/* * Copyright (c) 2017 Facebook * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. */ #define KBUILD_MODNAME "foo" #include <linux/ptrace.h> #include <linux/version.h> #include <uapi/linux/bpf.h> #include <uapi/linux/in6.h> #include "bpf_helpers.h" #define MAX_NR_PORTS 65536 /* map #0 */ struct bpf_map_def SEC("maps") port_a = { .type = BPF_MAP_TYPE_ARRAY, .key_size = sizeof(u32), .value_size = sizeof(int), .max_entries = MAX_NR_PORTS, }; /* map #1 */ struct bpf_map_def SEC("maps") port_h = { .type = BPF_MAP_TYPE_HASH, .key_size = sizeof(u32), .value_size = sizeof(int), .max_entries = 1, }; /* map #2 */ struct bpf_map_def SEC("maps") reg_result_h = { .type = BPF_MAP_TYPE_HASH, .key_size = sizeof(u32), .value_size = sizeof(int), .max_entries = 1, }; /* map #3 */ struct bpf_map_def SEC("maps") inline_result_h = { .type = BPF_MAP_TYPE_HASH, .key_size = sizeof(u32), .value_size = sizeof(int), .max_entries = 1, }; /* map #4 */ /* Test case #0 */ struct bpf_map_def SEC("maps") a_of_port_a = { .type = BPF_MAP_TYPE_ARRAY_OF_MAPS, .key_size = sizeof(u32), .inner_map_idx = 0, /* map_fd[0] is port_a */ .max_entries = MAX_NR_PORTS, }; /* map #5 */ /* Test case #1 */ struct bpf_map_def SEC("maps") h_of_port_a = { .type = BPF_MAP_TYPE_HASH_OF_MAPS, .key_size = sizeof(u32), .inner_map_idx = 0, /* map_fd[0] is port_a */ .max_entries = 1, }; /* map #6 */ /* Test case #2 */ struct bpf_map_def SEC("maps") h_of_port_h = { .type = BPF_MAP_TYPE_HASH_OF_MAPS, .key_size = sizeof(u32), .inner_map_idx = 1, /* map_fd[1] is port_h */ .max_entries = 1, }; static __always_inline int do_reg_lookup(void *inner_map, u32 port) { int *result; result = bpf_map_lookup_elem(inner_map, &port); return result ? *result : -ENOENT; } static __always_inline int do_inline_array_lookup(void *inner_map, u32 port) { int *result; if (inner_map != &port_a) return -EINVAL; result = bpf_map_lookup_elem(&port_a, &port); return result ? *result : -ENOENT; } static __always_inline int do_inline_hash_lookup(void *inner_map, u32 port) { int *result; if (inner_map != &port_h) return -EINVAL; result = bpf_map_lookup_elem(&port_h, &port); return result ? *result : -ENOENT; } SEC("kprobe/sys_connect") int trace_sys_connect(struct pt_regs *ctx) { struct sockaddr_in6 *in6; u16 test_case, port, dst6[8]; int addrlen, ret, inline_ret, ret_key = 0; u32 port_key; void *outer_map, *inner_map; bool inline_hash = false; in6 = (struct sockaddr_in6 *)PT_REGS_PARM2(ctx); addrlen = (int)PT_REGS_PARM3(ctx); if (addrlen != sizeof(*in6)) return 0; ret = bpf_probe_read(dst6, sizeof(dst6), &in6->sin6_addr); if (ret) { inline_ret = ret; goto done; } if (dst6[0] != 0xdead || dst6[1] != 0xbeef) return 0; test_case = dst6[7]; ret = bpf_probe_read(&port, sizeof(port), &in6->sin6_port); if (ret) { inline_ret = ret; goto done; } port_key = port; ret = -ENOENT; if (test_case == 0) { outer_map = &a_of_port_a; } else if (test_case == 1) { outer_map = &h_of_port_a; } else if (test_case == 2) { outer_map = &h_of_port_h; } else { ret = __LINE__; inline_ret = ret; goto done; } inner_map = bpf_map_lookup_elem(outer_map, &port_key); if (!inner_map) { ret = __LINE__; inline_ret = ret; goto done; } ret = do_reg_lookup(inner_map, port_key); if (test_case == 0 || test_case == 1) inline_ret = do_inline_array_lookup(inner_map, port_key); else inline_ret = do_inline_hash_lookup(inner_map, port_key); done: bpf_map_update_elem(®_result_h, &ret_key, &ret, BPF_ANY); bpf_map_update_elem(&inline_result_h, &ret_key, &inline_ret, BPF_ANY); return 0; } char _license[] SEC("license") = "GPL"; u32 _version SEC("version") = LINUX_VERSION_CODE;