From 9d6e005287ee23c7e25b04f4ad007bdbaf4fc438 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Mon, 17 Jul 2017 09:30:25 -0700 Subject: [PATCH] xdp: bpf redirect with map sample program Signed-off-by: John Fastabend Tested-by: Andy Gospodarek Acked-by: Daniel Borkmann Acked-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller --- samples/bpf/Makefile | 4 ++ samples/bpf/xdp_redirect_map_kern.c | 83 +++++++++++++++++++++++ samples/bpf/xdp_redirect_map_user.c | 105 ++++++++++++++++++++++++++++++ tools/testing/selftests/bpf/bpf_helpers.h | 2 + 4 files changed, 194 insertions(+) create mode 100644 samples/bpf/xdp_redirect_map_kern.c create mode 100644 samples/bpf/xdp_redirect_map_user.c diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 97734ce..770d46c 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -38,6 +38,7 @@ hostprogs-y += test_map_in_map hostprogs-y += per_socket_stats_example hostprogs-y += load_sock_ops hostprogs-y += xdp_redirect +hostprogs-y += xdp_redirect_map # Libbpf dependencies LIBBPF := ../../tools/lib/bpf/bpf.o @@ -80,6 +81,7 @@ xdp_tx_iptunnel-objs := bpf_load.o $(LIBBPF) xdp_tx_iptunnel_user.o test_map_in_map-objs := bpf_load.o $(LIBBPF) test_map_in_map_user.o per_socket_stats_example-objs := $(LIBBPF) cookie_uid_helper_example.o xdp_redirect-objs := bpf_load.o $(LIBBPF) xdp_redirect_user.o +xdp_redirect_map-objs := bpf_load.o $(LIBBPF) xdp_redirect_map_user.o # Tell kbuild to always build the programs always := $(hostprogs-y) @@ -122,6 +124,7 @@ always += tcp_cong_kern.o always += tcp_iw_kern.o always += tcp_clamp_kern.o always += xdp_redirect_kern.o +always += xdp_redirect_map_kern.o HOSTCFLAGS += -I$(objtree)/usr/include HOSTCFLAGS += -I$(srctree)/tools/lib/ @@ -159,6 +162,7 @@ HOSTLOADLIBES_lwt_len_hist += -l elf HOSTLOADLIBES_xdp_tx_iptunnel += -lelf HOSTLOADLIBES_test_map_in_map += -lelf HOSTLOADLIBES_xdp_redirect += -lelf +HOSTLOADLIBES_xdp_redirect_map += -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/xdp_redirect_map_kern.c b/samples/bpf/xdp_redirect_map_kern.c new file mode 100644 index 0000000..2faf196 --- /dev/null +++ b/samples/bpf/xdp_redirect_map_kern.c @@ -0,0 +1,83 @@ +/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io + * + * 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. + */ +#define KBUILD_MODNAME "foo" +#include +#include +#include +#include +#include +#include +#include +#include "bpf_helpers.h" + +struct bpf_map_def SEC("maps") tx_port = { + .type = BPF_MAP_TYPE_DEVMAP, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 100, +}; + +struct bpf_map_def SEC("maps") rxcnt = { + .type = BPF_MAP_TYPE_PERCPU_ARRAY, + .key_size = sizeof(u32), + .value_size = sizeof(long), + .max_entries = 1, +}; + + +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_map") +int xdp_redirect_map_prog(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; + int vport, port = 0, m = 0; + long *value; + u32 key = 0; + u64 nh_off; + + nh_off = sizeof(*eth); + if (data + nh_off > data_end) + return rc; + + /* constant virtual port */ + vport = 0; + + /* count packet in global counter */ + value = bpf_map_lookup_elem(&rxcnt, &key); + if (value) + *value += 1; + + swap_src_dst_mac(data); + + /* send packet out physical port */ + return bpf_redirect_map(&tx_port, vport, 0); +} + +char _license[] SEC("license") = "GPL"; diff --git a/samples/bpf/xdp_redirect_map_user.c b/samples/bpf/xdp_redirect_map_user.c new file mode 100644 index 0000000..0b8009a --- /dev/null +++ b/samples/bpf/xdp_redirect_map_user.c @@ -0,0 +1,105 @@ +/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io + * + * 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 +#include +#include +#include +#include +#include +#include +#include + +#include "bpf_load.h" +#include "bpf_util.h" +#include "libbpf.h" + +static int ifindex_in; +static int ifindex_out; + +static void int_exit(int sig) +{ + set_link_xdp_fd(ifindex_in, -1, 0); + exit(0); +} + +/* simple per-protocol drop counter + */ +static void poll_stats(int interval, int ifindex) +{ + unsigned int nr_cpus = bpf_num_possible_cpus(); + __u64 values[nr_cpus], prev[nr_cpus]; + + memset(prev, 0, sizeof(prev)); + + while (1) { + __u64 sum = 0; + __u32 key = 0; + int i; + + sleep(interval); + assert(bpf_map_lookup_elem(map_fd[1], &key, values) == 0); + for (i = 0; i < nr_cpus; i++) + sum += (values[i] - prev[i]); + if (sum) + printf("ifindex %i: %10llu pkt/s\n", + ifindex, sum / interval); + memcpy(prev, values, sizeof(values)); + } +} + +int main(int ac, char **argv) +{ + char filename[256]; + int ret, key = 0; + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + + if (ac != 3) { + printf("usage: %s IFINDEX_IN IFINDEX_OUT\n", argv[0]); + return 1; + } + + ifindex_in = strtoul(argv[1], NULL, 0); + ifindex_out = strtoul(argv[2], 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_in, prog_fd[0], 0) < 0) { + printf("link set xdp fd failed\n"); + return 1; + } + + printf("map[0] (vports) = %i, map[1] (map) = %i, map[2] (count) = %i\n", + map_fd[0], map_fd[1], map_fd[2]); + + /* populate virtual to physical port map */ + ret = bpf_map_update_elem(map_fd[0], &key, &ifindex_out, 0); + if (ret) { + perror("bpf_update_elem"); + goto out; + } + + poll_stats(2, ifindex_out); + +out: + return 0; +} diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index d50ac34..acbd605 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -38,6 +38,8 @@ static int (*bpf_clone_redirect)(void *ctx, int ifindex, int flags) = (void *) BPF_FUNC_clone_redirect; static int (*bpf_redirect)(int ifindex, int flags) = (void *) BPF_FUNC_redirect; +static int (*bpf_redirect_map)(void *map, int key, int flags) = + (void *) BPF_FUNC_redirect_map; static int (*bpf_perf_event_output)(void *ctx, void *map, unsigned long long flags, void *data, int size) = -- 2.7.4