sys/lib/libsa/ip.c
C | 190 lines | 114 code | 20 blank | 56 comment | 35 complexity | c0f6cabd9d3a1ee2d1991b04371b0839 MD5 | raw file
Possible License(s): MIT, WTFPL, AGPL-1.0, BSD-3-Clause, GPL-3.0, LGPL-2.0, JSON, 0BSD
- /* $NetBSD: ip.c,v 1.2 2011/05/13 23:35:09 nakayama Exp $ */
- /*
- * Copyright (c) 1992 Regents of the University of California.
- * Copyright (c) 2010 Zoltan Arnold NAGY
- * 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. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Lawrence Berkeley Laboratory and its contributors.
- * 4. 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 <net/if.h>
- #include <net/if_ether.h>
- #include <netinet/in.h>
- #include <netinet/in_systm.h>
- #include <netinet/ip.h>
- #include <netinet/ip_var.h>
- #include <netinet/udp.h>
- #include <netinet/udp_var.h>
- #ifdef _STANDALONE
- #include <lib/libkern/libkern.h>
- #else
- #include <string.h>
- #endif
- #include "stand.h"
- #include "net.h"
- /*
- * sends an IP packet, if it's alredy constructed
- */
- static ssize_t
- _sendip(struct iodesc * d, struct ip * ip, size_t len)
- {
- u_char *ea;
- if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_src.s_addr == 0 ||
- netmask == 0 || SAMENET(ip->ip_src, ip->ip_dst, netmask)) {
- ea = arpwhohas(d, ip->ip_dst);
- } else {
- ea = arpwhohas(d, gateip);
- }
- return sendether(d, ip, len, ea, ETHERTYPE_IP);
- }
- /*
- * fills out the IP header
- * Caller must leave room for ethernet, ip and udp headers in front!
- */
- ssize_t
- sendip(struct iodesc * d, void *pkt, size_t len, u_int8_t proto)
- {
- ssize_t cc;
- struct ip *ip;
- ip = (struct ip *) pkt - 1;
- len += sizeof(*ip);
- (void) memset(ip, 0, sizeof(*ip));
- ip->ip_v = IPVERSION;
- ip->ip_hl = sizeof(*ip) >> 2;
- ip->ip_len = htons(len);
- ip->ip_p = proto;
- ip->ip_ttl = IPDEFTTL;
- ip->ip_src = d->myip;
- ip->ip_dst = d->destip;
- ip->ip_sum = ip_cksum(ip, sizeof(*ip));
- cc = _sendip(d, ip, len);
- if (cc == -1)
- return -1;
- if ((size_t) cc != len)
- panic("sendip: bad write (%zd != %zu)", cc, len);
- return (cc - (sizeof(*ip)));
- }
- /*
- * reads an IP packet
- * WARNING: the old version stripped the IP options, if there were
- * any. Because we have absolutely no idea if the upper layer needs
- * these or not, it's best to leave them there.
- *
- * The size returned is the size indicated in the header.
- */
- ssize_t
- readip(struct iodesc * d, void *pkt, size_t len, time_t tleft, u_int8_t proto)
- {
- ssize_t n;
- size_t hlen;
- struct ip *ip;
- u_int16_t etype;
- ip = (struct ip *) pkt - 1;
- n = readether(d, ip, len + sizeof(*ip), tleft, &etype);
- if (n == -1 || (size_t) n < sizeof(*ip))
- return -1;
- if (etype == ETHERTYPE_ARP) {
- struct arphdr *ah = (void *) ip;
- if (ah->ar_op == htons(ARPOP_REQUEST)) {
- /* Send ARP reply */
- arp_reply(d, ah);
- }
- return -1;
- }
- if (etype != ETHERTYPE_IP) {
- #ifdef NET_DEBUG
- if (debug)
- printf("readip: not IP. ether_type=%x\n", etype);
- #endif
- return -1;
- }
- /* Check ip header */
- if (ip->ip_v != IPVERSION ||
- ip->ip_p != proto) { /* half char */
- #ifdef NET_DEBUG
- if (debug) {
- printf("readip: wrong IP version or wrong proto "
- "ip_v=%d ip_p=%d\n", ip->ip_v, ip->ip_p);
- }
- #endif
- return -1;
- }
- hlen = ip->ip_hl << 2;
- if (hlen < sizeof(*ip) || ip_cksum(ip, hlen) != 0) {
- #ifdef NET_DEBUG
- if (debug)
- printf("readip: short hdr or bad cksum.\n");
- #endif
- return -1;
- }
- if (n < ntohs(ip->ip_len)) {
- #ifdef NET_DEBUG
- if (debug)
- printf("readip: bad length %d < %d.\n",
- (int) n, ntohs(ip->ip_len));
- #endif
- return -1;
- }
- if (d->myip.s_addr && ip->ip_dst.s_addr != d->myip.s_addr) {
- #ifdef NET_DEBUG
- if (debug) {
- printf("readip: bad saddr %s != ", inet_ntoa(d->myip));
- printf("%s\n", inet_ntoa(ip->ip_dst));
- }
- #endif
- return -1;
- }
- return (ntohs(ip->ip_len) - 20);
- }