1 files changed, 64 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/test_pkt_access.c b/tools/testing/selftests/bpf/test_pkt_access.c
new file mode 100644
index 000000000000..fd1e0832d409
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_pkt_access.c
@@ -0,0 +1,64 @@
+/* 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.
+ */
+#include <stddef.h>
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/pkt_cls.h>
+#include "bpf_helpers.h"
+
+#define _htons __builtin_bswap16
+#define barrier() __asm__ __volatile__("": : :"memory")
+int _version SEC("version") = 1;
+
+SEC("test1")
+int process(struct __sk_buff *skb)
+{
+	void *data_end = (void *)(long)skb->data_end;
+	void *data = (void *)(long)skb->data;
+	struct ethhdr *eth = (struct ethhdr *)(data);
+	struct tcphdr *tcp = NULL;
+	__u8 proto = 255;
+	__u64 ihl_len;
+
+	if (eth + 1 > data_end)
+		return TC_ACT_SHOT;
+
+	if (eth->h_proto == _htons(ETH_P_IP)) {
+		struct iphdr *iph = (struct iphdr *)(eth + 1);
+
+		if (iph + 1 > data_end)
+			return TC_ACT_SHOT;
+		ihl_len = iph->ihl * 4;
+		proto = iph->protocol;
+		tcp = (struct tcphdr *)((void *)(iph) + ihl_len);
+	} else if (eth->h_proto == _htons(ETH_P_IPV6)) {
+		struct ipv6hdr *ip6h = (struct ipv6hdr *)(eth + 1);
+
+		if (ip6h + 1 > data_end)
+			return TC_ACT_SHOT;
+		ihl_len = sizeof(*ip6h);
+		proto = ip6h->nexthdr;
+		tcp = (struct tcphdr *)((void *)(ip6h) + ihl_len);
+	}
+
+	if (tcp) {
+		if (((void *)(tcp) + 20) > data_end || proto != 6)
+			return TC_ACT_SHOT;
+		barrier(); /* to force ordering of checks */
+		if (((void *)(tcp) + 18) > data_end)
+			return TC_ACT_SHOT;
+		if (tcp->urg_ptr == 123)
+			return TC_ACT_OK;
+	}
+
+	return TC_ACT_UNSPEC;
+}