Commit 66fc4ca8 authored by Kumar Kartikeya Dwivedi's avatar Kumar Kartikeya Dwivedi Committed by Alexei Starovoitov
Browse files

samples: bpf: Convert xdp_redirect_kern.o to XDP samples helper 



We moved swap_src_dst_mac to xdp_sample.bpf.h to be shared with other
potential users, so drop it while moving code to the new file.
Also, consistently use SEC("xdp") naming instead.

Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-16-memxor@gmail.com
parent 6e1051a5

samples/bpf/Makefile

+3 −2
Original line number Diff line number Diff line
@@ -163,7 +163,6 @@ always-y += tcp_clamp_kern.o 
always-y += tcp_basertt_kern.o

always-y += tcp_tos_reflect_kern.o

always-y += tcp_dumpstats_kern.o

always-y += xdp_redirect_kern.o

always-y += xdp_redirect_map_kern.o

always-y += xdp_redirect_map_multi_kern.o

always-y += xdp_redirect_cpu_kern.o
@@ -356,6 +355,7 @@ endef 


CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG))



$(obj)/xdp_redirect.bpf.o: $(obj)/xdp_sample.bpf.o

$(obj)/xdp_monitor.bpf.o: $(obj)/xdp_sample.bpf.o



$(obj)/%.bpf.o: $(src)/%.bpf.c $(obj)/vmlinux.h $(src)/xdp_sample.bpf.h $(src)/xdp_sample_shared.h
@@ -366,9 +366,10 @@ $(obj)/%.bpf.o: $(src)/%.bpf.c $(obj)/vmlinux.h $(src)/xdp_sample.bpf.h $(src)/x 
		-I$(srctree)/tools/lib $(CLANG_SYS_INCLUDES) \

		-c $(filter %.bpf.c,$^) -o $@



LINKED_SKELS := xdp_monitor.skel.h

LINKED_SKELS := xdp_redirect.skel.h xdp_monitor.skel.h

clean-files += $(LINKED_SKELS)



xdp_redirect.skel.h-deps := xdp_redirect.bpf.o xdp_sample.bpf.o

xdp_monitor.skel.h-deps := xdp_monitor.bpf.o xdp_sample.bpf.o



LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.bpf.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))

samples/bpf/xdp_redirect_kern.c→samples/bpf/xdp_redirect.bpf.c

+49 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2016 John Fastabend <john.r.fastabend@intel.com>

 *

 * This program is free software; you can redistribute it and/or
@@ -9,79 +10,37 @@ 
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

 * General Public License for more details.

 */

#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/bpf_helpers.h>

#include "vmlinux.h"

#include "xdp_sample.bpf.h"

#include "xdp_sample_shared.h"



struct {

	__uint(type, BPF_MAP_TYPE_ARRAY);

	__type(key, int);

	__type(value, int);

	__uint(max_entries, 1);

} tx_port SEC(".maps");

const volatile int ifindex_out;



/* Count RX packets, as XDP bpf_prog doesn't get direct TX-success

 * feedback.  Redirect TX errors can be caught via a tracepoint.

 */

struct {

	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);

	__type(key, u32);

	__type(value, long);

	__uint(max_entries, 1);

} rxcnt SEC(".maps");



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];

}



SEC("xdp_redirect")

SEC("xdp")

int xdp_redirect_prog(struct xdp_md *ctx)

{

	void *data_end = (void *)(long)ctx->data_end;

	void *data = (void *)(long)ctx->data;

	u32 key = bpf_get_smp_processor_id();

	struct ethhdr *eth = data;

	int rc = XDP_DROP;

	int *ifindex, port = 0;

	long *value;

	u32 key = 0;

	struct datarec *rec;

	u64 nh_off;



	nh_off = sizeof(*eth);

	if (data + nh_off > data_end)

		return rc;

		return XDP_DROP;



	ifindex = bpf_map_lookup_elem(&tx_port, &port);

	if (!ifindex)

		return rc;



	value = bpf_map_lookup_elem(&rxcnt, &key);

	if (value)

		*value += 1;

	rec = bpf_map_lookup_elem(&rx_cnt, &key);

	if (!rec)

		return XDP_PASS;

	NO_TEAR_INC(rec->processed);



	swap_src_dst_mac(data);

	return bpf_redirect(*ifindex, 0);

	return bpf_redirect(ifindex_out, 0);

}



/* Redirect require an XDP bpf_prog loaded on the TX device */

SEC("xdp_redirect_dummy")

SEC("xdp")

int xdp_redirect_dummy_prog(struct xdp_md *ctx)

{

	return XDP_PASS;