include/net/caif/cfpkt.h

   1 /*
   2  * Copyright (C) ST-Ericsson AB 2010
   3  * Author:      Sjur Brendeland/sjur.brandeland@stericsson.com
   4  * License terms: GNU General Public License (GPL) version 2
   5  */
   6
   7 #ifndef CFPKT_H_
   8 #define CFPKT_H_
   9 #include <net/caif/caif_layer.h>
  10 #include <linux/types.h>
  11 struct cfpkt;
  12
  13 /* Create a CAIF packet.
  14  * len: Length of packet to be created
  15  * @return New packet.
  16  */
  17 struct cfpkt *cfpkt_create(u16 len);
  18
  19 /*
  20  * Destroy a CAIF Packet.
  21  * pkt Packet to be destoyed.
  22  */
  23 void cfpkt_destroy(struct cfpkt *pkt);
  24
  25 /*
  26  * Extract header from packet.
  27  *
  28  * pkt Packet to extract header data from.
  29  * data Pointer to copy the header data into.
  30  * len Length of head data to copy.
  31  * @return zero on success and error code upon failure
  32  */
  33 int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len);
  34
  35 /*
  36  * Peek header from packet.
  37  * Reads data from packet without changing packet.
  38  *
  39  * pkt Packet to extract header data from.
  40  * data Pointer to copy the header data into.
  41  * len Length of head data to copy.
  42  * @return zero on success and error code upon failure
  43  */
  44 int cfpkt_peek_head(struct cfpkt *pkt, void *data, u16 len);
  45
  46 /*
  47  * Extract header from trailer (end of packet).
  48  *
  49  * pkt Packet to extract header data from.
  50  * data Pointer to copy the trailer data into.
  51  * len Length of header data to copy.
  52  * @return zero on success and error code upon failure
  53  */
  54 int cfpkt_extr_trail(struct cfpkt *pkt, void *data, u16 len);
  55
  56 /*
  57  * Add header to packet.
  58  *
  59  *
  60  * pkt Packet to add header data to.
  61  * data Pointer to data to copy into the header.
  62  * len Length of header data to copy.
  63  * @return zero on success and error code upon failure
  64  */
  65 int cfpkt_add_head(struct cfpkt *pkt, const void *data, u16 len);
  66
  67 /*
  68  * Add trailer to packet.
  69  *
  70  *
  71  * pkt Packet to add trailer data to.
  72  * data Pointer to data to copy into the trailer.
  73  * len Length of trailer data to copy.
  74  * @return zero on success and error code upon failure
  75  */
  76 int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len);
  77
  78 /*
  79  * Pad trailer on packet.
  80  * Moves data pointer in packet, no content copied.
  81  *
  82  * pkt Packet in which to pad trailer.
  83  * len Length of padding to add.
  84  * @return zero on success and error code upon failure
  85  */
  86 int cfpkt_pad_trail(struct cfpkt *pkt, u16 len);
  87
  88 /*
  89  * Add a single byte to packet body (tail).
  90  *
  91  * pkt Packet in which to add byte.
  92  * data Byte to add.
  93  * @return zero on success and error code upon failure
  94  */
  95 int cfpkt_addbdy(struct cfpkt *pkt, const u8 data);
  96
  97 /*
  98  * Add a data to packet body (tail).
  99  *
 100  * pkt Packet in which to add data.
 101  * data Pointer to data to copy into the packet body.
 102  * len Length of data to add.
 103  * @return zero on success and error code upon failure
 104  */
 105 int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len);
 106
 107 /*
 108  * Checks whether there are more data to process in packet.
 109  * pkt Packet to check.
 110  * @return true if more data are available in packet false otherwise
 111  */
 112 bool cfpkt_more(struct cfpkt *pkt);
 113
 114 /*
 115  * Checks whether the packet is erroneous,
 116  * i.e. if it has been attempted to extract more data than available in packet
 117  * or writing more data than has been allocated in cfpkt_create().
 118  * pkt Packet to check.
 119  * @return true on error false otherwise
 120  */
 121 bool cfpkt_erroneous(struct cfpkt *pkt);
 122
 123 /*
 124  * Get the packet length.
 125  * pkt Packet to get length from.
 126  * @return Number of bytes in packet.
 127  */
 128 u16 cfpkt_getlen(struct cfpkt *pkt);
 129
 130 /*
 131  * Set the packet length, by adjusting the trailer pointer according to length.
 132  * pkt Packet to set length.
 133  * len Packet length.
 134  * @return Number of bytes in packet.
 135  */
 136 int cfpkt_setlen(struct cfpkt *pkt, u16 len);
 137
 138 /*
 139  * cfpkt_append - Appends a packet's data to another packet.
 140  * dstpkt:    Packet to append data into, WILL BE FREED BY THIS FUNCTION
 141  * addpkt:    Packet to be appended and automatically released,
 142  *            WILL BE FREED BY THIS FUNCTION.
 143  * expectlen: Packet's expected total length. This should be considered
 144  *            as a hint.
 145  * NB: Input packets will be destroyed after appending and cannot be used
 146  * after calling this function.
 147  * @return    The new appended packet.
 148  */
 149 struct cfpkt *cfpkt_append(struct cfpkt *dstpkt, struct cfpkt *addpkt,
 150                       u16 expectlen);
 151
 152 /*
 153  * cfpkt_split - Split a packet into two packets at the specified split point.
 154  * pkt: Packet to be split (will contain the first part of the data on exit)
 155  * pos: Position to split packet in two parts.
 156  * @return The new packet, containing the second part of the data.
 157  */
 158 struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos);
 159
 160 /*
 161  * Iteration function, iterates the packet buffers from start to end.
 162  *
 163  * Checksum iteration function used to iterate buffers
 164  * (we may have packets consisting of a chain of buffers)
 165  * pkt:       Packet to calculate checksum for
 166  * iter_func: Function pointer to iteration function
 167  * chks:      Checksum calculated so far.
 168  * buf:       Pointer to the buffer to checksum
 169  * len:       Length of buf.
 170  * data:      Initial checksum value.
 171  * @return    Checksum of buffer.
 172  */
 173
 174 u16 cfpkt_iterate(struct cfpkt *pkt,
 175                 u16 (*iter_func)(u16 chks, void *buf, u16 len),
 176                 u16 data);
 177
 178 /* Map from a "native" packet (e.g. Linux Socket Buffer) to a CAIF packet.
 179  *  dir - Direction indicating whether this packet is to be sent or received.
 180  *  nativepkt  - The native packet to be transformed to a CAIF packet
 181  *  @return The mapped CAIF Packet CFPKT.
 182  */
 183 struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt);
 184
 185 /* Map from a CAIF packet to a "native" packet (e.g. Linux Socket Buffer).
 186  *  pkt  - The CAIF packet to be transformed into a "native" packet.
 187  *  @return The native packet transformed from a CAIF packet.
 188  */
 189 void *cfpkt_tonative(struct cfpkt *pkt);
 190
 191
 192 /*
 193  * Returns packet information for a packet.
 194  * pkt Packet to get info from;
 195  * @return Packet information
 196  */
 197 struct caif_payload_info *cfpkt_info(struct cfpkt *pkt);
 198 #endif                          /* CFPKT_H_ */