sys/lib/libsa/udp.c

   1 /*      $NetBSD: udp.c,v 1.11 2011/05/11 16:23:40 zoltan Exp $  */
   2
   3 /*
   4  * Copyright (c) 1992 Regents of the University of California.
   5  * All rights reserved.
   6  *
   7  * This software was developed by the Computer Systems Engineering group
   8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
   9  * contributed to Berkeley.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgement:
  21  *      This product includes software developed by the University of
  22  *      California, Lawrence Berkeley Laboratory and its contributors.
  23  * 4. Neither the name of the University nor the names of its contributors
  24  *    may be used to endorse or promote products derived from this software
  25  *    without specific prior written permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  37  * SUCH DAMAGE.
  38  *
  39  * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp  (LBL)
  40  */
  41
  42 #include <sys/param.h>
  43 #include <sys/socket.h>
  44
  45 #ifdef _STANDALONE
  46 #include <lib/libkern/libkern.h>
  47 #else
  48 #include <string.h>
  49 #endif
  50
  51 #include <net/if.h>
  52 #include <net/if_ether.h>
  53
  54 #include <netinet/in.h>
  55 #include <netinet/in_systm.h>
  56 #include <netinet/ip.h>
  57 #include <netinet/ip_var.h>
  58 #include <netinet/udp.h>
  59 #include <netinet/udp_var.h>
  60
  61 #include "stand.h"
  62 #include "net.h"
  63
  64
  65 /* Caller must leave room for ethernet, ip and udp headers in front!! */
  66 ssize_t
  67 sendudp(struct iodesc *d, void *pkt, size_t len)
  68 {
  69         ssize_t cc;
  70         struct udphdr *uh;
  71
  72 #ifdef NET_DEBUG
  73         if (debug) {
  74                 printf("sendudp: d=%lx called.\n", (long)d);
  75                 if (d) {
  76                         printf("saddr: %s:%d",
  77                             inet_ntoa(d->myip), ntohs(d->myport));
  78                         printf(" daddr: %s:%d\n",
  79                             inet_ntoa(d->destip), ntohs(d->destport));
  80                 }
  81         }
  82 #endif
  83
  84         uh = (struct udphdr *)pkt - 1;
  85         len += sizeof(*uh);
  86
  87         (void)memset(uh, 0, sizeof(*uh));
  88
  89         uh->uh_sport = d->myport;
  90         uh->uh_dport = d->destport;
  91         uh->uh_ulen = htons(len);
  92
  93         cc = sendip(d, uh, len, IPPROTO_UDP);
  94         if (cc == -1)
  95                 return -1;
  96         if ((size_t)cc != len)
  97                 panic("sendudp: bad write (%zd != %zu)", cc, len);
  98         return (cc - sizeof(*uh));
  99 }
 100
 101 /*
 102  * Receive a UDP packet and validate it is for us.
 103  * Caller leaves room for the headers (Ether, IP, UDP)
 104  */
 105 ssize_t
 106 readudp(struct iodesc *d, void *pkt, size_t len, saseconds_t tleft)
 107 {
 108         ssize_t n;
 109         struct udphdr *uh;
 110
 111         uh = (struct udphdr *)pkt - 1;
 112         n = readip(d, uh, len + sizeof(*uh), tleft, IPPROTO_UDP);
 113         if (n == -1 || (size_t)n < sizeof(*uh))
 114                 return -1;
 115
 116         if (uh->uh_dport != d->myport) {
 117 #ifdef NET_DEBUG
 118                 if (debug)
 119                         printf("readudp: bad dport %d != %d\n",
 120                                 d->myport, ntohs(uh->uh_dport));
 121 #endif
 122                 return -1;
 123         }
 124
 125         if (ntohs(uh->uh_ulen) < sizeof(*uh)) {
 126 #ifdef NET_DEBUG
 127                 if (debug)
 128                         printf("readudp: bad udp len %d < %d\n",
 129                                 ntohs(uh->uh_ulen), (int)sizeof(*uh));
 130 #endif
 131                 return -1;
 132         }
 133
 134         n -= sizeof(*uh);
 135         return n;
 136 }