selftests/xsk: get rid of built-in XDP program

Get rid of the built-in XDP program that was part of the old libbpf
code in xsk.c and replace it with an eBPF program build using the
framework by all the other bpf selftests. This will form the base for
adding more programs in later commits.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-12-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/Makefile

@@ -240,7 +240,6 @@ $(OUTPUT)/flow_dissector_load: $(TESTING_HELPERS)
 $(OUTPUT)/test_maps: $(TESTING_HELPERS)
 $(OUTPUT)/test_verifier: $(TESTING_HELPERS) $(CAP_HELPERS)
 $(OUTPUT)/xsk.o: $(BPFOBJ)
-$(OUTPUT)/xskxceiver: $(OUTPUT)/xsk.o
 
 BPFTOOL ?= $(DEFAULT_BPFTOOL)
 $(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile)    \
@@ -383,6 +382,7 @@ linked_maps.skel.h-deps := linked_maps1.bpf.o linked_maps2.bpf.o
 test_subskeleton.skel.h-deps := test_subskeleton_lib2.bpf.o test_subskeleton_lib.bpf.o test_subskeleton.bpf.o
 test_subskeleton_lib.skel.h-deps := test_subskeleton_lib2.bpf.o test_subskeleton_lib.bpf.o
 test_usdt.skel.h-deps := test_usdt.bpf.o test_usdt_multispec.bpf.o
+xsk_xdp_progs.skel.h-deps := xsk_xdp_progs.bpf.o
 
 LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))
 
@@ -576,6 +576,10 @@ $(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 $(OUTPUT)/xsk.o $(OUTPUT)/xsk_xdp_progs.skel.h $(BPFOBJ) | $(OUTPUT)
+	$(call msg,BINARY,,$@)
+	$(Q)$(CC) $(CFLAGS) $(filter %.a %.o %.c,$^) $(LDLIBS) -o $@
+
 # Make sure we are able to include and link libbpf against c++.
 $(OUTPUT)/test_cpp: test_cpp.cpp $(OUTPUT)/test_core_extern.skel.h $(BPFOBJ)
 	$(call msg,CXX,,$@)

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

+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Intel */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_XSKMAP);
+	__uint(max_entries, 1);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(int));
+} xsk SEC(".maps");
+
+SEC("xdp") int xsk_def_prog(struct xdp_md *xdp)
+{
+	return bpf_redirect_map(&xsk, 0, XDP_DROP);
+}
+
+char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/xsk.c

@@ -267,87 +267,37 @@ int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area,
 	return err;
 }
 
-static int __xsk_load_xdp_prog(int xsk_map_fd)
+int xsk_attach_xdp_program(struct bpf_program *prog, int ifindex, u32 xdp_flags)
 {
-	static const int log_buf_size = 16 * 1024;
-	char log_buf[log_buf_size];
 	int prog_fd;
 
-	/* This is the post-5.3 kernel C-program:
-	 * SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx)
-	 * {
-	 *     return bpf_redirect_map(&xsks_map, ctx->rx_queue_index, XDP_PASS);
-	 * }
-	 */
-	struct bpf_insn prog[] = {
-		/* r2 = *(u32 *)(r1 + 16) */
-		BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 16),
-		/* r1 = xskmap[] */
-		BPF_LD_MAP_FD(BPF_REG_1, xsk_map_fd),
-		/* r3 = XDP_PASS */
-		BPF_MOV64_IMM(BPF_REG_3, 2),
-		/* call bpf_redirect_map */
-		BPF_EMIT_CALL(BPF_FUNC_redirect_map),
-		BPF_EXIT_INSN(),
-	};
-	size_t insns_cnt = ARRAY_SIZE(prog);
-	LIBBPF_OPTS(bpf_prog_load_opts, opts,
-		.log_buf = log_buf,
-		.log_size = log_buf_size,
-	);
-
-	prog_fd = bpf_prog_load(BPF_PROG_TYPE_XDP, NULL, "LGPL-2.1 or BSD-2-Clause",
-				prog, insns_cnt, &opts);
-	if (prog_fd < 0)
-		pr_warn("BPF log buffer:\n%s", log_buf);
-
-	return prog_fd;
+	prog_fd = bpf_program__fd(prog);
+	return bpf_xdp_attach(ifindex, prog_fd, xdp_flags, NULL);
 }
 
-int xsk_attach_xdp_program(int ifindex, int prog_fd, u32 xdp_flags)
+void xsk_detach_xdp_program(int ifindex, u32 xdp_flags)
 {
-	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts);
-	__u32 prog_id = 0;
-	int link_fd;
-	int err;
-
-	err = bpf_xdp_query_id(ifindex, xdp_flags, &prog_id);
-	if (err) {
-		pr_warn("getting XDP prog id failed\n");
-		return err;
-	}
-
-	/* If there's a netlink-based XDP prog loaded on interface, bail out
-	 * and ask user to do the removal by himself
-	 */
-	if (prog_id) {
-		pr_warn("Netlink-based XDP prog detected, please unload it in order to launch AF_XDP prog\n");
-		return -EINVAL;
-	}
-
-	opts.flags = xdp_flags & ~(XDP_FLAGS_UPDATE_IF_NOEXIST | XDP_FLAGS_REPLACE);
+	bpf_xdp_detach(ifindex, xdp_flags, NULL);
+}
 
-	link_fd = bpf_link_create(prog_fd, ifindex, BPF_XDP, &opts);
-	if (link_fd < 0)
-		pr_warn("bpf_link_create failed: %s\n", strerror(errno));
+void xsk_clear_xskmap(struct bpf_map *map)
+{
+	u32 index = 0;
+	int map_fd;
 
-	return link_fd;
+	map_fd = bpf_map__fd(map);
+	bpf_map_delete_elem(map_fd, &index);
 }
 
-int xsk_load_xdp_program(int *xsk_map_fd, int *prog_fd)
+int xsk_update_xskmap(struct bpf_map *map, struct xsk_socket *xsk)
 {
-	*xsk_map_fd = bpf_map_create(BPF_MAP_TYPE_XSKMAP, "xsks_map", sizeof(int), sizeof(int),
-				     XSKMAP_SIZE, NULL);
-	if (*xsk_map_fd < 0)
-		return *xsk_map_fd;
-
-	*prog_fd = __xsk_load_xdp_prog(*xsk_map_fd);
-	if (*prog_fd < 0) {
-		close(*xsk_map_fd);
-		return *prog_fd;
-	}
+	int map_fd, sock_fd;
+	u32 index = 0;
 
-	return 0;
+	map_fd = bpf_map__fd(map);
+	sock_fd = xsk_socket__fd(xsk);
+
+	return bpf_map_update_elem(map_fd, &index, &sock_fd, 0);
 }
 
 static struct xsk_ctx *xsk_get_ctx(struct xsk_umem *umem, int ifindex,

tools/testing/selftests/bpf/xsk.h

@@ -197,8 +197,10 @@ struct xsk_umem_config {
 	__u32 flags;
 };
 
-int xsk_load_xdp_program(int *xsk_map_fd, int *prog_fd);
-int xsk_attach_xdp_program(int ifindex, int prog_fd, u32 xdp_flags);
+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);
+void xsk_clear_xskmap(struct bpf_map *map);
 
 struct xsk_socket_config {
 	__u32 rx_size;

tools/testing/selftests/bpf/xskxceiver.c

@@ -1207,7 +1207,7 @@ static void thread_common_ops_tx(struct test_spec *test, struct ifobject *ifobje
 {
 	xsk_configure_socket(test, ifobject, test->ifobj_rx->umem, true);
 	ifobject->xsk = &ifobject->xsk_arr[0];
-	ifobject->xsk_map_fd = test->ifobj_rx->xsk_map_fd;
+	ifobject->xskmap = test->ifobj_rx->xskmap;
 	memcpy(ifobject->umem, test->ifobj_rx->umem, sizeof(struct xsk_umem_info));
 }
 
@@ -1247,9 +1247,8 @@ static void thread_common_ops(struct test_spec *test, struct ifobject *ifobject)
 	u64 umem_sz = ifobject->umem->num_frames * ifobject->umem->frame_size;
 	int mmap_flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE;
 	LIBBPF_OPTS(bpf_xdp_query_opts, opts);
-	u32 queue_id = 0;
-	int ret, fd;
 	void *bufs;
+	int ret;
 
 	if (ifobject->umem->unaligned_mode)
 		mmap_flags |= MAP_HUGETLB;
@@ -1274,8 +1273,7 @@ static void thread_common_ops(struct test_spec *test, struct ifobject *ifobject)
 	if (!ifobject->rx_on)
 		return;
 
-	fd = xsk_socket__fd(ifobject->xsk->xsk);
-	ret = bpf_map_update_elem(ifobject->xsk_map_fd, &queue_id, &fd, 0);
+	ret = xsk_update_xskmap(ifobject->xskmap, ifobject->xsk->xsk);
 	if (ret)
 		exit_with_error(errno);
 }
@@ -1309,18 +1307,17 @@ static void *worker_testapp_validate_rx(void *arg)
 {
 	struct test_spec *test = (struct test_spec *)arg;
 	struct ifobject *ifobject = test->ifobj_rx;
-	int id = 0, err, fd = xsk_socket__fd(ifobject->xsk->xsk);
 	struct pollfd fds = { };
-	u32 queue_id = 0;
+	int err;
 
 	if (test->current_step == 1) {
 		thread_common_ops(test, ifobject);
 	} else {
-		bpf_map_delete_elem(ifobject->xsk_map_fd, &id);
-		err = bpf_map_update_elem(ifobject->xsk_map_fd, &queue_id, &fd, 0);
+		xsk_clear_xskmap(ifobject->xskmap);
+		err = xsk_update_xskmap(ifobject->xskmap, ifobject->xsk->xsk);
 		if (err) {
-			printf("Error: Failed to update xskmap, error %s\n", strerror(err));
-			exit_with_error(err);
+			printf("Error: Failed to update xskmap, error %s\n", strerror(-err));
+			exit_with_error(-err);
 		}
 	}
 
@@ -1390,10 +1387,8 @@ static int testapp_validate_traffic_single_thread(struct test_spec *test, struct
 	pthread_join(t0, NULL);
 
 	if (test->total_steps == test->current_step || test->fail) {
-		u32 queue_id = 0;
-
 		xsk_socket__delete(ifobj->xsk->xsk);
-		bpf_map_delete_elem(ifobj->xsk_map_fd, &queue_id);
+		xsk_clear_xskmap(ifobj->xskmap);
 		testapp_clean_xsk_umem(ifobj);
 	}
 
@@ -1482,14 +1477,14 @@ static void testapp_bidi(struct test_spec *test)
 
 static void swap_xsk_resources(struct ifobject *ifobj_tx, struct ifobject *ifobj_rx)
 {
-	int ret, queue_id = 0, fd = xsk_socket__fd(ifobj_rx->xsk->xsk);
+	int ret;
 
 	xsk_socket__delete(ifobj_tx->xsk->xsk);
 	xsk_socket__delete(ifobj_rx->xsk->xsk);
 	ifobj_tx->xsk = &ifobj_tx->xsk_arr[1];
 	ifobj_rx->xsk = &ifobj_rx->xsk_arr[1];
 
-	ret = bpf_map_update_elem(ifobj_rx->xsk_map_fd, &queue_id, &fd, 0);
+	ret = xsk_update_xskmap(ifobj_rx->xskmap, ifobj_rx->xsk->xsk);
 	if (ret)
 		exit_with_error(errno);
 }
@@ -1651,12 +1646,26 @@ static void testapp_invalid_desc(struct test_spec *test)
 	pkt_stream_restore_default(test);
 }
 
+static int xsk_load_xdp_programs(struct ifobject *ifobj)
+{
+	ifobj->xdp_progs = xsk_xdp_progs__open_and_load();
+	if (libbpf_get_error(ifobj->xdp_progs))
+		return libbpf_get_error(ifobj->xdp_progs);
+
+	return 0;
+}
+
+static void xsk_unload_xdp_programs(struct ifobject *ifobj)
+{
+	xsk_xdp_progs__destroy(ifobj->xdp_progs);
+}
+
 static void init_iface(struct ifobject *ifobj, const char *dst_mac, const char *src_mac,
 		       const char *dst_ip, const char *src_ip, const u16 dst_port,
 		       const u16 src_port, thread_func_t func_ptr, bool load_xdp)
 {
-	int xsk_map_fd, prog_fd, err;
 	struct in_addr ip;
+	int err;
 
 	memcpy(ifobj->dst_mac, dst_mac, ETH_ALEN);
 	memcpy(ifobj->src_mac, src_mac, ETH_ALEN);
@@ -1675,20 +1684,20 @@ static void init_iface(struct ifobject *ifobj, const char *dst_mac, const char *
 	if (!load_xdp)
 		return;
 
-	err = xsk_load_xdp_program(&xsk_map_fd, &prog_fd);
+	err = xsk_load_xdp_programs(ifobj);
 	if (err) {
 		printf("Error loading XDP program\n");
 		exit_with_error(err);
 	}
 
-	ifobj->xsk_map_fd = xsk_map_fd;
-	ifobj->prog_fd = prog_fd;
 	ifobj->xdp_flags = mode_to_xdp_flags(TEST_MODE_SKB);
-	ifobj->link_fd = xsk_attach_xdp_program(ifobj->ifindex, prog_fd, ifobj->xdp_flags);
-	if (ifobj->link_fd < 0) {
+	err = xsk_attach_xdp_program(ifobj->xdp_progs->progs.xsk_def_prog, ifobj->ifindex,
+				     ifobj->xdp_flags);
+	if (err) {
 		printf("Error attaching XDP program\n");
-		exit_with_error(ifobj->link_fd);
+		exit_with_error(-err);
 	}
+	ifobj->xskmap = ifobj->xdp_progs->maps.xsk;
 }
 
 static void run_pkt_test(struct test_spec *test, enum test_mode mode, enum test_type type)
@@ -1823,9 +1832,6 @@ static struct ifobject *ifobject_create(void)
 
 static void ifobject_delete(struct ifobject *ifobj)
 {
-	close(ifobj->prog_fd);
-	close(ifobj->xsk_map_fd);
-
 	free(ifobj->umem);
 	free(ifobj->xsk_arr);
 	free(ifobj);
@@ -1864,13 +1870,15 @@ static void change_to_drv_mode(struct ifobject *ifobj)
 	LIBBPF_OPTS(bpf_xdp_query_opts, opts);
 	int ret;
 
-	close(ifobj->link_fd);
-	ifobj->link_fd = xsk_attach_xdp_program(ifobj->ifindex, ifobj->prog_fd,
-						XDP_FLAGS_DRV_MODE);
-	if (ifobj->link_fd < 0) {
+	xsk_detach_xdp_program(ifobj->ifindex, ifobj->xdp_flags);
+	ifobj->xdp_flags = XDP_FLAGS_DRV_MODE;
+	ret = xsk_attach_xdp_program(ifobj->xdp_progs->progs.xsk_def_prog, ifobj->ifindex,
+				     ifobj->xdp_flags);
+	if (ret) {
 		ksft_print_msg("Error attaching XDP program\n");
-		exit_with_error(-ifobj->link_fd);
+		exit_with_error(-ret);
 	}
+	ifobj->xskmap = ifobj->xdp_progs->maps.xsk;
 
 	ret = bpf_xdp_query(ifobj->ifindex, XDP_FLAGS_DRV_MODE, &opts);
 	if (ret)
@@ -1955,6 +1963,8 @@ int main(int argc, char **argv)
 
 	pkt_stream_delete(tx_pkt_stream_default);
 	pkt_stream_delete(rx_pkt_stream_default);
+	xsk_unload_xdp_programs(ifobj_tx);
+	xsk_unload_xdp_programs(ifobj_rx);
 	ifobject_delete(ifobj_tx);
 	ifobject_delete(ifobj_rx);
 

tools/testing/selftests/bpf/xskxceiver.h

@@ -5,6 +5,8 @@
 #ifndef XSKXCEIVER_H_
 #define XSKXCEIVER_H_
 
+#include "xsk_xdp_progs.skel.h"
+
 #ifndef SOL_XDP
 #define SOL_XDP 283
 #endif
@@ -138,9 +140,8 @@ struct ifobject {
 	thread_func_t func_ptr;
 	validation_func_t validation_func;
 	struct pkt_stream *pkt_stream;
-	int xsk_map_fd;
-	int prog_fd;
-	int link_fd;
+	struct xsk_xdp_progs *xdp_progs;
+	struct bpf_map *xskmap;
 	int ifindex;
 	u32 dst_ip;
 	u32 src_ip;