samples: bpf: Convert xdp_redirect_map_multi_kern.o to XDP samples helper

One of the notable changes is using a BPF_MAP_TYPE_HASH instead of array
map to store mac addresses of devices, as the resizing behavior was
based on max_ifindex, which unecessarily maximized the capacity of map
beyond what was needed.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-22-memxor@gmail.com

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 6decc8f9bcc26350bf3f8dd584f940dbc368d6b3..2b3d9e39c4f32fbf8c566be9ec3c3529b51f7b1a 100644 (file)
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -163,7 +163,6 @@ always-y += tcp_clamp_kern.o
 always-y += tcp_basertt_kern.o
 always-y += tcp_tos_reflect_kern.o
 always-y += tcp_dumpstats_kern.o
-always-y += xdp_redirect_map_multi_kern.o
 always-y += xdp_rxq_info_kern.o
 always-y += xdp2skb_meta_kern.o
 always-y += syscall_tp_kern.o
@@ -357,6 +356,7 @@ endef
 CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG))
 
 $(obj)/xdp_redirect_cpu.bpf.o: $(obj)/xdp_sample.bpf.o
+$(obj)/xdp_redirect_map_multi.bpf.o: $(obj)/xdp_sample.bpf.o
 $(obj)/xdp_redirect_map.bpf.o: $(obj)/xdp_sample.bpf.o
 $(obj)/xdp_redirect.bpf.o: $(obj)/xdp_sample.bpf.o
 $(obj)/xdp_monitor.bpf.o: $(obj)/xdp_sample.bpf.o
@@ -369,11 +369,12 @@ $(obj)/%.bpf.o: $(src)/%.bpf.c $(obj)/vmlinux.h $(src)/xdp_sample.bpf.h $(src)/x
                -I$(srctree)/tools/lib $(CLANG_SYS_INCLUDES) \
                -c $(filter %.bpf.c,$^) -o $@
 
-LINKED_SKELS := xdp_redirect_cpu.skel.h xdp_redirect_map.skel.h \
-                xdp_redirect.skel.h xdp_monitor.skel.h
+LINKED_SKELS := xdp_redirect_cpu.skel.h xdp_redirect_map_multi.skel.h \
+               xdp_redirect_map.skel.h xdp_redirect.skel.h xdp_monitor.skel.h
 clean-files += $(LINKED_SKELS)
 
 xdp_redirect_cpu.skel.h-deps := xdp_redirect_cpu.bpf.o xdp_sample.bpf.o
+xdp_redirect_map_multi.skel.h-deps := xdp_redirect_map_multi.bpf.o xdp_sample.bpf.o
 xdp_redirect_map.skel.h-deps := xdp_redirect_map.bpf.o xdp_sample.bpf.o
 xdp_redirect.skel.h-deps := xdp_redirect.bpf.o xdp_sample.bpf.o
 xdp_monitor.skel.h-deps := xdp_monitor.bpf.o xdp_sample.bpf.o

diff --git a/samples/bpf/xdp_redirect_map_multi.bpf.c b/samples/bpf/xdp_redirect_map_multi.bpf.c
new file mode 100644 (file)
index 0000000..8f59d43
--- /dev/null
+++ b/samples/bpf/xdp_redirect_map_multi.bpf.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+#define KBUILD_MODNAME "foo"
+
+#include "vmlinux.h"
+#include "xdp_sample.bpf.h"
+#include "xdp_sample_shared.h"
+
+enum {
+       BPF_F_BROADCAST         = (1ULL << 3),
+       BPF_F_EXCLUDE_INGRESS   = (1ULL << 4),
+};
+
+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");
+
+/* map to store egress interfaces mac addresses */
+struct {
+       __uint(type, BPF_MAP_TYPE_HASH);
+       __type(key, u32);
+       __type(value, __be64);
+       __uint(max_entries, 32);
+} mac_map SEC(".maps");
+
+static int xdp_redirect_map(struct xdp_md *ctx, void *forward_map)
+{
+       u32 key = bpf_get_smp_processor_id();
+       struct datarec *rec;
+
+       rec = bpf_map_lookup_elem(&rx_cnt, &key);
+       if (!rec)
+               return XDP_PASS;
+       NO_TEAR_INC(rec->processed);
+
+       return bpf_redirect_map(forward_map, 0,
+                               BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS);
+}
+
+SEC("xdp")
+int xdp_redirect_map_general(struct xdp_md *ctx)
+{
+       return xdp_redirect_map(ctx, &forward_map_general);
+}
+
+SEC("xdp")
+int xdp_redirect_map_native(struct xdp_md *ctx)
+{
+       return xdp_redirect_map(ctx, &forward_map_native);
+}
+
+SEC("xdp_devmap/egress")
+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_kern.c b/samples/bpf/xdp_redirect_map_multi_kern.c
deleted file mode 100644 (file)
index 71aa23d..0000000
--- a/samples/bpf/xdp_redirect_map_multi_kern.c
+++ /dev/null
@@ -1,88 +0,0 @@
-// 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";