selftests/bpf: migrate cgroup sock create test for setting iface/mark/prio

This patch migrates the old test for cgroup BPF that sets
sk_bound_dev_if, mark, and priority when AF_INET{6} sockets are created.
The most closely related tests under selftests are 'test_sock' and
'sockopt'. However, these existing tests serve different purposes.
'test_sock' focuses mainly on verifying the socket binding process,
while 'sockopt' concentrates on testing the behavior of getsockopt and
setsockopt operations for various socket options.

Neither of these existing tests directly covers the ability of cgroup
BPF to set socket attributes such as sk_bound_dev_if, mark, and priority
during socket creation. To address this gap, this patch introduces a
migration of the old cgroup socket attribute test, now included as the
'sock_create' test in selftests/bpf. This ensures that the ability to
configure these attributes during socket creation is properly tested.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20241011044847.51584-2-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Daniel T. Lee 2024-10-11 04:48:44 +00:00 committed by Alexei Starovoitov
parent ba4fb3b3f7
commit ec6c4be073
4 changed files with 256 additions and 435 deletions

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@ -27,7 +27,6 @@ tprogs-y += map_perf_test
tprogs-y += test_overhead
tprogs-y += test_cgrp2_array_pin
tprogs-y += test_cgrp2_attach
tprogs-y += test_cgrp2_sock
tprogs-y += test_cgrp2_sock2
tprogs-y += xdp_router_ipv4
tprogs-y += test_current_task_under_cgroup
@ -76,7 +75,6 @@ map_perf_test-objs := map_perf_test_user.o
test_overhead-objs := test_overhead_user.o
test_cgrp2_array_pin-objs := test_cgrp2_array_pin.o
test_cgrp2_attach-objs := test_cgrp2_attach.o
test_cgrp2_sock-objs := test_cgrp2_sock.o
test_cgrp2_sock2-objs := test_cgrp2_sock2.o
test_current_task_under_cgroup-objs := $(CGROUP_HELPERS) \
test_current_task_under_cgroup_user.o

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@ -1,296 +0,0 @@
/* eBPF example program:
*
* - Loads eBPF program
*
* The eBPF program sets the sk_bound_dev_if index in new AF_INET{6}
* sockets opened by processes in the cgroup.
*
* - Attaches the new program to a cgroup using BPF_PROG_ATTACH
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <unistd.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <inttypes.h>
#include <linux/bpf.h>
#include <bpf/bpf.h>
#include "bpf_insn.h"
char bpf_log_buf[BPF_LOG_BUF_SIZE];
static int prog_load(__u32 idx, __u32 mark, __u32 prio)
{
/* save pointer to context */
struct bpf_insn prog_start[] = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
};
struct bpf_insn prog_end[] = {
BPF_MOV64_IMM(BPF_REG_0, 1), /* r0 = verdict */
BPF_EXIT_INSN(),
};
/* set sk_bound_dev_if on socket */
struct bpf_insn prog_dev[] = {
BPF_MOV64_IMM(BPF_REG_3, idx),
BPF_MOV64_IMM(BPF_REG_2, offsetof(struct bpf_sock, bound_dev_if)),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3, offsetof(struct bpf_sock, bound_dev_if)),
};
/* set mark on socket */
struct bpf_insn prog_mark[] = {
/* get uid of process */
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_current_uid_gid),
BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0xffffffff),
/* if uid is 0, use given mark, else use the uid as the mark */
BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
BPF_MOV64_IMM(BPF_REG_3, mark),
/* set the mark on the new socket */
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_MOV64_IMM(BPF_REG_2, offsetof(struct bpf_sock, mark)),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3, offsetof(struct bpf_sock, mark)),
};
/* set priority on socket */
struct bpf_insn prog_prio[] = {
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_MOV64_IMM(BPF_REG_3, prio),
BPF_MOV64_IMM(BPF_REG_2, offsetof(struct bpf_sock, priority)),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3, offsetof(struct bpf_sock, priority)),
};
LIBBPF_OPTS(bpf_prog_load_opts, opts,
.log_buf = bpf_log_buf,
.log_size = BPF_LOG_BUF_SIZE,
);
struct bpf_insn *prog;
size_t insns_cnt;
void *p;
int ret;
insns_cnt = sizeof(prog_start) + sizeof(prog_end);
if (idx)
insns_cnt += sizeof(prog_dev);
if (mark)
insns_cnt += sizeof(prog_mark);
if (prio)
insns_cnt += sizeof(prog_prio);
p = prog = malloc(insns_cnt);
if (!prog) {
fprintf(stderr, "Failed to allocate memory for instructions\n");
return EXIT_FAILURE;
}
memcpy(p, prog_start, sizeof(prog_start));
p += sizeof(prog_start);
if (idx) {
memcpy(p, prog_dev, sizeof(prog_dev));
p += sizeof(prog_dev);
}
if (mark) {
memcpy(p, prog_mark, sizeof(prog_mark));
p += sizeof(prog_mark);
}
if (prio) {
memcpy(p, prog_prio, sizeof(prog_prio));
p += sizeof(prog_prio);
}
memcpy(p, prog_end, sizeof(prog_end));
p += sizeof(prog_end);
insns_cnt /= sizeof(struct bpf_insn);
ret = bpf_prog_load(BPF_PROG_TYPE_CGROUP_SOCK, NULL, "GPL",
prog, insns_cnt, &opts);
free(prog);
return ret;
}
static int get_bind_to_device(int sd, char *name, size_t len)
{
socklen_t optlen = len;
int rc;
name[0] = '\0';
rc = getsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, name, &optlen);
if (rc < 0)
perror("setsockopt(SO_BINDTODEVICE)");
return rc;
}
static unsigned int get_somark(int sd)
{
unsigned int mark = 0;
socklen_t optlen = sizeof(mark);
int rc;
rc = getsockopt(sd, SOL_SOCKET, SO_MARK, &mark, &optlen);
if (rc < 0)
perror("getsockopt(SO_MARK)");
return mark;
}
static unsigned int get_priority(int sd)
{
unsigned int prio = 0;
socklen_t optlen = sizeof(prio);
int rc;
rc = getsockopt(sd, SOL_SOCKET, SO_PRIORITY, &prio, &optlen);
if (rc < 0)
perror("getsockopt(SO_PRIORITY)");
return prio;
}
static int show_sockopts(int family)
{
unsigned int mark, prio;
char name[16];
int sd;
sd = socket(family, SOCK_DGRAM, 17);
if (sd < 0) {
perror("socket");
return 1;
}
if (get_bind_to_device(sd, name, sizeof(name)) < 0) {
close(sd);
return 1;
}
mark = get_somark(sd);
prio = get_priority(sd);
close(sd);
printf("sd %d: dev %s, mark %u, priority %u\n", sd, name, mark, prio);
return 0;
}
static int usage(const char *argv0)
{
printf("Usage:\n");
printf(" Attach a program\n");
printf(" %s -b bind-to-dev -m mark -p prio cg-path\n", argv0);
printf("\n");
printf(" Detach a program\n");
printf(" %s -d cg-path\n", argv0);
printf("\n");
printf(" Show inherited socket settings (mark, priority, and device)\n");
printf(" %s [-6]\n", argv0);
return EXIT_FAILURE;
}
int main(int argc, char **argv)
{
__u32 idx = 0, mark = 0, prio = 0;
const char *cgrp_path = NULL;
int cg_fd, prog_fd, ret;
int family = PF_INET;
int do_attach = 1;
int rc;
while ((rc = getopt(argc, argv, "db:m:p:6")) != -1) {
switch (rc) {
case 'd':
do_attach = 0;
break;
case 'b':
idx = if_nametoindex(optarg);
if (!idx) {
idx = strtoumax(optarg, NULL, 0);
if (!idx) {
printf("Invalid device name\n");
return EXIT_FAILURE;
}
}
break;
case 'm':
mark = strtoumax(optarg, NULL, 0);
break;
case 'p':
prio = strtoumax(optarg, NULL, 0);
break;
case '6':
family = PF_INET6;
break;
default:
return usage(argv[0]);
}
}
if (optind == argc)
return show_sockopts(family);
cgrp_path = argv[optind];
if (!cgrp_path) {
fprintf(stderr, "cgroup path not given\n");
return EXIT_FAILURE;
}
if (do_attach && !idx && !mark && !prio) {
fprintf(stderr,
"One of device, mark or priority must be given\n");
return EXIT_FAILURE;
}
cg_fd = open(cgrp_path, O_DIRECTORY | O_RDONLY);
if (cg_fd < 0) {
printf("Failed to open cgroup path: '%s'\n", strerror(errno));
return EXIT_FAILURE;
}
if (do_attach) {
prog_fd = prog_load(idx, mark, prio);
if (prog_fd < 0) {
printf("Failed to load prog: '%s'\n", strerror(errno));
printf("Output from kernel verifier:\n%s\n-------\n",
bpf_log_buf);
return EXIT_FAILURE;
}
ret = bpf_prog_attach(prog_fd, cg_fd,
BPF_CGROUP_INET_SOCK_CREATE, 0);
if (ret < 0) {
printf("Failed to attach prog to cgroup: '%s'\n",
strerror(errno));
return EXIT_FAILURE;
}
} else {
ret = bpf_prog_detach(cg_fd, BPF_CGROUP_INET_SOCK_CREATE);
if (ret < 0) {
printf("Failed to detach prog from cgroup: '%s'\n",
strerror(errno));
return EXIT_FAILURE;
}
}
close(cg_fd);
return EXIT_SUCCESS;
}

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@ -1,137 +0,0 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# Test various socket options that can be set by attaching programs to cgroups.
MY_DIR=$(dirname $0)
TEST=$MY_DIR/test_cgrp2_sock
CGRP_MNT="/tmp/cgroupv2-test_cgrp2_sock"
################################################################################
#
print_result()
{
local rc=$1
local status=" OK "
[ $rc -ne 0 ] && status="FAIL"
printf "%-50s [%4s]\n" "$2" "$status"
}
check_sock()
{
out=$($TEST)
echo $out | grep -q "$1"
if [ $? -ne 0 ]; then
print_result 1 "IPv4: $2"
echo " expected: $1"
echo " have: $out"
rc=1
else
print_result 0 "IPv4: $2"
fi
}
check_sock6()
{
out=$($TEST -6)
echo $out | grep -q "$1"
if [ $? -ne 0 ]; then
print_result 1 "IPv6: $2"
echo " expected: $1"
echo " have: $out"
rc=1
else
print_result 0 "IPv6: $2"
fi
}
################################################################################
#
cleanup()
{
echo $$ >> ${CGRP_MNT}/cgroup.procs
rmdir ${CGRP_MNT}/sockopts
}
cleanup_and_exit()
{
local rc=$1
local msg="$2"
[ -n "$msg" ] && echo "ERROR: $msg"
$TEST -d ${CGRP_MNT}/sockopts
ip li del cgrp2_sock
umount ${CGRP_MNT}
exit $rc
}
################################################################################
# main
rc=0
ip li add cgrp2_sock type dummy 2>/dev/null
set -e
mkdir -p ${CGRP_MNT}
mount -t cgroup2 none ${CGRP_MNT}
set +e
# make sure we have a known start point
cleanup 2>/dev/null
mkdir -p ${CGRP_MNT}/sockopts
[ $? -ne 0 ] && cleanup_and_exit 1 "Failed to create cgroup hierarchy"
# set pid into cgroup
echo $$ > ${CGRP_MNT}/sockopts/cgroup.procs
# no bpf program attached, so socket should show no settings
check_sock "dev , mark 0, priority 0" "No programs attached"
check_sock6 "dev , mark 0, priority 0" "No programs attached"
# verify device is set
#
$TEST -b cgrp2_sock ${CGRP_MNT}/sockopts
if [ $? -ne 0 ]; then
cleanup_and_exit 1 "Failed to install program to set device"
fi
check_sock "dev cgrp2_sock, mark 0, priority 0" "Device set"
check_sock6 "dev cgrp2_sock, mark 0, priority 0" "Device set"
# verify mark is set
#
$TEST -m 666 ${CGRP_MNT}/sockopts
if [ $? -ne 0 ]; then
cleanup_and_exit 1 "Failed to install program to set mark"
fi
check_sock "dev , mark 666, priority 0" "Mark set"
check_sock6 "dev , mark 666, priority 0" "Mark set"
# verify priority is set
#
$TEST -p 123 ${CGRP_MNT}/sockopts
if [ $? -ne 0 ]; then
cleanup_and_exit 1 "Failed to install program to set priority"
fi
check_sock "dev , mark 0, priority 123" "Priority set"
check_sock6 "dev , mark 0, priority 123" "Priority set"
# all 3 at once
#
$TEST -b cgrp2_sock -m 666 -p 123 ${CGRP_MNT}/sockopts
if [ $? -ne 0 ]; then
cleanup_and_exit 1 "Failed to install program to set device, mark and priority"
fi
check_sock "dev cgrp2_sock, mark 666, priority 123" "Priority set"
check_sock6 "dev cgrp2_sock, mark 666, priority 123" "Priority set"
cleanup_and_exit $rc

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@ -0,0 +1,256 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/bpf.h>
#include <test_progs.h>
#include "cgroup_helpers.h"
static char bpf_log_buf[4096];
static bool verbose;
static struct sock_create_test {
const char *descr;
const struct bpf_insn insns[64];
enum bpf_attach_type attach_type;
enum bpf_attach_type expected_attach_type;
int domain;
int type;
int optname;
int optval;
} tests[] = {
{
.descr = "AF_INET set priority",
.insns = {
/* r3 = 123 (priority) */
BPF_MOV64_IMM(BPF_REG_3, 123),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
offsetof(struct bpf_sock, priority)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
.domain = AF_INET,
.type = SOCK_DGRAM,
.optname = SO_PRIORITY,
.optval = 123,
},
{
.descr = "AF_INET6 set priority",
.insns = {
/* r3 = 123 (priority) */
BPF_MOV64_IMM(BPF_REG_3, 123),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
offsetof(struct bpf_sock, priority)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
.domain = AF_INET6,
.type = SOCK_DGRAM,
.optname = SO_PRIORITY,
.optval = 123,
},
{
.descr = "AF_INET set mark",
.insns = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
/* get uid of process */
BPF_EMIT_CALL(BPF_FUNC_get_current_uid_gid),
BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0xffffffff),
/* if uid is 0, use given mark(666), else use uid as the mark */
BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
BPF_MOV64_IMM(BPF_REG_3, 666),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
offsetof(struct bpf_sock, mark)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
.domain = AF_INET,
.type = SOCK_DGRAM,
.optname = SO_MARK,
.optval = 666,
},
{
.descr = "AF_INET6 set mark",
.insns = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
/* get uid of process */
BPF_EMIT_CALL(BPF_FUNC_get_current_uid_gid),
BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0xffffffff),
/* if uid is 0, use given mark(666), else use uid as the mark */
BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
BPF_MOV64_IMM(BPF_REG_3, 666),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
offsetof(struct bpf_sock, mark)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
.domain = AF_INET6,
.type = SOCK_DGRAM,
.optname = SO_MARK,
.optval = 666,
},
{
.descr = "AF_INET bound to iface",
.insns = {
/* r3 = 1 (lo interface) */
BPF_MOV64_IMM(BPF_REG_3, 1),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
offsetof(struct bpf_sock, bound_dev_if)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
.domain = AF_INET,
.type = SOCK_DGRAM,
.optname = SO_BINDTOIFINDEX,
.optval = 1,
},
{
.descr = "AF_INET6 bound to iface",
.insns = {
/* r3 = 1 (lo interface) */
BPF_MOV64_IMM(BPF_REG_3, 1),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
offsetof(struct bpf_sock, bound_dev_if)),
/* return 1 */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
.domain = AF_INET6,
.type = SOCK_DGRAM,
.optname = SO_BINDTOIFINDEX,
.optval = 1,
},
};
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 (verbose && fd < 0)
fprintf(stderr, "%s\n", bpf_log_buf);
return fd;
}
static int run_test(int cgroup_fd, struct sock_create_test *test)
{
int sock_fd, err, prog_fd, optval, ret = -1;
socklen_t optlen = sizeof(optval);
prog_fd = load_prog(test->insns, test->expected_attach_type);
if (prog_fd < 0) {
log_err("Failed to load BPF program");
return -1;
}
err = bpf_prog_attach(prog_fd, cgroup_fd, test->attach_type, 0);
if (err < 0) {
log_err("Failed to attach BPF program");
goto close_prog_fd;
}
sock_fd = socket(test->domain, test->type, 0);
if (sock_fd < 0) {
log_err("Failed to create socket");
goto detach_prog;
}
err = getsockopt(sock_fd, SOL_SOCKET, test->optname, &optval, &optlen);
if (err) {
log_err("Failed to call getsockopt");
goto cleanup;
}
if (optval != test->optval) {
errno = 0;
log_err("getsockopt returned unexpected optval");
goto cleanup;
}
ret = 0;
cleanup:
close(sock_fd);
detach_prog:
bpf_prog_detach2(prog_fd, cgroup_fd, test->attach_type);
close_prog_fd:
close(prog_fd);
return ret;
}
void test_sock_create(void)
{
int cgroup_fd, i;
cgroup_fd = test__join_cgroup("/sock_create");
if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup"))
return;
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);
}
close(cgroup_fd);
}