mirror of
https://github.com/obgm/libcoap.git
synced 2026-11-07 18:12:55 +03:00
jcmichelou
bcfd7a0753
Make coap_pdu-t independent of the header style. Use C99 sized types when applicable. Use transaction ids in host byte order in the library. Make coap_pdu_t payload storage grow on demand. Add parsing and encoding of PDUs with UDP or TCP style headers. Adapt examples and unit tests to the new PDU format.
127 lines
2.6 KiB
C
127 lines
2.6 KiB
C
/*
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* prng.h -- Pseudo Random Numbers
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*
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* Copyright (C) 2010-2011 Olaf Bergmann <bergmann@tzi.org>
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*
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* This file is part of the CoAP library libcoap. Please see README for terms
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* of use.
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*/
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/**
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* @file prng.h
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* @brief Pseudo Random Numbers
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*/
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#ifndef _COAP_PRNG_H_
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#define _COAP_PRNG_H_
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/**
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* @defgroup prng Pseudo Random Numbers
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* @{
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*/
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#if defined(WITH_CONTIKI)
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#include <string.h>
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/**
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* Fills \p buf with \p len random bytes. This is the default implementation for
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* prng(). You might want to change prng() to use a better PRNG on your specific
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* platform.
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*/
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COAP_STATIC_INLINE int
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contiki_prng_impl(unsigned char *buf, size_t len) {
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uint16_t v = random_rand();
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while (len > sizeof(v)) {
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memcpy(buf, &v, sizeof(v));
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len -= sizeof(v);
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buf += sizeof(v);
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v = random_rand();
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}
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memcpy(buf, &v, len);
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return 1;
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}
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#define prng(Buf,Length) contiki_prng_impl((Buf), (Length))
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#define prng_init(Value) random_init((uint16_t)(Value))
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#elif defined(WITH_LWIP) && defined(LWIP_RAND)
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COAP_STATIC_INLINE int
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lwip_prng_impl(unsigned char *buf, size_t len) {
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u32_t v = LWIP_RAND();
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while (len > sizeof(v)) {
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memcpy(buf, &v, sizeof(v));
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len -= sizeof(v);
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buf += sizeof(v);
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v = LWIP_RAND();
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}
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memcpy(buf, &v, len);
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return 1;
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}
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#define prng(Buf,Length) lwip_prng_impl((Buf), (Length))
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#define prng_init(Value)
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#elif defined(_WIN32)
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#define prng_init(Value)
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errno_t __cdecl rand_s( _Out_ unsigned int* _RandomValue );
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/**
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* Fills \p buf with \p len random bytes. This is the default implementation for
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* prng(). You might want to change prng() to use a better PRNG on your specific
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* platform.
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*/
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COAP_STATIC_INLINE int
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coap_prng_impl( unsigned char *buf, size_t len ) {
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while ( len != 0 ) {
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uint32_t r = 0;
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size_t i;
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if ( rand_s( &r ) != 0 )
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return 0;
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for ( i = 0; i < len && i < 4; i++ ) {
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*buf++ = (uint8_t)r;
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r >>= 8;
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}
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len -= i;
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}
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return 1;
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}
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#else
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#include <stdlib.h>
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/**
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* Fills \p buf with \p len random bytes. This is the default implementation for
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* prng(). You might want to change prng() to use a better PRNG on your specific
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* platform.
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*/
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COAP_STATIC_INLINE int
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coap_prng_impl( unsigned char *buf, size_t len ) {
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while ( len-- )
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*buf++ = rand() & 0xFF;
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return 1;
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}
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#endif
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#ifndef prng
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/**
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* Fills \p Buf with \p Length bytes of random data.
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*
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* @hideinitializer
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*/
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#define prng(Buf,Length) coap_prng_impl((Buf), (Length))
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#endif
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#ifndef prng_init
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/**
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* Called to set the PRNG seed. You may want to re-define this to allow for a
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* better PRNG.
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*
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* @hideinitializer
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*/
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#define prng_init(Value) srand((unsigned long)(Value))
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#endif
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/** @} */
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#endif /* _COAP_PRNG_H_ */
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