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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /samples/bpf/tcp_cong_kern.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'samples/bpf/tcp_cong_kern.c')
-rw-r--r-- | samples/bpf/tcp_cong_kern.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/samples/bpf/tcp_cong_kern.c b/samples/bpf/tcp_cong_kern.c new file mode 100644 index 0000000000..2311fc9dde --- /dev/null +++ b/samples/bpf/tcp_cong_kern.c @@ -0,0 +1,78 @@ +/* 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 congestion control to dctcp when both hosts are + * in the same datacenter (as deteremined by IPv6 prefix). + * + * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program. + */ + +#include <uapi/linux/bpf.h> +#include <uapi/linux/tcp.h> +#include <uapi/linux/if_ether.h> +#include <uapi/linux/if_packet.h> +#include <uapi/linux/ip.h> +#include <linux/socket.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_endian.h> + +#define DEBUG 1 + +SEC("sockops") +int bpf_cong(struct bpf_sock_ops *skops) +{ + char cong[] = "dctcp"; + 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) { + skops->reply = -1; + return 1; + } + + op = (int) skops->op; + +#ifdef DEBUG + bpf_printk("BPF command: %d\n", op); +#endif + + /* Check if both hosts are in the same datacenter. For this + * example they are if the 1st 5.5 bytes in the IPv6 address + * are the same. + */ + if (skops->family == AF_INET6 && + skops->local_ip6[0] == skops->remote_ip6[0] && + (bpf_ntohl(skops->local_ip6[1]) & 0xfff00000) == + (bpf_ntohl(skops->remote_ip6[1]) & 0xfff00000)) { + switch (op) { + case BPF_SOCK_OPS_NEEDS_ECN: + rv = 1; + break; + case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: + rv = bpf_setsockopt(skops, SOL_TCP, TCP_CONGESTION, + cong, sizeof(cong)); + break; + case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: + rv = bpf_setsockopt(skops, SOL_TCP, TCP_CONGESTION, + cong, sizeof(cong)); + break; + default: + rv = -1; + } + } else { + rv = -1; + } +#ifdef DEBUG + bpf_printk("Returning %d\n", rv); +#endif + skops->reply = rv; + return 1; +} +char _license[] SEC("license") = "GPL"; |