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Example_RTOS
Rtos API example
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pbuf.h
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00001 /** 00002 * @file 00003 * pbuf API 00004 */ 00005 00006 /* 00007 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 00008 * All rights reserved. 00009 * 00010 * Redistribution and use in source and binary forms, with or without modification, 00011 * are permitted provided that the following conditions are met: 00012 * 00013 * 1. Redistributions of source code must retain the above copyright notice, 00014 * this list of conditions and the following disclaimer. 00015 * 2. Redistributions in binary form must reproduce the above copyright notice, 00016 * this list of conditions and the following disclaimer in the documentation 00017 * and/or other materials provided with the distribution. 00018 * 3. The name of the author may not be used to endorse or promote products 00019 * derived from this software without specific prior written permission. 00020 * 00021 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 00022 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00023 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 00024 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00025 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 00026 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00027 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00028 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 00029 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 00030 * OF SUCH DAMAGE. 00031 * 00032 * This file is part of the lwIP TCP/IP stack. 00033 * 00034 * Author: Adam Dunkels <adam@sics.se> 00035 * 00036 */ 00037 00038 #ifndef LWIP_HDR_PBUF_H 00039 #define LWIP_HDR_PBUF_H 00040 00041 #include "lwip/opt.h" 00042 #include "lwip/err.h" 00043 00044 #ifdef __cplusplus 00045 extern "C" { 00046 #endif 00047 00048 /** LWIP_SUPPORT_CUSTOM_PBUF==1: Custom pbufs behave much like their pbuf type 00049 * but they are allocated by external code (initialised by calling 00050 * pbuf_alloced_custom()) and when pbuf_free gives up their last reference, they 00051 * are freed by calling pbuf_custom->custom_free_function(). 00052 * Currently, the pbuf_custom code is only needed for one specific configuration 00053 * of IP_FRAG, unless required by external driver/application code. */ 00054 #ifndef LWIP_SUPPORT_CUSTOM_PBUF 00055 #define LWIP_SUPPORT_CUSTOM_PBUF ((IP_FRAG && !LWIP_NETIF_TX_SINGLE_PBUF) || (LWIP_IPV6 && LWIP_IPV6_FRAG)) 00056 #endif 00057 00058 /* @todo: We need a mechanism to prevent wasting memory in every pbuf 00059 (TCP vs. UDP, IPv4 vs. IPv6: UDP/IPv4 packets may waste up to 28 bytes) */ 00060 00061 #define PBUF_TRANSPORT_HLEN 20 00062 #if LWIP_IPV6 00063 #define PBUF_IP_HLEN 40 00064 #else 00065 #define PBUF_IP_HLEN 20 00066 #endif 00067 00068 /** 00069 * @ingroup pbuf 00070 * Enumeration of pbuf layers 00071 */ 00072 typedef enum { 00073 /** Includes spare room for transport layer header, e.g. UDP header. 00074 * Use this if you intend to pass the pbuf to functions like udp_send(). 00075 */ 00076 PBUF_TRANSPORT, 00077 /** Includes spare room for IP header. 00078 * Use this if you intend to pass the pbuf to functions like raw_send(). 00079 */ 00080 PBUF_IP, 00081 /** Includes spare room for link layer header (ethernet header). 00082 * Use this if you intend to pass the pbuf to functions like ethernet_output(). 00083 * @see PBUF_LINK_HLEN 00084 */ 00085 PBUF_LINK, 00086 /** Includes spare room for additional encapsulation header before ethernet 00087 * headers (e.g. 802.11). 00088 * Use this if you intend to pass the pbuf to functions like netif->linkoutput(). 00089 * @see PBUF_LINK_ENCAPSULATION_HLEN 00090 */ 00091 PBUF_RAW_TX, 00092 /** Use this for input packets in a netif driver when calling netif->input() 00093 * in the most common case - ethernet-layer netif driver. */ 00094 PBUF_RAW 00095 } pbuf_layer; 00096 00097 /** 00098 * @ingroup pbuf 00099 * Enumeration of pbuf types 00100 */ 00101 typedef enum { 00102 /** pbuf data is stored in RAM, used for TX mostly, struct pbuf and its payload 00103 are allocated in one piece of contiguous memory (so the first payload byte 00104 can be calculated from struct pbuf). 00105 pbuf_alloc() allocates PBUF_RAM pbufs as unchained pbufs (although that might 00106 change in future versions). 00107 This should be used for all OUTGOING packets (TX).*/ 00108 PBUF_RAM, 00109 /** pbuf data is stored in ROM, i.e. struct pbuf and its payload are located in 00110 totally different memory areas. Since it points to ROM, payload does not 00111 have to be copied when queued for transmission. */ 00112 PBUF_ROM, 00113 /** pbuf comes from the pbuf pool. Much like PBUF_ROM but payload might change 00114 so it has to be duplicated when queued before transmitting, depending on 00115 who has a 'ref' to it. */ 00116 PBUF_REF, 00117 /** pbuf payload refers to RAM. This one comes from a pool and should be used 00118 for RX. Payload can be chained (scatter-gather RX) but like PBUF_RAM, struct 00119 pbuf and its payload are allocated in one piece of contiguous memory (so 00120 the first payload byte can be calculated from struct pbuf). 00121 Don't use this for TX, if the pool becomes empty e.g. because of TCP queuing, 00122 you are unable to receive TCP acks! */ 00123 PBUF_POOL 00124 } pbuf_type; 00125 00126 00127 /** indicates this packet's data should be immediately passed to the application */ 00128 #define PBUF_FLAG_PUSH 0x01U 00129 /** indicates this is a custom pbuf: pbuf_free calls pbuf_custom->custom_free_function() 00130 when the last reference is released (plus custom PBUF_RAM cannot be trimmed) */ 00131 #define PBUF_FLAG_IS_CUSTOM 0x02U 00132 /** indicates this pbuf is UDP multicast to be looped back */ 00133 #define PBUF_FLAG_MCASTLOOP 0x04U 00134 /** indicates this pbuf was received as link-level broadcast */ 00135 #define PBUF_FLAG_LLBCAST 0x08U 00136 /** indicates this pbuf was received as link-level multicast */ 00137 #define PBUF_FLAG_LLMCAST 0x10U 00138 /** indicates this pbuf includes a TCP FIN flag */ 00139 #define PBUF_FLAG_TCP_FIN 0x20U 00140 00141 /** Main packet buffer struct */ 00142 struct pbuf { 00143 /** next pbuf in singly linked pbuf chain */ 00144 struct pbuf *next; 00145 00146 /** pointer to the actual data in the buffer */ 00147 void *payload; 00148 00149 /** 00150 * total length of this buffer and all next buffers in chain 00151 * belonging to the same packet. 00152 * 00153 * For non-queue packet chains this is the invariant: 00154 * p->tot_len == p->len + (p->next? p->next->tot_len: 0) 00155 */ 00156 u16_t tot_len; 00157 00158 /** length of this buffer */ 00159 u16_t len; 00160 00161 /** pbuf_type as u8_t instead of enum to save space */ 00162 u8_t /*pbuf_type*/ type; 00163 00164 /** misc flags */ 00165 u8_t flags; 00166 00167 /** 00168 * the reference count always equals the number of pointers 00169 * that refer to this pbuf. This can be pointers from an application, 00170 * the stack itself, or pbuf->next pointers from a chain. 00171 */ 00172 u16_t ref; 00173 }; 00174 00175 00176 /** Helper struct for const-correctness only. 00177 * The only meaning of this one is to provide a const payload pointer 00178 * for PBUF_ROM type. 00179 */ 00180 struct pbuf_rom { 00181 /** next pbuf in singly linked pbuf chain */ 00182 struct pbuf *next; 00183 00184 /** pointer to the actual data in the buffer */ 00185 const void *payload; 00186 }; 00187 00188 #if LWIP_SUPPORT_CUSTOM_PBUF 00189 /** Prototype for a function to free a custom pbuf */ 00190 typedef void (*pbuf_free_custom_fn)(struct pbuf *p); 00191 00192 /** A custom pbuf: like a pbuf, but following a function pointer to free it. */ 00193 struct pbuf_custom { 00194 /** The actual pbuf */ 00195 struct pbuf pbuf; 00196 /** This function is called when pbuf_free deallocates this pbuf(_custom) */ 00197 pbuf_free_custom_fn custom_free_function; 00198 }; 00199 #endif /* LWIP_SUPPORT_CUSTOM_PBUF */ 00200 00201 /** Define this to 0 to prevent freeing ooseq pbufs when the PBUF_POOL is empty */ 00202 #ifndef PBUF_POOL_FREE_OOSEQ 00203 #define PBUF_POOL_FREE_OOSEQ 1 00204 #endif /* PBUF_POOL_FREE_OOSEQ */ 00205 #if LWIP_TCP && TCP_QUEUE_OOSEQ && NO_SYS && PBUF_POOL_FREE_OOSEQ 00206 extern volatile u8_t pbuf_free_ooseq_pending; 00207 void pbuf_free_ooseq(void); 00208 /** When not using sys_check_timeouts(), call PBUF_CHECK_FREE_OOSEQ() 00209 at regular intervals from main level to check if ooseq pbufs need to be 00210 freed! */ 00211 #define PBUF_CHECK_FREE_OOSEQ() do { if(pbuf_free_ooseq_pending) { \ 00212 /* pbuf_alloc() reported PBUF_POOL to be empty -> try to free some \ 00213 ooseq queued pbufs now */ \ 00214 pbuf_free_ooseq(); }}while(0) 00215 #else /* LWIP_TCP && TCP_QUEUE_OOSEQ && NO_SYS && PBUF_POOL_FREE_OOSEQ */ 00216 /* Otherwise declare an empty PBUF_CHECK_FREE_OOSEQ */ 00217 #define PBUF_CHECK_FREE_OOSEQ() 00218 #endif /* LWIP_TCP && TCP_QUEUE_OOSEQ && NO_SYS && PBUF_POOL_FREE_OOSEQ*/ 00219 00220 /* Initializes the pbuf module. This call is empty for now, but may not be in future. */ 00221 #define pbuf_init() 00222 00223 struct pbuf *pbuf_alloc(pbuf_layer l, u16_t length, pbuf_type type); 00224 #if LWIP_SUPPORT_CUSTOM_PBUF 00225 struct pbuf *pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type, 00226 struct pbuf_custom *p, void *payload_mem, 00227 u16_t payload_mem_len); 00228 #endif /* LWIP_SUPPORT_CUSTOM_PBUF */ 00229 void pbuf_realloc(struct pbuf *p, u16_t size); 00230 u8_t pbuf_header(struct pbuf *p, s16_t header_size); 00231 u8_t pbuf_header_force(struct pbuf *p, s16_t header_size); 00232 void pbuf_ref(struct pbuf *p); 00233 u8_t pbuf_free(struct pbuf *p); 00234 u16_t pbuf_clen(const struct pbuf *p); 00235 void pbuf_cat(struct pbuf *head, struct pbuf *tail); 00236 void pbuf_chain(struct pbuf *head, struct pbuf *tail); 00237 struct pbuf *pbuf_dechain(struct pbuf *p); 00238 err_t pbuf_copy(struct pbuf *p_to, const struct pbuf *p_from); 00239 u16_t pbuf_copy_partial(const struct pbuf *p, void *dataptr, u16_t len, u16_t offset); 00240 err_t pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len); 00241 err_t pbuf_take_at(struct pbuf *buf, const void *dataptr, u16_t len, u16_t offset); 00242 struct pbuf *pbuf_skip(struct pbuf* in, u16_t in_offset, u16_t* out_offset); 00243 struct pbuf *pbuf_coalesce(struct pbuf *p, pbuf_layer layer); 00244 #if LWIP_CHECKSUM_ON_COPY 00245 err_t pbuf_fill_chksum(struct pbuf *p, u16_t start_offset, const void *dataptr, 00246 u16_t len, u16_t *chksum); 00247 #endif /* LWIP_CHECKSUM_ON_COPY */ 00248 #if LWIP_TCP && TCP_QUEUE_OOSEQ && LWIP_WND_SCALE 00249 void pbuf_split_64k(struct pbuf *p, struct pbuf **rest); 00250 #endif /* LWIP_TCP && TCP_QUEUE_OOSEQ && LWIP_WND_SCALE */ 00251 00252 u8_t pbuf_get_at(const struct pbuf* p, u16_t offset); 00253 int pbuf_try_get_at(const struct pbuf* p, u16_t offset); 00254 void pbuf_put_at(struct pbuf* p, u16_t offset, u8_t data); 00255 u16_t pbuf_memcmp(const struct pbuf* p, u16_t offset, const void* s2, u16_t n); 00256 u16_t pbuf_memfind(const struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset); 00257 u16_t pbuf_strstr(const struct pbuf* p, const char* substr); 00258 00259 #ifdef __cplusplus 00260 } 00261 #endif 00262 00263 #endif /* LWIP_HDR_PBUF_H */
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