1 /*
2 * Copyright (C) 2019 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef NETDBPF_BPF_NET_HELPERS_H
18 #define NETDBPF_BPF_NET_HELPERS_H
19
20 #include <linux/bpf.h>
21 #include <linux/if_packet.h>
22 #include <stdbool.h>
23 #include <stdint.h>
24
25 // this returns 0 iff skb->sk is NULL
26 static uint64_t (*bpf_get_socket_cookie)(struct __sk_buff* skb) = (void*)BPF_FUNC_get_socket_cookie;
27
28 static uint32_t (*bpf_get_socket_uid)(struct __sk_buff* skb) = (void*)BPF_FUNC_get_socket_uid;
29 static int (*bpf_skb_load_bytes)(struct __sk_buff* skb, int off, void* to,
30 int len) = (void*)BPF_FUNC_skb_load_bytes;
31
32 static int64_t (*bpf_csum_diff)(__be32* from, __u32 from_size, __be32* to, __u32 to_size,
33 __wsum seed) = (void*)BPF_FUNC_csum_diff;
34
35 static int64_t (*bpf_csum_update)(struct __sk_buff* skb, __wsum csum) = (void*)BPF_FUNC_csum_update;
36
37 static int (*bpf_skb_change_proto)(struct __sk_buff* skb, __be16 proto,
38 __u64 flags) = (void*)BPF_FUNC_skb_change_proto;
39 static int (*bpf_l3_csum_replace)(struct __sk_buff* skb, __u32 offset, __u64 from, __u64 to,
40 __u64 flags) = (void*)BPF_FUNC_l3_csum_replace;
41 static int (*bpf_l4_csum_replace)(struct __sk_buff* skb, __u32 offset, __u64 from, __u64 to,
42 __u64 flags) = (void*)BPF_FUNC_l4_csum_replace;
43 static int (*bpf_redirect)(__u32 ifindex, __u64 flags) = (void*)BPF_FUNC_redirect;
44
45 static int (*bpf_skb_change_head)(struct __sk_buff* skb, __u32 head_room,
46 __u64 flags) = (void*)BPF_FUNC_skb_change_head;
47 static int (*bpf_skb_adjust_room)(struct __sk_buff* skb, __s32 len_diff, __u32 mode,
48 __u64 flags) = (void*)BPF_FUNC_skb_adjust_room;
49
50 // Android only supports little endian architectures
51 #define htons(x) (__builtin_constant_p(x) ? ___constant_swab16(x) : __builtin_bswap16(x))
52 #define htonl(x) (__builtin_constant_p(x) ? ___constant_swab32(x) : __builtin_bswap32(x))
53 #define ntohs(x) htons(x)
54 #define ntohl(x) htonl(x)
55
is_received_skb(struct __sk_buff * skb)56 static inline __always_inline __unused bool is_received_skb(struct __sk_buff* skb) {
57 return skb->pkt_type == PACKET_HOST || skb->pkt_type == PACKET_BROADCAST ||
58 skb->pkt_type == PACKET_MULTICAST;
59 }
60
61 #endif // NETDBPF_BPF_NET_HELPERS_H
62