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/config.h> 73 #include <linux/types.h> 74 #include <linux/string.h> 75 #include <linux/kernel.h> 76 #include <linux/time.h> 77 #include <linux/fs.h> 78 #include <linux/init.h> 79 #include <linux/sunrpc/clnt.h> 80 #include <linux/nfs.h> 81 #include <linux/nfs_fs.h> 82 #include <linux/nfs_mount.h> 83 #include <linux/in.h> 84 #include <linux/major.h> 85 #include <linux/utsname.h> 86 #include <linux/inet.h> 87 #include <linux/root_dev.h> 88 #include <net/ipconfig.h> 89 #include <linux/parser.h> 90 91 /* Define this to allow debugging output */ 92 #undef NFSROOT_DEBUG 93 #define NFSDBG_FACILITY NFSDBG_ROOT 94 95 /* Default path we try to mount. "%s" gets replaced by our IP address */ 96 #define NFS_ROOT "/tftpboot/%s" 97 98 /* Parameters passed from the kernel command line */ 99 static char nfs_root_name[256] __initdata = ""; 100 101 /* Address of NFS server */ 102 static __u32 servaddr __initdata = 0; 103 104 /* Name of directory to mount */ 105 static char nfs_path[NFS_MAXPATHLEN] __initdata = { 0, }; 106 107 /* NFS-related data */ 108 static struct nfs_mount_data nfs_data __initdata = { 0, };/* NFS mount info */ 109 static int nfs_port __initdata = 0; /* Port to connect to for NFS */ 110 static int mount_port __initdata = 0; /* Mount daemon port number */ 111 112 113 /*************************************************************************** 114 115 Parsing of options 116 117 ***************************************************************************/ 118 119 enum { 120 /* Options that take integer arguments */ 121 Opt_port, Opt_rsize, Opt_wsize, Opt_timeo, Opt_retrans, Opt_acregmin, 122 Opt_acregmax, Opt_acdirmin, Opt_acdirmax, 123 /* Options that take no arguments */ 124 Opt_soft, Opt_hard, Opt_intr, 125 Opt_nointr, Opt_posix, Opt_noposix, Opt_cto, Opt_nocto, Opt_ac, 126 Opt_noac, Opt_lock, Opt_nolock, Opt_v2, Opt_v3, Opt_udp, Opt_tcp, 127 Opt_acl, Opt_noacl, 128 /* Error token */ 129 Opt_err 130 }; 131 132 static match_table_t __initdata tokens = { 133 {Opt_port, "port=%u"}, 134 {Opt_rsize, "rsize=%u"}, 135 {Opt_wsize, "wsize=%u"}, 136 {Opt_timeo, "timeo=%u"}, 137 {Opt_retrans, "retrans=%u"}, 138 {Opt_acregmin, "acregmin=%u"}, 139 {Opt_acregmax, "acregmax=%u"}, 140 {Opt_acdirmin, "acdirmin=%u"}, 141 {Opt_acdirmax, "acdirmax=%u"}, 142 {Opt_soft, "soft"}, 143 {Opt_hard, "hard"}, 144 {Opt_intr, "intr"}, 145 {Opt_nointr, "nointr"}, 146 {Opt_posix, "posix"}, 147 {Opt_noposix, "noposix"}, 148 {Opt_cto, "cto"}, 149 {Opt_nocto, "nocto"}, 150 {Opt_ac, "ac"}, 151 {Opt_noac, "noac"}, 152 {Opt_lock, "lock"}, 153 {Opt_nolock, "nolock"}, 154 {Opt_v2, "nfsvers=2"}, 155 {Opt_v2, "v2"}, 156 {Opt_v3, "nfsvers=3"}, 157 {Opt_v3, "v3"}, 158 {Opt_udp, "proto=udp"}, 159 {Opt_udp, "udp"}, 160 {Opt_tcp, "proto=tcp"}, 161 {Opt_tcp, "tcp"}, 162 {Opt_acl, "acl"}, 163 {Opt_noacl, "noacl"}, 164 {Opt_err, NULL} 165 166 }; 167 168 /* 169 * Parse option string. 170 */ 171 172 static int __init root_nfs_parse(char *name, char *buf) 173 { 174 175 char *p; 176 substring_t args[MAX_OPT_ARGS]; 177 int option; 178 179 if (!name) 180 return 1; 181 182 /* Set the NFS remote path */ 183 p = strsep(&name, ","); 184 if (p[0] != '\0' && strcmp(p, "default") != 0) 185 strlcpy(buf, p, NFS_MAXPATHLEN); 186 187 while ((p = strsep (&name, ",")) != NULL) { 188 int token; 189 if (!*p) 190 continue; 191 token = match_token(p, tokens, args); 192 193 /* %u tokens only. Beware if you add new tokens! */ 194 if (token < Opt_soft && match_int(&args[0], &option)) 195 return 0; 196 switch (token) { 197 case Opt_port: 198 nfs_port = option; 199 break; 200 case Opt_rsize: 201 nfs_data.rsize = option; 202 break; 203 case Opt_wsize: 204 nfs_data.wsize = option; 205 break; 206 case Opt_timeo: 207 nfs_data.timeo = option; 208 break; 209 case Opt_retrans: 210 nfs_data.retrans = option; 211 break; 212 case Opt_acregmin: 213 nfs_data.acregmin = option; 214 break; 215 case Opt_acregmax: 216 nfs_data.acregmax = option; 217 break; 218 case Opt_acdirmin: 219 nfs_data.acdirmin = option; 220 break; 221 case Opt_acdirmax: 222 nfs_data.acdirmax = option; 223 break; 224 case Opt_soft: 225 nfs_data.flags |= NFS_MOUNT_SOFT; 226 break; 227 case Opt_hard: 228 nfs_data.flags &= ~NFS_MOUNT_SOFT; 229 break; 230 case Opt_intr: 231 nfs_data.flags |= NFS_MOUNT_INTR; 232 break; 233 case Opt_nointr: 234 nfs_data.flags &= ~NFS_MOUNT_INTR; 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 */ 291 static 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 = 3; 304 nfs_data.acregmax = 60; 305 nfs_data.acdirmin = 30; 306 nfs_data.acdirmax = 60; 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 = system_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_path, buf, cp); 321 322 return 1; 323 } 324 325 326 /* 327 * Get NFS server address. 328 */ 329 static int __init root_nfs_addr(void) 330 { 331 if ((servaddr = root_server_addr) == 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 "%u.%u.%u.%u", NIPQUAD(servaddr)); 338 return 0; 339 } 340 341 /* 342 * Tell the user what's going on. 343 */ 344 #ifdef NFSROOT_DEBUG 345 static void __init root_nfs_print(void) 346 { 347 printk(KERN_NOTICE "Root-NFS: Mounting %s on server %s as root\n", 348 nfs_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 358 359 360 static 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 */ 388 static 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 */ 414 static inline void 415 set_sockaddr(struct sockaddr_in *sin, __u32 addr, __u16 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 */ 425 static 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 %u.%u.%u.%u\n", 430 program, version, NIPQUAD(servaddr)); 431 set_sockaddr(&sin, servaddr, 0); 432 return rpc_getport_external(&sin, program, version, proto); 433 } 434 435 436 /* 437 * Use portmapper to find mountd and nfsd port numbers if not overriden 438 * by the user. Use defaults if portmapper is not available. 439 * XXX: Is there any nfs server with no portmapper? 440 */ 441 static int __init root_nfs_ports(void) 442 { 443 int port; 444 int nfsd_ver, mountd_ver; 445 int nfsd_port, mountd_port; 446 int proto; 447 448 if (nfs_data.flags & NFS_MOUNT_VER3) { 449 nfsd_ver = NFS3_VERSION; 450 mountd_ver = NFS_MNT3_VERSION; 451 nfsd_port = NFS_PORT; 452 mountd_port = NFS_MNT_PORT; 453 } else { 454 nfsd_ver = NFS2_VERSION; 455 mountd_ver = NFS_MNT_VERSION; 456 nfsd_port = NFS_PORT; 457 mountd_port = NFS_MNT_PORT; 458 } 459 460 proto = (nfs_data.flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP; 461 462 if (nfs_port < 0) { 463 if ((port = root_nfs_getport(NFS_PROGRAM, nfsd_ver, proto)) < 0) { 464 printk(KERN_ERR "Root-NFS: Unable to get nfsd port " 465 "number from server, using default\n"); 466 port = nfsd_port; 467 } 468 nfs_port = htons(port); 469 dprintk("Root-NFS: Portmapper on server returned %d " 470 "as nfsd port\n", port); 471 } 472 473 if ((port = root_nfs_getport(NFS_MNT_PROGRAM, mountd_ver, proto)) < 0) { 474 printk(KERN_ERR "Root-NFS: Unable to get mountd port " 475 "number from server, using default\n"); 476 port = mountd_port; 477 } 478 mount_port = htons(port); 479 dprintk("Root-NFS: mountd port is %d\n", port); 480 481 return 0; 482 } 483 484 485 /* 486 * Get a file handle from the server for the directory which is to be 487 * mounted. 488 */ 489 static int __init root_nfs_get_handle(void) 490 { 491 struct nfs_fh fh; 492 struct sockaddr_in sin; 493 int status; 494 int protocol = (nfs_data.flags & NFS_MOUNT_TCP) ? 495 IPPROTO_TCP : IPPROTO_UDP; 496 int version = (nfs_data.flags & NFS_MOUNT_VER3) ? 497 NFS_MNT3_VERSION : NFS_MNT_VERSION; 498 499 set_sockaddr(&sin, servaddr, mount_port); 500 status = nfsroot_mount(&sin, nfs_path, &fh, version, protocol); 501 if (status < 0) 502 printk(KERN_ERR "Root-NFS: Server returned error %d " 503 "while mounting %s\n", status, nfs_path); 504 else { 505 nfs_data.root.size = fh.size; 506 memcpy(nfs_data.root.data, fh.data, fh.size); 507 } 508 509 return status; 510 } 511 512 /* 513 * Get the NFS port numbers and file handle, and return the prepared 'data' 514 * argument for mount() if everything went OK. Return NULL otherwise. 515 */ 516 void * __init nfs_root_data(void) 517 { 518 if (root_nfs_init() < 0 519 || root_nfs_ports() < 0 520 || root_nfs_get_handle() < 0) 521 return NULL; 522 set_sockaddr((struct sockaddr_in *) &nfs_data.addr, servaddr, nfs_port); 523 return (void*)&nfs_data; 524 } 525