Files
android/samples/bpf/tcp_bufs_kern.c
T
threeeye bc1d038eac REVVL 6 Pro kernel bring-up: full working tree snapshot (2026-09-12)
Squashed backup commit (no shallow-clone history issues) of
xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2 branch, upstream
commit 9eece662e) plus all fixes applied to get everpal_defconfig building
clean against a modern (GCC 15.2.0) toolchain -- see the previous commit
message on the lineage-23.2 branch (also in this repo history is not
available here since this is a squashed snapshot; full incremental history
lives in the local DL380 checkout and the upstream GitHub remote).

Upstream: https://github.com/xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2)
2026-09-12 13:36:46 +00:00

87 lines
2.2 KiB
C

/* Copyright (c) 2017 Facebook
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* BPF program to set initial receive window to 40 packets and send
* and receive buffers to 1.5MB. This would usually be done after
* doing appropriate checks that indicate the hosts are far enough
* away (i.e. large RTT).
*
* Use load_sock_ops to load this BPF program.
*/
#include <uapi/linux/bpf.h>
#include <uapi/linux/if_ether.h>
#include <uapi/linux/if_packet.h>
#include <uapi/linux/ip.h>
#include <linux/socket.h>
#include "bpf_helpers.h"
#include "bpf_endian.h"
#define DEBUG 1
#define bpf_printk(fmt, ...) \
({ \
char ____fmt[] = fmt; \
bpf_trace_printk(____fmt, sizeof(____fmt), \
##__VA_ARGS__); \
})
SEC("sockops")
int bpf_bufs(struct bpf_sock_ops *skops)
{
int bufsize = 1500000;
int rwnd_init = 40;
int rv = 0;
int op;
/* For testing purposes, only execute rest of BPF program
* if neither port numberis 55601
*/
if (bpf_ntohl(skops->remote_port) != 55601 &&
skops->local_port != 55601)
return -1;
op = (int) skops->op;
#ifdef DEBUG
bpf_printk("Returning %d\n", rv);
#endif
/* Usually there would be a check to insure the hosts are far
* from each other so it makes sense to increase buffer sizes
*/
switch (op) {
case BPF_SOCK_OPS_RWND_INIT:
rv = rwnd_init;
break;
case BPF_SOCK_OPS_TCP_CONNECT_CB:
/* Set sndbuf and rcvbuf of active connections */
rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
sizeof(bufsize));
rv = rv*100 + bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
&bufsize, sizeof(bufsize));
break;
case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
/* Nothing to do */
break;
case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
/* Set sndbuf and rcvbuf of passive connections */
rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
sizeof(bufsize));
rv = rv*100 + bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
&bufsize, sizeof(bufsize));
break;
default:
rv = -1;
}
#ifdef DEBUG
bpf_printk("Returning %d\n", rv);
#endif
skops->reply = rv;
return 1;
}
char _license[] SEC("license") = "GPL";