This is a sample for xdp multicast. In the sample we could forward all
packets between given interfaces.
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.
Signed-off-by: Hangbin Liu <liuhang...@gmail.com>
---
samples/bpf/Makefile | 3 +
samples/bpf/xdp_redirect_map_multi_kern.c | 57 ++++++++
samples/bpf/xdp_redirect_map_multi_user.c | 166 ++++++++++++++++++++++
3 files changed, 226 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 8403e4762306..000709bb89c3 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
@@ -97,6 +98,7 @@ test_map_in_map-objs := bpf_load.o 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 := bpf_load.o xdp_redirect_cpu_user.o
xdp_monitor-objs := bpf_load.o xdp_monitor_user.o
xdp_rxq_info-objs := xdp_rxq_info_user.o
@@ -156,6 +158,7 @@ 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..cc7ebaedf55a
--- /dev/null
+++ b/samples/bpf/xdp_redirect_map_multi_kern.c
@@ -0,0 +1,57 @@
+/* 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 <bpf/bpf_helpers.h>
+
+struct bpf_map_def SEC("maps") forward_map = {
+ .type = BPF_MAP_TYPE_DEVMAP_HASH,
+ .key_size = sizeof(u32),
+ .value_size = sizeof(int),
+ .max_entries = 256,
+};
+
+struct bpf_map_def SEC("maps") null_map = {
+ .type = BPF_MAP_TYPE_DEVMAP_HASH,
+ .key_size = sizeof(u32),
+ .value_size = sizeof(int),
+ .max_entries = 1,
+};
+
+struct bpf_map_def SEC("maps") rxcnt = {
+ .type = BPF_MAP_TYPE_PERCPU_ARRAY,
+ .key_size = sizeof(u32),
+ .value_size = sizeof(long),
+ .max_entries = 1,
+};
+
+SEC("xdp_redirect_map_multi")
+int xdp_redirect_map_multi_prog(struct xdp_md *ctx)
+{
+ 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_map,
+ BPF_F_EXCLUDE_INGRESS);
+}
+
+SEC("xdp_dummy")
+int xdp_pass(struct xdp_md *ctx)
+{
+ 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..49f44c91b672
--- /dev/null
+++ b/samples/bpf/xdp_redirect_map_multi_user.c
@@ -0,0 +1,166 @@
+// 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 "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;
+
+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, &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 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",
+ prog);
+}
+
+int main(int argc, char **argv)
+{
+ struct bpf_prog_load_attr prog_load_attr = {
+ .prog_type = BPF_PROG_TYPE_XDP,
+ };
+ int prog_fd, forward_map;
+ int i, ret, opt, ifindex;
+ char ifname[IF_NAMESIZE];
+ struct bpf_object *obj;
+ char filename[256];
+
+ while ((opt = getopt(argc, argv, "SNF")) != -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;
+ default:
+ usage(basename(argv[0]));
+ return 1;
+ }
+ }
+
+ if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+ xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+ 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;
+ }
+ printf(" %d", ifaces[i]);
+ }
+ printf("\n");
+
+ 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;
+
+ forward_map = bpf_object__find_map_fd_by_name(obj, "forward_map");
+ rxcnt = bpf_object__find_map_fd_by_name(obj, "rxcnt");
+
+ if (forward_map < 0 || rxcnt < 0) {
+ printf("bpf_object__find_map_fd_by_name failed\n");
+ return 1;
+ }
+
+ 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];
+
+ /* Add all the interfaces to group all */
+ ret = bpf_map_update_elem(forward_map, &ifindex, &ifindex, 0);
+ if (ret) {
+ perror("bpf_map_update_elem");
+ goto err_out;
+ }
+
+ /* bind prog_fd to each interface */
+ ret = bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags);
+ if (ret) {
+ printf("Set xdp fd failed on %d\n", ifindex);
+ goto err_out;
+ }
+
+ }
+
+ poll_stats(2);
+
+ return 0;
+
+err_out:
+ return 1;
+}
--
2.25.4
