From f74599f7c5309b21151233b98139e9b723fd1110 Mon Sep 17 00:00:00 2001
From: Thomas Graf <tgraf@suug.ch>
Date: Wed, 30 Nov 2016 17:10:11 +0100
Subject: bpf: Add tests and samples for LWT-BPF
Adds a series of tests to verify the functionality of attaching
BPF programs at LWT hooks.
Also adds a sample which collects a histogram of packet sizes which
pass through an LWT hook.
$ ./lwt_len_hist.sh
Starting netserver with host 'IN(6)ADDR_ANY' port '12865' and family AF_UNSPEC
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.253.2 () port 0 AF_INET : demo
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
87380 16384 16384 10.00 39857.69
1 -> 1 : 0 | |
2 -> 3 : 0 | |
4 -> 7 : 0 | |
8 -> 15 : 0 | |
16 -> 31 : 0 | |
32 -> 63 : 22 | |
64 -> 127 : 98 | |
128 -> 255 : 213 | |
256 -> 511 : 1444251 |******** |
512 -> 1023 : 660610 |*** |
1024 -> 2047 : 535241 |** |
2048 -> 4095 : 19 | |
4096 -> 8191 : 180 | |
8192 -> 16383 : 5578023 |************************************* |
16384 -> 32767 : 632099 |*** |
32768 -> 65535 : 6575 | |
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
samples/bpf/lwt_len_hist_kern.c | 82 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 82 insertions(+)
create mode 100644 samples/bpf/lwt_len_hist_kern.c
(limited to 'samples/bpf/lwt_len_hist_kern.c')
diff --git a/samples/bpf/lwt_len_hist_kern.c b/samples/bpf/lwt_len_hist_kern.c
new file mode 100644
index 000000000000..df75383280f9
--- /dev/null
+++ b/samples/bpf/lwt_len_hist_kern.c
@@ -0,0 +1,82 @@
+/* Copyright (c) 2016 Thomas Graf <tgraf@tgraf.ch>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/in.h>
+#include "bpf_helpers.h"
+
+# define printk(fmt, ...) \
+ ({ \
+ char ____fmt[] = fmt; \
+ bpf_trace_printk(____fmt, sizeof(____fmt), \
+ ##__VA_ARGS__); \
+ })
+
+struct bpf_elf_map {
+ __u32 type;
+ __u32 size_key;
+ __u32 size_value;
+ __u32 max_elem;
+ __u32 flags;
+ __u32 id;
+ __u32 pinning;
+};
+
+struct bpf_elf_map SEC("maps") lwt_len_hist_map = {
+ .type = BPF_MAP_TYPE_PERCPU_HASH,
+ .size_key = sizeof(__u64),
+ .size_value = sizeof(__u64),
+ .pinning = 2,
+ .max_elem = 1024,
+};
+
+static unsigned int log2(unsigned int v)
+{
+ unsigned int r;
+ unsigned int shift;
+
+ r = (v > 0xFFFF) << 4; v >>= r;
+ shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
+ shift = (v > 0xF) << 2; v >>= shift; r |= shift;
+ shift = (v > 0x3) << 1; v >>= shift; r |= shift;
+ r |= (v >> 1);
+ return r;
+}
+
+static unsigned int log2l(unsigned long v)
+{
+ unsigned int hi = v >> 32;
+ if (hi)
+ return log2(hi) + 32;
+ else
+ return log2(v);
+}
+
+SEC("len_hist")
+int do_len_hist(struct __sk_buff *skb)
+{
+ __u64 *value, key, init_val = 1;
+
+ key = log2l(skb->len);
+
+ value = bpf_map_lookup_elem(&lwt_len_hist_map, &key);
+ if (value)
+ __sync_fetch_and_add(value, 1);
+ else
+ bpf_map_update_elem(&lwt_len_hist_map, &key, &init_val, BPF_ANY);
+
+ return BPF_OK;
+}
+
+char _license[] SEC("license") = "GPL";
--
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