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// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 Facebook
#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <linux/filter.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include <bpf/bpf_endian.h>
#include "bpf_rlimit.h"
#include "bpf_util.h"
#include "cgroup_helpers.h"
#define CG_PATH "/foo"
#define MAX_INSNS 512
#define FIXUP_SYSCTL_VALUE 0
char bpf_log_buf[BPF_LOG_BUF_SIZE];
struct sysctl_test {
const char *descr;
size_t fixup_value_insn;
const char *prog_file;
enum bpf_attach_type attach_type;
const char *sysctl;
int open_flags;
const char *oldval;
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enum {
LOAD_REJECT,
ATTACH_REJECT,
OP_EPERM,
SUCCESS,
} result;
};
static struct sysctl_test tests[] = {
{
.descr = "sysctl wrong attach_type",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = 0,
.sysctl = "kernel/ostype",
.open_flags = O_RDONLY,
.result = ATTACH_REJECT,
},
{
.descr = "sysctl:read allow all",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "kernel/ostype",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
.descr = "sysctl:read deny all",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "kernel/ostype",
.open_flags = O_RDONLY,
.result = OP_EPERM,
},
{
.descr = "ctx:write sysctl:read read ok",
.insns = {
/* If (write) */
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1,
offsetof(struct bpf_sysctl, write)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 1, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "kernel/ostype",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
.descr = "ctx:write sysctl:write read ok",
.insns = {
/* If (write) */
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1,
offsetof(struct bpf_sysctl, write)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 1, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "kernel/domainname",
.open_flags = O_WRONLY,
.newval = "(none)", /* same as default, should fail anyway */
.result = OP_EPERM,
},
{
.descr = "ctx:write sysctl:write read ok narrow",
.insns = {
/* u64 w = (u16)write & 1; */
#if __BYTE_ORDER == __LITTLE_ENDIAN
BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_1,
offsetof(struct bpf_sysctl, write)),
#else
BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_1,
offsetof(struct bpf_sysctl, write) + 2),
#endif
BPF_ALU64_IMM(BPF_AND, BPF_REG_7, 1),
/* return 1 - w; */
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_7),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "kernel/domainname",
.open_flags = O_WRONLY,
.newval = "(none)", /* same as default, should fail anyway */
.result = OP_EPERM,
},
{
.descr = "ctx:write sysctl:read write reject",
.insns = {
/* write = X */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sysctl, write)),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "kernel/ostype",
.open_flags = O_RDONLY,
.result = LOAD_REJECT,
},
{
.descr = "ctx:file_pos sysctl:read read ok",
.insns = {
/* If (file_pos == X) */
BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1,
offsetof(struct bpf_sysctl, file_pos)),
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 3, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "kernel/ostype",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
.descr = "ctx:file_pos sysctl:read read ok narrow",
.insns = {
/* If (file_pos == X) */
#if __BYTE_ORDER == __LITTLE_ENDIAN
BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_1,
offsetof(struct bpf_sysctl, file_pos)),
#else
BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_1,
offsetof(struct bpf_sysctl, file_pos) + 3),
#endif
BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 4, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "kernel/ostype",
.open_flags = O_RDONLY,
.seek = 4,
.result = SUCCESS,
},
{
.descr = "ctx:file_pos sysctl:read write ok",
.insns = {
/* file_pos = X */
BPF_MOV64_IMM(BPF_REG_0, 2),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sysctl, file_pos)),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "kernel/ostype",
.open_flags = O_RDONLY,
.oldval = "nux\n",
.result = SUCCESS,
},
{
.descr = "sysctl_get_name sysctl_value:base ok",
.insns = {
/* sysctl_get_name arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_name arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 8),
/* sysctl_get_name arg4 (flags) */
BPF_MOV64_IMM(BPF_REG_4, BPF_F_SYSCTL_BASE_NAME),
/* sysctl_get_name(ctx, buf, buf_len, flags) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_name),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, sizeof("tcp_mem") - 1, 6),
/* buf == "tcp_mem\0") */
BPF_LD_IMM64(BPF_REG_8,
bpf_be64_to_cpu(0x7463705f6d656d00ULL)),
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BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/tcp_mem",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
.descr = "sysctl_get_name sysctl_value:base E2BIG truncated",
.insns = {
/* sysctl_get_name arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_name arg3 (buf_len) too small */
BPF_MOV64_IMM(BPF_REG_3, 7),
/* sysctl_get_name arg4 (flags) */
BPF_MOV64_IMM(BPF_REG_4, BPF_F_SYSCTL_BASE_NAME),
/* sysctl_get_name(ctx, buf, buf_len, flags) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_name),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -E2BIG, 6),
/* buf[0:7] == "tcp_me\0") */
BPF_LD_IMM64(BPF_REG_8,
bpf_be64_to_cpu(0x7463705f6d650000ULL)),
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BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/tcp_mem",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
.descr = "sysctl_get_name sysctl:full ok",
.insns = {
/* sysctl_get_name arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -24),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 8),
BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 16),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_name arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 17),
/* sysctl_get_name arg4 (flags) */
BPF_MOV64_IMM(BPF_REG_4, 0),
/* sysctl_get_name(ctx, buf, buf_len, flags) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_name),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 16, 14),
/* buf[0:8] == "net/ipv4" && */
BPF_LD_IMM64(BPF_REG_8,
bpf_be64_to_cpu(0x6e65742f69707634ULL)),
BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 10),
/* buf[8:16] == "/tcp_mem" && */
BPF_LD_IMM64(BPF_REG_8,
bpf_be64_to_cpu(0x2f7463705f6d656dULL)),
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BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 8),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 6),
/* buf[16:24] == "\0") */
BPF_LD_IMM64(BPF_REG_8, 0x0ULL),
BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 16),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/tcp_mem",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
.descr = "sysctl_get_name sysctl:full E2BIG truncated",
.insns = {
/* sysctl_get_name arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -16),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 8),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_name arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 16),
/* sysctl_get_name arg4 (flags) */
BPF_MOV64_IMM(BPF_REG_4, 0),
/* sysctl_get_name(ctx, buf, buf_len, flags) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_name),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -E2BIG, 10),
/* buf[0:8] == "net/ipv4" && */
BPF_LD_IMM64(BPF_REG_8,
bpf_be64_to_cpu(0x6e65742f69707634ULL)),
BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 6),
/* buf[8:16] == "/tcp_me\0") */
BPF_LD_IMM64(BPF_REG_8,
bpf_be64_to_cpu(0x2f7463705f6d6500ULL)),
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BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 8),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/tcp_mem",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
.descr = "sysctl_get_name sysctl:full E2BIG truncated small",
.insns = {
/* sysctl_get_name arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_name arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 7),
/* sysctl_get_name arg4 (flags) */
BPF_MOV64_IMM(BPF_REG_4, 0),
/* sysctl_get_name(ctx, buf, buf_len, flags) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_name),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -E2BIG, 6),
/* buf[0:8] == "net/ip\0") */
BPF_LD_IMM64(BPF_REG_8,
bpf_be64_to_cpu(0x6e65742f69700000ULL)),
BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/tcp_mem",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
.descr = "sysctl_get_current_value sysctl:read ok, gt",
.insns = {
/* sysctl_get_current_value arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_current_value arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 8),
/* sysctl_get_current_value(ctx, buf, buf_len) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_current_value),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 6, 6),
/* buf[0:6] == "Linux\n\0") */
BPF_LD_IMM64(BPF_REG_8,
bpf_be64_to_cpu(0x4c696e75780a0000ULL)),
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BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "kernel/ostype",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
.descr = "sysctl_get_current_value sysctl:read ok, eq",
.insns = {
/* sysctl_get_current_value arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_B, BPF_REG_7, BPF_REG_0, 7),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_current_value arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 7),
/* sysctl_get_current_value(ctx, buf, buf_len) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_current_value),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 6, 6),
/* buf[0:6] == "Linux\n\0") */
BPF_LD_IMM64(BPF_REG_8,
bpf_be64_to_cpu(0x4c696e75780a0000ULL)),
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BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "kernel/ostype",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
.descr = "sysctl_get_current_value sysctl:read E2BIG truncated",
.insns = {
/* sysctl_get_current_value arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_H, BPF_REG_7, BPF_REG_0, 6),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_current_value arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 6),
/* sysctl_get_current_value(ctx, buf, buf_len) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_current_value),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -E2BIG, 6),
/* buf[0:6] == "Linux\0") */
BPF_LD_IMM64(BPF_REG_8,
bpf_be64_to_cpu(0x4c696e7578000000ULL)),
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BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "kernel/ostype",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
.descr = "sysctl_get_current_value sysctl:read EINVAL",
.insns = {
/* sysctl_get_current_value arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_current_value arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 8),
/* sysctl_get_current_value(ctx, buf, buf_len) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_current_value),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -EINVAL, 4),
/* buf[0:8] is NUL-filled) */
BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_9, 0, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv6/conf/lo/stable_secret", /* -EIO */
.open_flags = O_RDONLY,
.result = OP_EPERM,
},
{
.descr = "sysctl_get_current_value sysctl:write ok",
.fixup_value_insn = 6,
.insns = {
/* sysctl_get_current_value arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_current_value arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 8),
/* sysctl_get_current_value(ctx, buf, buf_len) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_current_value),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 4, 6),
/* buf[0:4] == expected) */
BPF_LD_IMM64(BPF_REG_8, FIXUP_SYSCTL_VALUE),
BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/route/mtu_expires",
.open_flags = O_WRONLY,
.newval = "600", /* same as default, should fail anyway */
.result = OP_EPERM,
},
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{
.descr = "sysctl_get_new_value sysctl:read EINVAL",
.insns = {
/* sysctl_get_new_value arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_new_value arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 8),
/* sysctl_get_new_value(ctx, buf, buf_len) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_new_value),
/* if (ret == expected) */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -EINVAL, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/tcp_mem",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
.descr = "sysctl_get_new_value sysctl:write ok",
.insns = {
/* sysctl_get_new_value arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_new_value arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 4),
/* sysctl_get_new_value(ctx, buf, buf_len) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_new_value),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 3, 4),
/* buf[0:4] == "606\0") */
BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_9,
bpf_ntohl(0x36303600), 2),
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/* 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/route/mtu_expires",
.open_flags = O_WRONLY,
.newval = "606",
.result = OP_EPERM,
},
{
.descr = "sysctl_get_new_value sysctl:write ok long",
.insns = {
/* sysctl_get_new_value arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -24),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_new_value arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 24),
/* sysctl_get_new_value(ctx, buf, buf_len) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_new_value),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 23, 14),
/* buf[0:8] == "3000000 " && */
BPF_LD_IMM64(BPF_REG_8,
bpf_be64_to_cpu(0x3330303030303020ULL)),
BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 10),
/* buf[8:16] == "4000000 " && */
BPF_LD_IMM64(BPF_REG_8,
bpf_be64_to_cpu(0x3430303030303020ULL)),
BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 8),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 6),
/* buf[16:24] == "6000000\0") */
BPF_LD_IMM64(BPF_REG_8,
bpf_be64_to_cpu(0x3630303030303000ULL)),
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BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 16),
BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/tcp_mem",
.open_flags = O_WRONLY,
.newval = "3000000 4000000 6000000",
.result = OP_EPERM,
},
{
.descr = "sysctl_get_new_value sysctl:write E2BIG",
.insns = {
/* sysctl_get_new_value arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_B, BPF_REG_7, BPF_REG_0, 3),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_get_new_value arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 3),
/* sysctl_get_new_value(ctx, buf, buf_len) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_get_new_value),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -E2BIG, 4),
/* buf[0:3] == "60\0") */
BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_9,
bpf_ntohl(0x36300000), 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/route/mtu_expires",
.open_flags = O_WRONLY,
.newval = "606",
.result = OP_EPERM,
},
{
.descr = "sysctl_set_new_value sysctl:read EINVAL",
.insns = {
/* sysctl_set_new_value arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_IMM(BPF_REG_0,
bpf_ntohl(0x36303000)),
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BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_set_new_value arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 3),
/* sysctl_set_new_value(ctx, buf, buf_len) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_set_new_value),
/* if (ret == expected) */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -EINVAL, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/route/mtu_expires",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
.descr = "sysctl_set_new_value sysctl:write ok",
.fixup_value_insn = 2,
.insns = {
/* sysctl_set_new_value arg2 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_LD_IMM64(BPF_REG_0, FIXUP_SYSCTL_VALUE),
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BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
/* sysctl_set_new_value arg3 (buf_len) */
BPF_MOV64_IMM(BPF_REG_3, 3),
/* sysctl_set_new_value(ctx, buf, buf_len) */
BPF_EMIT_CALL(BPF_FUNC_sysctl_set_new_value),
/* if (ret == expected) */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/route/mtu_expires",
.open_flags = O_WRONLY,
.newval = "606",
.result = SUCCESS,
},
{
"bpf_strtoul one number string",
.insns = {
/* arg1 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_IMM(BPF_REG_0,
bpf_ntohl(0x36303000)),
BPF_STX_MEM(BPF_W, BPF_REG_7, BPF_REG_0, 0),
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BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
/* arg2 (buf_len) */
BPF_MOV64_IMM(BPF_REG_2, 4),
/* arg3 (flags) */
BPF_MOV64_IMM(BPF_REG_3, 0),
/* arg4 (res) */
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_4, BPF_REG_7),
BPF_EMIT_CALL(BPF_FUNC_strtoul),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 3, 4),
/* res == expected) */
BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_9, 600, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/route/mtu_expires",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
"bpf_strtoul multi number string",
.insns = {
/* arg1 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
/* "600 602\0" */
BPF_LD_IMM64(BPF_REG_0,
bpf_be64_to_cpu(0x3630302036303200ULL)),
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BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
/* arg2 (buf_len) */
BPF_MOV64_IMM(BPF_REG_2, 8),
/* arg3 (flags) */
BPF_MOV64_IMM(BPF_REG_3, 0),
/* arg4 (res) */
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_4, BPF_REG_7),
BPF_EMIT_CALL(BPF_FUNC_strtoul),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 3, 18),
/* res == expected) */
BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_9, 600, 16),
/* arg1 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_ALU64_REG(BPF_ADD, BPF_REG_7, BPF_REG_0),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
/* arg2 (buf_len) */
BPF_MOV64_IMM(BPF_REG_2, 8),
BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_0),
/* arg3 (flags) */
BPF_MOV64_IMM(BPF_REG_3, 0),
/* arg4 (res) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -16),
BPF_MOV64_REG(BPF_REG_4, BPF_REG_7),
BPF_EMIT_CALL(BPF_FUNC_strtoul),
/* if (ret == expected && */
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 4, 4),
/* res == expected) */
BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_9, 602, 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(),
},
.attach_type = BPF_CGROUP_SYSCTL,
.sysctl = "net/ipv4/tcp_mem",
.open_flags = O_RDONLY,
.result = SUCCESS,
},
{
"bpf_strtoul buf_len = 0, reject",
.insns = {
/* arg1 (buf) */
BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
BPF_MOV64_IMM(BPF_REG_0,
bpf_ntohl(0x36303000)),