Files
libcoap/include/coap/block.h
T
Jon Shallow b4fc68c554 include/coap/*.h: Remove cast-qual compiler warnings
Commented out coap_opt_block_set_m() as it is not used anywhere, and needs
to get rewritten if needed.

Removed / changed references to coap_opt_const_value()

Created a new struct coap_str_const_t to handle const parameters
Add in 2 new functions to create / delete the new string type
coap_new_str_const()
coap_delete_str_const()
Added in coap_make_str_const() to help create the necessary string equivalents
of the ascii test string.  Note that the byte array must be in the
local scope.

Make coap_string_equal() a macro to handle differing string types

Made uri_path a pointer in coap_resource_t
Made name and value a pointer in coap_attribute_t

Reasoning behind this was triggerred by test t_wellknown3() creating a
number of resources, all using the same string buffer, so they all ended up
with the same uri-path (last update to uri-path).  In the days of hashing
uri-path for the lookup would have worked, but the wrong uri-path
presented from the resource.  Now we always allocate uri-path if
application does not want it freed off - and always free it off at time
or resource removal.  The same is also true for coap_add_attr().

Updated coap_resource_init(), coap_add_attr() and coap_find_attr() to
pass in string parameters, rather than use a pointer to data and a length.

Where appropriate

Replace 'unsigned char' with 'const uint8_t'
Replace 'str' with 'coap_str_const_t'
Replace 'str' with 'coap_string_t'
Prefix with 'const' some type casts
Remove 'const' prefix from some type casts
2018-05-25 16:37:05 +01:00

139 lines
4.5 KiB
C

/*
* block.h -- block transfer
*
* Copyright (C) 2010-2012,2014-2015 Olaf Bergmann <bergmann@tzi.org>
*
* This file is part of the CoAP library libcoap. Please see README for terms
* of use.
*/
#ifndef _COAP_BLOCK_H_
#define _COAP_BLOCK_H_
#include "encode.h"
#include "option.h"
#include "pdu.h"
/**
* @defgroup block Block Transfer
* @{
*/
#ifndef COAP_MAX_BLOCK_SZX
/**
* The largest value for the SZX component in a Block option.
*/
#define COAP_MAX_BLOCK_SZX 6
#endif /* COAP_MAX_BLOCK_SZX */
/**
* Structure of Block options.
*/
typedef struct {
unsigned int num; /**< block number */
unsigned int m:1; /**< 1 if more blocks follow, 0 otherwise */
unsigned int szx:3; /**< block size */
} coap_block_t;
/**
* Returns the value of the least significant byte of a Block option @p opt.
* For zero-length options (i.e. num == m == szx == 0), COAP_OPT_BLOCK_LAST
* returns @c NULL.
*/
#define COAP_OPT_BLOCK_LAST(opt) \
(coap_opt_length(opt) ? (coap_opt_value(opt) + (coap_opt_length(opt)-1)) : 0)
/** Returns the value of the More-bit of a Block option @p opt. */
#define COAP_OPT_BLOCK_MORE(opt) \
(coap_opt_length(opt) ? (*COAP_OPT_BLOCK_LAST(opt) & 0x08) : 0)
/** Returns the value of the SZX-field of a Block option @p opt. */
#define COAP_OPT_BLOCK_SZX(opt) \
(coap_opt_length(opt) ? (*COAP_OPT_BLOCK_LAST(opt) & 0x07) : 0)
/**
* Returns the value of field @c num in the given block option @p block_opt.
*/
unsigned int coap_opt_block_num(const coap_opt_t *block_opt);
/**
* Checks if more than @p num blocks are required to deliver @p data_len
* bytes of data for a block size of 1 << (@p szx + 4).
*/
COAP_STATIC_INLINE int
coap_more_blocks(size_t data_len, unsigned int num, uint16_t szx) {
return ((num+1) << (szx + 4)) < data_len;
}
#if 0
/** Sets the More-bit in @p block_opt */
COAP_STATIC_INLINE void
coap_opt_block_set_m(coap_opt_t *block_opt, int m) {
if (m)
*(coap_opt_value(block_opt) + (coap_opt_length(block_opt) - 1)) |= 0x08;
else
*(coap_opt_value(block_opt) + (coap_opt_length(block_opt) - 1)) &= ~0x08;
}
#endif
/**
* Initializes @p block from @p pdu. @p type must be either COAP_OPTION_BLOCK1
* or COAP_OPTION_BLOCK2. When option @p type was found in @p pdu, @p block is
* initialized with values from this option and the function returns the value
* @c 1. Otherwise, @c 0 is returned.
*
* @param pdu The pdu to search for option @p type.
* @param type The option to search for (must be COAP_OPTION_BLOCK1 or
* COAP_OPTION_BLOCK2).
* @param block The block structure to initilize.
*
* @return @c 1 on success, @c 0 otherwise.
*/
int coap_get_block(coap_pdu_t *pdu, uint16_t type, coap_block_t *block);
/**
* Writes a block option of type @p type to message @p pdu. If the requested
* block size is too large to fit in @p pdu, it is reduced accordingly. An
* exception is made for the final block when less space is required. The actual
* length of the resource is specified in @p data_length.
*
* This function may change *block to reflect the values written to @p pdu. As
* the function takes into consideration the remaining space @p pdu, no more
* options should be added after coap_write_block_opt() has returned.
*
* @param block The block structure to use. On return, this object is
* updated according to the values that have been written to
* @p pdu.
* @param type COAP_OPTION_BLOCK1 or COAP_OPTION_BLOCK2.
* @param pdu The message where the block option should be written.
* @param data_length The length of the actual data that will be added the @p
* pdu by calling coap_add_block().
*
* @return @c 1 on success, or a negative value on error.
*/
int coap_write_block_opt(coap_block_t *block,
uint16_t type,
coap_pdu_t *pdu,
size_t data_length);
/**
* Adds the @p block_num block of size 1 << (@p block_szx + 4) from source @p
* data to @p pdu.
*
* @param pdu The message to add the block.
* @param len The length of @p data.
* @param data The source data to fill the block with.
* @param block_num The actual block number.
* @param block_szx Encoded size of block @p block_number.
*
* @return @c 1 on success, @c 0 otherwise.
*/
int coap_add_block(coap_pdu_t *pdu,
unsigned int len,
const uint8_t *data,
unsigned int block_num,
unsigned char block_szx);
/**@}*/
#endif /* _COAP_BLOCK_H_ */