1d9925368SLawrence Brakmo /* Copyright (c) 2017 Facebook 2d9925368SLawrence Brakmo * 3d9925368SLawrence Brakmo * This program is free software; you can redistribute it and/or 4d9925368SLawrence Brakmo * modify it under the terms of version 2 of the GNU General Public 5d9925368SLawrence Brakmo * License as published by the Free Software Foundation. 6d9925368SLawrence Brakmo * 7d9925368SLawrence Brakmo * BPF program to set initial receive window to 40 packets and send 8d9925368SLawrence Brakmo * and receive buffers to 1.5MB. This would usually be done after 9d9925368SLawrence Brakmo * doing appropriate checks that indicate the hosts are far enough 10d9925368SLawrence Brakmo * away (i.e. large RTT). 11d9925368SLawrence Brakmo * 12d9925368SLawrence Brakmo * Use load_sock_ops to load this BPF program. 13d9925368SLawrence Brakmo */ 14d9925368SLawrence Brakmo 15d9925368SLawrence Brakmo #include <uapi/linux/bpf.h> 16d9925368SLawrence Brakmo #include <uapi/linux/if_ether.h> 17d9925368SLawrence Brakmo #include <uapi/linux/if_packet.h> 18d9925368SLawrence Brakmo #include <uapi/linux/ip.h> 19d9925368SLawrence Brakmo #include <linux/socket.h> 20d9925368SLawrence Brakmo #include "bpf_helpers.h" 21d9925368SLawrence Brakmo #include "bpf_endian.h" 22d9925368SLawrence Brakmo 23d9925368SLawrence Brakmo #define DEBUG 1 24d9925368SLawrence Brakmo 25d9925368SLawrence Brakmo #define bpf_printk(fmt, ...) \ 26d9925368SLawrence Brakmo ({ \ 27d9925368SLawrence Brakmo char ____fmt[] = fmt; \ 28d9925368SLawrence Brakmo bpf_trace_printk(____fmt, sizeof(____fmt), \ 29d9925368SLawrence Brakmo ##__VA_ARGS__); \ 30d9925368SLawrence Brakmo }) 31d9925368SLawrence Brakmo 32d9925368SLawrence Brakmo SEC("sockops") 33d9925368SLawrence Brakmo int bpf_bufs(struct bpf_sock_ops *skops) 34d9925368SLawrence Brakmo { 35d9925368SLawrence Brakmo int bufsize = 1500000; 36d9925368SLawrence Brakmo int rwnd_init = 40; 37d9925368SLawrence Brakmo int rv = 0; 38d9925368SLawrence Brakmo int op; 39d9925368SLawrence Brakmo 40d9925368SLawrence Brakmo /* For testing purposes, only execute rest of BPF program 41d9925368SLawrence Brakmo * if neither port numberis 55601 42d9925368SLawrence Brakmo */ 43d9925368SLawrence Brakmo if (bpf_ntohl(skops->remote_port) != 55601 && 44a4174f05SLawrence Brakmo skops->local_port != 55601) { 45a4174f05SLawrence Brakmo skops->reply = -1; 46a4174f05SLawrence Brakmo return 1; 47a4174f05SLawrence Brakmo } 48d9925368SLawrence Brakmo 49d9925368SLawrence Brakmo op = (int) skops->op; 50d9925368SLawrence Brakmo 51d9925368SLawrence Brakmo #ifdef DEBUG 52d9925368SLawrence Brakmo bpf_printk("Returning %d\n", rv); 53d9925368SLawrence Brakmo #endif 54d9925368SLawrence Brakmo 55d9925368SLawrence Brakmo /* Usually there would be a check to insure the hosts are far 56d9925368SLawrence Brakmo * from each other so it makes sense to increase buffer sizes 57d9925368SLawrence Brakmo */ 58d9925368SLawrence Brakmo switch (op) { 59d9925368SLawrence Brakmo case BPF_SOCK_OPS_RWND_INIT: 60d9925368SLawrence Brakmo rv = rwnd_init; 61d9925368SLawrence Brakmo break; 62d9925368SLawrence Brakmo case BPF_SOCK_OPS_TCP_CONNECT_CB: 63d9925368SLawrence Brakmo /* Set sndbuf and rcvbuf of active connections */ 64d9925368SLawrence Brakmo rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize, 65d9925368SLawrence Brakmo sizeof(bufsize)); 66a4174f05SLawrence Brakmo rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF, 67d9925368SLawrence Brakmo &bufsize, sizeof(bufsize)); 68d9925368SLawrence Brakmo break; 69d9925368SLawrence Brakmo case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: 70d9925368SLawrence Brakmo /* Nothing to do */ 71d9925368SLawrence Brakmo break; 72d9925368SLawrence Brakmo case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: 73d9925368SLawrence Brakmo /* Set sndbuf and rcvbuf of passive connections */ 74d9925368SLawrence Brakmo rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize, 75d9925368SLawrence Brakmo sizeof(bufsize)); 76a4174f05SLawrence Brakmo rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF, 77d9925368SLawrence Brakmo &bufsize, sizeof(bufsize)); 78d9925368SLawrence Brakmo break; 79d9925368SLawrence Brakmo default: 80d9925368SLawrence Brakmo rv = -1; 81d9925368SLawrence Brakmo } 82d9925368SLawrence Brakmo #ifdef DEBUG 83d9925368SLawrence Brakmo bpf_printk("Returning %d\n", rv); 84d9925368SLawrence Brakmo #endif 85d9925368SLawrence Brakmo skops->reply = rv; 86d9925368SLawrence Brakmo return 1; 87d9925368SLawrence Brakmo } 88d9925368SLawrence Brakmo char _license[] SEC("license") = "GPL"; 89