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Overview Power Industry Serial Device Server Programmable Gateways Serial/Ethernet Gateway XNUT-100 CAN/Ethernet Gateway XNUT-105 Ethernet CPU Boards Shop Information and Support

Network Buffer [Network device drivers.] Collaboration diagram for Network Buffer: Detailed Description Network buffer support. The network buffer handling is designed to make life easy when it comes to handling ISO-layered communications. By this we're thinking about communications structures that are hierarchically organized. The idea is that network buffer structures are allocated every time a new packet is either received or ready for sending. The various fields of the network buffer are then handled by matching layers within the appropriate protocol stack. Linked list of NETBUF structures: Data Structures struct   _NBDATA   Data part of a network buffer structure. More... struct   _NETBUF   Network buffer structure. More... struct   _NBDATA   Data part of a network buffer structure. More... struct   _NETBUF   Network buffer structure. More... Defines #define  NBAF_DATALINK   Datalink buffer allocated flag. #define  NBAF_NETWORK   Network buffer allocated flag. #define  NBAF_TRANSPORT   Transport buffer allocated flag. #define  NBAF_APPLICATION   Application buffer allocated flag. #define  NBAF_ALL   Masks allocated buffer flags flag. Typedefs typedef _NETBUF  NETBUF   Network buffer type. typedef _NBDATA  NBDATA   Network buffer data type. Functions NETBUF *  NutNetBufAlloc (NETBUF *nb, u_char type, u_short size)   Allocate or re-allocate a network buffer part. NETBUF *  NutNetBufClone (NETBUF *nb)   Create a copy of an existing network buffer structure. int  NutNetBufFree (NETBUF *nb)   Release a network buffer structure. Function Documentation NETBUF* NutNetBufAlloc (  NETBUF *  nb, u_char  type, u_short  size )    Allocate or re-allocate a network buffer part. Parameters: nb  Points to an existing network buffer structure or NULL, if a new structure should be created. An existing buffer must not be used any further if this function returns a null pointer. type  Part of the buffer to be allocated. This can be any of the following: NBAF_DATALINK NBAF_NETWORK NBAF_TRANSPORT NBAF_APPLICATION size  Size of the part to be allocated. Returns: Pointer to the allocated network buffer structure. A null pointer is returned if not enough memory is available and the whole structure is released. NETBUF* NutNetBufClone (  NETBUF *  nb  )    Create a copy of an existing network buffer structure. Parameters: nb  Points to an existing network buffer structure, previously allocated by NutNetBufAlloc(). Returns: Pointer to a newly allocated copy. int NutNetBufFree (  NETBUF *  nb  )    Release a network buffer structure. Returns all memory previously allocated by a network buffer to the available heap space. Parameters: nb  Points to an existing network buffer structure, previously allocated by NutNetBufAlloc(). Returns: 0 if successfull or -1 if the structure contains previously released memory space.

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