// SPDX-License-Identifier: GPL-2.0
#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 <string.h>
#include <net/if.h>
#include <unistd.h>
#include <libgen.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include "bpf_util.h"
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#define MAX_IFACE_NUM 32
#define MAX_INDEX_NUM 1024
static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
static int ifaces[MAX_IFACE_NUM] = {};
static void int_exit(int sig)
{
__u32 prog_id = 0;
int i;
for (i = 0; ifaces[i] > 0; i++) {
if (bpf_xdp_query_id(ifaces[i], xdp_flags, &prog_id)) {
printf("bpf_xdp_query_id failed\n");
exit(1);
}
if (prog_id)
bpf_xdp_detach(ifaces[i], xdp_flags, NULL);
}
exit(0);
}
static int get_mac_addr(unsigned int ifindex, void *mac_addr)
{
char ifname[IF_NAMESIZE];
struct ifreq ifr;
int fd, ret = -1;
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0)
return ret;
if (!if_indextoname(ifindex, ifname))
goto err_out;
strcpy(ifr.ifr_name, ifname);
if (ioctl(fd, SIOCGIFHWADDR, &ifr) != 0)
goto err_out;
memcpy(mac_addr, ifr.ifr_hwaddr.sa_data, 6 * sizeof(char));
ret = 0;
err_out:
close(fd);
return ret;
}
static void usage(const char *prog)
{
fprintf(stderr,
"usage: %s [OPTS] <IFNAME|IFINDEX> <IFNAME|IFINDEX> ...\n"
"OPTS:\n"
" -S use skb-mode\n"
" -N enforce native mode\n"
" -F force loading prog\n"
" -X load xdp program on egress\n",
prog);
}
int main(int argc, char **argv)
{
int prog_fd, group_all, mac_map;
struct bpf_program *ingress_prog, *egress_prog;
int i, err, ret, opt, egress_prog_fd = 0;
struct bpf_devmap_val devmap_val;
bool attach_egress_prog = false;
unsigned char mac_addr[6];
char ifname[IF_NAMESIZE];
struct bpf_object *obj;
unsigned int ifindex;
char filename[256];
while ((opt = getopt(argc, argv, "SNFX")) != -1) {
switch (opt) {
case 'S':
xdp_flags |= XDP_FLAGS_SKB_MODE;
break;
case 'N':
/* default, set below */
break;
case 'F':
xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
break;
case 'X':
attach_egress_prog = true;
break;
default:
usage(basename(argv[0]));
return 1;
}
}
if (!(xdp_flags & XDP_FLAGS_SKB_MODE)) {
xdp_flags |= XDP_FLAGS_DRV_MODE;
} else if (attach_egress_prog) {
printf("Load xdp program on egress with SKB mode not supported yet\n");
goto err_out;
}
if (optind == argc) {
printf("usage: %s <IFNAME|IFINDEX> <IFNAME|IFINDEX> ...\n", argv[0]);
goto err_out;
}
printf("Get interfaces:");
for (i = 0; i < MAX_IFACE_NUM && argv[optind + i]; i++) {
ifaces[i] = if_nametoindex(argv[optind + i]);
if (!ifaces[i])
ifaces[i] = strtoul(argv[optind + i], NULL, 0);
if (!if_indextoname(ifaces[i], ifname)) {
perror("Invalid interface name or i");
goto err_out;
}
if (ifaces[i] > MAX_INDEX_NUM) {
printf(" interface index too large\n");
goto err_out;
}
printf(" %d", ifaces[i]);
}
printf("\n");
snprintf(filename, sizeof(filename), "%s_kern.bpf.o", argv[0]);
obj = bpf_object__open_file(filename, NULL);
err = libbpf_get_error(obj);
if (err)
goto err_out;
err = bpf_object__load(obj);
if (err)
goto err_out;
prog_fd = bpf_program__fd(bpf_object__next_program(obj, NULL));
if (attach_egress_prog)
group_all = bpf_object__find_map_fd_by_name(obj, "map_egress");
else
group_all = bpf_object__find_map_fd_by_name(obj, "map_all");
mac_map = bpf_object__find_map_fd_by_name(obj, "mac_map");
if (group_all < 0 || mac_map < 0) {
printf("bpf_object__find_map_fd_by_name failed\n");
goto err_out;
}
if (attach_egress_prog) {
/* Find ingress/egress prog for 2nd xdp prog */
ingress_prog = bpf_object__find_program_by_name(obj, "xdp_redirect_map_all_prog");
egress_prog = bpf_object__find_program_by_name(obj, "xdp_devmap_prog");
if (!ingress_prog || !egress_prog) {
printf("finding ingress/egress_prog in obj file failed\n");
goto err_out;
}
prog_fd = bpf_program__fd(ingress_prog);
egress_prog_fd = bpf_program__fd(egress_prog);
if (prog_fd < 0 || egress_prog_fd < 0) {
printf("find egress_prog fd failed\n");
goto err_out;
}
}
signal(SIGINT, int_exit);
signal(SIGTERM, int_exit);
/* Init forward multicast groups and exclude group */
for (i = 0; ifaces[i] > 0; i++) {
ifindex = ifaces[i];
if (attach_egress_prog) {
ret = get_mac_addr(ifindex, mac_addr);
if (ret < 0) {
printf("get interface %d mac failed\n", ifindex);
goto err_out;
}
ret = bpf_map_update_elem(mac_map, &ifindex, mac_addr, 0);
if (ret) {
perror("bpf_update_elem mac_map failed\n");
goto err_out;
}
}
/* Add all the interfaces to group all */
devmap_val.ifindex = ifindex;
devmap_val.bpf_prog.fd = egress_prog_fd;
ret = bpf_map_update_elem(group_all, &ifindex, &devmap_val, 0);
if (ret) {
perror("bpf_map_update_elem");
goto err_out;
}
/* bind prog_fd to each interface */
ret = bpf_xdp_attach(ifindex, prog_fd, xdp_flags, NULL);
if (ret) {
printf("Set xdp fd failed on %d\n", ifindex);
goto err_out;
}
}
/* sleep some time for testing */
sleep(999);
return 0;
err_out:
return 1;
}
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