is not None  #according to http/1.1 connection must still be open!
        conn.close()

        #same should be if we add keep-alive because this should be the std. behaviour
        headers = {"Authorization": f"Basic {str_to_b64str(authpair)}", "Connection": "keep-alive"}

        conn = http.client.HTTPConnection(url.hostname, url.port)
        conn.connect()
        conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
        out1 = conn.getresponse().read()
        assert b'"error":null' in out1
        assert conn.sock is not None  #according to http/1.1 connection must still be open!

        #send 2nd request without closing connection
        conn.request('POST', '/', '{"method": "getchaintips"}', headers)
        out1 = conn.getresponse().read()
        assert b'"error":null' in out1  #must also response with a correct json-rpc message
        assert conn.sock is not None  #according to http/1.1 connection must still be open!
        conn.close()

        #now do the same with "Connection: close"
        headers = {"Authorization": f"Basic {str_to_b64str(authpair)}", "Connection":"close"}

        conn = http.client.HTTPConnection(url.hostname, url.port)
        conn.connect()
        conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
        out1 = conn.getresponse().read()
        assert b'"error":null' in out1
        assert conn.sock is None  #now the connection must be closed after the response

        #node1 (2nd node) is running with disabled keep-alive option
        urlNode1 = urllib.parse.urlparse(self.nodes[1].url)
        authpair = f'{urlNode1.username}:{urlNode1.password}'
        headers = {"Authorization": f"Basic {str_to_b64str(authpair)}"}

        conn = http.client.HTTPConnection(urlNode1.hostname, urlNode1.port)
        conn.connect()
        conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
        out1 = conn.getresponse().read()
        assert b'"error":null' in out1

        #node2 (third node) is running with standard keep-alive parameters which means keep-alive is on
        urlNode2 = urllib.parse.urlparse(self.nodes[2].url)
        authpair = f'{urlNode2.username}:{urlNode2.password}'
        headers = {"Authorization": f"Basic {str_to_b64str(authpair)}"}

        conn = http.client.HTTPConnection(urlNode2.hostname, urlNode2.port)
        conn.connect()
        conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
        out1 = conn.getresponse().read()
        assert b'"error":null' in out1
        assert conn.sock is not None  #connection must be closed because bitcoind should use keep-alive by default

        # Check excessive request size
        conn = http.client.HTTPConnection(urlNode2.hostname, urlNode2.port)
        conn.connect()
        conn.request('GET', f'/{"x"*1000}', '', headers)
        out1 = conn.getresponse()
        assert_equal(out1.status, http.client.NOT_FOUND)

        conn = http.client.HTTPConnection(urlNode2.hostname, urlNode2.port)
        conn.connect()
        conn.request('GET', f'/{"x"*10000}', '', headers)
        out1 = conn.getresponse()
        assert_equal(out1.status, http.client.BAD_REQUEST)


if __name__ == '__main__':
    HTTPBasicsTest(__file__).main()


Review comment (bug):
_Repeat comment https://github.com/bitcoin/bitcoin/pull/32061#discussion_r2090527952 here:_

Shouldn't this be `assert False`? Here the expectation is that the `recv()` will throw an exception due to timeout.

https://docs.python.org/3/library/socket.html#socket.socket.recv
> A returned empty bytes object indicates that the client has disconnected.

An "empty bytes object" will not trigger the assert `assert not res` but if that happens (= disconnect) then the test should fail.

suggestion:
```diff
-            assert not res
+            assert False
```

Code after:
        req += f'Authorization: Basic {str_to_b64str(authpair)}\r\n'

        # First request will take a long time to process
        body1 = f'{{"method": "waitforblockheight", "params": [{tip_height + 1}]}}'
        req1 = req
        req1 += f'Content-Length: {len(body1)}\r\n\r\n'
        req1 += body1

        # Second request will process very fast
        body2 = '{"method": "getblockcount"}'
        req2 = req
        req2 += f'Content-Length: {len(body2)}\r\n\r\n'
        req2 += body2
        # Get the underlying socket from HTTP connection so we can send something unusual
        conn = http.client.HTTPConnection(urlNode2.hostname, urlNode2.port)
        conn.connect()
        sock = conn.sock
        sock.settimeout(5)
        # Send two requests in a row. The first will block the second indefinitely
        sock.sendall(req1.encode("utf-8"))
        sock.sendall(req2.encode("utf-8"))
        try:
            # The server should not respond to the fast, second request
            # until the (very) slow first request has been handled:
            res = sock.recv(1024)
            assert False
        except TimeoutError:
            pass

        # Use a separate http connection to generate a block
        self.generate(self.nodes[2], 1, sync_fun=self.no_op)

        # Wait for two responses to be received
        res = b""
        while res.count(b"result") != 2:
            res += sock.recv(1024)

        # waitforblockheight was responded to first, and then getblockcount
        # which includes the block added after the request was made
        chunks = res.split(b'"result":')
        assert chunks[1].startswith(b'{"hash":')
        assert chunks[2].startswith(bytes(f'{tip_height + 1}', 'utf8'))


        self.log.info("Check HTTP request encoded with chunked transfer")
        headers_chunked = headers.copy()
        headers_chunked.update({"Transfer-encoding": "chunked"})
        body_chunked = [
            b'{"method": "submitblock", "params": ["',
            b'0' * 1000000,
            b'1' * 1000000,