Day54 - UNIX Domain Socket Advanced IPC

Today I explored advanced Linux AF_UNIX IPC features.

Implemented:

• Abstract namespace UNIX socket
• SOCK_DGRAM local IPC
• Datagram request/reply
• Peer credential retrieval
• UID-based authorization
• Datagram truncation detection

Key observations:

• Abstract sockets do not require filesystem entries
• SO_PEERCRED enables Linux local IPC authentication
• SOCK_DGRAM preserves message boundaries
• Datagram packets are truncated instead of split
• DGRAM communication differs significantly from STREAM semantics

I also compared:

• SOCK_STREAM
• SOCK_DGRAM

and learned their architecture differences.

The most important concept today was understanding:

STREAM = byte stream
DGRAM  = packet transport

I also observed how Linux daemon architectures commonly use:

• Abstract namespace sockets
• Credential-based authorization

for local IPC security.

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