7dd1a7be9e
Update of existing files based on libslirp 4.7.0 code. It compiles and works on Linux (gcc 10.4) and Windows (mingw/msys with gcc 14 and VS2019). Functionality tested on both platforms with Linux guest OS (Firefox shows website). Next step will be the start of the IPv6 integration.
551 lines
16 KiB
C++
551 lines
16 KiB
C++
/* SPDX-License-Identifier: BSD-3-Clause */
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/*
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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 "slirp.h"
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#include "ip_icmp.h"
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#if BX_NETWORKING && BX_NETMOD_SLIRP
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#ifndef _WIN32
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#include <sys/param.h>
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#endif
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#ifndef WITH_ICMP_ERROR_MSG
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#define WITH_ICMP_ERROR_MSG 0
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#endif
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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[] =
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"This is a pseudo-PING packet used by Slirp to emulate ICMP ECHO-REQUEST "
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"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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struct socket *so, *so_next;
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for (so = slirp->icmp.so_next; so != &slirp->icmp; so = so_next) {
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so_next = so->so_next;
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icmp_detach(so);
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}
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}
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/* Send ICMP packet to the Internet, and save it to so_m */
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static int icmp_send(struct socket *so, struct mbuf *m, int hlen)
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{
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Slirp *slirp = m->slirp;
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M_DUP_DEBUG(slirp, m, 0, 0);
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struct ip *ip = mtod(m, struct ip *);
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struct sockaddr_in addr;
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/*
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* The behavior of reading SOCK_DGRAM+IPPROTO_ICMP sockets is inconsistent
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* between host OSes. On Linux, only the ICMP header and payload is
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* included. On macOS/Darwin, the socket acts like a raw socket and
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* includes the IP header as well. On other BSDs, SOCK_DGRAM+IPPROTO_ICMP
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* sockets aren't supported at all, so we treat them like raw sockets. It
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* isn't possible to detect this difference at runtime, so we must use an
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* #ifdef to determine if we need to remove the IP header.
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*/
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#if defined(BSD) && !defined(__GNU__)
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so->so_type = IPPROTO_IP;
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#else
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so->so_type = IPPROTO_ICMP;
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#endif
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so->s = slirp_socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
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if (so->s == -1) {
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if (errno == EAFNOSUPPORT
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|| errno == EPROTONOSUPPORT
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|| errno == EACCES) {
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/* Kernel doesn't support or allow ping sockets. */
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so->so_type = IPPROTO_IP;
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so->s = slirp_socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
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}
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}
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if (so->s == -1) {
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return -1;
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}
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so->slirp->cb->register_poll_fd(so->s, so->slirp->opaque);
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if (slirp_bind_outbound(so, AF_INET) != 0) {
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// bind failed - close socket
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closesocket(so->s);
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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_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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slirp_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("icmp_input icmp sendto tx errno = %d-%s", errno,
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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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so->slirp->cb->unregister_poll_fd(so->s, so->slirp->opaque);
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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 icmp_input(struct mbuf *m, int hlen)
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{
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Slirp *slirp = m->slirp;
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M_DUP_DEBUG(slirp, m, 0, 0);
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struct icmp *icp;
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struct ip *ip = mtod(m, struct ip *);
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int icmplen=ip->ip_len;
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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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int ttl;
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so = socreate(slirp, IPPROTO_ICMP);
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if (icmp_send(so, m, hlen) == 0) {
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/* We could send this as ICMP, good! */
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return;
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}
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/* We could not send this as ICMP, try to send it on UDP echo
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* service (7), wishfully hoping that it is open there. */
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if (udp_attach(so, AF_INET) == -1) {
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DEBUG_MISC("icmp_input udp_attach errno = %d-%s", errno,
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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_state = SS_ISFCONNECTED;
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/* Send the packet */
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addr = so->fhost.ss;
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if (sotranslate_out(so, &addr) < 0) {
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icmp_send_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0,
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strerror(errno));
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udp_detach(so);
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return;
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}
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/*
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* Check for TTL
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*/
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ttl = ip->ip_ttl-1;
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if (ttl <= 0) {
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DEBUG_MISC("udp ttl exceeded");
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icmp_send_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0,
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NULL);
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udp_detach(so);
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break;
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}
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setsockopt(so->s, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl));
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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("icmp_input udp sendto tx errno = %d-%s", errno,
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strerror(errno));
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icmp_send_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0,
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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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} /* switch */
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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.
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* MAY send more (we do). MUST NOT change this header information. MUST NOT reply
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* to a multicast/broadcast IP address. MUST NOT reply to a multicast/broadcast
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* MAC address. 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 icmp_forward_error(struct mbuf *msrc, uint8_t type, uint8_t code, int minsize,
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const char *message, struct in_addr *src)
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{
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unsigned hlen, shlen, s_ip_len;
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struct ip *ip;
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struct icmp *icp;
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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)
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goto end_error;
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/* check msrc */
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if (!msrc)
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goto end_error;
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ip = mtod(msrc, struct ip *);
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if (slirp_debug & DBG_MISC) {
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char addr_src[INET_ADDRSTRLEN];
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char addr_dst[INET_ADDRSTRLEN];
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inet_ntop(AF_INET, &ip->ip_src, addr_src, sizeof(addr_src));
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inet_ntop(AF_INET, &ip->ip_dst, addr_dst, sizeof(addr_dst));
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DEBUG_MISC(" %.16s to %.16s", addr_src, addr_dst);
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}
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if(ip->ip_off & IP_OFFMASK)
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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])
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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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{
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int new_m_size;
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new_m_size =
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sizeof(struct ip ) + ICMP_MINLEN + msrc->m_len + ICMP_MAXDATALEN;
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if (new_m_size > m->m_size)
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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)
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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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if (message && WITH_ICMP_ERROR_MSG) { /* 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)
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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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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 = *src;
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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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void icmp_send_error(struct mbuf *msrc, uint8_t type, uint8_t code, int minsize,
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const char *message)
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{
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icmp_forward_error(msrc, type, code, minsize, message, &msrc->slirp->vhost_addr);
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}
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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 icmp_reflect(struct mbuf *m)
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{
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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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int optlen = hlen - sizeof(struct ip );
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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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|
*/
|
|
memmove((char *)(ip + 1), (char *)ip + hlen,
|
|
(unsigned )(m->m_len - hlen));
|
|
hlen -= optlen;
|
|
ip->ip_hl = hlen >> 2;
|
|
ip->ip_len -= optlen;
|
|
m->m_len -= optlen;
|
|
}
|
|
|
|
ip->ip_ttl = MAXTTL;
|
|
{ /* swap */
|
|
struct in_addr icmp_dst;
|
|
icmp_dst = ip->ip_dst;
|
|
ip->ip_dst = ip->ip_src;
|
|
ip->ip_src = icmp_dst;
|
|
}
|
|
|
|
ip_output((struct socket *)NULL, m);
|
|
}
|
|
|
|
void icmp_receive(struct socket *so)
|
|
{
|
|
struct mbuf *m = so->so_m;
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
int hlen = ip->ip_hl << 2;
|
|
uint8_t error_code;
|
|
struct icmp *icp;
|
|
int id, len;
|
|
|
|
m->m_data += hlen;
|
|
m->m_len -= hlen;
|
|
icp = mtod(m, struct icmp *);
|
|
|
|
id = icp->icmp_id;
|
|
len = recv(so->s, icp, M_ROOM(m), 0);
|
|
|
|
if (so->so_type == IPPROTO_IP) {
|
|
if (len >= (int)sizeof(struct ip)) {
|
|
struct ip *inner_ip = mtod(m, struct ip *);
|
|
int inner_hlen = inner_ip->ip_hl << 2;
|
|
if (inner_hlen > len) {
|
|
len = -1;
|
|
errno = -EINVAL;
|
|
} else {
|
|
len -= inner_hlen;
|
|
memmove(icp, (unsigned char *)icp + inner_hlen, len);
|
|
}
|
|
} else {
|
|
len = -1;
|
|
errno = -EINVAL;
|
|
}
|
|
}
|
|
|
|
icp->icmp_id = id;
|
|
|
|
m->m_data -= hlen;
|
|
m->m_len += hlen;
|
|
|
|
if (len == -1 || len == 0) {
|
|
if (errno == ENETUNREACH) {
|
|
error_code = ICMP_UNREACH_NET;
|
|
} else {
|
|
error_code = ICMP_UNREACH_HOST;
|
|
}
|
|
DEBUG_MISC(" udp icmp rx errno = %d-%s", errno, strerror(errno));
|
|
icmp_send_error(so->so_m, ICMP_UNREACH, error_code, 0, strerror(errno));
|
|
} else {
|
|
icmp_reflect(so->so_m);
|
|
so->so_m = NULL; /* Don't m_free() it again! */
|
|
}
|
|
icmp_detach(so);
|
|
}
|
|
|
|
#endif
|