linux/tools/testing/selftests/bpf/prog_tests/sock_post_bind.c

427 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/bpf.h>
#include <test_progs.h>
#include "cgroup_helpers.h"
#define TEST_NS "sock_post_bind"
static char bpf_log_buf[4096];
static struct sock_post_bind_test {
const char *descr;
/* BPF prog properties */
const struct bpf_insn insns[64];
enum bpf_attach_type attach_type;
enum bpf_attach_type expected_attach_type;
/* Socket properties */
int domain;
int type;
/* Endpoint to bind() to */
const char *ip;
unsigned short port;
unsigned short port_retry;
/* Expected test result */
enum {
ATTACH_REJECT,
BIND_REJECT,
SUCCESS,
RETRY_SUCCESS,
RETRY_REJECT
} result;
} tests[] = {
{
.descr = "attach type mismatch bind4 vs bind6",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
.attach_type = BPF_CGROUP_INET6_POST_BIND,
.result = ATTACH_REJECT,
},
{
.descr = "attach type mismatch bind6 vs bind4",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
.attach_type = BPF_CGROUP_INET4_POST_BIND,
.result = ATTACH_REJECT,
},
{
.descr = "attach type mismatch default vs bind4",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.expected_attach_type = 0,
.attach_type = BPF_CGROUP_INET4_POST_BIND,
.result = ATTACH_REJECT,
},
{
.descr = "attach type mismatch bind6 vs sock_create",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
.result = ATTACH_REJECT,
},
{
.descr = "bind4 reject all",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
.attach_type = BPF_CGROUP_INET4_POST_BIND,
.domain = AF_INET,
.type = SOCK_STREAM,
.ip = "0.0.0.0",
.result = BIND_REJECT,
},
{
.descr = "bind6 reject all",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
.attach_type = BPF_CGROUP_INET6_POST_BIND,
.domain = AF_INET6,
.type = SOCK_STREAM,
.ip = "::",
.result = BIND_REJECT,
},
{
.descr = "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,
__bpf_constant_ntohl(0x00000001), 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(),
},
.expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
.attach_type = BPF_CGROUP_INET6_POST_BIND,
.domain = AF_INET6,
.type = SOCK_STREAM,
.ip = "::1",
.port = 8193,
.result = BIND_REJECT,
},
{
.descr = "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,
__bpf_constant_ntohl(0x7F000001), 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(),
},
.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
.attach_type = BPF_CGROUP_INET4_POST_BIND,
.domain = AF_INET,
.type = SOCK_STREAM,
.ip = "127.0.0.1",
.port = 4098,
.result = SUCCESS,
},
{
.descr = "bind4 deny specific IP & port of TCP, and retry",
.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,
__bpf_constant_ntohl(0x7F000001), 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 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(),
},
.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
.attach_type = BPF_CGROUP_INET4_POST_BIND,
.domain = AF_INET,
.type = SOCK_STREAM,
.ip = "127.0.0.1",
.port = 4098,
.port_retry = 5000,
.result = RETRY_SUCCESS,
},
{
.descr = "bind4 deny specific IP & port of UDP, and retry",
.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,
__bpf_constant_ntohl(0x7F000001), 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 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(),
},
.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
.attach_type = BPF_CGROUP_INET4_POST_BIND,
.domain = AF_INET,
.type = SOCK_DGRAM,
.ip = "127.0.0.1",
.port = 4098,
.port_retry = 5000,
.result = RETRY_SUCCESS,
},
{
.descr = "bind6 deny specific IP & port, and retry",
.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,
__bpf_constant_ntohl(0x00000001), 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(),
},
.expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
.attach_type = BPF_CGROUP_INET6_POST_BIND,
.domain = AF_INET6,
.type = SOCK_STREAM,
.ip = "::1",
.port = 8193,
.port_retry = 9000,
.result = RETRY_SUCCESS,
},
{
.descr = "bind4 allow all",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
.attach_type = BPF_CGROUP_INET4_POST_BIND,
.domain = AF_INET,
.type = SOCK_STREAM,
.ip = "0.0.0.0",
.result = SUCCESS,
},
{
.descr = "bind6 allow all",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
.attach_type = BPF_CGROUP_INET6_POST_BIND,
.domain = AF_INET6,
.type = SOCK_STREAM,
.ip = "::",
.result = SUCCESS,
},
};
static int load_prog(const struct bpf_insn *insns,
enum bpf_attach_type expected_attach_type)
{
LIBBPF_OPTS(bpf_prog_load_opts, opts,
.expected_attach_type = expected_attach_type,
.log_level = 2,
.log_buf = bpf_log_buf,
.log_size = sizeof(bpf_log_buf),
);
int fd, insns_cnt = 0;
for (;
insns[insns_cnt].code != (BPF_JMP | BPF_EXIT);
insns_cnt++) {
}
insns_cnt++;
fd = bpf_prog_load(BPF_PROG_TYPE_CGROUP_SOCK, NULL, "GPL", insns,
insns_cnt, &opts);
if (fd < 0)
fprintf(stderr, "%s\n", bpf_log_buf);
return fd;
}
static int bind_sock(int domain, int type, const char *ip,
unsigned short port, unsigned short port_retry)
{
struct sockaddr_storage addr;
struct sockaddr_in6 *addr6;
struct sockaddr_in *addr4;
int sockfd = -1;
socklen_t len;
int res = SUCCESS;
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) {
/* sys_bind() may fail for different reasons, errno has to be
* checked to confirm that BPF program rejected it.
*/
if (errno != EPERM)
goto err;
if (port_retry)
goto retry;
res = BIND_REJECT;
goto out;
}
goto out;
retry:
if (domain == AF_INET)
addr4->sin_port = htons(port_retry);
else
addr6->sin6_port = htons(port_retry);
if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1) {
if (errno != EPERM)
goto err;
res = RETRY_REJECT;
} else {
res = RETRY_SUCCESS;
}
goto out;
err:
res = -1;
out:
close(sockfd);
return res;
}
static int run_test(int cgroup_fd, struct sock_post_bind_test *test)
{
int err, prog_fd, res, ret = 0;
prog_fd = load_prog(test->insns, test->expected_attach_type);
if (prog_fd < 0)
goto err;
err = bpf_prog_attach(prog_fd, cgroup_fd, test->attach_type, 0);
if (err < 0) {
if (test->result == ATTACH_REJECT)
goto out;
else
goto err;
}
res = bind_sock(test->domain, test->type, test->ip, test->port,
test->port_retry);
if (res > 0 && test->result == res)
goto out;
err:
ret = -1;
out:
/* Detaching w/o checking return code: best effort attempt. */
if (prog_fd != -1)
bpf_prog_detach(cgroup_fd, test->attach_type);
close(prog_fd);
return ret;
}
void test_sock_post_bind(void)
{
struct netns_obj *ns;
int cgroup_fd;
int i;
cgroup_fd = test__join_cgroup("/post_bind");
if (!ASSERT_OK_FD(cgroup_fd, "join_cgroup"))
return;
ns = netns_new(TEST_NS, true);
if (!ASSERT_OK_PTR(ns, "netns_new"))
goto cleanup;
for (i = 0; i < ARRAY_SIZE(tests); i++) {
if (!test__start_subtest(tests[i].descr))
continue;
ASSERT_OK(run_test(cgroup_fd, &tests[i]), tests[i].descr);
}
cleanup:
netns_free(ns);
close(cgroup_fd);
}