wolfIP is a new lightweight TCP/IP stack designed for resource-constrained embedded systems that eliminates dynamic memory allocations entirely. The project, developed by wolfSSL Inc., provides BSD-like non-blocking socket APIs with custom callbacks and supports endpoint-only mode for establishing network connections without routing between interfaces.

Built with fixed concurrent sockets and pre-allocated buffers in static memory, wolfIP implements comprehensive protocol support including Ethernet II, ARP, IPv4 with optional forwarding, ICMP, UDP, and TCP with advanced features like SACK, congestion control, and TCP timestamps. The stack also includes application-layer protocols such as DHCP client, DNS queries, and HTTP/HTTPS server with wolfSSL TLS integration.

Developers can test wolfIP using a POSIX shim that redirects socket calls through LD_PRELOAD to a TAP device, enabling validation with standard tools like netcat and ping. The project also includes a FreeRTOS port with background task management and mutex-protected socket access. Licensed under GPLv3, wolfIP represents a significant advancement for embedded networking where memory predictability and real-time performance are critical requirements.