vera:net

TCP/UDP socket operations.

import "vera:net"

Overview

Provides portable socket operations for TCP and UDP clients and servers. All functions are built on compiler primitives (__vera_sys_*) which the compiler maps to platform-specific networking APIs (POSIX sockets on Linux/macOS, Winsock on Windows).

Dependencies: None (uses primitives directly)

Constants

These are VERA-portable values. The compiler maps them to platform equivalents.

Functions

Socket Creation

tcp_socket

function tcp_socket() -> i32

Create a TCP (stream) socket using IPv4.

Returns: socket file descriptor, or -1 on error

udp_socket

function udp_socket() -> i32

Create a UDP (datagram) socket using IPv4.

Returns: socket file descriptor, or -1 on error

Client Operations

tcp_connect

function tcp_connect(fd: i32, ip: ptr, ip_len: i32, port: i32) -> i32

Connect a socket to an IPv4 address and port. The IP address must be a null-terminated string (e.g., "127.0.0.1\0").

Parameters:

• fd (i32) — socket file descriptor
• ip (ptr) — null-terminated IPv4 address string
• ip_len (i32) — length of the IP string including the null terminator
• port (i32) — port number to connect to

Returns: 0 on success, -1 on error

Server Operations

tcp_bind

function tcp_bind(fd: i32, ip: ptr, ip_len: i32, port: i32) -> i32

Bind a socket to an IPv4 address and port. The IP address must be a null-terminated string; use "0.0.0.0\0" to bind to all interfaces.

Parameters:

• fd (i32) — socket file descriptor
• ip (ptr) — null-terminated IPv4 address string
• ip_len (i32) — length of the IP string including the null terminator
• port (i32) — port number to bind to

Returns: 0 on success, -1 on error

tcp_listen

function tcp_listen(fd: i32, backlog: i32) -> i32

Start listening for incoming connections on a bound socket.

Parameters:

• fd (i32) — socket file descriptor (must be bound)
• backlog (i32) — maximum length of the pending connection queue

Returns: 0 on success, -1 on error

tcp_accept

function tcp_accept(fd: i32) -> i32

Accept an incoming connection on a listening socket. Blocks until a connection arrives.

Parameters:

• fd (i32) — listening socket file descriptor

Returns: new client socket file descriptor, or -1 on error

Data Transfer

socket_send

function socket_send(fd: i32, data: ptr, length: i64) -> i64

Send data on a connected socket.

Parameters:

• fd (i32) — socket file descriptor
• data (ptr) — pointer to the data to send
• length (i64) — number of bytes to send

Returns: number of bytes sent, or -1 on error

socket_recv

function socket_recv(fd: i32, buffer: ptr, max_length: i64) -> i64

Receive data from a connected socket into a buffer.

Parameters:

• fd (i32) — socket file descriptor
• buffer (ptr) — pointer to the buffer to receive into
• max_length (i64) — maximum number of bytes to receive

Returns: number of bytes received, 0 for EOF (peer closed connection), or -1 on error

Socket Management

socket_close

function socket_close(fd: i32) -> i32

Close a socket.

Parameters:

• fd (i32) — socket file descriptor

Returns: 0 on success, or a negative value on error

socket_shutdown

function socket_shutdown(fd: i32, how: i32) -> i32

Shut down part of a socket connection.

Parameters:

• fd (i32) — socket file descriptor
• how (i32) — shutdown mode: 0 = stop reading, 1 = stop writing, 2 = stop both

Returns: 0 on success, or a negative value on error

socket_poll

function socket_poll(fd: i32, events: i32, timeout_ms: i32) -> i32

Poll a socket for readiness.

Parameters:

• fd (i32) — socket file descriptor
• events (i32) — bitmask of what to check: 1 = readable, 2 = writable, 3 = both
• timeout_ms (i32) — milliseconds to wait (-1 = block forever, 0 = non-blocking check)

Returns: bitmask of ready events (1 = readable, 2 = writable), 0 on timeout, -1 on error

set_reuseaddr

function set_reuseaddr(fd: i32) -> i32

Enable SO_REUSEADDR on a socket. Useful for servers to avoid "address already in use" errors when restarting.

Parameters:

• fd (i32) — socket file descriptor

Returns: 0 on success