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d9925368 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 receive window to 40 packets and send | |
8 | * and receive buffers to 1.5MB. This would usually be done after | |
9 | * doing appropriate checks that indicate the hosts are far enough | |
10 | * away (i.e. large RTT). | |
11 | * | |
12 | * Use load_sock_ops to load this BPF program. | |
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 | ||
25 | #define bpf_printk(fmt, ...) \ | |
26 | ({ \ | |
27 | char ____fmt[] = fmt; \ | |
28 | bpf_trace_printk(____fmt, sizeof(____fmt), \ | |
29 | ##__VA_ARGS__); \ | |
30 | }) | |
31 | ||
32 | SEC("sockops") | |
33 | int bpf_bufs(struct bpf_sock_ops *skops) | |
34 | { | |
35 | int bufsize = 1500000; | |
36 | int rwnd_init = 40; | |
37 | int rv = 0; | |
38 | int op; | |
39 | ||
40 | /* For testing purposes, only execute rest of BPF program | |
41 | * if neither port numberis 55601 | |
42 | */ | |
43 | if (bpf_ntohl(skops->remote_port) != 55601 && | |
44 | skops->local_port != 55601) | |
45 | return -1; | |
46 | ||
47 | op = (int) skops->op; | |
48 | ||
49 | #ifdef DEBUG | |
50 | bpf_printk("Returning %d\n", rv); | |
51 | #endif | |
52 | ||
53 | /* Usually there would be a check to insure the hosts are far | |
54 | * from each other so it makes sense to increase buffer sizes | |
55 | */ | |
56 | switch (op) { | |
57 | case BPF_SOCK_OPS_RWND_INIT: | |
58 | rv = rwnd_init; | |
59 | break; | |
60 | case BPF_SOCK_OPS_TCP_CONNECT_CB: | |
61 | /* Set sndbuf and rcvbuf of active connections */ | |
62 | rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize, | |
63 | sizeof(bufsize)); | |
64 | rv = rv*100 + bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF, | |
65 | &bufsize, sizeof(bufsize)); | |
66 | break; | |
67 | case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: | |
68 | /* Nothing to do */ | |
69 | break; | |
70 | case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: | |
71 | /* Set sndbuf and rcvbuf of passive connections */ | |
72 | rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize, | |
73 | sizeof(bufsize)); | |
74 | rv = rv*100 + bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF, | |
75 | &bufsize, sizeof(bufsize)); | |
76 | break; | |
77 | default: | |
78 | rv = -1; | |
79 | } | |
80 | #ifdef DEBUG | |
81 | bpf_printk("Returning %d\n", rv); | |
82 | #endif | |
83 | skops->reply = rv; | |
84 | return 1; | |
85 | } | |
86 | char _license[] SEC("license") = "GPL"; |