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