Linux-libre 4.8.2-gnupck-4.8.2-gnu

14 files changed, 927 insertions, 2 deletions

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 0bf2478cb..90ebf7d35 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -14,12 +14,16 @@ hostprogs-y += tracex3
 hostprogs-y += tracex4
 hostprogs-y += tracex5
 hostprogs-y += tracex6
+hostprogs-y += test_probe_write_user
 hostprogs-y += trace_output
 hostprogs-y += lathist
 hostprogs-y += offwaketime
 hostprogs-y += spintest
 hostprogs-y += map_perf_test
 hostprogs-y += test_overhead
+hostprogs-y += test_cgrp2_array_pin
+hostprogs-y += xdp1
+hostprogs-y += xdp2
 
 test_verifier-objs := test_verifier.o libbpf.o
 test_maps-objs := test_maps.o libbpf.o
@@ -34,12 +38,17 @@ tracex3-objs := bpf_load.o libbpf.o tracex3_user.o
 tracex4-objs := bpf_load.o libbpf.o tracex4_user.o
 tracex5-objs := bpf_load.o libbpf.o tracex5_user.o
 tracex6-objs := bpf_load.o libbpf.o tracex6_user.o
+test_probe_write_user-objs := bpf_load.o libbpf.o test_probe_write_user_user.o
 trace_output-objs := bpf_load.o libbpf.o trace_output_user.o
 lathist-objs := bpf_load.o libbpf.o lathist_user.o
 offwaketime-objs := bpf_load.o libbpf.o offwaketime_user.o
 spintest-objs := bpf_load.o libbpf.o spintest_user.o
 map_perf_test-objs := bpf_load.o libbpf.o map_perf_test_user.o
 test_overhead-objs := bpf_load.o libbpf.o test_overhead_user.o
+test_cgrp2_array_pin-objs := libbpf.o test_cgrp2_array_pin.o
+xdp1-objs := bpf_load.o libbpf.o xdp1_user.o
+# reuse xdp1 source intentionally
+xdp2-objs := bpf_load.o libbpf.o xdp1_user.o
 
 # Tell kbuild to always build the programs
 always := $(hostprogs-y)
@@ -52,6 +61,7 @@ always += tracex3_kern.o
 always += tracex4_kern.o
 always += tracex5_kern.o
 always += tracex6_kern.o
+always += test_probe_write_user_kern.o
 always += trace_output_kern.o
 always += tcbpf1_kern.o
 always += lathist_kern.o
@@ -61,6 +71,9 @@ always += map_perf_test_kern.o
 always += test_overhead_tp_kern.o
 always += test_overhead_kprobe_kern.o
 always += parse_varlen.o parse_simple.o parse_ldabs.o
+always += test_cgrp2_tc_kern.o
+always += xdp1_kern.o
+always += xdp2_kern.o
 
 HOSTCFLAGS += -I$(objtree)/usr/include
 
@@ -75,12 +88,15 @@ HOSTLOADLIBES_tracex3 += -lelf
 HOSTLOADLIBES_tracex4 += -lelf -lrt
 HOSTLOADLIBES_tracex5 += -lelf
 HOSTLOADLIBES_tracex6 += -lelf
+HOSTLOADLIBES_test_probe_write_user += -lelf
 HOSTLOADLIBES_trace_output += -lelf -lrt
 HOSTLOADLIBES_lathist += -lelf
 HOSTLOADLIBES_offwaketime += -lelf
 HOSTLOADLIBES_spintest += -lelf
 HOSTLOADLIBES_map_perf_test += -lelf -lrt
 HOSTLOADLIBES_test_overhead += -lelf -lrt
+HOSTLOADLIBES_xdp1 += -lelf
+HOSTLOADLIBES_xdp2 += -lelf
 
 # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
 #  make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
diff --git a/samples/bpf/bpf_helpers.h b/samples/bpf/bpf_helpers.h
index 7904a2a49..7927a090f 100644
--- a/samples/bpf/bpf_helpers.h
+++ b/samples/bpf/bpf_helpers.h
@@ -41,6 +41,8 @@ static int (*bpf_perf_event_output)(void *ctx, void *map, int index, void *data,
 	(void *) BPF_FUNC_perf_event_output;
 static int (*bpf_get_stackid)(void *ctx, void *map, int flags) =
 	(void *) BPF_FUNC_get_stackid;
+static int (*bpf_probe_write_user)(void *dst, void *src, int size) =
+	(void *) BPF_FUNC_probe_write_user;
 
 /* llvm builtin functions that eBPF C program may use to
  * emit BPF_LD_ABS and BPF_LD_IND instructions
@@ -70,6 +72,8 @@ static int (*bpf_l3_csum_replace)(void *ctx, int off, int from, int to, int flag
 	(void *) BPF_FUNC_l3_csum_replace;
 static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flags) =
 	(void *) BPF_FUNC_l4_csum_replace;
+static int (*bpf_skb_under_cgroup)(void *ctx, void *map, int index) =
+	(void *) BPF_FUNC_skb_under_cgroup;
 
 #if defined(__x86_64__)
 
diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c
index 022af71c2..0cfda2320 100644
--- a/samples/bpf/bpf_load.c
+++ b/samples/bpf/bpf_load.c
@@ -50,6 +50,7 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
 	bool is_kprobe = strncmp(event, "kprobe/", 7) == 0;
 	bool is_kretprobe = strncmp(event, "kretprobe/", 10) == 0;
 	bool is_tracepoint = strncmp(event, "tracepoint/", 11) == 0;
+	bool is_xdp = strncmp(event, "xdp", 3) == 0;
 	enum bpf_prog_type prog_type;
 	char buf[256];
 	int fd, efd, err, id;
@@ -66,6 +67,8 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
 		prog_type = BPF_PROG_TYPE_KPROBE;
 	} else if (is_tracepoint) {
 		prog_type = BPF_PROG_TYPE_TRACEPOINT;
+	} else if (is_xdp) {
+		prog_type = BPF_PROG_TYPE_XDP;
 	} else {
 		printf("Unknown event '%s'\n", event);
 		return -1;
@@ -79,6 +82,9 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
 
 	prog_fd[prog_cnt++] = fd;
 
+	if (is_xdp)
+		return 0;
+
 	if (is_socket) {
 		event += 6;
 		if (*event != '/')
@@ -319,6 +325,7 @@ int load_bpf_file(char *path)
 			if (memcmp(shname_prog, "kprobe/", 7) == 0 ||
 			    memcmp(shname_prog, "kretprobe/", 10) == 0 ||
 			    memcmp(shname_prog, "tracepoint/", 11) == 0 ||
+			    memcmp(shname_prog, "xdp", 3) == 0 ||
 			    memcmp(shname_prog, "socket", 6) == 0)
 				load_and_attach(shname_prog, insns, data_prog->d_size);
 		}
@@ -336,6 +343,7 @@ int load_bpf_file(char *path)
 		if (memcmp(shname, "kprobe/", 7) == 0 ||
 		    memcmp(shname, "kretprobe/", 10) == 0 ||
 		    memcmp(shname, "tracepoint/", 11) == 0 ||
+		    memcmp(shname, "xdp", 3) == 0 ||
 		    memcmp(shname, "socket", 6) == 0)
 			load_and_attach(shname, data->d_buf, data->d_size);
 	}
diff --git a/samples/bpf/sockex2_user.c b/samples/bpf/sockex2_user.c
index 29a276d76..8a4085c2d 100644
--- a/samples/bpf/sockex2_user.c
+++ b/samples/bpf/sockex2_user.c
@@ -5,6 +5,7 @@
 #include "bpf_load.h"
 #include <unistd.h>
 #include <arpa/inet.h>
+#include <sys/resource.h>
 
 struct pair {
 	__u64 packets;
@@ -13,11 +14,13 @@ struct pair {
 
 int main(int ac, char **argv)
 {
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 	char filename[256];
 	FILE *f;
 	int i, sock;
 
 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	setrlimit(RLIMIT_MEMLOCK, &r);
 
 	if (load_bpf_file(filename)) {
 		printf("%s", bpf_log_buf);
diff --git a/samples/bpf/sockex3_user.c b/samples/bpf/sockex3_user.c
index 2617772d0..d4184ab5f 100644
--- a/samples/bpf/sockex3_user.c
+++ b/samples/bpf/sockex3_user.c
@@ -5,6 +5,7 @@
 #include "bpf_load.h"
 #include <unistd.h>
 #include <arpa/inet.h>
+#include <sys/resource.h>
 
 struct flow_keys {
 	__be32 src;
@@ -23,11 +24,13 @@ struct pair {
 
 int main(int argc, char **argv)
 {
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 	char filename[256];
 	FILE *f;
 	int i, sock;
 
 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	setrlimit(RLIMIT_MEMLOCK, &r);
 
 	if (load_bpf_file(filename)) {
 		printf("%s", bpf_log_buf);
diff --git a/samples/bpf/test_cgrp2_array_pin.c b/samples/bpf/test_cgrp2_array_pin.c
new file mode 100644
index 000000000..70e86f7be
--- /dev/null
+++ b/samples/bpf/test_cgrp2_array_pin.c
@@ -0,0 +1,109 @@
+/* Copyright (c) 2016 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 <linux/unistd.h>
+#include <linux/bpf.h>
+
+#include <stdio.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#include "libbpf.h"
+
+static void usage(void)
+{
+	printf("Usage: test_cgrp2_array_pin [...]\n");
+	printf("       -F <file>   File to pin an BPF cgroup array\n");
+	printf("       -U <file>   Update an already pinned BPF cgroup array\n");
+	printf("       -v <value>  Full path of the cgroup2\n");
+	printf("       -h          Display this help\n");
+}
+
+int main(int argc, char **argv)
+{
+	const char *pinned_file = NULL, *cg2 = NULL;
+	int create_array = 1;
+	int array_key = 0;
+	int array_fd = -1;
+	int cg2_fd = -1;
+	int ret = -1;
+	int opt;
+
+	while ((opt = getopt(argc, argv, "F:U:v:")) != -1) {
+		switch (opt) {
+		/* General args */
+		case 'F':
+			pinned_file = optarg;
+			break;
+		case 'U':
+			pinned_file = optarg;
+			create_array = 0;
+			break;
+		case 'v':
+			cg2 = optarg;
+			break;
+		default:
+			usage();
+			goto out;
+		}
+	}
+
+	if (!cg2 || !pinned_file) {
+		usage();
+		goto out;
+	}
+
+	cg2_fd = open(cg2, O_RDONLY);
+	if (cg2_fd < 0) {
+		fprintf(stderr, "open(%s,...): %s(%d)\n",
+			cg2, strerror(errno), errno);
+		goto out;
+	}
+
+	if (create_array) {
+		array_fd = bpf_create_map(BPF_MAP_TYPE_CGROUP_ARRAY,
+					  sizeof(uint32_t), sizeof(uint32_t),
+					  1, 0);
+		if (array_fd < 0) {
+			fprintf(stderr,
+				"bpf_create_map(BPF_MAP_TYPE_CGROUP_ARRAY,...): %s(%d)\n",
+				strerror(errno), errno);
+			goto out;
+		}
+	} else {
+		array_fd = bpf_obj_get(pinned_file);
+		if (array_fd < 0) {
+			fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
+				pinned_file, strerror(errno), errno);
+			goto out;
+		}
+	}
+
+	ret = bpf_update_elem(array_fd, &array_key, &cg2_fd, 0);
+	if (ret) {
+		perror("bpf_update_elem");
+		goto out;
+	}
+
+	if (create_array) {
+		ret = bpf_obj_pin(array_fd, pinned_file);
+		if (ret) {
+			fprintf(stderr, "bpf_obj_pin(..., %s): %s(%d)\n",
+				pinned_file, strerror(errno), errno);
+			goto out;
+		}
+	}
+
+out:
+	if (array_fd != -1)
+		close(array_fd);
+	if (cg2_fd != -1)
+		close(cg2_fd);
+	return ret;
+}
diff --git a/samples/bpf/test_cgrp2_tc.sh b/samples/bpf/test_cgrp2_tc.sh
new file mode 100755
index 000000000..0b119eeaf
--- /dev/null
+++ b/samples/bpf/test_cgrp2_tc.sh
@@ -0,0 +1,184 @@
+#!/bin/bash
+
+MY_DIR=$(dirname $0)
+# Details on the bpf prog
+BPF_CGRP2_ARRAY_NAME='test_cgrp2_array_pin'
+BPF_PROG="$MY_DIR/test_cgrp2_tc_kern.o"
+BPF_SECTION='filter'
+
+[ -z "$TC" ] && TC='tc'
+[ -z "$IP" ] && IP='ip'
+
+# Names of the veth interface, net namespace...etc.
+HOST_IFC='ve'
+NS_IFC='vens'
+NS='ns'
+
+find_mnt() {
+    cat /proc/mounts | \
+	awk '{ if ($3 == "'$1'" && mnt == "") { mnt = $2 }} END { print mnt }'
+}
+
+# Init cgroup2 vars
+init_cgrp2_vars() {
+    CGRP2_ROOT=$(find_mnt cgroup2)
+    if [ -z "$CGRP2_ROOT" ]
+    then
+	CGRP2_ROOT='/mnt/cgroup2'
+	MOUNT_CGRP2="yes"
+    fi
+    CGRP2_TC="$CGRP2_ROOT/tc"
+    CGRP2_TC_LEAF="$CGRP2_TC/leaf"
+}
+
+# Init bpf fs vars
+init_bpf_fs_vars() {
+    local bpf_fs_root=$(find_mnt bpf)
+    [ -n "$bpf_fs_root" ] || return -1
+    BPF_FS_TC_SHARE="$bpf_fs_root/tc/globals"
+}
+
+setup_cgrp2() {
+    case $1 in
+	start)
+	    if [ "$MOUNT_CGRP2" == 'yes' ]
+	    then
+		[ -d $CGRP2_ROOT ] || mkdir -p $CGRP2_ROOT
+		mount -t cgroup2 none $CGRP2_ROOT || return $?
+	    fi
+	    mkdir -p $CGRP2_TC_LEAF
+	    ;;
+	*)
+	    rmdir $CGRP2_TC_LEAF && rmdir $CGRP2_TC
+	    [ "$MOUNT_CGRP2" == 'yes' ] && umount $CGRP2_ROOT
+	    ;;
+    esac
+}
+
+setup_bpf_cgrp2_array() {
+    local bpf_cgrp2_array="$BPF_FS_TC_SHARE/$BPF_CGRP2_ARRAY_NAME"
+    case $1 in
+	start)
+	    $MY_DIR/test_cgrp2_array_pin -U $bpf_cgrp2_array -v $CGRP2_TC
+	    ;;
+	*)
+	    [ -d "$BPF_FS_TC_SHARE" ] && rm -f $bpf_cgrp2_array
+	    ;;
+    esac
+}
+
+setup_net() {
+    case $1 in
+	start)
+	    $IP link add $HOST_IFC type veth peer name $NS_IFC || return $?
+	    $IP link set dev $HOST_IFC up || return $?
+	    sysctl -q net.ipv6.conf.$HOST_IFC.accept_dad=0
+
+	    $IP netns add ns || return $?
+	    $IP link set dev $NS_IFC netns ns || return $?
+	    $IP -n $NS link set dev $NS_IFC up || return $?
+	    $IP netns exec $NS sysctl -q net.ipv6.conf.$NS_IFC.accept_dad=0
+	    $TC qdisc add dev $HOST_IFC clsact || return $?
+	    $TC filter add dev $HOST_IFC egress bpf da obj $BPF_PROG sec $BPF_SECTION || return $?
+	    ;;
+	*)
+	    $IP netns del $NS
+	    $IP link del $HOST_IFC
+	    ;;
+    esac
+}
+
+run_in_cgrp() {
+    # Fork another bash and move it under the specified cgroup.
+    # It makes the cgroup cleanup easier at the end of the test.
+    cmd='echo $$ > '
+    cmd="$cmd $1/cgroup.procs; exec $2"
+    bash -c "$cmd"
+}
+
+do_test() {
+    run_in_cgrp $CGRP2_TC_LEAF "ping -6 -c3 ff02::1%$HOST_IFC >& /dev/null"
+    local dropped=$($TC -s qdisc show dev $HOST_IFC | tail -3 | \
+			   awk '/drop/{print substr($7, 0, index($7, ",")-1)}')
+    if [[ $dropped -eq 0 ]]
+    then
+	echo "FAIL"
+	return 1
+    else
+	echo "Successfully filtered $dropped packets"
+	return 0
+    fi
+}
+
+do_exit() {
+    if [ "$DEBUG" == "yes" ] && [ "$MODE" != 'cleanuponly' ]
+    then
+	echo "------ DEBUG ------"
+	echo "mount: "; mount | egrep '(cgroup2|bpf)'; echo
+	echo "$CGRP2_TC_LEAF: "; ls -l $CGRP2_TC_LEAF; echo
+	if [ -d "$BPF_FS_TC_SHARE" ]
+	then
+	    echo "$BPF_FS_TC_SHARE: "; ls -l $BPF_FS_TC_SHARE; echo
+	fi
+	echo "Host net:"
+	$IP netns
+	$IP link show dev $HOST_IFC
+	$IP -6 a show dev $HOST_IFC
+	$TC -s qdisc show dev $HOST_IFC
+	echo
+	echo "$NS net:"
+	$IP -n $NS link show dev $NS_IFC
+	$IP -n $NS -6 link show dev $NS_IFC
+	echo "------ DEBUG ------"
+	echo
+    fi
+
+    if [ "$MODE" != 'nocleanup' ]
+    then
+	setup_net stop
+	setup_bpf_cgrp2_array stop
+	setup_cgrp2 stop
+    fi
+}
+
+init_cgrp2_vars
+init_bpf_fs_vars
+
+while [[ $# -ge 1 ]]
+do
+    a="$1"
+    case $a in
+	debug)
+	    DEBUG='yes'
+	    shift 1
+	    ;;
+	cleanup-only)
+	    MODE='cleanuponly'
+	    shift 1
+	    ;;
+	no-cleanup)
+	    MODE='nocleanup'
+	    shift 1
+	    ;;
+	*)
+	    echo "test_cgrp2_tc [debug] [cleanup-only | no-cleanup]"
+	    echo "  debug: Print cgrp and network setup details at the end of the test"
+	    echo "  cleanup-only: Try to cleanup things from last test.  No test will be run"
+	    echo "  no-cleanup: Run the test but don't do cleanup at the end"
+	    echo "[Note: If no arg is given, it will run the test and do cleanup at the end]"
+	    echo
+	    exit -1
+	    ;;
+    esac
+done
+
+trap do_exit 0
+
+[ "$MODE" == 'cleanuponly' ] && exit
+
+setup_cgrp2 start || exit $?
+setup_net start || exit $?
+init_bpf_fs_vars || exit $?
+setup_bpf_cgrp2_array start || exit $?
+do_test
+echo
diff --git a/samples/bpf/test_cgrp2_tc_kern.c b/samples/bpf/test_cgrp2_tc_kern.c
new file mode 100644
index 000000000..10ff73404
--- /dev/null
+++ b/samples/bpf/test_cgrp2_tc_kern.c
@@ -0,0 +1,69 @@
+/* Copyright (c) 2016 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 <uapi/linux/if_ether.h>
+#include <uapi/linux/in6.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/pkt_cls.h>
+#include <uapi/linux/bpf.h>
+#include "bpf_helpers.h"
+
+/* copy of 'struct ethhdr' without __packed */
+struct eth_hdr {
+	unsigned char   h_dest[ETH_ALEN];
+	unsigned char   h_source[ETH_ALEN];
+	unsigned short  h_proto;
+};
+
+#define PIN_GLOBAL_NS		2
+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") test_cgrp2_array_pin = {
+	.type		= BPF_MAP_TYPE_CGROUP_ARRAY,
+	.size_key	= sizeof(uint32_t),
+	.size_value	= sizeof(uint32_t),
+	.pinning	= PIN_GLOBAL_NS,
+	.max_elem	= 1,
+};
+
+SEC("filter")
+int handle_egress(struct __sk_buff *skb)
+{
+	void *data = (void *)(long)skb->data;
+	struct eth_hdr *eth = data;
+	struct ipv6hdr *ip6h = data + sizeof(*eth);
+	void *data_end = (void *)(long)skb->data_end;
+	char dont_care_msg[] = "dont care %04x %d\n";
+	char pass_msg[] = "pass\n";
+	char reject_msg[] = "reject\n";
+
+	/* single length check */
+	if (data + sizeof(*eth) + sizeof(*ip6h) > data_end)
+		return TC_ACT_OK;
+
+	if (eth->h_proto != htons(ETH_P_IPV6) ||
+	    ip6h->nexthdr != IPPROTO_ICMPV6) {
+		bpf_trace_printk(dont_care_msg, sizeof(dont_care_msg),
+				 eth->h_proto, ip6h->nexthdr);
+		return TC_ACT_OK;
+	} else if (bpf_skb_under_cgroup(skb, &test_cgrp2_array_pin, 0) != 1) {
+		bpf_trace_printk(pass_msg, sizeof(pass_msg));
+		return TC_ACT_OK;
+	} else {
+		bpf_trace_printk(reject_msg, sizeof(reject_msg));
+		return TC_ACT_SHOT;
+	}
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/test_maps.c b/samples/bpf/test_maps.c
index 47bf0858f..cce2b5975 100644
--- a/samples/bpf/test_maps.c
+++ b/samples/bpf/test_maps.c
@@ -68,7 +68,16 @@ static void test_hashmap_sanity(int i, void *data)
 	assert(bpf_update_elem(map_fd, &key, &value, BPF_NOEXIST) == -1 &&
 	       errno == E2BIG);
 
+	/* update existing element, thought the map is full */
+	key = 1;
+	assert(bpf_update_elem(map_fd, &key, &value, BPF_EXIST) == 0);
+	key = 2;
+	assert(bpf_update_elem(map_fd, &key, &value, BPF_ANY) == 0);
+	key = 1;
+	assert(bpf_update_elem(map_fd, &key, &value, BPF_ANY) == 0);
+
 	/* check that key = 0 doesn't exist */
+	key = 0;
 	assert(bpf_delete_elem(map_fd, &key) == -1 && errno == ENOENT);
 
 	/* iterate over two elements */
@@ -413,10 +422,12 @@ static void do_work(int fn, void *data)
 
 	for (i = fn; i < MAP_SIZE; i += TASKS) {
 		key = value = i;
-		if (do_update)
+		if (do_update) {
 			assert(bpf_update_elem(map_fd, &key, &value, BPF_NOEXIST) == 0);
-		else
+			assert(bpf_update_elem(map_fd, &key, &value, BPF_EXIST) == 0);
+		} else {
 			assert(bpf_delete_elem(map_fd, &key) == 0);
+		}
 	}
 }
 
diff --git a/samples/bpf/test_probe_write_user_kern.c b/samples/bpf/test_probe_write_user_kern.c
new file mode 100644
index 000000000..3a677c807
--- /dev/null
+++ b/samples/bpf/test_probe_write_user_kern.c
@@ -0,0 +1,52 @@
+/* Copyright (c) 2016 Sargun Dhillon <sargun@sargun.me>
+ *
+ * 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 <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <uapi/linux/bpf.h>
+#include <linux/version.h>
+#include "bpf_helpers.h"
+
+struct bpf_map_def SEC("maps") dnat_map = {
+	.type = BPF_MAP_TYPE_HASH,
+	.key_size = sizeof(struct sockaddr_in),
+	.value_size = sizeof(struct sockaddr_in),
+	.max_entries = 256,
+};
+
+/* kprobe is NOT a stable ABI
+ * kernel functions can be removed, renamed or completely change semantics.
+ * Number of arguments and their positions can change, etc.
+ * In such case this bpf+kprobe example will no longer be meaningful
+ *
+ * This example sits on a syscall, and the syscall ABI is relatively stable
+ * of course, across platforms, and over time, the ABI may change.
+ */
+SEC("kprobe/sys_connect")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	struct sockaddr_in new_addr, orig_addr = {};
+	struct sockaddr_in *mapped_addr;
+	void *sockaddr_arg = (void *)PT_REGS_PARM2(ctx);
+	int sockaddr_len = (int)PT_REGS_PARM3(ctx);
+
+	if (sockaddr_len > sizeof(orig_addr))
+		return 0;
+
+	if (bpf_probe_read(&orig_addr, sizeof(orig_addr), sockaddr_arg) != 0)
+		return 0;
+
+	mapped_addr = bpf_map_lookup_elem(&dnat_map, &orig_addr);
+	if (mapped_addr != NULL) {
+		memcpy(&new_addr, mapped_addr, sizeof(new_addr));
+		bpf_probe_write_user(sockaddr_arg, &new_addr,
+				     sizeof(new_addr));
+	}
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/test_probe_write_user_user.c b/samples/bpf/test_probe_write_user_user.c
new file mode 100644
index 000000000..a44bf347b
--- /dev/null
+++ b/samples/bpf/test_probe_write_user_user.c
@@ -0,0 +1,78 @@
+#include <stdio.h>
+#include <assert.h>
+#include <linux/bpf.h>
+#include <unistd.h>
+#include "libbpf.h"
+#include "bpf_load.h"
+#include <sys/socket.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+int main(int ac, char **argv)
+{
+	int serverfd, serverconnfd, clientfd;
+	socklen_t sockaddr_len;
+	struct sockaddr serv_addr, mapped_addr, tmp_addr;
+	struct sockaddr_in *serv_addr_in, *mapped_addr_in, *tmp_addr_in;
+	char filename[256];
+	char *ip;
+
+	serv_addr_in = (struct sockaddr_in *)&serv_addr;
+	mapped_addr_in = (struct sockaddr_in *)&mapped_addr;
+	tmp_addr_in = (struct sockaddr_in *)&tmp_addr;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	if (load_bpf_file(filename)) {
+		printf("%s", bpf_log_buf);
+		return 1;
+	}
+
+	assert((serverfd = socket(AF_INET, SOCK_STREAM, 0)) > 0);
+	assert((clientfd = socket(AF_INET, SOCK_STREAM, 0)) > 0);
+
+	/* Bind server to ephemeral port on lo */
+	memset(&serv_addr, 0, sizeof(serv_addr));
+	serv_addr_in->sin_family = AF_INET;
+	serv_addr_in->sin_port = 0;
+	serv_addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+	assert(bind(serverfd, &serv_addr, sizeof(serv_addr)) == 0);
+
+	sockaddr_len = sizeof(serv_addr);
+	assert(getsockname(serverfd, &serv_addr, &sockaddr_len) == 0);
+	ip = inet_ntoa(serv_addr_in->sin_addr);
+	printf("Server bound to: %s:%d\n", ip, ntohs(serv_addr_in->sin_port));
+
+	memset(&mapped_addr, 0, sizeof(mapped_addr));
+	mapped_addr_in->sin_family = AF_INET;
+	mapped_addr_in->sin_port = htons(5555);
+	mapped_addr_in->sin_addr.s_addr = inet_addr("255.255.255.255");
+
+	assert(!bpf_update_elem(map_fd[0], &mapped_addr, &serv_addr, BPF_ANY));
+
+	assert(listen(serverfd, 5) == 0);
+
+	ip = inet_ntoa(mapped_addr_in->sin_addr);
+	printf("Client connecting to: %s:%d\n",
+	       ip, ntohs(mapped_addr_in->sin_port));
+	assert(connect(clientfd, &mapped_addr, sizeof(mapped_addr)) == 0);
+
+	sockaddr_len = sizeof(tmp_addr);
+	ip = inet_ntoa(tmp_addr_in->sin_addr);
+	assert((serverconnfd = accept(serverfd, &tmp_addr, &sockaddr_len)) > 0);
+	printf("Server received connection from: %s:%d\n",
+	       ip, ntohs(tmp_addr_in->sin_port));
+
+	sockaddr_len = sizeof(tmp_addr);
+	assert(getpeername(clientfd, &tmp_addr, &sockaddr_len) == 0);
+	ip = inet_ntoa(tmp_addr_in->sin_addr);
+	printf("Client's peer address: %s:%d\n",
+	       ip, ntohs(tmp_addr_in->sin_port));
+
+	/* Is the server's getsockname = the socket getpeername */
+	assert(memcmp(&serv_addr, &tmp_addr, sizeof(struct sockaddr_in)) == 0);
+
+	return 0;
+}
diff --git a/samples/bpf/xdp1_kern.c b/samples/bpf/xdp1_kern.c
new file mode 100644
index 000000000..219742106
--- /dev/null
+++ b/samples/bpf/xdp1_kern.c
@@ -0,0 +1,93 @@
+/* Copyright (c) 2016 PLUMgrid
+ *
+ * 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.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include "bpf_helpers.h"
+
+struct bpf_map_def SEC("maps") rxcnt = {
+	.type = BPF_MAP_TYPE_PERCPU_ARRAY,
+	.key_size = sizeof(u32),
+	.value_size = sizeof(long),
+	.max_entries = 256,
+};
+
+static int parse_ipv4(void *data, u64 nh_off, void *data_end)
+{
+	struct iphdr *iph = data + nh_off;
+
+	if (iph + 1 > data_end)
+		return 0;
+	return iph->protocol;
+}
+
+static int parse_ipv6(void *data, u64 nh_off, void *data_end)
+{
+	struct ipv6hdr *ip6h = data + nh_off;
+
+	if (ip6h + 1 > data_end)
+		return 0;
+	return ip6h->nexthdr;
+}
+
+SEC("xdp1")
+int xdp_prog1(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	int rc = XDP_DROP;
+	long *value;
+	u16 h_proto;
+	u64 nh_off;
+	u32 ipproto;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end)
+		return rc;
+
+	h_proto = eth->h_proto;
+
+	if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return rc;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+	if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return rc;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+
+	if (h_proto == htons(ETH_P_IP))
+		ipproto = parse_ipv4(data, nh_off, data_end);
+	else if (h_proto == htons(ETH_P_IPV6))
+		ipproto = parse_ipv6(data, nh_off, data_end);
+	else
+		ipproto = 0;
+
+	value = bpf_map_lookup_elem(&rxcnt, &ipproto);
+	if (value)
+		*value += 1;
+
+	return rc;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp1_user.c b/samples/bpf/xdp1_user.c
new file mode 100644
index 000000000..a5e109e39
--- /dev/null
+++ b/samples/bpf/xdp1_user.c
@@ -0,0 +1,181 @@
+/* Copyright (c) 2016 PLUMgrid
+ *
+ * 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 <linux/bpf.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include "bpf_load.h"
+#include "libbpf.h"
+
+static int set_link_xdp_fd(int ifindex, int fd)
+{
+	struct sockaddr_nl sa;
+	int sock, seq = 0, len, ret = -1;
+	char buf[4096];
+	struct nlattr *nla, *nla_xdp;
+	struct {
+		struct nlmsghdr  nh;
+		struct ifinfomsg ifinfo;
+		char             attrbuf[64];
+	} req;
+	struct nlmsghdr *nh;
+	struct nlmsgerr *err;
+
+	memset(&sa, 0, sizeof(sa));
+	sa.nl_family = AF_NETLINK;
+
+	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+	if (sock < 0) {
+		printf("open netlink socket: %s\n", strerror(errno));
+		return -1;
+	}
+
+	if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
+		printf("bind to netlink: %s\n", strerror(errno));
+		goto cleanup;
+	}
+
+	memset(&req, 0, sizeof(req));
+	req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
+	req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
+	req.nh.nlmsg_type = RTM_SETLINK;
+	req.nh.nlmsg_pid = 0;
+	req.nh.nlmsg_seq = ++seq;
+	req.ifinfo.ifi_family = AF_UNSPEC;
+	req.ifinfo.ifi_index = ifindex;
+	nla = (struct nlattr *)(((char *)&req)
+				+ NLMSG_ALIGN(req.nh.nlmsg_len));
+	nla->nla_type = NLA_F_NESTED | 43/*IFLA_XDP*/;
+
+	nla_xdp = (struct nlattr *)((char *)nla + NLA_HDRLEN);
+	nla_xdp->nla_type = 1/*IFLA_XDP_FD*/;
+	nla_xdp->nla_len = NLA_HDRLEN + sizeof(int);
+	memcpy((char *)nla_xdp + NLA_HDRLEN, &fd, sizeof(fd));
+	nla->nla_len = NLA_HDRLEN + nla_xdp->nla_len;
+
+	req.nh.nlmsg_len += NLA_ALIGN(nla->nla_len);
+
+	if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) {
+		printf("send to netlink: %s\n", strerror(errno));
+		goto cleanup;
+	}
+
+	len = recv(sock, buf, sizeof(buf), 0);
+	if (len < 0) {
+		printf("recv from netlink: %s\n", strerror(errno));
+		goto cleanup;
+	}
+
+	for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
+	     nh = NLMSG_NEXT(nh, len)) {
+		if (nh->nlmsg_pid != getpid()) {
+			printf("Wrong pid %d, expected %d\n",
+			       nh->nlmsg_pid, getpid());
+			goto cleanup;
+		}
+		if (nh->nlmsg_seq != seq) {
+			printf("Wrong seq %d, expected %d\n",
+			       nh->nlmsg_seq, seq);
+			goto cleanup;
+		}
+		switch (nh->nlmsg_type) {
+		case NLMSG_ERROR:
+			err = (struct nlmsgerr *)NLMSG_DATA(nh);
+			if (!err->error)
+				continue;
+			printf("nlmsg error %s\n", strerror(-err->error));
+			goto cleanup;
+		case NLMSG_DONE:
+			break;
+		}
+	}
+
+	ret = 0;
+
+cleanup:
+	close(sock);
+	return ret;
+}
+
+static int ifindex;
+
+static void int_exit(int sig)
+{
+	set_link_xdp_fd(ifindex, -1);
+	exit(0);
+}
+
+/* simple per-protocol drop counter
+ */
+static void poll_stats(int interval)
+{
+	unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+	const unsigned int nr_keys = 256;
+	__u64 values[nr_cpus], prev[nr_keys][nr_cpus];
+	__u32 key;
+	int i;
+
+	memset(prev, 0, sizeof(prev));
+
+	while (1) {
+		sleep(interval);
+
+		for (key = 0; key < nr_keys; key++) {
+			__u64 sum = 0;
+
+			assert(bpf_lookup_elem(map_fd[0], &key, values) == 0);
+			for (i = 0; i < nr_cpus; i++)
+				sum += (values[i] - prev[key][i]);
+			if (sum)
+				printf("proto %u: %10llu pkt/s\n",
+				       key, sum / interval);
+			memcpy(prev[key], values, sizeof(values));
+		}
+	}
+}
+
+int main(int ac, char **argv)
+{
+	char filename[256];
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	if (ac != 2) {
+		printf("usage: %s IFINDEX\n", argv[0]);
+		return 1;
+	}
+
+	ifindex = strtoul(argv[1], NULL, 0);
+
+	if (load_bpf_file(filename)) {
+		printf("%s", bpf_log_buf);
+		return 1;
+	}
+
+	if (!prog_fd[0]) {
+		printf("load_bpf_file: %s\n", strerror(errno));
+		return 1;
+	}
+
+	signal(SIGINT, int_exit);
+
+	if (set_link_xdp_fd(ifindex, prog_fd[0]) < 0) {
+		printf("link set xdp fd failed\n");
+		return 1;
+	}
+
+	poll_stats(2);
+
+	return 0;
+}
diff --git a/samples/bpf/xdp2_kern.c b/samples/bpf/xdp2_kern.c
new file mode 100644
index 000000000..e01288867
--- /dev/null
+++ b/samples/bpf/xdp2_kern.c
@@ -0,0 +1,114 @@
+/* Copyright (c) 2016 PLUMgrid
+ *
+ * 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.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include "bpf_helpers.h"
+
+struct bpf_map_def SEC("maps") rxcnt = {
+	.type = BPF_MAP_TYPE_PERCPU_ARRAY,
+	.key_size = sizeof(u32),
+	.value_size = sizeof(long),
+	.max_entries = 256,
+};
+
+static void swap_src_dst_mac(void *data)
+{
+	unsigned short *p = data;
+	unsigned short dst[3];
+
+	dst[0] = p[0];
+	dst[1] = p[1];
+	dst[2] = p[2];
+	p[0] = p[3];
+	p[1] = p[4];
+	p[2] = p[5];
+	p[3] = dst[0];
+	p[4] = dst[1];
+	p[5] = dst[2];
+}
+
+static int parse_ipv4(void *data, u64 nh_off, void *data_end)
+{
+	struct iphdr *iph = data + nh_off;
+
+	if (iph + 1 > data_end)
+		return 0;
+	return iph->protocol;
+}
+
+static int parse_ipv6(void *data, u64 nh_off, void *data_end)
+{
+	struct ipv6hdr *ip6h = data + nh_off;
+
+	if (ip6h + 1 > data_end)
+		return 0;
+	return ip6h->nexthdr;
+}
+
+SEC("xdp1")
+int xdp_prog1(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	int rc = XDP_DROP;
+	long *value;
+	u16 h_proto;
+	u64 nh_off;
+	u32 ipproto;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end)
+		return rc;
+
+	h_proto = eth->h_proto;
+
+	if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return rc;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+	if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return rc;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+
+	if (h_proto == htons(ETH_P_IP))
+		ipproto = parse_ipv4(data, nh_off, data_end);
+	else if (h_proto == htons(ETH_P_IPV6))
+		ipproto = parse_ipv6(data, nh_off, data_end);
+	else
+		ipproto = 0;
+
+	value = bpf_map_lookup_elem(&rxcnt, &ipproto);
+	if (value)
+		*value += 1;
+
+	if (ipproto == IPPROTO_UDP) {
+		swap_src_dst_mac(data);
+		rc = XDP_TX;
+	}
+
+	return rc;
+}
+
+char _license[] SEC("license") = "GPL";