diff options
Diffstat (limited to 'tools/testing/selftests/bpf/test_sysctl.c')
-rw-r--r-- | tools/testing/selftests/bpf/test_sysctl.c | 1567 |
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; +} |