/* * Copyright (c) 2001-2004 Swedish Institute of Computer Science. * All rights reserved.  *  * Redistribution and use in source and binary forms, with or without modification,  * are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, *    this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, *    this list of conditions and the following disclaimer in the documentation *    and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products *    derived from this software without specific prior written permission.  * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY  * OF SUCH DAMAGE. * * This file is part of the lwIP TCP/IP stack. *  * Author: Adam Dunkels <adam@sics.se> * */#ifndef __LWIP_UDP_H__#define __LWIP_UDP_H__#include "lwip/arch.h"#include "lwip/pbuf.h"#include "lwip/inet.h"#include "lwip/ip.h"#define UDP_HLEN 8struct udp_hdr {  PACK_STRUCT_FIELD(u16_t src);  PACK_STRUCT_FIELD(u16_t dest);  /* src/dest UDP ports */  PACK_STRUCT_FIELD(u16_t len);  PACK_STRUCT_FIELD(u16_t chksum);} PACK_STRUCT_STRUCT;#define UDP_FLAGS_NOCHKSUM 0x01U#define UDP_FLAGS_UDPLITE  0x02U#define UDP_FLAGS_CONNECTED  0x04Ustruct udp_pcb {/* Common members of all PCB types */  IP_PCB;/* Protocol specific PCB members */  struct udp_pcb *next;  u8_t flags;  u16_t local_port, remote_port;    u16_t chksum_len;    void (* recv)(void *arg, struct udp_pcb *pcb, struct pbuf *p,    struct ip_addr *addr, u16_t port);  void *recv_arg;  };/* udp_pcbs export for exernal reference (e.g. SNMP agent) */extern struct udp_pcb *udp_pcbs;/* The following functions is the application layer interface to the   UDP code. */struct udp_pcb * udp_new        (void);void             udp_remove     (struct udp_pcb *pcb);err_t            udp_bind       (struct udp_pcb *pcb, struct ip_addr *ipaddr,                 u16_t port);err_t            udp_connect    (struct udp_pcb *pcb, struct ip_addr *ipaddr,                 u16_t port);void             udp_disconnect    (struct udp_pcb *pcb);void             udp_recv       (struct udp_pcb *pcb,         void (* recv)(void *arg, struct udp_pcb *upcb,                 struct pbuf *p,                 struct ip_addr *addr,                 u16_t port),         void *recv_arg);err_t            udp_sendto     (struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *dst_ip, u16_t dst_port);err_t            udp_send       (struct udp_pcb *pcb, struct pbuf *p);#define          udp_flags(pcb)  ((pcb)->flags)#define          udp_setflags(pcb, f)  ((pcb)->flags = (f))/* The following functions are the lower layer interface to UDP. */void             udp_input      (struct pbuf *p, struct netif *inp);void             udp_init       (void);#if UDP_DEBUGvoid udp_debug_print(struct udp_hdr *udphdr);#else#define udp_debug_print(udphdr)#endif#endif /* __LWIP_UDP_H__ */