Some quick code to use UDP-only (no TCP) with mBed. Echos received packets and sends packets when a button is pressed
pbuf.h
00001 /* 00002 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 00003 * All rights reserved. 00004 * 00005 * Redistribution and use in source and binary forms, with or without modification, 00006 * are permitted provided that the following conditions are met: 00007 * 00008 * 1. Redistributions of source code must retain the above copyright notice, 00009 * this list of conditions and the following disclaimer. 00010 * 2. Redistributions in binary form must reproduce the above copyright notice, 00011 * this list of conditions and the following disclaimer in the documentation 00012 * and/or other materials provided with the distribution. 00013 * 3. The name of the author may not be used to endorse or promote products 00014 * derived from this software without specific prior written permission. 00015 * 00016 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 00017 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00018 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 00019 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00020 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 00021 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00022 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00023 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 00024 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 00025 * OF SUCH DAMAGE. 00026 * 00027 * This file is part of the lwIP TCP/IP stack. 00028 * 00029 * Author: Adam Dunkels <adam@sics.se> 00030 * 00031 */ 00032 00033 #ifndef __LWIP_PBUF_H__ 00034 #define __LWIP_PBUF_H__ 00035 00036 #include "lwip/opt.h" 00037 #include "lwip/err.h" 00038 00039 #ifdef __cplusplus 00040 extern "C" { 00041 #endif 00042 00043 #define PBUF_TRANSPORT_HLEN 20 00044 #define PBUF_IP_HLEN 20 00045 00046 typedef enum { 00047 PBUF_TRANSPORT, 00048 PBUF_IP, 00049 PBUF_LINK, 00050 PBUF_RAW 00051 } pbuf_layer; 00052 00053 typedef enum { 00054 PBUF_RAM, /* pbuf data is stored in RAM */ 00055 PBUF_ROM, /* pbuf data is stored in ROM */ 00056 PBUF_REF, /* pbuf comes from the pbuf pool */ 00057 PBUF_POOL /* pbuf payload refers to RAM */ 00058 } pbuf_type; 00059 00060 00061 /** indicates this packet's data should be immediately passed to the application */ 00062 #define PBUF_FLAG_PUSH 0x01U 00063 00064 struct pbuf { 00065 /** next pbuf in singly linked pbuf chain */ 00066 struct pbuf *next; 00067 00068 /** pointer to the actual data in the buffer */ 00069 void *payload; 00070 00071 /** 00072 * total length of this buffer and all next buffers in chain 00073 * belonging to the same packet. 00074 * 00075 * For non-queue packet chains this is the invariant: 00076 * p->tot_len == p->len + (p->next? p->next->tot_len: 0) 00077 */ 00078 u16_t tot_len; 00079 00080 /** length of this buffer */ 00081 u16_t len; 00082 00083 /** pbuf_type as u8_t instead of enum to save space */ 00084 u8_t /*pbuf_type*/ type; 00085 00086 /** misc flags */ 00087 u8_t flags; 00088 00089 /** 00090 * the reference count always equals the number of pointers 00091 * that refer to this pbuf. This can be pointers from an application, 00092 * the stack itself, or pbuf->next pointers from a chain. 00093 */ 00094 u16_t ref; 00095 00096 }; 00097 00098 /* Initializes the pbuf module. This call is empty for now, but may not be in future. */ 00099 #define pbuf_init() 00100 00101 struct pbuf *pbuf_alloc(pbuf_layer l, u16_t size, pbuf_type type); 00102 void pbuf_realloc(struct pbuf *p, u16_t size); 00103 u8_t pbuf_header(struct pbuf *p, s16_t header_size); 00104 void pbuf_ref(struct pbuf *p); 00105 void pbuf_ref_chain(struct pbuf *p); 00106 u8_t pbuf_free(struct pbuf *p); 00107 u8_t pbuf_clen(struct pbuf *p); 00108 void pbuf_cat(struct pbuf *head, struct pbuf *tail); 00109 void pbuf_chain(struct pbuf *head, struct pbuf *tail); 00110 struct pbuf *pbuf_dechain(struct pbuf *p); 00111 err_t pbuf_copy(struct pbuf *p_to, struct pbuf *p_from); 00112 u16_t pbuf_copy_partial(struct pbuf *p, void *dataptr, u16_t len, u16_t offset); 00113 err_t pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len); 00114 struct pbuf *pbuf_coalesce(struct pbuf *p, pbuf_layer layer); 00115 00116 #ifdef __cplusplus 00117 } 00118 #endif 00119 00120 #endif /* __LWIP_PBUF_H__ */
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