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// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2016 John Fastabend <john.r.fastabend@intel.com>
*/
#include <linux/bpf.h>
#include <linux/if_link.h>
#include <assert.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>
#include <libgen.h>
#include <sys/resource.h>
#include "bpf_util.h"
#include <bpf/bpf.h>
#include "bpf/libbpf.h"
static int ifindex_in;
static int ifindex_out;
static bool ifindex_out_xdp_dummy_attached = true;
static __u32 prog_id;
static __u32 dummy_prog_id;
static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
static int rxcnt_map_fd;
static void int_exit(int sig)
{
__u32 curr_prog_id = 0;
if (bpf_get_link_xdp_id(ifindex_in, &curr_prog_id, xdp_flags)) {
printf("bpf_get_link_xdp_id failed\n");
exit(1);
}
if (prog_id == curr_prog_id)
bpf_set_link_xdp_fd(ifindex_in, -1, xdp_flags);
else if (!curr_prog_id)
printf("couldn't find a prog id on iface IN\n");
else
printf("program on iface IN changed, not removing\n");
if (ifindex_out_xdp_dummy_attached) {
curr_prog_id = 0;
if (bpf_get_link_xdp_id(ifindex_out, &curr_prog_id,
xdp_flags)) {
printf("bpf_get_link_xdp_id failed\n");
exit(1);
}
if (dummy_prog_id == curr_prog_id)
bpf_set_link_xdp_fd(ifindex_out, -1, xdp_flags);
else if (!curr_prog_id)
printf("couldn't find a prog id on iface OUT\n");
else
printf("program on iface OUT changed, not removing\n");
}
exit(0);
}
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(rxcnt_map_fd, &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));
}
}
static void usage(const char *prog)
{
fprintf(stderr,
"usage: %s [OPTS] IFINDEX_IN IFINDEX_OUT\n\n"
"OPTS:\n"
" -S use skb-mode\n"
" -N enforce native mode\n"
" -F force loading prog\n",
prog);
}
int main(int argc, char **argv)
{
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
struct bpf_prog_load_attr prog_load_attr = {
.prog_type = BPF_PROG_TYPE_XDP,
};
struct bpf_program *prog, *dummy_prog;
int prog_fd, tx_port_map_fd, opt;
struct bpf_prog_info info = {};
__u32 info_len = sizeof(info);
const char *optstr = "FSN";
struct bpf_object *obj;
char filename[256];
int dummy_prog_fd;
int ret, key = 0;
while ((opt = getopt(argc, argv, optstr)) != -1) {
switch (opt) {
case 'S':
xdp_flags |= XDP_FLAGS_SKB_MODE;
break;
case 'N':
xdp_flags |= XDP_FLAGS_DRV_MODE;
break;
case 'F':
xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
break;
default:
usage(basename(argv[0]));
return 1;
}
}
if (optind == argc) {
printf("usage: %s IFINDEX_IN IFINDEX_OUT\n", argv[0]);
return 1;
}
if (setrlimit(RLIMIT_MEMLOCK, &r)) {
perror("setrlimit(RLIMIT_MEMLOCK)");
return 1;
}
ifindex_in = strtoul(argv[optind], NULL, 0);
ifindex_out = strtoul(argv[optind + 1], NULL, 0);
printf("input: %d output: %d\n", ifindex_in, ifindex_out);
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
prog_load_attr.file = filename;
if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
return 1;
prog = bpf_program__next(NULL, obj);
dummy_prog = bpf_program__next(prog, obj);
if (!prog || !dummy_prog) {
printf("finding a prog in obj file failed\n");
return 1;
}
/* bpf_prog_load_xattr gives us the pointer to first prog's fd,
* so we're missing only the fd for dummy prog
*/
dummy_prog_fd = bpf_program__fd(dummy_prog);
if (prog_fd < 0 || dummy_prog_fd < 0) {
printf("bpf_prog_load_xattr: %s\n", strerror(errno));
return 1;
}
tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port");
rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
if (tx_port_map_fd < 0 || rxcnt_map_fd < 0) {
printf("bpf_object__find_map_fd_by_name failed\n");
return 1;
}
if (bpf_set_link_xdp_fd(ifindex_in, prog_fd, xdp_flags) < 0) {
printf("ERROR: link set xdp fd failed on %d\n", ifindex_in);
return 1;
}
ret = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
if (ret) {
printf("can't get prog info - %s\n", strerror(errno));
return ret;
}
prog_id = info.id;
/* Loading dummy XDP prog on out-device */
if (bpf_set_link_xdp_fd(ifindex_out, dummy_prog_fd,
(xdp_flags | XDP_FLAGS_UPDATE_IF_NOEXIST)) < 0) {
printf("WARN: link set xdp fd failed on %d\n", ifindex_out);
ifindex_out_xdp_dummy_attached = false;
}
memset(&info, 0, sizeof(info));
ret = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
if (ret) {
printf("can't get prog info - %s\n", strerror(errno));
return ret;
}
dummy_prog_id = info.id;
signal(SIGINT, int_exit);
signal(SIGTERM, int_exit);
/* bpf redirect port */
ret = bpf_map_update_elem(tx_port_map_fd, &key, &ifindex_out, 0);
if (ret) {
perror("bpf_update_elem");
goto out;
}
poll_stats(2, ifindex_out);
out:
return 0;
}
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