Implementations of the TCP and UDP networking protocol.
Projects for Cal State Fullerton's Computer Networking course(CPSC 471).
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Throughout the course, we covered networking concepts related to most of the layers of the open systems interconnection(OSI) model. With these three projects, we concentrated on the transport layer(i.e. layer 4). In a group of three, we implemented several programs with each project having a focus on a networking protocol or architecture. Related concepts: hashing algorithms, message digests, checksums
- Project-1-UDP: Implemented a file download program as the server under the user datagram protocol(UDP).
- Project-2-TCP: Implemented a file download program as the client under the transmission control protocol(TCP)
- Project-3-P2P: Implemented a file sharing program through a peer-to-peer network.
Languages: Python 3.x
Modules:
/Project-1-UDP/SectionServerUDP.py: Utilizing md5 hash as a checksum to verify the integrity of the data
def md5(section):
"""Returns 32 hexdigit of a string"""
this_section = section
new_string = ""
for x in range(len(this_section)):
new_string += chr(this_section[x])
m = hashlib.md5()
m.update(new_string.encode())
return m.hexdigest()/Project-2-TCP/SectionClientTCP.py: Acting as the client, we extract the metadata from the response of the server
def decode_list_response(list_response):
"""Takes in the response from a 'LIST' request, separates each category into a 5 element list, then
appends that list into the 'sections' list"""
lines = list_response.decode().splitlines()
expected_file_digest = lines.pop(0)
sections = []
total_file_size = 0
for line in lines:
columns = line.split(maxsplit=2)
section_num = int(columns[0])
beg_byte = int(section_num * MAX_SECTION_SIZE)
end_byte = int((section_num+1) * MAX_SECTION_SIZE)
section = list((columns[0], columns[1], columns[2], beg_byte, end_byte))
sections.append(section)
total_file_size += int(columns[1])
return expected_file_digest, sections, total_file_size/Project-3-P2P/SectionClientP2P.py: Multiplexing with selectors
while not download_complete:
for key, mask in sel.select(timeout=None):
connection = key.fileobj
data = key.data
if mask & selectors.EVENT_READ:
recv_data = connection.recv(1024)
if recv_data:
data.data[beg_byte:(beg_byte+len(recv_data))] = recv_data
beg_byte += len(recv_data)
else:
sel.unregister(connection)
connection.close()Download Python 3.x
- Clone the repo
git clone https://github.com/beaubadilla/cpsc471_computer_networking.git- Follow the README.md for each individual part.
Beau Jayme De Guzman Badilla - [email protected] - LinkedIn