557 lines
13 KiB
C
557 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (c) 2018 Facebook
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#include <stdio.h>
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#include <unistd.h>
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#include <arpa/inet.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <linux/filter.h>
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#include <bpf/bpf.h>
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#include "cgroup_helpers.h"
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#include <bpf/bpf_endian.h>
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#include "bpf_util.h"
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#define CG_PATH "/foo"
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#define MAX_INSNS 512
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char bpf_log_buf[BPF_LOG_BUF_SIZE];
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static bool verbose = false;
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struct sock_test {
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const char *descr;
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/* BPF prog properties */
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struct bpf_insn insns[MAX_INSNS];
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enum bpf_attach_type expected_attach_type;
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enum bpf_attach_type attach_type;
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/* Socket properties */
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int domain;
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int type;
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/* Endpoint to bind() to */
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const char *ip;
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unsigned short port;
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unsigned short port_retry;
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/* Expected test result */
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enum {
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LOAD_REJECT,
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ATTACH_REJECT,
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BIND_REJECT,
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SUCCESS,
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RETRY_SUCCESS,
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RETRY_REJECT
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} result;
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};
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static struct sock_test tests[] = {
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{
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.descr = "bind4 load with invalid access: src_ip6",
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.insns = {
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BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, src_ip6[0])),
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
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.attach_type = BPF_CGROUP_INET4_POST_BIND,
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.result = LOAD_REJECT,
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},
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{
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.descr = "bind4 load with invalid access: mark",
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.insns = {
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BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, mark)),
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
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.attach_type = BPF_CGROUP_INET4_POST_BIND,
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.result = LOAD_REJECT,
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},
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{
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.descr = "bind6 load with invalid access: src_ip4",
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.insns = {
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BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, src_ip4)),
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
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.attach_type = BPF_CGROUP_INET6_POST_BIND,
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.result = LOAD_REJECT,
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},
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{
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.descr = "sock_create load with invalid access: src_port",
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.insns = {
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BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, src_port)),
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
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.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
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.result = LOAD_REJECT,
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},
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{
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.descr = "sock_create load w/o expected_attach_type (compat mode)",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = 0,
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.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
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.domain = AF_INET,
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.type = SOCK_STREAM,
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.ip = "127.0.0.1",
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.port = 8097,
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.result = SUCCESS,
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},
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{
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.descr = "sock_create load w/ expected_attach_type",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
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.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
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.domain = AF_INET,
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.type = SOCK_STREAM,
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.ip = "127.0.0.1",
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.port = 8097,
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.result = SUCCESS,
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},
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{
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.descr = "attach type mismatch bind4 vs bind6",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
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.attach_type = BPF_CGROUP_INET6_POST_BIND,
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.result = ATTACH_REJECT,
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},
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{
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.descr = "attach type mismatch bind6 vs bind4",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
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.attach_type = BPF_CGROUP_INET4_POST_BIND,
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.result = ATTACH_REJECT,
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},
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{
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.descr = "attach type mismatch default vs bind4",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = 0,
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.attach_type = BPF_CGROUP_INET4_POST_BIND,
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.result = ATTACH_REJECT,
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},
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{
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.descr = "attach type mismatch bind6 vs sock_create",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
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.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
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.result = ATTACH_REJECT,
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},
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{
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.descr = "bind4 reject all",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
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.attach_type = BPF_CGROUP_INET4_POST_BIND,
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.domain = AF_INET,
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.type = SOCK_STREAM,
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.ip = "0.0.0.0",
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.result = BIND_REJECT,
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},
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{
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.descr = "bind6 reject all",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
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.attach_type = BPF_CGROUP_INET6_POST_BIND,
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.domain = AF_INET6,
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.type = SOCK_STREAM,
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.ip = "::",
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.result = BIND_REJECT,
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},
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{
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.descr = "bind6 deny specific IP & port",
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.insns = {
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BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
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/* if (ip == expected && port == expected) */
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, src_ip6[3])),
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BPF_JMP_IMM(BPF_JNE, BPF_REG_7,
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__bpf_constant_ntohl(0x00000001), 4),
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, src_port)),
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BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x2001, 2),
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/* return DENY; */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_JMP_A(1),
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/* else return ALLOW; */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
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.attach_type = BPF_CGROUP_INET6_POST_BIND,
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.domain = AF_INET6,
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.type = SOCK_STREAM,
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.ip = "::1",
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.port = 8193,
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.result = BIND_REJECT,
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},
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{
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.descr = "bind4 allow specific IP & port",
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.insns = {
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BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
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/* if (ip == expected && port == expected) */
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, src_ip4)),
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BPF_JMP_IMM(BPF_JNE, BPF_REG_7,
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__bpf_constant_ntohl(0x7F000001), 4),
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, src_port)),
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BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2),
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/* return ALLOW; */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_JMP_A(1),
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/* else return DENY; */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
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.attach_type = BPF_CGROUP_INET4_POST_BIND,
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.domain = AF_INET,
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.type = SOCK_STREAM,
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.ip = "127.0.0.1",
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.port = 4098,
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.result = SUCCESS,
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},
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{
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.descr = "bind4 deny specific IP & port of TCP, and retry",
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.insns = {
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BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
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/* if (ip == expected && port == expected) */
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, src_ip4)),
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BPF_JMP_IMM(BPF_JNE, BPF_REG_7,
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__bpf_constant_ntohl(0x7F000001), 4),
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, src_port)),
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BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2),
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/* return DENY; */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_JMP_A(1),
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/* else return ALLOW; */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
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.attach_type = BPF_CGROUP_INET4_POST_BIND,
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.domain = AF_INET,
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.type = SOCK_STREAM,
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.ip = "127.0.0.1",
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.port = 4098,
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.port_retry = 5000,
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.result = RETRY_SUCCESS,
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},
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{
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.descr = "bind4 deny specific IP & port of UDP, and retry",
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.insns = {
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BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
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/* if (ip == expected && port == expected) */
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, src_ip4)),
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BPF_JMP_IMM(BPF_JNE, BPF_REG_7,
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__bpf_constant_ntohl(0x7F000001), 4),
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, src_port)),
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BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2),
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/* return DENY; */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_JMP_A(1),
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/* else return ALLOW; */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
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.attach_type = BPF_CGROUP_INET4_POST_BIND,
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.domain = AF_INET,
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.type = SOCK_DGRAM,
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.ip = "127.0.0.1",
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.port = 4098,
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.port_retry = 5000,
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.result = RETRY_SUCCESS,
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},
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{
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.descr = "bind6 deny specific IP & port, and retry",
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.insns = {
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BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
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/* if (ip == expected && port == expected) */
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, src_ip6[3])),
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BPF_JMP_IMM(BPF_JNE, BPF_REG_7,
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__bpf_constant_ntohl(0x00000001), 4),
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BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
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offsetof(struct bpf_sock, src_port)),
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BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x2001, 2),
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/* return DENY; */
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_JMP_A(1),
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/* else return ALLOW; */
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
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.attach_type = BPF_CGROUP_INET6_POST_BIND,
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.domain = AF_INET6,
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.type = SOCK_STREAM,
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.ip = "::1",
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.port = 8193,
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.port_retry = 9000,
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.result = RETRY_SUCCESS,
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},
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{
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.descr = "bind4 allow all",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET4_POST_BIND,
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.attach_type = BPF_CGROUP_INET4_POST_BIND,
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.domain = AF_INET,
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.type = SOCK_STREAM,
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.ip = "0.0.0.0",
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.result = SUCCESS,
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},
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{
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.descr = "bind6 allow all",
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.insns = {
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BPF_MOV64_IMM(BPF_REG_0, 1),
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BPF_EXIT_INSN(),
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},
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.expected_attach_type = BPF_CGROUP_INET6_POST_BIND,
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.attach_type = BPF_CGROUP_INET6_POST_BIND,
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.domain = AF_INET6,
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.type = SOCK_STREAM,
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.ip = "::",
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.result = SUCCESS,
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},
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};
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static size_t probe_prog_length(const struct bpf_insn *fp)
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{
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size_t len;
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for (len = MAX_INSNS - 1; len > 0; --len)
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if (fp[len].code != 0 || fp[len].imm != 0)
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break;
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return len + 1;
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}
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static int load_sock_prog(const struct bpf_insn *prog,
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enum bpf_attach_type attach_type)
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{
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LIBBPF_OPTS(bpf_prog_load_opts, opts);
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int ret, insn_cnt;
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insn_cnt = probe_prog_length(prog);
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opts.expected_attach_type = attach_type;
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opts.log_buf = bpf_log_buf;
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opts.log_size = BPF_LOG_BUF_SIZE;
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opts.log_level = 2;
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ret = bpf_prog_load(BPF_PROG_TYPE_CGROUP_SOCK, NULL, "GPL", prog, insn_cnt, &opts);
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if (verbose && ret < 0)
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fprintf(stderr, "%s\n", bpf_log_buf);
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return ret;
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}
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static int attach_sock_prog(int cgfd, int progfd,
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enum bpf_attach_type attach_type)
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{
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return bpf_prog_attach(progfd, cgfd, attach_type, BPF_F_ALLOW_OVERRIDE);
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}
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static int bind_sock(int domain, int type, const char *ip,
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unsigned short port, unsigned short port_retry)
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{
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struct sockaddr_storage addr;
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struct sockaddr_in6 *addr6;
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struct sockaddr_in *addr4;
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int sockfd = -1;
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socklen_t len;
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int res = SUCCESS;
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sockfd = socket(domain, type, 0);
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if (sockfd < 0)
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goto err;
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memset(&addr, 0, sizeof(addr));
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if (domain == AF_INET) {
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len = sizeof(struct sockaddr_in);
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addr4 = (struct sockaddr_in *)&addr;
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addr4->sin_family = domain;
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addr4->sin_port = htons(port);
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if (inet_pton(domain, ip, (void *)&addr4->sin_addr) != 1)
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goto err;
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} else if (domain == AF_INET6) {
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len = sizeof(struct sockaddr_in6);
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addr6 = (struct sockaddr_in6 *)&addr;
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addr6->sin6_family = domain;
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addr6->sin6_port = htons(port);
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if (inet_pton(domain, ip, (void *)&addr6->sin6_addr) != 1)
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goto err;
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} else {
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goto err;
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}
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if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1) {
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/* sys_bind() may fail for different reasons, errno has to be
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* checked to confirm that BPF program rejected it.
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*/
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if (errno != EPERM)
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goto err;
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if (port_retry)
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goto retry;
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res = BIND_REJECT;
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goto out;
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}
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goto out;
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retry:
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if (domain == AF_INET)
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addr4->sin_port = htons(port_retry);
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else
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addr6->sin6_port = htons(port_retry);
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if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1) {
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if (errno != EPERM)
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goto err;
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res = RETRY_REJECT;
|
|
} else {
|
|
res = RETRY_SUCCESS;
|
|
}
|
|
goto out;
|
|
err:
|
|
res = -1;
|
|
out:
|
|
close(sockfd);
|
|
return res;
|
|
}
|
|
|
|
static int run_test_case(int cgfd, const struct sock_test *test)
|
|
{
|
|
int progfd = -1;
|
|
int err = 0;
|
|
int res;
|
|
|
|
printf("Test case: %s .. ", test->descr);
|
|
progfd = load_sock_prog(test->insns, test->expected_attach_type);
|
|
if (progfd < 0) {
|
|
if (test->result == LOAD_REJECT)
|
|
goto out;
|
|
else
|
|
goto err;
|
|
}
|
|
|
|
if (attach_sock_prog(cgfd, progfd, test->attach_type) < 0) {
|
|
if (test->result == ATTACH_REJECT)
|
|
goto out;
|
|
else
|
|
goto err;
|
|
}
|
|
|
|
res = bind_sock(test->domain, test->type, test->ip, test->port,
|
|
test->port_retry);
|
|
if (res > 0 && test->result == res)
|
|
goto out;
|
|
|
|
err:
|
|
err = -1;
|
|
out:
|
|
/* Detaching w/o checking return code: best effort attempt. */
|
|
if (progfd != -1)
|
|
bpf_prog_detach(cgfd, test->attach_type);
|
|
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;
|
|
|
|
cgfd = cgroup_setup_and_join(CG_PATH);
|
|
if (cgfd < 0)
|
|
goto err;
|
|
|
|
/* Use libbpf 1.0 API mode */
|
|
libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
|
|
|
|
if (run_tests(cgfd))
|
|
goto err;
|
|
|
|
goto out;
|
|
err:
|
|
err = -1;
|
|
out:
|
|
close(cgfd);
|
|
cleanup_cgroup_environment();
|
|
return err;
|
|
}
|