bpf: add a testsuite for eBPF maps

. check error conditions and sanity of hash and array map APIs
. check large maps (that kernel gracefully switches to vmalloc from kmalloc)
. check multi-process parallel access and stress test

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexei Starovoitov 2014-11-13 17:36:48 -08:00 коммит произвёл David S. Miller
Родитель a1854d6ac0
Коммит ffb65f27a1
4 изменённых файлов: 296 добавлений и 3 удалений

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@ -2,9 +2,10 @@
obj- := dummy.o
# List of programs to build
hostprogs-y := test_verifier
hostprogs-y := test_verifier test_maps
test_verifier-objs := test_verifier.o libbpf.o
test_maps-objs := test_maps.o libbpf.o
# Tell kbuild to always build the programs
always := $(hostprogs-y)

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@ -27,12 +27,13 @@ int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
}
int bpf_update_elem(int fd, void *key, void *value)
int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags)
{
union bpf_attr attr = {
.map_fd = fd,
.key = ptr_to_u64(key),
.value = ptr_to_u64(value),
.flags = flags,
};
return syscall(__NR_bpf, BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));

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@ -6,7 +6,7 @@ struct bpf_insn;
int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
int max_entries);
int bpf_update_elem(int fd, void *key, void *value);
int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags);
int bpf_lookup_elem(int fd, void *key, void *value);
int bpf_delete_elem(int fd, void *key);
int bpf_get_next_key(int fd, void *key, void *next_key);

291
samples/bpf/test_maps.c Normal file
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@ -0,0 +1,291 @@
/*
* Testsuite for eBPF maps
*
* Copyright (c) 2014 PLUMgrid, http://plumgrid.com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#include <stdio.h>
#include <unistd.h>
#include <linux/bpf.h>
#include <errno.h>
#include <string.h>
#include <assert.h>
#include <sys/wait.h>
#include <stdlib.h>
#include "libbpf.h"
/* sanity tests for map API */
static void test_hashmap_sanity(int i, void *data)
{
long long key, next_key, value;
int map_fd;
map_fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value), 2);
if (map_fd < 0) {
printf("failed to create hashmap '%s'\n", strerror(errno));
exit(1);
}
key = 1;
value = 1234;
/* insert key=1 element */
assert(bpf_update_elem(map_fd, &key, &value, BPF_ANY) == 0);
value = 0;
/* BPF_NOEXIST means: add new element if it doesn't exist */
assert(bpf_update_elem(map_fd, &key, &value, BPF_NOEXIST) == -1 &&
/* key=1 already exists */
errno == EEXIST);
assert(bpf_update_elem(map_fd, &key, &value, -1) == -1 && errno == EINVAL);
/* check that key=1 can be found */
assert(bpf_lookup_elem(map_fd, &key, &value) == 0 && value == 1234);
key = 2;
/* check that key=2 is not found */
assert(bpf_lookup_elem(map_fd, &key, &value) == -1 && errno == ENOENT);
/* BPF_EXIST means: update existing element */
assert(bpf_update_elem(map_fd, &key, &value, BPF_EXIST) == -1 &&
/* key=2 is not there */
errno == ENOENT);
/* insert key=2 element */
assert(bpf_update_elem(map_fd, &key, &value, BPF_NOEXIST) == 0);
/* key=1 and key=2 were inserted, check that key=0 cannot be inserted
* due to max_entries limit
*/
key = 0;
assert(bpf_update_elem(map_fd, &key, &value, BPF_NOEXIST) == -1 &&
errno == E2BIG);
/* check that key = 0 doesn't exist */
assert(bpf_delete_elem(map_fd, &key) == -1 && errno == ENOENT);
/* iterate over two elements */
assert(bpf_get_next_key(map_fd, &key, &next_key) == 0 &&
next_key == 2);
assert(bpf_get_next_key(map_fd, &next_key, &next_key) == 0 &&
next_key == 1);
assert(bpf_get_next_key(map_fd, &next_key, &next_key) == -1 &&
errno == ENOENT);
/* delete both elements */
key = 1;
assert(bpf_delete_elem(map_fd, &key) == 0);
key = 2;
assert(bpf_delete_elem(map_fd, &key) == 0);
assert(bpf_delete_elem(map_fd, &key) == -1 && errno == ENOENT);
key = 0;
/* check that map is empty */
assert(bpf_get_next_key(map_fd, &key, &next_key) == -1 &&
errno == ENOENT);
close(map_fd);
}
static void test_arraymap_sanity(int i, void *data)
{
int key, next_key, map_fd;
long long value;
map_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, sizeof(key), sizeof(value), 2);
if (map_fd < 0) {
printf("failed to create arraymap '%s'\n", strerror(errno));
exit(1);
}
key = 1;
value = 1234;
/* insert key=1 element */
assert(bpf_update_elem(map_fd, &key, &value, BPF_ANY) == 0);
value = 0;
assert(bpf_update_elem(map_fd, &key, &value, BPF_NOEXIST) == -1 &&
errno == EEXIST);
/* check that key=1 can be found */
assert(bpf_lookup_elem(map_fd, &key, &value) == 0 && value == 1234);
key = 0;
/* check that key=0 is also found and zero initialized */
assert(bpf_lookup_elem(map_fd, &key, &value) == 0 && value == 0);
/* key=0 and key=1 were inserted, check that key=2 cannot be inserted
* due to max_entries limit
*/
key = 2;
assert(bpf_update_elem(map_fd, &key, &value, BPF_EXIST) == -1 &&
errno == E2BIG);
/* check that key = 2 doesn't exist */
assert(bpf_lookup_elem(map_fd, &key, &value) == -1 && errno == ENOENT);
/* iterate over two elements */
assert(bpf_get_next_key(map_fd, &key, &next_key) == 0 &&
next_key == 0);
assert(bpf_get_next_key(map_fd, &next_key, &next_key) == 0 &&
next_key == 1);
assert(bpf_get_next_key(map_fd, &next_key, &next_key) == -1 &&
errno == ENOENT);
/* delete shouldn't succeed */
key = 1;
assert(bpf_delete_elem(map_fd, &key) == -1 && errno == EINVAL);
close(map_fd);
}
#define MAP_SIZE (32 * 1024)
static void test_map_large(void)
{
struct bigkey {
int a;
char b[116];
long long c;
} key;
int map_fd, i, value;
/* allocate 4Mbyte of memory */
map_fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value),
MAP_SIZE);
if (map_fd < 0) {
printf("failed to create large map '%s'\n", strerror(errno));
exit(1);
}
for (i = 0; i < MAP_SIZE; i++) {
key = (struct bigkey) {.c = i};
value = i;
assert(bpf_update_elem(map_fd, &key, &value, BPF_NOEXIST) == 0);
}
key.c = -1;
assert(bpf_update_elem(map_fd, &key, &value, BPF_NOEXIST) == -1 &&
errno == E2BIG);
/* iterate through all elements */
for (i = 0; i < MAP_SIZE; i++)
assert(bpf_get_next_key(map_fd, &key, &key) == 0);
assert(bpf_get_next_key(map_fd, &key, &key) == -1 && errno == ENOENT);
key.c = 0;
assert(bpf_lookup_elem(map_fd, &key, &value) == 0 && value == 0);
key.a = 1;
assert(bpf_lookup_elem(map_fd, &key, &value) == -1 && errno == ENOENT);
close(map_fd);
}
/* fork N children and wait for them to complete */
static void run_parallel(int tasks, void (*fn)(int i, void *data), void *data)
{
pid_t pid[tasks];
int i;
for (i = 0; i < tasks; i++) {
pid[i] = fork();
if (pid[i] == 0) {
fn(i, data);
exit(0);
} else if (pid[i] == -1) {
printf("couldn't spawn #%d process\n", i);
exit(1);
}
}
for (i = 0; i < tasks; i++) {
int status;
assert(waitpid(pid[i], &status, 0) == pid[i]);
assert(status == 0);
}
}
static void test_map_stress(void)
{
run_parallel(100, test_hashmap_sanity, NULL);
run_parallel(100, test_arraymap_sanity, NULL);
}
#define TASKS 1024
#define DO_UPDATE 1
#define DO_DELETE 0
static void do_work(int fn, void *data)
{
int map_fd = ((int *)data)[0];
int do_update = ((int *)data)[1];
int i;
int key, value;
for (i = fn; i < MAP_SIZE; i += TASKS) {
key = value = i;
if (do_update)
assert(bpf_update_elem(map_fd, &key, &value, BPF_NOEXIST) == 0);
else
assert(bpf_delete_elem(map_fd, &key) == 0);
}
}
static void test_map_parallel(void)
{
int i, map_fd, key = 0, value = 0;
int data[2];
map_fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value),
MAP_SIZE);
if (map_fd < 0) {
printf("failed to create map for parallel test '%s'\n",
strerror(errno));
exit(1);
}
data[0] = map_fd;
data[1] = DO_UPDATE;
/* use the same map_fd in children to add elements to this map
* child_0 adds key=0, key=1024, key=2048, ...
* child_1 adds key=1, key=1025, key=2049, ...
* child_1023 adds key=1023, ...
*/
run_parallel(TASKS, do_work, data);
/* check that key=0 is already there */
assert(bpf_update_elem(map_fd, &key, &value, BPF_NOEXIST) == -1 &&
errno == EEXIST);
/* check that all elements were inserted */
key = -1;
for (i = 0; i < MAP_SIZE; i++)
assert(bpf_get_next_key(map_fd, &key, &key) == 0);
assert(bpf_get_next_key(map_fd, &key, &key) == -1 && errno == ENOENT);
/* another check for all elements */
for (i = 0; i < MAP_SIZE; i++) {
key = MAP_SIZE - i - 1;
assert(bpf_lookup_elem(map_fd, &key, &value) == 0 &&
value == key);
}
/* now let's delete all elemenets in parallel */
data[1] = DO_DELETE;
run_parallel(TASKS, do_work, data);
/* nothing should be left */
key = -1;
assert(bpf_get_next_key(map_fd, &key, &key) == -1 && errno == ENOENT);
}
int main(void)
{
test_hashmap_sanity(0, NULL);
test_arraymap_sanity(0, NULL);
test_map_large();
test_map_parallel();
test_map_stress();
printf("test_maps: OK\n");
return 0;
}