include/net/caif/cfpkt.h

   1 /*
   2  * Copyright (C) ST-Ericsson AB 2010
   3  * Author:      Sjur Brendeland
   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 static inline u8 cfpkt_extr_head_u8(struct cfpkt *pkt)
  36 {
  37         u8 tmp;
  38
  39         cfpkt_extr_head(pkt, &tmp, 1);
  40
  41         return tmp;
  42 }
  43
  44 static inline u16 cfpkt_extr_head_u16(struct cfpkt *pkt)
  45 {
  46         __le16 tmp;
  47
  48         cfpkt_extr_head(pkt, &tmp, 2);
  49
  50         return le16_to_cpu(tmp);
  51 }
  52
  53 static inline u32 cfpkt_extr_head_u32(struct cfpkt *pkt)
  54 {
  55         __le32 tmp;
  56
  57         cfpkt_extr_head(pkt, &tmp, 4);
  58
  59         return le32_to_cpu(tmp);
  60 }
  61
  62 /*
  63  * Peek header from packet.
  64  * Reads data from packet without changing packet.
  65  *
  66  * pkt Packet to extract header data from.
  67  * data Pointer to copy the header data into.
  68  * len Length of head data to copy.
  69  * @return zero on success and error code upon failure
  70  */
  71 int cfpkt_peek_head(struct cfpkt *pkt, void *data, u16 len);
  72
  73 /*
  74  * Extract header from trailer (end of packet).
  75  *
  76  * pkt Packet to extract header data from.
  77  * data Pointer to copy the trailer data into.
  78  * len Length of header data to copy.
  79  * @return zero on success and error code upon failure
  80  */
  81 int cfpkt_extr_trail(struct cfpkt *pkt, void *data, u16 len);
  82
  83 /*
  84  * Add header to packet.
  85  *
  86  *
  87  * pkt Packet to add header data to.
  88  * data Pointer to data to copy into the header.
  89  * len Length of header data to copy.
  90  * @return zero on success and error code upon failure
  91  */
  92 int cfpkt_add_head(struct cfpkt *pkt, const void *data, u16 len);
  93
  94 /*
  95  * Add trailer to packet.
  96  *
  97  *
  98  * pkt Packet to add trailer data to.
  99  * data Pointer to data to copy into the trailer.
 100  * len Length of trailer data to copy.
 101  * @return zero on success and error code upon failure
 102  */
 103 int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len);
 104
 105 /*
 106  * Pad trailer on packet.
 107  * Moves data pointer in packet, no content copied.
 108  *
 109  * pkt Packet in which to pad trailer.
 110  * len Length of padding to add.
 111  * @return zero on success and error code upon failure
 112  */
 113 int cfpkt_pad_trail(struct cfpkt *pkt, u16 len);
 114
 115 /*
 116  * Add a single byte to packet body (tail).
 117  *
 118  * pkt Packet in which to add byte.
 119  * data Byte to add.
 120  * @return zero on success and error code upon failure
 121  */
 122 int cfpkt_addbdy(struct cfpkt *pkt, const u8 data);
 123
 124 /*
 125  * Add a data to packet body (tail).
 126  *
 127  * pkt Packet in which to add data.
 128  * data Pointer to data to copy into the packet body.
 129  * len Length of data to add.
 130  * @return zero on success and error code upon failure
 131  */
 132 int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len);
 133
 134 /*
 135  * Checks whether there are more data to process in packet.
 136  * pkt Packet to check.
 137  * @return true if more data are available in packet false otherwise
 138  */
 139 bool cfpkt_more(struct cfpkt *pkt);
 140
 141 /*
 142  * Checks whether the packet is erroneous,
 143  * i.e. if it has been attempted to extract more data than available in packet
 144  * or writing more data than has been allocated in cfpkt_create().
 145  * pkt Packet to check.
 146  * @return true on error false otherwise
 147  */
 148 bool cfpkt_erroneous(struct cfpkt *pkt);
 149
 150 /*
 151  * Get the packet length.
 152  * pkt Packet to get length from.
 153  * @return Number of bytes in packet.
 154  */
 155 u16 cfpkt_getlen(struct cfpkt *pkt);
 156
 157 /*
 158  * Set the packet length, by adjusting the trailer pointer according to length.
 159  * pkt Packet to set length.
 160  * len Packet length.
 161  * @return Number of bytes in packet.
 162  */
 163 int cfpkt_setlen(struct cfpkt *pkt, u16 len);
 164
 165 /*
 166  * cfpkt_append - Appends a packet's data to another packet.
 167  * dstpkt:    Packet to append data into, WILL BE FREED BY THIS FUNCTION
 168  * addpkt:    Packet to be appended and automatically released,
 169  *            WILL BE FREED BY THIS FUNCTION.
 170  * expectlen: Packet's expected total length. This should be considered
 171  *            as a hint.
 172  * NB: Input packets will be destroyed after appending and cannot be used
 173  * after calling this function.
 174  * @return    The new appended packet.
 175  */
 176 struct cfpkt *cfpkt_append(struct cfpkt *dstpkt, struct cfpkt *addpkt,
 177                       u16 expectlen);
 178
 179 /*
 180  * cfpkt_split - Split a packet into two packets at the specified split point.
 181  * pkt: Packet to be split (will contain the first part of the data on exit)
 182  * pos: Position to split packet in two parts.
 183  * @return The new packet, containing the second part of the data.
 184  */
 185 struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos);
 186
 187 /*
 188  * Iteration function, iterates the packet buffers from start to end.
 189  *
 190  * Checksum iteration function used to iterate buffers
 191  * (we may have packets consisting of a chain of buffers)
 192  * pkt:       Packet to calculate checksum for
 193  * iter_func: Function pointer to iteration function
 194  * chks:      Checksum calculated so far.
 195  * buf:       Pointer to the buffer to checksum
 196  * len:       Length of buf.
 197  * data:      Initial checksum value.
 198  * @return    Checksum of buffer.
 199  */
 200
 201 int cfpkt_iterate(struct cfpkt *pkt,
 202                 u16 (*iter_func)(u16 chks, void *buf, u16 len),
 203                 u16 data);
 204
 205 /* Map from a "native" packet (e.g. Linux Socket Buffer) to a CAIF packet.
 206  *  dir - Direction indicating whether this packet is to be sent or received.
 207  *  nativepkt  - The native packet to be transformed to a CAIF packet
 208  *  @return The mapped CAIF Packet CFPKT.
 209  */
 210 struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt);
 211
 212 /* Map from a CAIF packet to a "native" packet (e.g. Linux Socket Buffer).
 213  *  pkt  - The CAIF packet to be transformed into a "native" packet.
 214  *  @return The native packet transformed from a CAIF packet.
 215  */
 216 void *cfpkt_tonative(struct cfpkt *pkt);
 217
 218 /*
 219  * Returns packet information for a packet.
 220  * pkt Packet to get info from;
 221  * @return Packet information
 222  */
 223 struct caif_payload_info *cfpkt_info(struct cfpkt *pkt);
 224
 225 /** cfpkt_set_prio - set priority for a CAIF packet.
 226  *
 227  * @pkt: The CAIF packet to be adjusted.
 228  * @prio: one of TC_PRIO_ constants.
 229  */
 230 void cfpkt_set_prio(struct cfpkt *pkt, int prio);
 231
 232 #endif                          /* CFPKT_H_ */