Thread (23 messages) 23 messages, 1 author, 2021-08-21
STALE1772d LANDED

[PATCH bpf-next v4 19/22] samples: bpf: Convert xdp_redirect_map_kern.o to XDP samples helper

From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: 2021-08-21 00:21:21
Also in: netdev
Subsystem: bpf [general] (safe dynamic programs and tools), the rest, xdp (express data path) · Maintainers: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds, David S. Miller, Jakub Kicinski, Jesper Dangaard Brouer, John Fastabend

Also update it to use consistent SEC("xdp") and SEC("xdp_devmap")
naming, and use global variable instead of BPF map for copying the mac
address.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 samples/bpf/Makefile                          |  6 +-
 ...rect_map_kern.c => xdp_redirect_map.bpf.c} | 89 +++++--------------
 2 files changed, 25 insertions(+), 70 deletions(-)
 rename samples/bpf/{xdp_redirect_map_kern.c => xdp_redirect_map.bpf.c} (57%)
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 43d3e52a8659..8faef4bcead4 100644
--- 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_kern.o
 always-y += xdp_redirect_map_multi_kern.o
 always-y += xdp_rxq_info_kern.o
 always-y += xdp2skb_meta_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.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
 
@@ -368,10 +368,12 @@ $(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.skel.h xdp_monitor.skel.h
+LINKED_SKELS := xdp_redirect_cpu.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.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_kern.c b/samples/bpf/xdp_redirect_map.bpf.c
similarity index 57%
rename from samples/bpf/xdp_redirect_map_kern.c
rename to samples/bpf/xdp_redirect_map.bpf.c
index a92b8e567bdd..59efd656e1b2 100644
--- a/samples/bpf/xdp_redirect_map_kern.c
+++ b/samples/bpf/xdp_redirect_map.bpf.c
@@ -10,14 +10,10 @@
  * 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/if_packet.h>
-#include <linux/if_vlan.h>
-#include <linux/ip.h>
-#include <linux/ipv6.h>
-#include <bpf/bpf_helpers.h>
+
+#include "vmlinux.h"
+#include "xdp_sample.bpf.h"
+#include "xdp_sample_shared.h"
 
 /* The 2nd xdp prog on egress does not support skb mode, so we define two
  * maps, tx_port_general and tx_port_native.
@@ -26,114 +22,71 @@ struct {
 	__uint(type, BPF_MAP_TYPE_DEVMAP);
 	__uint(key_size, sizeof(int));
 	__uint(value_size, sizeof(int));
-	__uint(max_entries, 100);
+	__uint(max_entries, 1);
 } tx_port_general SEC(".maps");
 
 struct {
 	__uint(type, BPF_MAP_TYPE_DEVMAP);
 	__uint(key_size, sizeof(int));
 	__uint(value_size, sizeof(struct bpf_devmap_val));
-	__uint(max_entries, 100);
-} tx_port_native SEC(".maps");
-
-/* Count RX packets, as XDP bpf_prog doesn't get direct TX-success
- * feedback.  Redirect TX errors can be caught via a tracepoint.
- */
-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 interface mac address */
-struct {
-	__uint(type, BPF_MAP_TYPE_ARRAY);
-	__type(key, u32);
-	__type(value, __be64);
 	__uint(max_entries, 1);
-} tx_mac SEC(".maps");
-
-static void swap_src_dst_mac(void *data)
-{
-	unsigned short *p = data;
-	unsigned short dst[3];
+} tx_port_native SEC(".maps");
 
-	dst[0] = p[0];
-	dst[1] = p[1];
-	dst[2] = p[2];
-	p[0] = p[3];
-	p[1] = p[4];
-	p[2] = p[5];
-	p[3] = dst[0];
-	p[4] = dst[1];
-	p[5] = dst[2];
-}
+/* store egress interface mac address */
+const volatile char tx_mac_addr[ETH_ALEN];
 
 static __always_inline int xdp_redirect_map(struct xdp_md *ctx, void *redirect_map)
 {
 	void *data_end = (void *)(long)ctx->data_end;
 	void *data = (void *)(long)ctx->data;
+	u32 key = bpf_get_smp_processor_id();
 	struct ethhdr *eth = data;
-	int rc = XDP_DROP;
-	long *value;
-	u32 key = 0;
+	struct datarec *rec;
 	u64 nh_off;
-	int vport;
 
 	nh_off = sizeof(*eth);
 	if (data + nh_off > data_end)
-		return rc;
-
-	/* constant virtual port */
-	vport = 0;
-
-	/* count packet in global counter */
-	value = bpf_map_lookup_elem(&rxcnt, &key);
-	if (value)
-		*value += 1;
+		return XDP_DROP;
 
+	rec = bpf_map_lookup_elem(&rx_cnt, &key);
+	if (!rec)
+		return XDP_PASS;
+	NO_TEAR_INC(rec->processed);
 	swap_src_dst_mac(data);
-
-	/* send packet out physical port */
-	return bpf_redirect_map(redirect_map, vport, 0);
+	return bpf_redirect_map(redirect_map, 0, 0);
 }
 
-SEC("xdp_redirect_general")
+SEC("xdp")
 int xdp_redirect_map_general(struct xdp_md *ctx)
 {
 	return xdp_redirect_map(ctx, &tx_port_general);
 }
 
-SEC("xdp_redirect_native")
+SEC("xdp")
 int xdp_redirect_map_native(struct xdp_md *ctx)
 {
 	return xdp_redirect_map(ctx, &tx_port_native);
 }
 
-SEC("xdp_devmap/map_prog")
+SEC("xdp_devmap/egress")
 int xdp_redirect_map_egress(struct xdp_md *ctx)
 {
 	void *data_end = (void *)(long)ctx->data_end;
 	void *data = (void *)(long)ctx->data;
 	struct ethhdr *eth = data;
-	__be64 *mac;
-	u32 key = 0;
 	u64 nh_off;
 
 	nh_off = sizeof(*eth);
 	if (data + nh_off > data_end)
 		return XDP_DROP;
 
-	mac = bpf_map_lookup_elem(&tx_mac, &key);
-	if (mac)
-		__builtin_memcpy(eth->h_source, mac, ETH_ALEN);
+	__builtin_memcpy(eth->h_source, (const char *)tx_mac_addr, ETH_ALEN);
 
 	return XDP_PASS;
 }
 
 /* Redirect require an XDP bpf_prog loaded on the TX device */
-SEC("xdp_redirect_dummy")
+SEC("xdp")
 int xdp_redirect_dummy_prog(struct xdp_md *ctx)
 {
 	return XDP_PASS;
-- 
2.33.0
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help