qemu/roms/SLOF/clients/net-snk/app/netlib/udp.c

   1 /******************************************************************************
   2  * Copyright (c) 2004, 2008 IBM Corporation
   3  * All rights reserved.
   4  * This program and the accompanying materials
   5  * are made available under the terms of the BSD License
   6  * which accompanies this distribution, and is available at
   7  * http://www.opensource.org/licenses/bsd-license.php
   8  *
   9  * Contributors:
  10  *     IBM Corporation - initial implementation
  11  *****************************************************************************/
  12
  13 /************************ DEFINITIONS & DECLARATIONS *********************/
  14
  15 #include <udp.h>
  16 #include <sys/socket.h>
  17 #include <dhcp.h>
  18 #include <dhcpv6.h>
  19 #include <dns.h>
  20 #ifdef USE_MTFTP
  21 #include <mtftp.h>
  22 #else
  23 #include <tftp.h>
  24 #endif
  25
  26
  27
  28 /****************************** LOCAL VARIABLES **************************/
  29
  30
  31 #ifdef USE_MTFTP
  32
  33 uint16_t net_tftp_uport;
  34 uint16_t net_mtftp_uport;
  35
  36 void net_set_tftp_port(uint16_t tftp_port)
  37 {
  38         net_tftp_uport = tftp_port;
  39 }
  40
  41 void net_set_mtftp_port(uint16_t tftp_port)
  42 {
  43         net_mtftp_uport = tftp_port;
  44 }
  45
  46 #endif
  47
  48 /****************************** IMPLEMENTATION ***************************/
  49
  50
  51 /**
  52  * NET: Handles UDP-packets according to Receive-handle diagram.
  53  *
  54  * @param  udp_packet UDP-packet to be handled
  55  * @param  packetsize Length of the packet
  56  * @return            ZERO - packet handled successfully;
  57  *                    NON ZERO - packet was not handled (e.g. bad format)
  58  * @see               receive_ether
  59  * @see               udphdr
  60  */
  61 int8_t handle_udp(int fd, uint8_t * udp_packet, uint32_t packetsize)
  62 {
  63         struct udphdr * udph = (struct udphdr *) udp_packet;
  64
  65         if (packetsize < sizeof(struct udphdr))
  66                 return -1; // packet is too small
  67
  68         switch (htons(udph -> uh_dport)) {
  69         case UDPPORT_BOOTPC:
  70                 if (udph -> uh_sport == htons(UDPPORT_BOOTPS))
  71                         return handle_dhcp(fd, udp_packet + sizeof(struct udphdr),
  72                                             packetsize - sizeof(struct udphdr));
  73                 else
  74                         return -1;
  75         case UDPPORT_DNSC:
  76                 if (udph -> uh_sport == htons(UDPPORT_DNSS))
  77                         return handle_dns(udp_packet + sizeof(struct udphdr),
  78                                           packetsize - sizeof(struct udphdr));
  79                 else
  80                         return -1;
  81         case UDPPORT_DHCPV6C:
  82                 return handle_dhcpv6(udp_packet+sizeof(struct udphdr),
  83                                      packetsize - sizeof(struct udphdr));
  84         case UDPPORT_TFTPC:
  85 #ifdef USE_MTFTP
  86                 return handle_tftp(fd, udp_packet + sizeof(struct udphdr),
  87                                        packetsize - sizeof(struct udphdr));
  88 #else
  89                 return handle_tftp(fd, udp_packet, packetsize);
  90 #endif
  91         default:
  92 #ifdef USE_MTFTP
  93                 if (htons(udph -> uh_dport) == net_tftp_uport)
  94                         return handle_tftp(fd, udp_packet + sizeof(struct udphdr),
  95                        packetsize - sizeof(struct udphdr));
  96                 else if (htons(udph -> uh_dport) == net_mtftp_uport)
  97                         return handle_tftp(fd, udp_packet + sizeof(struct udphdr),
  98                        packetsize - sizeof(struct udphdr));
  99 #endif
 100                 return -1;
 101         }
 102 }
 103
 104 /**
 105  * NET: This function handles situation when "Destination unreachable"
 106  *      ICMP-error occurs during sending UDP-packet.
 107  *
 108  * @param  err_code   Error Code (e.g. "Host unreachable")
 109  * @param  packet     original UDP-packet
 110  * @param  packetsize length of the packet
 111  * @see               handle_icmp
 112  */
 113 void handle_udp_dun(uint8_t * udp_packet, uint32_t packetsize, uint8_t err_code)
 114 {
 115         struct udphdr * udph = (struct udphdr *) udp_packet;
 116
 117         if (packetsize < sizeof(struct udphdr))
 118                 return; // packet is too small
 119
 120         switch (htons(udph -> uh_sport)) {
 121         case UDPPORT_TFTPC:
 122                 handle_tftp_dun(err_code);
 123                 break;
 124         }
 125 }
 126
 127 /**
 128  * NET: Creates UDP-packet. Places UDP-header in a packet and fills it
 129  *      with corresponding information.
 130  *      <p>
 131  *      Use this function with similar functions for other network layers
 132  *      (fill_ethhdr, fill_iphdr, fill_dnshdr, fill_btphdr).
 133  *
 134  * @param  packet      Points to the place where UDP-header must be placed.
 135  * @param  packetsize  Size of the packet in bytes incl. this hdr and data.
 136  * @param  src_port    UDP source port
 137  * @param  dest_port   UDP destination port
 138  * @see                udphdr
 139  * @see                fill_ethhdr
 140  * @see                fill_iphdr
 141  * @see                fill_dnshdr
 142  * @see                fill_btphdr
 143  */
 144 void fill_udphdr(uint8_t * packet, uint16_t packetsize,
 145                  uint16_t src_port, uint16_t dest_port)
 146 {
 147         struct udphdr * udph = (struct udphdr *) packet;
 148
 149         udph -> uh_sport = htons(src_port);
 150         udph -> uh_dport = htons(dest_port);
 151         udph -> uh_ulen = htons(packetsize);
 152         udph -> uh_sum = htons(0);
 153 }