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306da4e685
For supporting XDP_REDIRECT, a device driver must (obviously) implement the "TX" function ndo_xdp_xmit(). An additional requirement is you cannot TX out a device, unless it also have a xdp bpf program attached. This dependency is caused by the driver code need to setup XDP resources before it can ndo_xdp_xmit. Update bpf samples xdp_redirect and xdp_redirect_map to automatically attach a dummy XDP program to the configured ifindex_out device. Use the XDP flag XDP_FLAGS_UPDATE_IF_NOEXIST on the dummy load, to avoid overriding an existing XDP prog on the device. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
145 lines
3.3 KiB
C
145 lines
3.3 KiB
C
/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#include <linux/bpf.h>
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#include <linux/if_link.h>
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#include <assert.h>
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#include <errno.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdbool.h>
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#include <string.h>
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#include <unistd.h>
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#include <libgen.h>
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#include "bpf_load.h"
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#include "bpf_util.h"
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#include "libbpf.h"
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static int ifindex_in;
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static int ifindex_out;
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static bool ifindex_out_xdp_dummy_attached = true;
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static __u32 xdp_flags;
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static void int_exit(int sig)
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{
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set_link_xdp_fd(ifindex_in, -1, xdp_flags);
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if (ifindex_out_xdp_dummy_attached)
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set_link_xdp_fd(ifindex_out, -1, xdp_flags);
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exit(0);
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}
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static void poll_stats(int interval, int ifindex)
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{
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unsigned int nr_cpus = bpf_num_possible_cpus();
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__u64 values[nr_cpus], prev[nr_cpus];
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memset(prev, 0, sizeof(prev));
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while (1) {
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__u64 sum = 0;
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__u32 key = 0;
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int i;
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sleep(interval);
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assert(bpf_map_lookup_elem(map_fd[1], &key, values) == 0);
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for (i = 0; i < nr_cpus; i++)
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sum += (values[i] - prev[i]);
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if (sum)
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printf("ifindex %i: %10llu pkt/s\n",
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ifindex, sum / interval);
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memcpy(prev, values, sizeof(values));
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}
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}
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static void usage(const char *prog)
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{
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fprintf(stderr,
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"usage: %s [OPTS] IFINDEX_IN IFINDEX_OUT\n\n"
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"OPTS:\n"
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" -S use skb-mode\n"
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" -N enforce native mode\n",
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prog);
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}
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int main(int argc, char **argv)
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{
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const char *optstr = "SN";
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char filename[256];
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int ret, opt, key = 0;
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while ((opt = getopt(argc, argv, optstr)) != -1) {
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switch (opt) {
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case 'S':
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xdp_flags |= XDP_FLAGS_SKB_MODE;
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break;
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case 'N':
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xdp_flags |= XDP_FLAGS_DRV_MODE;
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break;
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default:
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usage(basename(argv[0]));
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return 1;
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}
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}
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if (optind == argc) {
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printf("usage: %s IFINDEX_IN IFINDEX_OUT\n", argv[0]);
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return 1;
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}
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ifindex_in = strtoul(argv[optind], NULL, 0);
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ifindex_out = strtoul(argv[optind + 1], NULL, 0);
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printf("input: %d output: %d\n", ifindex_in, ifindex_out);
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snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
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if (load_bpf_file(filename)) {
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printf("%s", bpf_log_buf);
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return 1;
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}
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if (!prog_fd[0]) {
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printf("load_bpf_file: %s\n", strerror(errno));
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return 1;
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}
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if (set_link_xdp_fd(ifindex_in, prog_fd[0], xdp_flags) < 0) {
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printf("ERROR: link set xdp fd failed on %d\n", ifindex_in);
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return 1;
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}
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/* Loading dummy XDP prog on out-device */
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if (set_link_xdp_fd(ifindex_out, prog_fd[1],
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(xdp_flags | XDP_FLAGS_UPDATE_IF_NOEXIST)) < 0) {
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printf("WARN: link set xdp fd failed on %d\n", ifindex_out);
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ifindex_out_xdp_dummy_attached = false;
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}
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signal(SIGINT, int_exit);
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signal(SIGTERM, int_exit);
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printf("map[0] (vports) = %i, map[1] (map) = %i, map[2] (count) = %i\n",
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map_fd[0], map_fd[1], map_fd[2]);
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/* populate virtual to physical port map */
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ret = bpf_map_update_elem(map_fd[0], &key, &ifindex_out, 0);
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if (ret) {
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perror("bpf_update_elem");
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goto out;
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}
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poll_stats(2, ifindex_out);
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out:
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return 0;
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}
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