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