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selftests/bpf: Selftest for sys_bind post-hooks.

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Add selftest for attach types `BPF_CGROUP_INET4_POST_BIND` and
`BPF_CGROUP_INET6_POST_BIND`.

The main things tested are:
* prog load behaves as expected (valid/invalid accesses in prog);
* prog attach behaves as expected (load- vs attach-time attach types);
* `BPF_CGROUP_INET_SOCK_CREATE` can be attached in a backward compatible
  way;
* post-hooks return expected result and errno.

Example:
  # ./test_sock
  Test case: bind4 load with invalid access: src_ip6 .. [PASS]
  Test case: bind4 load with invalid access: mark .. [PASS]
  Test case: bind6 load with invalid access: src_ip4 .. [PASS]
  Test case: sock_create load with invalid access: src_port .. [PASS]
  Test case: sock_create load w/o expected_attach_type (compat mode) ..
  [PASS]
  Test case: sock_create load w/ expected_attach_type .. [PASS]
  Test case: attach type mismatch bind4 vs bind6 .. [PASS]
  Test case: attach type mismatch bind6 vs bind4 .. [PASS]
  Test case: attach type mismatch default vs bind4 .. [PASS]
  Test case: attach type mismatch bind6 vs sock_create .. [PASS]
  Test case: bind4 reject all .. [PASS]
  Test case: bind6 reject all .. [PASS]
  Test case: bind6 deny specific IP & port .. [PASS]
  Test case: bind4 allow specific IP & port .. [PASS]
  Test case: bind4 allow all .. [PASS]
  Test case: bind6 allow all .. [PASS]
  Summary: 16 PASSED, 0 FAILED

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Andrey Ignatov 2018-03-30 15:08:08 -07:00 committed by Daniel Borkmann
parent aac3fc320d
commit 1d436885b2
3 changed files with 493 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
tools/include/uapi/linux/bpf.h
View File

@ -152,6 +152,8 @@ enum bpf_attach_type {
BPF_CGROUP_INET6_BIND,
BPF_CGROUP_INET4_CONNECT,
BPF_CGROUP_INET6_CONNECT,
BPF_CGROUP_INET4_POST_BIND,
BPF_CGROUP_INET6_POST_BIND,
__MAX_BPF_ATTACH_TYPE
};
@ -947,6 +949,15 @@ struct bpf_sock {
__u32 protocol;
__u32 mark;
__u32 priority;
__u32 src_ip4; /* Allows 1,2,4-byte read.
* Stored in network byte order.
*/
__u32 src_ip6[4]; /* Allows 1,2,4-byte read.
* Stored in network byte order.
*/
__u32 src_port; /* Allows 4-byte read.
* Stored in host byte order
*/
};
#define XDP_PACKET_HEADROOM 256

4
tools/testing/selftests/bpf/Makefile
View File

@ -23,7 +23,8 @@ urandom_read: urandom_read.c
# Order correspond to 'make run_tests' order
TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \
test_align test_verifier_log test_dev_cgroup test_tcpbpf_user test_sock_addr
test_align test_verifier_log test_dev_cgroup test_tcpbpf_user \
test_sock test_sock_addr
TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test_obj_id.o \
test_pkt_md_access.o test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o \
@ -52,6 +53,7 @@ $(TEST_GEN_PROGS): $(BPFOBJ)
$(TEST_GEN_PROGS_EXTENDED): $(OUTPUT)/libbpf.a
$(OUTPUT)/test_dev_cgroup: cgroup_helpers.c
$(OUTPUT)/test_sock: cgroup_helpers.c
$(OUTPUT)/test_sock_addr: cgroup_helpers.c
.PHONY: force

479
tools/testing/selftests/bpf/test_sock.c Normal file
View File

@ -0,0 +1,479 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2018 Facebook
#include <stdio.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <linux/filter.h>
#include <bpf/bpf.h>
#include "cgroup_helpers.h"
#ifndef ARRAY_SIZE
# define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
#endif
#define CG_PATH "/foo"
#define MAX_INSNS 512
char bpf_log_buf[BPF_LOG_BUF_SIZE];
struct sock_test {
const char *descr;
/* BPF prog properties */
struct bpf_insn insns[MAX_INSNS];
enum bpf_attach_type expected_attach_type;
enum bpf_attach_type attach_type;
/* Socket properties */
int domain;
int type;
/* Endpoint to bind() to */
const char *ip;
unsigned short port;
/* Expected test result */
enum {
LOAD_REJECT,
ATTACH_REJECT,
BIND_REJECT,
SUCCESS,
} result;
};
static struct sock_test tests[] = {
{
"bind4 load with invalid access: src_ip6",
.insns = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock, src_ip6[0])),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET4_POST_BIND,
BPF_CGROUP_INET4_POST_BIND,
0,
0,
NULL,
0,
LOAD_REJECT,
},
{
"bind4 load with invalid access: mark",
.insns = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock, mark)),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET4_POST_BIND,
BPF_CGROUP_INET4_POST_BIND,
0,
0,
NULL,
0,
LOAD_REJECT,
},
{
"bind6 load with invalid access: src_ip4",
.insns = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock, src_ip4)),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET6_POST_BIND,
BPF_CGROUP_INET6_POST_BIND,
0,
0,
NULL,
0,
LOAD_REJECT,
},
{
"sock_create load with invalid access: src_port",
.insns = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock, src_port)),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET_SOCK_CREATE,
BPF_CGROUP_INET_SOCK_CREATE,
0,
0,
NULL,
0,
LOAD_REJECT,
},
{
"sock_create load w/o expected_attach_type (compat mode)",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
0,
BPF_CGROUP_INET_SOCK_CREATE,
AF_INET,
SOCK_STREAM,
"127.0.0.1",
8097,
SUCCESS,
},
{
"sock_create load w/ expected_attach_type",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET_SOCK_CREATE,
BPF_CGROUP_INET_SOCK_CREATE,
AF_INET,
SOCK_STREAM,
"127.0.0.1",
8097,
SUCCESS,
},
{
"attach type mismatch bind4 vs bind6",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET4_POST_BIND,
BPF_CGROUP_INET6_POST_BIND,
0,
0,
NULL,
0,
ATTACH_REJECT,
},
{
"attach type mismatch bind6 vs bind4",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET6_POST_BIND,
BPF_CGROUP_INET4_POST_BIND,
0,
0,
NULL,
0,
ATTACH_REJECT,
},
{
"attach type mismatch default vs bind4",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
0,
BPF_CGROUP_INET4_POST_BIND,
0,
0,
NULL,
0,
ATTACH_REJECT,
},
{
"attach type mismatch bind6 vs sock_create",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET6_POST_BIND,
BPF_CGROUP_INET_SOCK_CREATE,
0,
0,
NULL,
0,
ATTACH_REJECT,
},
{
"bind4 reject all",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET4_POST_BIND,
BPF_CGROUP_INET4_POST_BIND,
AF_INET,
SOCK_STREAM,
"0.0.0.0",
0,
BIND_REJECT,
},
{
"bind6 reject all",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET6_POST_BIND,
BPF_CGROUP_INET6_POST_BIND,
AF_INET6,
SOCK_STREAM,
"::",
0,
BIND_REJECT,
},
{
"bind6 deny specific IP & port",
.insns = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
/* if (ip == expected && port == expected) */
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock, src_ip6[3])),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x01000000, 4),
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock, src_port)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x2001, 2),
/* return DENY; */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_JMP_A(1),
/* else return ALLOW; */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET6_POST_BIND,
BPF_CGROUP_INET6_POST_BIND,
AF_INET6,
SOCK_STREAM,
"::1",
8193,
BIND_REJECT,
},
{
"bind4 allow specific IP & port",
.insns = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
/* if (ip == expected && port == expected) */
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock, src_ip4)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x0100007F, 4),
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
offsetof(struct bpf_sock, src_port)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2),
/* return ALLOW; */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_JMP_A(1),
/* else return DENY; */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET4_POST_BIND,
BPF_CGROUP_INET4_POST_BIND,
AF_INET,
SOCK_STREAM,
"127.0.0.1",
4098,
SUCCESS,
},
{
"bind4 allow all",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET4_POST_BIND,
BPF_CGROUP_INET4_POST_BIND,
AF_INET,
SOCK_STREAM,
"0.0.0.0",
0,
SUCCESS,
},
{
"bind6 allow all",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
BPF_CGROUP_INET6_POST_BIND,
BPF_CGROUP_INET6_POST_BIND,
AF_INET6,
SOCK_STREAM,
"::",
0,
SUCCESS,
},
};
static size_t probe_prog_length(const struct bpf_insn *fp)
{
size_t len;
for (len = MAX_INSNS - 1; len > 0; --len)
if (fp[len].code != 0 || fp[len].imm != 0)
break;
return len + 1;
}
static int load_sock_prog(const struct bpf_insn *prog,
enum bpf_attach_type attach_type)
{
struct bpf_load_program_attr attr;
memset(&attr, 0, sizeof(struct bpf_load_program_attr));
attr.prog_type = BPF_PROG_TYPE_CGROUP_SOCK;
attr.expected_attach_type = attach_type;
attr.insns = prog;
attr.insns_cnt = probe_prog_length(attr.insns);
attr.license = "GPL";
return bpf_load_program_xattr(&attr, bpf_log_buf, BPF_LOG_BUF_SIZE);
}
static int attach_sock_prog(int cgfd, int progfd,
enum bpf_attach_type attach_type)
{
return bpf_prog_attach(progfd, cgfd, attach_type, BPF_F_ALLOW_OVERRIDE);
}
static int bind_sock(int domain, int type, const char *ip, unsigned short port)
{
struct sockaddr_storage addr;
struct sockaddr_in6 *addr6;
struct sockaddr_in *addr4;
int sockfd = -1;
socklen_t len;
int err = 0;
sockfd = socket(domain, type, 0);
if (sockfd < 0)
goto err;
memset(&addr, 0, sizeof(addr));
if (domain == AF_INET) {
len = sizeof(struct sockaddr_in);
addr4 = (struct sockaddr_in *)&addr;
addr4->sin_family = domain;
addr4->sin_port = htons(port);
if (inet_pton(domain, ip, (void *)&addr4->sin_addr) != 1)
goto err;
} else if (domain == AF_INET6) {
len = sizeof(struct sockaddr_in6);
addr6 = (struct sockaddr_in6 *)&addr;
addr6->sin6_family = domain;
addr6->sin6_port = htons(port);
if (inet_pton(domain, ip, (void *)&addr6->sin6_addr) != 1)
goto err;
} else {
goto err;
}
if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1)
goto err;
goto out;
err:
err = -1;
out:
close(sockfd);
return err;
}
static int run_test_case(int cgfd, const struct sock_test *test)
{
int progfd = -1;
int err = 0;
printf("Test case: %s .. ", test->descr);
progfd = load_sock_prog(test->insns, test->expected_attach_type);
if (progfd < 0) {
if (test->result == LOAD_REJECT)
goto out;
else
goto err;
}
if (attach_sock_prog(cgfd, progfd, test->attach_type) == -1) {
if (test->result == ATTACH_REJECT)
goto out;
else
goto err;
}
if (bind_sock(test->domain, test->type, test->ip, test->port) == -1) {
/* sys_bind() may fail for different reasons, errno has to be
* checked to confirm that BPF program rejected it.
*/
if (test->result == BIND_REJECT && errno == EPERM)
goto out;
else
goto err;
}
if (test->result != SUCCESS)
goto err;
goto out;
err:
err = -1;
out:
/* Detaching w/o checking return code: best effort attempt. */
if (progfd != -1)
bpf_prog_detach(cgfd, test->attach_type);
close(progfd);
printf("[%s]\n", err ? "FAIL" : "PASS");
return err;
}
static int run_tests(int cgfd)
{
int passes = 0;
int fails = 0;
int i;
for (i = 0; i < ARRAY_SIZE(tests); ++i) {
if (run_test_case(cgfd, &tests[i]))
++fails;
else
++passes;
}
printf("Summary: %d PASSED, %d FAILED\n", passes, fails);
return fails ? -1 : 0;
}
int main(int argc, char **argv)
{
int cgfd = -1;
int err = 0;
if (setup_cgroup_environment())
goto err;
cgfd = create_and_get_cgroup(CG_PATH);
if (!cgfd)
goto err;
if (join_cgroup(CG_PATH))
goto err;
if (run_tests(cgfd))
goto err;
goto out;
err:
err = -1;
out:
close(cgfd);
cleanup_cgroup_environment();
return err;
}