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 (at) 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 = (struct netbuf *)memp_malloc(MEMP_NETBUF); 61 if (buf != NULL) { 62 buf->p = NULL; 63 buf->ptr = NULL; 64 ip_addr_set_any(&buf->addr); 65 buf->port = 0; 66 #if LWIP_NETBUF_RECVINFO || LWIP_CHECKSUM_ON_COPY 67 #if LWIP_CHECKSUM_ON_COPY 68 buf->flags = 0; 69 #endif /* LWIP_CHECKSUM_ON_COPY */ 70 buf->toport_chksum = 0; 71 #if LWIP_NETBUF_RECVINFO 72 ip_addr_set_any(&buf->toaddr); 73 #endif /* LWIP_NETBUF_RECVINFO */ 74 #endif /* LWIP_NETBUF_RECVINFO || LWIP_CHECKSUM_ON_COPY */ 75 return buf; 76 } else { 77 return NULL; 78 } 79 } 80 81 /** 82 * Deallocate a netbuf allocated by netbuf_new(). 83 * 84 * @param buf pointer to a netbuf allocated by netbuf_new() 85 */ 86 void 87 netbuf_delete(struct netbuf *buf) 88 { 89 if (buf != NULL) { 90 if (buf->p != NULL) { 91 pbuf_free(buf->p); 92 buf->p = buf->ptr = NULL; 93 } 94 memp_free(MEMP_NETBUF, buf); 95 } 96 } 97 98 /** 99 * Allocate memory for a packet buffer for a given netbuf. 100 * 101 * @param buf the netbuf for which to allocate a packet buffer 102 * @param size the size of the packet buffer to allocate 103 * @return pointer to the allocated memory 104 * NULL if no memory could be allocated 105 */ 106 void * 107 netbuf_alloc(struct netbuf *buf, u16_t size) 108 { 109 LWIP_ERROR("netbuf_alloc: invalid buf", (buf != NULL), return NULL;); 110 111 /* Deallocate any previously allocated memory. */ 112 if (buf->p != NULL) { 113 pbuf_free(buf->p); 114 } 115 buf->p = pbuf_alloc(PBUF_TRANSPORT, size, PBUF_RAM); 116 if (buf->p == NULL) { 117 return NULL; 118 } 119 LWIP_ASSERT("check that first pbuf can hold size", 120 (buf->p->len >= size)); 121 buf->ptr = buf->p; 122 return buf->p->payload; 123 } 124 125 /** 126 * Free the packet buffer included in a netbuf 127 * 128 * @param buf pointer to the netbuf which contains the packet buffer to free 129 */ 130 void 131 netbuf_free(struct netbuf *buf) 132 { 133 LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return;); 134 if (buf->p != NULL) { 135 pbuf_free(buf->p); 136 } 137 buf->p = buf->ptr = NULL; 138 } 139 140 /** 141 * Let a netbuf reference existing (non-volatile) data. 142 * 143 * @param buf netbuf which should reference the data 144 * @param dataptr pointer to the data to reference 145 * @param size size of the data 146 * @return ERR_OK if data is referenced 147 * ERR_MEM if data couldn't be referenced due to lack of memory 148 */ 149 err_t 150 netbuf_ref(struct netbuf *buf, const void *dataptr, u16_t size) 151 { 152 LWIP_ERROR("netbuf_ref: invalid buf", (buf != NULL), return ERR_ARG;); 153 if (buf->p != NULL) { 154 pbuf_free(buf->p); 155 } 156 buf->p = pbuf_alloc(PBUF_TRANSPORT, 0, PBUF_REF); 157 if (buf->p == NULL) { 158 buf->ptr = NULL; 159 return ERR_MEM; 160 } 161 buf->p->payload = (void*)dataptr; 162 buf->p->len = buf->p->tot_len = size; 163 buf->ptr = buf->p; 164 return ERR_OK; 165 } 166 167 /** 168 * Chain one netbuf to another (@see pbuf_chain) 169 * 170 * @param head the first netbuf 171 * @param tail netbuf to chain after head, freed by this function, may not be reference after returning 172 */ 173 void 174 netbuf_chain(struct netbuf *head, struct netbuf *tail) 175 { 176 LWIP_ERROR("netbuf_ref: invalid head", (head != NULL), return;); 177 LWIP_ERROR("netbuf_chain: invalid tail", (tail != NULL), return;); 178 pbuf_cat(head->p, tail->p); 179 head->ptr = head->p; 180 memp_free(MEMP_NETBUF, tail); 181 } 182 183 /** 184 * Get the data pointer and length of the data inside a netbuf. 185 * 186 * @param buf netbuf to get the data from 187 * @param dataptr pointer to a void pointer where to store the data pointer 188 * @param len pointer to an u16_t where the length of the data is stored 189 * @return ERR_OK if the information was retreived, 190 * ERR_BUF on error. 191 */ 192 err_t 193 netbuf_data(struct netbuf *buf, void **dataptr, u16_t *len) 194 { 195 LWIP_ERROR("netbuf_data: invalid buf", (buf != NULL), return ERR_ARG;); 196 LWIP_ERROR("netbuf_data: invalid dataptr", (dataptr != NULL), return ERR_ARG;); 197 LWIP_ERROR("netbuf_data: invalid len", (len != NULL), return ERR_ARG;); 198 199 if (buf->ptr == NULL) { 200 return ERR_BUF; 201 } 202 *dataptr = buf->ptr->payload; 203 *len = buf->ptr->len; 204 return ERR_OK; 205 } 206 207 /** 208 * Move the current data pointer of a packet buffer contained in a netbuf 209 * to the next part. 210 * The packet buffer itself is not modified. 211 * 212 * @param buf the netbuf to modify 213 * @return -1 if there is no next part 214 * 1 if moved to the next part but now there is no next part 215 * 0 if moved to the next part and there are still more parts 216 */ 217 s8_t 218 netbuf_next(struct netbuf *buf) 219 { 220 LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return -1;); 221 if (buf->ptr->next == NULL) { 222 return -1; 223 } 224 buf->ptr = buf->ptr->next; 225 if (buf->ptr->next == NULL) { 226 return 1; 227 } 228 return 0; 229 } 230 231 /** 232 * Move the current data pointer of a packet buffer contained in a netbuf 233 * to the beginning of the packet. 234 * The packet buffer itself is not modified. 235 * 236 * @param buf the netbuf to modify 237 */ 238 void 239 netbuf_first(struct netbuf *buf) 240 { 241 LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return;); 242 buf->ptr = buf->p; 243 } 244 245 #endif /* LWIP_NETCONN */ 246
