ip_options.c revision 175630
1152592Sandre/* 2152592Sandre * Copyright (c) 1982, 1986, 1988, 1993 3169464Srwatson * The Regents of the University of California. 4169464Srwatson * Copyright (c) 2005 Andre Oppermann, Internet Business Solutions AG. 5169464Srwatson * All rights reserved. 6152592Sandre * 7152592Sandre * Redistribution and use in source and binary forms, with or without 8152592Sandre * modification, are permitted provided that the following conditions 9152592Sandre * are met: 10152592Sandre * 1. Redistributions of source code must retain the above copyright 11152592Sandre * notice, this list of conditions and the following disclaimer. 12152592Sandre * 2. Redistributions in binary form must reproduce the above copyright 13152592Sandre * notice, this list of conditions and the following disclaimer in the 14152592Sandre * documentation and/or other materials provided with the distribution. 15152592Sandre * 4. Neither the name of the University nor the names of its contributors 16152592Sandre * may be used to endorse or promote products derived from this software 17152592Sandre * without specific prior written permission. 18152592Sandre * 19152592Sandre * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20152592Sandre * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21152592Sandre * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22152592Sandre * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23152592Sandre * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24152592Sandre * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25152592Sandre * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26152592Sandre * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27152592Sandre * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28152592Sandre * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29152592Sandre * SUCH DAMAGE. 30152592Sandre */ 31152592Sandre 32172467Ssilby#include <sys/cdefs.h> 33172467Ssilby__FBSDID("$FreeBSD: head/sys/netinet/ip_options.c 175630 2008-01-24 08:25:59Z bz $"); 34172467Ssilby 35152592Sandre#include "opt_ipstealth.h" 36152592Sandre#include "opt_mac.h" 37152592Sandre 38152592Sandre#include <sys/param.h> 39152592Sandre#include <sys/systm.h> 40152592Sandre#include <sys/mbuf.h> 41152592Sandre#include <sys/domain.h> 42152592Sandre#include <sys/protosw.h> 43152592Sandre#include <sys/socket.h> 44152592Sandre#include <sys/time.h> 45152592Sandre#include <sys/kernel.h> 46152592Sandre#include <sys/syslog.h> 47152592Sandre#include <sys/sysctl.h> 48152592Sandre 49152592Sandre#include <net/if.h> 50152592Sandre#include <net/if_types.h> 51152592Sandre#include <net/if_var.h> 52152592Sandre#include <net/if_dl.h> 53152592Sandre#include <net/route.h> 54152592Sandre#include <net/netisr.h> 55152592Sandre 56152592Sandre#include <netinet/in.h> 57152592Sandre#include <netinet/in_systm.h> 58152592Sandre#include <netinet/in_var.h> 59152592Sandre#include <netinet/ip.h> 60152592Sandre#include <netinet/in_pcb.h> 61152592Sandre#include <netinet/ip_var.h> 62152592Sandre#include <netinet/ip_options.h> 63152592Sandre#include <netinet/ip_icmp.h> 64152592Sandre#include <machine/in_cksum.h> 65152592Sandre 66152592Sandre#include <sys/socketvar.h> 67152592Sandre 68163606Srwatson#include <security/mac/mac_framework.h> 69163606Srwatson 70152592Sandrestatic int ip_dosourceroute = 0; 71152592SandreSYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW, 72152592Sandre &ip_dosourceroute, 0, "Enable forwarding source routed IP packets"); 73152592Sandre 74152592Sandrestatic int ip_acceptsourceroute = 0; 75152592SandreSYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute, 76152592Sandre CTLFLAG_RW, &ip_acceptsourceroute, 0, 77152592Sandre "Enable accepting source routed IP packets"); 78152592Sandre 79152592Sandreint ip_doopts = 1; /* 0 = ignore, 1 = process, 2 = reject */ 80152592SandreSYSCTL_INT(_net_inet_ip, OID_AUTO, process_options, CTLFLAG_RW, 81152592Sandre &ip_doopts, 0, "Enable IP options processing ([LS]SRR, RR, TS)"); 82152592Sandre 83152592Sandrestatic void save_rte(struct mbuf *m, u_char *, struct in_addr); 84152592Sandre 85152592Sandre/* 86169464Srwatson * Do option processing on a datagram, possibly discarding it if bad options 87169464Srwatson * are encountered, or forwarding it if source-routed. 88169464Srwatson * 89169464Srwatson * The pass argument is used when operating in the IPSTEALTH mode to tell 90169464Srwatson * what options to process: [LS]SRR (pass 0) or the others (pass 1). The 91169464Srwatson * reason for as many as two passes is that when doing IPSTEALTH, non-routing 92169464Srwatson * options should be processed only if the packet is for us. 93169464Srwatson * 94169464Srwatson * Returns 1 if packet has been forwarded/freed, 0 if the packet should be 95169464Srwatson * processed further. 96152592Sandre */ 97152592Sandreint 98152592Sandreip_dooptions(struct mbuf *m, int pass) 99152592Sandre{ 100152592Sandre struct ip *ip = mtod(m, struct ip *); 101152592Sandre u_char *cp; 102152592Sandre struct in_ifaddr *ia; 103152592Sandre int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; 104152592Sandre struct in_addr *sin, dst; 105152592Sandre n_time ntime; 106152592Sandre struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET }; 107152592Sandre 108169464Srwatson /* Ignore or reject packets with IP options. */ 109152592Sandre if (ip_doopts == 0) 110152592Sandre return 0; 111152592Sandre else if (ip_doopts == 2) { 112152592Sandre type = ICMP_UNREACH; 113152592Sandre code = ICMP_UNREACH_FILTER_PROHIB; 114152592Sandre goto bad; 115152592Sandre } 116152592Sandre 117152592Sandre dst = ip->ip_dst; 118152592Sandre cp = (u_char *)(ip + 1); 119152592Sandre cnt = (ip->ip_hl << 2) - sizeof (struct ip); 120152592Sandre for (; cnt > 0; cnt -= optlen, cp += optlen) { 121152592Sandre opt = cp[IPOPT_OPTVAL]; 122152592Sandre if (opt == IPOPT_EOL) 123152592Sandre break; 124152592Sandre if (opt == IPOPT_NOP) 125152592Sandre optlen = 1; 126152592Sandre else { 127152592Sandre if (cnt < IPOPT_OLEN + sizeof(*cp)) { 128152592Sandre code = &cp[IPOPT_OLEN] - (u_char *)ip; 129152592Sandre goto bad; 130152592Sandre } 131152592Sandre optlen = cp[IPOPT_OLEN]; 132152592Sandre if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) { 133152592Sandre code = &cp[IPOPT_OLEN] - (u_char *)ip; 134152592Sandre goto bad; 135152592Sandre } 136152592Sandre } 137152592Sandre switch (opt) { 138152592Sandre 139152592Sandre default: 140152592Sandre break; 141152592Sandre 142152592Sandre /* 143169464Srwatson * Source routing with record. Find interface with current 144169464Srwatson * destination address. If none on this machine then drop if 145169464Srwatson * strictly routed, or do nothing if loosely routed. Record 146169464Srwatson * interface address and bring up next address component. If 147169464Srwatson * strictly routed make sure next address is on directly 148169464Srwatson * accessible net. 149152592Sandre */ 150152592Sandre case IPOPT_LSRR: 151152592Sandre case IPOPT_SSRR: 152152592Sandre#ifdef IPSTEALTH 153152592Sandre if (ipstealth && pass > 0) 154152592Sandre break; 155152592Sandre#endif 156152592Sandre if (optlen < IPOPT_OFFSET + sizeof(*cp)) { 157152592Sandre code = &cp[IPOPT_OLEN] - (u_char *)ip; 158152592Sandre goto bad; 159152592Sandre } 160152592Sandre if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 161152592Sandre code = &cp[IPOPT_OFFSET] - (u_char *)ip; 162152592Sandre goto bad; 163152592Sandre } 164152592Sandre ipaddr.sin_addr = ip->ip_dst; 165152592Sandre ia = (struct in_ifaddr *) 166152592Sandre ifa_ifwithaddr((struct sockaddr *)&ipaddr); 167152592Sandre if (ia == NULL) { 168152592Sandre if (opt == IPOPT_SSRR) { 169152592Sandre type = ICMP_UNREACH; 170152592Sandre code = ICMP_UNREACH_SRCFAIL; 171152592Sandre goto bad; 172152592Sandre } 173152592Sandre if (!ip_dosourceroute) 174152592Sandre goto nosourcerouting; 175152592Sandre /* 176152592Sandre * Loose routing, and not at next destination 177152592Sandre * yet; nothing to do except forward. 178152592Sandre */ 179152592Sandre break; 180152592Sandre } 181152592Sandre off--; /* 0 origin */ 182152592Sandre if (off > optlen - (int)sizeof(struct in_addr)) { 183152592Sandre /* 184152592Sandre * End of source route. Should be for us. 185152592Sandre */ 186152592Sandre if (!ip_acceptsourceroute) 187152592Sandre goto nosourcerouting; 188152592Sandre save_rte(m, cp, ip->ip_src); 189152592Sandre break; 190152592Sandre } 191152592Sandre#ifdef IPSTEALTH 192152592Sandre if (ipstealth) 193152592Sandre goto dropit; 194152592Sandre#endif 195152592Sandre if (!ip_dosourceroute) { 196152592Sandre if (ipforwarding) { 197152592Sandre char buf[16]; /* aaa.bbb.ccc.ddd\0 */ 198152592Sandre /* 199169464Srwatson * Acting as a router, so generate 200169464Srwatson * ICMP 201152592Sandre */ 202152592Sandrenosourcerouting: 203152592Sandre strcpy(buf, inet_ntoa(ip->ip_dst)); 204152592Sandre log(LOG_WARNING, 205152592Sandre "attempted source route from %s to %s\n", 206152592Sandre inet_ntoa(ip->ip_src), buf); 207152592Sandre type = ICMP_UNREACH; 208152592Sandre code = ICMP_UNREACH_SRCFAIL; 209152592Sandre goto bad; 210152592Sandre } else { 211152592Sandre /* 212169464Srwatson * Not acting as a router, so 213169464Srwatson * silently drop. 214152592Sandre */ 215152592Sandre#ifdef IPSTEALTH 216152592Sandredropit: 217152592Sandre#endif 218152592Sandre ipstat.ips_cantforward++; 219152592Sandre m_freem(m); 220152592Sandre return (1); 221152592Sandre } 222152592Sandre } 223152592Sandre 224152592Sandre /* 225152592Sandre * locate outgoing interface 226152592Sandre */ 227152592Sandre (void)memcpy(&ipaddr.sin_addr, cp + off, 228152592Sandre sizeof(ipaddr.sin_addr)); 229152592Sandre 230152592Sandre if (opt == IPOPT_SSRR) { 231152592Sandre#define INA struct in_ifaddr * 232152592Sandre#define SA struct sockaddr * 233152592Sandre if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == NULL) 234152592Sandre ia = (INA)ifa_ifwithnet((SA)&ipaddr); 235152592Sandre } else 236152592Sandre ia = ip_rtaddr(ipaddr.sin_addr); 237152592Sandre if (ia == NULL) { 238152592Sandre type = ICMP_UNREACH; 239152592Sandre code = ICMP_UNREACH_SRCFAIL; 240152592Sandre goto bad; 241152592Sandre } 242152592Sandre ip->ip_dst = ipaddr.sin_addr; 243152592Sandre (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr), 244152592Sandre sizeof(struct in_addr)); 245152592Sandre cp[IPOPT_OFFSET] += sizeof(struct in_addr); 246152592Sandre /* 247152592Sandre * Let ip_intr's mcast routing check handle mcast pkts 248152592Sandre */ 249152592Sandre forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr)); 250152592Sandre break; 251152592Sandre 252152592Sandre case IPOPT_RR: 253152592Sandre#ifdef IPSTEALTH 254152592Sandre if (ipstealth && pass == 0) 255152592Sandre break; 256152592Sandre#endif 257152592Sandre if (optlen < IPOPT_OFFSET + sizeof(*cp)) { 258152592Sandre code = &cp[IPOPT_OFFSET] - (u_char *)ip; 259152592Sandre goto bad; 260152592Sandre } 261152592Sandre if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { 262152592Sandre code = &cp[IPOPT_OFFSET] - (u_char *)ip; 263152592Sandre goto bad; 264152592Sandre } 265152592Sandre /* 266152592Sandre * If no space remains, ignore. 267152592Sandre */ 268152592Sandre off--; /* 0 origin */ 269152592Sandre if (off > optlen - (int)sizeof(struct in_addr)) 270152592Sandre break; 271152592Sandre (void)memcpy(&ipaddr.sin_addr, &ip->ip_dst, 272152592Sandre sizeof(ipaddr.sin_addr)); 273152592Sandre /* 274169464Srwatson * Locate outgoing interface; if we're the 275169464Srwatson * destination, use the incoming interface (should be 276169464Srwatson * same). 277152592Sandre */ 278152592Sandre if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL && 279152592Sandre (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) { 280152592Sandre type = ICMP_UNREACH; 281152592Sandre code = ICMP_UNREACH_HOST; 282152592Sandre goto bad; 283152592Sandre } 284152592Sandre (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr), 285152592Sandre sizeof(struct in_addr)); 286152592Sandre cp[IPOPT_OFFSET] += sizeof(struct in_addr); 287152592Sandre break; 288152592Sandre 289152592Sandre case IPOPT_TS: 290152592Sandre#ifdef IPSTEALTH 291152592Sandre if (ipstealth && pass == 0) 292152592Sandre break; 293152592Sandre#endif 294152592Sandre code = cp - (u_char *)ip; 295152592Sandre if (optlen < 4 || optlen > 40) { 296152592Sandre code = &cp[IPOPT_OLEN] - (u_char *)ip; 297152592Sandre goto bad; 298152592Sandre } 299152592Sandre if ((off = cp[IPOPT_OFFSET]) < 5) { 300152592Sandre code = &cp[IPOPT_OLEN] - (u_char *)ip; 301152592Sandre goto bad; 302152592Sandre } 303152592Sandre if (off > optlen - (int)sizeof(int32_t)) { 304152592Sandre cp[IPOPT_OFFSET + 1] += (1 << 4); 305152592Sandre if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) { 306152592Sandre code = &cp[IPOPT_OFFSET] - (u_char *)ip; 307152592Sandre goto bad; 308152592Sandre } 309152592Sandre break; 310152592Sandre } 311152592Sandre off--; /* 0 origin */ 312152592Sandre sin = (struct in_addr *)(cp + off); 313152592Sandre switch (cp[IPOPT_OFFSET + 1] & 0x0f) { 314152592Sandre 315152592Sandre case IPOPT_TS_TSONLY: 316152592Sandre break; 317152592Sandre 318152592Sandre case IPOPT_TS_TSANDADDR: 319152592Sandre if (off + sizeof(n_time) + 320152592Sandre sizeof(struct in_addr) > optlen) { 321152592Sandre code = &cp[IPOPT_OFFSET] - (u_char *)ip; 322152592Sandre goto bad; 323152592Sandre } 324152592Sandre ipaddr.sin_addr = dst; 325152592Sandre ia = (INA)ifaof_ifpforaddr((SA)&ipaddr, 326152592Sandre m->m_pkthdr.rcvif); 327152592Sandre if (ia == NULL) 328152592Sandre continue; 329152592Sandre (void)memcpy(sin, &IA_SIN(ia)->sin_addr, 330152592Sandre sizeof(struct in_addr)); 331152592Sandre cp[IPOPT_OFFSET] += sizeof(struct in_addr); 332152592Sandre off += sizeof(struct in_addr); 333152592Sandre break; 334152592Sandre 335152592Sandre case IPOPT_TS_PRESPEC: 336152592Sandre if (off + sizeof(n_time) + 337152592Sandre sizeof(struct in_addr) > optlen) { 338152592Sandre code = &cp[IPOPT_OFFSET] - (u_char *)ip; 339152592Sandre goto bad; 340152592Sandre } 341152592Sandre (void)memcpy(&ipaddr.sin_addr, sin, 342152592Sandre sizeof(struct in_addr)); 343152592Sandre if (ifa_ifwithaddr((SA)&ipaddr) == NULL) 344152592Sandre continue; 345152592Sandre cp[IPOPT_OFFSET] += sizeof(struct in_addr); 346152592Sandre off += sizeof(struct in_addr); 347152592Sandre break; 348152592Sandre 349152592Sandre default: 350152592Sandre code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip; 351152592Sandre goto bad; 352152592Sandre } 353152592Sandre ntime = iptime(); 354152592Sandre (void)memcpy(cp + off, &ntime, sizeof(n_time)); 355152592Sandre cp[IPOPT_OFFSET] += sizeof(n_time); 356152592Sandre } 357152592Sandre } 358152592Sandre if (forward && ipforwarding) { 359152592Sandre ip_forward(m, 1); 360152592Sandre return (1); 361152592Sandre } 362152592Sandre return (0); 363152592Sandrebad: 364152592Sandre icmp_error(m, type, code, 0, 0); 365152592Sandre ipstat.ips_badoptions++; 366152592Sandre return (1); 367152592Sandre} 368152592Sandre 369152592Sandre/* 370169464Srwatson * Save incoming source route for use in replies, to be picked up later by 371169464Srwatson * ip_srcroute if the receiver is interested. 372152592Sandre */ 373152592Sandrestatic void 374169454Srwatsonsave_rte(struct mbuf *m, u_char *option, struct in_addr dst) 375152592Sandre{ 376152592Sandre unsigned olen; 377152592Sandre struct ipopt_tag *opts; 378152592Sandre 379152592Sandre opts = (struct ipopt_tag *)m_tag_get(PACKET_TAG_IPOPTIONS, 380169464Srwatson sizeof(struct ipopt_tag), M_NOWAIT); 381152592Sandre if (opts == NULL) 382152592Sandre return; 383152592Sandre 384152592Sandre olen = option[IPOPT_OLEN]; 385152592Sandre if (olen > sizeof(opts->ip_srcrt) - (1 + sizeof(dst))) { 386152592Sandre m_tag_free((struct m_tag *)opts); 387152592Sandre return; 388152592Sandre } 389152592Sandre bcopy(option, opts->ip_srcrt.srcopt, olen); 390152592Sandre opts->ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); 391152592Sandre opts->ip_srcrt.dst = dst; 392152592Sandre m_tag_prepend(m, (struct m_tag *)opts); 393152592Sandre} 394152592Sandre 395152592Sandre/* 396169464Srwatson * Retrieve incoming source route for use in replies, in the same form used 397169464Srwatson * by setsockopt. The first hop is placed before the options, will be 398169464Srwatson * removed later. 399152592Sandre */ 400152592Sandrestruct mbuf * 401169454Srwatsonip_srcroute(struct mbuf *m0) 402152592Sandre{ 403169464Srwatson struct in_addr *p, *q; 404169464Srwatson struct mbuf *m; 405152592Sandre struct ipopt_tag *opts; 406152592Sandre 407152592Sandre opts = (struct ipopt_tag *)m_tag_find(m0, PACKET_TAG_IPOPTIONS, NULL); 408152592Sandre if (opts == NULL) 409152592Sandre return (NULL); 410152592Sandre 411152592Sandre if (opts->ip_nhops == 0) 412152592Sandre return (NULL); 413152592Sandre m = m_get(M_DONTWAIT, MT_DATA); 414152592Sandre if (m == NULL) 415152592Sandre return (NULL); 416152592Sandre 417152592Sandre#define OPTSIZ (sizeof(opts->ip_srcrt.nop) + sizeof(opts->ip_srcrt.srcopt)) 418152592Sandre 419152592Sandre /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ 420152592Sandre m->m_len = opts->ip_nhops * sizeof(struct in_addr) + 421152592Sandre sizeof(struct in_addr) + OPTSIZ; 422152592Sandre 423152592Sandre /* 424169464Srwatson * First, save first hop for return route. 425152592Sandre */ 426152592Sandre p = &(opts->ip_srcrt.route[opts->ip_nhops - 1]); 427152592Sandre *(mtod(m, struct in_addr *)) = *p--; 428152592Sandre 429152592Sandre /* 430152592Sandre * Copy option fields and padding (nop) to mbuf. 431152592Sandre */ 432152592Sandre opts->ip_srcrt.nop = IPOPT_NOP; 433152592Sandre opts->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; 434152592Sandre (void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), 435152592Sandre &(opts->ip_srcrt.nop), OPTSIZ); 436152592Sandre q = (struct in_addr *)(mtod(m, caddr_t) + 437152592Sandre sizeof(struct in_addr) + OPTSIZ); 438152592Sandre#undef OPTSIZ 439152592Sandre /* 440169464Srwatson * Record return path as an IP source route, reversing the path 441169464Srwatson * (pointers are now aligned). 442152592Sandre */ 443152592Sandre while (p >= opts->ip_srcrt.route) { 444152592Sandre *q++ = *p--; 445152592Sandre } 446152592Sandre /* 447152592Sandre * Last hop goes to final destination. 448152592Sandre */ 449152592Sandre *q = opts->ip_srcrt.dst; 450152592Sandre m_tag_delete(m0, (struct m_tag *)opts); 451152592Sandre return (m); 452152592Sandre} 453152592Sandre 454152592Sandre/* 455169464Srwatson * Strip out IP options, at higher level protocol in the kernel. Second 456169464Srwatson * argument is buffer to which options will be moved, and return value is 457169464Srwatson * their length. 458169464Srwatson * 459152592Sandre * XXX should be deleted; last arg currently ignored. 460152592Sandre */ 461152592Sandrevoid 462169454Srwatsonip_stripoptions(struct mbuf *m, struct mbuf *mopt) 463152592Sandre{ 464169464Srwatson int i; 465152592Sandre struct ip *ip = mtod(m, struct ip *); 466169464Srwatson caddr_t opts; 467152592Sandre int olen; 468152592Sandre 469152592Sandre olen = (ip->ip_hl << 2) - sizeof (struct ip); 470152592Sandre opts = (caddr_t)(ip + 1); 471152592Sandre i = m->m_len - (sizeof (struct ip) + olen); 472152592Sandre bcopy(opts + olen, opts, (unsigned)i); 473152592Sandre m->m_len -= olen; 474152592Sandre if (m->m_flags & M_PKTHDR) 475152592Sandre m->m_pkthdr.len -= olen; 476152592Sandre ip->ip_v = IPVERSION; 477152592Sandre ip->ip_hl = sizeof(struct ip) >> 2; 478152592Sandre} 479152592Sandre 480152592Sandre/* 481169464Srwatson * Insert IP options into preformed packet. Adjust IP destination as 482169464Srwatson * required for IP source routing, as indicated by a non-zero in_addr at the 483169464Srwatson * start of the options. 484152592Sandre * 485152592Sandre * XXX This routine assumes that the packet has no options in place. 486152592Sandre */ 487152592Sandrestruct mbuf * 488169454Srwatsonip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 489152592Sandre{ 490169464Srwatson struct ipoption *p = mtod(opt, struct ipoption *); 491152592Sandre struct mbuf *n; 492169464Srwatson struct ip *ip = mtod(m, struct ip *); 493152592Sandre unsigned optlen; 494152592Sandre 495152592Sandre optlen = opt->m_len - sizeof(p->ipopt_dst); 496152592Sandre if (optlen + ip->ip_len > IP_MAXPACKET) { 497152592Sandre *phlen = 0; 498152592Sandre return (m); /* XXX should fail */ 499152592Sandre } 500152592Sandre if (p->ipopt_dst.s_addr) 501152592Sandre ip->ip_dst = p->ipopt_dst; 502152592Sandre if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 503152592Sandre MGETHDR(n, M_DONTWAIT, MT_DATA); 504152592Sandre if (n == NULL) { 505152592Sandre *phlen = 0; 506152592Sandre return (m); 507152592Sandre } 508152592Sandre M_MOVE_PKTHDR(n, m); 509152592Sandre n->m_pkthdr.rcvif = NULL; 510152592Sandre#ifdef MAC 511172930Srwatson mac_mbuf_copy(m, n); 512152592Sandre#endif 513152592Sandre n->m_pkthdr.len += optlen; 514152592Sandre m->m_len -= sizeof(struct ip); 515152592Sandre m->m_data += sizeof(struct ip); 516152592Sandre n->m_next = m; 517152592Sandre m = n; 518152592Sandre m->m_len = optlen + sizeof(struct ip); 519152592Sandre m->m_data += max_linkhdr; 520152592Sandre bcopy(ip, mtod(m, void *), sizeof(struct ip)); 521152592Sandre } else { 522152592Sandre m->m_data -= optlen; 523152592Sandre m->m_len += optlen; 524152592Sandre m->m_pkthdr.len += optlen; 525152592Sandre bcopy(ip, mtod(m, void *), sizeof(struct ip)); 526152592Sandre } 527152592Sandre ip = mtod(m, struct ip *); 528152592Sandre bcopy(p->ipopt_list, ip + 1, optlen); 529152592Sandre *phlen = sizeof(struct ip) + optlen; 530152592Sandre ip->ip_v = IPVERSION; 531152592Sandre ip->ip_hl = *phlen >> 2; 532152592Sandre ip->ip_len += optlen; 533152592Sandre return (m); 534152592Sandre} 535152592Sandre 536152592Sandre/* 537169464Srwatson * Copy options from ip to jp, omitting those not copied during 538169464Srwatson * fragmentation. 539152592Sandre */ 540152592Sandreint 541169454Srwatsonip_optcopy(struct ip *ip, struct ip *jp) 542152592Sandre{ 543169464Srwatson u_char *cp, *dp; 544152592Sandre int opt, optlen, cnt; 545152592Sandre 546152592Sandre cp = (u_char *)(ip + 1); 547152592Sandre dp = (u_char *)(jp + 1); 548152592Sandre cnt = (ip->ip_hl << 2) - sizeof (struct ip); 549152592Sandre for (; cnt > 0; cnt -= optlen, cp += optlen) { 550152592Sandre opt = cp[0]; 551152592Sandre if (opt == IPOPT_EOL) 552152592Sandre break; 553152592Sandre if (opt == IPOPT_NOP) { 554152592Sandre /* Preserve for IP mcast tunnel's LSRR alignment. */ 555152592Sandre *dp++ = IPOPT_NOP; 556152592Sandre optlen = 1; 557152592Sandre continue; 558152592Sandre } 559152592Sandre 560152592Sandre KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp), 561152592Sandre ("ip_optcopy: malformed ipv4 option")); 562152592Sandre optlen = cp[IPOPT_OLEN]; 563152592Sandre KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen <= cnt, 564152592Sandre ("ip_optcopy: malformed ipv4 option")); 565152592Sandre 566169464Srwatson /* Bogus lengths should have been caught by ip_dooptions. */ 567152592Sandre if (optlen > cnt) 568152592Sandre optlen = cnt; 569152592Sandre if (IPOPT_COPIED(opt)) { 570152592Sandre bcopy(cp, dp, optlen); 571152592Sandre dp += optlen; 572152592Sandre } 573152592Sandre } 574152592Sandre for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 575152592Sandre *dp++ = IPOPT_EOL; 576152592Sandre return (optlen); 577152592Sandre} 578152592Sandre 579152592Sandre/* 580169464Srwatson * Set up IP options in pcb for insertion in output packets. Store in mbuf 581169464Srwatson * with pointer in pcbopt, adding pseudo-option with destination address if 582169464Srwatson * source routed. 583152592Sandre */ 584152592Sandreint 585152592Sandreip_pcbopts(struct inpcb *inp, int optname, struct mbuf *m) 586152592Sandre{ 587169464Srwatson int cnt, optlen; 588169464Srwatson u_char *cp; 589152592Sandre struct mbuf **pcbopt; 590152592Sandre u_char opt; 591152592Sandre 592152592Sandre INP_LOCK_ASSERT(inp); 593152592Sandre 594152592Sandre pcbopt = &inp->inp_options; 595152592Sandre 596152592Sandre /* turn off any old options */ 597152592Sandre if (*pcbopt) 598152592Sandre (void)m_free(*pcbopt); 599152592Sandre *pcbopt = 0; 600152592Sandre if (m == NULL || m->m_len == 0) { 601152592Sandre /* 602152592Sandre * Only turning off any previous options. 603152592Sandre */ 604152592Sandre if (m != NULL) 605152592Sandre (void)m_free(m); 606152592Sandre return (0); 607152592Sandre } 608152592Sandre 609152592Sandre if (m->m_len % sizeof(int32_t)) 610152592Sandre goto bad; 611152592Sandre /* 612169464Srwatson * IP first-hop destination address will be stored before actual 613169464Srwatson * options; move other options back and clear it when none present. 614152592Sandre */ 615152592Sandre if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 616152592Sandre goto bad; 617152592Sandre cnt = m->m_len; 618152592Sandre m->m_len += sizeof(struct in_addr); 619152592Sandre cp = mtod(m, u_char *) + sizeof(struct in_addr); 620152592Sandre bcopy(mtod(m, void *), cp, (unsigned)cnt); 621152592Sandre bzero(mtod(m, void *), sizeof(struct in_addr)); 622152592Sandre 623152592Sandre for (; cnt > 0; cnt -= optlen, cp += optlen) { 624152592Sandre opt = cp[IPOPT_OPTVAL]; 625152592Sandre if (opt == IPOPT_EOL) 626152592Sandre break; 627152592Sandre if (opt == IPOPT_NOP) 628152592Sandre optlen = 1; 629152592Sandre else { 630152592Sandre if (cnt < IPOPT_OLEN + sizeof(*cp)) 631152592Sandre goto bad; 632152592Sandre optlen = cp[IPOPT_OLEN]; 633152592Sandre if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 634152592Sandre goto bad; 635152592Sandre } 636152592Sandre switch (opt) { 637152592Sandre 638152592Sandre default: 639152592Sandre break; 640152592Sandre 641152592Sandre case IPOPT_LSRR: 642152592Sandre case IPOPT_SSRR: 643152592Sandre /* 644169464Srwatson * User process specifies route as: 645169464Srwatson * 646152592Sandre * ->A->B->C->D 647169464Srwatson * 648152592Sandre * D must be our final destination (but we can't 649152592Sandre * check that since we may not have connected yet). 650169464Srwatson * A is first hop destination, which doesn't appear 651169464Srwatson * in actual IP option, but is stored before the 652169464Srwatson * options. 653152592Sandre */ 654175630Sbz /* XXX-BZ PRIV_NETINET_SETHDROPTS? */ 655152592Sandre if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 656152592Sandre goto bad; 657152592Sandre m->m_len -= sizeof(struct in_addr); 658152592Sandre cnt -= sizeof(struct in_addr); 659152592Sandre optlen -= sizeof(struct in_addr); 660152592Sandre cp[IPOPT_OLEN] = optlen; 661152592Sandre /* 662152592Sandre * Move first hop before start of options. 663152592Sandre */ 664152592Sandre bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 665152592Sandre sizeof(struct in_addr)); 666152592Sandre /* 667152592Sandre * Then copy rest of options back 668152592Sandre * to close up the deleted entry. 669152592Sandre */ 670152592Sandre bcopy((&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), 671152592Sandre &cp[IPOPT_OFFSET+1], 672152592Sandre (unsigned)cnt - (IPOPT_MINOFF - 1)); 673152592Sandre break; 674152592Sandre } 675152592Sandre } 676152592Sandre if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 677152592Sandre goto bad; 678152592Sandre *pcbopt = m; 679152592Sandre return (0); 680152592Sandre 681152592Sandrebad: 682152592Sandre (void)m_free(m); 683152592Sandre return (EINVAL); 684152592Sandre} 685