File:  [Qemu by Fabrice Bellard] / qemu / slirp / ip_input.c
Revision 1.1.1.11 (vendor branch): download - view: text, annotated - select for diffs
Tue Apr 24 19:51:46 2018 UTC (3 years, 4 months ago) by root
Branches: qemu, MAIN
CVS tags: qemu1101, HEAD
qemu 1.1.1

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

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