summaryrefslogtreecommitdiffstats
path: root/samples/bpf/tcp_cong_kern.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /samples/bpf/tcp_cong_kern.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
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.c78
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 000000000..2311fc9dd
--- /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";