1 /* 2 * WPA Supplicant - Layer2 packet interface definition 3 * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * Alternatively, this software may be distributed under the terms of BSD 10 * license. 11 * 12 * See README and COPYING for more details. 13 * 14 * This file defines an interface for layer 2 (link layer) packet sending and 15 * receiving. l2_packet_linux.c is one implementation for such a layer 2 16 * implementation using Linux packet sockets and l2_packet_pcap.c another one 17 * using libpcap and libdnet. When porting %wpa_supplicant to other operating 18 * systems, a new l2_packet implementation may need to be added. 19 */ 20 21 #ifndef L2_PACKET_H 22 #define L2_PACKET_H 23 24 /** 25 * struct l2_packet_data - Internal l2_packet data structure 26 * 27 * This structure is used by the l2_packet implementation to store its private 28 * data. Other files use a pointer to this data when calling the l2_packet 29 * functions, but the contents of this structure should not be used directly 30 * outside l2_packet implementation. 31 */ 32 struct l2_packet_data; 33 34 #ifdef _MSC_VER 35 #pragma pack(push, 1) 36 #endif /* _MSC_VER */ 37 38 struct l2_ethhdr { 39 u8 h_dest[ETH_ALEN]; 40 u8 h_source[ETH_ALEN]; 41 be16 h_proto; 42 } STRUCT_PACKED; 43 44 #ifdef _MSC_VER 45 #pragma pack(pop) 46 #endif /* _MSC_VER */ 47 48 /** 49 * l2_packet_init - Initialize l2_packet interface 50 * @ifname: Interface name 51 * @own_addr: Optional own MAC address if available from driver interface or 52 * %NULL if not available 53 * @protocol: Ethernet protocol number in host byte order 54 * @rx_callback: Callback function that will be called for each received packet 55 * @rx_callback_ctx: Callback data (ctx) for calls to rx_callback() 56 * @l2_hdr: 1 = include layer 2 header, 0 = do not include header 57 * Returns: Pointer to internal data or %NULL on failure 58 * 59 * rx_callback function will be called with src_addr pointing to the source 60 * address (MAC address) of the the packet. If l2_hdr is set to 0, buf 61 * points to len bytes of the payload after the layer 2 header and similarly, 62 * TX buffers start with payload. This behavior can be changed by setting 63 * l2_hdr=1 to include the layer 2 header in the data buffer. 64 */ 65 struct l2_packet_data * l2_packet_init( 66 const char *ifname, const u8 *own_addr, unsigned short protocol, 67 void (*rx_callback)(void *ctx, const u8 *src_addr, 68 const u8 *buf, size_t len), 69 void *rx_callback_ctx, int l2_hdr); 70 71 /** 72 * l2_packet_deinit - Deinitialize l2_packet interface 73 * @l2: Pointer to internal l2_packet data from l2_packet_init() 74 */ 75 void l2_packet_deinit(struct l2_packet_data *l2); 76 77 /** 78 * l2_packet_get_own_addr - Get own layer 2 address 79 * @l2: Pointer to internal l2_packet data from l2_packet_init() 80 * @addr: Buffer for the own address (6 bytes) 81 * Returns: 0 on success, -1 on failure 82 */ 83 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr); 84 85 /** 86 * l2_packet_send - Send a packet 87 * @l2: Pointer to internal l2_packet data from l2_packet_init() 88 * @dst_addr: Destination address for the packet (only used if l2_hdr == 0) 89 * @proto: Protocol/ethertype for the packet in host byte order (only used if 90 * l2_hdr == 0) 91 * @buf: Packet contents to be sent; including layer 2 header if l2_hdr was 92 * set to 1 in l2_packet_init() call. Otherwise, only the payload of the packet 93 * is included. 94 * @len: Length of the buffer (including l2 header only if l2_hdr == 1) 95 * Returns: >=0 on success, <0 on failure 96 */ 97 int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto, 98 const u8 *buf, size_t len); 99 100 /** 101 * l2_packet_get_ip_addr - Get the current IP address from the interface 102 * @l2: Pointer to internal l2_packet data from l2_packet_init() 103 * @buf: Buffer for the IP address in text format 104 * @len: Maximum buffer length 105 * Returns: 0 on success, -1 on failure 106 * 107 * This function can be used to get the current IP address from the interface 108 * bound to the l2_packet. This is mainly for status information and the IP 109 * address will be stored as an ASCII string. This function is not essential 110 * for %wpa_supplicant operation, so full implementation is not required. 111 * l2_packet implementation will need to define the function, but it can return 112 * -1 if the IP address information is not available. 113 */ 114 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len); 115 116 117 /** 118 * l2_packet_notify_auth_start - Notify l2_packet about start of authentication 119 * @l2: Pointer to internal l2_packet data from l2_packet_init() 120 * 121 * This function is called when authentication is expected to start, e.g., when 122 * association has been completed, in order to prepare l2_packet implementation 123 * for EAPOL frames. This function is used mainly if the l2_packet code needs 124 * to do polling in which case it can increasing polling frequency. This can 125 * also be an empty function if the l2_packet implementation does not benefit 126 * from knowing about the starting authentication. 127 */ 128 void l2_packet_notify_auth_start(struct l2_packet_data *l2); 129 130 #endif /* L2_PACKET_H */ 131