1/* 2 * Copyright (C) 1995, 1996 Gero Kuhlmann <gero@gkminix.han.de> 3 * 4 * Allow an NFS filesystem to be mounted as root. The way this works is: 5 * (1) Use the IP autoconfig mechanism to set local IP addresses and routes. 6 * (2) Handle RPC negotiation with the system which replied to RARP or 7 * was reported as a boot server by BOOTP or manually. 8 * (3) The actual mounting is done later, when init() is running. 9 * 10 * 11 * Changes: 12 * 13 * Alan Cox : Removed get_address name clash with FPU. 14 * Alan Cox : Reformatted a bit. 15 * Gero Kuhlmann : Code cleanup 16 * Michael Rausch : Fixed recognition of an incoming RARP answer. 17 * Martin Mares : (2.0) Auto-configuration via BOOTP supported. 18 * Martin Mares : Manual selection of interface & BOOTP/RARP. 19 * Martin Mares : Using network routes instead of host routes, 20 * allowing the default configuration to be used 21 * for normal operation of the host. 22 * Martin Mares : Randomized timer with exponential backoff 23 * installed to minimize network congestion. 24 * Martin Mares : Code cleanup. 25 * Martin Mares : (2.1) BOOTP and RARP made configuration options. 26 * Martin Mares : Server hostname generation fixed. 27 * Gerd Knorr : Fixed wired inode handling 28 * Martin Mares : (2.2) "0.0.0.0" addresses from command line ignored. 29 * Martin Mares : RARP replies not tested for server address. 30 * Gero Kuhlmann : (2.3) Some bug fixes and code cleanup again (please 31 * send me your new patches _before_ bothering 32 * Linus so that I don' always have to cleanup 33 * _afterwards_ - thanks) 34 * Gero Kuhlmann : Last changes of Martin Mares undone. 35 * Gero Kuhlmann : RARP replies are tested for specified server 36 * again. However, it's now possible to have 37 * different RARP and NFS servers. 38 * Gero Kuhlmann : "0.0.0.0" addresses from command line are 39 * now mapped to INADDR_NONE. 40 * Gero Kuhlmann : Fixed a bug which prevented BOOTP path name 41 * from being used (thanks to Leo Spiekman) 42 * Andy Walker : Allow to specify the NFS server in nfs_root 43 * without giving a path name 44 * Swen Th��mmler : Allow to specify the NFS options in nfs_root 45 * without giving a path name. Fix BOOTP request 46 * for domainname (domainname is NIS domain, not 47 * DNS domain!). Skip dummy devices for BOOTP. 48 * Jacek Zapala : Fixed a bug which prevented server-ip address 49 * from nfsroot parameter from being used. 50 * Olaf Kirch : Adapted to new NFS code. 51 * Jakub Jelinek : Free used code segment. 52 * Marko Kohtala : Fixed some bugs. 53 * Martin Mares : Debug message cleanup 54 * Martin Mares : Changed to use the new generic IP layer autoconfig 55 * code. BOOTP and RARP moved there. 56 * Martin Mares : Default path now contains host name instead of 57 * host IP address (but host name defaults to IP 58 * address anyway). 59 * Martin Mares : Use root_server_addr appropriately during setup. 60 * Martin Mares : Rewrote parameter parsing, now hopefully giving 61 * correct overriding. 62 * Trond Myklebust : Add in preliminary support for NFSv3 and TCP. 63 * Fix bug in root_nfs_addr(). nfs_data.namlen 64 * is NOT for the length of the hostname. 65 * Hua Qin : Support for mounting root file system via 66 * NFS over TCP. 67 * Fabian Frederick: Option parser rebuilt (using parser lib) 68*/ 69 70#include <linux/types.h> 71#include <linux/string.h> 72#include <linux/kernel.h> 73#include <linux/time.h> 74#include <linux/fs.h> 75#include <linux/init.h> 76#include <linux/sunrpc/clnt.h> 77#include <linux/sunrpc/xprtsock.h> 78#include <linux/nfs.h> 79#include <linux/nfs_fs.h> 80#include <linux/nfs_mount.h> 81#include <linux/in.h> 82#include <linux/major.h> 83#include <linux/utsname.h> 84#include <linux/inet.h> 85#include <linux/root_dev.h> 86#include <net/ipconfig.h> 87#include <linux/parser.h> 88 89#include "internal.h" 90 91/* Define this to allow debugging output */ 92#undef NFSROOT_DEBUG 93#define NFSDBG_FACILITY NFSDBG_ROOT 94 95/* Default port to use if server is not running a portmapper */ 96#define NFS_MNT_PORT 627 97 98/* Default path we try to mount. "%s" gets replaced by our IP address */ 99#define NFS_ROOT "/tftpboot/%s" 100 101/* Parameters passed from the kernel command line */ 102static char nfs_root_name[256] __initdata = ""; 103 104/* Address of NFS server */ 105static __be32 servaddr __initdata = 0; 106 107/* Name of directory to mount */ 108static char nfs_export_path[NFS_MAXPATHLEN + 1] __initdata = { 0, }; 109 110/* NFS-related data */ 111static struct nfs_mount_data nfs_data __initdata = { 0, };/* NFS mount info */ 112static int nfs_port __initdata = 0; /* Port to connect to for NFS */ 113static int mount_port __initdata = 0; /* Mount daemon port number */ 114 115 116/*************************************************************************** 117 118 Parsing of options 119 120 ***************************************************************************/ 121 122enum { 123 /* Options that take integer arguments */ 124 Opt_port, Opt_rsize, Opt_wsize, Opt_timeo, Opt_retrans, Opt_acregmin, 125 Opt_acregmax, Opt_acdirmin, Opt_acdirmax, 126 /* Options that take no arguments */ 127 Opt_soft, Opt_hard, Opt_intr, 128 Opt_nointr, Opt_posix, Opt_noposix, Opt_cto, Opt_nocto, Opt_ac, 129 Opt_noac, Opt_lock, Opt_nolock, Opt_v2, Opt_v3, Opt_udp, Opt_tcp, 130 Opt_acl, Opt_noacl, 131 /* Error token */ 132 Opt_err 133}; 134 135static const match_table_t tokens __initconst = { 136 {Opt_port, "port=%u"}, 137 {Opt_rsize, "rsize=%u"}, 138 {Opt_wsize, "wsize=%u"}, 139 {Opt_timeo, "timeo=%u"}, 140 {Opt_retrans, "retrans=%u"}, 141 {Opt_acregmin, "acregmin=%u"}, 142 {Opt_acregmax, "acregmax=%u"}, 143 {Opt_acdirmin, "acdirmin=%u"}, 144 {Opt_acdirmax, "acdirmax=%u"}, 145 {Opt_soft, "soft"}, 146 {Opt_hard, "hard"}, 147 {Opt_intr, "intr"}, 148 {Opt_nointr, "nointr"}, 149 {Opt_posix, "posix"}, 150 {Opt_noposix, "noposix"}, 151 {Opt_cto, "cto"}, 152 {Opt_nocto, "nocto"}, 153 {Opt_ac, "ac"}, 154 {Opt_noac, "noac"}, 155 {Opt_lock, "lock"}, 156 {Opt_nolock, "nolock"}, 157 {Opt_v2, "nfsvers=2"}, 158 {Opt_v2, "v2"}, 159 {Opt_v3, "nfsvers=3"}, 160 {Opt_v3, "v3"}, 161 {Opt_udp, "proto=udp"}, 162 {Opt_udp, "udp"}, 163 {Opt_tcp, "proto=tcp"}, 164 {Opt_tcp, "tcp"}, 165 {Opt_acl, "acl"}, 166 {Opt_noacl, "noacl"}, 167 {Opt_err, NULL} 168 169}; 170 171/* 172 * Parse option string. 173 */ 174 175static int __init root_nfs_parse(char *name, char *buf) 176{ 177 178 char *p; 179 substring_t args[MAX_OPT_ARGS]; 180 int option; 181 182 if (!name) 183 return 1; 184 185 /* Set the NFS remote path */ 186 p = strsep(&name, ","); 187 if (p[0] != '\0' && strcmp(p, "default") != 0) 188 strlcpy(buf, p, NFS_MAXPATHLEN); 189 190 while ((p = strsep (&name, ",")) != NULL) { 191 int token; 192 if (!*p) 193 continue; 194 token = match_token(p, tokens, args); 195 196 /* %u tokens only. Beware if you add new tokens! */ 197 if (token < Opt_soft && match_int(&args[0], &option)) 198 return 0; 199 switch (token) { 200 case Opt_port: 201 nfs_port = option; 202 break; 203 case Opt_rsize: 204 nfs_data.rsize = option; 205 break; 206 case Opt_wsize: 207 nfs_data.wsize = option; 208 break; 209 case Opt_timeo: 210 nfs_data.timeo = option; 211 break; 212 case Opt_retrans: 213 nfs_data.retrans = option; 214 break; 215 case Opt_acregmin: 216 nfs_data.acregmin = option; 217 break; 218 case Opt_acregmax: 219 nfs_data.acregmax = option; 220 break; 221 case Opt_acdirmin: 222 nfs_data.acdirmin = option; 223 break; 224 case Opt_acdirmax: 225 nfs_data.acdirmax = option; 226 break; 227 case Opt_soft: 228 nfs_data.flags |= NFS_MOUNT_SOFT; 229 break; 230 case Opt_hard: 231 nfs_data.flags &= ~NFS_MOUNT_SOFT; 232 break; 233 case Opt_intr: 234 case Opt_nointr: 235 break; 236 case Opt_posix: 237 nfs_data.flags |= NFS_MOUNT_POSIX; 238 break; 239 case Opt_noposix: 240 nfs_data.flags &= ~NFS_MOUNT_POSIX; 241 break; 242 case Opt_cto: 243 nfs_data.flags &= ~NFS_MOUNT_NOCTO; 244 break; 245 case Opt_nocto: 246 nfs_data.flags |= NFS_MOUNT_NOCTO; 247 break; 248 case Opt_ac: 249 nfs_data.flags &= ~NFS_MOUNT_NOAC; 250 break; 251 case Opt_noac: 252 nfs_data.flags |= NFS_MOUNT_NOAC; 253 break; 254 case Opt_lock: 255 nfs_data.flags &= ~NFS_MOUNT_NONLM; 256 break; 257 case Opt_nolock: 258 nfs_data.flags |= NFS_MOUNT_NONLM; 259 break; 260 case Opt_v2: 261 nfs_data.flags &= ~NFS_MOUNT_VER3; 262 break; 263 case Opt_v3: 264 nfs_data.flags |= NFS_MOUNT_VER3; 265 break; 266 case Opt_udp: 267 nfs_data.flags &= ~NFS_MOUNT_TCP; 268 break; 269 case Opt_tcp: 270 nfs_data.flags |= NFS_MOUNT_TCP; 271 break; 272 case Opt_acl: 273 nfs_data.flags &= ~NFS_MOUNT_NOACL; 274 break; 275 case Opt_noacl: 276 nfs_data.flags |= NFS_MOUNT_NOACL; 277 break; 278 default: 279 printk(KERN_WARNING "Root-NFS: unknown " 280 "option: %s\n", p); 281 return 0; 282 } 283 } 284 285 return 1; 286} 287 288/* 289 * Prepare the NFS data structure and parse all options. 290 */ 291static int __init root_nfs_name(char *name) 292{ 293 static char buf[NFS_MAXPATHLEN] __initdata; 294 char *cp; 295 296 /* Set some default values */ 297 memset(&nfs_data, 0, sizeof(nfs_data)); 298 nfs_port = -1; 299 nfs_data.version = NFS_MOUNT_VERSION; 300 nfs_data.flags = NFS_MOUNT_NONLM; /* No lockd in nfs root yet */ 301 nfs_data.rsize = NFS_DEF_FILE_IO_SIZE; 302 nfs_data.wsize = NFS_DEF_FILE_IO_SIZE; 303 nfs_data.acregmin = NFS_DEF_ACREGMIN; 304 nfs_data.acregmax = NFS_DEF_ACREGMAX; 305 nfs_data.acdirmin = NFS_DEF_ACDIRMIN; 306 nfs_data.acdirmax = NFS_DEF_ACDIRMAX; 307 strcpy(buf, NFS_ROOT); 308 309 /* Process options received from the remote server */ 310 root_nfs_parse(root_server_path, buf); 311 312 /* Override them by options set on kernel command-line */ 313 root_nfs_parse(name, buf); 314 315 cp = utsname()->nodename; 316 if (strlen(buf) + strlen(cp) > NFS_MAXPATHLEN) { 317 printk(KERN_ERR "Root-NFS: Pathname for remote directory too long.\n"); 318 return -1; 319 } 320 sprintf(nfs_export_path, buf, cp); 321 322 return 1; 323} 324 325 326/* 327 * Get NFS server address. 328 */ 329static int __init root_nfs_addr(void) 330{ 331 if ((servaddr = root_server_addr) == htonl(INADDR_NONE)) { 332 printk(KERN_ERR "Root-NFS: No NFS server available, giving up.\n"); 333 return -1; 334 } 335 336 snprintf(nfs_data.hostname, sizeof(nfs_data.hostname), 337 "%pI4", &servaddr); 338 return 0; 339} 340 341/* 342 * Tell the user what's going on. 343 */ 344#ifdef NFSROOT_DEBUG 345static void __init root_nfs_print(void) 346{ 347 printk(KERN_NOTICE "Root-NFS: Mounting %s on server %s as root\n", 348 nfs_export_path, nfs_data.hostname); 349 printk(KERN_NOTICE "Root-NFS: rsize = %d, wsize = %d, timeo = %d, retrans = %d\n", 350 nfs_data.rsize, nfs_data.wsize, nfs_data.timeo, nfs_data.retrans); 351 printk(KERN_NOTICE "Root-NFS: acreg (min,max) = (%d,%d), acdir (min,max) = (%d,%d)\n", 352 nfs_data.acregmin, nfs_data.acregmax, 353 nfs_data.acdirmin, nfs_data.acdirmax); 354 printk(KERN_NOTICE "Root-NFS: nfsd port = %d, mountd port = %d, flags = %08x\n", 355 nfs_port, mount_port, nfs_data.flags); 356} 357#endif 358 359 360static int __init root_nfs_init(void) 361{ 362#ifdef NFSROOT_DEBUG 363 nfs_debug |= NFSDBG_ROOT; 364#endif 365 366 /* 367 * Decode the root directory path name and NFS options from 368 * the kernel command line. This has to go here in order to 369 * be able to use the client IP address for the remote root 370 * directory (necessary for pure RARP booting). 371 */ 372 if (root_nfs_name(nfs_root_name) < 0 || 373 root_nfs_addr() < 0) 374 return -1; 375 376#ifdef NFSROOT_DEBUG 377 root_nfs_print(); 378#endif 379 380 return 0; 381} 382 383 384/* 385 * Parse NFS server and directory information passed on the kernel 386 * command line. 387 */ 388static int __init nfs_root_setup(char *line) 389{ 390 ROOT_DEV = Root_NFS; 391 if (line[0] == '/' || line[0] == ',' || (line[0] >= '0' && line[0] <= '9')) { 392 strlcpy(nfs_root_name, line, sizeof(nfs_root_name)); 393 } else { 394 int n = strlen(line) + sizeof(NFS_ROOT) - 1; 395 if (n >= sizeof(nfs_root_name)) 396 line[sizeof(nfs_root_name) - sizeof(NFS_ROOT) - 2] = '\0'; 397 sprintf(nfs_root_name, NFS_ROOT, line); 398 } 399 root_server_addr = root_nfs_parse_addr(nfs_root_name); 400 return 1; 401} 402 403__setup("nfsroot=", nfs_root_setup); 404 405/*************************************************************************** 406 407 Routines to actually mount the root directory 408 409 ***************************************************************************/ 410 411/* 412 * Construct sockaddr_in from address and port number. 413 */ 414static inline void 415set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port) 416{ 417 sin->sin_family = AF_INET; 418 sin->sin_addr.s_addr = addr; 419 sin->sin_port = port; 420} 421 422/* 423 * Query server portmapper for the port of a daemon program. 424 */ 425static int __init root_nfs_getport(int program, int version, int proto) 426{ 427 struct sockaddr_in sin; 428 429 printk(KERN_NOTICE "Looking up port of RPC %d/%d on %pI4\n", 430 program, version, &servaddr); 431 set_sockaddr(&sin, servaddr, 0); 432 return rpcb_getport_sync(&sin, program, version, proto); 433} 434 435 436static int __init root_nfs_ports(void) 437{ 438 int port; 439 int nfsd_ver, mountd_ver; 440 int nfsd_port, mountd_port; 441 int proto; 442 443 if (nfs_data.flags & NFS_MOUNT_VER3) { 444 nfsd_ver = NFS3_VERSION; 445 mountd_ver = NFS_MNT3_VERSION; 446 nfsd_port = NFS_PORT; 447 mountd_port = NFS_MNT_PORT; 448 } else { 449 nfsd_ver = NFS2_VERSION; 450 mountd_ver = NFS_MNT_VERSION; 451 nfsd_port = NFS_PORT; 452 mountd_port = NFS_MNT_PORT; 453 } 454 455 proto = (nfs_data.flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP; 456 457 if (nfs_port < 0) { 458 if ((port = root_nfs_getport(NFS_PROGRAM, nfsd_ver, proto)) < 0) { 459 printk(KERN_ERR "Root-NFS: Unable to get nfsd port " 460 "number from server, using default\n"); 461 port = nfsd_port; 462 } 463 nfs_port = port; 464 dprintk("Root-NFS: Portmapper on server returned %d " 465 "as nfsd port\n", port); 466 } 467 468 if ((port = root_nfs_getport(NFS_MNT_PROGRAM, mountd_ver, proto)) < 0) { 469 printk(KERN_ERR "Root-NFS: Unable to get mountd port " 470 "number from server, using default\n"); 471 port = mountd_port; 472 } 473 mount_port = port; 474 dprintk("Root-NFS: mountd port is %d\n", port); 475 476 return 0; 477} 478 479 480/* 481 * Get a file handle from the server for the directory which is to be 482 * mounted. 483 */ 484static int __init root_nfs_get_handle(void) 485{ 486 struct sockaddr_in sin; 487 unsigned int auth_flav_len = 0; 488 struct nfs_mount_request request = { 489 .sap = (struct sockaddr *)&sin, 490 .salen = sizeof(sin), 491 .dirpath = nfs_export_path, 492 .version = (nfs_data.flags & NFS_MOUNT_VER3) ? 493 NFS_MNT3_VERSION : NFS_MNT_VERSION, 494 .protocol = (nfs_data.flags & NFS_MOUNT_TCP) ? 495 XPRT_TRANSPORT_TCP : XPRT_TRANSPORT_UDP, 496 .auth_flav_len = &auth_flav_len, 497 }; 498 int status = -ENOMEM; 499 500 request.fh = nfs_alloc_fhandle(); 501 if (!request.fh) 502 goto out; 503 set_sockaddr(&sin, servaddr, htons(mount_port)); 504 status = nfs_mount(&request); 505 if (status < 0) 506 printk(KERN_ERR "Root-NFS: Server returned error %d " 507 "while mounting %s\n", status, nfs_export_path); 508 else { 509 nfs_data.root.size = request.fh->size; 510 memcpy(&nfs_data.root.data, request.fh->data, request.fh->size); 511 } 512 nfs_free_fhandle(request.fh); 513out: 514 return status; 515} 516 517/* 518 * Get the NFS port numbers and file handle, and return the prepared 'data' 519 * argument for mount() if everything went OK. Return NULL otherwise. 520 */ 521void * __init nfs_root_data(void) 522{ 523 if (root_nfs_init() < 0 524 || root_nfs_ports() < 0 525 || root_nfs_get_handle() < 0) 526 return NULL; 527 set_sockaddr((struct sockaddr_in *) &nfs_data.addr, servaddr, htons(nfs_port)); 528 return (void*)&nfs_data; 529} 530