/* * $Id: nfsroot.c,v 1.1.1.1 2003/06/23 22:18:38 jharrell Exp $ * * Copyright (C) 1995, 1996 Gero Kuhlmann * * Allow an NFS filesystem to be mounted as root. The way this works is: * (1) Use the IP autoconfig mechanism to set local IP addresses and routes. * (2) Handle RPC negotiation with the system which replied to RARP or * was reported as a boot server by BOOTP or manually. * (3) The actual mounting is done later, when init() is running. * * * Changes: * * Alan Cox : Removed get_address name clash with FPU. * Alan Cox : Reformatted a bit. * Gero Kuhlmann : Code cleanup * Michael Rausch : Fixed recognition of an incoming RARP answer. * Martin Mares : (2.0) Auto-configuration via BOOTP supported. * Martin Mares : Manual selection of interface & BOOTP/RARP. * Martin Mares : Using network routes instead of host routes, * allowing the default configuration to be used * for normal operation of the host. * Martin Mares : Randomized timer with exponential backoff * installed to minimize network congestion. * Martin Mares : Code cleanup. * Martin Mares : (2.1) BOOTP and RARP made configuration options. * Martin Mares : Server hostname generation fixed. * Gerd Knorr : Fixed wired inode handling * Martin Mares : (2.2) "0.0.0.0" addresses from command line ignored. * Martin Mares : RARP replies not tested for server address. * Gero Kuhlmann : (2.3) Some bug fixes and code cleanup again (please * send me your new patches _before_ bothering * Linus so that I don' always have to cleanup * _afterwards_ - thanks) * Gero Kuhlmann : Last changes of Martin Mares undone. * Gero Kuhlmann : RARP replies are tested for specified server * again. However, it's now possible to have * different RARP and NFS servers. * Gero Kuhlmann : "0.0.0.0" addresses from command line are * now mapped to INADDR_NONE. * Gero Kuhlmann : Fixed a bug which prevented BOOTP path name * from being used (thanks to Leo Spiekman) * Andy Walker : Allow to specify the NFS server in nfs_root * without giving a path name * Swen Th’mmler : Allow to specify the NFS options in nfs_root * without giving a path name. Fix BOOTP request * for domainname (domainname is NIS domain, not * DNS domain!). Skip dummy devices for BOOTP. * Jacek Zapala : Fixed a bug which prevented server-ip address * from nfsroot parameter from being used. * Olaf Kirch : Adapted to new NFS code. * Jakub Jelinek : Free used code segment. * Marko Kohtala : Fixed some bugs. * Martin Mares : Debug message cleanup * Martin Mares : Changed to use the new generic IP layer autoconfig * code. BOOTP and RARP moved there. * Martin Mares : Default path now contains host name instead of * host IP address (but host name defaults to IP * address anyway). * Martin Mares : Use root_server_addr appropriately during setup. * Martin Mares : Rewrote parameter parsing, now hopefully giving * correct overriding. * Trond Myklebust : Add in preliminary support for NFSv3 and TCP. * Fix bug in root_nfs_addr(). nfs_data.namlen * is NOT for the length of the hostname. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Define this to allow debugging output */ #undef NFSROOT_DEBUG #define NFSDBG_FACILITY NFSDBG_ROOT /* Default path we try to mount. "%s" gets replaced by our IP address */ #define NFS_ROOT "/tftpboot/%s" /* Parameters passed from the kernel command line */ static char nfs_root_name[256] __initdata = ""; /* Address of NFS server */ static __u32 servaddr __initdata = 0; /* Name of directory to mount */ static char nfs_path[NFS_MAXPATHLEN] __initdata = { 0, }; /* NFS-related data */ static struct nfs_mount_data nfs_data __initdata = { 0, };/* NFS mount info */ static int nfs_port __initdata = 0; /* Port to connect to for NFS */ static int mount_port __initdata = 0; /* Mount daemon port number */ /*************************************************************************** Parsing of options ***************************************************************************/ /* * The following integer options are recognized */ static struct nfs_int_opts { char *name; int *val; } root_int_opts[] __initdata = { { "port", &nfs_port }, { "rsize", &nfs_data.rsize }, { "wsize", &nfs_data.wsize }, { "timeo", &nfs_data.timeo }, { "retrans", &nfs_data.retrans }, { "acregmin", &nfs_data.acregmin }, { "acregmax", &nfs_data.acregmax }, { "acdirmin", &nfs_data.acdirmin }, { "acdirmax", &nfs_data.acdirmax }, { NULL, NULL } }; /* * And now the flag options */ static struct nfs_bool_opts { char *name; int and_mask; int or_mask; } root_bool_opts[] __initdata = { { "soft", ~NFS_MOUNT_SOFT, NFS_MOUNT_SOFT }, { "hard", ~NFS_MOUNT_SOFT, 0 }, { "intr", ~NFS_MOUNT_INTR, NFS_MOUNT_INTR }, { "nointr", ~NFS_MOUNT_INTR, 0 }, { "posix", ~NFS_MOUNT_POSIX, NFS_MOUNT_POSIX }, { "noposix", ~NFS_MOUNT_POSIX, 0 }, { "cto", ~NFS_MOUNT_NOCTO, 0 }, { "nocto", ~NFS_MOUNT_NOCTO, NFS_MOUNT_NOCTO }, { "ac", ~NFS_MOUNT_NOAC, 0 }, { "noac", ~NFS_MOUNT_NOAC, NFS_MOUNT_NOAC }, { "lock", ~NFS_MOUNT_NONLM, 0 }, { "nolock", ~NFS_MOUNT_NONLM, NFS_MOUNT_NONLM }, #ifdef CONFIG_NFS_V3 { "v2", ~NFS_MOUNT_VER3, 0 }, { "v3", ~NFS_MOUNT_VER3, NFS_MOUNT_VER3 }, #endif { "udp", ~NFS_MOUNT_TCP, 0 }, { "tcp", ~NFS_MOUNT_TCP, NFS_MOUNT_TCP }, { "broken_suid",~NFS_MOUNT_BROKEN_SUID, NFS_MOUNT_BROKEN_SUID }, { NULL, 0, 0 } }; /* * Extract IP address from the parameter string if needed. Note that we * need to have root_server_addr set _before_ IPConfig gets called as it * can override it. */ static void __init root_nfs_parse_addr(char *name) { int octets = 0; char *cp, *cq; cp = cq = name; while (octets < 4) { while (*cp >= '0' && *cp <= '9') cp++; if (cp == cq || cp - cq > 3) break; if (*cp == '.' || octets == 3) octets++; if (octets < 4) cp++; cq = cp; } if (octets == 4 && (*cp == ':' || *cp == '\0')) { if (*cp == ':') *cp++ = '\0'; root_server_addr = in_aton(name); strcpy(name, cp); } } /* * Parse option string. */ static void __init root_nfs_parse(char *name, char *buf) { char *options, *val, *cp; if ((options = strchr(name, ','))) { *options++ = 0; cp = strtok(options, ","); while (cp) { if ((val = strchr(cp, '='))) { struct nfs_int_opts *opts = root_int_opts; *val++ = '\0'; while (opts->name && strcmp(opts->name, cp)) opts++; if (opts->name) *(opts->val) = (int) simple_strtoul(val, NULL, 10); } else { struct nfs_bool_opts *opts = root_bool_opts; while (opts->name && strcmp(opts->name, cp)) opts++; if (opts->name) { nfs_data.flags &= opts->and_mask; nfs_data.flags |= opts->or_mask; } } cp = strtok(NULL, ","); } } if (name[0] && strcmp(name, "default")) { strncpy(buf, name, NFS_MAXPATHLEN-1); buf[NFS_MAXPATHLEN-1] = 0; } } /* * Prepare the NFS data structure and parse all options. */ static int __init root_nfs_name(char *name) { char buf[NFS_MAXPATHLEN]; char *cp; /* Set some default values */ memset(&nfs_data, 0, sizeof(nfs_data)); nfs_port = -1; nfs_data.version = NFS_MOUNT_VERSION; nfs_data.flags = NFS_MOUNT_NONLM; /* No lockd in nfs root yet */ nfs_data.rsize = NFS_DEF_FILE_IO_BUFFER_SIZE; nfs_data.wsize = NFS_DEF_FILE_IO_BUFFER_SIZE; nfs_data.bsize = 0; nfs_data.timeo = 7; nfs_data.retrans = 3; nfs_data.acregmin = 3; nfs_data.acregmax = 60; nfs_data.acdirmin = 30; nfs_data.acdirmax = 60; strcpy(buf, NFS_ROOT); /* Process options received from the remote server */ root_nfs_parse(root_server_path, buf); /* Override them by options set on kernel command-line */ root_nfs_parse(name, buf); cp = system_utsname.nodename; if (strlen(buf) + strlen(cp) > NFS_MAXPATHLEN) { printk(KERN_ERR "Root-NFS: Pathname for remote directory too long.\n"); return -1; } sprintf(nfs_path, buf, cp); return 1; } /* * Get NFS server address. */ static int __init root_nfs_addr(void) { if ((servaddr = root_server_addr) == INADDR_NONE) { printk(KERN_ERR "Root-NFS: No NFS server available, giving up.\n"); return -1; } strncpy(nfs_data.hostname, in_ntoa(servaddr), sizeof(nfs_data.hostname)-1); return 0; } /* * Tell the user what's going on. */ #ifdef NFSROOT_DEBUG static void __init root_nfs_print(void) { printk(KERN_NOTICE "Root-NFS: Mounting %s on server %s as root\n", nfs_path, nfs_data.hostname); printk(KERN_NOTICE "Root-NFS: rsize = %d, wsize = %d, timeo = %d, retrans = %d\n", nfs_data.rsize, nfs_data.wsize, nfs_data.timeo, nfs_data.retrans); printk(KERN_NOTICE "Root-NFS: acreg (min,max) = (%d,%d), acdir (min,max) = (%d,%d)\n", nfs_data.acregmin, nfs_data.acregmax, nfs_data.acdirmin, nfs_data.acdirmax); printk(KERN_NOTICE "Root-NFS: nfsd port = %d, mountd port = %d, flags = %08x\n", nfs_port, mount_port, nfs_data.flags); } #endif int __init root_nfs_init(void) { #ifdef NFSROOT_DEBUG nfs_debug |= NFSDBG_ROOT; #endif /* * Decode the root directory path name and NFS options from * the kernel command line. This has to go here in order to * be able to use the client IP address for the remote root * directory (necessary for pure RARP booting). */ if (root_nfs_name(nfs_root_name) < 0 || root_nfs_addr() < 0) return -1; #ifdef NFSROOT_DEBUG root_nfs_print(); #endif return 0; } /* * Parse NFS server and directory information passed on the kernel * command line. */ int __init nfs_root_setup(char *line) { ROOT_DEV = MKDEV(UNNAMED_MAJOR, 255); if (line[0] == '/' || line[0] == ',' || (line[0] >= '0' && line[0] <= '9')) { strncpy(nfs_root_name, line, sizeof(nfs_root_name)); nfs_root_name[sizeof(nfs_root_name)-1] = '\0'; } else { int n = strlen(line) + strlen(NFS_ROOT); if (n >= sizeof(nfs_root_name)) line[sizeof(nfs_root_name) - strlen(NFS_ROOT) - 1] = '\0'; sprintf(nfs_root_name, NFS_ROOT, line); } root_nfs_parse_addr(nfs_root_name); return 1; } __setup("nfsroot=", nfs_root_setup); /*************************************************************************** Routines to actually mount the root directory ***************************************************************************/ /* * Construct sockaddr_in from address and port number. */ static inline void set_sockaddr(struct sockaddr_in *sin, __u32 addr, __u16 port) { sin->sin_family = AF_INET; sin->sin_addr.s_addr = addr; sin->sin_port = port; } /* * Query server portmapper for the port of a daemon program. */ static int __init root_nfs_getport(int program, int version, int proto) { struct sockaddr_in sin; printk(KERN_NOTICE "Looking up port of RPC %d/%d on %s\n", program, version, in_ntoa(servaddr)); set_sockaddr(&sin, servaddr, 0); return rpc_getport_external(&sin, program, version, proto); } /* * Use portmapper to find mountd and nfsd port numbers if not overriden * by the user. Use defaults if portmapper is not available. * XXX: Is there any nfs server with no portmapper? */ static int __init root_nfs_ports(void) { int port; int nfsd_ver, mountd_ver; int nfsd_port, mountd_port; int proto; if (nfs_data.flags & NFS_MOUNT_VER3) { nfsd_ver = NFS3_VERSION; mountd_ver = NFS_MNT3_VERSION; nfsd_port = NFS_PORT; mountd_port = NFS_MNT_PORT; } else { nfsd_ver = NFS2_VERSION; mountd_ver = NFS_MNT_VERSION; nfsd_port = NFS_PORT; mountd_port = NFS_MNT_PORT; } proto = (nfs_data.flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP; if (nfs_port < 0) { if ((port = root_nfs_getport(NFS_PROGRAM, nfsd_ver, proto)) < 0) { printk(KERN_ERR "Root-NFS: Unable to get nfsd port " "number from server, using default\n"); port = nfsd_port; } nfs_port = htons(port); dprintk("Root-NFS: Portmapper on server returned %d " "as nfsd port\n", port); } if ((port = root_nfs_getport(NFS_MNT_PROGRAM, mountd_ver, proto)) < 0) { printk(KERN_ERR "Root-NFS: Unable to get mountd port " "number from server, using default\n"); port = mountd_port; } mount_port = htons(port); dprintk("Root-NFS: mountd port is %d\n", port); return 0; } /* * Get a file handle from the server for the directory which is to be * mounted. */ static int __init root_nfs_get_handle(void) { struct sockaddr_in sin; int status; set_sockaddr(&sin, servaddr, mount_port); if (nfs_data.flags & NFS_MOUNT_VER3) status = nfs3_mount(&sin, nfs_path, &nfs_data.root); else status = nfs_mount(&sin, nfs_path, &nfs_data.root); if (status < 0) printk(KERN_ERR "Root-NFS: Server returned error %d " "while mounting %s\n", status, nfs_path); return status; } /* * Get the NFS port numbers and file handle, and return the prepared 'data' * argument for ->read_super() if everything went OK. Return NULL otherwise. */ void * __init nfs_root_data(void) { if (root_nfs_init() < 0 || root_nfs_ports() < 0 || root_nfs_get_handle() < 0) return NULL; set_sockaddr((struct sockaddr_in *) &nfs_data.addr, servaddr, nfs_port); return (void*)&nfs_data; }