From: Lawrence Brakmo <brakmo@fb•com>
To: netdev <netdev@vger•kernel.org>
Cc: Kernel Team <kernel-team@fb•com>, Blake Matheny <bmatheny@fb•com>,
Alexei Starovoitov <ast@fb•com>,
Daniel Borkmann <daniel@iogearbox•net>,
David Ahern <dsa@cumulusnetworks•com>
Subject: [RFC PATCH net-next v2 13/15] bpf: Sample BPF program to set initial cwnd
Date: Thu, 15 Jun 2017 13:08:42 -0700 [thread overview]
Message-ID: <20170615200844.2752485-14-brakmo@fb.com> (raw)
In-Reply-To: <20170615200844.2752485-1-brakmo@fb.com>
Sample BPF program that assumes hosts are far away (i.e. large RTTs)
and sets initial cwnd and initial receive window to 40 packets,
send and receive buffers to 1.5MB.
In practice there would be a test to insure the hosts are actually
far enough away.
Signed-off-by: Lawrence Brakmo <brakmo@fb•com>
---
samples/bpf/Makefile | 1 +
samples/bpf/tcp_iw_kern.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 74 insertions(+)
create mode 100644 samples/bpf/tcp_iw_kern.c
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index eb324e0..3ec96a0 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -117,6 +117,7 @@ always += tcp_synrto_kern.o
always += tcp_rwnd_kern.o
always += tcp_bufs_kern.o
always += tcp_cong_kern.o
+always += tcp_iw_kern.o
HOSTCFLAGS += -I$(objtree)/usr/include
HOSTCFLAGS += -I$(srctree)/tools/lib/
diff --git a/samples/bpf/tcp_iw_kern.c b/samples/bpf/tcp_iw_kern.c
new file mode 100644
index 0000000..07962c8
--- /dev/null
+++ b/samples/bpf/tcp_iw_kern.c
@@ -0,0 +1,73 @@
+/*
+ * BPF program to set initial congestion window and 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).
+ */
+
+#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"
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_iw(struct bpf_socket_ops *skops)
+{
+ char fmt1[] = "BPF command: %d\n";
+ char fmt2[] = " Returning %d\n";
+ int bufsize = 1500000;
+ int rwnd_init = 40;
+ int iw = 40;
+ int rv = 0;
+ int op;
+
+ /* For testing purposes, only execute rest of BPF program
+ * if neither port numberis 55601
+ */
+ if (skops->remote_port != 55601 && skops->local_port != 55601)
+ return -1;
+
+ op = (int) skops->op;
+
+#ifdef DEBUG
+ bpf_trace_printk(fmt1, sizeof(fmt1), op);
+#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_SOCKET_OPS_RWND_INIT:
+ rv = rwnd_init;
+ break;
+ case BPF_SOCKET_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_SOCKET_OPS_ACTIVE_ESTABLISHED_CB:
+ rv = bpf_setsockopt(skops, SOL_TCP, TCP_BPF_IW, &iw,
+ sizeof(iw));
+ break;
+ case BPF_SOCKET_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_trace_printk(fmt2, sizeof(fmt2), rv);
+#endif
+ return rv;
+}
+char _license[] SEC("license") = "GPL";
--
2.9.3
next prev parent reply other threads:[~2017-06-15 20:09 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-15 20:08 [RFC PATCH net-next v2 00/15] bpf: BPF support for socket ops Lawrence Brakmo
2017-06-15 20:08 ` [RFC PATCH net-next v2 01/15] " Lawrence Brakmo
2017-06-16 12:07 ` Daniel Borkmann
2017-06-16 23:41 ` Lawrence Brakmo
2017-06-19 18:44 ` Daniel Borkmann
2017-06-19 20:49 ` Lawrence Brakmo
2017-06-17 21:48 ` Lawrence Brakmo
2017-06-19 18:52 ` Daniel Borkmann
2017-06-19 20:49 ` Lawrence Brakmo
2017-06-15 20:08 ` [RFC PATCH net-next v2 02/15] bpf: program to load socketops BPF programs Lawrence Brakmo
2017-06-15 20:08 ` [RFC PATCH net-next v2 03/15] bpf: Support for per connection SYN/SYN-ACK RTOs Lawrence Brakmo
2017-06-15 20:08 ` [RFC PATCH net-next v2 04/15] bpf: Sample bpf program to set " Lawrence Brakmo
2017-06-15 20:08 ` [RFC PATCH net-next v2 05/15] bpf: Support for setting initial receive window Lawrence Brakmo
2017-06-15 20:08 ` [RFC PATCH net-next v2 06/15] bpf: Sample bpf program to set initial window Lawrence Brakmo
2017-06-15 20:08 ` [RFC PATCH net-next v2 07/15] bpf: Add setsockopt helper function to bpf Lawrence Brakmo
2017-06-16 13:27 ` Daniel Borkmann
2017-06-17 23:17 ` Lawrence Brakmo
2017-06-15 20:08 ` [RFC PATCH net-next v2 08/15] bpf: Add TCP connection BPF callbacks Lawrence Brakmo
2017-06-15 20:08 ` [RFC PATCH net-next v2 09/15] bpf: Sample BPF program to set buffer sizes Lawrence Brakmo
2017-06-15 20:08 ` [RFC PATCH net-next v2 10/15] bpf: Add support for changing congestion control Lawrence Brakmo
2017-06-16 13:58 ` Daniel Borkmann
2017-06-18 2:39 ` Lawrence Brakmo
2017-06-19 22:34 ` Daniel Borkmann
2017-06-20 0:35 ` Lawrence Brakmo
2017-06-15 20:08 ` [RFC PATCH net-next v2 11/15] bpf: Sample BPF program to set " Lawrence Brakmo
2017-06-15 20:08 ` [RFC PATCH net-next v2 12/15] bpf: Adds support for setting initial cwnd Lawrence Brakmo
2017-06-15 20:08 ` Lawrence Brakmo [this message]
2017-06-15 20:08 ` [RFC PATCH net-next v2 14/15] bpf: Adds support for setting sndcwnd clamp Lawrence Brakmo
2017-06-15 20:08 ` [RFC PATCH net-next v2 15/15] bpf: Sample bpf program to set " Lawrence Brakmo
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