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 #define UDP_FLAGS_MULTICAST_LOOP 0x08U
00070 
00071 struct udp_pcb;
00072 
00073 /** Function prototype for udp pcb receive callback functions
00074  * addr and port are in same byte order as in the pcb
00075  * The callback is responsible for freeing the pbuf
00076  * if it's not used any more.
00077  *
00078  * ATTENTION: Be aware that 'addr' points into the pbuf 'p' so freeing this pbuf
00079  *            makes 'addr' invalid, too.
00080  *
00081  * @param arg user supplied argument (udp_pcb.recv_arg)
00082  * @param pcb the udp_pcb which received data
00083  * @param p the packet buffer that was received
00084  * @param addr the remote IP address from which the packet was received
00085  * @param port the remote port from which the packet was received
00086  */
00087 typedef void (*udp_recv_fn)(void *arg, struct udp_pcb *pcb, struct pbuf *p,
00088     ip_addr_t *addr, u16_t port);
00089 
00090 
00091 struct udp_pcb {
00092 /* Common members of all PCB types */
00093   IP_PCB;
00094 
00095 /* Protocol specific PCB members */
00096 
00097   struct udp_pcb *next;
00098 
00099   u8_t flags;
00100   /** ports are in host byte order */
00101   u16_t local_port, remote_port;
00102 
00103 #if LWIP_IGMP
00104   /** outgoing network interface for multicast packets */
00105   ip_addr_t multicast_ip;
00106 #endif /* LWIP_IGMP */
00107 
00108 #if LWIP_UDPLITE
00109   /** used for UDP_LITE only */
00110   u16_t chksum_len_rx, chksum_len_tx;
00111 #endif /* LWIP_UDPLITE */
00112 
00113   /** receive callback function */
00114   udp_recv_fn recv;
00115   /** user-supplied argument for the recv callback */
00116   void *recv_arg;  
00117 };
00118 /* udp_pcbs export for exernal reference (e.g. SNMP agent) */
00119 extern struct udp_pcb *udp_pcbs;
00120 
00121 /* The following functions is the application layer interface to the
00122    UDP code. */
00123 struct udp_pcb * udp_new        (void);
00124 void             udp_remove     (struct udp_pcb *pcb);
00125 err_t            udp_bind       (struct udp_pcb *pcb, ip_addr_t *ipaddr,
00126                                  u16_t port);
00127 err_t            udp_connect    (struct udp_pcb *pcb, ip_addr_t *ipaddr,
00128                                  u16_t port);
00129 void             udp_disconnect (struct udp_pcb *pcb);
00130 void             udp_recv       (struct udp_pcb *pcb, udp_recv_fn recv,
00131                                  void *recv_arg);
00132 err_t            udp_sendto_if  (struct udp_pcb *pcb, struct pbuf *p,
00133                                  ip_addr_t *dst_ip, u16_t dst_port,
00134                                  struct netif *netif);
00135 err_t            udp_sendto     (struct udp_pcb *pcb, struct pbuf *p,
00136                                  ip_addr_t *dst_ip, u16_t dst_port);
00137 err_t            udp_send       (struct udp_pcb *pcb, struct pbuf *p);
00138 
00139 #if LWIP_CHECKSUM_ON_COPY
00140 err_t            udp_sendto_if_chksum(struct udp_pcb *pcb, struct pbuf *p,
00141                                  ip_addr_t *dst_ip, u16_t dst_port,
00142                                  struct netif *netif, u8_t have_chksum,
00143                                  u16_t chksum);
00144 err_t            udp_sendto_chksum(struct udp_pcb *pcb, struct pbuf *p,
00145                                  ip_addr_t *dst_ip, u16_t dst_port,
00146                                  u8_t have_chksum, u16_t chksum);
00147 err_t            udp_send_chksum(struct udp_pcb *pcb, struct pbuf *p,
00148                                  u8_t have_chksum, u16_t chksum);
00149 #endif /* LWIP_CHECKSUM_ON_COPY */
00150 
00151 #define          udp_flags(pcb) ((pcb)->flags)
00152 #define          udp_setflags(pcb, f)  ((pcb)->flags = (f))
00153 
00154 /* The following functions are the lower layer interface to UDP. */
00155 void             udp_input      (struct pbuf *p, struct netif *inp);
00156 
00157 #define udp_init() /* Compatibility define, not init needed. */
00158 
00159 #if UDP_DEBUG
00160 void udp_debug_print(struct udp_hdr *udphdr);
00161 #else
00162 #define udp_debug_print(udphdr)
00163 #endif
00164 
00165 #ifdef __cplusplus
00166 }
00167 #endif
00168 
00169 #endif /* LWIP_UDP */
00170 
00171 #endif /* __LWIP_UDP_H__ */