xref: /linux/include/net/caif/cfpkt.h (revision c4c11dd160a8cc98f402c4e12f94b1572e822ffd)
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 /*
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  * Returns packet information for a packet.
193  * pkt Packet to get info from;
194  * @return Packet information
195  */
196 struct caif_payload_info *cfpkt_info(struct cfpkt *pkt);
197 
198 /** cfpkt_set_prio - set priority for a CAIF packet.
199  *
200  * @pkt: The CAIF packet to be adjusted.
201  * @prio: one of TC_PRIO_ constants.
202  */
203 void cfpkt_set_prio(struct cfpkt *pkt, int prio);
204 
205 #endif				/* CFPKT_H_ */
206