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/* SPDX-License-Identifier: GPL-2.0 */
static const char *__doc__ = "XDP redirect helper\n"
" - Allows to populate/query tx_port and redirect_params maps\n";
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <getopt.h>
#include <stdbool.h>
#include <locale.h>
#include <unistd.h>
#include <time.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include <net/if.h>
#include <linux/if_ether.h>
#include <linux/if_link.h> /* depend on kernel-headers installed */
#include "common/common_params.h"
#include "common/common_user_bpf_xdp.h"
#include "common/common_libbpf.h"
#include "common/xdp_stats_kern_user.h"
static const struct option_wrapper long_options[] = {
{{"help", no_argument, NULL, 'h' },
"Show help", false},
{{"dev", required_argument, NULL, 'd' },
"Operate on device <ifname>", "<ifname>", true},
{{"redirect-dev", required_argument, NULL, 'r' },
"Redirect to device <ifname>", "<ifname>", true},
{{"src-mac", required_argument, NULL, 'L' },
"Source MAC address of <dev>", "<mac>", true },
{{"dest-mac", required_argument, NULL, 'R' },
"Destination MAC address of <redirect-dev>", "<mac>", true },
{{"quiet", no_argument, NULL, 'q' },
"Quiet mode (no output)"},
{{0, 0, NULL, 0 }, NULL, false}
};
static int parse_u8(char *str, unsigned char *x)
{
unsigned long z;
z = strtoul(str, 0, 16);
if (z > 0xff)
return -1;
if (x)
*x = z;
return 0;
}
static int parse_mac(char *str, unsigned char mac[ETH_ALEN])
{
if (parse_u8(str, &mac[0]) < 0)
return -1;
if (parse_u8(str + 3, &mac[1]) < 0)
return -1;
if (parse_u8(str + 6, &mac[2]) < 0)
return -1;
if (parse_u8(str + 9, &mac[3]) < 0)
return -1;
if (parse_u8(str + 12, &mac[4]) < 0)
return -1;
if (parse_u8(str + 15, &mac[5]) < 0)
return -1;
return 0;
}
static int write_iface_params(int map_fd, unsigned char *src, unsigned char *dest)
{
if (bpf_map_update_elem(map_fd, src, dest, 0) < 0) {
fprintf(stderr,
"WARN: Failed to update bpf map file: err(%d):%s\n",
errno, strerror(errno));
return -1;
}
printf("forward: %02x:%02x:%02x:%02x:%02x:%02x -> %02x:%02x:%02x:%02x:%02x:%02x\n",
src[0], src[1], src[2], src[3], src[4], src[5],
dest[0], dest[1], dest[2], dest[3], dest[4], dest[5]
);
return 0;
}
#ifndef PATH_MAX
#define PATH_MAX 4096
#endif
const char *pin_basedir = "/sys/fs/bpf";
int main(int argc, char **argv)
{
int i;
int len;
int map_fd;
bool redirect_map;
char pin_dir[PATH_MAX];
unsigned char src[ETH_ALEN];
unsigned char dest[ETH_ALEN];
struct config cfg = {
.ifindex = -1,
.redirect_ifindex = -1,
};
/* Cmdline options can change progsec */
parse_cmdline_args(argc, argv, long_options, &cfg, __doc__);
redirect_map = (cfg.ifindex > 0) && (cfg.redirect_ifindex > 0);
if (cfg.redirect_ifindex > 0 && cfg.ifindex == -1) {
fprintf(stderr, "ERR: required option --dev missing\n\n");
usage(argv[0], __doc__, long_options, (argc == 1));
return EXIT_FAIL_OPTION;
}
len = snprintf(pin_dir, PATH_MAX, "%s/%s", pin_basedir, cfg.ifname);
if (len < 0) {
fprintf(stderr, "ERR: creating pin dirname\n");
return EXIT_FAIL_OPTION;
}
if (parse_mac(cfg.src_mac, src) < 0) {
fprintf(stderr, "ERR: can't parse mac address %s\n", cfg.src_mac);
return EXIT_FAIL_OPTION;
}
if (parse_mac(cfg.dest_mac, dest) < 0) {
fprintf(stderr, "ERR: can't parse mac address %s\n", cfg.dest_mac);
return EXIT_FAIL_OPTION;
}
/* Open the tx_port map corresponding to the cfg.ifname interface */
map_fd = open_bpf_map_file(pin_dir, "tx_port", NULL);
if (map_fd < 0) {
return EXIT_FAIL_BPF;
}
printf("map dir: %s\n", pin_dir);
if (redirect_map) {
/* setup a virtual port for the static redirect */
i = 0;
bpf_map_update_elem(map_fd, &i, &cfg.redirect_ifindex, 0);
printf("redirect from ifnum=%d to ifnum=%d\n", cfg.ifindex, cfg.redirect_ifindex);
/* Open the redirect_params map */
map_fd = open_bpf_map_file(pin_dir, "redirect_params", NULL);
if (map_fd < 0) {
return EXIT_FAIL_BPF;
}
/* Setup the mapping containing MAC addresses */
if (write_iface_params(map_fd, src, dest) < 0) {
fprintf(stderr, "can't write iface params\n");
return 1;
}
} else {
/* setup 1-1 mapping for the dynamic router */
for (i = 1; i < 256; ++i)
bpf_map_update_elem(map_fd, &i, &i, 0);
}
return EXIT_OK;
}
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