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/*
* Copyright (c) 1998 The University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
/*
* The IP layer.
*/
#include <oskit/io/netio.h>
#include <oskit/io/bufio.h>
#include <oskit/net/ether.h>
#include <oskit/c/netinet/in.h>
#include <oskit/c/netinet/ip.h>
#include <oskit/c/arpa/inet.h>
#include <oskit/c/string.h>
#include <oskit/fudp.h>
#include "fudp.h"
static unsigned short ipid = 23;
/*
* IP checksum algorithm.
*/
static unsigned short
ipcksum(void *ipv, int len)
{
unsigned short *ip = ipv;
unsigned long sum = 0;
len >>= 1;
while (len--) {
sum += *(ip++);
if (sum > 0xffff)
sum -= 0xffff;
}
return((~sum) & 0x0000ffff);
}
/*
* Send a fudp buf via IP.
* Fill in the IP header and pass to eth_transmit.
* Deal with broadcasting and gateways.
* Note: `buflen' is the length of the fudp buffer, not just the UDP part.
* `from' and `to' are expected to be in network order.
*/
oskit_error_t
ip_send(oskit_netio_t *netio,
const struct in_addr *from,
const struct in_addr *to,
oskit_bufio_t *b,
oskit_size_t blen)
{
oskit_error_t err = 0;
unsigned char eth_broadcast[] = ETHER_BCAST;
unsigned char eth_src[ETHER_ADDR_SIZE];
unsigned char eth_dst[ETHER_ADDR_SIZE];
struct ip *ip;
/*
* Map in the bufio so `ip' points to the IP part.
*/
err = oskit_bufio_map(b, (void **)&ip,
sizeof(struct ether_header),
blen - sizeof(struct ether_header));
if (err)
return err;
/*
* Fill in the IP header.
*/
ip->ip_v = IPVERSION;
ip->ip_hl = (sizeof *ip) >> 2;
ip->ip_tos = 0;
ip->ip_len = htons(blen - sizeof(struct ether_header));
ip->ip_id = ipid++; /* apparently can't leave this
zero or we get dropped by FreeBSD */
ip->ip_off = 0;
ip->ip_ttl = 64;
ip->ip_p = IPPROTO_UDP;
ip->ip_sum = 0;
ip->ip_src.s_addr = from->s_addr; /* already in net order */
ip->ip_dst.s_addr = to->s_addr; /* already in net order */
ip->ip_sum = ipcksum(ip, sizeof *ip);
if (farp_lookup(&ip->ip_dst, eth_dst) != 0 ||
farp_lookup(&ip->ip_src, eth_src) != 0) {
err = OSKIT_EIO; /* XXX whatever */
goto done;
}
if (ip->ip_dst.s_addr == htons(INADDR_BROADCAST)) {
memcpy(eth_dst, eth_broadcast, ETHER_ADDR_SIZE);
goto sendit;
}
#if 0
/* Deal with gateway - maybe should do this a layer up? */
if ((ntohl(ip->src) & ?MYNETMASK?) != (ntohl(ip->dst) & ?MYNETMASK?))
send to the gateway;
#endif
sendit:
err = eth_transmit(netio, eth_src, eth_dst, ETHERTYPE_IP, b, blen);
done:
oskit_bufio_unmap(b, ip,
sizeof(struct ether_header),
blen - sizeof(struct ether_header));
return err;
}
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