usr/src/boot/lib/libstand/udp.c

   1 /* Taken from $NetBSD: net.c,v 1.20 1997/12/26 22:41:30 scottr 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  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp  (LBL)
  36  */
  37
  38 #include <sys/cdefs.h>
  39
  40 #include <sys/param.h>
  41 #include <sys/socket.h>
  42
  43 #include <string.h>
  44
  45 #include <net/if.h>
  46 #include <netinet/in.h>
  47 #include <netinet/if_ether.h>
  48 #include <netinet/in_systm.h>
  49
  50 #include <netinet/in_pcb.h>
  51 #include <netinet/ip.h>
  52 #include <netinet/ip_var.h>
  53 #include <netinet/udp.h>
  54 #include <netinet/udp_var.h>
  55
  56 #include "stand.h"
  57 #include "net.h"
  58
  59 /* Caller must leave room for ethernet, ip and udp headers in front!! */
  60 ssize_t
  61 sendudp(struct iodesc *d, void *pkt, size_t len)
  62 {
  63         ssize_t cc;
  64         struct udpiphdr *ui;
  65         struct udphdr *uh;
  66
  67 #ifdef NET_DEBUG
  68         if (debug) {
  69                 printf("sendudp: d=%lx called.\n", (long)d);
  70                 if (d) {
  71                         printf("saddr: %s:%d",
  72                             inet_ntoa(d->myip), ntohs(d->myport));
  73                         printf(" daddr: %s:%d\n",
  74                             inet_ntoa(d->destip), ntohs(d->destport));
  75                 }
  76         }
  77 #endif
  78
  79         ui = (struct udpiphdr *)pkt - 1;
  80         bzero(ui, sizeof(*ui));
  81
  82         uh = (struct udphdr *)pkt - 1;
  83         len += sizeof(*uh);
  84
  85         uh->uh_sport = d->myport;
  86         uh->uh_dport = d->destport;
  87         uh->uh_ulen = htons(len);
  88
  89         ui->ui_pr = IPPROTO_UDP;
  90         ui->ui_len = uh->uh_ulen;
  91         ui->ui_src = d->myip;
  92         ui->ui_dst = d->destip;
  93
  94 #ifndef UDP_NO_CKSUM
  95         uh->uh_sum = in_cksum(ui, len + sizeof (struct ip));
  96 #endif
  97
  98         cc = sendip(d, uh, len, IPPROTO_UDP);
  99         if (cc == -1)
 100                 return (-1);
 101         if (cc != len)
 102                 panic("sendudp: bad write (%zd != %zd)", cc, len);
 103         return (cc - sizeof(*uh));
 104 }
 105
 106 /*
 107  * Receive a UDP packet and validate it is for us.
 108  */
 109 ssize_t
 110 readudp(struct iodesc *d, void **pkt, void **payload, time_t tleft)
 111 {
 112         ssize_t n;
 113         struct udphdr *uh;
 114         void *ptr;
 115
 116 #ifdef NET_DEBUG
 117         if (debug)
 118                 printf("readudp: called\n");
 119 #endif
 120
 121         uh = NULL;
 122         ptr = NULL;
 123         n = readip(d, &ptr, (void **)&uh, tleft, IPPROTO_UDP);
 124         if (n == -1 || n < sizeof(*uh) || n != ntohs(uh->uh_ulen)) {
 125                 free(ptr);
 126                 return (-1);
 127         }
 128
 129         if (uh->uh_dport != d->myport) {
 130 #ifdef NET_DEBUG
 131                 if (debug)
 132                         printf("readudp: bad dport %d != %d\n",
 133                                 d->myport, ntohs(uh->uh_dport));
 134 #endif
 135                 free(ptr);
 136                 return (-1);
 137         }
 138
 139 #ifndef UDP_NO_CKSUM
 140         if (uh->uh_sum) {
 141                 struct udpiphdr *ui;
 142                 struct ip *ip;
 143                 struct ip tip;
 144
 145                 n = ntohs(uh->uh_ulen) + sizeof(*ip);
 146
 147                 /* Check checksum (must save and restore ip header) */
 148                 ip = (struct ip *)uh - 1;
 149                 tip = *ip;
 150                 ui = (struct udpiphdr *)ip;
 151                 bzero(&ui->ui_x1, sizeof(ui->ui_x1));
 152                 ui->ui_len = uh->uh_ulen;
 153                 if (in_cksum(ui, n) != 0) {
 154 #ifdef NET_DEBUG
 155                         if (debug)
 156                                 printf("readudp: bad cksum\n");
 157 #endif
 158                         free(ptr);
 159                         return (-1);
 160                 }
 161                 *ip = tip;
 162         }
 163 #endif
 164         if (ntohs(uh->uh_ulen) < sizeof(*uh)) {
 165 #ifdef NET_DEBUG
 166                 if (debug)
 167                         printf("readudp: bad udp len %d < %d\n",
 168                                 ntohs(uh->uh_ulen), (int)sizeof(*uh));
 169 #endif
 170                 free(ptr);
 171                 return (-1);
 172         }
 173
 174         n = (n > (ntohs(uh->uh_ulen) - sizeof(*uh))) ?
 175             ntohs(uh->uh_ulen) - sizeof(*uh) : n;
 176         *pkt = ptr;
 177         *payload = (void *)((uintptr_t)uh + sizeof(*uh));
 178         return (n);
 179 }