[qemu.git] / slirp / ip_icmp.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_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_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, sizeof(addr)) == -1) {
	DEBUG_MISC((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
		    errno,strerror(errno)));
	icmp_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_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_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_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);
}
Commit	Line	Data
f0cbd3ec FB	1	/*
	2	* Copyright (c) 1982, 1986, 1988, 1993
	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	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.
2f5f8996	13	* 3. Neither the name of the University nor the names of its contributors
f0cbd3ec FB	14	* may be used to endorse or promote products derived from this software
	15	* without specific prior written permission.
	16	*
	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
	27	* SUCH DAMAGE.
	28	*
	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
	31	*/
	32
7df7482b	33	#include "qemu/osdep.h"
f0cbd3ec FB	34	#include "slirp.h"
	35	#include "ip_icmp.h"
	36
f0cbd3ec	37	/* The message sent when emulating PING */
7878ff6b	38	/* Be nice and tell them it's just a pseudo-ping packet */
7ca699c8	39	static const char icmp_ping_msg[] = "This is a pseudo-PING packet used by Slirp to emulate ICMP ECHO-REQUEST packets.\n";
f0cbd3ec FB	40
f0cbd3ec FB	41	/* list of actions for icmp_error() on RX of an icmp message */
9634d903	42	static const int icmp_flush[19] = {
f0cbd3ec FB	43	/* ECHO REPLY (0) */ 0,
	44	1,
	45	1,
	46	/* DEST UNREACH (3) */ 1,
	47	/* SOURCE QUENCH (4)*/ 1,
	48	/* REDIRECT (5) */ 1,
	49	1,
	50	1,
	51	/* ECHO (8) */ 0,
	52	/* ROUTERADVERT (9) */ 1,
	53	/* ROUTERSOLICIT (10) */ 1,
	54	/* TIME EXCEEDED (11) */ 1,
	55	/* PARAMETER PROBLEM (12) */ 1,
	56	/* TIMESTAMP (13) */ 0,
	57	/* TIMESTAMP REPLY (14) */ 0,
	58	/* INFO (15) */ 0,
	59	/* INFO REPLY (16) */ 0,
	60	/* ADDR MASK (17) */ 0,
5fafdf24	61	/* ADDR MASK REPLY (18) */ 0
f0cbd3ec FB	62	};
f0cbd3ec FB	63
e6d43cfb JK	64	void icmp_init(Slirp *slirp)
	65	{
	66	slirp->icmp.so_next = slirp->icmp.so_prev = &slirp->icmp;
	67	slirp->icmp_last_so = &slirp->icmp;
	68	}
	69
a68adc22 JK	70	void icmp_cleanup(Slirp *slirp)
	71	{
	72	while (slirp->icmp.so_next != &slirp->icmp) {
	73	icmp_detach(slirp->icmp.so_next);
	74	}
	75	}
	76
e6d43cfb JK	77	static int icmp_send(struct socket so, struct mbuf m, int hlen)
	78	{
	79	struct ip ip = mtod(m, struct ip );
	80	struct sockaddr_in addr;
	81
	82	so->s = qemu_socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
	83	if (so->s == -1) {
	84	return -1;
	85	}
	86
	87	so->so_m = m;
	88	so->so_faddr = ip->ip_dst;
	89	so->so_laddr = ip->ip_src;
	90	so->so_iptos = ip->ip_tos;
	91	so->so_type = IPPROTO_ICMP;
	92	so->so_state = SS_ISFCONNECTED;
	93	so->so_expire = curtime + SO_EXPIRE;
	94
	95	addr.sin_family = AF_INET;
	96	addr.sin_addr = so->so_faddr;
	97
	98	insque(so, &so->slirp->icmp);
	99
	100	if (sendto(so->s, m->m_data + hlen, m->m_len - hlen, 0,
	101	(struct sockaddr *)&addr, sizeof(addr)) == -1) {
	102	DEBUG_MISC((dfd, "icmp_input icmp sendto tx errno = %d-%s\n",
	103	errno, strerror(errno)));
	104	icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
	105	icmp_detach(so);
	106	}
	107
	108	return 0;
	109	}
	110
	111	void icmp_detach(struct socket *so)
	112	{
	113	closesocket(so->s);
	114	sofree(so);
	115	}
	116
f0cbd3ec FB	117	/*
	118	* Process a received ICMP message.
	119	*/
	120	void
511d2b14	121	icmp_input(struct mbuf *m, int hlen)
f0cbd3ec FB	122	{
	123	register struct icmp *icp;
	124	register struct ip ip=mtod(m, struct ip );
	125	int icmplen=ip->ip_len;
460fec67	126	Slirp *slirp = m->slirp;
5fafdf24	127
f0cbd3ec	128	DEBUG_CALL("icmp_input");
ecc804ca	129	DEBUG_ARG("m = %p", m);
f0cbd3ec FB	130	DEBUG_ARG("m_len = %d", m->m_len);
f0cbd3ec FB	131
f0cbd3ec FB	132	/*
	133	* Locate icmp structure in mbuf, and check
	134	* that its not corrupted and of at least minimum length.
	135	*/
	136	if (icmplen < ICMP_MINLEN) { /* min 8 bytes payload */
f0cbd3ec	137	freeit:
3acccfc6	138	m_free(m);
f0cbd3ec FB	139	goto end_error;
	140	}
	141
	142	m->m_len -= hlen;
	143	m->m_data += hlen;
	144	icp = mtod(m, struct icmp *);
	145	if (cksum(m, icmplen)) {
f0cbd3ec FB	146	goto freeit;
	147	}
	148	m->m_len += hlen;
	149	m->m_data -= hlen;
3b46e624	150
f0cbd3ec FB	151	DEBUG_ARG("icmp_type = %d", icp->icmp_type);
	152	switch (icp->icmp_type) {
	153	case ICMP_ECHO:
f0cbd3ec	154	ip->ip_len += hlen; /* since ip_input subtracts this */
460fec67	155	if (ip->ip_dst.s_addr == slirp->vhost_addr.s_addr) {
f0cbd3ec	156	icmp_reflect(m);
12b513d8 JK	157	} else if (slirp->restricted) {
12b513d8 JK	158	goto freeit;
f0cbd3ec FB	159	} else {
f0cbd3ec FB	160	struct socket *so;
5379229a	161	struct sockaddr_storage addr;
460fec67	162	if ((so = socreate(slirp)) == NULL) goto freeit;
e6d43cfb JK	163	if (icmp_send(so, m, hlen) == 0) {
	164	return;
	165	}
9b5a30dc	166	if (udp_attach(so, AF_INET) == -1) {
5fafdf24	167	DEBUG_MISC((dfd,"icmp_input udp_attach errno = %d-%s\n",
f0cbd3ec FB	168	errno,strerror(errno)));
	169	sofree(so);
	170	m_free(m);
	171	goto end_error;
	172	}
	173	so->so_m = m;
eae303ff	174	so->so_ffamily = AF_INET;
f0cbd3ec FB	175	so->so_faddr = ip->ip_dst;
f0cbd3ec FB	176	so->so_fport = htons(7);
eae303ff	177	so->so_lfamily = AF_INET;
f0cbd3ec FB	178	so->so_laddr = ip->ip_src;
	179	so->so_lport = htons(9);
	180	so->so_iptos = ip->ip_tos;
	181	so->so_type = IPPROTO_ICMP;
	182	so->so_state = SS_ISFCONNECTED;
3b46e624	183
f0cbd3ec	184	/* Send the packet */
5379229a GS	185	addr = so->fhost.ss;
	186	sotranslate_out(so, &addr);
	187
f0cbd3ec FB	188	if(sendto(so->s, icmp_ping_msg, strlen(icmp_ping_msg), 0,
	189	(struct sockaddr *)&addr, sizeof(addr)) == -1) {
	190	DEBUG_MISC((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
	191	errno,strerror(errno)));
5fafdf24	192	icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));
f0cbd3ec FB	193	udp_detach(so);
f0cbd3ec FB	194	}
8dbca8dd	195	} /* if ip->ip_dst.s_addr == alias_addr.s_addr */
f0cbd3ec FB	196	break;
	197	case ICMP_UNREACH:
	198	/* XXX? report error? close socket? */
	199	case ICMP_TIMXCEED:
	200	case ICMP_PARAMPROB:
	201	case ICMP_SOURCEQUENCH:
	202	case ICMP_TSTAMP:
	203	case ICMP_MASKREQ:
	204	case ICMP_REDIRECT:
3acccfc6	205	m_free(m);
f0cbd3ec	206	break;
3b46e624	207
f0cbd3ec	208	default:
3acccfc6	209	m_free(m);
f0cbd3ec FB	210	} /* swith */
	211
	212	end_error:
	213	/* m is m_free()'d xor put in a socket xor or given to ip_send */
	214	return;
	215	}
	216
	217
	218	/*
	219	* Send an ICMP message in response to a situation
	220	*
	221	* RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we do).
	222	* MUST NOT change this header information.
	223	* MUST NOT reply to a multicast/broadcast IP address.
	224	* MUST NOT reply to a multicast/broadcast MAC address.
	225	* MUST reply to only the first fragment.
	226	*/
	227	/*
	228	* Send ICMP_UNREACH back to the source regarding msrc.
	229	* mbuf *msrc is used as a template, but is NOT m_free()'d.
	230	* It is reported as the bad ip packet. The header should
	231	* be fully correct and in host byte order.
5fafdf24	232	* ICMP fragmentation is illegal. All machines must accept 576 bytes in one
f0cbd3ec FB	233	* packet. The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548
	234	*/
	235
	236	#define ICMP_MAXDATALEN (IP_MSS-28)
	237	void
7ccfb2eb BS	238	icmp_error(struct mbuf *msrc, u_char type, u_char code, int minsize,
7ccfb2eb BS	239	const char *message)
f0cbd3ec FB	240	{
	241	unsigned hlen, shlen, s_ip_len;
	242	register struct ip *ip;
	243	register struct icmp *icp;
	244	register struct mbuf *m;
	245
	246	DEBUG_CALL("icmp_error");
ecc804ca	247	DEBUG_ARG("msrc = %p", msrc);
f0cbd3ec FB	248	DEBUG_ARG("msrc_len = %d", msrc->m_len);
	249
	250	if(type!=ICMP_UNREACH && type!=ICMP_TIMXCEED) goto end_error;
	251
	252	/* check msrc */
	253	if(!msrc) goto end_error;
	254	ip = mtod(msrc, struct ip *);
eb38c52c	255	#ifdef DEBUG
f0cbd3ec FB	256	{ char bufa[20], bufb[20];
	257	strcpy(bufa, inet_ntoa(ip->ip_src));
	258	strcpy(bufb, inet_ntoa(ip->ip_dst));
	259	DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb));
	260	}
	261	#endif
	262	if(ip->ip_off & IP_OFFMASK) goto end_error; /* Only reply to fragment 0 */
	263
6612db12 JK	264	/* Do not reply to source-only IPs */
	265	if ((ip->ip_src.s_addr & htonl(~(0xf << 28))) == 0) {
	266	goto end_error;
	267	}
	268
f0cbd3ec FB	269	shlen=ip->ip_hl << 2;
	270	s_ip_len=ip->ip_len;
	271	if(ip->ip_p == IPPROTO_ICMP) {
	272	icp = (struct icmp )((char )ip + shlen);
	273	/*
	274	* Assume any unknown ICMP type is an error. This isn't
	275	* specified by the RFC, but think about it..
	276	*/
	277	if(icp->icmp_type>18 \|\| icmp_flush[icp->icmp_type]) goto end_error;
	278	}
	279
	280	/* make a copy */
460fec67 JK	281	m = m_get(msrc->slirp);
	282	if (!m) {
	283	goto end_error;
	284	}
	285
f0cbd3ec FB	286	{ int new_m_size;
	287	new_m_size=sizeof(struct ip )+ICMP_MINLEN+msrc->m_len+ICMP_MAXDATALEN;
	288	if(new_m_size>m->m_size) m_inc(m, new_m_size);
	289	}
	290	memcpy(m->m_data, msrc->m_data, msrc->m_len);
	291	m->m_len = msrc->m_len; /* copy msrc to m */
	292
	293	/* make the header of the reply packet */
	294	ip = mtod(m, struct ip *);
	295	hlen= sizeof(struct ip ); /* no options in reply */
3b46e624	296
f0cbd3ec	297	/* fill in icmp */
3b46e624	298	m->m_data += hlen;
f0cbd3ec FB	299	m->m_len -= hlen;
	300
	301	icp = mtod(m, struct icmp *);
	302
	303	if(minsize) s_ip_len=shlen+ICMP_MINLEN; /* return header+8b only */
	304	else if(s_ip_len>ICMP_MAXDATALEN) /* maximum size */
	305	s_ip_len=ICMP_MAXDATALEN;
	306
3b46e624	307	m->m_len=ICMP_MINLEN+s_ip_len; /* 8 bytes ICMP header */
f0cbd3ec FB	308
	309	/* min. size = 8+sizeof(struct ip)+8 */
	310
	311	icp->icmp_type = type;
	312	icp->icmp_code = code;
	313	icp->icmp_id = 0;
	314	icp->icmp_seq = 0;
	315
	316	memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */
	317	HTONS(icp->icmp_ip.ip_len);
	318	HTONS(icp->icmp_ip.ip_id);
	319	HTONS(icp->icmp_ip.ip_off);
	320
eb38c52c	321	#ifdef DEBUG
f0cbd3ec FB	322	if(message) { /* DEBUG : append message to ICMP packet */
	323	int message_len;
	324	char *cpnt;
	325	message_len=strlen(message);
	326	if(message_len>ICMP_MAXDATALEN) message_len=ICMP_MAXDATALEN;
	327	cpnt=(char *)m->m_data+m->m_len;
	328	memcpy(cpnt, message, message_len);
	329	m->m_len+=message_len;
	330	}
	331	#endif
	332
	333	icp->icmp_cksum = 0;
	334	icp->icmp_cksum = cksum(m, m->m_len);
	335
	336	m->m_data -= hlen;
	337	m->m_len += hlen;
	338
	339	/* fill in ip */
	340	ip->ip_hl = hlen >> 2;
	341	ip->ip_len = m->m_len;
3b46e624	342
f0cbd3ec FB	343	ip->ip_tos=((ip->ip_tos & 0x1E) \| 0xC0); /* high priority for errors */
	344
	345	ip->ip_ttl = MAXTTL;
	346	ip->ip_p = IPPROTO_ICMP;
a93cf9df	347	ip->ip_dst = ip->ip_src; /* ip addresses */
460fec67	348	ip->ip_src = m->slirp->vhost_addr;
f0cbd3ec FB	349
f0cbd3ec FB	350	(void ) ip_output((struct socket *)NULL, m);
3b46e624	351
f0cbd3ec FB	352	end_error:
	353	return;
	354	}
	355	#undef ICMP_MAXDATALEN
	356
	357	/*
	358	* Reflect the ip packet back to the source
	359	*/
	360	void
511d2b14	361	icmp_reflect(struct mbuf *m)
f0cbd3ec FB	362	{
	363	register struct ip ip = mtod(m, struct ip );
	364	int hlen = ip->ip_hl << 2;
	365	int optlen = hlen - sizeof(struct ip );
	366	register struct icmp *icp;
	367
	368	/*
	369	* Send an icmp packet back to the ip level,
	370	* after supplying a checksum.
	371	*/
	372	m->m_data += hlen;
	373	m->m_len -= hlen;
	374	icp = mtod(m, struct icmp *);
	375
e6d43cfb	376	icp->icmp_type = ICMP_ECHOREPLY;
f0cbd3ec FB	377	icp->icmp_cksum = 0;
	378	icp->icmp_cksum = cksum(m, ip->ip_len - hlen);
	379
	380	m->m_data -= hlen;
	381	m->m_len += hlen;
	382
	383	/* fill in ip */
	384	if (optlen > 0) {
	385	/*
	386	* Strip out original options by copying rest of first
	387	* mbuf's data back, and adjust the IP length.
	388	*/
	389	memmove((caddr_t)(ip + 1), (caddr_t)ip + hlen,
	390	(unsigned )(m->m_len - hlen));
	391	hlen -= optlen;
	392	ip->ip_hl = hlen >> 2;
	393	ip->ip_len -= optlen;
	394	m->m_len -= optlen;
	395	}
	396
	397	ip->ip_ttl = MAXTTL;
	398	{ /* swap */
	399	struct in_addr icmp_dst;
	400	icmp_dst = ip->ip_dst;
	401	ip->ip_dst = ip->ip_src;
	402	ip->ip_src = icmp_dst;
	403	}
	404
	405	(void ) ip_output((struct socket *)NULL, m);
f0cbd3ec	406	}
e6d43cfb JK	407
	408	void icmp_receive(struct socket *so)
	409	{
	410	struct mbuf *m = so->so_m;
	411	struct ip ip = mtod(m, struct ip );
	412	int hlen = ip->ip_hl << 2;
	413	u_char error_code;
	414	struct icmp *icp;
	415	int id, len;
	416
	417	m->m_data += hlen;
	418	m->m_len -= hlen;
	419	icp = mtod(m, struct icmp *);
	420
	421	id = icp->icmp_id;
00aa0040	422	len = qemu_recv(so->s, icp, m->m_len, 0);
e6d43cfb JK	423	icp->icmp_id = id;
	424
	425	m->m_data -= hlen;
	426	m->m_len += hlen;
	427
	428	if (len == -1 \|\| len == 0) {
	429	if (errno == ENETUNREACH) {
	430	error_code = ICMP_UNREACH_NET;
	431	} else {
	432	error_code = ICMP_UNREACH_HOST;
	433	}
	434	DEBUG_MISC((dfd, " udp icmp rx errno = %d-%s\n", errno,
	435	strerror(errno)));
	436	icmp_error(so->so_m, ICMP_UNREACH, error_code, 0, strerror(errno));
	437	} else {
	438	icmp_reflect(so->so_m);
	439	so->so_m = NULL; /* Don't m_free() it again! */
	440	}
	441	icmp_detach(so);
	442	}