Commit | Line | Data |
---|---|---|
7bc62e28 LB |
1 | /* Copyright (c) 2017 Facebook |
2 | * | |
3 | * This program is free software; you can redistribute it and/or | |
4 | * modify it under the terms of version 2 of the GNU General Public | |
5 | * License as published by the Free Software Foundation. | |
6 | * | |
7 | * BPF program to set initial congestion window and initial receive | |
8 | * window to 40 packets and send and receive buffers to 1.5MB. This | |
9 | * would usually be done after doing appropriate checks that indicate | |
10 | * the hosts are far enough away (i.e. large RTT). | |
11 | * | |
ea9b6362 | 12 | * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program. |
7bc62e28 LB |
13 | */ |
14 | ||
15 | #include <uapi/linux/bpf.h> | |
16 | #include <uapi/linux/if_ether.h> | |
17 | #include <uapi/linux/if_packet.h> | |
18 | #include <uapi/linux/ip.h> | |
19 | #include <linux/socket.h> | |
20 | #include "bpf_helpers.h" | |
21 | #include "bpf_endian.h" | |
22 | ||
23 | #define DEBUG 1 | |
24 | ||
7bc62e28 LB |
25 | SEC("sockops") |
26 | int bpf_iw(struct bpf_sock_ops *skops) | |
27 | { | |
28 | int bufsize = 1500000; | |
29 | int rwnd_init = 40; | |
30 | int iw = 40; | |
31 | int rv = 0; | |
32 | int op; | |
33 | ||
34 | /* For testing purposes, only execute rest of BPF program | |
35 | * if neither port numberis 55601 | |
36 | */ | |
37 | if (bpf_ntohl(skops->remote_port) != 55601 && | |
e1853319 LB |
38 | skops->local_port != 55601) { |
39 | skops->reply = -1; | |
40 | return 1; | |
41 | } | |
7bc62e28 LB |
42 | |
43 | op = (int) skops->op; | |
44 | ||
45 | #ifdef DEBUG | |
46 | bpf_printk("BPF command: %d\n", op); | |
47 | #endif | |
48 | ||
49 | /* Usually there would be a check to insure the hosts are far | |
50 | * from each other so it makes sense to increase buffer sizes | |
51 | */ | |
52 | switch (op) { | |
53 | case BPF_SOCK_OPS_RWND_INIT: | |
54 | rv = rwnd_init; | |
55 | break; | |
56 | case BPF_SOCK_OPS_TCP_CONNECT_CB: | |
57 | /* Set sndbuf and rcvbuf of active connections */ | |
58 | rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize, | |
59 | sizeof(bufsize)); | |
e1853319 LB |
60 | rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF, |
61 | &bufsize, sizeof(bufsize)); | |
7bc62e28 LB |
62 | break; |
63 | case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: | |
64 | rv = bpf_setsockopt(skops, SOL_TCP, TCP_BPF_IW, &iw, | |
65 | sizeof(iw)); | |
66 | break; | |
67 | case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: | |
68 | /* Set sndbuf and rcvbuf of passive connections */ | |
69 | rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize, | |
70 | sizeof(bufsize)); | |
e1853319 LB |
71 | rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF, |
72 | &bufsize, sizeof(bufsize)); | |
7bc62e28 LB |
73 | break; |
74 | default: | |
75 | rv = -1; | |
76 | } | |
77 | #ifdef DEBUG | |
78 | bpf_printk("Returning %d\n", rv); | |
79 | #endif | |
80 | skops->reply = rv; | |
81 | return 1; | |
82 | } | |
83 | char _license[] SEC("license") = "GPL"; |