File:  [Qemu by Fabrice Bellard] / qemu / slirp / ip_input.c
Revision 1.1.1.6 (vendor branch): download - view: text, annotated - select for diffs
Tue Apr 24 17:41:15 2018 UTC (2 years, 11 months ago) by root
Branches: qemu, MAIN
CVS tags: qemu0125, qemu0124, qemu0123, qemu0122, qemu0121, qemu0120, HEAD
qemu 0.12.0

    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.
   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.
   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_input.c	8.2 (Berkeley) 1/4/94
   30:  * ip_input.c,v 1.11 1994/11/16 10:17:08 jkh Exp
   31:  */
   32: 
   33: /*
   34:  * Changes and additions relating to SLiRP are
   35:  * Copyright (c) 1995 Danny Gasparovski.
   36:  *
   37:  * Please read the file COPYRIGHT for the
   38:  * terms and conditions of the copyright.
   39:  */
   40: 
   41: #include <slirp.h>
   42: #include <osdep.h>
   43: #include "ip_icmp.h"
   44: 
   45: static struct ip *ip_reass(Slirp *slirp, struct ip *ip, struct ipq *fp);
   46: static void ip_freef(Slirp *slirp, struct ipq *fp);
   47: static void ip_enq(register struct ipasfrag *p,
   48:                    register struct ipasfrag *prev);
   49: static void ip_deq(register struct ipasfrag *p);
   50: 
   51: /*
   52:  * IP initialization: fill in IP protocol switch table.
   53:  * All protocols not implemented in kernel go to raw IP protocol handler.
   54:  */
   55: void
   56: ip_init(Slirp *slirp)
   57: {
   58:     slirp->ipq.ip_link.next = slirp->ipq.ip_link.prev = &slirp->ipq.ip_link;
   59:     udp_init(slirp);
   60:     tcp_init(slirp);
   61: }
   62: 
   63: /*
   64:  * Ip input routine.  Checksum and byte swap header.  If fragmented
   65:  * try to reassemble.  Process options.  Pass to next level.
   66:  */
   67: void
   68: ip_input(struct mbuf *m)
   69: {
   70: 	Slirp *slirp = m->slirp;
   71: 	register struct ip *ip;
   72: 	int hlen;
   73: 
   74: 	DEBUG_CALL("ip_input");
   75: 	DEBUG_ARG("m = %lx", (long)m);
   76: 	DEBUG_ARG("m_len = %d", m->m_len);
   77: 
   78: 	if (m->m_len < sizeof (struct ip)) {
   79: 		return;
   80: 	}
   81: 
   82: 	ip = mtod(m, struct ip *);
   83: 
   84: 	if (ip->ip_v != IPVERSION) {
   85: 		goto bad;
   86: 	}
   87: 
   88: 	hlen = ip->ip_hl << 2;
   89: 	if (hlen<sizeof(struct ip ) || hlen>m->m_len) {/* min header length */
   90: 	  goto bad;                                  /* or packet too short */
   91: 	}
   92: 
   93:         /* keep ip header intact for ICMP reply
   94: 	 * ip->ip_sum = cksum(m, hlen);
   95: 	 * if (ip->ip_sum) {
   96: 	 */
   97: 	if(cksum(m,hlen)) {
   98: 	  goto bad;
   99: 	}
  100: 
  101: 	/*
  102: 	 * Convert fields to host representation.
  103: 	 */
  104: 	NTOHS(ip->ip_len);
  105: 	if (ip->ip_len < hlen) {
  106: 		goto bad;
  107: 	}
  108: 	NTOHS(ip->ip_id);
  109: 	NTOHS(ip->ip_off);
  110: 
  111: 	/*
  112: 	 * Check that the amount of data in the buffers
  113: 	 * is as at least much as the IP header would have us expect.
  114: 	 * Trim mbufs if longer than we expect.
  115: 	 * Drop packet if shorter than we expect.
  116: 	 */
  117: 	if (m->m_len < ip->ip_len) {
  118: 		goto bad;
  119: 	}
  120: 
  121:     if (slirp->restricted) {
  122:         if ((ip->ip_dst.s_addr & slirp->vnetwork_mask.s_addr) ==
  123:             slirp->vnetwork_addr.s_addr) {
  124:             if (ip->ip_dst.s_addr == 0xffffffff && ip->ip_p != IPPROTO_UDP)
  125:                 goto bad;
  126:         } else {
  127:             uint32_t inv_mask = ~slirp->vnetwork_mask.s_addr;
  128:             struct ex_list *ex_ptr;
  129: 
  130:             if ((ip->ip_dst.s_addr & inv_mask) == inv_mask) {
  131:                 goto bad;
  132:             }
  133:             for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next)
  134:                 if (ex_ptr->ex_addr.s_addr == ip->ip_dst.s_addr)
  135:                     break;
  136: 
  137:             if (!ex_ptr)
  138:                 goto bad;
  139:         }
  140:     }
  141: 
  142: 	/* Should drop packet if mbuf too long? hmmm... */
  143: 	if (m->m_len > ip->ip_len)
  144: 	   m_adj(m, ip->ip_len - m->m_len);
  145: 
  146: 	/* check ip_ttl for a correct ICMP reply */
  147: 	if(ip->ip_ttl==0 || ip->ip_ttl==1) {
  148: 	  icmp_error(m, ICMP_TIMXCEED,ICMP_TIMXCEED_INTRANS, 0,"ttl");
  149: 	  goto bad;
  150: 	}
  151: 
  152: 	/*
  153: 	 * If offset or IP_MF are set, must reassemble.
  154: 	 * Otherwise, nothing need be done.
  155: 	 * (We could look in the reassembly queue to see
  156: 	 * if the packet was previously fragmented,
  157: 	 * but it's not worth the time; just let them time out.)
  158: 	 *
  159: 	 * XXX This should fail, don't fragment yet
  160: 	 */
  161: 	if (ip->ip_off &~ IP_DF) {
  162: 	  register struct ipq *fp;
  163:       struct qlink *l;
  164: 		/*
  165: 		 * Look for queue of fragments
  166: 		 * of this datagram.
  167: 		 */
  168: 		for (l = slirp->ipq.ip_link.next; l != &slirp->ipq.ip_link;
  169: 		     l = l->next) {
  170:             fp = container_of(l, struct ipq, ip_link);
  171:             if (ip->ip_id == fp->ipq_id &&
  172:                     ip->ip_src.s_addr == fp->ipq_src.s_addr &&
  173:                     ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
  174:                     ip->ip_p == fp->ipq_p)
  175: 		    goto found;
  176:         }
  177:         fp = NULL;
  178: 	found:
  179: 
  180: 		/*
  181: 		 * Adjust ip_len to not reflect header,
  182: 		 * set ip_mff if more fragments are expected,
  183: 		 * convert offset of this to bytes.
  184: 		 */
  185: 		ip->ip_len -= hlen;
  186: 		if (ip->ip_off & IP_MF)
  187: 		  ip->ip_tos |= 1;
  188: 		else
  189: 		  ip->ip_tos &= ~1;
  190: 
  191: 		ip->ip_off <<= 3;
  192: 
  193: 		/*
  194: 		 * If datagram marked as having more fragments
  195: 		 * or if this is not the first fragment,
  196: 		 * attempt reassembly; if it succeeds, proceed.
  197: 		 */
  198: 		if (ip->ip_tos & 1 || ip->ip_off) {
  199: 			ip = ip_reass(slirp, ip, fp);
  200:                         if (ip == NULL)
  201: 				return;
  202: 			m = dtom(slirp, ip);
  203: 		} else
  204: 			if (fp)
  205: 		   	   ip_freef(slirp, fp);
  206: 
  207: 	} else
  208: 		ip->ip_len -= hlen;
  209: 
  210: 	/*
  211: 	 * Switch out to protocol's input routine.
  212: 	 */
  213: 	switch (ip->ip_p) {
  214: 	 case IPPROTO_TCP:
  215: 		tcp_input(m, hlen, (struct socket *)NULL);
  216: 		break;
  217: 	 case IPPROTO_UDP:
  218: 		udp_input(m, hlen);
  219: 		break;
  220: 	 case IPPROTO_ICMP:
  221: 		icmp_input(m, hlen);
  222: 		break;
  223: 	 default:
  224: 		m_free(m);
  225: 	}
  226: 	return;
  227: bad:
  228: 	m_freem(m);
  229: 	return;
  230: }
  231: 
  232: #define iptofrag(P) ((struct ipasfrag *)(((char*)(P)) - sizeof(struct qlink)))
  233: #define fragtoip(P) ((struct ip*)(((char*)(P)) + sizeof(struct qlink)))
  234: /*
  235:  * Take incoming datagram fragment and try to
  236:  * reassemble it into whole datagram.  If a chain for
  237:  * reassembly of this datagram already exists, then it
  238:  * is given as fp; otherwise have to make a chain.
  239:  */
  240: static struct ip *
  241: ip_reass(Slirp *slirp, struct ip *ip, struct ipq *fp)
  242: {
  243: 	register struct mbuf *m = dtom(slirp, ip);
  244: 	register struct ipasfrag *q;
  245: 	int hlen = ip->ip_hl << 2;
  246: 	int i, next;
  247: 
  248: 	DEBUG_CALL("ip_reass");
  249: 	DEBUG_ARG("ip = %lx", (long)ip);
  250: 	DEBUG_ARG("fp = %lx", (long)fp);
  251: 	DEBUG_ARG("m = %lx", (long)m);
  252: 
  253: 	/*
  254: 	 * Presence of header sizes in mbufs
  255: 	 * would confuse code below.
  256:          * Fragment m_data is concatenated.
  257: 	 */
  258: 	m->m_data += hlen;
  259: 	m->m_len -= hlen;
  260: 
  261: 	/*
  262: 	 * If first fragment to arrive, create a reassembly queue.
  263: 	 */
  264:         if (fp == NULL) {
  265: 	  struct mbuf *t = m_get(slirp);
  266: 
  267: 	  if (t == NULL) {
  268: 	      goto dropfrag;
  269: 	  }
  270: 	  fp = mtod(t, struct ipq *);
  271: 	  insque(&fp->ip_link, &slirp->ipq.ip_link);
  272: 	  fp->ipq_ttl = IPFRAGTTL;
  273: 	  fp->ipq_p = ip->ip_p;
  274: 	  fp->ipq_id = ip->ip_id;
  275: 	  fp->frag_link.next = fp->frag_link.prev = &fp->frag_link;
  276: 	  fp->ipq_src = ip->ip_src;
  277: 	  fp->ipq_dst = ip->ip_dst;
  278: 	  q = (struct ipasfrag *)fp;
  279: 	  goto insert;
  280: 	}
  281: 
  282: 	/*
  283: 	 * Find a segment which begins after this one does.
  284: 	 */
  285: 	for (q = fp->frag_link.next; q != (struct ipasfrag *)&fp->frag_link;
  286:             q = q->ipf_next)
  287: 		if (q->ipf_off > ip->ip_off)
  288: 			break;
  289: 
  290: 	/*
  291: 	 * If there is a preceding segment, it may provide some of
  292: 	 * our data already.  If so, drop the data from the incoming
  293: 	 * segment.  If it provides all of our data, drop us.
  294: 	 */
  295: 	if (q->ipf_prev != &fp->frag_link) {
  296:         struct ipasfrag *pq = q->ipf_prev;
  297: 		i = pq->ipf_off + pq->ipf_len - ip->ip_off;
  298: 		if (i > 0) {
  299: 			if (i >= ip->ip_len)
  300: 				goto dropfrag;
  301: 			m_adj(dtom(slirp, ip), i);
  302: 			ip->ip_off += i;
  303: 			ip->ip_len -= i;
  304: 		}
  305: 	}
  306: 
  307: 	/*
  308: 	 * While we overlap succeeding segments trim them or,
  309: 	 * if they are completely covered, dequeue them.
  310: 	 */
  311: 	while (q != (struct ipasfrag*)&fp->frag_link &&
  312:             ip->ip_off + ip->ip_len > q->ipf_off) {
  313: 		i = (ip->ip_off + ip->ip_len) - q->ipf_off;
  314: 		if (i < q->ipf_len) {
  315: 			q->ipf_len -= i;
  316: 			q->ipf_off += i;
  317: 			m_adj(dtom(slirp, q), i);
  318: 			break;
  319: 		}
  320: 		q = q->ipf_next;
  321: 		m_freem(dtom(slirp, q->ipf_prev));
  322: 		ip_deq(q->ipf_prev);
  323: 	}
  324: 
  325: insert:
  326: 	/*
  327: 	 * Stick new segment in its place;
  328: 	 * check for complete reassembly.
  329: 	 */
  330: 	ip_enq(iptofrag(ip), q->ipf_prev);
  331: 	next = 0;
  332: 	for (q = fp->frag_link.next; q != (struct ipasfrag*)&fp->frag_link;
  333:             q = q->ipf_next) {
  334: 		if (q->ipf_off != next)
  335:                         return NULL;
  336: 		next += q->ipf_len;
  337: 	}
  338: 	if (((struct ipasfrag *)(q->ipf_prev))->ipf_tos & 1)
  339:                 return NULL;
  340: 
  341: 	/*
  342: 	 * Reassembly is complete; concatenate fragments.
  343: 	 */
  344:     q = fp->frag_link.next;
  345: 	m = dtom(slirp, q);
  346: 
  347: 	q = (struct ipasfrag *) q->ipf_next;
  348: 	while (q != (struct ipasfrag*)&fp->frag_link) {
  349: 	  struct mbuf *t = dtom(slirp, q);
  350: 	  q = (struct ipasfrag *) q->ipf_next;
  351: 	  m_cat(m, t);
  352: 	}
  353: 
  354: 	/*
  355: 	 * Create header for new ip packet by
  356: 	 * modifying header of first packet;
  357: 	 * dequeue and discard fragment reassembly header.
  358: 	 * Make header visible.
  359: 	 */
  360: 	q = fp->frag_link.next;
  361: 
  362: 	/*
  363: 	 * If the fragments concatenated to an mbuf that's
  364: 	 * bigger than the total size of the fragment, then and
  365: 	 * m_ext buffer was alloced. But fp->ipq_next points to
  366: 	 * the old buffer (in the mbuf), so we must point ip
  367: 	 * into the new buffer.
  368: 	 */
  369: 	if (m->m_flags & M_EXT) {
  370: 	  int delta = (char *)q - m->m_dat;
  371: 	  q = (struct ipasfrag *)(m->m_ext + delta);
  372: 	}
  373: 
  374:     ip = fragtoip(q);
  375: 	ip->ip_len = next;
  376: 	ip->ip_tos &= ~1;
  377: 	ip->ip_src = fp->ipq_src;
  378: 	ip->ip_dst = fp->ipq_dst;
  379: 	remque(&fp->ip_link);
  380: 	(void) m_free(dtom(slirp, fp));
  381: 	m->m_len += (ip->ip_hl << 2);
  382: 	m->m_data -= (ip->ip_hl << 2);
  383: 
  384: 	return ip;
  385: 
  386: dropfrag:
  387: 	m_freem(m);
  388:         return NULL;
  389: }
  390: 
  391: /*
  392:  * Free a fragment reassembly header and all
  393:  * associated datagrams.
  394:  */
  395: static void
  396: ip_freef(Slirp *slirp, struct ipq *fp)
  397: {
  398: 	register struct ipasfrag *q, *p;
  399: 
  400: 	for (q = fp->frag_link.next; q != (struct ipasfrag*)&fp->frag_link; q = p) {
  401: 		p = q->ipf_next;
  402: 		ip_deq(q);
  403: 		m_freem(dtom(slirp, q));
  404: 	}
  405: 	remque(&fp->ip_link);
  406: 	(void) m_free(dtom(slirp, fp));
  407: }
  408: 
  409: /*
  410:  * Put an ip fragment on a reassembly chain.
  411:  * Like insque, but pointers in middle of structure.
  412:  */
  413: static void
  414: ip_enq(register struct ipasfrag *p, register struct ipasfrag *prev)
  415: {
  416: 	DEBUG_CALL("ip_enq");
  417: 	DEBUG_ARG("prev = %lx", (long)prev);
  418: 	p->ipf_prev =  prev;
  419: 	p->ipf_next = prev->ipf_next;
  420: 	((struct ipasfrag *)(prev->ipf_next))->ipf_prev = p;
  421: 	prev->ipf_next = p;
  422: }
  423: 
  424: /*
  425:  * To ip_enq as remque is to insque.
  426:  */
  427: static void
  428: ip_deq(register struct ipasfrag *p)
  429: {
  430: 	((struct ipasfrag *)(p->ipf_prev))->ipf_next = p->ipf_next;
  431: 	((struct ipasfrag *)(p->ipf_next))->ipf_prev = p->ipf_prev;
  432: }
  433: 
  434: /*
  435:  * IP timer processing;
  436:  * if a timer expires on a reassembly
  437:  * queue, discard it.
  438:  */
  439: void
  440: ip_slowtimo(Slirp *slirp)
  441: {
  442:     struct qlink *l;
  443: 
  444: 	DEBUG_CALL("ip_slowtimo");
  445: 
  446:     l = slirp->ipq.ip_link.next;
  447: 
  448:         if (l == NULL)
  449: 	   return;
  450: 
  451:     while (l != &slirp->ipq.ip_link) {
  452:         struct ipq *fp = container_of(l, struct ipq, ip_link);
  453:         l = l->next;
  454: 		if (--fp->ipq_ttl == 0) {
  455: 			ip_freef(slirp, fp);
  456: 		}
  457:     }
  458: }
  459: 
  460: /*
  461:  * Do option processing on a datagram,
  462:  * possibly discarding it if bad options are encountered,
  463:  * or forwarding it if source-routed.
  464:  * Returns 1 if packet has been forwarded/freed,
  465:  * 0 if the packet should be processed further.
  466:  */
  467: 
  468: #ifdef notdef
  469: 
  470: int
  471: ip_dooptions(m)
  472: 	struct mbuf *m;
  473: {
  474: 	register struct ip *ip = mtod(m, struct ip *);
  475: 	register u_char *cp;
  476: 	register struct ip_timestamp *ipt;
  477: 	register struct in_ifaddr *ia;
  478: 	int opt, optlen, cnt, off, code, type, forward = 0;
  479: 	struct in_addr *sin, dst;
  480: typedef u_int32_t n_time;
  481: 	n_time ntime;
  482: 
  483: 	dst = ip->ip_dst;
  484: 	cp = (u_char *)(ip + 1);
  485: 	cnt = (ip->ip_hl << 2) - sizeof (struct ip);
  486: 	for (; cnt > 0; cnt -= optlen, cp += optlen) {
  487: 		opt = cp[IPOPT_OPTVAL];
  488: 		if (opt == IPOPT_EOL)
  489: 			break;
  490: 		if (opt == IPOPT_NOP)
  491: 			optlen = 1;
  492: 		else {
  493: 			optlen = cp[IPOPT_OLEN];
  494: 			if (optlen <= 0 || optlen > cnt) {
  495: 				code = &cp[IPOPT_OLEN] - (u_char *)ip;
  496: 				goto bad;
  497: 			}
  498: 		}
  499: 		switch (opt) {
  500: 
  501: 		default:
  502: 			break;
  503: 
  504: 		/*
  505: 		 * Source routing with record.
  506: 		 * Find interface with current destination address.
  507: 		 * If none on this machine then drop if strictly routed,
  508: 		 * or do nothing if loosely routed.
  509: 		 * Record interface address and bring up next address
  510: 		 * component.  If strictly routed make sure next
  511: 		 * address is on directly accessible net.
  512: 		 */
  513: 		case IPOPT_LSRR:
  514: 		case IPOPT_SSRR:
  515: 			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
  516: 				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
  517: 				goto bad;
  518: 			}
  519: 			ipaddr.sin_addr = ip->ip_dst;
  520: 			ia = (struct in_ifaddr *)
  521: 				ifa_ifwithaddr((struct sockaddr *)&ipaddr);
  522: 			if (ia == 0) {
  523: 				if (opt == IPOPT_SSRR) {
  524: 					type = ICMP_UNREACH;
  525: 					code = ICMP_UNREACH_SRCFAIL;
  526: 					goto bad;
  527: 				}
  528: 				/*
  529: 				 * Loose routing, and not at next destination
  530: 				 * yet; nothing to do except forward.
  531: 				 */
  532: 				break;
  533: 			}
  534: 			off--;			/ * 0 origin *  /
  535: 			if (off > optlen - sizeof(struct in_addr)) {
  536: 				/*
  537: 				 * End of source route.  Should be for us.
  538: 				 */
  539: 				save_rte(cp, ip->ip_src);
  540: 				break;
  541: 			}
  542: 			/*
  543: 			 * locate outgoing interface
  544: 			 */
  545: 			bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
  546: 			    sizeof(ipaddr.sin_addr));
  547: 			if (opt == IPOPT_SSRR) {
  548: #define	INA	struct in_ifaddr *
  549: #define	SA	struct sockaddr *
  550:  			    if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
  551: 				ia = (INA)ifa_ifwithnet((SA)&ipaddr);
  552: 			} else
  553: 				ia = ip_rtaddr(ipaddr.sin_addr);
  554: 			if (ia == 0) {
  555: 				type = ICMP_UNREACH;
  556: 				code = ICMP_UNREACH_SRCFAIL;
  557: 				goto bad;
  558: 			}
  559: 			ip->ip_dst = ipaddr.sin_addr;
  560: 			bcopy((caddr_t)&(IA_SIN(ia)->sin_addr),
  561: 			    (caddr_t)(cp + off), sizeof(struct in_addr));
  562: 			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
  563: 			/*
  564: 			 * Let ip_intr's mcast routing check handle mcast pkts
  565: 			 */
  566: 			forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
  567: 			break;
  568: 
  569: 		case IPOPT_RR:
  570: 			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
  571: 				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
  572: 				goto bad;
  573: 			}
  574: 			/*
  575: 			 * If no space remains, ignore.
  576: 			 */
  577: 			off--;			 * 0 origin *
  578: 			if (off > optlen - sizeof(struct in_addr))
  579: 				break;
  580: 			bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
  581: 			    sizeof(ipaddr.sin_addr));
  582: 			/*
  583: 			 * locate outgoing interface; if we're the destination,
  584: 			 * use the incoming interface (should be same).
  585: 			 */
  586: 			if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
  587: 			    (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
  588: 				type = ICMP_UNREACH;
  589: 				code = ICMP_UNREACH_HOST;
  590: 				goto bad;
  591: 			}
  592: 			bcopy((caddr_t)&(IA_SIN(ia)->sin_addr),
  593: 			    (caddr_t)(cp + off), sizeof(struct in_addr));
  594: 			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
  595: 			break;
  596: 
  597: 		case IPOPT_TS:
  598: 			code = cp - (u_char *)ip;
  599: 			ipt = (struct ip_timestamp *)cp;
  600: 			if (ipt->ipt_len < 5)
  601: 				goto bad;
  602: 			if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
  603: 				if (++ipt->ipt_oflw == 0)
  604: 					goto bad;
  605: 				break;
  606: 			}
  607: 			sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
  608: 			switch (ipt->ipt_flg) {
  609: 
  610: 			case IPOPT_TS_TSONLY:
  611: 				break;
  612: 
  613: 			case IPOPT_TS_TSANDADDR:
  614: 				if (ipt->ipt_ptr + sizeof(n_time) +
  615: 				    sizeof(struct in_addr) > ipt->ipt_len)
  616: 					goto bad;
  617: 				ipaddr.sin_addr = dst;
  618: 				ia = (INA)ifaof_ i f p foraddr((SA)&ipaddr,
  619: 							    m->m_pkthdr.rcvif);
  620: 				if (ia == 0)
  621: 					continue;
  622: 				bcopy((caddr_t)&IA_SIN(ia)->sin_addr,
  623: 				    (caddr_t)sin, sizeof(struct in_addr));
  624: 				ipt->ipt_ptr += sizeof(struct in_addr);
  625: 				break;
  626: 
  627: 			case IPOPT_TS_PRESPEC:
  628: 				if (ipt->ipt_ptr + sizeof(n_time) +
  629: 				    sizeof(struct in_addr) > ipt->ipt_len)
  630: 					goto bad;
  631: 				bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
  632: 				    sizeof(struct in_addr));
  633: 				if (ifa_ifwithaddr((SA)&ipaddr) == 0)
  634: 					continue;
  635: 				ipt->ipt_ptr += sizeof(struct in_addr);
  636: 				break;
  637: 
  638: 			default:
  639: 				goto bad;
  640: 			}
  641: 			ntime = iptime();
  642: 			bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
  643: 			    sizeof(n_time));
  644: 			ipt->ipt_ptr += sizeof(n_time);
  645: 		}
  646: 	}
  647: 	if (forward) {
  648: 		ip_forward(m, 1);
  649: 		return (1);
  650: 	}
  651: 	return (0);
  652: bad:
  653:  	icmp_error(m, type, code, 0, 0);
  654: 
  655: 	return (1);
  656: }
  657: 
  658: #endif /* notdef */
  659: 
  660: /*
  661:  * Strip out IP options, at higher
  662:  * level protocol in the kernel.
  663:  * Second argument is buffer to which options
  664:  * will be moved, and return value is their length.
  665:  * (XXX) should be deleted; last arg currently ignored.
  666:  */
  667: void
  668: ip_stripoptions(register struct mbuf *m, struct mbuf *mopt)
  669: {
  670: 	register int i;
  671: 	struct ip *ip = mtod(m, struct ip *);
  672: 	register caddr_t opts;
  673: 	int olen;
  674: 
  675: 	olen = (ip->ip_hl<<2) - sizeof (struct ip);
  676: 	opts = (caddr_t)(ip + 1);
  677: 	i = m->m_len - (sizeof (struct ip) + olen);
  678: 	memcpy(opts, opts  + olen, (unsigned)i);
  679: 	m->m_len -= olen;
  680: 
  681: 	ip->ip_hl = sizeof(struct ip) >> 2;
  682: }

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