sample/bpf: Add xdp_redirect_map_multi for redirect_map broadcast test

This is a sample for xdp redirect broadcast. In the sample we could forward
all packets between given interfaces. There is also an option -X that could
enable 2nd xdp_prog on egress interface.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210519090747.1655268-4-liuhangbin@gmail.com
This commit is contained in:
Hangbin Liu 2021-05-19 17:07:46 +08:00 коммит произвёл Daniel Borkmann
Родитель e624d4ed4a
Коммит e48cfe4bbf
3 изменённых файлов: 393 добавлений и 0 удалений

Просмотреть файл

@ -41,6 +41,7 @@ tprogs-y += test_map_in_map
tprogs-y += per_socket_stats_example
tprogs-y += xdp_redirect
tprogs-y += xdp_redirect_map
tprogs-y += xdp_redirect_map_multi
tprogs-y += xdp_redirect_cpu
tprogs-y += xdp_monitor
tprogs-y += xdp_rxq_info
@ -99,6 +100,7 @@ test_map_in_map-objs := test_map_in_map_user.o
per_socket_stats_example-objs := cookie_uid_helper_example.o
xdp_redirect-objs := xdp_redirect_user.o
xdp_redirect_map-objs := xdp_redirect_map_user.o
xdp_redirect_map_multi-objs := xdp_redirect_map_multi_user.o
xdp_redirect_cpu-objs := xdp_redirect_cpu_user.o
xdp_monitor-objs := xdp_monitor_user.o
xdp_rxq_info-objs := xdp_rxq_info_user.o
@ -160,6 +162,7 @@ always-y += tcp_tos_reflect_kern.o
always-y += tcp_dumpstats_kern.o
always-y += xdp_redirect_kern.o
always-y += xdp_redirect_map_kern.o
always-y += xdp_redirect_map_multi_kern.o
always-y += xdp_redirect_cpu_kern.o
always-y += xdp_monitor_kern.o
always-y += xdp_rxq_info_kern.o

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@ -0,0 +1,88 @@
// SPDX-License-Identifier: GPL-2.0
#define KBUILD_MODNAME "foo"
#include <uapi/linux/bpf.h>
#include <linux/in.h>
#include <linux/if_ether.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <bpf/bpf_helpers.h>
struct {
__uint(type, BPF_MAP_TYPE_DEVMAP_HASH);
__uint(key_size, sizeof(int));
__uint(value_size, sizeof(int));
__uint(max_entries, 32);
} forward_map_general SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_DEVMAP_HASH);
__uint(key_size, sizeof(int));
__uint(value_size, sizeof(struct bpf_devmap_val));
__uint(max_entries, 32);
} forward_map_native SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__type(key, u32);
__type(value, long);
__uint(max_entries, 1);
} rxcnt SEC(".maps");
/* map to store egress interfaces mac addresses, set the
* max_entries to 1 and extend it in user sapce prog.
*/
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__type(key, u32);
__type(value, __be64);
__uint(max_entries, 1);
} mac_map SEC(".maps");
static int xdp_redirect_map(struct xdp_md *ctx, void *forward_map)
{
long *value;
u32 key = 0;
/* count packet in global counter */
value = bpf_map_lookup_elem(&rxcnt, &key);
if (value)
*value += 1;
return bpf_redirect_map(forward_map, key,
BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS);
}
SEC("xdp_redirect_general")
int xdp_redirect_map_general(struct xdp_md *ctx)
{
return xdp_redirect_map(ctx, &forward_map_general);
}
SEC("xdp_redirect_native")
int xdp_redirect_map_native(struct xdp_md *ctx)
{
return xdp_redirect_map(ctx, &forward_map_native);
}
SEC("xdp_devmap/map_prog")
int xdp_devmap_prog(struct xdp_md *ctx)
{
void *data_end = (void *)(long)ctx->data_end;
void *data = (void *)(long)ctx->data;
u32 key = ctx->egress_ifindex;
struct ethhdr *eth = data;
__be64 *mac;
u64 nh_off;
nh_off = sizeof(*eth);
if (data + nh_off > data_end)
return XDP_DROP;
mac = bpf_map_lookup_elem(&mac_map, &key);
if (mac)
__builtin_memcpy(eth->h_source, mac, ETH_ALEN);
return XDP_PASS;
}
char _license[] SEC("license") = "GPL";

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@ -0,0 +1,302 @@
// 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/resource.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
static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
static int ifaces[MAX_IFACE_NUM] = {};
static int rxcnt_map_fd;
static void int_exit(int sig)
{
__u32 prog_id = 0;
int i;
for (i = 0; ifaces[i] > 0; i++) {
if (bpf_get_link_xdp_id(ifaces[i], &prog_id, xdp_flags)) {
printf("bpf_get_link_xdp_id failed\n");
exit(1);
}
if (prog_id)
bpf_set_link_xdp_fd(ifaces[i], -1, xdp_flags);
}
exit(0);
}
static void poll_stats(int interval)
{
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("Forwarding %10llu pkt/s\n", sum / interval);
memcpy(prev, values, sizeof(values));
}
}
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 int update_mac_map(struct bpf_object *obj)
{
int i, ret = -1, mac_map_fd;
unsigned char mac_addr[6];
unsigned int ifindex;
mac_map_fd = bpf_object__find_map_fd_by_name(obj, "mac_map");
if (mac_map_fd < 0) {
printf("find mac map fd failed\n");
return ret;
}
for (i = 0; ifaces[i] > 0; i++) {
ifindex = ifaces[i];
ret = get_mac_addr(ifindex, mac_addr);
if (ret < 0) {
printf("get interface %d mac failed\n", ifindex);
return ret;
}
ret = bpf_map_update_elem(mac_map_fd, &ifindex, mac_addr, 0);
if (ret) {
perror("bpf_update_elem mac_map_fd");
return ret;
}
}
return 0;
}
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 i, ret, opt, forward_map_fd, max_ifindex = 0;
struct bpf_program *ingress_prog, *egress_prog;
int ingress_prog_fd, egress_prog_fd = 0;
struct bpf_devmap_val devmap_val;
bool attach_egress_prog = false;
char ifname[IF_NAMESIZE];
struct bpf_map *mac_map;
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");
return 1;
}
if (optind == argc) {
printf("usage: %s <IFNAME|IFINDEX> <IFNAME|IFINDEX> ...\n", argv[0]);
return 1;
}
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");
return 1;
}
/* Find the largest index number */
if (ifaces[i] > max_ifindex)
max_ifindex = ifaces[i];
printf(" %d", ifaces[i]);
}
printf("\n");
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
obj = bpf_object__open(filename);
if (libbpf_get_error(obj)) {
printf("ERROR: opening BPF object file failed\n");
obj = NULL;
goto err_out;
}
/* Reset the map size to max ifindex + 1 */
if (attach_egress_prog) {
mac_map = bpf_object__find_map_by_name(obj, "mac_map");
ret = bpf_map__resize(mac_map, max_ifindex + 1);
if (ret < 0) {
printf("ERROR: reset mac map size failed\n");
goto err_out;
}
}
/* load BPF program */
if (bpf_object__load(obj)) {
printf("ERROR: loading BPF object file failed\n");
goto err_out;
}
if (xdp_flags & XDP_FLAGS_SKB_MODE) {
ingress_prog = bpf_object__find_program_by_name(obj, "xdp_redirect_map_general");
forward_map_fd = bpf_object__find_map_fd_by_name(obj, "forward_map_general");
} else {
ingress_prog = bpf_object__find_program_by_name(obj, "xdp_redirect_map_native");
forward_map_fd = bpf_object__find_map_fd_by_name(obj, "forward_map_native");
}
if (!ingress_prog || forward_map_fd < 0) {
printf("finding ingress_prog/forward_map in obj file failed\n");
goto err_out;
}
ingress_prog_fd = bpf_program__fd(ingress_prog);
if (ingress_prog_fd < 0) {
printf("find ingress_prog fd failed\n");
goto err_out;
}
rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
if (rxcnt_map_fd < 0) {
printf("bpf_object__find_map_fd_by_name failed\n");
goto err_out;
}
if (attach_egress_prog) {
/* Update mac_map with all egress interfaces' mac addr */
if (update_mac_map(obj) < 0) {
printf("Error: update mac map failed");
goto err_out;
}
/* Find egress prog fd */
egress_prog = bpf_object__find_program_by_name(obj, "xdp_devmap_prog");
if (!egress_prog) {
printf("finding egress_prog in obj file failed\n");
goto err_out;
}
egress_prog_fd = bpf_program__fd(egress_prog);
if (egress_prog_fd < 0) {
printf("find egress_prog fd failed\n");
goto err_out;
}
}
/* Remove attached program when program is interrupted or killed */
signal(SIGINT, int_exit);
signal(SIGTERM, int_exit);
/* Init forward multicast groups */
for (i = 0; ifaces[i] > 0; i++) {
ifindex = ifaces[i];
/* bind prog_fd to each interface */
ret = bpf_set_link_xdp_fd(ifindex, ingress_prog_fd, xdp_flags);
if (ret) {
printf("Set xdp fd failed on %d\n", ifindex);
goto err_out;
}
/* Add all the interfaces to forward group and attach
* egress devmap programe if exist
*/
devmap_val.ifindex = ifindex;
devmap_val.bpf_prog.fd = egress_prog_fd;
ret = bpf_map_update_elem(forward_map_fd, &ifindex, &devmap_val, 0);
if (ret) {
perror("bpf_map_update_elem forward_map");
goto err_out;
}
}
poll_stats(2);
return 0;
err_out:
return 1;
}