FreeRTOS/Common/ethernet/lwIP/include/lwip/pbuf.h

   1 /*
   2  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without modification,
   6  * are permitted provided that the following conditions are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright notice,
   9  *    this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright notice,
  11  *    this list of conditions and the following disclaimer in the documentation
  12  *    and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  19  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  21  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  24  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  25  * OF SUCH DAMAGE.
  26  *
  27  * This file is part of the lwIP TCP/IP stack.
  28  *
  29  * Author: Adam Dunkels <adam@sics.se>
  30  *
  31  */
  32
  33 #ifndef __LWIP_PBUF_H__
  34 #define __LWIP_PBUF_H__
  35
  36 #include "arch/cc.h"
  37
  38
  39 #define PBUF_TRANSPORT_HLEN 20
  40 #define PBUF_IP_HLEN        20
  41
  42 typedef enum {
  43   PBUF_TRANSPORT,
  44   PBUF_IP,
  45   PBUF_LINK,
  46   PBUF_RAW
  47 } pbuf_layer;
  48
  49 typedef enum {
  50   PBUF_RAM,
  51   PBUF_ROM,
  52   PBUF_REF,
  53   PBUF_POOL
  54 } pbuf_flag;
  55
  56 /* Definitions for the pbuf flag field. These are NOT the flags that
  57  * are passed to pbuf_alloc(). */
  58 #define PBUF_FLAG_RAM   0x00U    /* Flags that pbuf data is stored in RAM */
  59 #define PBUF_FLAG_ROM   0x01U    /* Flags that pbuf data is stored in ROM */
  60 #define PBUF_FLAG_POOL  0x02U    /* Flags that the pbuf comes from the pbuf pool */
  61 #define PBUF_FLAG_REF   0x04U    /* Flags thet the pbuf payload refers to RAM */
  62
  63 /** indicates this packet was broadcast on the link */
  64 #define PBUF_FLAG_LINK_BROADCAST 0x80U
  65
  66 struct pbuf {
  67   /** next pbuf in singly linked pbuf chain */
  68   struct pbuf *next;
  69
  70   /** pointer to the actual data in the buffer */
  71   void *payload;
  72
  73   /**
  74    * total length of this buffer and all next buffers in chain
  75    * belonging to the same packet.
  76    *
  77    * For non-queue packet chains this is the invariant:
  78    * p->tot_len == p->len + (p->next? p->next->tot_len: 0)
  79    */
  80   u16_t tot_len;
  81
  82   /** length of this buffer */
  83   u16_t len;
  84
  85   /** flags telling the type of pbuf, see PBUF_FLAG_ */
  86   u16_t flags;
  87
  88   /**
  89    * the reference count always equals the number of pointers
  90    * that refer to this pbuf. This can be pointers from an application,
  91    * the stack itself, or pbuf->next pointers from a chain.
  92    */
  93   u16_t ref;
  94
  95 };
  96
  97 void pbuf_init(void);
  98
  99 struct pbuf *pbuf_alloc(pbuf_layer l, u16_t size, pbuf_flag flag);
 100 void pbuf_realloc(struct pbuf *p, u16_t size);
 101 u8_t pbuf_header(struct pbuf *p, s16_t header_size);
 102 void pbuf_ref(struct pbuf *p);
 103 void pbuf_ref_chain(struct pbuf *p);
 104 u8_t pbuf_free(struct pbuf *p);
 105 u8_t pbuf_clen(struct pbuf *p);
 106 void pbuf_cat(struct pbuf *h, struct pbuf *t);
 107 void pbuf_chain(struct pbuf *h, struct pbuf *t);
 108 struct pbuf *pbuf_take(struct pbuf *f);
 109 struct pbuf *pbuf_dechain(struct pbuf *p);
 110 void pbuf_queue(struct pbuf *p, struct pbuf *n);
 111 struct pbuf * pbuf_dequeue(struct pbuf *p);
 112
 113 #endif /* __LWIP_PBUF_H__ */