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 #include "internal.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 __be32 servaddr __initdata = 0; 103 104 /* Name of directory to mount */ 105 static char nfs_export_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 __initconst 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 case Opt_nointr: 232 break; 233 case Opt_posix: 234 nfs_data.flags |= NFS_MOUNT_POSIX; 235 break; 236 case Opt_noposix: 237 nfs_data.flags &= ~NFS_MOUNT_POSIX; 238 break; 239 case Opt_cto: 240 nfs_data.flags &= ~NFS_MOUNT_NOCTO; 241 break; 242 case Opt_nocto: 243 nfs_data.flags |= NFS_MOUNT_NOCTO; 244 break; 245 case Opt_ac: 246 nfs_data.flags &= ~NFS_MOUNT_NOAC; 247 break; 248 case Opt_noac: 249 nfs_data.flags |= NFS_MOUNT_NOAC; 250 break; 251 case Opt_lock: 252 nfs_data.flags &= ~NFS_MOUNT_NONLM; 253 break; 254 case Opt_nolock: 255 nfs_data.flags |= NFS_MOUNT_NONLM; 256 break; 257 case Opt_v2: 258 nfs_data.flags &= ~NFS_MOUNT_VER3; 259 break; 260 case Opt_v3: 261 nfs_data.flags |= NFS_MOUNT_VER3; 262 break; 263 case Opt_udp: 264 nfs_data.flags &= ~NFS_MOUNT_TCP; 265 break; 266 case Opt_tcp: 267 nfs_data.flags |= NFS_MOUNT_TCP; 268 break; 269 case Opt_acl: 270 nfs_data.flags &= ~NFS_MOUNT_NOACL; 271 break; 272 case Opt_noacl: 273 nfs_data.flags |= NFS_MOUNT_NOACL; 274 break; 275 default: 276 printk(KERN_WARNING "Root-NFS: unknown " 277 "option: %s\n", p); 278 return 0; 279 } 280 } 281 282 return 1; 283 } 284 285 /* 286 * Prepare the NFS data structure and parse all options. 287 */ 288 static int __init root_nfs_name(char *name) 289 { 290 static char buf[NFS_MAXPATHLEN] __initdata; 291 char *cp; 292 293 /* Set some default values */ 294 memset(&nfs_data, 0, sizeof(nfs_data)); 295 nfs_port = -1; 296 nfs_data.version = NFS_MOUNT_VERSION; 297 nfs_data.flags = NFS_MOUNT_NONLM; /* No lockd in nfs root yet */ 298 nfs_data.rsize = NFS_DEF_FILE_IO_SIZE; 299 nfs_data.wsize = NFS_DEF_FILE_IO_SIZE; 300 nfs_data.acregmin = NFS_DEF_ACREGMIN; 301 nfs_data.acregmax = NFS_DEF_ACREGMAX; 302 nfs_data.acdirmin = NFS_DEF_ACDIRMIN; 303 nfs_data.acdirmax = NFS_DEF_ACDIRMAX; 304 strcpy(buf, NFS_ROOT); 305 306 /* Process options received from the remote server */ 307 root_nfs_parse(root_server_path, buf); 308 309 /* Override them by options set on kernel command-line */ 310 root_nfs_parse(name, buf); 311 312 cp = utsname()->nodename; 313 if (strlen(buf) + strlen(cp) > NFS_MAXPATHLEN) { 314 printk(KERN_ERR "Root-NFS: Pathname for remote directory too long.\n"); 315 return -1; 316 } 317 sprintf(nfs_export_path, buf, cp); 318 319 return 1; 320 } 321 322 323 /* 324 * Get NFS server address. 325 */ 326 static int __init root_nfs_addr(void) 327 { 328 if ((servaddr = root_server_addr) == htonl(INADDR_NONE)) { 329 printk(KERN_ERR "Root-NFS: No NFS server available, giving up.\n"); 330 return -1; 331 } 332 333 snprintf(nfs_data.hostname, sizeof(nfs_data.hostname), 334 "%pI4", &servaddr); 335 return 0; 336 } 337 338 /* 339 * Tell the user what's going on. 340 */ 341 #ifdef NFSROOT_DEBUG 342 static void __init root_nfs_print(void) 343 { 344 printk(KERN_NOTICE "Root-NFS: Mounting %s on server %s as root\n", 345 nfs_export_path, nfs_data.hostname); 346 printk(KERN_NOTICE "Root-NFS: rsize = %d, wsize = %d, timeo = %d, retrans = %d\n", 347 nfs_data.rsize, nfs_data.wsize, nfs_data.timeo, nfs_data.retrans); 348 printk(KERN_NOTICE "Root-NFS: acreg (min,max) = (%d,%d), acdir (min,max) = (%d,%d)\n", 349 nfs_data.acregmin, nfs_data.acregmax, 350 nfs_data.acdirmin, nfs_data.acdirmax); 351 printk(KERN_NOTICE "Root-NFS: nfsd port = %d, mountd port = %d, flags = %08x\n", 352 nfs_port, mount_port, nfs_data.flags); 353 } 354 #endif 355 356 357 static int __init root_nfs_init(void) 358 { 359 #ifdef NFSROOT_DEBUG 360 nfs_debug |= NFSDBG_ROOT; 361 #endif 362 363 /* 364 * Decode the root directory path name and NFS options from 365 * the kernel command line. This has to go here in order to 366 * be able to use the client IP address for the remote root 367 * directory (necessary for pure RARP booting). 368 */ 369 if (root_nfs_name(nfs_root_name) < 0 || 370 root_nfs_addr() < 0) 371 return -1; 372 373 #ifdef NFSROOT_DEBUG 374 root_nfs_print(); 375 #endif 376 377 return 0; 378 } 379 380 381 /* 382 * Parse NFS server and directory information passed on the kernel 383 * command line. 384 */ 385 static int __init nfs_root_setup(char *line) 386 { 387 ROOT_DEV = Root_NFS; 388 if (line[0] == '/' || line[0] == ',' || (line[0] >= '0' && line[0] <= '9')) { 389 strlcpy(nfs_root_name, line, sizeof(nfs_root_name)); 390 } else { 391 int n = strlen(line) + sizeof(NFS_ROOT) - 1; 392 if (n >= sizeof(nfs_root_name)) 393 line[sizeof(nfs_root_name) - sizeof(NFS_ROOT) - 2] = '\0'; 394 sprintf(nfs_root_name, NFS_ROOT, line); 395 } 396 root_server_addr = root_nfs_parse_addr(nfs_root_name); 397 return 1; 398 } 399 400 __setup("nfsroot=", nfs_root_setup); 401 402 /*************************************************************************** 403 404 Routines to actually mount the root directory 405 406 ***************************************************************************/ 407 408 /* 409 * Construct sockaddr_in from address and port number. 410 */ 411 static inline void 412 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port) 413 { 414 sin->sin_family = AF_INET; 415 sin->sin_addr.s_addr = addr; 416 sin->sin_port = port; 417 } 418 419 /* 420 * Query server portmapper for the port of a daemon program. 421 */ 422 static int __init root_nfs_getport(int program, int version, int proto) 423 { 424 struct sockaddr_in sin; 425 426 printk(KERN_NOTICE "Looking up port of RPC %d/%d on %pI4\n", 427 program, version, &servaddr); 428 set_sockaddr(&sin, servaddr, 0); 429 return rpcb_getport_sync(&sin, program, version, proto); 430 } 431 432 433 /* 434 * Use portmapper to find mountd and nfsd port numbers if not overriden 435 * by the user. Use defaults if portmapper is not available. 436 * XXX: Is there any nfs server with no portmapper? 437 */ 438 static int __init root_nfs_ports(void) 439 { 440 int port; 441 int nfsd_ver, mountd_ver; 442 int nfsd_port, mountd_port; 443 int proto; 444 445 if (nfs_data.flags & NFS_MOUNT_VER3) { 446 nfsd_ver = NFS3_VERSION; 447 mountd_ver = NFS_MNT3_VERSION; 448 nfsd_port = NFS_PORT; 449 mountd_port = NFS_MNT_PORT; 450 } else { 451 nfsd_ver = NFS2_VERSION; 452 mountd_ver = NFS_MNT_VERSION; 453 nfsd_port = NFS_PORT; 454 mountd_port = NFS_MNT_PORT; 455 } 456 457 proto = (nfs_data.flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP; 458 459 if (nfs_port < 0) { 460 if ((port = root_nfs_getport(NFS_PROGRAM, nfsd_ver, proto)) < 0) { 461 printk(KERN_ERR "Root-NFS: Unable to get nfsd port " 462 "number from server, using default\n"); 463 port = nfsd_port; 464 } 465 nfs_port = port; 466 dprintk("Root-NFS: Portmapper on server returned %d " 467 "as nfsd port\n", port); 468 } 469 470 if ((port = root_nfs_getport(NFS_MNT_PROGRAM, mountd_ver, proto)) < 0) { 471 printk(KERN_ERR "Root-NFS: Unable to get mountd port " 472 "number from server, using default\n"); 473 port = mountd_port; 474 } 475 mount_port = port; 476 dprintk("Root-NFS: mountd port is %d\n", port); 477 478 return 0; 479 } 480 481 482 /* 483 * Get a file handle from the server for the directory which is to be 484 * mounted. 485 */ 486 static int __init root_nfs_get_handle(void) 487 { 488 struct nfs_fh fh; 489 struct sockaddr_in sin; 490 struct nfs_mount_request request = { 491 .sap = (struct sockaddr *)&sin, 492 .salen = sizeof(sin), 493 .dirpath = nfs_export_path, 494 .version = (nfs_data.flags & NFS_MOUNT_VER3) ? 495 NFS_MNT3_VERSION : NFS_MNT_VERSION, 496 .protocol = (nfs_data.flags & NFS_MOUNT_TCP) ? 497 XPRT_TRANSPORT_TCP : XPRT_TRANSPORT_UDP, 498 .fh = &fh, 499 }; 500 int status; 501 502 set_sockaddr(&sin, servaddr, htons(mount_port)); 503 status = nfs_mount(&request); 504 if (status < 0) 505 printk(KERN_ERR "Root-NFS: Server returned error %d " 506 "while mounting %s\n", status, nfs_export_path); 507 else { 508 nfs_data.root.size = fh.size; 509 memcpy(nfs_data.root.data, fh.data, fh.size); 510 } 511 512 return status; 513 } 514 515 /* 516 * Get the NFS port numbers and file handle, and return the prepared 'data' 517 * argument for mount() if everything went OK. Return NULL otherwise. 518 */ 519 void * __init nfs_root_data(void) 520 { 521 if (root_nfs_init() < 0 522 || root_nfs_ports() < 0 523 || root_nfs_get_handle() < 0) 524 return NULL; 525 set_sockaddr((struct sockaddr_in *) &nfs_data.addr, servaddr, htons(nfs_port)); 526 return (void*)&nfs_data; 527 } 528