def test_prefix_cuts_message(kresd_sock, datalen, send_query):
"""Prefix is shorter than the DNS message."""
wire, _ = utils.prepare_wire()
assert datalen < len(wire)
invalid_buff = utils.prepare_buffer(wire, datalen)
send_query(kresd_sock, invalid_buff) # buffer breaks parsing of TCP stream
with utils.expect_kresd_close():
utils.ping_alive(kresd_sock)
def test_prefix_trailing_garbage(kresd_sock, glength, query_before):
"""Send messages with trailing garbage (its length included in prefix)."""
if query_before:
utils.ping_alive(kresd_sock)
for _ in range(10):
wire, msgid = utils.prepare_wire()
wire += utils.get_garbage(glength)
buff = utils.prepare_buffer(wire)
kresd_sock.sendall(buff)
answer = utils.receive_parse_answer(kresd_sock)
assert answer.id == msgid
time.sleep(0.1)
def test_prefix_greater_than_message(kresd_sock, send_query):
"""Prefix is greater than the length of the entire DNS message."""
wire, invalid_msgid = utils.prepare_wire()
datalen = len(wire) + 16
invalid_buff = utils.prepare_buffer(wire, datalen)
send_query(kresd_sock, invalid_buff)
valid_buff, _ = utils.get_msgbuff()
kresd_sock.sendall(valid_buff)
# invalid_buff is answered (treats additional data as trailing garbage)
answer = utils.receive_parse_answer(kresd_sock)
assert answer.id == invalid_msgid
# parsing stream is broken by the invalid_buff, valid query is never answered
with utils.expect_kresd_close():
utils.receive_parse_answer(kresd_sock)