src/l2_packet/l2_packet.h

   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 */