1 /* 2 * $Id: nfsroot.c,v 1.45 1998/03/07 10:44:46 mj Exp $ 3 * 4 * Copyright (C) 1995, 1996 Gero Kuhlmann <gero@gkminix.han.de> 5 * 6 * Allow an NFS filesystem to be mounted as root. The way this works is: 7 * (1) Use the IP autoconfig mechanism to set local IP addresses and routes. 8 * (2) Handle RPC negotiation with the system which replied to RARP or 9 * was reported as a boot server by BOOTP or manually. 10 * (3) The actual mounting is done later, when init() is running. 11 * 12 * 13 * Changes: 14 * 15 * Alan Cox : Removed get_address name clash with FPU. 16 * Alan Cox : Reformatted a bit. 17 * Gero Kuhlmann : Code cleanup 18 * Michael Rausch : Fixed recognition of an incoming RARP answer. 19 * Martin Mares : (2.0) Auto-configuration via BOOTP supported. 20 * Martin Mares : Manual selection of interface & BOOTP/RARP. 21 * Martin Mares : Using network routes instead of host routes, 22 * allowing the default configuration to be used 23 * for normal operation of the host. 24 * Martin Mares : Randomized timer with exponential backoff 25 * installed to minimize network congestion. 26 * Martin Mares : Code cleanup. 27 * Martin Mares : (2.1) BOOTP and RARP made configuration options. 28 * Martin Mares : Server hostname generation fixed. 29 * Gerd Knorr : Fixed wired inode handling 30 * Martin Mares : (2.2) "0.0.0.0" addresses from command line ignored. 31 * Martin Mares : RARP replies not tested for server address. 32 * Gero Kuhlmann : (2.3) Some bug fixes and code cleanup again (please 33 * send me your new patches _before_ bothering 34 * Linus so that I don' always have to cleanup 35 * _afterwards_ - thanks) 36 * Gero Kuhlmann : Last changes of Martin Mares undone. 37 * Gero Kuhlmann : RARP replies are tested for specified server 38 * again. However, it's now possible to have 39 * different RARP and NFS servers. 40 * Gero Kuhlmann : "0.0.0.0" addresses from command line are 41 * now mapped to INADDR_NONE. 42 * Gero Kuhlmann : Fixed a bug which prevented BOOTP path name 43 * from being used (thanks to Leo Spiekman) 44 * Andy Walker : Allow to specify the NFS server in nfs_root 45 * without giving a path name 46 * Swen Th�mmler : Allow to specify the NFS options in nfs_root 47 * without giving a path name. Fix BOOTP request 48 * for domainname (domainname is NIS domain, not 49 * DNS domain!). Skip dummy devices for BOOTP. 50 * Jacek Zapala : Fixed a bug which prevented server-ip address 51 * from nfsroot parameter from being used. 52 * Olaf Kirch : Adapted to new NFS code. 53 * Jakub Jelinek : Free used code segment. 54 * Marko Kohtala : Fixed some bugs. 55 * Martin Mares : Debug message cleanup 56 * Martin Mares : Changed to use the new generic IP layer autoconfig 57 * code. BOOTP and RARP moved there. 58 * Martin Mares : Default path now contains host name instead of 59 * host IP address (but host name defaults to IP 60 * address anyway). 61 * Martin Mares : Use root_server_addr appropriately during setup. 62 * Martin Mares : Rewrote parameter parsing, now hopefully giving 63 * correct overriding. 64 * Trond Myklebust : Add in preliminary support for NFSv3 and TCP. 65 * Fix bug in root_nfs_addr(). nfs_data.namlen 66 * is NOT for the length of the hostname. 67 * Hua Qin : Support for mounting root file system via 68 * NFS over TCP. 69 * Fabian Frederick: Option parser rebuilt (using parser lib) 70 */ 71 72 #include <linux/types.h> 73 #include <linux/string.h> 74 #include <linux/kernel.h> 75 #include <linux/time.h> 76 #include <linux/fs.h> 77 #include <linux/init.h> 78 #include <linux/sunrpc/clnt.h> 79 #include <linux/nfs.h> 80 #include <linux/nfs_fs.h> 81 #include <linux/nfs_mount.h> 82 #include <linux/in.h> 83 #include <linux/major.h> 84 #include <linux/utsname.h> 85 #include <linux/inet.h> 86 #include <linux/root_dev.h> 87 #include <net/ipconfig.h> 88 #include <linux/parser.h> 89 90 /* Define this to allow debugging output */ 91 #undef NFSROOT_DEBUG 92 #define NFSDBG_FACILITY NFSDBG_ROOT 93 94 /* Default path we try to mount. "%s" gets replaced by our IP address */ 95 #define NFS_ROOT "/tftpboot/%s" 96 97 /* Parameters passed from the kernel command line */ 98 static char nfs_root_name[256] __initdata = ""; 99 100 /* Address of NFS server */ 101 static __be32 servaddr __initdata = 0; 102 103 /* Name of directory to mount */ 104 static char nfs_path[NFS_MAXPATHLEN] __initdata = { 0, }; 105 106 /* NFS-related data */ 107 static struct nfs_mount_data nfs_data __initdata = { 0, };/* NFS mount info */ 108 static int nfs_port __initdata = 0; /* Port to connect to for NFS */ 109 static int mount_port __initdata = 0; /* Mount daemon port number */ 110 111 112 /*************************************************************************** 113 114 Parsing of options 115 116 ***************************************************************************/ 117 118 enum { 119 /* Options that take integer arguments */ 120 Opt_port, Opt_rsize, Opt_wsize, Opt_timeo, Opt_retrans, Opt_acregmin, 121 Opt_acregmax, Opt_acdirmin, Opt_acdirmax, 122 /* Options that take no arguments */ 123 Opt_soft, Opt_hard, Opt_intr, 124 Opt_nointr, Opt_posix, Opt_noposix, Opt_cto, Opt_nocto, Opt_ac, 125 Opt_noac, Opt_lock, Opt_nolock, Opt_v2, Opt_v3, Opt_udp, Opt_tcp, 126 Opt_acl, Opt_noacl, 127 /* Error token */ 128 Opt_err 129 }; 130 131 static match_table_t __initdata tokens = { 132 {Opt_port, "port=%u"}, 133 {Opt_rsize, "rsize=%u"}, 134 {Opt_wsize, "wsize=%u"}, 135 {Opt_timeo, "timeo=%u"}, 136 {Opt_retrans, "retrans=%u"}, 137 {Opt_acregmin, "acregmin=%u"}, 138 {Opt_acregmax, "acregmax=%u"}, 139 {Opt_acdirmin, "acdirmin=%u"}, 140 {Opt_acdirmax, "acdirmax=%u"}, 141 {Opt_soft, "soft"}, 142 {Opt_hard, "hard"}, 143 {Opt_intr, "intr"}, 144 {Opt_nointr, "nointr"}, 145 {Opt_posix, "posix"}, 146 {Opt_noposix, "noposix"}, 147 {Opt_cto, "cto"}, 148 {Opt_nocto, "nocto"}, 149 {Opt_ac, "ac"}, 150 {Opt_noac, "noac"}, 151 {Opt_lock, "lock"}, 152 {Opt_nolock, "nolock"}, 153 {Opt_v2, "nfsvers=2"}, 154 {Opt_v2, "v2"}, 155 {Opt_v3, "nfsvers=3"}, 156 {Opt_v3, "v3"}, 157 {Opt_udp, "proto=udp"}, 158 {Opt_udp, "udp"}, 159 {Opt_tcp, "proto=tcp"}, 160 {Opt_tcp, "tcp"}, 161 {Opt_acl, "acl"}, 162 {Opt_noacl, "noacl"}, 163 {Opt_err, NULL} 164 165 }; 166 167 /* 168 * Parse option string. 169 */ 170 171 static int __init root_nfs_parse(char *name, char *buf) 172 { 173 174 char *p; 175 substring_t args[MAX_OPT_ARGS]; 176 int option; 177 178 if (!name) 179 return 1; 180 181 /* Set the NFS remote path */ 182 p = strsep(&name, ","); 183 if (p[0] != '\0' && strcmp(p, "default") != 0) 184 strlcpy(buf, p, NFS_MAXPATHLEN); 185 186 while ((p = strsep (&name, ",")) != NULL) { 187 int token; 188 if (!*p) 189 continue; 190 token = match_token(p, tokens, args); 191 192 /* %u tokens only. Beware if you add new tokens! */ 193 if (token < Opt_soft && match_int(&args[0], &option)) 194 return 0; 195 switch (token) { 196 case Opt_port: 197 nfs_port = option; 198 break; 199 case Opt_rsize: 200 nfs_data.rsize = option; 201 break; 202 case Opt_wsize: 203 nfs_data.wsize = option; 204 break; 205 case Opt_timeo: 206 nfs_data.timeo = option; 207 break; 208 case Opt_retrans: 209 nfs_data.retrans = option; 210 break; 211 case Opt_acregmin: 212 nfs_data.acregmin = option; 213 break; 214 case Opt_acregmax: 215 nfs_data.acregmax = option; 216 break; 217 case Opt_acdirmin: 218 nfs_data.acdirmin = option; 219 break; 220 case Opt_acdirmax: 221 nfs_data.acdirmax = option; 222 break; 223 case Opt_soft: 224 nfs_data.flags |= NFS_MOUNT_SOFT; 225 break; 226 case Opt_hard: 227 nfs_data.flags &= ~NFS_MOUNT_SOFT; 228 break; 229 case Opt_intr: 230 nfs_data.flags |= NFS_MOUNT_INTR; 231 break; 232 case Opt_nointr: 233 nfs_data.flags &= ~NFS_MOUNT_INTR; 234 break; 235 case Opt_posix: 236 nfs_data.flags |= NFS_MOUNT_POSIX; 237 break; 238 case Opt_noposix: 239 nfs_data.flags &= ~NFS_MOUNT_POSIX; 240 break; 241 case Opt_cto: 242 nfs_data.flags &= ~NFS_MOUNT_NOCTO; 243 break; 244 case Opt_nocto: 245 nfs_data.flags |= NFS_MOUNT_NOCTO; 246 break; 247 case Opt_ac: 248 nfs_data.flags &= ~NFS_MOUNT_NOAC; 249 break; 250 case Opt_noac: 251 nfs_data.flags |= NFS_MOUNT_NOAC; 252 break; 253 case Opt_lock: 254 nfs_data.flags &= ~NFS_MOUNT_NONLM; 255 break; 256 case Opt_nolock: 257 nfs_data.flags |= NFS_MOUNT_NONLM; 258 break; 259 case Opt_v2: 260 nfs_data.flags &= ~NFS_MOUNT_VER3; 261 break; 262 case Opt_v3: 263 nfs_data.flags |= NFS_MOUNT_VER3; 264 break; 265 case Opt_udp: 266 nfs_data.flags &= ~NFS_MOUNT_TCP; 267 break; 268 case Opt_tcp: 269 nfs_data.flags |= NFS_MOUNT_TCP; 270 break; 271 case Opt_acl: 272 nfs_data.flags &= ~NFS_MOUNT_NOACL; 273 break; 274 case Opt_noacl: 275 nfs_data.flags |= NFS_MOUNT_NOACL; 276 break; 277 default: 278 printk(KERN_WARNING "Root-NFS: unknown " 279 "option: %s\n", p); 280 return 0; 281 } 282 } 283 284 return 1; 285 } 286 287 /* 288 * Prepare the NFS data structure and parse all options. 289 */ 290 static int __init root_nfs_name(char *name) 291 { 292 static char buf[NFS_MAXPATHLEN] __initdata; 293 char *cp; 294 295 /* Set some default values */ 296 memset(&nfs_data, 0, sizeof(nfs_data)); 297 nfs_port = -1; 298 nfs_data.version = NFS_MOUNT_VERSION; 299 nfs_data.flags = NFS_MOUNT_NONLM; /* No lockd in nfs root yet */ 300 nfs_data.rsize = NFS_DEF_FILE_IO_SIZE; 301 nfs_data.wsize = NFS_DEF_FILE_IO_SIZE; 302 nfs_data.acregmin = 3; 303 nfs_data.acregmax = 60; 304 nfs_data.acdirmin = 30; 305 nfs_data.acdirmax = 60; 306 strcpy(buf, NFS_ROOT); 307 308 /* Process options received from the remote server */ 309 root_nfs_parse(root_server_path, buf); 310 311 /* Override them by options set on kernel command-line */ 312 root_nfs_parse(name, buf); 313 314 cp = utsname()->nodename; 315 if (strlen(buf) + strlen(cp) > NFS_MAXPATHLEN) { 316 printk(KERN_ERR "Root-NFS: Pathname for remote directory too long.\n"); 317 return -1; 318 } 319 sprintf(nfs_path, buf, cp); 320 321 return 1; 322 } 323 324 325 /* 326 * Get NFS server address. 327 */ 328 static int __init root_nfs_addr(void) 329 { 330 if ((servaddr = root_server_addr) == htonl(INADDR_NONE)) { 331 printk(KERN_ERR "Root-NFS: No NFS server available, giving up.\n"); 332 return -1; 333 } 334 335 snprintf(nfs_data.hostname, sizeof(nfs_data.hostname), 336 "%u.%u.%u.%u", NIPQUAD(servaddr)); 337 return 0; 338 } 339 340 /* 341 * Tell the user what's going on. 342 */ 343 #ifdef NFSROOT_DEBUG 344 static void __init root_nfs_print(void) 345 { 346 printk(KERN_NOTICE "Root-NFS: Mounting %s on server %s as root\n", 347 nfs_path, nfs_data.hostname); 348 printk(KERN_NOTICE "Root-NFS: rsize = %d, wsize = %d, timeo = %d, retrans = %d\n", 349 nfs_data.rsize, nfs_data.wsize, nfs_data.timeo, nfs_data.retrans); 350 printk(KERN_NOTICE "Root-NFS: acreg (min,max) = (%d,%d), acdir (min,max) = (%d,%d)\n", 351 nfs_data.acregmin, nfs_data.acregmax, 352 nfs_data.acdirmin, nfs_data.acdirmax); 353 printk(KERN_NOTICE "Root-NFS: nfsd port = %d, mountd port = %d, flags = %08x\n", 354 nfs_port, mount_port, nfs_data.flags); 355 } 356 #endif 357 358 359 static int __init root_nfs_init(void) 360 { 361 #ifdef NFSROOT_DEBUG 362 nfs_debug |= NFSDBG_ROOT; 363 #endif 364 365 /* 366 * Decode the root directory path name and NFS options from 367 * the kernel command line. This has to go here in order to 368 * be able to use the client IP address for the remote root 369 * directory (necessary for pure RARP booting). 370 */ 371 if (root_nfs_name(nfs_root_name) < 0 || 372 root_nfs_addr() < 0) 373 return -1; 374 375 #ifdef NFSROOT_DEBUG 376 root_nfs_print(); 377 #endif 378 379 return 0; 380 } 381 382 383 /* 384 * Parse NFS server and directory information passed on the kernel 385 * command line. 386 */ 387 static int __init nfs_root_setup(char *line) 388 { 389 ROOT_DEV = Root_NFS; 390 if (line[0] == '/' || line[0] == ',' || (line[0] >= '0' && line[0] <= '9')) { 391 strlcpy(nfs_root_name, line, sizeof(nfs_root_name)); 392 } else { 393 int n = strlen(line) + sizeof(NFS_ROOT) - 1; 394 if (n >= sizeof(nfs_root_name)) 395 line[sizeof(nfs_root_name) - sizeof(NFS_ROOT) - 2] = '\0'; 396 sprintf(nfs_root_name, NFS_ROOT, line); 397 } 398 root_server_addr = root_nfs_parse_addr(nfs_root_name); 399 return 1; 400 } 401 402 __setup("nfsroot=", nfs_root_setup); 403 404 /*************************************************************************** 405 406 Routines to actually mount the root directory 407 408 ***************************************************************************/ 409 410 /* 411 * Construct sockaddr_in from address and port number. 412 */ 413 static inline void 414 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port) 415 { 416 sin->sin_family = AF_INET; 417 sin->sin_addr.s_addr = addr; 418 sin->sin_port = port; 419 } 420 421 /* 422 * Query server portmapper for the port of a daemon program. 423 */ 424 static int __init root_nfs_getport(int program, int version, int proto) 425 { 426 struct sockaddr_in sin; 427 428 printk(KERN_NOTICE "Looking up port of RPC %d/%d on %u.%u.%u.%u\n", 429 program, version, NIPQUAD(servaddr)); 430 set_sockaddr(&sin, servaddr, 0); 431 return rpcb_getport_external(&sin, program, version, proto); 432 } 433 434 435 /* 436 * Use portmapper to find mountd and nfsd port numbers if not overriden 437 * by the user. Use defaults if portmapper is not available. 438 * XXX: Is there any nfs server with no portmapper? 439 */ 440 static int __init root_nfs_ports(void) 441 { 442 int port; 443 int nfsd_ver, mountd_ver; 444 int nfsd_port, mountd_port; 445 int proto; 446 447 if (nfs_data.flags & NFS_MOUNT_VER3) { 448 nfsd_ver = NFS3_VERSION; 449 mountd_ver = NFS_MNT3_VERSION; 450 nfsd_port = NFS_PORT; 451 mountd_port = NFS_MNT_PORT; 452 } else { 453 nfsd_ver = NFS2_VERSION; 454 mountd_ver = NFS_MNT_VERSION; 455 nfsd_port = NFS_PORT; 456 mountd_port = NFS_MNT_PORT; 457 } 458 459 proto = (nfs_data.flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP; 460 461 if (nfs_port < 0) { 462 if ((port = root_nfs_getport(NFS_PROGRAM, nfsd_ver, proto)) < 0) { 463 printk(KERN_ERR "Root-NFS: Unable to get nfsd port " 464 "number from server, using default\n"); 465 port = nfsd_port; 466 } 467 nfs_port = port; 468 dprintk("Root-NFS: Portmapper on server returned %d " 469 "as nfsd port\n", port); 470 } 471 472 if ((port = root_nfs_getport(NFS_MNT_PROGRAM, mountd_ver, proto)) < 0) { 473 printk(KERN_ERR "Root-NFS: Unable to get mountd port " 474 "number from server, using default\n"); 475 port = mountd_port; 476 } 477 mount_port = port; 478 dprintk("Root-NFS: mountd port is %d\n", port); 479 480 return 0; 481 } 482 483 484 /* 485 * Get a file handle from the server for the directory which is to be 486 * mounted. 487 */ 488 static int __init root_nfs_get_handle(void) 489 { 490 struct nfs_fh fh; 491 struct sockaddr_in sin; 492 int status; 493 int protocol = (nfs_data.flags & NFS_MOUNT_TCP) ? 494 IPPROTO_TCP : IPPROTO_UDP; 495 int version = (nfs_data.flags & NFS_MOUNT_VER3) ? 496 NFS_MNT3_VERSION : NFS_MNT_VERSION; 497 498 set_sockaddr(&sin, servaddr, htons(mount_port)); 499 status = nfsroot_mount(&sin, nfs_path, &fh, version, protocol); 500 if (status < 0) 501 printk(KERN_ERR "Root-NFS: Server returned error %d " 502 "while mounting %s\n", status, nfs_path); 503 else { 504 nfs_data.root.size = fh.size; 505 memcpy(nfs_data.root.data, fh.data, fh.size); 506 } 507 508 return status; 509 } 510 511 /* 512 * Get the NFS port numbers and file handle, and return the prepared 'data' 513 * argument for mount() if everything went OK. Return NULL otherwise. 514 */ 515 void * __init nfs_root_data(void) 516 { 517 if (root_nfs_init() < 0 518 || root_nfs_ports() < 0 519 || root_nfs_get_handle() < 0) 520 return NULL; 521 set_sockaddr((struct sockaddr_in *) &nfs_data.addr, servaddr, htons(nfs_port)); 522 return (void*)&nfs_data; 523 } 524