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2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94
30 * ip_icmp.c,v 1.7 1995/05/30 08:09:42 rgrimes Exp
36 /* The message sent when emulating PING */
37 /* Be nice and tell them it's just a pseudo-ping packet */
38 static const char icmp_ping_msg
[] = "This is a pseudo-PING packet used by Slirp to emulate ICMP ECHO-REQUEST packets.\n";
40 /* list of actions for icmp_error() on RX of an icmp message */
41 static const int icmp_flush
[19] = {
42 /* ECHO REPLY (0) */ 0,
45 /* DEST UNREACH (3) */ 1,
46 /* SOURCE QUENCH (4)*/ 1,
51 /* ROUTERADVERT (9) */ 1,
52 /* ROUTERSOLICIT (10) */ 1,
53 /* TIME EXCEEDED (11) */ 1,
54 /* PARAMETER PROBLEM (12) */ 1,
55 /* TIMESTAMP (13) */ 0,
56 /* TIMESTAMP REPLY (14) */ 0,
58 /* INFO REPLY (16) */ 0,
59 /* ADDR MASK (17) */ 0,
60 /* ADDR MASK REPLY (18) */ 0
63 void icmp_init(Slirp
*slirp
)
65 slirp
->icmp
.so_next
= slirp
->icmp
.so_prev
= &slirp
->icmp
;
66 slirp
->icmp_last_so
= &slirp
->icmp
;
69 void icmp_cleanup(Slirp
*slirp
)
71 while (slirp
->icmp
.so_next
!= &slirp
->icmp
) {
72 icmp_detach(slirp
->icmp
.so_next
);
76 static int icmp_send(struct socket
*so
, struct mbuf
*m
, int hlen
)
78 struct ip
*ip
= mtod(m
, struct ip
*);
79 struct sockaddr_in addr
;
81 so
->s
= qemu_socket(AF_INET
, SOCK_DGRAM
, IPPROTO_ICMP
);
87 so
->so_faddr
= ip
->ip_dst
;
88 so
->so_laddr
= ip
->ip_src
;
89 so
->so_iptos
= ip
->ip_tos
;
90 so
->so_type
= IPPROTO_ICMP
;
91 so
->so_state
= SS_ISFCONNECTED
;
92 so
->so_expire
= curtime
+ SO_EXPIRE
;
94 addr
.sin_family
= AF_INET
;
95 addr
.sin_addr
= so
->so_faddr
;
97 insque(so
, &so
->slirp
->icmp
);
99 if (sendto(so
->s
, m
->m_data
+ hlen
, m
->m_len
- hlen
, 0,
100 (struct sockaddr
*)&addr
, sizeof(addr
)) == -1) {
101 DEBUG_MISC((dfd
, "icmp_input icmp sendto tx errno = %d-%s\n",
102 errno
, strerror(errno
)));
103 icmp_error(m
, ICMP_UNREACH
, ICMP_UNREACH_NET
, 0, strerror(errno
));
110 void icmp_detach(struct socket
*so
)
117 * Process a received ICMP message.
120 icmp_input(struct mbuf
*m
, int hlen
)
122 register struct icmp
*icp
;
123 register struct ip
*ip
=mtod(m
, struct ip
*);
124 int icmplen
=ip
->ip_len
;
125 Slirp
*slirp
= m
->slirp
;
127 DEBUG_CALL("icmp_input");
128 DEBUG_ARG("m = %p", m
);
129 DEBUG_ARG("m_len = %d", m
->m_len
);
132 * Locate icmp structure in mbuf, and check
133 * that its not corrupted and of at least minimum length.
135 if (icmplen
< ICMP_MINLEN
) { /* min 8 bytes payload */
143 icp
= mtod(m
, struct icmp
*);
144 if (cksum(m
, icmplen
)) {
150 DEBUG_ARG("icmp_type = %d", icp
->icmp_type
);
151 switch (icp
->icmp_type
) {
153 ip
->ip_len
+= hlen
; /* since ip_input subtracts this */
154 if (ip
->ip_dst
.s_addr
== slirp
->vhost_addr
.s_addr
) {
156 } else if (slirp
->restricted
) {
160 struct sockaddr_storage addr
;
161 if ((so
= socreate(slirp
)) == NULL
) goto freeit
;
162 if (icmp_send(so
, m
, hlen
) == 0) {
165 if (udp_attach(so
, AF_INET
) == -1) {
166 DEBUG_MISC((dfd
,"icmp_input udp_attach errno = %d-%s\n",
167 errno
,strerror(errno
)));
173 so
->so_ffamily
= AF_INET
;
174 so
->so_faddr
= ip
->ip_dst
;
175 so
->so_fport
= htons(7);
176 so
->so_lfamily
= AF_INET
;
177 so
->so_laddr
= ip
->ip_src
;
178 so
->so_lport
= htons(9);
179 so
->so_iptos
= ip
->ip_tos
;
180 so
->so_type
= IPPROTO_ICMP
;
181 so
->so_state
= SS_ISFCONNECTED
;
183 /* Send the packet */
185 sotranslate_out(so
, &addr
);
187 if(sendto(so
->s
, icmp_ping_msg
, strlen(icmp_ping_msg
), 0,
188 (struct sockaddr
*)&addr
, sizeof(addr
)) == -1) {
189 DEBUG_MISC((dfd
,"icmp_input udp sendto tx errno = %d-%s\n",
190 errno
,strerror(errno
)));
191 icmp_error(m
, ICMP_UNREACH
,ICMP_UNREACH_NET
, 0,strerror(errno
));
194 } /* if ip->ip_dst.s_addr == alias_addr.s_addr */
197 /* XXX? report error? close socket? */
200 case ICMP_SOURCEQUENCH
:
212 /* m is m_free()'d xor put in a socket xor or given to ip_send */
218 * Send an ICMP message in response to a situation
220 * RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we do).
221 * MUST NOT change this header information.
222 * MUST NOT reply to a multicast/broadcast IP address.
223 * MUST NOT reply to a multicast/broadcast MAC address.
224 * MUST reply to only the first fragment.
227 * Send ICMP_UNREACH back to the source regarding msrc.
228 * mbuf *msrc is used as a template, but is NOT m_free()'d.
229 * It is reported as the bad ip packet. The header should
230 * be fully correct and in host byte order.
231 * ICMP fragmentation is illegal. All machines must accept 576 bytes in one
232 * packet. The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548
235 #define ICMP_MAXDATALEN (IP_MSS-28)
237 icmp_error(struct mbuf
*msrc
, u_char type
, u_char code
, int minsize
,
240 unsigned hlen
, shlen
, s_ip_len
;
241 register struct ip
*ip
;
242 register struct icmp
*icp
;
243 register struct mbuf
*m
;
245 DEBUG_CALL("icmp_error");
246 DEBUG_ARG("msrc = %p", msrc
);
247 DEBUG_ARG("msrc_len = %d", msrc
->m_len
);
249 if(type
!=ICMP_UNREACH
&& type
!=ICMP_TIMXCEED
) goto end_error
;
252 if(!msrc
) goto end_error
;
253 ip
= mtod(msrc
, struct ip
*);
255 { char bufa
[20], bufb
[20];
256 strcpy(bufa
, inet_ntoa(ip
->ip_src
));
257 strcpy(bufb
, inet_ntoa(ip
->ip_dst
));
258 DEBUG_MISC((dfd
, " %.16s to %.16s\n", bufa
, bufb
));
261 if(ip
->ip_off
& IP_OFFMASK
) goto end_error
; /* Only reply to fragment 0 */
263 /* Do not reply to source-only IPs */
264 if ((ip
->ip_src
.s_addr
& htonl(~(0xf << 28))) == 0) {
268 shlen
=ip
->ip_hl
<< 2;
270 if(ip
->ip_p
== IPPROTO_ICMP
) {
271 icp
= (struct icmp
*)((char *)ip
+ shlen
);
273 * Assume any unknown ICMP type is an error. This isn't
274 * specified by the RFC, but think about it..
276 if(icp
->icmp_type
>18 || icmp_flush
[icp
->icmp_type
]) goto end_error
;
280 m
= m_get(msrc
->slirp
);
286 new_m_size
=sizeof(struct ip
)+ICMP_MINLEN
+msrc
->m_len
+ICMP_MAXDATALEN
;
287 if(new_m_size
>m
->m_size
) m_inc(m
, new_m_size
);
289 memcpy(m
->m_data
, msrc
->m_data
, msrc
->m_len
);
290 m
->m_len
= msrc
->m_len
; /* copy msrc to m */
292 /* make the header of the reply packet */
293 ip
= mtod(m
, struct ip
*);
294 hlen
= sizeof(struct ip
); /* no options in reply */
300 icp
= mtod(m
, struct icmp
*);
302 if(minsize
) s_ip_len
=shlen
+ICMP_MINLEN
; /* return header+8b only */
303 else if(s_ip_len
>ICMP_MAXDATALEN
) /* maximum size */
304 s_ip_len
=ICMP_MAXDATALEN
;
306 m
->m_len
=ICMP_MINLEN
+s_ip_len
; /* 8 bytes ICMP header */
308 /* min. size = 8+sizeof(struct ip)+8 */
310 icp
->icmp_type
= type
;
311 icp
->icmp_code
= code
;
315 memcpy(&icp
->icmp_ip
, msrc
->m_data
, s_ip_len
); /* report the ip packet */
316 HTONS(icp
->icmp_ip
.ip_len
);
317 HTONS(icp
->icmp_ip
.ip_id
);
318 HTONS(icp
->icmp_ip
.ip_off
);
321 if(message
) { /* DEBUG : append message to ICMP packet */
324 message_len
=strlen(message
);
325 if(message_len
>ICMP_MAXDATALEN
) message_len
=ICMP_MAXDATALEN
;
326 cpnt
=(char *)m
->m_data
+m
->m_len
;
327 memcpy(cpnt
, message
, message_len
);
328 m
->m_len
+=message_len
;
333 icp
->icmp_cksum
= cksum(m
, m
->m_len
);
339 ip
->ip_hl
= hlen
>> 2;
340 ip
->ip_len
= m
->m_len
;
342 ip
->ip_tos
=((ip
->ip_tos
& 0x1E) | 0xC0); /* high priority for errors */
345 ip
->ip_p
= IPPROTO_ICMP
;
346 ip
->ip_dst
= ip
->ip_src
; /* ip addresses */
347 ip
->ip_src
= m
->slirp
->vhost_addr
;
349 (void ) ip_output((struct socket
*)NULL
, m
);
354 #undef ICMP_MAXDATALEN
357 * Reflect the ip packet back to the source
360 icmp_reflect(struct mbuf
*m
)
362 register struct ip
*ip
= mtod(m
, struct ip
*);
363 int hlen
= ip
->ip_hl
<< 2;
364 int optlen
= hlen
- sizeof(struct ip
);
365 register struct icmp
*icp
;
368 * Send an icmp packet back to the ip level,
369 * after supplying a checksum.
373 icp
= mtod(m
, struct icmp
*);
375 icp
->icmp_type
= ICMP_ECHOREPLY
;
377 icp
->icmp_cksum
= cksum(m
, ip
->ip_len
- hlen
);
385 * Strip out original options by copying rest of first
386 * mbuf's data back, and adjust the IP length.
388 memmove((caddr_t
)(ip
+ 1), (caddr_t
)ip
+ hlen
,
389 (unsigned )(m
->m_len
- hlen
));
391 ip
->ip_hl
= hlen
>> 2;
392 ip
->ip_len
-= optlen
;
398 struct in_addr icmp_dst
;
399 icmp_dst
= ip
->ip_dst
;
400 ip
->ip_dst
= ip
->ip_src
;
401 ip
->ip_src
= icmp_dst
;
404 (void ) ip_output((struct socket
*)NULL
, m
);
407 void icmp_receive(struct socket
*so
)
409 struct mbuf
*m
= so
->so_m
;
410 struct ip
*ip
= mtod(m
, struct ip
*);
411 int hlen
= ip
->ip_hl
<< 2;
418 icp
= mtod(m
, struct icmp
*);
421 len
= qemu_recv(so
->s
, icp
, m
->m_len
, 0);
427 if (len
== -1 || len
== 0) {
428 if (errno
== ENETUNREACH
) {
429 error_code
= ICMP_UNREACH_NET
;
431 error_code
= ICMP_UNREACH_HOST
;
433 DEBUG_MISC((dfd
, " udp icmp rx errno = %d-%s\n", errno
,
435 icmp_error(so
->so_m
, ICMP_UNREACH
, error_code
, 0, strerror(errno
));
437 icmp_reflect(so
->so_m
);
438 so
->so_m
= NULL
; /* Don't m_free() it again! */