Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) /* Copyright (c) 2017 Facebook
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * This program is free software; you can redistribute it and/or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  * modify it under the terms of version 2 of the GNU General Public
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * License as published by the Free Software Foundation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  * BPF program to set initial receive window to 40 packets when using IPv6
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  * and the first 5.5 bytes of the IPv6 addresses are not the same (in this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  * example that means both hosts are not the same datacenter).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <uapi/linux/bpf.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <uapi/linux/if_ether.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <uapi/linux/if_packet.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <uapi/linux/ip.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/socket.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <bpf/bpf_helpers.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <bpf/bpf_endian.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #define DEBUG 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) SEC("sockops")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) int bpf_rwnd(struct bpf_sock_ops *skops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	int rv = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	int op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	/* For testing purposes, only execute rest of BPF program
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	 * if neither port numberis 55601
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	if (bpf_ntohl(skops->remote_port) !=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	    55601 && skops->local_port != 55601) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 		skops->reply = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 		return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	op = (int) skops->op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #ifdef DEBUG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	bpf_printk("BPF command: %d\n", op);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 	/* Check for RWND_INIT operation and IPv6 addresses */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	if (op == BPF_SOCK_OPS_RWND_INIT &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 		skops->family == AF_INET6) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 		/* If the first 5.5 bytes of the IPv6 address are not the same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 		 * then both hosts are not in the same datacenter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 		 * so use a larger initial advertized window (40 packets)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 		if (skops->local_ip6[0] != skops->remote_ip6[0] ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 		    (bpf_ntohl(skops->local_ip6[1]) & 0xfffff000) !=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 		    (bpf_ntohl(skops->remote_ip6[1]) & 0xfffff000))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 			rv = 40;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) #ifdef DEBUG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 	bpf_printk("Returning %d\n", rv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 	skops->reply = rv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) char _license[] SEC("license") = "GPL";