1 /* 2 * WPA Supplicant - Layer2 packet interface definition 3 * Copyright (c) 2003-2005, Jouni Malinen <j (at) 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 #define MAC2STR(a) (a)[0], (a)[1], (a)[2], (a)[3], (a)[4], (a)[5] 25 #define MACSTR "%02x:%02x:%02x:%02x:%02x:%02x" 26 27 #ifndef ETH_P_EAPOL 28 #define ETH_P_EAPOL 0x888e 29 #endif 30 31 #ifndef ETH_P_RSN_PREAUTH 32 #define ETH_P_RSN_PREAUTH 0x88c7 33 #endif 34 35 /** 36 * struct l2_packet_data - Internal l2_packet data structure 37 * 38 * This structure is used by the l2_packet implementation to store its private 39 * data. Other files use a pointer to this data when calling the l2_packet 40 * functions, but the contents of this structure should not be used directly 41 * outside l2_packet implementation. 42 */ 43 struct l2_packet_data; 44 45 #ifdef _MSC_VER 46 #pragma pack(push, 1) 47 #endif /* _MSC_VER */ 48 49 struct l2_ethhdr { 50 u8 h_dest[ETH_ALEN]; 51 u8 h_source[ETH_ALEN]; 52 u16 h_proto; 53 } STRUCT_PACKED; 54 55 #ifdef _MSC_VER 56 #pragma pack(pop) 57 #endif /* _MSC_VER */ 58 59 /** 60 * l2_packet_init - Initialize l2_packet interface 61 * @ifname: Interface name 62 * @own_addr: Optional own MAC address if available from driver interface or 63 * %NULL if not available 64 * @protocol: Ethernet protocol number in host byte order 65 * @rx_callback: Callback function that will be called for each received packet 66 * @rx_callback_ctx: Callback data (ctx) for calls to rx_callback() 67 * @l2_hdr: 1 = include layer 2 header, 0 = do not include header 68 * Returns: Pointer to internal data or %NULL on failure 69 * 70 * rx_callback function will be called with src_addr pointing to the source 71 * address (MAC address) of the the packet. If l2_hdr is set to 0, buf 72 * points to len bytes of the payload after the layer 2 header and similarly, 73 * TX buffers start with payload. This behavior can be changed by setting 74 * l2_hdr=1 to include the layer 2 header in the data buffer. 75 */ 76 struct l2_packet_data * l2_packet_init( 77 const char *ifname, const u8 *own_addr, unsigned short protocol, 78 void (*rx_callback)(void *ctx, const u8 *src_addr, 79 const u8 *buf, size_t len), 80 void *rx_callback_ctx, int l2_hdr); 81 82 /** 83 * l2_packet_deinit - Deinitialize l2_packet interface 84 * @l2: Pointer to internal l2_packet data from l2_packet_init() 85 */ 86 void l2_packet_deinit(struct l2_packet_data *l2); 87 88 /** 89 * l2_packet_get_own_addr - Get own layer 2 address 90 * @l2: Pointer to internal l2_packet data from l2_packet_init() 91 * @addr: Buffer for the own address (6 bytes) 92 * Returns: 0 on success, -1 on failure 93 */ 94 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr); 95 96 /** 97 * l2_packet_send - Send a packet 98 * @l2: Pointer to internal l2_packet data from l2_packet_init() 99 * @dst_addr: Destination address for the packet (only used if l2_hdr == 0) 100 * @proto: Protocol/ethertype for the packet in host byte order (only used if 101 * l2_hdr == 0) 102 * @buf: Packet contents to be sent; including layer 2 header if l2_hdr was 103 * set to 1 in l2_packet_init() call. Otherwise, only the payload of the packet 104 * is included. 105 * @len: Length of the buffer (including l2 header only if l2_hdr == 1) 106 * Returns: >=0 on success, <0 on failure 107 */ 108 int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto, 109 const u8 *buf, size_t len); 110 111 /** 112 * l2_packet_get_ip_addr - Get the current IP address from the interface 113 * @l2: Pointer to internal l2_packet data from l2_packet_init() 114 * @buf: Buffer for the IP address in text format 115 * @len: Maximum buffer length 116 * Returns: 0 on success, -1 on failure 117 * 118 * This function can be used to get the current IP address from the interface 119 * bound to the l2_packet. This is mainly for status information and the IP 120 * address will be stored as an ASCII string. This function is not essential 121 * for %wpa_supplicant operation, so full implementation is not required. 122 * l2_packet implementation will need to define the function, but it can return 123 * -1 if the IP address information is not available. 124 */ 125 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len); 126 127 128 /** 129 * l2_packet_notify_auth_start - Notify l2_packet about start of authentication 130 * @l2: Pointer to internal l2_packet data from l2_packet_init() 131 * 132 * This function is called when authentication is expected to start, e.g., when 133 * association has been completed, in order to prepare l2_packet implementation 134 * for EAPOL frames. This function is used mainly if the l2_packet code needs 135 * to do polling in which case it can increasing polling frequency. This can 136 * also be an empty function if the l2_packet implementation does not benefit 137 * from knowing about the starting authentication. 138 */ 139 void l2_packet_notify_auth_start(struct l2_packet_data *l2); 140 141 #endif /* L2_PACKET_H */ 142
