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/* Taken from $NetBSD: net.c,v 1.20 1997/12/26 22:41:30 scottr Exp $ */
/*
* Copyright (c) 1992 Regents of the University of California.
* All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/param.h>
#include <sys/socket.h>
#include <string.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include "stand.h"
#include "net.h"
/* Caller must leave room for ethernet, ip and udp headers in front!! */
ssize_t
sendudp(struct iodesc *d, void *pkt, size_t len)
{
ssize_t cc;
struct udpiphdr *ui;
struct udphdr *uh;
#ifdef NET_DEBUG
if (debug) {
printf("sendudp: d=%lx called.\n", (long)d);
if (d) {
printf("saddr: %s:%d",
inet_ntoa(d->myip), ntohs(d->myport));
printf(" daddr: %s:%d\n",
inet_ntoa(d->destip), ntohs(d->destport));
}
}
#endif
ui = (struct udpiphdr *)pkt - 1;
bzero(ui, sizeof(*ui));
uh = (struct udphdr *)pkt - 1;
len += sizeof(*uh);
uh->uh_sport = d->myport;
uh->uh_dport = d->destport;
uh->uh_ulen = htons(len);
ui->ui_pr = IPPROTO_UDP;
ui->ui_len = uh->uh_ulen;
ui->ui_src = d->myip;
ui->ui_dst = d->destip;
#ifndef UDP_NO_CKSUM
uh->uh_sum = in_cksum(ui, len + sizeof (struct ip));
#endif
cc = sendip(d, uh, len, IPPROTO_UDP);
if (cc == -1)
return (-1);
if (cc != len)
panic("sendudp: bad write (%zd != %zd)", cc, len);
return (cc - sizeof(*uh));
}
/*
* Receive a UDP packet and validate it is for us.
*/
ssize_t
readudp(struct iodesc *d, void **pkt, void **payload, time_t tleft)
{
ssize_t n;
struct udphdr *uh;
void *ptr;
#ifdef NET_DEBUG
if (debug)
printf("readudp: called\n");
#endif
uh = NULL;
ptr = NULL;
n = readip(d, &ptr, (void **)&uh, tleft, IPPROTO_UDP);
if (n == -1 || n < sizeof(*uh) || n != ntohs(uh->uh_ulen)) {
free(ptr);
return (-1);
}
if (uh->uh_dport != d->myport) {
#ifdef NET_DEBUG
if (debug)
printf("readudp: bad dport %d != %d\n",
d->myport, ntohs(uh->uh_dport));
#endif
free(ptr);
return (-1);
}
#ifndef UDP_NO_CKSUM
if (uh->uh_sum) {
struct udpiphdr *ui;
struct ip *ip;
struct ip tip;
n = ntohs(uh->uh_ulen) + sizeof(*ip);
/* Check checksum (must save and restore ip header) */
ip = (struct ip *)uh - 1;
tip = *ip;
ui = (struct udpiphdr *)ip;
bzero(&ui->ui_x1, sizeof(ui->ui_x1));
ui->ui_len = uh->uh_ulen;
if (in_cksum(ui, n) != 0) {
#ifdef NET_DEBUG
if (debug)
printf("readudp: bad cksum\n");
#endif
free(ptr);
return (-1);
}
*ip = tip;
}
#endif
if (ntohs(uh->uh_ulen) < sizeof(*uh)) {
#ifdef NET_DEBUG
if (debug)
printf("readudp: bad udp len %d < %d\n",
ntohs(uh->uh_ulen), (int)sizeof(*uh));
#endif
free(ptr);
return (-1);
}
n = (n > (ntohs(uh->uh_ulen) - sizeof(*uh))) ?
ntohs(uh->uh_ulen) - sizeof(*uh) : n;
*pkt = ptr;
*payload = (void *)((uintptr_t)uh + sizeof(*uh));
return (n);
}
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