📚 Reti Peer To Peer - Università degli Studi di Ferrara 📚

A peer-to-peer server based on Kazaa's approach:

Smart Query flooding

Hierarchic

• Super-nodes managing their peers
• On startup, the client contacts a super-node (and may later become one)
• Publish: client sends list of files to its super-node
• Search: send query to super-node, and the super- nodes flood queries among themselves
• Fetch: get file directly from peer(s); can fetch from multiple peers at once

Functioning

• Each peer is either a group leader or assigned to a group leader
• Group leader tracks the content in all its children

Motivation for super-nodes

• Query consolidation ** Many connected nodes may have only a few files ** Propagating query to a sub-node may take more time than for the super-node to answer itself
• Stability ** Super-node selection favors nodes with high up-time ** How long you’ve been on is a good predictor of how long you’ll be around in the future

python3 AlaKazaam.py

Note: Python 3.6 or above is required

[xxxB] = the parameter length in bytes

# Search a Supernode
SUPE[4B].Pktid[16B].IPP2P[55B].PP2P[5B].TTL[2B]
# Response will be
ASUP[4B].Pktid[16B].IPP2P[55B].PP2P[5B]

# Login
LOGI[4B].IPP2P[55B].PP2P[5B]
# Response will be
ALGI[4B].SessionID[16B]

# Add a file
ADFF[4B].SessionID[16B].Filemd5[32B].Filename[100B]
# No response from the server

# Remove a file
DEFF[4B].SessionID[16B].Filemd5[32B]
# No response from the server

# Logout
LOGO[4B].SessionID[16B]
# Response will be
ALGO[4B].\#delete[3B]

# Search a file
QUER[4B].Pktid[16B].IPP2P[55B].PP2P[5B].TTL[2B].Ricerca[20B]
# Response will be
AQUE[4B].Pktid[16B].IPP2P[55B].PP2P[5B].Filemd5[32B].Filename[100B]

# Choose a file among the supernodes
FIND[4B].SessionID[16B].Ricerca[20B]
# Response will be
AFIN[4B].\#idmd5[3B].{Filemd5_i[32B].Filename_i[100B].\#copy_i[3B].{IPP2P_i_j[55B].PP2P_i_j[5B]}(j=1..\#copy_i)}(i=1..\#idmd5)

# Retrieve a file
RETR[4B].Filemd5[16B]
# Response will be
ARET[4B].\#chunk[6B].{Lenchunk_i[5B].data[LB]}(i=1..\#chunk)

• Federico Frigo
• Niccolò Fontana
• Giovanni Fiorini
• Marco Rambaldi

Enjoy 😎