[PATCHv13 bpf-next 4/6] sample/bpf: add xdp_redirect_map_multicast test

Hangbin Liu
2020-12-21T12:36:24Z

This is a sample for xdp multicast. 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>
---

v12: add devmap xdp_prog on egress support
v10-v11: no update
v9: use NULL directly for arg2 and redefine the maps with btf format
v5: add a null_map as we have strict the arg2 to ARG_CONST_MAP_PTR.
Move the testing part to bpf selftest in next patch.
v4: no update.
v3: add rxcnt map to show the packet transmit speed.
v2: no update.

---
samples/bpf/Makefile | 3 +
samples/bpf/xdp_redirect_map_multi_kern.c | 96 +++++++
samples/bpf/xdp_redirect_map_multi_user.c | 301 ++++++++++++++++++++++
3 files changed, 400 insertions(+)
create mode 100644 samples/bpf/xdp_redirect_map_multi_kern.c
create mode 100644 samples/bpf/xdp_redirect_map_multi_user.c

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 26fc96ca619e..200029fcf53c 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -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
diff --git a/samples/bpf/xdp_redirect_map_multi_kern.c b/samples/bpf/xdp_redirect_map_multi_kern.c
new file mode 100644
index 000000000000..0c63aace9bd2
--- /dev/null
+++ b/samples/bpf/xdp_redirect_map_multi_kern.c
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#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 stroe 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_multi(forward_map, NULL, 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";
diff --git a/samples/bpf/xdp_redirect_map_multi_user.c b/samples/bpf/xdp_redirect_map_multi_user.c
new file mode 100644
index 000000000000..67ffc294567c
--- /dev/null
+++ b/samples/bpf/xdp_redirect_map_multi_user.c
@@ -0,0 +1,301 @@
+// 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 = -1;
+ 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_title(obj, "xdp_redirect_general");
+ forward_map_fd = bpf_object__find_map_fd_by_name(obj, "forward_map_general");
+ } else {
+ ingress_prog = bpf_object__find_program_by_title(obj, "xdp_redirect_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_title(obj, "xdp_devmap/map_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;
+}
--
2.26.2