| /* | |
| * 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_input.c 8.2 (Berkeley) 1/4/94 | |
| * ip_input.c,v 1.11 1994/11/16 10:17:08 jkh Exp | |
| */ | |
| /* | |
| * Changes and additions relating to SLiRP are | |
| * Copyright (c) 1995 Danny Gasparovski. | |
| * | |
| * Please read the file COPYRIGHT for the | |
| * terms and conditions of the copyright. | |
| */ | |
| #include <slirp.h> | |
| #include <qemu/osdep.h> | |
| #include "ip_icmp.h" | |
| static struct ip *ip_reass(Slirp *slirp, struct ip *ip, struct ipq *fp); | |
| static void ip_freef(Slirp *slirp, struct ipq *fp); | |
| static void ip_enq(register struct ipasfrag *p, | |
| register struct ipasfrag *prev); | |
| static void ip_deq(register struct ipasfrag *p); | |
| /* | |
| * IP initialization: fill in IP protocol switch table. | |
| * All protocols not implemented in kernel go to raw IP protocol handler. | |
| */ | |
| void | |
| ip_init(Slirp *slirp) | |
| { | |
| slirp->ipq.ip_link.next = slirp->ipq.ip_link.prev = &slirp->ipq.ip_link; | |
| udp_init(slirp); | |
| tcp_init(slirp); | |
| icmp_init(slirp); | |
| } | |
| void ip_cleanup(Slirp *slirp) | |
| { | |
| udp_cleanup(slirp); | |
| tcp_cleanup(slirp); | |
| icmp_cleanup(slirp); | |
| } | |
| /* | |
| * Ip input routine. Checksum and byte swap header. If fragmented | |
| * try to reassemble. Process options. Pass to next level. | |
| */ | |
| void | |
| ip_input(struct mbuf *m) | |
| { | |
| Slirp *slirp = m->slirp; | |
| register struct ip *ip; | |
| int hlen; | |
| DEBUG_CALL("ip_input"); | |
| DEBUG_ARG("m = %lx", (long)m); | |
| DEBUG_ARG("m_len = %d", m->m_len); | |
| if (m->m_len < sizeof (struct ip)) { | |
| return; | |
| } | |
| ip = mtod(m, struct ip *); | |
| if (ip->ip_v != IPVERSION) { | |
| goto bad; | |
| } | |
| hlen = ip->ip_hl << 2; | |
| if (hlen<sizeof(struct ip ) || hlen>m->m_len) {/* min header length */ | |
| goto bad; /* or packet too short */ | |
| } | |
| /* keep ip header intact for ICMP reply | |
| * ip->ip_sum = cksum(m, hlen); | |
| * if (ip->ip_sum) { | |
| */ | |
| if(cksum(m,hlen)) { | |
| goto bad; | |
| } | |
| /* | |
| * Convert fields to host representation. | |
| */ | |
| NTOHS(ip->ip_len); | |
| if (ip->ip_len < hlen) { | |
| goto bad; | |
| } | |
| NTOHS(ip->ip_id); | |
| NTOHS(ip->ip_off); | |
| /* | |
| * Check that the amount of data in the buffers | |
| * is as at least much as the IP header would have us expect. | |
| * Trim mbufs if longer than we expect. | |
| * Drop packet if shorter than we expect. | |
| */ | |
| if (m->m_len < ip->ip_len) { | |
| goto bad; | |
| } | |
| /* Should drop packet if mbuf too long? hmmm... */ | |
| if (m->m_len > ip->ip_len) | |
| m_adj(m, ip->ip_len - m->m_len); | |
| /* check ip_ttl for a correct ICMP reply */ | |
| if(ip->ip_ttl==0) { | |
| icmp_error(m, ICMP_TIMXCEED,ICMP_TIMXCEED_INTRANS, 0,"ttl"); | |
| goto bad; | |
| } | |
| /* | |
| * If offset or IP_MF are set, must reassemble. | |
| * Otherwise, nothing need be done. | |
| * (We could look in the reassembly queue to see | |
| * if the packet was previously fragmented, | |
| * but it's not worth the time; just let them time out.) | |
| * | |
| * XXX This should fail, don't fragment yet | |
| */ | |
| if (ip->ip_off &~ IP_DF) { | |
| register struct ipq *fp; | |
| struct qlink *l; | |
| /* | |
| * Look for queue of fragments | |
| * of this datagram. | |
| */ | |
| for (l = (struct qlink *)slirp->ipq.ip_link.next; l != &slirp->ipq.ip_link; | |
| l = (struct qlink *)l->next) { | |
| fp = container_of(l, struct ipq, ip_link); | |
| if (ip->ip_id == fp->ipq_id && | |
| ip->ip_src.s_addr == fp->ipq_src.s_addr && | |
| ip->ip_dst.s_addr == fp->ipq_dst.s_addr && | |
| ip->ip_p == fp->ipq_p) | |
| goto found; | |
| } | |
| fp = NULL; | |
| found: | |
| /* | |
| * Adjust ip_len to not reflect header, | |
| * set ip_mff if more fragments are expected, | |
| * convert offset of this to bytes. | |
| */ | |
| ip->ip_len -= hlen; | |
| if (ip->ip_off & IP_MF) | |
| ip->ip_tos |= 1; | |
| else | |
| ip->ip_tos &= ~1; | |
| ip->ip_off <<= 3; | |
| /* | |
| * If datagram marked as having more fragments | |
| * or if this is not the first fragment, | |
| * attempt reassembly; if it succeeds, proceed. | |
| */ | |
| if (ip->ip_tos & 1 || ip->ip_off) { | |
| ip = ip_reass(slirp, ip, fp); | |
| if (ip == NULL) | |
| return; | |
| m = dtom(slirp, ip); | |
| } else | |
| if (fp) | |
| ip_freef(slirp, fp); | |
| } else | |
| ip->ip_len -= hlen; | |
| /* | |
| * Switch out to protocol's input routine. | |
| */ | |
| switch (ip->ip_p) { | |
| case IPPROTO_TCP: | |
| tcp_input(m, hlen, (struct socket *)NULL); | |
| break; | |
| case IPPROTO_UDP: | |
| udp_input(m, hlen); | |
| break; | |
| case IPPROTO_ICMP: | |
| icmp_input(m, hlen); | |
| break; | |
| default: | |
| m_free(m); | |
| } | |
| return; | |
| bad: | |
| m_free(m); | |
| } | |
| #define iptofrag(P) ((struct ipasfrag *)(((char*)(P)) - sizeof(struct qlink))) | |
| #define fragtoip(P) ((struct ip*)(((char*)(P)) + sizeof(struct qlink))) | |
| /* | |
| * Take incoming datagram fragment and try to | |
| * reassemble it into whole datagram. If a chain for | |
| * reassembly of this datagram already exists, then it | |
| * is given as fp; otherwise have to make a chain. | |
| */ | |
| static struct ip * | |
| ip_reass(Slirp *slirp, struct ip *ip, struct ipq *fp) | |
| { | |
| register struct mbuf *m = dtom(slirp, ip); | |
| register struct ipasfrag *q; | |
| int hlen = ip->ip_hl << 2; | |
| int i, next; | |
| DEBUG_CALL("ip_reass"); | |
| DEBUG_ARG("ip = %lx", (long)ip); | |
| DEBUG_ARG("fp = %lx", (long)fp); | |
| DEBUG_ARG("m = %lx", (long)m); | |
| /* | |
| * Presence of header sizes in mbufs | |
| * would confuse code below. | |
| * Fragment m_data is concatenated. | |
| */ | |
| m->m_data += hlen; | |
| m->m_len -= hlen; | |
| /* | |
| * If first fragment to arrive, create a reassembly queue. | |
| */ | |
| if (fp == NULL) { | |
| struct mbuf *t = m_get(slirp); | |
| if (t == NULL) { | |
| goto dropfrag; | |
| } | |
| fp = mtod(t, struct ipq *); | |
| insque(&fp->ip_link, &slirp->ipq.ip_link); | |
| fp->ipq_ttl = IPFRAGTTL; | |
| fp->ipq_p = ip->ip_p; | |
| fp->ipq_id = ip->ip_id; | |
| fp->frag_link.next = fp->frag_link.prev = &fp->frag_link; | |
| fp->ipq_src = ip->ip_src; | |
| fp->ipq_dst = ip->ip_dst; | |
| q = (struct ipasfrag *)fp; | |
| goto insert; | |
| } | |
| /* | |
| * Find a segment which begins after this one does. | |
| */ | |
| for (q = (struct ipasfrag *)fp->frag_link.next; q != (struct ipasfrag *)&fp->frag_link; | |
| q = (struct ipasfrag *)q->ipf_next) | |
| if (q->ipf_off > ip->ip_off) | |
| break; | |
| /* | |
| * If there is a preceding segment, it may provide some of | |
| * our data already. If so, drop the data from the incoming | |
| * segment. If it provides all of our data, drop us. | |
| */ | |
| if (q->ipf_prev != &fp->frag_link) { | |
| struct ipasfrag *pq = (struct ipasfrag *)q->ipf_prev; | |
| i = pq->ipf_off + pq->ipf_len - ip->ip_off; | |
| if (i > 0) { | |
| if (i >= ip->ip_len) | |
| goto dropfrag; | |
| m_adj(dtom(slirp, ip), i); | |
| ip->ip_off += i; | |
| ip->ip_len -= i; | |
| } | |
| } | |
| /* | |
| * While we overlap succeeding segments trim them or, | |
| * if they are completely covered, dequeue them. | |
| */ | |
| while (q != (struct ipasfrag*)&fp->frag_link && | |
| ip->ip_off + ip->ip_len > q->ipf_off) { | |
| i = (ip->ip_off + ip->ip_len) - q->ipf_off; | |
| if (i < q->ipf_len) { | |
| q->ipf_len -= i; | |
| q->ipf_off += i; | |
| m_adj(dtom(slirp, q), i); | |
| break; | |
| } | |
| q = (struct ipasfrag *)q->ipf_next; | |
| m_free(dtom(slirp, q->ipf_prev)); | |
| ip_deq((struct ipasfrag*)q->ipf_prev); | |
| } | |
| insert: | |
| /* | |
| * Stick new segment in its place; | |
| * check for complete reassembly. | |
| */ | |
| ip_enq(iptofrag(ip), (struct ipasfrag*)q->ipf_prev); | |
| next = 0; | |
| for (q = (struct ipasfrag*)fp->frag_link.next; q != (struct ipasfrag*)&fp->frag_link; | |
| q = (struct ipasfrag*)q->ipf_next) { | |
| if (q->ipf_off != next) | |
| return NULL; | |
| next += q->ipf_len; | |
| } | |
| if (((struct ipasfrag *)(q->ipf_prev))->ipf_tos & 1) | |
| return NULL; | |
| /* | |
| * Reassembly is complete; concatenate fragments. | |
| */ | |
| q = (struct ipasfrag*)fp->frag_link.next; | |
| m = dtom(slirp, q); | |
| q = (struct ipasfrag *) q->ipf_next; | |
| while (q != (struct ipasfrag*)&fp->frag_link) { | |
| struct mbuf *t = dtom(slirp, q); | |
| q = (struct ipasfrag *) q->ipf_next; | |
| m_cat(m, t); | |
| } | |
| /* | |
| * Create header for new ip packet by | |
| * modifying header of first packet; | |
| * dequeue and discard fragment reassembly header. | |
| * Make header visible. | |
| */ | |
| q = (struct ipasfrag*)fp->frag_link.next; | |
| /* | |
| * If the fragments concatenated to an mbuf that's | |
| * bigger than the total size of the fragment, then and | |
| * m_ext buffer was alloced. But fp->ipq_next points to | |
| * the old buffer (in the mbuf), so we must point ip | |
| * into the new buffer. | |
| */ | |
| if (m->m_flags & M_EXT) { | |
| int delta = (char *)q - m->m_dat; | |
| q = (struct ipasfrag *)(m->m_ext + delta); | |
| } | |
| ip = fragtoip(q); | |
| ip->ip_len = next; | |
| ip->ip_tos &= ~1; | |
| ip->ip_src = fp->ipq_src; | |
| ip->ip_dst = fp->ipq_dst; | |
| remque(&fp->ip_link); | |
| (void) m_free(dtom(slirp, fp)); | |
| m->m_len += (ip->ip_hl << 2); | |
| m->m_data -= (ip->ip_hl << 2); | |
| return ip; | |
| dropfrag: | |
| m_free(m); | |
| return NULL; | |
| } | |
| /* | |
| * Free a fragment reassembly header and all | |
| * associated datagrams. | |
| */ | |
| static void | |
| ip_freef(Slirp *slirp, struct ipq *fp) | |
| { | |
| register struct ipasfrag *q, *p; | |
| for (q = (struct ipasfrag*)fp->frag_link.next; q != (struct ipasfrag*)&fp->frag_link; q = p) { | |
| p = (struct ipasfrag*)q->ipf_next; | |
| ip_deq(q); | |
| m_free(dtom(slirp, q)); | |
| } | |
| remque(&fp->ip_link); | |
| (void) m_free(dtom(slirp, fp)); | |
| } | |
| /* | |
| * Put an ip fragment on a reassembly chain. | |
| * Like insque, but pointers in middle of structure. | |
| */ | |
| static void | |
| ip_enq(register struct ipasfrag *p, register struct ipasfrag *prev) | |
| { | |
| DEBUG_CALL("ip_enq"); | |
| DEBUG_ARG("prev = %lx", (long)prev); | |
| p->ipf_prev = prev; | |
| p->ipf_next = prev->ipf_next; | |
| ((struct ipasfrag *)(prev->ipf_next))->ipf_prev = p; | |
| prev->ipf_next = p; | |
| } | |
| /* | |
| * To ip_enq as remque is to insque. | |
| */ | |
| static void | |
| ip_deq(register struct ipasfrag *p) | |
| { | |
| ((struct ipasfrag *)(p->ipf_prev))->ipf_next = p->ipf_next; | |
| ((struct ipasfrag *)(p->ipf_next))->ipf_prev = p->ipf_prev; | |
| } | |
| /* | |
| * IP timer processing; | |
| * if a timer expires on a reassembly | |
| * queue, discard it. | |
| */ | |
| void | |
| ip_slowtimo(Slirp *slirp) | |
| { | |
| struct qlink *l; | |
| DEBUG_CALL("ip_slowtimo"); | |
| l = (struct qlink*)slirp->ipq.ip_link.next; | |
| if (l == NULL) | |
| return; | |
| while (l != &slirp->ipq.ip_link) { | |
| struct ipq *fp = container_of(l, struct ipq, ip_link); | |
| l = (struct qlink*)l->next; | |
| if (--fp->ipq_ttl == 0) { | |
| ip_freef(slirp, fp); | |
| } | |
| } | |
| } | |
| /* | |
| * Do option processing on a datagram, | |
| * possibly discarding it if bad options are encountered, | |
| * or forwarding it if source-routed. | |
| * Returns 1 if packet has been forwarded/freed, | |
| * 0 if the packet should be processed further. | |
| */ | |
| #ifdef notdef | |
| int | |
| ip_dooptions(m) | |
| struct mbuf *m; | |
| { | |
| register struct ip *ip = mtod(m, struct ip *); | |
| register u_char *cp; | |
| register struct ip_timestamp *ipt; | |
| register struct in_ifaddr *ia; | |
| int opt, optlen, cnt, off, code, type, forward = 0; | |
| struct in_addr *sin, dst; | |
| typedef uint32_t n_time; | |
| n_time ntime; | |
| dst = ip->ip_dst; | |
| cp = (u_char *)(ip + 1); | |
| cnt = (ip->ip_hl << 2) - sizeof (struct ip); | |
| for (; cnt > 0; cnt -= optlen, cp += optlen) { | |
| opt = cp[IPOPT_OPTVAL]; | |
| if (opt == IPOPT_EOL) | |
| break; | |
| if (opt == IPOPT_NOP) | |
| optlen = 1; | |
| else { | |
| optlen = cp[IPOPT_OLEN]; | |
| if (optlen <= 0 || optlen > cnt) { | |
| code = &cp[IPOPT_OLEN] - (u_char *)ip; | |
| goto bad; | |
| } | |
| } | |
| switch (opt) { | |
| default: | |
| break; | |
| /* | |
| * Source routing with record. | |
| * Find interface with current destination address. | |
| * If none on this machine then drop if strictly routed, | |
| * or do nothing if loosely routed. | |
| * Record interface address and bring up next address | |
| * component. If strictly routed make sure next | |
| * address is on directly accessible net. | |
| */ | |
| case IPOPT_LSRR: | |
| case IPOPT_SSRR: | |
| if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { | |
| code = &cp[IPOPT_OFFSET] - (u_char *)ip; | |
| goto bad; | |
| } | |
| ipaddr.sin_addr = ip->ip_dst; | |
| ia = (struct in_ifaddr *) | |
| ifa_ifwithaddr((struct sockaddr *)&ipaddr); | |
| if (ia == 0) { | |
| if (opt == IPOPT_SSRR) { | |
| type = ICMP_UNREACH; | |
| code = ICMP_UNREACH_SRCFAIL; | |
| goto bad; | |
| } | |
| /* | |
| * Loose routing, and not at next destination | |
| * yet; nothing to do except forward. | |
| */ | |
| break; | |
| } | |
| off--; /* 0 origin */ | |
| if (off > optlen - sizeof(struct in_addr)) { | |
| /* | |
| * End of source route. Should be for us. | |
| */ | |
| save_rte(cp, ip->ip_src); | |
| break; | |
| } | |
| /* | |
| * locate outgoing interface | |
| */ | |
| bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr, | |
| sizeof(ipaddr.sin_addr)); | |
| if (opt == IPOPT_SSRR) { | |
| #define INA struct in_ifaddr * | |
| #define SA struct sockaddr * | |
| if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0) | |
| ia = (INA)ifa_ifwithnet((SA)&ipaddr); | |
| } else | |
| ia = ip_rtaddr(ipaddr.sin_addr); | |
| if (ia == 0) { | |
| type = ICMP_UNREACH; | |
| code = ICMP_UNREACH_SRCFAIL; | |
| goto bad; | |
| } | |
| ip->ip_dst = ipaddr.sin_addr; | |
| bcopy((caddr_t)&(IA_SIN(ia)->sin_addr), | |
| (caddr_t)(cp + off), sizeof(struct in_addr)); | |
| cp[IPOPT_OFFSET] += sizeof(struct in_addr); | |
| /* | |
| * Let ip_intr's mcast routing check handle mcast pkts | |
| */ | |
| forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr)); | |
| break; | |
| case IPOPT_RR: | |
| if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { | |
| code = &cp[IPOPT_OFFSET] - (u_char *)ip; | |
| goto bad; | |
| } | |
| /* | |
| * If no space remains, ignore. | |
| */ | |
| off--; /* 0 origin */ | |
| if (off > optlen - sizeof(struct in_addr)) | |
| break; | |
| bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr, | |
| sizeof(ipaddr.sin_addr)); | |
| /* | |
| * locate outgoing interface; if we're the destination, | |
| * use the incoming interface (should be same). | |
| */ | |
| if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 && | |
| (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) { | |
| type = ICMP_UNREACH; | |
| code = ICMP_UNREACH_HOST; | |
| goto bad; | |
| } | |
| bcopy((caddr_t)&(IA_SIN(ia)->sin_addr), | |
| (caddr_t)(cp + off), sizeof(struct in_addr)); | |
| cp[IPOPT_OFFSET] += sizeof(struct in_addr); | |
| break; | |
| case IPOPT_TS: | |
| code = cp - (u_char *)ip; | |
| ipt = (struct ip_timestamp *)cp; | |
| if (ipt->ipt_len < 5) | |
| goto bad; | |
| if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) { | |
| if (++ipt->ipt_oflw == 0) | |
| goto bad; | |
| break; | |
| } | |
| sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1); | |
| switch (ipt->ipt_flg) { | |
| case IPOPT_TS_TSONLY: | |
| break; | |
| case IPOPT_TS_TSANDADDR: | |
| if (ipt->ipt_ptr + sizeof(n_time) + | |
| sizeof(struct in_addr) > ipt->ipt_len) | |
| goto bad; | |
| ipaddr.sin_addr = dst; | |
| ia = (INA)ifaof_ i f p foraddr((SA)&ipaddr, | |
| m->m_pkthdr.rcvif); | |
| if (ia == 0) | |
| continue; | |
| bcopy((caddr_t)&IA_SIN(ia)->sin_addr, | |
| (caddr_t)sin, sizeof(struct in_addr)); | |
| ipt->ipt_ptr += sizeof(struct in_addr); | |
| break; | |
| case IPOPT_TS_PRESPEC: | |
| if (ipt->ipt_ptr + sizeof(n_time) + | |
| sizeof(struct in_addr) > ipt->ipt_len) | |
| goto bad; | |
| bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr, | |
| sizeof(struct in_addr)); | |
| if (ifa_ifwithaddr((SA)&ipaddr) == 0) | |
| continue; | |
| ipt->ipt_ptr += sizeof(struct in_addr); | |
| break; | |
| default: | |
| goto bad; | |
| } | |
| ntime = iptime(); | |
| bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1, | |
| sizeof(n_time)); | |
| ipt->ipt_ptr += sizeof(n_time); | |
| } | |
| } | |
| if (forward) { | |
| ip_forward(m, 1); | |
| return (1); | |
| } | |
| return (0); | |
| bad: | |
| icmp_error(m, type, code, 0, 0); | |
| return (1); | |
| } | |
| #endif /* notdef */ | |
| /* | |
| * Strip out IP options, at higher | |
| * level protocol in the kernel. | |
| * Second argument is buffer to which options | |
| * will be moved, and return value is their length. | |
| * (XXX) should be deleted; last arg currently ignored. | |
| */ | |
| void | |
| ip_stripoptions(register struct mbuf *m, struct mbuf *mopt) | |
| { | |
| register int i; | |
| struct ip *ip = mtod(m, struct ip *); | |
| register caddr_t opts; | |
| int olen; | |
| olen = (ip->ip_hl<<2) - sizeof (struct ip); | |
| opts = (caddr_t)(ip + 1); | |
| i = m->m_len - (sizeof (struct ip) + olen); | |
| memcpy(opts, opts + olen, (unsigned)i); | |
| m->m_len -= olen; | |
| ip->ip_hl = sizeof(struct ip) >> 2; | |
| } |