Demystifying Zero-Copy I/O and Modern TLS Tuning

High-throughput network services often spend disproportionate CPU cycles copying buffers between kernel space and user space.

The Splice and Sendfile Primitives

By leveraging splice(2):

ssize_t splice(int fd_in, loff_t *off_in, int fd_out,
               loff_t *off_out, size_t len, unsigned int flags);

Data flows directly between pipe buffers and socket descriptors without crossing the kernel-user memory boundary.

TLS Handshake Padding and Post-Quantum Extensions

With post-quantum key exchange algorithms like ML-DSA-65 and Kyber gaining adoption, TLS handshake record sizes increase substantially. Ensuring that certificate chains and padding calculations provide sufficient headroom prevents subtle MTU fragmentation issues across heterogeneous network links.