FreeRTOS/Common/ethernet/lwIP_132/src/api/netbuf.c

   1 /**
   2  * @file
   3  * Network buffer management
   4  *
   5  */
   6
   7 /*
   8  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without modification,
  12  * are permitted provided that the following conditions are met:
  13  *
  14  * 1. Redistributions of source code must retain the above copyright notice,
  15  *    this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright notice,
  17  *    this list of conditions and the following disclaimer in the documentation
  18  *    and/or other materials provided with the distribution.
  19  * 3. The name of the author may not be used to endorse or promote products
  20  *    derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  25  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  26  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  27  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  30  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  31  * OF SUCH DAMAGE.
  32  *
  33  * This file is part of the lwIP TCP/IP stack.
  34  *
  35  * Author: Adam Dunkels <adam@sics.se>
  36  *
  37  */
  38
  39 #include "lwip/opt.h"
  40
  41 #if LWIP_NETCONN /* don't build if not configured for use in lwipopts.h */
  42
  43 #include "lwip/netbuf.h"
  44 #include "lwip/memp.h"
  45
  46 #include <string.h>
  47
  48 /**
  49  * Create (allocate) and initialize a new netbuf.
  50  * The netbuf doesn't yet contain a packet buffer!
  51  *
  52  * @return a pointer to a new netbuf
  53  *         NULL on lack of memory
  54  */
  55 struct
  56 netbuf *netbuf_new(void)
  57 {
  58   struct netbuf *buf;
  59
  60   buf = memp_malloc(MEMP_NETBUF);
  61   if (buf != NULL) {
  62     buf->p = NULL;
  63     buf->ptr = NULL;
  64     buf->addr = NULL;
  65     buf->port = 0;
  66 #if LWIP_NETBUF_RECVINFO
  67     buf->toaddr = NULL;
  68     buf->toport = 0;
  69 #endif /* LWIP_NETBUF_RECVINFO */
  70     return buf;
  71   } else {
  72     return NULL;
  73   }
  74 }
  75
  76 /**
  77  * Deallocate a netbuf allocated by netbuf_new().
  78  *
  79  * @param buf pointer to a netbuf allocated by netbuf_new()
  80  */
  81 void
  82 netbuf_delete(struct netbuf *buf)
  83 {
  84   if (buf != NULL) {
  85     if (buf->p != NULL) {
  86       pbuf_free(buf->p);
  87       buf->p = buf->ptr = NULL;
  88     }
  89     memp_free(MEMP_NETBUF, buf);
  90   }
  91 }
  92
  93 /**
  94  * Allocate memory for a packet buffer for a given netbuf.
  95  *
  96  * @param buf the netbuf for which to allocate a packet buffer
  97  * @param size the size of the packet buffer to allocate
  98  * @return pointer to the allocated memory
  99  *         NULL if no memory could be allocated
 100  */
 101 void *
 102 netbuf_alloc(struct netbuf *buf, u16_t size)
 103 {
 104   LWIP_ERROR("netbuf_alloc: invalid buf", (buf != NULL), return NULL;);
 105
 106   /* Deallocate any previously allocated memory. */
 107   if (buf->p != NULL) {
 108     pbuf_free(buf->p);
 109   }
 110   buf->p = pbuf_alloc(PBUF_TRANSPORT, size, PBUF_RAM);
 111   if (buf->p == NULL) {
 112      return NULL;
 113   }
 114   LWIP_ASSERT("check that first pbuf can hold size",
 115              (buf->p->len >= size));
 116   buf->ptr = buf->p;
 117   return buf->p->payload;
 118 }
 119
 120 /**
 121  * Free the packet buffer included in a netbuf
 122  *
 123  * @param buf pointer to the netbuf which contains the packet buffer to free
 124  */
 125 void
 126 netbuf_free(struct netbuf *buf)
 127 {
 128   LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return;);
 129   if (buf->p != NULL) {
 130     pbuf_free(buf->p);
 131   }
 132   buf->p = buf->ptr = NULL;
 133 }
 134
 135 /**
 136  * Let a netbuf reference existing (non-volatile) data.
 137  *
 138  * @param buf netbuf which should reference the data
 139  * @param dataptr pointer to the data to reference
 140  * @param size size of the data
 141  * @return ERR_OK if data is referenced
 142  *         ERR_MEM if data couldn't be referenced due to lack of memory
 143  */
 144 err_t
 145 netbuf_ref(struct netbuf *buf, const void *dataptr, u16_t size)
 146 {
 147   LWIP_ERROR("netbuf_ref: invalid buf", (buf != NULL), return ERR_ARG;);
 148   if (buf->p != NULL) {
 149     pbuf_free(buf->p);
 150   }
 151   buf->p = pbuf_alloc(PBUF_TRANSPORT, 0, PBUF_REF);
 152   if (buf->p == NULL) {
 153     buf->ptr = NULL;
 154     return ERR_MEM;
 155   }
 156   buf->p->payload = (void*)dataptr;
 157   buf->p->len = buf->p->tot_len = size;
 158   buf->ptr = buf->p;
 159   return ERR_OK;
 160 }
 161
 162 /**
 163  * Chain one netbuf to another (@see pbuf_chain)
 164  *
 165  * @param head the first netbuf
 166  * @param tail netbuf to chain after head, freed by this function, may not be reference after returning
 167  */
 168 void
 169 netbuf_chain(struct netbuf *head, struct netbuf *tail)
 170 {
 171   LWIP_ERROR("netbuf_ref: invalid head", (head != NULL), return;);
 172   LWIP_ERROR("netbuf_chain: invalid tail", (tail != NULL), return;);
 173   pbuf_cat(head->p, tail->p);
 174   head->ptr = head->p;
 175   memp_free(MEMP_NETBUF, tail);
 176 }
 177
 178 /**
 179  * Get the data pointer and length of the data inside a netbuf.
 180  *
 181  * @param buf netbuf to get the data from
 182  * @param dataptr pointer to a void pointer where to store the data pointer
 183  * @param len pointer to an u16_t where the length of the data is stored
 184  * @return ERR_OK if the information was retreived,
 185  *         ERR_BUF on error.
 186  */
 187 err_t
 188 netbuf_data(struct netbuf *buf, void **dataptr, u16_t *len)
 189 {
 190   LWIP_ERROR("netbuf_data: invalid buf", (buf != NULL), return ERR_ARG;);
 191   LWIP_ERROR("netbuf_data: invalid dataptr", (dataptr != NULL), return ERR_ARG;);
 192   LWIP_ERROR("netbuf_data: invalid len", (len != NULL), return ERR_ARG;);
 193
 194   if (buf->ptr == NULL) {
 195     return ERR_BUF;
 196   }
 197   *dataptr = buf->ptr->payload;
 198   *len = buf->ptr->len;
 199   return ERR_OK;
 200 }
 201
 202 /**
 203  * Move the current data pointer of a packet buffer contained in a netbuf
 204  * to the next part.
 205  * The packet buffer itself is not modified.
 206  *
 207  * @param buf the netbuf to modify
 208  * @return -1 if there is no next part
 209  *         1  if moved to the next part but now there is no next part
 210  *         0  if moved to the next part and there are still more parts
 211  */
 212 s8_t
 213 netbuf_next(struct netbuf *buf)
 214 {
 215   LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return -1;);
 216   if (buf->ptr->next == NULL) {
 217     return -1;
 218   }
 219   buf->ptr = buf->ptr->next;
 220   if (buf->ptr->next == NULL) {
 221     return 1;
 222   }
 223   return 0;
 224 }
 225
 226 /**
 227  * Move the current data pointer of a packet buffer contained in a netbuf
 228  * to the beginning of the packet.
 229  * The packet buffer itself is not modified.
 230  *
 231  * @param buf the netbuf to modify
 232  */
 233 void
 234 netbuf_first(struct netbuf *buf)
 235 {
 236   LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return;);
 237   buf->ptr = buf->p;
 238 }
 239
 240 #endif /* LWIP_NETCONN */