Merge branch 'bpf-xsk-sh-umem'

Tushar Vyavahare says:

====================
Implement a test for the SHARED_UMEM feature in this patch set and make
necessary changes/improvements. Ensure that the framework now supports
different streams for different sockets.

v2->v3:
- Set the sock_num at the end of the while loop.
- Declare xsk at the top of the while loop.

v1->v2:
- Remove generate_mac_addresses() and generate mac addresses based on
  the number of sockets in __test_spec_init() function. [Magnus]
- Update Makefile to include find_bit.c for compiling xskxceiver.
- Add bitmap_full() function to verify all bits are set to break the
  while loop in the receive_pkts() and send_pkts() functions.
- Replace __test_and_set_bit() function with __set_bit() function.
- Add single return check for wait_for_tx_completion() function call.

Patch series summary:

1: Move the packet stream from the ifobject struct to the xsk_socket_info
   struct to enable the use of different streams for different sockets
   This will facilitate the sending and receiving of data from multiple
   sockets simultaneously using the SHARED_XDP_UMEM feature.

   It gives flexibility of send/recive individual traffic on particular
   socket.

2: Rename the header file to a generic name so that it can be used by all
   future XDP programs.

3: Move the src_mac and dst_mac fields from the ifobject structure to the
   xsk_socket_info structure to achieve per-socket MAC address assignment.
   Require this in order to steer traffic to various sockets in subsequent
   patches.

4: Improve the receive_pkt() function to enable it to receive packets from
   multiple sockets. Define a sock_num variable to iterate through all the
   sockets in the Rx path. Add nb_valid_entries to check that all the
   expected number of packets are received.

5: The pkt_set() function no longer needs the umem parameter. This commit
   removes the umem parameter from the pkt_set() function.

6: Iterate over all the sockets in the send pkts function. Update
   send_pkts() to handle multiple sockets for sending packets. Multiple TX
   sockets are utilized alternately based on the batch size for improve
   packet transmission.

7: Modify xsk_update_xskmap() to accept the index as an argument, enabling
   the addition of multiple sockets to xskmap.

8: Add a new test for testing shared umem feature. This is accomplished by
   adding a new XDP program and using the multiple sockets. The new XDP
   program redirects the packets based on the destination MAC address.
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Author: borkmann

tools/testing/selftests/bpf/Makefile

@@ -641,7 +641,9 @@ $(OUTPUT)/test_verifier: test_verifier.c verifier/tests.h $(BPFOBJ) | $(OUTPUT)
 	$(call msg,BINARY,,$@)
 	$(Q)$(CC) $(CFLAGS) $(filter %.a %.o %.c,$^) $(LDLIBS) -o $@
 
-$(OUTPUT)/xskxceiver: xskxceiver.c xskxceiver.h $(OUTPUT)/xsk.o $(OUTPUT)/xsk_xdp_progs.skel.h $(BPFOBJ) | $(OUTPUT)
+# Include find_bit.c to compile xskxceiver.
+EXTRA_SRC := $(TOOLSDIR)/lib/find_bit.c
+$(OUTPUT)/xskxceiver: $(EXTRA_SRC) xskxceiver.c xskxceiver.h $(OUTPUT)/xsk.o $(OUTPUT)/xsk_xdp_progs.skel.h $(BPFOBJ) | $(OUTPUT)
 	$(call msg,BINARY,,$@)
 	$(Q)$(CC) $(CFLAGS) $(filter %.a %.o %.c,$^) $(LDLIBS) -o $@
 

tools/testing/selftests/bpf/progs/xsk_xdp_progs.c

@@ -3,11 +3,12 @@
 
 #include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>
-#include "xsk_xdp_metadata.h"
+#include <linux/if_ether.h>
+#include "xsk_xdp_common.h"
 
 struct {
 	__uint(type, BPF_MAP_TYPE_XSKMAP);
-	__uint(max_entries, 1);
+	__uint(max_entries, 2);
 	__uint(key_size, sizeof(int));
 	__uint(value_size, sizeof(int));
 } xsk SEC(".maps");
@@ -52,4 +53,21 @@ SEC("xdp.frags") int xsk_xdp_populate_metadata(struct xdp_md *xdp)
 	return bpf_redirect_map(&xsk, 0, XDP_DROP);
 }
 
+SEC("xdp") int xsk_xdp_shared_umem(struct xdp_md *xdp)
+{
+	void *data = (void *)(long)xdp->data;
+	void *data_end = (void *)(long)xdp->data_end;
+	struct ethhdr *eth = data;
+
+	if (eth + 1 > data_end)
+		return XDP_DROP;
+
+	/* Redirecting packets based on the destination MAC address */
+	idx = ((unsigned int)(eth->h_dest[5])) / 2;
+	if (idx > MAX_SOCKETS)
+		return XDP_DROP;
+
+	return bpf_redirect_map(&xsk, idx, XDP_DROP);
+}
+
 char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/xsk.c

@@ -442,10 +442,9 @@ void xsk_clear_xskmap(struct bpf_map *map)
 	bpf_map_delete_elem(map_fd, &index);
 }
 
-int xsk_update_xskmap(struct bpf_map *map, struct xsk_socket *xsk)
+int xsk_update_xskmap(struct bpf_map *map, struct xsk_socket *xsk, u32 index)
 {
 	int map_fd, sock_fd;
-	u32 index = 0;
 
 	map_fd = bpf_map__fd(map);
 	sock_fd = xsk_socket__fd(xsk);

tools/testing/selftests/bpf/xsk.h

@@ -204,7 +204,7 @@ struct xsk_umem_config {
 
 int xsk_attach_xdp_program(struct bpf_program *prog, int ifindex, u32 xdp_flags);
 void xsk_detach_xdp_program(int ifindex, u32 xdp_flags);
-int xsk_update_xskmap(struct bpf_map *map, struct xsk_socket *xsk);
+int xsk_update_xskmap(struct bpf_map *map, struct xsk_socket *xsk, u32 index);
 void xsk_clear_xskmap(struct bpf_map *map);
 bool xsk_is_in_mode(u32 ifindex, int mode);
 

tools/testing/selftests/bpf/xsk_xdp_common.h

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef XSK_XDP_COMMON_H_
+#define XSK_XDP_COMMON_H_
+
+#define MAX_SOCKETS 2
+
+struct xdp_info {
+	__u64 count;
+} __attribute__((aligned(32)));
+
+#endif /* XSK_XDP_COMMON_H_ */