| #!/usr/bin/env python3 |
| # SPDX-License-Identifier: GPL-2.0 |
| |
| """ |
| tdc_gso.py - send a UDP GSO datagram |
| |
| Copyright (C) 2026 Xingquan Liu <b1n@b1n.io> |
| """ |
| |
| import argparse |
| import socket |
| import struct |
| import sys |
| |
| UDP_MAX_SEGMENTS = 1 << 7 |
| |
| |
| parser = argparse.ArgumentParser(description="UDP GSO datagram sender") |
| parser.add_argument("src", help="source IPv4 address") |
| parser.add_argument("dst", help="destination IPv4 address") |
| parser.add_argument("port", type=int, help="destination UDP port") |
| parser.add_argument("gso_size", type=int, help="UDP GSO segment payload size") |
| parser.add_argument("payload_len", type=int, help="total UDP payload length") |
| args = parser.parse_args() |
| |
| if args.gso_size <= 0 or args.gso_size > 0xFFFF: |
| parser.error("gso_size must fit in an unsigned 16-bit integer") |
| if args.payload_len <= args.gso_size: |
| parser.error("payload_len must be larger than gso_size") |
| if args.payload_len > args.gso_size * UDP_MAX_SEGMENTS: |
| parser.error("payload_len exceeds UDP_MAX_SEGMENTS") |
| |
| SOL_UDP = getattr(socket, "SOL_UDP", socket.IPPROTO_UDP) |
| UDP_SEGMENT = getattr(socket, "UDP_SEGMENT", 103) |
| |
| sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) |
| sock.bind((args.src, 0)) |
| |
| payload = b"b" * args.payload_len |
| cmsg = [(SOL_UDP, UDP_SEGMENT, struct.pack("=H", args.gso_size))] |
| |
| sent = sock.sendmsg([payload], cmsg, 0, (args.dst, args.port)) |
| sys.exit(sent != len(payload)) |
