199767f8919635c4928607450d9e0abb932109ceToomas Soome/* Taken from $NetBSD: net.c,v 1.20 1997/12/26 22:41:30 scottr Exp $ */
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome/*
199767f8919635c4928607450d9e0abb932109ceToomas Soome * Copyright (c) 1992 Regents of the University of California.
199767f8919635c4928607450d9e0abb932109ceToomas Soome * All rights reserved.
199767f8919635c4928607450d9e0abb932109ceToomas Soome *
199767f8919635c4928607450d9e0abb932109ceToomas Soome * This software was developed by the Computer Systems Engineering group
199767f8919635c4928607450d9e0abb932109ceToomas Soome * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
199767f8919635c4928607450d9e0abb932109ceToomas Soome * contributed to Berkeley.
199767f8919635c4928607450d9e0abb932109ceToomas Soome *
199767f8919635c4928607450d9e0abb932109ceToomas Soome * Redistribution and use in source and binary forms, with or without
199767f8919635c4928607450d9e0abb932109ceToomas Soome * modification, are permitted provided that the following conditions
199767f8919635c4928607450d9e0abb932109ceToomas Soome * are met:
199767f8919635c4928607450d9e0abb932109ceToomas Soome * 1. Redistributions of source code must retain the above copyright
199767f8919635c4928607450d9e0abb932109ceToomas Soome * notice, this list of conditions and the following disclaimer.
199767f8919635c4928607450d9e0abb932109ceToomas Soome * 2. Redistributions in binary form must reproduce the above copyright
199767f8919635c4928607450d9e0abb932109ceToomas Soome * notice, this list of conditions and the following disclaimer in the
199767f8919635c4928607450d9e0abb932109ceToomas Soome * documentation and/or other materials provided with the distribution.
199767f8919635c4928607450d9e0abb932109ceToomas Soome * 4. Neither the name of the University nor the names of its contributors
199767f8919635c4928607450d9e0abb932109ceToomas Soome * may be used to endorse or promote products derived from this software
199767f8919635c4928607450d9e0abb932109ceToomas Soome * without specific prior written permission.
199767f8919635c4928607450d9e0abb932109ceToomas Soome *
199767f8919635c4928607450d9e0abb932109ceToomas Soome * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
199767f8919635c4928607450d9e0abb932109ceToomas Soome * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
199767f8919635c4928607450d9e0abb932109ceToomas Soome * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
199767f8919635c4928607450d9e0abb932109ceToomas Soome * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
199767f8919635c4928607450d9e0abb932109ceToomas Soome * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
199767f8919635c4928607450d9e0abb932109ceToomas Soome * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
199767f8919635c4928607450d9e0abb932109ceToomas Soome * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
199767f8919635c4928607450d9e0abb932109ceToomas Soome * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
199767f8919635c4928607450d9e0abb932109ceToomas Soome * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
199767f8919635c4928607450d9e0abb932109ceToomas Soome * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
199767f8919635c4928607450d9e0abb932109ceToomas Soome * SUCH DAMAGE.
199767f8919635c4928607450d9e0abb932109ceToomas Soome *
199767f8919635c4928607450d9e0abb932109ceToomas Soome * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp (LBL)
199767f8919635c4928607450d9e0abb932109ceToomas Soome */
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include <sys/cdefs.h>
199767f8919635c4928607450d9e0abb932109ceToomas Soome__FBSDID("$FreeBSD$");
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include <sys/param.h>
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include <sys/socket.h>
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include <string.h>
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include <net/if.h>
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include <netinet/in.h>
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include <netinet/if_ether.h>
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include <netinet/in_systm.h>
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include <netinet/in_pcb.h>
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include <netinet/ip.h>
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include <netinet/ip_var.h>
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include <netinet/udp.h>
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include <netinet/udp_var.h>
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include "stand.h"
199767f8919635c4928607450d9e0abb932109ceToomas Soome#include "net.h"
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome/* Caller must leave room for ethernet, ip and udp headers in front!! */
199767f8919635c4928607450d9e0abb932109ceToomas Soomessize_t
199767f8919635c4928607450d9e0abb932109ceToomas Soomesendudp(d, pkt, len)
199767f8919635c4928607450d9e0abb932109ceToomas Soome struct iodesc *d;
199767f8919635c4928607450d9e0abb932109ceToomas Soome void *pkt;
199767f8919635c4928607450d9e0abb932109ceToomas Soome size_t len;
199767f8919635c4928607450d9e0abb932109ceToomas Soome{
199767f8919635c4928607450d9e0abb932109ceToomas Soome ssize_t cc;
199767f8919635c4928607450d9e0abb932109ceToomas Soome struct ip *ip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome struct udphdr *uh;
199767f8919635c4928607450d9e0abb932109ceToomas Soome u_char *ea;
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome#ifdef NET_DEBUG
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (debug) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf("sendudp: d=%lx called.\n", (long)d);
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (d) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf("saddr: %s:%d",
199767f8919635c4928607450d9e0abb932109ceToomas Soome inet_ntoa(d->myip), ntohs(d->myport));
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf(" daddr: %s:%d\n",
199767f8919635c4928607450d9e0abb932109ceToomas Soome inet_ntoa(d->destip), ntohs(d->destport));
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome#endif
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome uh = (struct udphdr *)pkt - 1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome ip = (struct ip *)uh - 1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome len += sizeof(*ip) + sizeof(*uh);
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome bzero(ip, sizeof(*ip) + sizeof(*uh));
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome ip->ip_v = IPVERSION; /* half-char */
199767f8919635c4928607450d9e0abb932109ceToomas Soome ip->ip_hl = sizeof(*ip) >> 2; /* half-char */
199767f8919635c4928607450d9e0abb932109ceToomas Soome ip->ip_len = htons(len);
199767f8919635c4928607450d9e0abb932109ceToomas Soome ip->ip_p = IPPROTO_UDP; /* char */
199767f8919635c4928607450d9e0abb932109ceToomas Soome ip->ip_ttl = IPDEFTTL; /* char */
199767f8919635c4928607450d9e0abb932109ceToomas Soome ip->ip_src = d->myip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome ip->ip_dst = d->destip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome ip->ip_sum = in_cksum(ip, sizeof(*ip)); /* short, but special */
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome uh->uh_sport = d->myport;
199767f8919635c4928607450d9e0abb932109ceToomas Soome uh->uh_dport = d->destport;
199767f8919635c4928607450d9e0abb932109ceToomas Soome uh->uh_ulen = htons(len - sizeof(*ip));
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome#ifndef UDP_NO_CKSUM
199767f8919635c4928607450d9e0abb932109ceToomas Soome {
199767f8919635c4928607450d9e0abb932109ceToomas Soome struct udpiphdr *ui;
199767f8919635c4928607450d9e0abb932109ceToomas Soome struct ip tip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome /* Calculate checksum (must save and restore ip header) */
199767f8919635c4928607450d9e0abb932109ceToomas Soome tip = *ip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome ui = (struct udpiphdr *)ip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome bzero(&ui->ui_x1, sizeof(ui->ui_x1));
199767f8919635c4928607450d9e0abb932109ceToomas Soome ui->ui_len = uh->uh_ulen;
199767f8919635c4928607450d9e0abb932109ceToomas Soome uh->uh_sum = in_cksum(ui, len);
199767f8919635c4928607450d9e0abb932109ceToomas Soome *ip = tip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome#endif
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_src.s_addr == 0 ||
199767f8919635c4928607450d9e0abb932109ceToomas Soome netmask == 0 || SAMENET(ip->ip_src, ip->ip_dst, netmask))
199767f8919635c4928607450d9e0abb932109ceToomas Soome ea = arpwhohas(d, ip->ip_dst);
199767f8919635c4928607450d9e0abb932109ceToomas Soome else
199767f8919635c4928607450d9e0abb932109ceToomas Soome ea = arpwhohas(d, gateip);
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome cc = sendether(d, ip, len, ea, ETHERTYPE_IP);
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (cc == -1)
199767f8919635c4928607450d9e0abb932109ceToomas Soome return (-1);
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (cc != len)
199767f8919635c4928607450d9e0abb932109ceToomas Soome panic("sendudp: bad write (%zd != %zd)", cc, len);
199767f8919635c4928607450d9e0abb932109ceToomas Soome return (cc - (sizeof(*ip) + sizeof(*uh)));
199767f8919635c4928607450d9e0abb932109ceToomas Soome}
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome/*
199767f8919635c4928607450d9e0abb932109ceToomas Soome * Receive a UDP packet and validate it is for us.
199767f8919635c4928607450d9e0abb932109ceToomas Soome * Caller leaves room for the headers (Ether, IP, UDP)
199767f8919635c4928607450d9e0abb932109ceToomas Soome */
199767f8919635c4928607450d9e0abb932109ceToomas Soomessize_t
199767f8919635c4928607450d9e0abb932109ceToomas Soomereadudp(d, pkt, len, tleft)
199767f8919635c4928607450d9e0abb932109ceToomas Soome struct iodesc *d;
199767f8919635c4928607450d9e0abb932109ceToomas Soome void *pkt;
199767f8919635c4928607450d9e0abb932109ceToomas Soome size_t len;
199767f8919635c4928607450d9e0abb932109ceToomas Soome time_t tleft;
199767f8919635c4928607450d9e0abb932109ceToomas Soome{
199767f8919635c4928607450d9e0abb932109ceToomas Soome ssize_t n;
199767f8919635c4928607450d9e0abb932109ceToomas Soome size_t hlen;
199767f8919635c4928607450d9e0abb932109ceToomas Soome struct ip *ip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome struct udphdr *uh;
199767f8919635c4928607450d9e0abb932109ceToomas Soome u_int16_t etype; /* host order */
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome#ifdef NET_DEBUG
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (debug)
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf("readudp: called\n");
199767f8919635c4928607450d9e0abb932109ceToomas Soome#endif
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome uh = (struct udphdr *)pkt - 1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome ip = (struct ip *)uh - 1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome n = readether(d, ip, len + sizeof(*ip) + sizeof(*uh), tleft, &etype);
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (n == -1 || n < sizeof(*ip) + sizeof(*uh))
199767f8919635c4928607450d9e0abb932109ceToomas Soome return -1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome /* Ethernet address checks now in readether() */
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome /* Need to respond to ARP requests. */
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (etype == ETHERTYPE_ARP) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome struct arphdr *ah = (void *)ip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (ah->ar_op == htons(ARPOP_REQUEST)) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome /* Send ARP reply */
199767f8919635c4928607450d9e0abb932109ceToomas Soome arp_reply(d, ah);
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome return -1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (etype != ETHERTYPE_IP) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome#ifdef NET_DEBUG
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (debug)
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf("readudp: not IP. ether_type=%x\n", etype);
199767f8919635c4928607450d9e0abb932109ceToomas Soome#endif
199767f8919635c4928607450d9e0abb932109ceToomas Soome return -1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome /* Check ip header */
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (ip->ip_v != IPVERSION ||
199767f8919635c4928607450d9e0abb932109ceToomas Soome ip->ip_p != IPPROTO_UDP) { /* half char */
199767f8919635c4928607450d9e0abb932109ceToomas Soome#ifdef NET_DEBUG
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (debug)
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf("readudp: IP version or not UDP. ip_v=%d ip_p=%d\n", ip->ip_v, ip->ip_p);
199767f8919635c4928607450d9e0abb932109ceToomas Soome#endif
199767f8919635c4928607450d9e0abb932109ceToomas Soome return -1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome hlen = ip->ip_hl << 2;
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (hlen < sizeof(*ip) ||
199767f8919635c4928607450d9e0abb932109ceToomas Soome in_cksum(ip, hlen) != 0) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome#ifdef NET_DEBUG
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (debug)
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf("readudp: short hdr or bad cksum.\n");
199767f8919635c4928607450d9e0abb932109ceToomas Soome#endif
199767f8919635c4928607450d9e0abb932109ceToomas Soome return -1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (n < ntohs(ip->ip_len)) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome#ifdef NET_DEBUG
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (debug)
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf("readudp: bad length %d < %d.\n",
199767f8919635c4928607450d9e0abb932109ceToomas Soome (int)n, ntohs(ip->ip_len));
199767f8919635c4928607450d9e0abb932109ceToomas Soome#endif
199767f8919635c4928607450d9e0abb932109ceToomas Soome return -1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (d->myip.s_addr && ip->ip_dst.s_addr != d->myip.s_addr) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome#ifdef NET_DEBUG
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (debug) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf("readudp: bad saddr %s != ", inet_ntoa(d->myip));
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf("%s\n", inet_ntoa(ip->ip_dst));
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome#endif
199767f8919635c4928607450d9e0abb932109ceToomas Soome return -1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome /* If there were ip options, make them go away */
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (hlen != sizeof(*ip)) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome bcopy(((u_char *)ip) + hlen, uh, len - hlen);
199767f8919635c4928607450d9e0abb932109ceToomas Soome ip->ip_len = htons(sizeof(*ip));
199767f8919635c4928607450d9e0abb932109ceToomas Soome n -= hlen - sizeof(*ip);
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (uh->uh_dport != d->myport) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome#ifdef NET_DEBUG
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (debug)
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf("readudp: bad dport %d != %d\n",
199767f8919635c4928607450d9e0abb932109ceToomas Soome d->myport, ntohs(uh->uh_dport));
199767f8919635c4928607450d9e0abb932109ceToomas Soome#endif
199767f8919635c4928607450d9e0abb932109ceToomas Soome return -1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome#ifndef UDP_NO_CKSUM
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (uh->uh_sum) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome struct udpiphdr *ui;
199767f8919635c4928607450d9e0abb932109ceToomas Soome struct ip tip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome n = ntohs(uh->uh_ulen) + sizeof(*ip);
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (n > RECV_SIZE - ETHER_SIZE) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf("readudp: huge packet, udp len %d\n", (int)n);
199767f8919635c4928607450d9e0abb932109ceToomas Soome return -1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome /* Check checksum (must save and restore ip header) */
199767f8919635c4928607450d9e0abb932109ceToomas Soome tip = *ip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome ui = (struct udpiphdr *)ip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome bzero(&ui->ui_x1, sizeof(ui->ui_x1));
199767f8919635c4928607450d9e0abb932109ceToomas Soome ui->ui_len = uh->uh_ulen;
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (in_cksum(ui, n) != 0) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome#ifdef NET_DEBUG
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (debug)
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf("readudp: bad cksum\n");
199767f8919635c4928607450d9e0abb932109ceToomas Soome#endif
199767f8919635c4928607450d9e0abb932109ceToomas Soome *ip = tip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome return -1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome *ip = tip;
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome#endif
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (ntohs(uh->uh_ulen) < sizeof(*uh)) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome#ifdef NET_DEBUG
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (debug)
199767f8919635c4928607450d9e0abb932109ceToomas Soome printf("readudp: bad udp len %d < %d\n",
199767f8919635c4928607450d9e0abb932109ceToomas Soome ntohs(uh->uh_ulen), (int)sizeof(*uh));
199767f8919635c4928607450d9e0abb932109ceToomas Soome#endif
199767f8919635c4928607450d9e0abb932109ceToomas Soome return -1;
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome n = (n > (ntohs(uh->uh_ulen) - sizeof(*uh))) ?
199767f8919635c4928607450d9e0abb932109ceToomas Soome ntohs(uh->uh_ulen) - sizeof(*uh) : n;
199767f8919635c4928607450d9e0abb932109ceToomas Soome return (n);
199767f8919635c4928607450d9e0abb932109ceToomas Soome}