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	bpftool can do all the things load_sock_ops used to do, and more. Point users to bpftool instead of maintaining this sample utility. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
		
			
				
	
	
		
			88 lines
		
	
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			88 lines
		
	
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* Copyright (c) 2017 Facebook
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of version 2 of the GNU General Public
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 * License as published by the Free Software Foundation.
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 *
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 * BPF program to set initial receive window to 40 packets and send
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 * and receive buffers to 1.5MB. This would usually be done after
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 * doing appropriate checks that indicate the hosts are far enough
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 * away (i.e. large RTT).
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 *
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 * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
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 */
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#include <uapi/linux/bpf.h>
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#include <uapi/linux/if_ether.h>
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#include <uapi/linux/if_packet.h>
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#include <uapi/linux/ip.h>
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#include <linux/socket.h>
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#include "bpf_helpers.h"
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#include "bpf_endian.h"
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#define DEBUG 1
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#define bpf_printk(fmt, ...)					\
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({								\
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	       char ____fmt[] = fmt;				\
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	       bpf_trace_printk(____fmt, sizeof(____fmt),	\
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				##__VA_ARGS__);			\
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})
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SEC("sockops")
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int bpf_bufs(struct bpf_sock_ops *skops)
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{
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	int bufsize = 1500000;
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	int rwnd_init = 40;
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	int rv = 0;
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	int op;
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	/* For testing purposes, only execute rest of BPF program
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	 * if neither port numberis 55601
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	 */
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	if (bpf_ntohl(skops->remote_port) != 55601 &&
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	    skops->local_port != 55601) {
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		skops->reply = -1;
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		return 1;
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	}
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	op = (int) skops->op;
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#ifdef DEBUG
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	bpf_printk("Returning %d\n", rv);
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#endif
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	/* Usually there would be a check to insure the hosts are far
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	 * from each other so it makes sense to increase buffer sizes
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	 */
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	switch (op) {
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	case BPF_SOCK_OPS_RWND_INIT:
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		rv = rwnd_init;
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		break;
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	case BPF_SOCK_OPS_TCP_CONNECT_CB:
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		/* Set sndbuf and rcvbuf of active connections */
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		rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
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				    sizeof(bufsize));
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		rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
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				     &bufsize, sizeof(bufsize));
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		break;
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	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
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		/* Nothing to do */
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		break;
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	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
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		/* Set sndbuf and rcvbuf of passive connections */
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		rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
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				    sizeof(bufsize));
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		rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
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				     &bufsize, sizeof(bufsize));
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		break;
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	default:
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		rv = -1;
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	}
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#ifdef DEBUG
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	bpf_printk("Returning %d\n", rv);
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#endif
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	skops->reply = rv;
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	return 1;
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}
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char _license[] SEC("license") = "GPL";
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