Fix unable to get daddr from conn.log flow in flowalerts about stratospherelinuxips

[AlyaGomaa]

File:CTU-SME-11/CTU-SME-11/Experiment-VM-Linux-Ubuntu2204-1/2023-02-23/raw/2023-02-23-00-01-51-192.168.1.109.pcap
Branch: develop
Commit: c5fc002

File "/StratosphereLinuxIPS/slips_files/common/abstracts.py", line 115, in run

error: bool = self.main()

File "/StratosphereLinuxIPS/modules/flowalerts/flowalerts.py", line 2045, in main

self.detect_data_upload_in_twid(profileid, twid)

File "/StratosphereLinuxIPS/modules/flowalerts/flowalerts.py", line 417, in detect_data_upload_in_twid

bytes_sent: dict = get_sent_bytes(all_flows)

File "/StratosphereLinuxIPS/modules/flowalerts/flowalerts.py", line 399, in get_sent_bytes

if self.is_ignored_ip_data_upload(daddr) or not sbytes:

File "/StratosphereLinuxIPS/modules/flowalerts/flowalerts.py", line 280, in is_ignored_ip_data_upload

ip_obj = ipaddress.ip_address(ip)

File "/envs/slips/lib/python3.9/ipaddress.py", line 53, in ip_address

raise ValueError('%r does not appear to be an IPv4 or IPv6 address' %

ValueError: '' does not appear to be an IPv4 or IPv6 address