fbbd9655e5
Renumber cluase 4 to 3, per what everybody else did when BSD granted them permission to remove clause 3. My insistance on keeping the same numbering for legal reasons is too pedantic, so give up on that point. Submitted by: Jan Schaumann <jschauma@stevens.edu> Pull Request: https://github.com/freebsd/freebsd/pull/96
273 lines
6.8 KiB
C
273 lines
6.8 KiB
C
/* Taken from $NetBSD: net.c,v 1.20 1997/12/26 22:41:30 scottr Exp $ */
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/*
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* Copyright (c) 1992 Regents of the University of California.
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* All rights reserved.
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*
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* This software was developed by the Computer Systems Engineering group
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* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
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* contributed to Berkeley.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp (LBL)
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/socket.h>
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#include <string.h>
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#include <net/if.h>
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#include <netinet/in.h>
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#include <netinet/if_ether.h>
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#include <netinet/in_systm.h>
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#include <netinet/in_pcb.h>
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#include <netinet/ip.h>
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#include <netinet/ip_var.h>
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#include <netinet/udp.h>
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#include <netinet/udp_var.h>
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#include "stand.h"
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#include "net.h"
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/* Caller must leave room for ethernet, ip and udp headers in front!! */
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ssize_t
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sendudp(d, pkt, len)
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struct iodesc *d;
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void *pkt;
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size_t len;
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{
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ssize_t cc;
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struct ip *ip;
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struct udphdr *uh;
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u_char *ea;
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#ifdef NET_DEBUG
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if (debug) {
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printf("sendudp: d=%lx called.\n", (long)d);
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if (d) {
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printf("saddr: %s:%d",
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inet_ntoa(d->myip), ntohs(d->myport));
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printf(" daddr: %s:%d\n",
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inet_ntoa(d->destip), ntohs(d->destport));
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}
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}
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#endif
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uh = (struct udphdr *)pkt - 1;
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ip = (struct ip *)uh - 1;
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len += sizeof(*ip) + sizeof(*uh);
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bzero(ip, sizeof(*ip) + sizeof(*uh));
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ip->ip_v = IPVERSION; /* half-char */
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ip->ip_hl = sizeof(*ip) >> 2; /* half-char */
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ip->ip_len = htons(len);
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ip->ip_p = IPPROTO_UDP; /* char */
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ip->ip_ttl = IPDEFTTL; /* char */
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ip->ip_src = d->myip;
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ip->ip_dst = d->destip;
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ip->ip_sum = in_cksum(ip, sizeof(*ip)); /* short, but special */
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uh->uh_sport = d->myport;
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uh->uh_dport = d->destport;
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uh->uh_ulen = htons(len - sizeof(*ip));
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#ifndef UDP_NO_CKSUM
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{
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struct udpiphdr *ui;
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struct ip tip;
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/* Calculate checksum (must save and restore ip header) */
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tip = *ip;
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ui = (struct udpiphdr *)ip;
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bzero(&ui->ui_x1, sizeof(ui->ui_x1));
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ui->ui_len = uh->uh_ulen;
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uh->uh_sum = in_cksum(ui, len);
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*ip = tip;
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}
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#endif
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if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_src.s_addr == 0 ||
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netmask == 0 || SAMENET(ip->ip_src, ip->ip_dst, netmask))
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ea = arpwhohas(d, ip->ip_dst);
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else
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ea = arpwhohas(d, gateip);
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cc = sendether(d, ip, len, ea, ETHERTYPE_IP);
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if (cc == -1)
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return (-1);
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if (cc != len)
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panic("sendudp: bad write (%zd != %zd)", cc, len);
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return (cc - (sizeof(*ip) + sizeof(*uh)));
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}
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/*
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* Receive a UDP packet and validate it is for us.
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* Caller leaves room for the headers (Ether, IP, UDP)
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*/
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ssize_t
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readudp(d, pkt, len, tleft)
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struct iodesc *d;
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void *pkt;
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size_t len;
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time_t tleft;
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{
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ssize_t n;
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size_t hlen;
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struct ip *ip;
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struct udphdr *uh;
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u_int16_t etype; /* host order */
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#ifdef NET_DEBUG
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if (debug)
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printf("readudp: called\n");
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#endif
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uh = (struct udphdr *)pkt - 1;
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ip = (struct ip *)uh - 1;
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n = readether(d, ip, len + sizeof(*ip) + sizeof(*uh), tleft, &etype);
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if (n == -1 || n < sizeof(*ip) + sizeof(*uh))
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return -1;
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/* Ethernet address checks now in readether() */
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/* Need to respond to ARP requests. */
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if (etype == ETHERTYPE_ARP) {
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struct arphdr *ah = (void *)ip;
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if (ah->ar_op == htons(ARPOP_REQUEST)) {
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/* Send ARP reply */
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arp_reply(d, ah);
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}
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return -1;
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}
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if (etype != ETHERTYPE_IP) {
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#ifdef NET_DEBUG
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if (debug)
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printf("readudp: not IP. ether_type=%x\n", etype);
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#endif
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return -1;
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}
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/* Check ip header */
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if (ip->ip_v != IPVERSION ||
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ip->ip_p != IPPROTO_UDP) { /* half char */
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#ifdef NET_DEBUG
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if (debug)
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printf("readudp: IP version or not UDP. ip_v=%d ip_p=%d\n", ip->ip_v, ip->ip_p);
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#endif
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return -1;
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}
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hlen = ip->ip_hl << 2;
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if (hlen < sizeof(*ip) ||
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in_cksum(ip, hlen) != 0) {
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#ifdef NET_DEBUG
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if (debug)
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printf("readudp: short hdr or bad cksum.\n");
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#endif
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return -1;
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}
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if (n < ntohs(ip->ip_len)) {
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#ifdef NET_DEBUG
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if (debug)
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printf("readudp: bad length %d < %d.\n",
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(int)n, ntohs(ip->ip_len));
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#endif
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return -1;
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}
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if (d->myip.s_addr && ip->ip_dst.s_addr != d->myip.s_addr) {
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#ifdef NET_DEBUG
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if (debug) {
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printf("readudp: bad saddr %s != ", inet_ntoa(d->myip));
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printf("%s\n", inet_ntoa(ip->ip_dst));
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}
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#endif
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return -1;
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}
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/* If there were ip options, make them go away */
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if (hlen != sizeof(*ip)) {
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bcopy(((u_char *)ip) + hlen, uh, len - hlen);
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ip->ip_len = htons(sizeof(*ip));
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n -= hlen - sizeof(*ip);
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}
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if (uh->uh_dport != d->myport) {
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#ifdef NET_DEBUG
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if (debug)
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printf("readudp: bad dport %d != %d\n",
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d->myport, ntohs(uh->uh_dport));
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#endif
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return -1;
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}
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#ifndef UDP_NO_CKSUM
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if (uh->uh_sum) {
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struct udpiphdr *ui;
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struct ip tip;
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n = ntohs(uh->uh_ulen) + sizeof(*ip);
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if (n > RECV_SIZE - ETHER_SIZE) {
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printf("readudp: huge packet, udp len %d\n", (int)n);
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return -1;
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}
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/* Check checksum (must save and restore ip header) */
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tip = *ip;
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ui = (struct udpiphdr *)ip;
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bzero(&ui->ui_x1, sizeof(ui->ui_x1));
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ui->ui_len = uh->uh_ulen;
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if (in_cksum(ui, n) != 0) {
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#ifdef NET_DEBUG
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if (debug)
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printf("readudp: bad cksum\n");
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#endif
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*ip = tip;
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return -1;
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}
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*ip = tip;
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}
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#endif
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if (ntohs(uh->uh_ulen) < sizeof(*uh)) {
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#ifdef NET_DEBUG
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if (debug)
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printf("readudp: bad udp len %d < %d\n",
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ntohs(uh->uh_ulen), (int)sizeof(*uh));
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#endif
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return -1;
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}
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n = (n > (ntohs(uh->uh_ulen) - sizeof(*uh))) ?
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ntohs(uh->uh_ulen) - sizeof(*uh) : n;
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return (n);
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}
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