7d1724976f
so that people do not think it is not working at least basically. Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
444 lines
12 KiB
C
444 lines
12 KiB
C
/*
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* Copyright (c) 1982, 1986, 1988, 1993
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* The Regents of the University of California. All rights reserved.
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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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* @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94
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* ip_icmp.c,v 1.7 1995/05/30 08:09:42 rgrimes Exp
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*/
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#include "qemu/osdep.h"
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#include "slirp.h"
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#include "ip_icmp.h"
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/* The message sent when emulating PING */
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/* Be nice and tell them it's just a pseudo-ping packet */
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static const char icmp_ping_msg[] = "This is a pseudo-PING packet used by Slirp to emulate ICMP ECHO-REQUEST packets.\n";
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/* list of actions for icmp_send_error() on RX of an icmp message */
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static const int icmp_flush[19] = {
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/* ECHO REPLY (0) */ 0,
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1,
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1,
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/* DEST UNREACH (3) */ 1,
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/* SOURCE QUENCH (4)*/ 1,
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/* REDIRECT (5) */ 1,
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1,
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1,
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/* ECHO (8) */ 0,
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/* ROUTERADVERT (9) */ 1,
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/* ROUTERSOLICIT (10) */ 1,
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/* TIME EXCEEDED (11) */ 1,
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/* PARAMETER PROBLEM (12) */ 1,
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/* TIMESTAMP (13) */ 0,
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/* TIMESTAMP REPLY (14) */ 0,
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/* INFO (15) */ 0,
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/* INFO REPLY (16) */ 0,
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/* ADDR MASK (17) */ 0,
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/* ADDR MASK REPLY (18) */ 0
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};
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void icmp_init(Slirp *slirp)
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{
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slirp->icmp.so_next = slirp->icmp.so_prev = &slirp->icmp;
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slirp->icmp_last_so = &slirp->icmp;
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}
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void icmp_cleanup(Slirp *slirp)
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{
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while (slirp->icmp.so_next != &slirp->icmp) {
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icmp_detach(slirp->icmp.so_next);
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}
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}
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static int icmp_send(struct socket *so, struct mbuf *m, int hlen)
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{
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struct ip *ip = mtod(m, struct ip *);
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struct sockaddr_in addr;
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so->s = qemu_socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
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if (so->s == -1) {
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return -1;
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}
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so->so_m = m;
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so->so_faddr = ip->ip_dst;
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so->so_laddr = ip->ip_src;
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so->so_iptos = ip->ip_tos;
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so->so_type = IPPROTO_ICMP;
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so->so_state = SS_ISFCONNECTED;
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so->so_expire = curtime + SO_EXPIRE;
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addr.sin_family = AF_INET;
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addr.sin_addr = so->so_faddr;
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insque(so, &so->slirp->icmp);
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if (sendto(so->s, m->m_data + hlen, m->m_len - hlen, 0,
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(struct sockaddr *)&addr, sizeof(addr)) == -1) {
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DEBUG_MISC((dfd, "icmp_input icmp sendto tx errno = %d-%s\n",
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errno, strerror(errno)));
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icmp_send_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
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icmp_detach(so);
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}
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return 0;
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}
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void icmp_detach(struct socket *so)
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{
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closesocket(so->s);
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sofree(so);
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}
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/*
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* Process a received ICMP message.
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*/
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void
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icmp_input(struct mbuf *m, int hlen)
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{
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register struct icmp *icp;
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register struct ip *ip=mtod(m, struct ip *);
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int icmplen=ip->ip_len;
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Slirp *slirp = m->slirp;
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DEBUG_CALL("icmp_input");
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DEBUG_ARG("m = %p", m);
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DEBUG_ARG("m_len = %d", m->m_len);
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/*
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* Locate icmp structure in mbuf, and check
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* that its not corrupted and of at least minimum length.
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*/
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if (icmplen < ICMP_MINLEN) { /* min 8 bytes payload */
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freeit:
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m_free(m);
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goto end_error;
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}
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m->m_len -= hlen;
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m->m_data += hlen;
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icp = mtod(m, struct icmp *);
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if (cksum(m, icmplen)) {
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goto freeit;
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}
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m->m_len += hlen;
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m->m_data -= hlen;
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DEBUG_ARG("icmp_type = %d", icp->icmp_type);
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switch (icp->icmp_type) {
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case ICMP_ECHO:
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ip->ip_len += hlen; /* since ip_input subtracts this */
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if (ip->ip_dst.s_addr == slirp->vhost_addr.s_addr ||
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ip->ip_dst.s_addr == slirp->vnameserver_addr.s_addr) {
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icmp_reflect(m);
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} else if (slirp->restricted) {
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goto freeit;
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} else {
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struct socket *so;
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struct sockaddr_storage addr;
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if ((so = socreate(slirp)) == NULL) goto freeit;
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if (icmp_send(so, m, hlen) == 0) {
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return;
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}
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if (udp_attach(so, AF_INET) == -1) {
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DEBUG_MISC((dfd,"icmp_input udp_attach errno = %d-%s\n",
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errno,strerror(errno)));
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sofree(so);
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m_free(m);
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goto end_error;
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}
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so->so_m = m;
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so->so_ffamily = AF_INET;
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so->so_faddr = ip->ip_dst;
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so->so_fport = htons(7);
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so->so_lfamily = AF_INET;
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so->so_laddr = ip->ip_src;
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so->so_lport = htons(9);
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so->so_iptos = ip->ip_tos;
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so->so_type = IPPROTO_ICMP;
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so->so_state = SS_ISFCONNECTED;
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/* Send the packet */
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addr = so->fhost.ss;
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sotranslate_out(so, &addr);
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if(sendto(so->s, icmp_ping_msg, strlen(icmp_ping_msg), 0,
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(struct sockaddr *)&addr, sockaddr_size(&addr)) == -1) {
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DEBUG_MISC((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
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errno,strerror(errno)));
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icmp_send_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
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udp_detach(so);
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}
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} /* if ip->ip_dst.s_addr == alias_addr.s_addr */
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break;
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case ICMP_UNREACH:
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/* XXX? report error? close socket? */
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case ICMP_TIMXCEED:
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case ICMP_PARAMPROB:
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case ICMP_SOURCEQUENCH:
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case ICMP_TSTAMP:
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case ICMP_MASKREQ:
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case ICMP_REDIRECT:
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m_free(m);
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break;
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default:
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m_free(m);
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} /* swith */
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end_error:
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/* m is m_free()'d xor put in a socket xor or given to ip_send */
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return;
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}
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/*
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* Send an ICMP message in response to a situation
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*
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* RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we do).
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* MUST NOT change this header information.
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* MUST NOT reply to a multicast/broadcast IP address.
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* MUST NOT reply to a multicast/broadcast MAC address.
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* MUST reply to only the first fragment.
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*/
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/*
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* Send ICMP_UNREACH back to the source regarding msrc.
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* mbuf *msrc is used as a template, but is NOT m_free()'d.
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* It is reported as the bad ip packet. The header should
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* be fully correct and in host byte order.
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* ICMP fragmentation is illegal. All machines must accept 576 bytes in one
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* packet. The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548
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*/
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#define ICMP_MAXDATALEN (IP_MSS-28)
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void
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icmp_send_error(struct mbuf *msrc, u_char type, u_char code, int minsize,
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const char *message)
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{
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unsigned hlen, shlen, s_ip_len;
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register struct ip *ip;
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register struct icmp *icp;
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register struct mbuf *m;
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DEBUG_CALL("icmp_send_error");
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DEBUG_ARG("msrc = %p", msrc);
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DEBUG_ARG("msrc_len = %d", msrc->m_len);
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if(type!=ICMP_UNREACH && type!=ICMP_TIMXCEED) goto end_error;
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/* check msrc */
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if(!msrc) goto end_error;
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ip = mtod(msrc, struct ip *);
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#ifdef DEBUG
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{ char bufa[20], bufb[20];
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strcpy(bufa, inet_ntoa(ip->ip_src));
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strcpy(bufb, inet_ntoa(ip->ip_dst));
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DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb));
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}
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#endif
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if(ip->ip_off & IP_OFFMASK) goto end_error; /* Only reply to fragment 0 */
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/* Do not reply to source-only IPs */
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if ((ip->ip_src.s_addr & htonl(~(0xf << 28))) == 0) {
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goto end_error;
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}
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shlen=ip->ip_hl << 2;
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s_ip_len=ip->ip_len;
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if(ip->ip_p == IPPROTO_ICMP) {
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icp = (struct icmp *)((char *)ip + shlen);
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/*
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* Assume any unknown ICMP type is an error. This isn't
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* specified by the RFC, but think about it..
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*/
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if(icp->icmp_type>18 || icmp_flush[icp->icmp_type]) goto end_error;
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}
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/* make a copy */
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m = m_get(msrc->slirp);
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if (!m) {
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goto end_error;
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}
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{ int new_m_size;
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new_m_size=sizeof(struct ip )+ICMP_MINLEN+msrc->m_len+ICMP_MAXDATALEN;
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if(new_m_size>m->m_size) m_inc(m, new_m_size);
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}
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memcpy(m->m_data, msrc->m_data, msrc->m_len);
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m->m_len = msrc->m_len; /* copy msrc to m */
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/* make the header of the reply packet */
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ip = mtod(m, struct ip *);
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hlen= sizeof(struct ip ); /* no options in reply */
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/* fill in icmp */
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m->m_data += hlen;
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m->m_len -= hlen;
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icp = mtod(m, struct icmp *);
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if(minsize) s_ip_len=shlen+ICMP_MINLEN; /* return header+8b only */
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else if(s_ip_len>ICMP_MAXDATALEN) /* maximum size */
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s_ip_len=ICMP_MAXDATALEN;
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m->m_len=ICMP_MINLEN+s_ip_len; /* 8 bytes ICMP header */
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/* min. size = 8+sizeof(struct ip)+8 */
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icp->icmp_type = type;
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icp->icmp_code = code;
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icp->icmp_id = 0;
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icp->icmp_seq = 0;
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memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */
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HTONS(icp->icmp_ip.ip_len);
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HTONS(icp->icmp_ip.ip_id);
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HTONS(icp->icmp_ip.ip_off);
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#ifdef DEBUG
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if(message) { /* DEBUG : append message to ICMP packet */
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int message_len;
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char *cpnt;
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message_len=strlen(message);
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if(message_len>ICMP_MAXDATALEN) message_len=ICMP_MAXDATALEN;
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cpnt=(char *)m->m_data+m->m_len;
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memcpy(cpnt, message, message_len);
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m->m_len+=message_len;
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}
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#endif
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icp->icmp_cksum = 0;
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icp->icmp_cksum = cksum(m, m->m_len);
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m->m_data -= hlen;
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m->m_len += hlen;
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/* fill in ip */
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ip->ip_hl = hlen >> 2;
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ip->ip_len = m->m_len;
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ip->ip_tos=((ip->ip_tos & 0x1E) | 0xC0); /* high priority for errors */
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ip->ip_ttl = MAXTTL;
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ip->ip_p = IPPROTO_ICMP;
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ip->ip_dst = ip->ip_src; /* ip addresses */
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ip->ip_src = m->slirp->vhost_addr;
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(void ) ip_output((struct socket *)NULL, m);
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end_error:
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return;
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}
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#undef ICMP_MAXDATALEN
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/*
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* Reflect the ip packet back to the source
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*/
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void
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icmp_reflect(struct mbuf *m)
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{
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register struct ip *ip = mtod(m, struct ip *);
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int hlen = ip->ip_hl << 2;
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int optlen = hlen - sizeof(struct ip );
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register struct icmp *icp;
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/*
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* Send an icmp packet back to the ip level,
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* after supplying a checksum.
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*/
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m->m_data += hlen;
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m->m_len -= hlen;
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icp = mtod(m, struct icmp *);
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icp->icmp_type = ICMP_ECHOREPLY;
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icp->icmp_cksum = 0;
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icp->icmp_cksum = cksum(m, ip->ip_len - hlen);
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m->m_data -= hlen;
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m->m_len += hlen;
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/* fill in ip */
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if (optlen > 0) {
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/*
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* Strip out original options by copying rest of first
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* mbuf's data back, and adjust the IP length.
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*/
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memmove((caddr_t)(ip + 1), (caddr_t)ip + hlen,
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(unsigned )(m->m_len - hlen));
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hlen -= optlen;
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ip->ip_hl = hlen >> 2;
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ip->ip_len -= optlen;
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m->m_len -= optlen;
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}
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ip->ip_ttl = MAXTTL;
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{ /* swap */
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struct in_addr icmp_dst;
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icmp_dst = ip->ip_dst;
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ip->ip_dst = ip->ip_src;
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ip->ip_src = icmp_dst;
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}
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(void ) ip_output((struct socket *)NULL, m);
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}
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void icmp_receive(struct socket *so)
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{
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struct mbuf *m = so->so_m;
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struct ip *ip = mtod(m, struct ip *);
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int hlen = ip->ip_hl << 2;
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u_char error_code;
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struct icmp *icp;
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int id, len;
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m->m_data += hlen;
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m->m_len -= hlen;
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icp = mtod(m, struct icmp *);
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id = icp->icmp_id;
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len = qemu_recv(so->s, icp, m->m_len, 0);
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icp->icmp_id = id;
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m->m_data -= hlen;
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m->m_len += hlen;
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if (len == -1 || len == 0) {
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if (errno == ENETUNREACH) {
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error_code = ICMP_UNREACH_NET;
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} else {
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error_code = ICMP_UNREACH_HOST;
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}
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DEBUG_MISC((dfd, " udp icmp rx errno = %d-%s\n", errno,
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strerror(errno)));
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icmp_send_error(so->so_m, ICMP_UNREACH, error_code, 0, strerror(errno));
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} else {
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icmp_reflect(so->so_m);
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so->so_m = NULL; /* Don't m_free() it again! */
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}
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icmp_detach(so);
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}
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