1 /* $NetBSD: nfs_boot.c,v 1.50 1999/02/21 15:07:49 drochner Exp $ */ 2 3 /*- 4 * Copyright (c) 1995, 1997 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Adam Glass and Gordon W. Ross. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * Support for NFS diskless booting, specifically getting information 41 * about where to mount root from, what pathnames, etc. 42 */ 43 44 #include "opt_nfs_boot.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/kernel.h> 49 #include <sys/conf.h> 50 #include <sys/device.h> 51 #include <sys/ioctl.h> 52 #include <sys/proc.h> 53 #include <sys/mount.h> 54 #include <sys/mbuf.h> 55 #include <sys/reboot.h> 56 #include <sys/socket.h> 57 #include <sys/socketvar.h> 58 59 #include <net/if.h> 60 #include <net/route.h> 61 #include <net/if_ether.h> 62 #include <net/if_types.h> 63 64 #include <netinet/in.h> 65 #include <netinet/if_inarp.h> 66 67 #include <nfs/rpcv2.h> 68 #include <nfs/krpc.h> 69 #include <nfs/xdr_subs.h> 70 71 #include <nfs/nfsproto.h> 72 #include <nfs/nfs.h> 73 #include <nfs/nfsmount.h> 74 #include <nfs/nfsdiskless.h> 75 76 /* 77 * There are two implementations of NFS diskless boot. 78 * One implementation uses BOOTP (RFC951, RFC1048), 79 * the other uses Sun RPC/bootparams. See the files: 80 * nfs_bootp.c: BOOTP (RFC951, RFC1048) 81 * nfs_bootsun.c: Sun RPC/bootparams 82 */ 83 #if defined(NFS_BOOT_BOOTP) || defined(NFS_BOOT_DHCP) 84 int nfs_boot_rfc951 = 1; /* BOOTP enabled (default) */ 85 #endif 86 #ifdef NFS_BOOT_BOOTPARAM 87 int nfs_boot_bootparam = 1; /* BOOTPARAM enabled (default) */ 88 #endif 89 90 /* mountd RPC */ 91 static int md_mount __P((struct sockaddr_in *mdsin, char *path, 92 struct nfs_args *argp)); 93 94 static void nfs_boot_defrt __P((struct in_addr *)); 95 static int nfs_boot_getfh __P((struct nfs_dlmount *ndm)); 96 97 98 /* 99 * Called with an empty nfs_diskless struct to be filled in. 100 * Find an interface, determine its ip address (etc.) and 101 * save all the boot parameters in the nfs_diskless struct. 102 */ 103 int 104 nfs_boot_init(nd, procp) 105 struct nfs_diskless *nd; 106 struct proc *procp; 107 { 108 struct ifnet *ifp; 109 int error; 110 111 /* 112 * Find the network interface. 113 */ 114 ifp = ifunit(root_device->dv_xname); 115 if (ifp == NULL) { 116 printf("nfs_boot: '%s' not found\n", 117 root_device->dv_xname); 118 return (ENXIO); 119 } 120 nd->nd_ifp = ifp; 121 122 error = EADDRNOTAVAIL; /* ??? */ 123 #if defined(NFS_BOOT_BOOTP) || defined(NFS_BOOT_DHCP) 124 if (error && nfs_boot_rfc951) { 125 #if defined(NFS_BOOT_DHCP) 126 printf("nfs_boot: trying DHCP/BOOTP\n"); 127 #else 128 printf("nfs_boot: trying BOOTP\n"); 129 #endif 130 error = nfs_bootdhcp(nd, procp); 131 } 132 #endif 133 #ifdef NFS_BOOT_BOOTPARAM 134 if (error && nfs_boot_bootparam) { 135 printf("nfs_boot: trying RARP (and RPC/bootparam)\n"); 136 error = nfs_bootparam(nd, procp); 137 } 138 #endif 139 if (error) 140 return (error); 141 142 /* 143 * If the gateway address is set, add a default route. 144 * (The mountd RPCs may go across a gateway.) 145 */ 146 if (nd->nd_gwip.s_addr) 147 nfs_boot_defrt(&nd->nd_gwip); 148 149 /* 150 * Now fetch the NFS file handles as appropriate. 151 */ 152 error = nfs_boot_getfh(&nd->nd_root); 153 154 if (error) 155 nfs_boot_cleanup(nd, procp); 156 157 return (error); 158 } 159 160 void 161 nfs_boot_cleanup(nd, procp) 162 struct nfs_diskless *nd; 163 struct proc *procp; 164 { 165 166 nfs_boot_deladdress(nd->nd_ifp, procp, nd->nd_myip.s_addr); 167 nfs_boot_ifupdown(nd->nd_ifp, procp, 0); 168 nfs_boot_flushrt(nd->nd_ifp); 169 } 170 171 int 172 nfs_boot_ifupdown(ifp, procp, up) 173 struct ifnet *ifp; 174 struct proc *procp; 175 int up; 176 { 177 struct socket *so; 178 struct ifreq ireq; 179 int error; 180 181 memset(&ireq, 0, sizeof(ireq)); 182 memcpy(ireq.ifr_name, ifp->if_xname, IFNAMSIZ); 183 184 /* 185 * Get a socket to use for various things in here. 186 * After this, use "goto out" to cleanup and return. 187 */ 188 error = socreate(AF_INET, &so, SOCK_DGRAM, 0); 189 if (error) { 190 printf("ifupdown: socreate, error=%d\n", error); 191 return (error); 192 } 193 194 /* 195 * Bring up the interface. (just set the "up" flag) 196 * Get the old interface flags and or IFF_UP into them so 197 * things like media selection flags are not clobbered. 198 */ 199 error = ifioctl(so, SIOCGIFFLAGS, (caddr_t)&ireq, procp); 200 if (error) { 201 printf("ifupdown: GIFFLAGS, error=%d\n", error); 202 goto out; 203 } 204 if (up) 205 ireq.ifr_flags |= IFF_UP; 206 else 207 ireq.ifr_flags &= ~IFF_UP; 208 error = ifioctl(so, SIOCSIFFLAGS, (caddr_t)&ireq, procp); 209 if (error) { 210 printf("ifupdown: SIFFLAGS, error=%d\n", error); 211 goto out; 212 } 213 214 out: 215 soclose(so); 216 return (error); 217 } 218 219 int 220 nfs_boot_setaddress(ifp, procp, addr, netmask, braddr) 221 struct ifnet *ifp; 222 struct proc *procp; 223 u_int32_t addr, netmask, braddr; 224 { 225 struct socket *so; 226 struct ifaliasreq iareq; 227 struct sockaddr_in *sin; 228 int error; 229 230 /* 231 * Get a socket to use for various things in here. 232 * After this, use "goto out" to cleanup and return. 233 */ 234 error = socreate(AF_INET, &so, SOCK_DGRAM, 0); 235 if (error) { 236 printf("setaddress: socreate, error=%d\n", error); 237 return (error); 238 } 239 240 memset(&iareq, 0, sizeof(iareq)); 241 memcpy(iareq.ifra_name, ifp->if_xname, IFNAMSIZ); 242 243 /* Set the I/F address */ 244 sin = (struct sockaddr_in *)&iareq.ifra_addr; 245 sin->sin_len = sizeof(*sin); 246 sin->sin_family = AF_INET; 247 sin->sin_addr.s_addr = addr; 248 249 /* Set the netmask */ 250 if (netmask != INADDR_ANY) { 251 sin = (struct sockaddr_in *)&iareq.ifra_mask; 252 sin->sin_len = sizeof(*sin); 253 sin->sin_family = AF_INET; 254 sin->sin_addr.s_addr = netmask; 255 } /* else leave subnetmask unspecified (len=0) */ 256 257 /* Set the broadcast addr. */ 258 if (braddr != INADDR_ANY) { 259 sin = (struct sockaddr_in *)&iareq.ifra_broadaddr; 260 sin->sin_len = sizeof(*sin); 261 sin->sin_family = AF_INET; 262 sin->sin_addr.s_addr = braddr; 263 } /* else leave broadcast addr unspecified (len=0) */ 264 265 error = ifioctl(so, SIOCAIFADDR, (caddr_t)&iareq, procp); 266 if (error) { 267 printf("setaddress, error=%d\n", error); 268 goto out; 269 } 270 271 out: 272 soclose(so); 273 return (error); 274 } 275 276 int 277 nfs_boot_deladdress(ifp, procp, addr) 278 struct ifnet *ifp; 279 struct proc *procp; 280 u_int32_t addr; 281 { 282 struct socket *so; 283 struct ifreq ireq; 284 struct sockaddr_in *sin; 285 int error; 286 287 /* 288 * Get a socket to use for various things in here. 289 * After this, use "goto out" to cleanup and return. 290 */ 291 error = socreate(AF_INET, &so, SOCK_DGRAM, 0); 292 if (error) { 293 printf("deladdress: socreate, error=%d\n", error); 294 return (error); 295 } 296 297 memset(&ireq, 0, sizeof(ireq)); 298 memcpy(ireq.ifr_name, ifp->if_xname, IFNAMSIZ); 299 300 sin = (struct sockaddr_in *)&ireq.ifr_addr; 301 sin->sin_len = sizeof(*sin); 302 sin->sin_family = AF_INET; 303 sin->sin_addr.s_addr = addr; 304 305 error = ifioctl(so, SIOCDIFADDR, (caddr_t)&ireq, procp); 306 if (error) { 307 printf("deladdress, error=%d\n", error); 308 goto out; 309 } 310 311 out: 312 soclose(so); 313 return (error); 314 } 315 316 int 317 nfs_boot_setrecvtimo(so) 318 struct socket *so; 319 { 320 struct mbuf *m; 321 struct timeval *tv; 322 323 m = m_get(M_WAIT, MT_SOOPTS); 324 tv = mtod(m, struct timeval *); 325 m->m_len = sizeof(*tv); 326 tv->tv_sec = 1; 327 tv->tv_usec = 0; 328 return (sosetopt(so, SOL_SOCKET, SO_RCVTIMEO, m)); 329 } 330 331 int 332 nfs_boot_enbroadcast(so) 333 struct socket *so; 334 { 335 struct mbuf *m; 336 int32_t *on; 337 338 m = m_get(M_WAIT, MT_SOOPTS); 339 on = mtod(m, int32_t *); 340 m->m_len = sizeof(*on); 341 *on = 1; 342 return (sosetopt(so, SOL_SOCKET, SO_BROADCAST, m)); 343 } 344 345 int 346 nfs_boot_sobind_ipport(so, port) 347 struct socket *so; 348 u_int16_t port; 349 { 350 struct mbuf *m; 351 struct sockaddr_in *sin; 352 int error; 353 354 m = m_getclr(M_WAIT, MT_SONAME); 355 sin = mtod(m, struct sockaddr_in *); 356 sin->sin_len = m->m_len = sizeof(*sin); 357 sin->sin_family = AF_INET; 358 sin->sin_addr.s_addr = INADDR_ANY; 359 sin->sin_port = htons(port); 360 error = sobind(so, m); 361 m_freem(m); 362 return (error); 363 } 364 365 /* 366 * What is the longest we will wait before re-sending a request? 367 * Note this is also the frequency of "timeout" messages. 368 * The re-send loop counts up linearly to this maximum, so the 369 * first complaint will happen after (1+2+3+4+5)=15 seconds. 370 */ 371 #define MAX_RESEND_DELAY 5 /* seconds */ 372 #define TOTAL_TIMEOUT 30 /* seconds */ 373 374 int 375 nfs_boot_sendrecv(so, nam, sndproc, snd, rcvproc, rcv, from_p, context) 376 struct socket *so; 377 struct mbuf *nam; 378 int (*sndproc) __P((struct mbuf*, void*, int)); 379 struct mbuf *snd; 380 int (*rcvproc) __P((struct mbuf*, void*)); 381 struct mbuf **rcv, **from_p; 382 void *context; 383 { 384 int error, rcvflg, timo, secs, waited; 385 struct mbuf *m, *from; 386 struct uio uio; 387 388 /* Free at end if not null. */ 389 from = NULL; 390 391 /* 392 * Send it, repeatedly, until a reply is received, 393 * but delay each re-send by an increasing amount. 394 * If the delay hits the maximum, start complaining. 395 */ 396 waited = timo = 0; 397 send_again: 398 waited += timo; 399 if (waited >= TOTAL_TIMEOUT) 400 return (ETIMEDOUT); 401 402 /* Determine new timeout. */ 403 if (timo < MAX_RESEND_DELAY) 404 timo++; 405 else 406 printf("nfs_boot: timeout...\n"); 407 408 if (sndproc) { 409 error = (*sndproc)(snd, context, waited); 410 if (error) 411 goto out; 412 } 413 414 /* Send request (or re-send). */ 415 m = m_copypacket(snd, M_WAIT); 416 if (m == NULL) { 417 error = ENOBUFS; 418 goto out; 419 } 420 error = (*so->so_send)(so, nam, NULL, m, NULL, 0); 421 if (error) { 422 printf("nfs_boot: sosend: %d\n", error); 423 goto out; 424 } 425 m = NULL; 426 427 /* 428 * Wait for up to timo seconds for a reply. 429 * The socket receive timeout was set to 1 second. 430 */ 431 432 secs = timo; 433 for (;;) { 434 if (from) { 435 m_freem(from); 436 from = NULL; 437 } 438 if (m) { 439 m_freem(m); 440 m = NULL; 441 } 442 uio.uio_resid = 1 << 16; /* ??? */ 443 rcvflg = 0; 444 error = (*so->so_receive)(so, &from, &uio, &m, NULL, &rcvflg); 445 if (error == EWOULDBLOCK) { 446 if (--secs <= 0) 447 goto send_again; 448 continue; 449 } 450 if (error) 451 goto out; 452 #ifdef DIAGNOSTIC 453 if (!m || !(m->m_flags & M_PKTHDR) 454 || (1 << 16) - uio.uio_resid != m->m_pkthdr.len) 455 panic("nfs_boot_sendrecv: return size"); 456 #endif 457 458 if ((*rcvproc)(m, context)) 459 continue; 460 461 if (rcv) 462 *rcv = m; 463 else 464 m_freem(m); 465 if (from_p) { 466 *from_p = from; 467 from = NULL; 468 } 469 break; 470 } 471 out: 472 if (from) m_freem(from); 473 return (error); 474 } 475 476 /* 477 * Install a default route to the passed IP address. 478 */ 479 static void 480 nfs_boot_defrt(gw_ip) 481 struct in_addr *gw_ip; 482 { 483 struct sockaddr dst, gw, mask; 484 struct sockaddr_in *sin; 485 int error; 486 487 /* Destination: (default) */ 488 memset((caddr_t)&dst, 0, sizeof(dst)); 489 dst.sa_len = sizeof(dst); 490 dst.sa_family = AF_INET; 491 /* Gateway: */ 492 memset((caddr_t)&gw, 0, sizeof(gw)); 493 sin = (struct sockaddr_in *)&gw; 494 sin->sin_len = sizeof(*sin); 495 sin->sin_family = AF_INET; 496 sin->sin_addr.s_addr = gw_ip->s_addr; 497 /* Mask: (zero length) */ 498 /* XXX - Just pass a null pointer? */ 499 memset(&mask, 0, sizeof(mask)); 500 501 /* add, dest, gw, mask, flags, 0 */ 502 error = rtrequest(RTM_ADD, &dst, &gw, &mask, 503 (RTF_UP | RTF_GATEWAY | RTF_STATIC), NULL); 504 if (error) { 505 printf("nfs_boot: add route, error=%d\n", error); 506 error = 0; 507 } 508 } 509 510 static int nfs_boot_delroute __P((struct radix_node *, void *)); 511 static int 512 nfs_boot_delroute(rn, w) 513 struct radix_node *rn; 514 void *w; 515 { 516 struct rtentry *rt = (struct rtentry *)rn; 517 int error; 518 519 if (rt->rt_ifp != (struct ifnet *)w) 520 return (0); 521 522 error = rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 0, NULL); 523 if (error) 524 printf("nfs_boot: del route, error=%d\n", error); 525 526 return (0); 527 } 528 529 void 530 nfs_boot_flushrt(ifp) 531 struct ifnet *ifp; 532 { 533 534 rn_walktree(rt_tables[AF_INET], nfs_boot_delroute, ifp); 535 } 536 537 /* 538 * Get an initial NFS file handle using Sun RPC/mountd. 539 * Separate function because we used to call it twice. 540 * (once for root and once for swap) 541 */ 542 static int 543 nfs_boot_getfh(ndm) 544 struct nfs_dlmount *ndm; /* output */ 545 { 546 struct nfs_args *args; 547 struct sockaddr_in *sin; 548 char *pathname; 549 int error; 550 u_int16_t port; 551 552 args = &ndm->ndm_args; 553 554 /* Initialize mount args. */ 555 memset((caddr_t) args, 0, sizeof(*args)); 556 args->addr = &ndm->ndm_saddr; 557 args->addrlen = args->addr->sa_len; 558 #ifdef NFS_BOOT_TCP 559 args->sotype = SOCK_STREAM; 560 #else 561 args->sotype = SOCK_DGRAM; 562 #endif 563 args->fh = ndm->ndm_fh; 564 args->hostname = ndm->ndm_host; 565 args->flags = NFSMNT_RESVPORT | NFSMNT_NFSV3; 566 567 #ifdef NFS_BOOT_OPTIONS 568 args->flags |= NFS_BOOT_OPTIONS; 569 #endif 570 #ifdef NFS_BOOT_RWSIZE 571 /* 572 * Reduce rsize,wsize for interfaces that consistently 573 * drop fragments of long UDP messages. (i.e. wd8003). 574 * You can always change these later via remount. 575 */ 576 args->flags |= NFSMNT_WSIZE | NFSMNT_RSIZE; 577 args->wsize = NFS_BOOT_RWSIZE; 578 args->rsize = NFS_BOOT_RWSIZE; 579 #endif 580 581 /* 582 * Find the pathname part of the "server:pathname" 583 * string left in ndm->ndm_host by nfs_boot_init. 584 */ 585 pathname = strchr(ndm->ndm_host, ':'); 586 if (pathname == 0) { 587 printf("nfs_boot: getfh - no pathname\n"); 588 return (EIO); 589 } 590 pathname++; 591 592 /* 593 * Get file handle using RPC to mountd/mount 594 */ 595 sin = (struct sockaddr_in *)&ndm->ndm_saddr; 596 error = md_mount(sin, pathname, args); 597 if (error) { 598 printf("nfs_boot: mountd `%s', error=%d\n", 599 ndm->ndm_host, error); 600 return (error); 601 } 602 603 /* Set port number for NFS use. */ 604 /* XXX: NFS port is always 2049, right? */ 605 #ifdef NFS_BOOT_TCP 606 retry: 607 #endif 608 error = krpc_portmap(sin, NFS_PROG, 609 (args->flags & NFSMNT_NFSV3) ? NFS_VER3 : NFS_VER2, 610 (args->sotype == SOCK_STREAM) ? IPPROTO_TCP : IPPROTO_UDP, 611 &port); 612 if (port == htons(0)) 613 error = EIO; 614 if (error) { 615 #ifdef NFS_BOOT_TCP 616 if (args->sotype == SOCK_STREAM) { 617 args->sotype = SOCK_DGRAM; 618 goto retry; 619 } 620 #endif 621 printf("nfs_boot: portmap NFS, error=%d\n", error); 622 return (error); 623 } 624 sin->sin_port = port; 625 return (0); 626 } 627 628 629 /* 630 * RPC: mountd/mount 631 * Given a server pathname, get an NFS file handle. 632 * Also, sets sin->sin_port to the NFS service port. 633 */ 634 static int 635 md_mount(mdsin, path, argp) 636 struct sockaddr_in *mdsin; /* mountd server address */ 637 char *path; 638 struct nfs_args *argp; 639 { 640 /* The RPC structures */ 641 struct rdata { 642 u_int32_t errno; 643 union { 644 u_int8_t v2fh[NFSX_V2FH]; 645 struct { 646 u_int32_t fhlen; 647 u_int8_t fh[1]; 648 } v3fh; 649 } fh; 650 } *rdata; 651 struct mbuf *m; 652 u_int8_t *fh; 653 int minlen, error; 654 int mntver; 655 656 mntver = (argp->flags & NFSMNT_NFSV3) ? 3 : 2; 657 do { 658 /* 659 * Get port number for MOUNTD. 660 */ 661 error = krpc_portmap(mdsin, RPCPROG_MNT, mntver, 662 IPPROTO_UDP, &mdsin->sin_port); 663 if (error) 664 continue; 665 666 /* This mbuf is consumed by krpc_call. */ 667 m = xdr_string_encode(path, strlen(path)); 668 if (m == NULL) 669 return ENOMEM; 670 671 /* Do RPC to mountd. */ 672 error = krpc_call(mdsin, RPCPROG_MNT, mntver, 673 RPCMNT_MOUNT, &m, NULL); 674 if (error != EPROGMISMATCH) 675 break; 676 /* Try lower version of mountd. */ 677 } while (--mntver >= 1); 678 if (error) { 679 printf("nfs_boot: mountd error=%d\n", error); 680 return error; 681 } 682 if (mntver != 3) 683 argp->flags &= ~NFSMNT_NFSV3; 684 685 /* The reply might have only the errno. */ 686 if (m->m_len < 4) 687 goto bad; 688 /* Have at least errno, so check that. */ 689 rdata = mtod(m, struct rdata *); 690 error = fxdr_unsigned(u_int32_t, rdata->errno); 691 if (error) 692 goto out; 693 694 /* Have errno==0, so the fh must be there. */ 695 if (mntver == 3) { 696 argp->fhsize = fxdr_unsigned(u_int32_t, rdata->fh.v3fh.fhlen); 697 if (argp->fhsize > NFSX_V3FHMAX) 698 goto bad; 699 minlen = 2 * sizeof(u_int32_t) + argp->fhsize; 700 } else { 701 argp->fhsize = NFSX_V2FH; 702 minlen = sizeof(u_int32_t) + argp->fhsize; 703 } 704 705 if (m->m_len < minlen) { 706 m = m_pullup(m, minlen); 707 if (m == NULL) 708 return(EBADRPC); 709 rdata = mtod(m, struct rdata *); 710 } 711 712 fh = (mntver == 3) ? 713 rdata->fh.v3fh.fh : rdata->fh.v2fh; 714 memcpy(argp->fh, fh, argp->fhsize); 715 716 goto out; 717 718 bad: 719 error = EBADRPC; 720 721 out: 722 m_freem(m); 723 return error; 724 } 725