1 /* 2 * WPA Supplicant - Layer2 packet interface definition 3 * Copyright (c) 2003-2005, Jouni Malinen <j (at) 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 /** 19 * struct l2_packet_data - Internal l2_packet data structure 20 * 21 * This structure is used by the l2_packet implementation to store its private 22 * data. Other files use a pointer to this data when calling the l2_packet 23 * functions, but the contents of this structure should not be used directly 24 * outside l2_packet implementation. 25 */ 26 struct l2_packet_data; 27 28 #ifdef _MSC_VER 29 #pragma pack(push, 1) 30 #endif /* _MSC_VER */ 31 32 struct l2_ethhdr { 33 u8 h_dest[ETH_ALEN]; 34 u8 h_source[ETH_ALEN]; 35 be16 h_proto; 36 } STRUCT_PACKED; 37 38 #ifdef _MSC_VER 39 #pragma pack(pop) 40 #endif /* _MSC_VER */ 41 42 enum l2_packet_filter_type { 43 L2_PACKET_FILTER_DHCP, 44 L2_PACKET_FILTER_NDISC, 45 }; 46 47 /** 48 * l2_packet_init - Initialize l2_packet interface 49 * @ifname: Interface name 50 * @own_addr: Optional own MAC address if available from driver interface or 51 * %NULL if not available 52 * @protocol: Ethernet protocol number in host byte order 53 * @rx_callback: Callback function that will be called for each received packet 54 * @rx_callback_ctx: Callback data (ctx) for calls to rx_callback() 55 * @l2_hdr: 1 = include layer 2 header, 0 = do not include header 56 * Returns: Pointer to internal data or %NULL on failure 57 * 58 * rx_callback function will be called with src_addr pointing to the source 59 * address (MAC address) of the the packet. If l2_hdr is set to 0, buf 60 * points to len bytes of the payload after the layer 2 header and similarly, 61 * TX buffers start with payload. This behavior can be changed by setting 62 * l2_hdr=1 to include the layer 2 header in the data buffer. 63 */ 64 struct l2_packet_data * l2_packet_init( 65 const char *ifname, const u8 *own_addr, unsigned short protocol, 66 void (*rx_callback)(void *ctx, const u8 *src_addr, 67 const u8 *buf, size_t len), 68 void *rx_callback_ctx, int l2_hdr); 69 70 /** 71 * l2_packet_init_bridge - Like l2_packet_init() but with bridge workaround 72 * 73 * This version of l2_packet_init() can be used to enable a workaround for Linux 74 * packet socket in case of a station interface in a bridge. 75 */ 76 struct l2_packet_data * l2_packet_init_bridge( 77 const char *br_ifname, const char *ifname, const u8 *own_addr, 78 unsigned short protocol, 79 void (*rx_callback)(void *ctx, const u8 *src_addr, 80 const u8 *buf, size_t len), 81 void *rx_callback_ctx, int l2_hdr); 82 83 /** 84 * l2_packet_deinit - Deinitialize l2_packet interface 85 * @l2: Pointer to internal l2_packet data from l2_packet_init() 86 */ 87 void l2_packet_deinit(struct l2_packet_data *l2); 88 89 /** 90 * l2_packet_get_own_addr - Get own layer 2 address 91 * @l2: Pointer to internal l2_packet data from l2_packet_init() 92 * @addr: Buffer for the own address (6 bytes) 93 * Returns: 0 on success, -1 on failure 94 */ 95 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr); 96 97 /** 98 * l2_packet_send - Send a packet 99 * @l2: Pointer to internal l2_packet data from l2_packet_init() 100 * @dst_addr: Destination address for the packet (only used if l2_hdr == 0) 101 * @proto: Protocol/ethertype for the packet in host byte order (only used if 102 * l2_hdr == 0) 103 * @buf: Packet contents to be sent; including layer 2 header if l2_hdr was 104 * set to 1 in l2_packet_init() call. Otherwise, only the payload of the packet 105 * is included. 106 * @len: Length of the buffer (including l2 header only if l2_hdr == 1) 107 * Returns: >=0 on success, <0 on failure 108 */ 109 int l2_packet_send(struct l2_packet_data *l2, const u8 *dst_addr, u16 proto, 110 const u8 *buf, size_t len); 111 112 /** 113 * l2_packet_get_ip_addr - Get the current IP address from the interface 114 * @l2: Pointer to internal l2_packet data from l2_packet_init() 115 * @buf: Buffer for the IP address in text format 116 * @len: Maximum buffer length 117 * Returns: 0 on success, -1 on failure 118 * 119 * This function can be used to get the current IP address from the interface 120 * bound to the l2_packet. This is mainly for status information and the IP 121 * address will be stored as an ASCII string. This function is not essential 122 * for %wpa_supplicant operation, so full implementation is not required. 123 * l2_packet implementation will need to define the function, but it can return 124 * -1 if the IP address information is not available. 125 */ 126 int l2_packet_get_ip_addr(struct l2_packet_data *l2, char *buf, size_t len); 127 128 129 /** 130 * l2_packet_notify_auth_start - Notify l2_packet about start of authentication 131 * @l2: Pointer to internal l2_packet data from l2_packet_init() 132 * 133 * This function is called when authentication is expected to start, e.g., when 134 * association has been completed, in order to prepare l2_packet implementation 135 * for EAPOL frames. This function is used mainly if the l2_packet code needs 136 * to do polling in which case it can increasing polling frequency. This can 137 * also be an empty function if the l2_packet implementation does not benefit 138 * from knowing about the starting authentication. 139 */ 140 void l2_packet_notify_auth_start(struct l2_packet_data *l2); 141 142 /** 143 * l2_packet_set_packet_filter - Set socket filter for l2_packet 144 * @l2: Pointer to internal l2_packet data from l2_packet_init() 145 * @type: enum l2_packet_filter_type, type of filter 146 * Returns: 0 on success, -1 on failure 147 * 148 * This function is used to set the socket filter for l2_packet socket. 149 * 150 */ 151 int l2_packet_set_packet_filter(struct l2_packet_data *l2, 152 enum l2_packet_filter_type type); 153 154 #endif /* L2_PACKET_H */ 155
