BadVPN – Blame information for rev 1
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1 | office | 1 | /** |
2 | * @file |
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3 | * Network buffer management |
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4 | * |
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5 | * @defgroup netbuf Network buffers |
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6 | * @ingroup netconn |
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7 | * Network buffer descriptor for @ref netconn. Based on @ref pbuf internally |
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8 | * to avoid copying data around.\n |
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9 | * Buffers must not be shared accross multiple threads, all functions except |
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10 | * netbuf_new() and netbuf_delete() are not thread-safe. |
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11 | */ |
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12 | |||
13 | /* |
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14 | * Copyright (c) 2001-2004 Swedish Institute of Computer Science. |
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15 | * All rights reserved. |
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16 | * |
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17 | * Redistribution and use in source and binary forms, with or without modification, |
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18 | * are permitted provided that the following conditions are met: |
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19 | * |
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20 | * 1. Redistributions of source code must retain the above copyright notice, |
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21 | * this list of conditions and the following disclaimer. |
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22 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
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23 | * this list of conditions and the following disclaimer in the documentation |
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24 | * and/or other materials provided with the distribution. |
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25 | * 3. The name of the author may not be used to endorse or promote products |
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26 | * derived from this software without specific prior written permission. |
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27 | * |
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28 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
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29 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
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30 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT |
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31 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
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32 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT |
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33 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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34 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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35 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
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36 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY |
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37 | * OF SUCH DAMAGE. |
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38 | * |
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39 | * This file is part of the lwIP TCP/IP stack. |
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40 | * |
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41 | * Author: Adam Dunkels <adam@sics.se> |
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42 | * |
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43 | */ |
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44 | |||
45 | #include "lwip/opt.h" |
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46 | |||
47 | #if LWIP_NETCONN /* don't build if not configured for use in lwipopts.h */ |
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48 | |||
49 | #include "lwip/netbuf.h" |
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50 | #include "lwip/memp.h" |
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51 | |||
52 | #include <string.h> |
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53 | |||
54 | /** |
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55 | * @ingroup netbuf |
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56 | * Create (allocate) and initialize a new netbuf. |
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57 | * The netbuf doesn't yet contain a packet buffer! |
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58 | * |
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59 | * @return a pointer to a new netbuf |
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60 | * NULL on lack of memory |
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61 | */ |
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62 | struct |
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63 | netbuf *netbuf_new(void) |
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64 | { |
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65 | struct netbuf *buf; |
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66 | |||
67 | buf = (struct netbuf *)memp_malloc(MEMP_NETBUF); |
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68 | if (buf != NULL) { |
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69 | memset(buf, 0, sizeof(struct netbuf)); |
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70 | } |
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71 | return buf; |
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72 | } |
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73 | |||
74 | /** |
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75 | * @ingroup netbuf |
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76 | * Deallocate a netbuf allocated by netbuf_new(). |
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77 | * |
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78 | * @param buf pointer to a netbuf allocated by netbuf_new() |
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79 | */ |
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80 | void |
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81 | netbuf_delete(struct netbuf *buf) |
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82 | { |
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83 | if (buf != NULL) { |
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84 | if (buf->p != NULL) { |
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85 | pbuf_free(buf->p); |
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86 | buf->p = buf->ptr = NULL; |
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87 | } |
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88 | memp_free(MEMP_NETBUF, buf); |
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89 | } |
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90 | } |
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91 | |||
92 | /** |
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93 | * @ingroup netbuf |
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94 | * Allocate memory for a packet buffer for a given netbuf. |
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95 | * |
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96 | * @param buf the netbuf for which to allocate a packet buffer |
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97 | * @param size the size of the packet buffer to allocate |
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98 | * @return pointer to the allocated memory |
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99 | * NULL if no memory could be allocated |
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100 | */ |
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101 | void * |
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102 | netbuf_alloc(struct netbuf *buf, u16_t size) |
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103 | { |
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104 | LWIP_ERROR("netbuf_alloc: invalid buf", (buf != NULL), return NULL;); |
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105 | |||
106 | /* Deallocate any previously allocated memory. */ |
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107 | if (buf->p != NULL) { |
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108 | pbuf_free(buf->p); |
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109 | } |
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110 | buf->p = pbuf_alloc(PBUF_TRANSPORT, size, PBUF_RAM); |
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111 | if (buf->p == NULL) { |
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112 | return NULL; |
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113 | } |
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114 | LWIP_ASSERT("check that first pbuf can hold size", |
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115 | (buf->p->len >= size)); |
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116 | buf->ptr = buf->p; |
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117 | return buf->p->payload; |
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118 | } |
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119 | |||
120 | /** |
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121 | * @ingroup netbuf |
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122 | * Free the packet buffer included in a netbuf |
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123 | * |
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124 | * @param buf pointer to the netbuf which contains the packet buffer to free |
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125 | */ |
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126 | void |
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127 | netbuf_free(struct netbuf *buf) |
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128 | { |
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129 | LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return;); |
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130 | if (buf->p != NULL) { |
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131 | pbuf_free(buf->p); |
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132 | } |
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133 | buf->p = buf->ptr = NULL; |
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134 | #if LWIP_CHECKSUM_ON_COPY |
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135 | buf->flags = 0; |
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136 | buf->toport_chksum = 0; |
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137 | #endif /* LWIP_CHECKSUM_ON_COPY */ |
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138 | } |
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139 | |||
140 | /** |
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141 | * @ingroup netbuf |
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142 | * Let a netbuf reference existing (non-volatile) data. |
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143 | * |
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144 | * @param buf netbuf which should reference the data |
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145 | * @param dataptr pointer to the data to reference |
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146 | * @param size size of the data |
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147 | * @return ERR_OK if data is referenced |
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148 | * ERR_MEM if data couldn't be referenced due to lack of memory |
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149 | */ |
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150 | err_t |
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151 | netbuf_ref(struct netbuf *buf, const void *dataptr, u16_t size) |
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152 | { |
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153 | LWIP_ERROR("netbuf_ref: invalid buf", (buf != NULL), return ERR_ARG;); |
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154 | if (buf->p != NULL) { |
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155 | pbuf_free(buf->p); |
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156 | } |
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157 | buf->p = pbuf_alloc(PBUF_TRANSPORT, 0, PBUF_REF); |
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158 | if (buf->p == NULL) { |
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159 | buf->ptr = NULL; |
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160 | return ERR_MEM; |
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161 | } |
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162 | ((struct pbuf_rom *)buf->p)->payload = dataptr; |
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163 | buf->p->len = buf->p->tot_len = size; |
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164 | buf->ptr = buf->p; |
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165 | return ERR_OK; |
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166 | } |
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167 | |||
168 | /** |
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169 | * @ingroup netbuf |
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170 | * Chain one netbuf to another (@see pbuf_chain) |
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171 | * |
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172 | * @param head the first netbuf |
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173 | * @param tail netbuf to chain after head, freed by this function, may not be reference after returning |
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174 | */ |
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175 | void |
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176 | netbuf_chain(struct netbuf *head, struct netbuf *tail) |
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177 | { |
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178 | LWIP_ERROR("netbuf_chain: invalid head", (head != NULL), return;); |
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179 | LWIP_ERROR("netbuf_chain: invalid tail", (tail != NULL), return;); |
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180 | pbuf_cat(head->p, tail->p); |
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181 | head->ptr = head->p; |
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182 | memp_free(MEMP_NETBUF, tail); |
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183 | } |
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184 | |||
185 | /** |
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186 | * @ingroup netbuf |
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187 | * Get the data pointer and length of the data inside a netbuf. |
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188 | * |
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189 | * @param buf netbuf to get the data from |
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190 | * @param dataptr pointer to a void pointer where to store the data pointer |
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191 | * @param len pointer to an u16_t where the length of the data is stored |
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192 | * @return ERR_OK if the information was retrieved, |
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193 | * ERR_BUF on error. |
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194 | */ |
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195 | err_t |
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196 | netbuf_data(struct netbuf *buf, void **dataptr, u16_t *len) |
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197 | { |
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198 | LWIP_ERROR("netbuf_data: invalid buf", (buf != NULL), return ERR_ARG;); |
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199 | LWIP_ERROR("netbuf_data: invalid dataptr", (dataptr != NULL), return ERR_ARG;); |
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200 | LWIP_ERROR("netbuf_data: invalid len", (len != NULL), return ERR_ARG;); |
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201 | |||
202 | if (buf->ptr == NULL) { |
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203 | return ERR_BUF; |
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204 | } |
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205 | *dataptr = buf->ptr->payload; |
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206 | *len = buf->ptr->len; |
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207 | return ERR_OK; |
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208 | } |
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209 | |||
210 | /** |
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211 | * @ingroup netbuf |
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212 | * Move the current data pointer of a packet buffer contained in a netbuf |
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213 | * to the next part. |
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214 | * The packet buffer itself is not modified. |
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215 | * |
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216 | * @param buf the netbuf to modify |
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217 | * @return -1 if there is no next part |
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218 | * 1 if moved to the next part but now there is no next part |
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219 | * 0 if moved to the next part and there are still more parts |
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220 | */ |
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221 | s8_t |
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222 | netbuf_next(struct netbuf *buf) |
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223 | { |
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224 | LWIP_ERROR("netbuf_next: invalid buf", (buf != NULL), return -1;); |
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225 | if (buf->ptr->next == NULL) { |
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226 | return -1; |
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227 | } |
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228 | buf->ptr = buf->ptr->next; |
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229 | if (buf->ptr->next == NULL) { |
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230 | return 1; |
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231 | } |
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232 | return 0; |
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233 | } |
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234 | |||
235 | /** |
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236 | * @ingroup netbuf |
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237 | * Move the current data pointer of a packet buffer contained in a netbuf |
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238 | * to the beginning of the packet. |
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239 | * The packet buffer itself is not modified. |
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240 | * |
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241 | * @param buf the netbuf to modify |
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242 | */ |
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243 | void |
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244 | netbuf_first(struct netbuf *buf) |
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245 | { |
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246 | LWIP_ERROR("netbuf_first: invalid buf", (buf != NULL), return;); |
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247 | buf->ptr = buf->p; |
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248 | } |
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249 | |||
250 | #endif /* LWIP_NETCONN */ |