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      1 /*
      2  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without modification,
      6  * are permitted provided that the following conditions are met:
      7  *
      8  * 1. Redistributions of source code must retain the above copyright notice,
      9  *    this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright notice,
     11  *    this list of conditions and the following disclaimer in the documentation
     12  *    and/or other materials provided with the distribution.
     13  * 3. The name of the author may not be used to endorse or promote products
     14  *    derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
     19  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
     21  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
     24  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
     25  * OF SUCH DAMAGE.
     26  *
     27  * This file is part of the lwIP TCP/IP stack.
     28  *
     29  * Author: Adam Dunkels <adam (at) sics.se>
     30  *
     31  */
     32 #ifndef __LWIP_UDP_H__
     33 #define __LWIP_UDP_H__
     34 
     35 #include "lwip/opt.h"
     36 
     37 #if LWIP_UDP /* don't build if not configured for use in lwipopts.h */
     38 
     39 #include "lwip/pbuf.h"
     40 #include "lwip/netif.h"
     41 #include "lwip/ip_addr.h"
     42 #include "lwip/ip.h"
     43 
     44 #ifdef __cplusplus
     45 extern "C" {
     46 #endif
     47 
     48 #define UDP_HLEN 8
     49 
     50 /* Fields are (of course) in network byte order. */
     51 #ifdef PACK_STRUCT_USE_INCLUDES
     52 #  include "arch/bpstruct.h"
     53 #endif
     54 PACK_STRUCT_BEGIN
     55 struct udp_hdr {
     56   PACK_STRUCT_FIELD(u16_t src);
     57   PACK_STRUCT_FIELD(u16_t dest);  /* src/dest UDP ports */
     58   PACK_STRUCT_FIELD(u16_t len);
     59   PACK_STRUCT_FIELD(u16_t chksum);
     60 } PACK_STRUCT_STRUCT;
     61 PACK_STRUCT_END
     62 #ifdef PACK_STRUCT_USE_INCLUDES
     63 #  include "arch/epstruct.h"
     64 #endif
     65 
     66 #define UDP_FLAGS_NOCHKSUM       0x01U
     67 #define UDP_FLAGS_UDPLITE        0x02U
     68 #define UDP_FLAGS_CONNECTED      0x04U
     69 #define UDP_FLAGS_MULTICAST_LOOP 0x08U
     70 
     71 struct udp_pcb;
     72 
     73 /** Function prototype for udp pcb receive callback functions
     74  * addr and port are in same byte order as in the pcb
     75  * The callback is responsible for freeing the pbuf
     76  * if it's not used any more.
     77  *
     78  * ATTENTION: Be aware that 'addr' points into the pbuf 'p' so freeing this pbuf
     79  *            makes 'addr' invalid, too.
     80  *
     81  * @param arg user supplied argument (udp_pcb.recv_arg)
     82  * @param pcb the udp_pcb which received data
     83  * @param p the packet buffer that was received
     84  * @param addr the remote IP address from which the packet was received
     85  * @param port the remote port from which the packet was received
     86  */
     87 typedef void (*udp_recv_fn)(void *arg, struct udp_pcb *pcb, struct pbuf *p,
     88     ip_addr_t *addr, u16_t port);
     89 
     90 
     91 struct udp_pcb {
     92 /* Common members of all PCB types */
     93   IP_PCB;
     94 
     95 /* Protocol specific PCB members */
     96 
     97   struct udp_pcb *next;
     98 
     99   u8_t flags;
    100   /** ports are in host byte order */
    101   u16_t local_port, remote_port;
    102 
    103 #if LWIP_IGMP
    104   /** outgoing network interface for multicast packets */
    105   ip_addr_t multicast_ip;
    106 #endif /* LWIP_IGMP */
    107 
    108 #if LWIP_UDPLITE
    109   /** used for UDP_LITE only */
    110   u16_t chksum_len_rx, chksum_len_tx;
    111 #endif /* LWIP_UDPLITE */
    112 
    113   /** receive callback function */
    114   udp_recv_fn recv;
    115   /** user-supplied argument for the recv callback */
    116   void *recv_arg;
    117 };
    118 /* udp_pcbs export for exernal reference (e.g. SNMP agent) */
    119 extern struct udp_pcb *udp_pcbs;
    120 
    121 /* The following functions is the application layer interface to the
    122    UDP code. */
    123 struct udp_pcb * udp_new        (void);
    124 void             udp_remove     (struct udp_pcb *pcb);
    125 err_t            udp_bind       (struct udp_pcb *pcb, ip_addr_t *ipaddr,
    126                                  u16_t port);
    127 err_t            udp_connect    (struct udp_pcb *pcb, ip_addr_t *ipaddr,
    128                                  u16_t port);
    129 void             udp_disconnect (struct udp_pcb *pcb);
    130 void             udp_recv       (struct udp_pcb *pcb, udp_recv_fn recv,
    131                                  void *recv_arg);
    132 err_t            udp_sendto_if  (struct udp_pcb *pcb, struct pbuf *p,
    133                                  ip_addr_t *dst_ip, u16_t dst_port,
    134                                  struct netif *netif);
    135 err_t            udp_sendto     (struct udp_pcb *pcb, struct pbuf *p,
    136                                  ip_addr_t *dst_ip, u16_t dst_port);
    137 err_t            udp_send       (struct udp_pcb *pcb, struct pbuf *p);
    138 
    139 #if LWIP_CHECKSUM_ON_COPY
    140 err_t            udp_sendto_if_chksum(struct udp_pcb *pcb, struct pbuf *p,
    141                                  ip_addr_t *dst_ip, u16_t dst_port,
    142                                  struct netif *netif, u8_t have_chksum,
    143                                  u16_t chksum);
    144 err_t            udp_sendto_chksum(struct udp_pcb *pcb, struct pbuf *p,
    145                                  ip_addr_t *dst_ip, u16_t dst_port,
    146                                  u8_t have_chksum, u16_t chksum);
    147 err_t            udp_send_chksum(struct udp_pcb *pcb, struct pbuf *p,
    148                                  u8_t have_chksum, u16_t chksum);
    149 #endif /* LWIP_CHECKSUM_ON_COPY */
    150 
    151 #define          udp_flags(pcb) ((pcb)->flags)
    152 #define          udp_setflags(pcb, f)  ((pcb)->flags = (f))
    153 
    154 /* The following functions are the lower layer interface to UDP. */
    155 void             udp_input      (struct pbuf *p, struct netif *inp);
    156 
    157 #define udp_init() /* Compatibility define, not init needed. */
    158 
    159 #if UDP_DEBUG
    160 void udp_debug_print(struct udp_hdr *udphdr);
    161 #else
    162 #define udp_debug_print(udphdr)
    163 #endif
    164 
    165 #ifdef __cplusplus
    166 }
    167 #endif
    168 
    169 #endif /* LWIP_UDP */
    170 
    171 #endif /* __LWIP_UDP_H__ */
    172