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-rw-r--r--tools/testing/selftests/bpf/test_sysctl.c1567
1 files changed, 1567 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/test_sysctl.c b/tools/testing/selftests/bpf/test_sysctl.c
new file mode 100644
index 000000000000..a3bebd7c68dd
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_sysctl.c
@@ -0,0 +1,1567 @@
+// 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_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;
+ struct bpf_insn insns[MAX_INSNS];
+ const char *prog_file;
+ enum bpf_attach_type attach_type;
+ const char *sysctl;
+ int open_flags;
+ const char *newval;
+ const char *oldval;
+ 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_B, 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: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, 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 = "kernel/ostype",
+ .open_flags = O_RDONLY,
+ .result = SUCCESS,
+ },
+ {
+ .descr = "ctx:file_pos sysctl:read read ok narrow",
+ .insns = {
+ /* If (file_pos == X) */
+ BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_1,
+ offsetof(struct bpf_sysctl, file_pos)),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 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 = "kernel/ostype",
+ .open_flags = O_RDONLY,
+ .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, 0x006d656d5f706374ULL),
+ 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, 0x00656d5f706374ULL),
+ 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, 0x347670692f74656eULL),
+ 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, 0x6d656d5f7063742fULL),
+ 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, 0x347670692f74656eULL),
+ 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, 0x00656d5f7063742fULL),
+ 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, 0x000070692f74656eULL),
+ 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, 0x000a78756e694cULL),
+ 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, 0x000a78756e694cULL),
+ 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, 0x000078756e694cULL),
+ 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,
+ },
+ {
+ .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, 0x00363036, 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_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, 0x2030303030303033ULL),
+ 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, 0x2030303030303034ULL),
+ 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, 0x0030303030303036ULL),
+ 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, 0x003036, 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, 0x00303036),
+ 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_MOV64_IMM(BPF_REG_0, FIXUP_SYSCTL_VALUE),
+ 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, 0x00303036),
+ 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, 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, 0x0032303620303036ULL),
+ 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, 0x00303036),
+ 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, 0),
+
+ /* 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),
+
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SYSCTL,
+ .sysctl = "net/ipv4/route/mtu_expires",
+ .open_flags = O_RDONLY,
+ .result = LOAD_REJECT,
+ },
+ {
+ "bpf_strtoul supported base, ok",
+ .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, 0x00373730),
+ 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, 4),
+
+ /* arg3 (flags) */
+ BPF_MOV64_IMM(BPF_REG_3, 8),
+
+ /* 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, 63, 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 unsupported base, EINVAL",
+ .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, 0x00303036),
+ 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, 4),
+
+ /* arg3 (flags) */
+ BPF_MOV64_IMM(BPF_REG_3, 3),
+
+ /* 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, -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,
+ },
+ {
+ "bpf_strtoul buf with spaces only, EINVAL",
+ .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, 0x090a0c0d),
+ 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, 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, -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,
+ },
+ {
+ "bpf_strtoul negative number, EINVAL",
+ .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, 0x00362d0a), /* " -6\0" */
+ 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, 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, -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,
+ },
+ {
+ "bpf_strtol negative number, ok",
+ .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, 0x00362d0a), /* " -6\0" */
+ 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, 4),
+
+ /* arg3 (flags) */
+ BPF_MOV64_IMM(BPF_REG_3, 10),
+
+ /* 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_strtol),
+
+ /* 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, -6, 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_strtol hex number, ok",
+ .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, 0x65667830), /* "0xfe" */
+ 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, 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_strtol),
+
+ /* 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, 254, 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_strtol max long",
+ .insns = {
+ /* arg1 (buf) 9223372036854775807 */
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -24),
+ BPF_LD_IMM64(BPF_REG_0, 0x3032373333323239ULL),
+ BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
+ BPF_LD_IMM64(BPF_REG_0, 0x3537373435383633ULL),
+ BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 8),
+ BPF_LD_IMM64(BPF_REG_0, 0x0000000000373038ULL),
+ BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 16),
+
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
+
+ /* arg2 (buf_len) */
+ BPF_MOV64_IMM(BPF_REG_2, 19),
+
+ /* 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_strtol),
+
+ /* if (ret == expected && */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 19, 6),
+ /* res == expected) */
+ BPF_LD_IMM64(BPF_REG_8, 0x7fffffffffffffffULL),
+ 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/route/mtu_expires",
+ .open_flags = O_RDONLY,
+ .result = SUCCESS,
+ },
+ {
+ "bpf_strtol overflow, ERANGE",
+ .insns = {
+ /* arg1 (buf) 9223372036854775808 */
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -24),
+ BPF_LD_IMM64(BPF_REG_0, 0x3032373333323239ULL),
+ BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
+ BPF_LD_IMM64(BPF_REG_0, 0x3537373435383633ULL),
+ BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 8),
+ BPF_LD_IMM64(BPF_REG_0, 0x0000000000383038ULL),
+ BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 16),
+
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
+
+ /* arg2 (buf_len) */
+ BPF_MOV64_IMM(BPF_REG_2, 19),
+
+ /* 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_strtol),
+
+ /* if (ret == expected) */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -ERANGE, 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,
+ },
+ {
+ "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)
+{
+ 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 fixup_sysctl_value(const char *buf, size_t buf_len,
+ struct bpf_insn *prog, size_t insn_num)
+{
+ uint32_t value_num = 0;
+ uint8_t c, i;
+
+ if (buf_len > sizeof(value_num)) {
+ log_err("Value is too big (%zd) to use in fixup", buf_len);
+ return -1;
+ }
+
+ for (i = 0; i < buf_len; ++i) {
+ c = buf[i];
+ value_num |= (c << i * 8);
+ }
+
+ prog[insn_num].imm = value_num;
+
+ return 0;
+}
+
+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;
+ int ret;
+
+ memset(&attr, 0, sizeof(struct bpf_load_program_attr));
+ attr.prog_type = BPF_PROG_TYPE_CGROUP_SYSCTL;
+ attr.insns = prog;
+ attr.insns_cnt = probe_prog_length(attr.insns);
+ attr.license = "GPL";
+
+ if (test->fixup_value_insn) {
+ char buf[128];
+ ssize_t len;
+ int fd;
+
+ fd = open(sysctl_path, O_RDONLY | O_CLOEXEC);
+ if (fd < 0) {
+ log_err("open(%s) failed", sysctl_path);
+ return -1;
+ }
+ len = read(fd, buf, sizeof(buf));
+ if (len == -1) {
+ log_err("read(%s) failed", sysctl_path);
+ close(fd);
+ return -1;
+ }
+ close(fd);
+ if (fixup_sysctl_value(buf, len, prog, test->fixup_value_insn))
+ return -1;
+ }
+
+ ret = bpf_load_program_xattr(&attr, bpf_log_buf, BPF_LOG_BUF_SIZE);
+ if (ret < 0 && test->result != LOAD_REJECT) {
+ log_err(">>> Loading program error.\n"
+ ">>> Verifier output:\n%s\n-------\n", bpf_log_buf);
+ }
+
+ 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)
+{
+ int err = 0;
+ int fd;
+
+ fd = open(sysctl_path, test->open_flags | O_CLOEXEC);
+ if (fd < 0)
+ return fd;
+
+ if (test->open_flags == O_RDONLY) {
+ char buf[128];
+
+ if (read(fd, buf, sizeof(buf)) == -1)
+ goto err;
+ if (test->oldval &&
+ strncmp(buf, test->oldval, strlen(test->oldval))) {
+ log_err("Read value %s != %s", buf, test->oldval);
+ goto err;
+ }
+ } else if (test->open_flags == O_WRONLY) {
+ if (!test->newval) {
+ log_err("New value for sysctl is not set");
+ goto err;
+ }
+ if (write(fd, test->newval, strlen(test->newval)) == -1)
+ goto err;
+ } else {
+ log_err("Unexpected sysctl access: neither read nor write");
+ goto err;
+ }
+
+ goto out;
+err:
+ err = -1;
+out:
+ close(fd);
+ return err;
+}
+
+static int run_test_case(int cgfd, struct sysctl_test *test)
+{
+ enum bpf_attach_type atype = test->attach_type;
+ char sysctl_path[128];
+ int progfd = -1;
+ int err = 0;
+
+ printf("Test case: %s .. ", test->descr);
+
+ snprintf(sysctl_path, sizeof(sysctl_path), "/proc/sys/%s",
+ test->sysctl);
+
+ progfd = load_sysctl_prog(test, sysctl_path);
+ if (progfd < 0) {
+ if (test->result == LOAD_REJECT)
+ goto out;
+ else
+ goto err;
+ }
+
+ if (bpf_prog_attach(progfd, cgfd, atype, BPF_F_ALLOW_OVERRIDE) == -1) {
+ if (test->result == ATTACH_REJECT)
+ goto out;
+ else
+ goto err;
+ }
+
+ if (access_sysctl(sysctl_path, test) == -1) {
+ if (test->result == OP_EPERM && errno == EPERM)
+ goto out;
+ else
+ goto err;
+ }
+
+ if (test->result != SUCCESS) {
+ log_err("Unexpected failure");
+ goto err;
+ }
+
+ goto out;
+err:
+ err = -1;
+out:
+ /* Detaching w/o checking return code: best effort attempt. */
+ if (progfd != -1)
+ bpf_prog_detach(cgfd, atype);
+ 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 < 0)
+ 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;
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.