mirror of
https://github.com/torvalds/linux.git
synced 2024-12-08 03:52:16 +00:00
selftests/bpf: C based test for sysctl and strtoX
Add C based test for a few bpf_sysctl_* helpers and bpf_strtoul. Make sure that sysctl can be identified by name and that multiple integers can be parsed from sysctl value with bpf_strtoul. net/ipv4/tcp_mem is chosen as a testing sysctl, it contains 3 unsigned longs, they all are parsed and compared (val[0] < val[1] < val[2]). Example of output: # ./test_sysctl ... Test case: C prog: deny all writes .. [PASS] Test case: C prog: deny access by name .. [PASS] Test case: C prog: read tcp_mem .. [PASS] Summary: 39 PASSED, 0 FAILED Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
parent
8549ddc832
commit
7568f4cbbe
70
tools/testing/selftests/bpf/progs/test_sysctl_prog.c
Normal file
70
tools/testing/selftests/bpf/progs/test_sysctl_prog.c
Normal file
@ -0,0 +1,70 @@
|
||||
// SPDX-License-Identifier: GPL-2.0
|
||||
// Copyright (c) 2019 Facebook
|
||||
|
||||
#include <stdint.h>
|
||||
#include <string.h>
|
||||
|
||||
#include <linux/stddef.h>
|
||||
#include <linux/bpf.h>
|
||||
|
||||
#include "bpf_helpers.h"
|
||||
#include "bpf_util.h"
|
||||
|
||||
/* Max supported length of a string with unsigned long in base 10 (pow2 - 1). */
|
||||
#define MAX_ULONG_STR_LEN 0xF
|
||||
|
||||
/* Max supported length of sysctl value string (pow2). */
|
||||
#define MAX_VALUE_STR_LEN 0x40
|
||||
|
||||
static __always_inline int is_tcp_mem(struct bpf_sysctl *ctx)
|
||||
{
|
||||
char tcp_mem_name[] = "net/ipv4/tcp_mem";
|
||||
unsigned char i;
|
||||
char name[64];
|
||||
int ret;
|
||||
|
||||
memset(name, 0, sizeof(name));
|
||||
ret = bpf_sysctl_get_name(ctx, name, sizeof(name), 0);
|
||||
if (ret < 0 || ret != sizeof(tcp_mem_name) - 1)
|
||||
return 0;
|
||||
|
||||
#pragma clang loop unroll(full)
|
||||
for (i = 0; i < sizeof(tcp_mem_name); ++i)
|
||||
if (name[i] != tcp_mem_name[i])
|
||||
return 0;
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
SEC("cgroup/sysctl")
|
||||
int sysctl_tcp_mem(struct bpf_sysctl *ctx)
|
||||
{
|
||||
unsigned long tcp_mem[3] = {0, 0, 0};
|
||||
char value[MAX_VALUE_STR_LEN];
|
||||
unsigned char i, off = 0;
|
||||
int ret;
|
||||
|
||||
if (ctx->write)
|
||||
return 0;
|
||||
|
||||
if (!is_tcp_mem(ctx))
|
||||
return 0;
|
||||
|
||||
ret = bpf_sysctl_get_current_value(ctx, value, MAX_VALUE_STR_LEN);
|
||||
if (ret < 0 || ret >= MAX_VALUE_STR_LEN)
|
||||
return 0;
|
||||
|
||||
#pragma clang loop unroll(full)
|
||||
for (i = 0; i < ARRAY_SIZE(tcp_mem); ++i) {
|
||||
ret = bpf_strtoul(value + off, MAX_ULONG_STR_LEN, 0,
|
||||
tcp_mem + i);
|
||||
if (ret <= 0 || ret > MAX_ULONG_STR_LEN)
|
||||
return 0;
|
||||
off += ret & MAX_ULONG_STR_LEN;
|
||||
}
|
||||
|
||||
|
||||
return tcp_mem[0] < tcp_mem[1] && tcp_mem[1] < tcp_mem[2];
|
||||
}
|
||||
|
||||
char _license[] SEC("license") = "GPL";
|
@ -11,6 +11,7 @@
|
||||
#include <linux/filter.h>
|
||||
|
||||
#include <bpf/bpf.h>
|
||||
#include <bpf/libbpf.h>
|
||||
|
||||
#include "bpf_rlimit.h"
|
||||
#include "bpf_util.h"
|
||||
@ -26,6 +27,7 @@ struct sysctl_test {
|
||||
const char *descr;
|
||||
size_t fixup_value_insn;
|
||||
struct bpf_insn insns[MAX_INSNS];
|
||||
const char *prog_file;
|
||||
enum bpf_attach_type attach_type;
|
||||
const char *sysctl;
|
||||
int open_flags;
|
||||
@ -1302,6 +1304,31 @@ static struct sysctl_test tests[] = {
|
||||
.open_flags = O_RDONLY,
|
||||
.result = SUCCESS,
|
||||
},
|
||||
{
|
||||
"C prog: deny all writes",
|
||||
.prog_file = "./test_sysctl_prog.o",
|
||||
.attach_type = BPF_CGROUP_SYSCTL,
|
||||
.sysctl = "net/ipv4/tcp_mem",
|
||||
.open_flags = O_WRONLY,
|
||||
.newval = "123 456 789",
|
||||
.result = OP_EPERM,
|
||||
},
|
||||
{
|
||||
"C prog: deny access by name",
|
||||
.prog_file = "./test_sysctl_prog.o",
|
||||
.attach_type = BPF_CGROUP_SYSCTL,
|
||||
.sysctl = "net/ipv4/route/mtu_expires",
|
||||
.open_flags = O_RDONLY,
|
||||
.result = OP_EPERM,
|
||||
},
|
||||
{
|
||||
"C prog: read tcp_mem",
|
||||
.prog_file = "./test_sysctl_prog.o",
|
||||
.attach_type = BPF_CGROUP_SYSCTL,
|
||||
.sysctl = "net/ipv4/tcp_mem",
|
||||
.open_flags = O_RDONLY,
|
||||
.result = SUCCESS,
|
||||
},
|
||||
};
|
||||
|
||||
static size_t probe_prog_length(const struct bpf_insn *fp)
|
||||
@ -1335,7 +1362,8 @@ static int fixup_sysctl_value(const char *buf, size_t buf_len,
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int load_sysctl_prog(struct sysctl_test *test, const char *sysctl_path)
|
||||
static int load_sysctl_prog_insns(struct sysctl_test *test,
|
||||
const char *sysctl_path)
|
||||
{
|
||||
struct bpf_insn *prog = test->insns;
|
||||
struct bpf_load_program_attr attr;
|
||||
@ -1377,6 +1405,33 @@ static int load_sysctl_prog(struct sysctl_test *test, const char *sysctl_path)
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int load_sysctl_prog_file(struct sysctl_test *test)
|
||||
{
|
||||
struct bpf_prog_load_attr attr;
|
||||
struct bpf_object *obj;
|
||||
int prog_fd;
|
||||
|
||||
memset(&attr, 0, sizeof(struct bpf_prog_load_attr));
|
||||
attr.file = test->prog_file;
|
||||
attr.prog_type = BPF_PROG_TYPE_CGROUP_SYSCTL;
|
||||
|
||||
if (bpf_prog_load_xattr(&attr, &obj, &prog_fd)) {
|
||||
if (test->result != LOAD_REJECT)
|
||||
log_err(">>> Loading program (%s) error.\n",
|
||||
test->prog_file);
|
||||
return -1;
|
||||
}
|
||||
|
||||
return prog_fd;
|
||||
}
|
||||
|
||||
static int load_sysctl_prog(struct sysctl_test *test, const char *sysctl_path)
|
||||
{
|
||||
return test->prog_file
|
||||
? load_sysctl_prog_file(test)
|
||||
: load_sysctl_prog_insns(test, sysctl_path);
|
||||
}
|
||||
|
||||
static int access_sysctl(const char *sysctl_path,
|
||||
const struct sysctl_test *test)
|
||||
{
|
||||
|
Loading…
Reference in New Issue
Block a user