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 Thümmler : 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 /* Define this to allow debugging output */ 90 #undef NFSROOT_DEBUG 91 #define NFSDBG_FACILITY NFSDBG_ROOT 92 93 /* Default path we try to mount. "%s" gets replaced by our IP address */ 94 #define NFS_ROOT "/tftpboot/%s" 95 96 /* Parameters passed from the kernel command line */ 97 static char nfs_root_name[256] __initdata = ""; 98 99 /* Address of NFS server */ 100 static __be32 servaddr __initdata = 0; 101 102 /* Name of directory to mount */ 103 static char nfs_path[NFS_MAXPATHLEN] __initdata = { 0, }; 104 105 /* NFS-related data */ 106 static struct nfs_mount_data nfs_data __initdata = { 0, };/* NFS mount info */ 107 static int nfs_port __initdata = 0; /* Port to connect to for NFS */ 108 static int mount_port __initdata = 0; /* Mount daemon port number */ 109 110 111 /*************************************************************************** 112 113 Parsing of options 114 115 ***************************************************************************/ 116 117 enum { 118 /* Options that take integer arguments */ 119 Opt_port, Opt_rsize, Opt_wsize, Opt_timeo, Opt_retrans, Opt_acregmin, 120 Opt_acregmax, Opt_acdirmin, Opt_acdirmax, 121 /* Options that take no arguments */ 122 Opt_soft, Opt_hard, Opt_intr, 123 Opt_nointr, Opt_posix, Opt_noposix, Opt_cto, Opt_nocto, Opt_ac, 124 Opt_noac, Opt_lock, Opt_nolock, Opt_v2, Opt_v3, Opt_udp, Opt_tcp, 125 Opt_acl, Opt_noacl, 126 /* Error token */ 127 Opt_err 128 }; 129 130 static match_table_t __initconst tokens = { 131 {Opt_port, "port=%u"}, 132 {Opt_rsize, "rsize=%u"}, 133 {Opt_wsize, "wsize=%u"}, 134 {Opt_timeo, "timeo=%u"}, 135 {Opt_retrans, "retrans=%u"}, 136 {Opt_acregmin, "acregmin=%u"}, 137 {Opt_acregmax, "acregmax=%u"}, 138 {Opt_acdirmin, "acdirmin=%u"}, 139 {Opt_acdirmax, "acdirmax=%u"}, 140 {Opt_soft, "soft"}, 141 {Opt_hard, "hard"}, 142 {Opt_intr, "intr"}, 143 {Opt_nointr, "nointr"}, 144 {Opt_posix, "posix"}, 145 {Opt_noposix, "noposix"}, 146 {Opt_cto, "cto"}, 147 {Opt_nocto, "nocto"}, 148 {Opt_ac, "ac"}, 149 {Opt_noac, "noac"}, 150 {Opt_lock, "lock"}, 151 {Opt_nolock, "nolock"}, 152 {Opt_v2, "nfsvers=2"}, 153 {Opt_v2, "v2"}, 154 {Opt_v3, "nfsvers=3"}, 155 {Opt_v3, "v3"}, 156 {Opt_udp, "proto=udp"}, 157 {Opt_udp, "udp"}, 158 {Opt_tcp, "proto=tcp"}, 159 {Opt_tcp, "tcp"}, 160 {Opt_acl, "acl"}, 161 {Opt_noacl, "noacl"}, 162 {Opt_err, NULL} 163 164 }; 165 166 /* 167 * Parse option string. 168 */ 169 170 static int __init root_nfs_parse(char *name, char *buf) 171 { 172 173 char *p; 174 substring_t args[MAX_OPT_ARGS]; 175 int option; 176 177 if (!name) 178 return 1; 179 180 /* Set the NFS remote path */ 181 p = strsep(&name, ","); 182 if (p[0] != '\0' && strcmp(p, "default") != 0) 183 strlcpy(buf, p, NFS_MAXPATHLEN); 184 185 while ((p = strsep (&name, ",")) != NULL) { 186 int token; 187 if (!*p) 188 continue; 189 token = match_token(p, tokens, args); 190 191 /* %u tokens only. Beware if you add new tokens! */ 192 if (token < Opt_soft && match_int(&args[0], &option)) 193 return 0; 194 switch (token) { 195 case Opt_port: 196 nfs_port = option; 197 break; 198 case Opt_rsize: 199 nfs_data.rsize = option; 200 break; 201 case Opt_wsize: 202 nfs_data.wsize = option; 203 break; 204 case Opt_timeo: 205 nfs_data.timeo = option; 206 break; 207 case Opt_retrans: 208 nfs_data.retrans = option; 209 break; 210 case Opt_acregmin: 211 nfs_data.acregmin = option; 212 break; 213 case Opt_acregmax: 214 nfs_data.acregmax = option; 215 break; 216 case Opt_acdirmin: 217 nfs_data.acdirmin = option; 218 break; 219 case Opt_acdirmax: 220 nfs_data.acdirmax = option; 221 break; 222 case Opt_soft: 223 nfs_data.flags |= NFS_MOUNT_SOFT; 224 break; 225 case Opt_hard: 226 nfs_data.flags &= ~NFS_MOUNT_SOFT; 227 break; 228 case Opt_intr: 229 case Opt_nointr: 230 break; 231 case Opt_posix: 232 nfs_data.flags |= NFS_MOUNT_POSIX; 233 break; 234 case Opt_noposix: 235 nfs_data.flags &= ~NFS_MOUNT_POSIX; 236 break; 237 case Opt_cto: 238 nfs_data.flags &= ~NFS_MOUNT_NOCTO; 239 break; 240 case Opt_nocto: 241 nfs_data.flags |= NFS_MOUNT_NOCTO; 242 break; 243 case Opt_ac: 244 nfs_data.flags &= ~NFS_MOUNT_NOAC; 245 break; 246 case Opt_noac: 247 nfs_data.flags |= NFS_MOUNT_NOAC; 248 break; 249 case Opt_lock: 250 nfs_data.flags &= ~NFS_MOUNT_NONLM; 251 break; 252 case Opt_nolock: 253 nfs_data.flags |= NFS_MOUNT_NONLM; 254 break; 255 case Opt_v2: 256 nfs_data.flags &= ~NFS_MOUNT_VER3; 257 break; 258 case Opt_v3: 259 nfs_data.flags |= NFS_MOUNT_VER3; 260 break; 261 case Opt_udp: 262 nfs_data.flags &= ~NFS_MOUNT_TCP; 263 break; 264 case Opt_tcp: 265 nfs_data.flags |= NFS_MOUNT_TCP; 266 break; 267 case Opt_acl: 268 nfs_data.flags &= ~NFS_MOUNT_NOACL; 269 break; 270 case Opt_noacl: 271 nfs_data.flags |= NFS_MOUNT_NOACL; 272 break; 273 default: 274 printk(KERN_WARNING "Root-NFS: unknown " 275 "option: %s\n", p); 276 return 0; 277 } 278 } 279 280 return 1; 281 } 282 283 /* 284 * Prepare the NFS data structure and parse all options. 285 */ 286 static int __init root_nfs_name(char *name) 287 { 288 static char buf[NFS_MAXPATHLEN] __initdata; 289 char *cp; 290 291 /* Set some default values */ 292 memset(&nfs_data, 0, sizeof(nfs_data)); 293 nfs_port = -1; 294 nfs_data.version = NFS_MOUNT_VERSION; 295 nfs_data.flags = NFS_MOUNT_NONLM; /* No lockd in nfs root yet */ 296 nfs_data.rsize = NFS_DEF_FILE_IO_SIZE; 297 nfs_data.wsize = NFS_DEF_FILE_IO_SIZE; 298 nfs_data.acregmin = NFS_DEF_ACREGMIN; 299 nfs_data.acregmax = NFS_DEF_ACREGMAX; 300 nfs_data.acdirmin = NFS_DEF_ACDIRMIN; 301 nfs_data.acdirmax = NFS_DEF_ACDIRMAX; 302 strcpy(buf, NFS_ROOT); 303 304 /* Process options received from the remote server */ 305 root_nfs_parse(root_server_path, buf); 306 307 /* Override them by options set on kernel command-line */ 308 root_nfs_parse(name, buf); 309 310 cp = utsname()->nodename; 311 if (strlen(buf) + strlen(cp) > NFS_MAXPATHLEN) { 312 printk(KERN_ERR "Root-NFS: Pathname for remote directory too long.\n"); 313 return -1; 314 } 315 sprintf(nfs_path, buf, cp); 316 317 return 1; 318 } 319 320 321 /* 322 * Get NFS server address. 323 */ 324 static int __init root_nfs_addr(void) 325 { 326 if ((servaddr = root_server_addr) == htonl(INADDR_NONE)) { 327 printk(KERN_ERR "Root-NFS: No NFS server available, giving up.\n"); 328 return -1; 329 } 330 331 snprintf(nfs_data.hostname, sizeof(nfs_data.hostname), 332 "%u.%u.%u.%u", NIPQUAD(servaddr)); 333 return 0; 334 } 335 336 /* 337 * Tell the user what's going on. 338 */ 339 #ifdef NFSROOT_DEBUG 340 static void __init root_nfs_print(void) 341 { 342 printk(KERN_NOTICE "Root-NFS: Mounting %s on server %s as root\n", 343 nfs_path, nfs_data.hostname); 344 printk(KERN_NOTICE "Root-NFS: rsize = %d, wsize = %d, timeo = %d, retrans = %d\n", 345 nfs_data.rsize, nfs_data.wsize, nfs_data.timeo, nfs_data.retrans); 346 printk(KERN_NOTICE "Root-NFS: acreg (min,max) = (%d,%d), acdir (min,max) = (%d,%d)\n", 347 nfs_data.acregmin, nfs_data.acregmax, 348 nfs_data.acdirmin, nfs_data.acdirmax); 349 printk(KERN_NOTICE "Root-NFS: nfsd port = %d, mountd port = %d, flags = %08x\n", 350 nfs_port, mount_port, nfs_data.flags); 351 } 352 #endif 353 354 355 static int __init root_nfs_init(void) 356 { 357 #ifdef NFSROOT_DEBUG 358 nfs_debug |= NFSDBG_ROOT; 359 #endif 360 361 /* 362 * Decode the root directory path name and NFS options from 363 * the kernel command line. This has to go here in order to 364 * be able to use the client IP address for the remote root 365 * directory (necessary for pure RARP booting). 366 */ 367 if (root_nfs_name(nfs_root_name) < 0 || 368 root_nfs_addr() < 0) 369 return -1; 370 371 #ifdef NFSROOT_DEBUG 372 root_nfs_print(); 373 #endif 374 375 return 0; 376 } 377 378 379 /* 380 * Parse NFS server and directory information passed on the kernel 381 * command line. 382 */ 383 static int __init nfs_root_setup(char *line) 384 { 385 ROOT_DEV = Root_NFS; 386 if (line[0] == '/' || line[0] == ',' || (line[0] >= '0' && line[0] <= '9')) { 387 strlcpy(nfs_root_name, line, sizeof(nfs_root_name)); 388 } else { 389 int n = strlen(line) + sizeof(NFS_ROOT) - 1; 390 if (n >= sizeof(nfs_root_name)) 391 line[sizeof(nfs_root_name) - sizeof(NFS_ROOT) - 2] = '\0'; 392 sprintf(nfs_root_name, NFS_ROOT, line); 393 } 394 root_server_addr = root_nfs_parse_addr(nfs_root_name); 395 return 1; 396 } 397 398 __setup("nfsroot=", nfs_root_setup); 399 400 /*************************************************************************** 401 402 Routines to actually mount the root directory 403 404 ***************************************************************************/ 405 406 /* 407 * Construct sockaddr_in from address and port number. 408 */ 409 static inline void 410 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port) 411 { 412 sin->sin_family = AF_INET; 413 sin->sin_addr.s_addr = addr; 414 sin->sin_port = port; 415 } 416 417 /* 418 * Query server portmapper for the port of a daemon program. 419 */ 420 static int __init root_nfs_getport(int program, int version, int proto) 421 { 422 struct sockaddr_in sin; 423 424 printk(KERN_NOTICE "Looking up port of RPC %d/%d on %u.%u.%u.%u\n", 425 program, version, NIPQUAD(servaddr)); 426 set_sockaddr(&sin, servaddr, 0); 427 return rpcb_getport_sync(&sin, program, version, proto); 428 } 429 430 431 /* 432 * Use portmapper to find mountd and nfsd port numbers if not overriden 433 * by the user. Use defaults if portmapper is not available. 434 * XXX: Is there any nfs server with no portmapper? 435 */ 436 static 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 */ 484 static int __init root_nfs_get_handle(void) 485 { 486 struct nfs_fh fh; 487 struct sockaddr_in sin; 488 int status; 489 int protocol = (nfs_data.flags & NFS_MOUNT_TCP) ? 490 XPRT_TRANSPORT_TCP : XPRT_TRANSPORT_UDP; 491 int version = (nfs_data.flags & NFS_MOUNT_VER3) ? 492 NFS_MNT3_VERSION : NFS_MNT_VERSION; 493 494 set_sockaddr(&sin, servaddr, htons(mount_port)); 495 status = nfs_mount((struct sockaddr *) &sin, sizeof(sin), NULL, 496 nfs_path, version, protocol, &fh); 497 if (status < 0) 498 printk(KERN_ERR "Root-NFS: Server returned error %d " 499 "while mounting %s\n", status, nfs_path); 500 else { 501 nfs_data.root.size = fh.size; 502 memcpy(nfs_data.root.data, fh.data, fh.size); 503 } 504 505 return status; 506 } 507 508 /* 509 * Get the NFS port numbers and file handle, and return the prepared 'data' 510 * argument for mount() if everything went OK. Return NULL otherwise. 511 */ 512 void * __init nfs_root_data(void) 513 { 514 if (root_nfs_init() < 0 515 || root_nfs_ports() < 0 516 || root_nfs_get_handle() < 0) 517 return NULL; 518 set_sockaddr((struct sockaddr_in *) &nfs_data.addr, servaddr, htons(nfs_port)); 519 return (void*)&nfs_data; 520 } 521