1 /*
2  * Copyright 2015, 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 APF_INTERPRETER_H_
18 #define APF_INTERPRETER_H_
19 
20 #include <stdint.h>
21 
22 #ifdef __cplusplus
23 extern "C" {
24 #endif
25 
26 /**
27  * Version of APF instruction set processed by accept_packet().
28  * Should be returned by wifi_get_packet_filter_info.
29  */
30 #define APF_VERSION 4
31 
32 /**
33  * Runs a packet filtering program over a packet.
34  *
35  * The text section containing the program instructions starts at address
36  * program and stops at + program_len - 1, and the writable data section
37  * begins at program + program_len and ends at program + ram_len - 1,
38  * as described in the following diagram:
39  *
40  *     program         program + program_len    program + ram_len
41  *        |    text section    |      data section      |
42  *        +--------------------+------------------------+
43  *
44  * @param program the program bytecode, followed by the writable data region.
45  * @param program_len the length in bytes of the read-only portion of the APF
46  *                    buffer pointed to by {@code program}.
47  * @param ram_len total length of the APF buffer pointed to by {@code program},
48  *                including the read-only bytecode portion and the read-write
49  *                data portion.
50  * @param packet the packet bytes, starting from the 802.3 header and not
51  *               including any CRC bytes at the end.
52  * @param packet_len the length of {@code packet} in bytes.
53  * @param filter_age the number of seconds since the filter was programmed.
54  *
55  * @return non-zero if packet should be passed to AP, zero if
56  *         packet should be dropped.
57  */
58 int accept_packet(uint8_t* program, uint32_t program_len, uint32_t ram_len,
59                   const uint8_t* packet, uint32_t packet_len,
60                   uint32_t filter_age);
61 
62 #ifdef __cplusplus
63 }
64 #endif
65 
66 #endif  // APF_INTERPRETER_H_
67