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bpf: Add tests for map-in-map

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Test cases for array of maps and hash of maps.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Martin KaFai Lau 2017-03-22 10:00:35 -07:00 committed by David S. Miller
parent bcc6b1b7eb
commit fb30d4b712
9 changed files with 451 additions and 18 deletions
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4
samples/bpf/Makefile
View File

@ -34,6 +34,7 @@ hostprogs-y += sampleip
hostprogs-y += tc_l2_redirect
hostprogs-y += lwt_len_hist
hostprogs-y += xdp_tx_iptunnel
hostprogs-y += test_map_in_map
# Libbpf dependencies
LIBBPF := ../../tools/lib/bpf/bpf.o
@ -72,6 +73,7 @@ sampleip-objs := bpf_load.o $(LIBBPF) sampleip_user.o
tc_l2_redirect-objs := bpf_load.o $(LIBBPF) tc_l2_redirect_user.o
lwt_len_hist-objs := bpf_load.o $(LIBBPF) lwt_len_hist_user.o
xdp_tx_iptunnel-objs := bpf_load.o $(LIBBPF) xdp_tx_iptunnel_user.o
test_map_in_map-objs := bpf_load.o $(LIBBPF) test_map_in_map_user.o
# Tell kbuild to always build the programs
always := $(hostprogs-y)
@ -105,6 +107,7 @@ always += trace_event_kern.o
always += sampleip_kern.o
always += lwt_len_hist_kern.o
always += xdp_tx_iptunnel_kern.o
always += test_map_in_map_kern.o
HOSTCFLAGS += -I$(objtree)/usr/include
HOSTCFLAGS += -I$(srctree)/tools/lib/
@ -139,6 +142,7 @@ HOSTLOADLIBES_sampleip += -lelf
HOSTLOADLIBES_tc_l2_redirect += -l elf
HOSTLOADLIBES_lwt_len_hist += -l elf
HOSTLOADLIBES_xdp_tx_iptunnel += -lelf
HOSTLOADLIBES_test_map_in_map += -lelf
# Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
# make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang

1
samples/bpf/bpf_helpers.h
View File

@ -80,6 +80,7 @@ struct bpf_map_def {
unsigned int value_size;
unsigned int max_entries;
unsigned int map_flags;
unsigned int inner_map_idx;
};
static int (*bpf_skb_load_bytes)(void *ctx, int off, void *to, int len) =

22
samples/bpf/bpf_load.c
View File

@ -43,6 +43,7 @@ struct bpf_map_def {
unsigned int value_size;
unsigned int max_entries;
unsigned int map_flags;
unsigned int inner_map_idx;
};
static int populate_prog_array(const char *event, int prog_fd)
@ -198,11 +199,22 @@ static int load_maps(struct bpf_map_def *maps, int len)
for (i = 0; i < len / sizeof(struct bpf_map_def); i++) {
map_fd[i] = bpf_create_map(maps[i].type,
maps[i].key_size,
maps[i].value_size,
maps[i].max_entries,
maps[i].map_flags);
if (maps[i].type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
maps[i].type == BPF_MAP_TYPE_HASH_OF_MAPS) {
int inner_map_fd = map_fd[maps[i].inner_map_idx];
map_fd[i] = bpf_create_map_in_map(maps[i].type,
maps[i].key_size,
inner_map_fd,
maps[i].max_entries,
maps[i].map_flags);
} else {
map_fd[i] = bpf_create_map(maps[i].type,
maps[i].key_size,
maps[i].value_size,
maps[i].max_entries,
maps[i].map_flags);
}
if (map_fd[i] < 0) {
printf("failed to create a map: %d %s\n",
errno, strerror(errno));

173
samples/bpf/test_map_in_map_kern.c Normal file
View File

@ -0,0 +1,173 @@
/*
* Copyright (c) 2017 Facebook
*
* 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.
*/
#define KBUILD_MODNAME "foo"
#include <linux/ptrace.h>
#include <linux/version.h>
#include <uapi/linux/bpf.h>
#include <uapi/linux/in6.h>
#include "bpf_helpers.h"
#define MAX_NR_PORTS 65536
/* map #0 */
struct bpf_map_def SEC("maps") port_a = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(u32),
.value_size = sizeof(int),
.max_entries = MAX_NR_PORTS,
};
/* map #1 */
struct bpf_map_def SEC("maps") port_h = {
.type = BPF_MAP_TYPE_HASH,
.key_size = sizeof(u32),
.value_size = sizeof(int),
.max_entries = 1,
};
/* map #2 */
struct bpf_map_def SEC("maps") reg_result_h = {
.type = BPF_MAP_TYPE_HASH,
.key_size = sizeof(u32),
.value_size = sizeof(int),
.max_entries = 1,
};
/* map #3 */
struct bpf_map_def SEC("maps") inline_result_h = {
.type = BPF_MAP_TYPE_HASH,
.key_size = sizeof(u32),
.value_size = sizeof(int),
.max_entries = 1,
};
/* map #4 */ /* Test case #0 */
struct bpf_map_def SEC("maps") a_of_port_a = {
.type = BPF_MAP_TYPE_ARRAY_OF_MAPS,
.key_size = sizeof(u32),
.inner_map_idx = 0, /* map_fd[0] is port_a */
.max_entries = MAX_NR_PORTS,
};
/* map #5 */ /* Test case #1 */
struct bpf_map_def SEC("maps") h_of_port_a = {
.type = BPF_MAP_TYPE_HASH_OF_MAPS,
.key_size = sizeof(u32),
.inner_map_idx = 0, /* map_fd[0] is port_a */
.max_entries = 1,
};
/* map #6 */ /* Test case #2 */
struct bpf_map_def SEC("maps") h_of_port_h = {
.type = BPF_MAP_TYPE_HASH_OF_MAPS,
.key_size = sizeof(u32),
.inner_map_idx = 1, /* map_fd[1] is port_h */
.max_entries = 1,
};
static __always_inline int do_reg_lookup(void *inner_map, u32 port)
{
int *result;
result = bpf_map_lookup_elem(inner_map, &port);
return result ? *result : -ENOENT;
}
static __always_inline int do_inline_array_lookup(void *inner_map, u32 port)
{
int *result;
if (inner_map != &port_a)
return -EINVAL;
result = bpf_map_lookup_elem(&port_a, &port);
return result ? *result : -ENOENT;
}
static __always_inline int do_inline_hash_lookup(void *inner_map, u32 port)
{
int *result;
if (inner_map != &port_h)
return -EINVAL;
result = bpf_map_lookup_elem(&port_h, &port);
return result ? *result : -ENOENT;
}
SEC("kprobe/sys_connect")
int trace_sys_connect(struct pt_regs *ctx)
{
struct sockaddr_in6 *in6;
u16 test_case, port, dst6[8];
int addrlen, ret, inline_ret, ret_key = 0;
u32 port_key;
void *outer_map, *inner_map;
bool inline_hash = false;
in6 = (struct sockaddr_in6 *)PT_REGS_PARM2(ctx);
addrlen = (int)PT_REGS_PARM3(ctx);
if (addrlen != sizeof(*in6))
return 0;
ret = bpf_probe_read(dst6, sizeof(dst6), &in6->sin6_addr);
if (ret) {
inline_ret = ret;
goto done;
}
if (dst6[0] != 0xdead || dst6[1] != 0xbeef)
return 0;
test_case = dst6[7];
ret = bpf_probe_read(&port, sizeof(port), &in6->sin6_port);
if (ret) {
inline_ret = ret;
goto done;
}
port_key = port;
ret = -ENOENT;
if (test_case == 0) {
outer_map = &a_of_port_a;
} else if (test_case == 1) {
outer_map = &h_of_port_a;
} else if (test_case == 2) {
outer_map = &h_of_port_h;
} else {
ret = __LINE__;
inline_ret = ret;
goto done;
}
inner_map = bpf_map_lookup_elem(outer_map, &port_key);
if (!inner_map) {
ret = __LINE__;
inline_ret = ret;
goto done;
}
ret = do_reg_lookup(inner_map, port_key);
if (test_case == 0 || test_case == 1)
inline_ret = do_inline_array_lookup(inner_map, port_key);
else
inline_ret = do_inline_hash_lookup(inner_map, port_key);
done:
bpf_map_update_elem(&reg_result_h, &ret_key, &ret, BPF_ANY);
bpf_map_update_elem(&inline_result_h, &ret_key, &inline_ret, BPF_ANY);
return 0;
}
char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;

116
samples/bpf/test_map_in_map_user.c Normal file
View File

@ -0,0 +1,116 @@
/*
* Copyright (c) 2017 Facebook
*
* 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 <sys/resource.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <stdint.h>
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include "libbpf.h"
#include "bpf_load.h"
#define PORT_A (map_fd[0])
#define PORT_H (map_fd[1])
#define REG_RESULT_H (map_fd[2])
#define INLINE_RESULT_H (map_fd[3])
#define A_OF_PORT_A (map_fd[4]) /* Test case #0 */
#define H_OF_PORT_A (map_fd[5]) /* Test case #1 */
#define H_OF_PORT_H (map_fd[6]) /* Test case #2 */
static const char * const test_names[] = {
"Array of Array",
"Hash of Array",
"Hash of Hash",
};
#define NR_TESTS (sizeof(test_names) / sizeof(*test_names))
static void populate_map(uint32_t port_key, int magic_result)
{
int ret;
ret = bpf_map_update_elem(PORT_A, &port_key, &magic_result, BPF_ANY);
assert(!ret);
ret = bpf_map_update_elem(PORT_H, &port_key, &magic_result,
BPF_NOEXIST);
assert(!ret);
ret = bpf_map_update_elem(A_OF_PORT_A, &port_key, &PORT_A, BPF_ANY);
assert(!ret);
ret = bpf_map_update_elem(H_OF_PORT_A, &port_key, &PORT_A, BPF_NOEXIST);
assert(!ret);
ret = bpf_map_update_elem(H_OF_PORT_H, &port_key, &PORT_H, BPF_NOEXIST);
assert(!ret);
}
static void test_map_in_map(void)
{
struct sockaddr_in6 in6 = { .sin6_family = AF_INET6 };
uint32_t result_key = 0, port_key;
int result, inline_result;
int magic_result = 0xfaceb00c;
int ret;
int i;
port_key = rand() & 0x00FF;
populate_map(port_key, magic_result);
in6.sin6_addr.s6_addr16[0] = 0xdead;
in6.sin6_addr.s6_addr16[1] = 0xbeef;
in6.sin6_port = port_key;
for (i = 0; i < NR_TESTS; i++) {
printf("%s: ", test_names[i]);
in6.sin6_addr.s6_addr16[7] = i;
ret = connect(-1, (struct sockaddr *)&in6, sizeof(in6));
assert(ret == -1 && errno == EBADF);
ret = bpf_map_lookup_elem(REG_RESULT_H, &result_key, &result);
assert(!ret);
ret = bpf_map_lookup_elem(INLINE_RESULT_H, &result_key,
&inline_result);
assert(!ret);
if (result != magic_result || inline_result != magic_result) {
printf("Error. result:%d inline_result:%d\n",
result, inline_result);
exit(1);
}
bpf_map_delete_elem(REG_RESULT_H, &result_key);
bpf_map_delete_elem(INLINE_RESULT_H, &result_key);
printf("Pass\n");
}
}
int main(int argc, char **argv)
{
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
char filename[256];
assert(!setrlimit(RLIMIT_MEMLOCK, &r));
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
if (load_bpf_file(filename)) {
printf("%s", bpf_log_buf);
return 1;
}
test_map_in_map();
return 0;
}

3
tools/include/uapi/linux/bpf.h
View File

@ -96,6 +96,8 @@ enum bpf_map_type {
BPF_MAP_TYPE_LRU_HASH,
BPF_MAP_TYPE_LRU_PERCPU_HASH,
BPF_MAP_TYPE_LPM_TRIE,
BPF_MAP_TYPE_ARRAY_OF_MAPS,
BPF_MAP_TYPE_HASH_OF_MAPS,
};
enum bpf_prog_type {
@ -152,6 +154,7 @@ union bpf_attr {
__u32 value_size; /* size of value in bytes */
__u32 max_entries; /* max number of entries in a map */
__u32 map_flags; /* prealloc or not */
__u32 inner_map_fd; /* fd pointing to the inner map */
};
struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */

17
tools/lib/bpf/bpf.c
View File

@ -69,6 +69,23 @@ int bpf_create_map(enum bpf_map_type map_type, int key_size,
return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
}
int bpf_create_map_in_map(enum bpf_map_type map_type, int key_size,
int inner_map_fd, int max_entries, __u32 map_flags)
{
union bpf_attr attr;
memset(&attr, '\0', sizeof(attr));
attr.map_type = map_type;
attr.key_size = key_size;
attr.value_size = 4;
attr.inner_map_fd = inner_map_fd;
attr.max_entries = max_entries;
attr.map_flags = map_flags;
return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
}
int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
size_t insns_cnt, const char *license,
__u32 kern_version, char *log_buf, size_t log_buf_sz)

2
tools/lib/bpf/bpf.h
View File

@ -26,6 +26,8 @@
int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
int max_entries, __u32 map_flags);
int bpf_create_map_in_map(enum bpf_map_type map_type, int key_size,
int inner_map_fd, int max_entries, __u32 map_flags);
/* Recommend log buffer size */
#define BPF_LOG_BUF_SIZE 65536

131
tools/testing/selftests/bpf/test_verifier.c
View File

@ -38,6 +38,7 @@
#define MAX_INSNS 512
#define MAX_FIXUPS 8
#define MAX_NR_MAPS 4
struct bpf_test {
const char *descr;
@ -45,6 +46,7 @@ struct bpf_test {
int fixup_map1[MAX_FIXUPS];
int fixup_map2[MAX_FIXUPS];
int fixup_prog[MAX_FIXUPS];
int fixup_map_in_map[MAX_FIXUPS];
const char *errstr;
const char *errstr_unpriv;
enum {
@ -4452,7 +4454,76 @@ static struct bpf_test tests[] = {
.errstr = "R0 min value is negative, either use unsigned index or do a if (index >=0) check.",
.result = REJECT,
.result_unpriv = REJECT,
}
},
{
"map in map access",
.insns = {
BPF_ST_MEM(0, BPF_REG_10, -4, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5),
BPF_ST_MEM(0, BPF_REG_10, -4, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_MOV64_REG(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_in_map = { 3 },
.result = ACCEPT,
},
{
"invalid inner map pointer",
.insns = {
BPF_ST_MEM(0, BPF_REG_10, -4, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
BPF_ST_MEM(0, BPF_REG_10, -4, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_MOV64_REG(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_in_map = { 3 },
.errstr = "R1 type=inv expected=map_ptr",
.errstr_unpriv = "R1 pointer arithmetic prohibited",
.result = REJECT,
},
{
"forgot null checking on the inner map pointer",
.insns = {
BPF_ST_MEM(0, BPF_REG_10, -4, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_ST_MEM(0, BPF_REG_10, -4, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_MOV64_REG(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_in_map = { 3 },
.errstr = "R1 type=map_value_or_null expected=map_ptr",
.result = REJECT,
},
};
static int probe_filter_length(const struct bpf_insn *fp)
@ -4489,42 +4560,73 @@ static int create_prog_array(void)
return fd;
}
static int create_map_in_map(void)
{
int inner_map_fd, outer_map_fd;
inner_map_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, sizeof(int),
sizeof(int), 1, 0);
if (inner_map_fd < 0) {
printf("Failed to create array '%s'!\n", strerror(errno));
return inner_map_fd;
}
outer_map_fd = bpf_create_map_in_map(BPF_MAP_TYPE_ARRAY_OF_MAPS,
sizeof(int), inner_map_fd, 1, 0);
if (outer_map_fd < 0)
printf("Failed to create array of maps '%s'!\n",
strerror(errno));
close(inner_map_fd);
return outer_map_fd;
}
static char bpf_vlog[32768];
static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog,
int *fd_f1, int *fd_f2, int *fd_f3)
int *map_fds)
{
int *fixup_map1 = test->fixup_map1;
int *fixup_map2 = test->fixup_map2;
int *fixup_prog = test->fixup_prog;
int *fixup_map_in_map = test->fixup_map_in_map;
/* Allocating HTs with 1 elem is fine here, since we only test
* for verifier and not do a runtime lookup, so the only thing
* that really matters is value size in this case.
*/
if (*fixup_map1) {
*fd_f1 = create_map(sizeof(long long), 1);
map_fds[0] = create_map(sizeof(long long), 1);
do {
prog[*fixup_map1].imm = *fd_f1;
prog[*fixup_map1].imm = map_fds[0];
fixup_map1++;
} while (*fixup_map1);
}
if (*fixup_map2) {
*fd_f2 = create_map(sizeof(struct test_val), 1);
map_fds[1] = create_map(sizeof(struct test_val), 1);
do {
prog[*fixup_map2].imm = *fd_f2;
prog[*fixup_map2].imm = map_fds[1];
fixup_map2++;
} while (*fixup_map2);
}
if (*fixup_prog) {
*fd_f3 = create_prog_array();
map_fds[2] = create_prog_array();
do {
prog[*fixup_prog].imm = *fd_f3;
prog[*fixup_prog].imm = map_fds[2];
fixup_prog++;
} while (*fixup_prog);
}
if (*fixup_map_in_map) {
map_fds[3] = create_map_in_map();
do {
prog[*fixup_map_in_map].imm = map_fds[3];
fixup_map_in_map++;
} while (*fixup_map_in_map);
}
}
static void do_test_single(struct bpf_test *test, bool unpriv,
@ -4533,11 +4635,15 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
struct bpf_insn *prog = test->insns;
int prog_len = probe_filter_length(prog);
int prog_type = test->prog_type;
int fd_f1 = -1, fd_f2 = -1, fd_f3 = -1;
int map_fds[MAX_NR_MAPS];
int fd_prog, expected_ret;
const char *expected_err;
int i;
do_test_fixup(test, prog, &fd_f1, &fd_f2, &fd_f3);
for (i = 0; i < MAX_NR_MAPS; i++)
map_fds[i] = -1;
do_test_fixup(test, prog, map_fds);
fd_prog = bpf_load_program(prog_type ? : BPF_PROG_TYPE_SOCKET_FILTER,
prog, prog_len, "GPL", 0, bpf_vlog,
@ -4568,9 +4674,8 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
printf("OK\n");
close_fds:
close(fd_prog);
close(fd_f1);
close(fd_f2);
close(fd_f3);
for (i = 0; i < MAX_NR_MAPS; i++)
close(map_fds[i]);
sched_yield();
return;
fail_log: