1 /* 2 * WPA Supplicant - Layer2 packet interface definition 3 * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi> 4 * 5 * This software may be distributed under the terms of the BSD license. 6 * See README for more details. 7 * 8 * This file defines an interface for layer 2 (link layer) packet sending and 9 * receiving. l2_packet_linux.c is one implementation for such a layer 2 10 * implementation using Linux packet sockets and l2_packet_pcap.c another one 11 * using libpcap and libdnet. When porting %wpa_supplicant to other operating 12 * systems, a new l2_packet implementation may need to be added. 13 */ 14 15 #ifndef L2_PACKET_H 16 #define L2_PACKET_H 17 18 #ifdef CONFIG_WAPI 19 #ifndef ETH_P_WAI 20 #define ETH_P_WAI 0x88b4 21 #endif 22 #endif /* WAPI */ 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 enum l2_packet_filter_type { 49 L2_PACKET_FILTER_DHCP, 50 L2_PACKET_FILTER_NDISC, 51 L2_PACKET_FILTER_PKTTYPE, 52 }; 53 54 /** 55 * l2_packet_init - Initialize l2_packet interface 56 * @ifname: Interface name 57 * @own_addr: Optional own MAC address if available from driver interface or 58 * %NULL if not available 59 * @protocol: Ethernet protocol number in host byte order 60 * @rx_callback: Callback function that will be called for each received packet 61 * @rx_callback_ctx: Callback data (ctx) for calls to rx_callback() 62 * @l2_hdr: 1 = include layer 2 header, 0 = do not include header 63 * Returns: Pointer to internal data or %NULL on failure 64 * 65 * rx_callback function will be called with src_addr pointing to the source 66 * address (MAC address) of the the packet. If l2_hdr is set to 0, buf 67 * points to len bytes of the payload after the layer 2 header and similarly, 68 * TX buffers start with payload. This behavior can be changed by setting 69 * l2_hdr=1 to include the layer 2 header in the data buffer. 70 * 71 * IF rx_callback is NULL, receive operation is not opened at all, i.e., only 72 * the TX path and additional helper functions for fetching MAC and IP 73 * addresses can be used. 74 */ 75 struct l2_packet_data * l2_packet_init( 76 const char *ifname, const u8 *own_addr, unsigned short protocol, 77 void (*rx_callback)(void *ctx, const u8 *src_addr, 78 const u8 *buf, size_t len), 79 void *rx_callback_ctx, int l2_hdr); 80 81 /** 82 * l2_packet_init_bridge - Like l2_packet_init() but with bridge workaround 83 * 84 * This version of l2_packet_init() can be used to enable a workaround for Linux 85 * packet socket in case of a station interface in a bridge. 86 */ 87 struct l2_packet_data * l2_packet_init_bridge( 88 const char *br_ifname, const char *ifname, const u8 *own_addr, 89 unsigned short protocol, 90 void (*rx_callback)(void *ctx, const u8 *src_addr, 91 const u8 *buf, size_t len), 92 void *rx_callback_ctx, int l2_hdr); 93 94 /** 95 * l2_packet_deinit - Deinitialize l2_packet interface 96 * @l2: Pointer to internal l2_packet data from l2_packet_init() 97 */ 98 void l2_packet_deinit(struct l2_packet_data *l2); 99 100 /** 101 * l2_packet_get_own_addr - Get own layer 2 address 102 * @l2: Pointer to internal l2_packet data from l2_packet_init() 103 * @addr: Buffer for the own address (6 bytes) 104 * Returns: 0 on success, -1 on failure 105 */ 106 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr); 107 108 /** 109 * l2_packet_send - Send a packet 110 * @l2: Pointer to internal l2_packet data from l2_packet_init() 111 * @dst_addr: Destination address for the packet (only used if l2_hdr == 0) 112 * @proto: Protocol/ethertype for the packet in host byte order (only used if 113 * l2_hdr == 0) 114 * @buf: Packet contents to be sent; including layer 2 header if l2_hdr was 115 * set to 1 in l2_packet_init() call. Otherwise, only the payload of the packet 116 * is included. 117 * @len: Length of the buffer (including l2 header only if l2_hdr == 1) 118 * Returns: >=0 on success, <0 on failure 119 */ 120 int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto, 121 const u8 *buf, size_t len); 122 123 /** 124 * l2_packet_get_ip_addr - Get the current IP address from the interface 125 * @l2: Pointer to internal l2_packet data from l2_packet_init() 126 * @buf: Buffer for the IP address in text format 127 * @len: Maximum buffer length 128 * Returns: 0 on success, -1 on failure 129 * 130 * This function can be used to get the current IP address from the interface 131 * bound to the l2_packet. This is mainly for status information and the IP 132 * address will be stored as an ASCII string. This function is not essential 133 * for %wpa_supplicant operation, so full implementation is not required. 134 * l2_packet implementation will need to define the function, but it can return 135 * -1 if the IP address information is not available. 136 */ 137 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len); 138 139 140 /** 141 * l2_packet_notify_auth_start - Notify l2_packet about start of authentication 142 * @l2: Pointer to internal l2_packet data from l2_packet_init() 143 * 144 * This function is called when authentication is expected to start, e.g., when 145 * association has been completed, in order to prepare l2_packet implementation 146 * for EAPOL frames. This function is used mainly if the l2_packet code needs 147 * to do polling in which case it can increasing polling frequency. This can 148 * also be an empty function if the l2_packet implementation does not benefit 149 * from knowing about the starting authentication. 150 */ 151 void l2_packet_notify_auth_start(struct l2_packet_data *l2); 152 153 /** 154 * l2_packet_set_packet_filter - Set socket filter for l2_packet 155 * @l2: Pointer to internal l2_packet data from l2_packet_init() 156 * @type: enum l2_packet_filter_type, type of filter 157 * Returns: 0 on success, -1 on failure 158 * 159 * This function is used to set the socket filter for l2_packet socket. 160 * 161 */ 162 int l2_packet_set_packet_filter(struct l2_packet_data *l2, 163 enum l2_packet_filter_type type); 164 165 #endif /* L2_PACKET_H */ 166