selftests/bpf: add test cases for queue and stack maps

test_maps:
Tests that queue/stack maps are behaving correctly even in corner cases

test_progs:
Tests new ebpf helpers
Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/lib/bpf/bpf.c

@@ -278,6 +278,18 @@ int bpf_map_lookup_elem(int fd, const void *key, void *value)
 	return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
 }
 
+int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value)
+{
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.map_fd = fd;
+	attr.key = ptr_to_u64(key);
+	attr.value = ptr_to_u64(value);
+
+	return sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr));
+}
+
 int bpf_map_delete_elem(int fd, const void *key)
 {
 	union bpf_attr attr;

tools/lib/bpf/bpf.h

@@ -99,6 +99,8 @@ LIBBPF_API int bpf_map_update_elem(int fd, const void *key, const void *value,
 				   __u64 flags);
 
 LIBBPF_API int bpf_map_lookup_elem(int fd, const void *key, void *value);
+LIBBPF_API int bpf_map_lookup_and_delete_elem(int fd, const void *key,
+					      void *value);
 LIBBPF_API int bpf_map_delete_elem(int fd, const void *key);
 LIBBPF_API int bpf_map_get_next_key(int fd, const void *key, void *next_key);
 LIBBPF_API int bpf_obj_pin(int fd, const char *pathname);

tools/testing/selftests/bpf/Makefile

@@ -37,7 +37,7 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test
 	test_lwt_seg6local.o sendmsg4_prog.o sendmsg6_prog.o test_lirc_mode2_kern.o \
 	get_cgroup_id_kern.o socket_cookie_prog.o test_select_reuseport_kern.o \
 	test_skb_cgroup_id_kern.o bpf_flow.o netcnt_prog.o \
-	test_sk_lookup_kern.o test_xdp_vlan.o
+	test_sk_lookup_kern.o test_xdp_vlan.o test_queue_map.o test_stack_map.o
 
 # Order correspond to 'make run_tests' order
 TEST_PROGS := test_kmod.sh \
@@ -118,6 +118,9 @@ CLANG_FLAGS = -I. -I./include/uapi -I../../../include/uapi \
 $(OUTPUT)/test_l4lb_noinline.o: CLANG_FLAGS += -fno-inline
 $(OUTPUT)/test_xdp_noinline.o: CLANG_FLAGS += -fno-inline
 
+$(OUTPUT)/test_queue_map.o: test_queue_stack_map.h
+$(OUTPUT)/test_stack_map.o: test_queue_stack_map.h
+
 BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris)
 BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF)
 BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --help 2>&1 | grep -i 'usage.*llvm')

tools/testing/selftests/bpf/bpf_helpers.h

@@ -16,6 +16,13 @@ static int (*bpf_map_update_elem)(void *map, void *key, void *value,
 	(void *) BPF_FUNC_map_update_elem;
 static int (*bpf_map_delete_elem)(void *map, void *key) =
 	(void *) BPF_FUNC_map_delete_elem;
+static int (*bpf_map_push_elem)(void *map, void *value,
+				unsigned long long flags) =
+	(void *) BPF_FUNC_map_push_elem;
+static int (*bpf_map_pop_elem)(void *map, void *value) =
+	(void *) BPF_FUNC_map_pop_elem;
+static int (*bpf_map_peek_elem)(void *map, void *value) =
+	(void *) BPF_FUNC_map_peek_elem;
 static int (*bpf_probe_read)(void *dst, int size, void *unsafe_ptr) =
 	(void *) BPF_FUNC_probe_read;
 static unsigned long long (*bpf_ktime_get_ns)(void) =

tools/testing/selftests/bpf/test_maps.c

@@ -15,6 +15,7 @@
 #include <string.h>
 #include <assert.h>
 #include <stdlib.h>
+#include <time.h>
 
 #include <sys/wait.h>
 #include <sys/socket.h>
@@ -471,6 +472,122 @@ static void test_devmap(int task, void *data)
 	close(fd);
 }
 
+static void test_queuemap(int task, void *data)
+{
+	const int MAP_SIZE = 32;
+	__u32 vals[MAP_SIZE + MAP_SIZE/2], val;
+	int fd, i;
+
+	/* Fill test values to be used */
+	for (i = 0; i < MAP_SIZE + MAP_SIZE/2; i++)
+		vals[i] = rand();
+
+	/* Invalid key size */
+	fd = bpf_create_map(BPF_MAP_TYPE_QUEUE, 4, sizeof(val), MAP_SIZE,
+			    map_flags);
+	assert(fd < 0 && errno == EINVAL);
+
+	fd = bpf_create_map(BPF_MAP_TYPE_QUEUE, 0, sizeof(val), MAP_SIZE,
+			    map_flags);
+	/* Queue map does not support BPF_F_NO_PREALLOC */
+	if (map_flags & BPF_F_NO_PREALLOC) {
+		assert(fd < 0 && errno == EINVAL);
+		return;
+	}
+	if (fd < 0) {
+		printf("Failed to create queuemap '%s'!\n", strerror(errno));
+		exit(1);
+	}
+
+	/* Push MAP_SIZE elements */
+	for (i = 0; i < MAP_SIZE; i++)
+		assert(bpf_map_update_elem(fd, NULL, &vals[i], 0) == 0);
+
+	/* Check that element cannot be pushed due to max_entries limit */
+	assert(bpf_map_update_elem(fd, NULL, &val, 0) == -1 &&
+	       errno == E2BIG);
+
+	/* Peek element */
+	assert(bpf_map_lookup_elem(fd, NULL, &val) == 0 && val == vals[0]);
+
+	/* Replace half elements */
+	for (i = MAP_SIZE; i < MAP_SIZE + MAP_SIZE/2; i++)
+		assert(bpf_map_update_elem(fd, NULL, &vals[i], BPF_EXIST) == 0);
+
+	/* Pop all elements */
+	for (i = MAP_SIZE/2; i < MAP_SIZE + MAP_SIZE/2; i++)
+		assert(bpf_map_lookup_and_delete_elem(fd, NULL, &val) == 0 &&
+		       val == vals[i]);
+
+	/* Check that there are not elements left */
+	assert(bpf_map_lookup_and_delete_elem(fd, NULL, &val) == -1 &&
+	       errno == ENOENT);
+
+	/* Check that non supported functions set errno to EINVAL */
+	assert(bpf_map_delete_elem(fd, NULL) == -1 && errno == EINVAL);
+	assert(bpf_map_get_next_key(fd, NULL, NULL) == -1 && errno == EINVAL);
+
+	close(fd);
+}
+
+static void test_stackmap(int task, void *data)
+{
+	const int MAP_SIZE = 32;
+	__u32 vals[MAP_SIZE + MAP_SIZE/2], val;
+	int fd, i;
+
+	/* Fill test values to be used */
+	for (i = 0; i < MAP_SIZE + MAP_SIZE/2; i++)
+		vals[i] = rand();
+
+	/* Invalid key size */
+	fd = bpf_create_map(BPF_MAP_TYPE_STACK, 4, sizeof(val), MAP_SIZE,
+			    map_flags);
+	assert(fd < 0 && errno == EINVAL);
+
+	fd = bpf_create_map(BPF_MAP_TYPE_STACK, 0, sizeof(val), MAP_SIZE,
+			    map_flags);
+	/* Stack map does not support BPF_F_NO_PREALLOC */
+	if (map_flags & BPF_F_NO_PREALLOC) {
+		assert(fd < 0 && errno == EINVAL);
+		return;
+	}
+	if (fd < 0) {
+		printf("Failed to create stackmap '%s'!\n", strerror(errno));
+		exit(1);
+	}
+
+	/* Push MAP_SIZE elements */
+	for (i = 0; i < MAP_SIZE; i++)
+		assert(bpf_map_update_elem(fd, NULL, &vals[i], 0) == 0);
+
+	/* Check that element cannot be pushed due to max_entries limit */
+	assert(bpf_map_update_elem(fd, NULL, &val, 0) == -1 &&
+	       errno == E2BIG);
+
+	/* Peek element */
+	assert(bpf_map_lookup_elem(fd, NULL, &val) == 0 && val == vals[i - 1]);
+
+	/* Replace half elements */
+	for (i = MAP_SIZE; i < MAP_SIZE + MAP_SIZE/2; i++)
+		assert(bpf_map_update_elem(fd, NULL, &vals[i], BPF_EXIST) == 0);
+
+	/* Pop all elements */
+	for (i = MAP_SIZE + MAP_SIZE/2 - 1; i >= MAP_SIZE/2; i--)
+		assert(bpf_map_lookup_and_delete_elem(fd, NULL, &val) == 0 &&
+		       val == vals[i]);
+
+	/* Check that there are not elements left */
+	assert(bpf_map_lookup_and_delete_elem(fd, NULL, &val) == -1 &&
+	       errno == ENOENT);
+
+	/* Check that non supported functions set errno to EINVAL */
+	assert(bpf_map_delete_elem(fd, NULL) == -1 && errno == EINVAL);
+	assert(bpf_map_get_next_key(fd, NULL, NULL) == -1 && errno == EINVAL);
+
+	close(fd);
+}
+
 #include <sys/socket.h>
 #include <sys/ioctl.h>
 #include <arpa/inet.h>
@@ -1434,10 +1551,15 @@ static void run_all_tests(void)
 	test_map_wronly();
 
 	test_reuseport_array();
+
+	test_queuemap(0, NULL);
+	test_stackmap(0, NULL);
 }
 
 int main(void)
 {
+	srand(time(NULL));
+
 	map_flags = 0;
 	run_all_tests();
 

tools/testing/selftests/bpf/test_progs.c

@@ -1735,8 +1735,105 @@ static void test_reference_tracking()
 	bpf_object__close(obj);
 }
 
+enum {
+	QUEUE,
+	STACK,
+};
+
+static void test_queue_stack_map(int type)
+{
+	const int MAP_SIZE = 32;
+	__u32 vals[MAP_SIZE], duration, retval, size, val;
+	int i, err, prog_fd, map_in_fd, map_out_fd;
+	char file[32], buf[128];
+	struct bpf_object *obj;
+	struct iphdr *iph = (void *)buf + sizeof(struct ethhdr);
+
+	/* Fill test values to be used */
+	for (i = 0; i < MAP_SIZE; i++)
+		vals[i] = rand();
+
+	if (type == QUEUE)
+		strncpy(file, "./test_queue_map.o", sizeof(file));
+	else if (type == STACK)
+		strncpy(file, "./test_stack_map.o", sizeof(file));
+	else
+		return;
+
+	err = bpf_prog_load(file, BPF_PROG_TYPE_SCHED_CLS, &obj, &prog_fd);
+	if (err) {
+		error_cnt++;
+		return;
+	}
+
+	map_in_fd = bpf_find_map(__func__, obj, "map_in");
+	if (map_in_fd < 0)
+		goto out;
+
+	map_out_fd = bpf_find_map(__func__, obj, "map_out");
+	if (map_out_fd < 0)
+		goto out;
+
+	/* Push 32 elements to the input map */
+	for (i = 0; i < MAP_SIZE; i++) {
+		err = bpf_map_update_elem(map_in_fd, NULL, &vals[i], 0);
+		if (err) {
+			error_cnt++;
+			goto out;
+		}
+	}
+
+	/* The eBPF program pushes iph.saddr in the output map,
+	 * pops the input map and saves this value in iph.daddr
+	 */
+	for (i = 0; i < MAP_SIZE; i++) {
+		if (type == QUEUE) {
+			val = vals[i];
+			pkt_v4.iph.saddr = vals[i] * 5;
+		} else if (type == STACK) {
+			val = vals[MAP_SIZE - 1 - i];
+			pkt_v4.iph.saddr = vals[MAP_SIZE - 1 - i] * 5;
+		}
+
+		err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4),
+					buf, &size, &retval, &duration);
+		if (err || retval || size != sizeof(pkt_v4) ||
+		    iph->daddr != val)
+			break;
+	}
+
+	CHECK(err || retval || size != sizeof(pkt_v4) || iph->daddr != val,
+	      "bpf_map_pop_elem",
+	      "err %d errno %d retval %d size %d iph->daddr %u\n",
+	      err, errno, retval, size, iph->daddr);
+
+	/* Queue is empty, program should return TC_ACT_SHOT */
+	err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4),
+				buf, &size, &retval, &duration);
+	CHECK(err || retval != 2 /* TC_ACT_SHOT */|| size != sizeof(pkt_v4),
+	      "check-queue-stack-map-empty",
+	      "err %d errno %d retval %d size %d\n",
+	      err, errno, retval, size);
+
+	/* Check that the program pushed elements correctly */
+	for (i = 0; i < MAP_SIZE; i++) {
+		err = bpf_map_lookup_and_delete_elem(map_out_fd, NULL, &val);
+		if (err || val != vals[i] * 5)
+			break;
+	}
+
+	CHECK(i != MAP_SIZE && (err || val != vals[i] * 5),
+	      "bpf_map_push_elem", "err %d value %u\n", err, val);
+
+out:
+	pkt_v4.iph.saddr = 0;
+	bpf_object__close(obj);
+}
+
 int main(void)
 {
+	srand(time(NULL));
+
 	jit_enabled = is_jit_enabled();
 
 	test_pkt_access();
@@ -1757,6 +1854,8 @@ int main(void)
 	test_task_fd_query_rawtp();
 	test_task_fd_query_tp();
 	test_reference_tracking();
+	test_queue_stack_map(QUEUE);
+	test_queue_stack_map(STACK);
 
 	printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt);
 	return error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;

tools/testing/selftests/bpf/test_queue_map.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 Politecnico di Torino
+#define MAP_TYPE BPF_MAP_TYPE_QUEUE
+#include "test_queue_stack_map.h"

tools/testing/selftests/bpf/test_queue_stack_map.h

+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (c) 2018 Politecnico di Torino
+#include <stddef.h>
+#include <string.h>
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <linux/pkt_cls.h>
+#include "bpf_helpers.h"
+
+int _version SEC("version") = 1;
+
+struct bpf_map_def __attribute__ ((section("maps"), used)) map_in = {
+	.type = MAP_TYPE,
+	.key_size = 0,
+	.value_size = sizeof(__u32),
+	.max_entries = 32,
+	.map_flags = 0,
+};
+
+struct bpf_map_def __attribute__ ((section("maps"), used)) map_out = {
+	.type = MAP_TYPE,
+	.key_size = 0,
+	.value_size = sizeof(__u32),
+	.max_entries = 32,
+	.map_flags = 0,
+};
+
+SEC("test")
+int _test(struct __sk_buff *skb)
+{
+	void *data_end = (void *)(long)skb->data_end;
+	void *data = (void *)(long)skb->data;
+	struct ethhdr *eth = (struct ethhdr *)(data);
+	__u32 value;
+	int err;
+
+	if (eth + 1 > data_end)
+		return TC_ACT_SHOT;
+
+	struct iphdr *iph = (struct iphdr *)(eth + 1);
+
+	if (iph + 1 > data_end)
+		return TC_ACT_SHOT;
+
+	err = bpf_map_pop_elem(&map_in, &value);
+	if (err)
+		return TC_ACT_SHOT;
+
+	iph->daddr = value;
+
+	err = bpf_map_push_elem(&map_out, &iph->saddr, 0);
+	if (err)
+		return TC_ACT_SHOT;
+
+	return TC_ACT_OK;
+}
+
+char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/test_stack_map.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 Politecnico di Torino
+#define MAP_TYPE BPF_MAP_TYPE_STACK
+#include "test_queue_stack_map.h"