udp.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 #ifndef __LWIP_UDP_H__
00033 #define __LWIP_UDP_H__
00034 
00035 #include "lwip/opt.h"
00036 
00037 #if LWIP_UDP /* don't build if not configured for use in lwipopts.h */
00038 
00039 #include "lwip/pbuf.h"
00040 #include "lwip/netif.h"
00041 #include "lwip/ip_addr.h"
00042 #include "lwip/ip.h"
00043 
00044 #ifdef __cplusplus
00045 extern "C" {
00046 #endif
00047 
00048 #define UDP_HLEN 8
00049 
00050 /* Fields are (of course) in network byte order. */
00051 #ifdef PACK_STRUCT_USE_INCLUDES
00052 #  include "arch/bpstruct.h"
00053 #endif
00054 PACK_STRUCT_BEGIN
00055 struct udp_hdr {
00056   PACK_STRUCT_FIELD(u16_t src);
00057   PACK_STRUCT_FIELD(u16_t dest);  /* src/dest UDP ports */
00058   PACK_STRUCT_FIELD(u16_t len);
00059   PACK_STRUCT_FIELD(u16_t chksum);
00060 } PACK_STRUCT_STRUCT;
00061 PACK_STRUCT_END
00062 #ifdef PACK_STRUCT_USE_INCLUDES
00063 #  include "arch/epstruct.h"
00064 #endif
00065 
00066 #define UDP_FLAGS_NOCHKSUM 0x01U
00067 #define UDP_FLAGS_UDPLITE  0x02U
00068 #define UDP_FLAGS_CONNECTED  0x04U
00069 
00070 struct udp_pcb;
00071 
00072 /** Function prototype for udp pcb receive callback functions
00073  * addr and port are in same byte order as in the pcb
00074  * The callback is responsible for freeing the pbuf
00075  * if it's not used any more.
00076  *
00077  * ATTENTION: Be aware that 'addr' points into the pbuf 'p' so freeing this pbuf
00078  *            makes 'addr' invalid, too.
00079  *
00080  * @param arg user supplied argument (udp_pcb.recv_arg)
00081  * @param pcb the udp_pcb which received data
00082  * @param p the packet buffer that was received
00083  * @param addr the remote IP address from which the packet was received
00084  * @param port the remote port from which the packet was received
00085  */
00086 typedef void (*udp_recv_fn)(void *arg, struct udp_pcb *pcb, struct pbuf *p,
00087     ip_addr_t *addr, u16_t port);
00088 
00089 
00090 struct udp_pcb {
00091 /* Common members of all PCB types */
00092   IP_PCB;
00093 
00094 /* Protocol specific PCB members */
00095 
00096   struct udp_pcb *next;
00097 
00098   u8_t flags;
00099   /** ports are in host byte order */
00100   u16_t local_port, remote_port;
00101 
00102 #if LWIP_IGMP
00103   /** outgoing network interface for multicast packets */
00104   ip_addr_t multicast_ip;
00105 #endif /* LWIP_IGMP */
00106 
00107 #if LWIP_UDPLITE
00108   /** used for UDP_LITE only */
00109   u16_t chksum_len_rx, chksum_len_tx;
00110 #endif /* LWIP_UDPLITE */
00111 
00112   /** receive callback function */
00113   udp_recv_fn recv;
00114   /** user-supplied argument for the recv callback */
00115   void *recv_arg;  
00116 };
00117 /* udp_pcbs export for exernal reference (e.g. SNMP agent) */
00118 extern struct udp_pcb *udp_pcbs;
00119 
00120 /* The following functions is the application layer interface to the
00121    UDP code. */
00122 struct udp_pcb * udp_new        (void);
00123 void             udp_remove     (struct udp_pcb *pcb);
00124 err_t            udp_bind       (struct udp_pcb *pcb, ip_addr_t *ipaddr,
00125                                  u16_t port);
00126 err_t            udp_connect    (struct udp_pcb *pcb, ip_addr_t *ipaddr,
00127                                  u16_t port);
00128 void             udp_disconnect (struct udp_pcb *pcb);
00129 void             udp_recv       (struct udp_pcb *pcb, udp_recv_fn recv,
00130                                  void *recv_arg);
00131 err_t            udp_sendto_if  (struct udp_pcb *pcb, struct pbuf *p,
00132                                  ip_addr_t *dst_ip, u16_t dst_port,
00133                                  struct netif *netif);
00134 err_t            udp_sendto     (struct udp_pcb *pcb, struct pbuf *p,
00135                                  ip_addr_t *dst_ip, u16_t dst_port);
00136 err_t            udp_send       (struct udp_pcb *pcb, struct pbuf *p);
00137 
00138 #define          udp_flags(pcb) ((pcb)->flags)
00139 #define          udp_setflags(pcb, f)  ((pcb)->flags = (f))
00140 
00141 /* The following functions are the lower layer interface to UDP. */
00142 void             udp_input      (struct pbuf *p, struct netif *inp);
00143 
00144 #define udp_init() /* Compatibility define, not init needed. */
00145 
00146 #if UDP_DEBUG
00147 void udp_debug_print(struct udp_hdr *udphdr);
00148 #else
00149 #define udp_debug_print(udphdr)
00150 #endif
00151 
00152 #ifdef __cplusplus
00153 }
00154 #endif
00155 
00156 #endif /* LWIP_UDP */
00157 
00158 #endif /* __LWIP_UDP_H__ */