178 lines
4.6 KiB
C
178 lines
4.6 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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#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/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(struct iodesc *d, void *pkt, size_t len)
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{
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ssize_t cc;
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struct udpiphdr *ui;
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struct udphdr *uh;
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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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ui = (struct udpiphdr *)pkt - 1;
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bzero(ui, sizeof(*ui));
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uh = (struct udphdr *)pkt - 1;
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len += sizeof(*uh);
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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);
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ui->ui_pr = IPPROTO_UDP;
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ui->ui_len = uh->uh_ulen;
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ui->ui_src = d->myip;
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ui->ui_dst = d->destip;
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#ifndef UDP_NO_CKSUM
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uh->uh_sum = in_cksum(ui, len + sizeof (struct ip));
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#endif
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cc = sendip(d, uh, len, IPPROTO_UDP);
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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(*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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*/
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ssize_t
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readudp(struct iodesc *d, void **pkt, void **payload, time_t tleft)
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{
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ssize_t n;
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struct udphdr *uh;
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void *ptr;
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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 = NULL;
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ptr = NULL;
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n = readip(d, &ptr, (void **)&uh, tleft, IPPROTO_UDP);
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if (n == -1 || n < sizeof(*uh) || n != ntohs(uh->uh_ulen)) {
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free(ptr);
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return (-1);
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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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free(ptr);
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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 *ip;
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struct ip tip;
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n = ntohs(uh->uh_ulen) + sizeof(*ip);
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/* Check checksum (must save and restore ip header) */
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ip = (struct ip *)uh - 1;
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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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free(ptr);
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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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free(ptr);
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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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*pkt = ptr;
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*payload = (void *)((uintptr_t)uh + sizeof(*uh));
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return (n);
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}
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