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Dependents: TYBLE16_simple_data_logger TYBLE16_MP3_Air
lwip_netbuf.c
00001 /** 00002 * @file 00003 * Network buffer management 00004 * 00005 * @defgroup netbuf Network buffers 00006 * @ingroup netconn 00007 * Network buffer descriptor for @ref netconn. Based on @ref pbuf internally 00008 * to avoid copying data around.\n 00009 * Buffers must not be shared accross multiple threads, all functions except 00010 * netbuf_new() and netbuf_delete() are not thread-safe. 00011 */ 00012 00013 /* 00014 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 00015 * All rights reserved. 00016 * 00017 * Redistribution and use in source and binary forms, with or without modification, 00018 * are permitted provided that the following conditions are met: 00019 * 00020 * 1. Redistributions of source code must retain the above copyright notice, 00021 * this list of conditions and the following disclaimer. 00022 * 2. Redistributions in binary form must reproduce the above copyright notice, 00023 * this list of conditions and the following disclaimer in the documentation 00024 * and/or other materials provided with the distribution. 00025 * 3. The name of the author may not be used to endorse or promote products 00026 * derived from this software without specific prior written permission. 00027 * 00028 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 00029 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00030 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 00031 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00032 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 00033 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00034 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00035 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 00036 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 00037 * OF SUCH DAMAGE. 00038 * 00039 * This file is part of the lwIP TCP/IP stack. 00040 * 00041 * Author: Adam Dunkels <adam@sics.se> 00042 * 00043 */ 00044 00045 #include "lwip/opt.h" 00046 00047 #if LWIP_NETCONN /* don't build if not configured for use in lwipopts.h */ 00048 00049 #include "lwip/netbuf.h" 00050 #include "lwip/memp.h" 00051 00052 #include <string.h> 00053 00054 /** 00055 * @ingroup netbuf 00056 * Create (allocate) and initialize a new netbuf. 00057 * The netbuf doesn't yet contain a packet buffer! 00058 * 00059 * @return a pointer to a new netbuf 00060 * NULL on lack of memory 00061 */ 00062 struct 00063 netbuf *netbuf_new(void) 00064 { 00065 struct netbuf *buf; 00066 00067 buf = (struct netbuf *)memp_malloc(MEMP_NETBUF); 00068 if (buf != NULL) { 00069 memset(buf, 0, sizeof(struct netbuf)); 00070 } 00071 return buf; 00072 } 00073 00074 /** 00075 * @ingroup netbuf 00076 * Deallocate a netbuf allocated by netbuf_new(). 00077 * 00078 * @param buf pointer to a netbuf allocated by netbuf_new() 00079 */ 00080 void 00081 netbuf_delete(struct netbuf *buf) 00082 { 00083 if (buf != NULL) { 00084 if (buf->p != NULL) { 00085 pbuf_free(buf->p); 00086 buf->p = buf->ptr = NULL; 00087 } 00088 memp_free(MEMP_NETBUF, buf); 00089 } 00090 } 00091 00092 /** 00093 * @ingroup netbuf 00094 * Allocate memory for a packet buffer for a given netbuf. 00095 * 00096 * @param buf the netbuf for which to allocate a packet buffer 00097 * @param size the size of the packet buffer to allocate 00098 * @return pointer to the allocated memory 00099 * NULL if no memory could be allocated 00100 */ 00101 void * 00102 netbuf_alloc(struct netbuf *buf, u16_t size) 00103 { 00104 LWIP_ERROR("netbuf_alloc: invalid buf", (buf != NULL), return NULL;); 00105 00106 /* Deallocate any previously allocated memory. */ 00107 if (buf->p != NULL) { 00108 pbuf_free(buf->p); 00109 } 00110 buf->p = pbuf_alloc(PBUF_TRANSPORT, size, PBUF_RAM); 00111 if (buf->p == NULL) { 00112 return NULL; 00113 } 00114 LWIP_ASSERT("check that first pbuf can hold size", 00115 (buf->p->len >= size)); 00116 buf->ptr = buf->p; 00117 return buf->p->payload; 00118 } 00119 00120 /** 00121 * @ingroup netbuf 00122 * Free the packet buffer included in a netbuf 00123 * 00124 * @param buf pointer to the netbuf which contains the packet buffer to free 00125 */ 00126 void 00127 netbuf_free(struct netbuf *buf) 00128 { 00129 LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return;); 00130 if (buf->p != NULL) { 00131 pbuf_free(buf->p); 00132 } 00133 buf->p = buf->ptr = NULL; 00134 #if LWIP_CHECKSUM_ON_COPY 00135 buf->flags = 0; 00136 buf->toport_chksum = 0; 00137 #endif /* LWIP_CHECKSUM_ON_COPY */ 00138 } 00139 00140 /** 00141 * @ingroup netbuf 00142 * Let a netbuf reference existing (non-volatile) data. 00143 * 00144 * @param buf netbuf which should reference the data 00145 * @param dataptr pointer to the data to reference 00146 * @param size size of the data 00147 * @return ERR_OK if data is referenced 00148 * ERR_MEM if data couldn't be referenced due to lack of memory 00149 */ 00150 err_t 00151 netbuf_ref(struct netbuf *buf, const void *dataptr, u16_t size) 00152 { 00153 LWIP_ERROR("netbuf_ref: invalid buf", (buf != NULL), return ERR_ARG;); 00154 if (buf->p != NULL) { 00155 pbuf_free(buf->p); 00156 } 00157 buf->p = pbuf_alloc(PBUF_TRANSPORT, 0, PBUF_REF); 00158 if (buf->p == NULL) { 00159 buf->ptr = NULL; 00160 return ERR_MEM; 00161 } 00162 ((struct pbuf_rom *)buf->p)->payload = dataptr; 00163 buf->p->len = buf->p->tot_len = size; 00164 buf->ptr = buf->p; 00165 return ERR_OK; 00166 } 00167 00168 /** 00169 * @ingroup netbuf 00170 * Chain one netbuf to another (@see pbuf_chain) 00171 * 00172 * @param head the first netbuf 00173 * @param tail netbuf to chain after head, freed by this function, may not be reference after returning 00174 */ 00175 void 00176 netbuf_chain(struct netbuf *head, struct netbuf *tail) 00177 { 00178 LWIP_ERROR("netbuf_chain: invalid head", (head != NULL), return;); 00179 LWIP_ERROR("netbuf_chain: invalid tail", (tail != NULL), return;); 00180 pbuf_cat(head->p, tail->p); 00181 head->ptr = head->p; 00182 memp_free(MEMP_NETBUF, tail); 00183 } 00184 00185 /** 00186 * @ingroup netbuf 00187 * Get the data pointer and length of the data inside a netbuf. 00188 * 00189 * @param buf netbuf to get the data from 00190 * @param dataptr pointer to a void pointer where to store the data pointer 00191 * @param len pointer to an u16_t where the length of the data is stored 00192 * @return ERR_OK if the information was retrieved, 00193 * ERR_BUF on error. 00194 */ 00195 err_t 00196 netbuf_data(struct netbuf *buf, void **dataptr, u16_t *len) 00197 { 00198 LWIP_ERROR("netbuf_data: invalid buf", (buf != NULL), return ERR_ARG;); 00199 LWIP_ERROR("netbuf_data: invalid dataptr", (dataptr != NULL), return ERR_ARG;); 00200 LWIP_ERROR("netbuf_data: invalid len", (len != NULL), return ERR_ARG;); 00201 00202 if (buf->ptr == NULL) { 00203 return ERR_BUF; 00204 } 00205 *dataptr = buf->ptr->payload; 00206 *len = buf->ptr->len; 00207 return ERR_OK; 00208 } 00209 00210 /** 00211 * @ingroup netbuf 00212 * Move the current data pointer of a packet buffer contained in a netbuf 00213 * to the next part. 00214 * The packet buffer itself is not modified. 00215 * 00216 * @param buf the netbuf to modify 00217 * @return -1 if there is no next part 00218 * 1 if moved to the next part but now there is no next part 00219 * 0 if moved to the next part and there are still more parts 00220 */ 00221 s8_t 00222 netbuf_next(struct netbuf *buf) 00223 { 00224 LWIP_ERROR("netbuf_next: invalid buf", (buf != NULL), return -1;); 00225 if (buf->ptr->next == NULL) { 00226 return -1; 00227 } 00228 buf->ptr = buf->ptr->next; 00229 if (buf->ptr->next == NULL) { 00230 return 1; 00231 } 00232 return 0; 00233 } 00234 00235 /** 00236 * @ingroup netbuf 00237 * Move the current data pointer of a packet buffer contained in a netbuf 00238 * to the beginning of the packet. 00239 * The packet buffer itself is not modified. 00240 * 00241 * @param buf the netbuf to modify 00242 */ 00243 void 00244 netbuf_first(struct netbuf *buf) 00245 { 00246 LWIP_ERROR("netbuf_first: invalid buf", (buf != NULL), return;); 00247 buf->ptr = buf->p; 00248 } 00249 00250 #endif /* LWIP_NETCONN */
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