/* * 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) Construct the device string and the options string using DHCP * option 17 and/or kernel command line options. * (3) When mount_root() sets up the root file system, pass these strings * to the NFS client's regular mount interface via sys_mount(). * * * 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 Thümmler : 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. * Hua Qin : Support for mounting root file system via * NFS over TCP. * Fabian Frederick: Option parser rebuilt (using parser lib) * Chuck Lever : Use super.c's text-based mount option parsing */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "internal.h" /* Define this to allow debugging output */ #undef NFSROOT_DEBUG #define NFSDBG_FACILITY NFSDBG_ROOT /* Default port to use if server is not running a portmapper */ #define NFS_MNT_PORT 627 /* 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_parms[256] __initdata = ""; /* Text-based mount options passed to super.c */ static char nfs_root_options[256] __initdata = ""; /* Address of NFS server */ static __be32 servaddr __initdata = 0; /* Name of directory to mount */ static char nfs_export_path[NFS_MAXPATHLEN + 1] __initdata = ""; /* server:export path string passed to super.c */ static char nfs_root_device[NFS_MAXPATHLEN + 1] __initdata = ""; /* 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 ***************************************************************************/ enum { /* Options that take integer arguments */ Opt_port, Opt_rsize, Opt_wsize, Opt_timeo, Opt_retrans, Opt_acregmin, Opt_acregmax, Opt_acdirmin, Opt_acdirmax, /* Options that take no arguments */ Opt_soft, Opt_hard, Opt_intr, Opt_nointr, Opt_posix, Opt_noposix, Opt_cto, Opt_nocto, Opt_ac, Opt_noac, Opt_lock, Opt_nolock, Opt_v2, Opt_v3, Opt_udp, Opt_tcp, Opt_acl, Opt_noacl, /* Error token */ Opt_err }; static const match_table_t tokens __initconst = { {Opt_port, "port=%u"}, {Opt_rsize, "rsize=%u"}, {Opt_wsize, "wsize=%u"}, {Opt_timeo, "timeo=%u"}, {Opt_retrans, "retrans=%u"}, {Opt_acregmin, "acregmin=%u"}, {Opt_acregmax, "acregmax=%u"}, {Opt_acdirmin, "acdirmin=%u"}, {Opt_acdirmax, "acdirmax=%u"}, {Opt_soft, "soft"}, {Opt_hard, "hard"}, {Opt_intr, "intr"}, {Opt_nointr, "nointr"}, {Opt_posix, "posix"}, {Opt_noposix, "noposix"}, {Opt_cto, "cto"}, {Opt_nocto, "nocto"}, {Opt_ac, "ac"}, {Opt_noac, "noac"}, {Opt_lock, "lock"}, {Opt_nolock, "nolock"}, {Opt_v2, "nfsvers=2"}, {Opt_v2, "v2"}, {Opt_v3, "nfsvers=3"}, {Opt_v3, "v3"}, {Opt_udp, "proto=udp"}, {Opt_udp, "udp"}, {Opt_tcp, "proto=tcp"}, {Opt_tcp, "tcp"}, {Opt_acl, "acl"}, {Opt_noacl, "noacl"}, {Opt_err, NULL} }; /* * Parse option string. */ static int __init root_nfs_parse(char *name, char *buf) { char *p; substring_t args[MAX_OPT_ARGS]; int option; if (!name) return 1; /* Set the NFS remote path */ p = strsep(&name, ","); if (p[0] != '\0' && strcmp(p, "default") != 0) strlcpy(buf, p, NFS_MAXPATHLEN); while ((p = strsep (&name, ",")) != NULL) { int token; if (!*p) continue; token = match_token(p, tokens, args); /* %u tokens only. Beware if you add new tokens! */ if (token < Opt_soft && match_int(&args[0], &option)) return 0; switch (token) { case Opt_port: nfs_port = option; break; case Opt_rsize: nfs_data.rsize = option; break; case Opt_wsize: nfs_data.wsize = option; break; case Opt_timeo: nfs_data.timeo = option; break; case Opt_retrans: nfs_data.retrans = option; break; case Opt_acregmin: nfs_data.acregmin = option; break; case Opt_acregmax: nfs_data.acregmax = option; break; case Opt_acdirmin: nfs_data.acdirmin = option; break; case Opt_acdirmax: nfs_data.acdirmax = option; break; case Opt_soft: nfs_data.flags |= NFS_MOUNT_SOFT; break; case Opt_hard: nfs_data.flags &= ~NFS_MOUNT_SOFT; break; case Opt_intr: case Opt_nointr: break; case Opt_posix: nfs_data.flags |= NFS_MOUNT_POSIX; break; case Opt_noposix: nfs_data.flags &= ~NFS_MOUNT_POSIX; break; case Opt_cto: nfs_data.flags &= ~NFS_MOUNT_NOCTO; break; case Opt_nocto: nfs_data.flags |= NFS_MOUNT_NOCTO; break; case Opt_ac: nfs_data.flags &= ~NFS_MOUNT_NOAC; break; case Opt_noac: nfs_data.flags |= NFS_MOUNT_NOAC; break; case Opt_lock: nfs_data.flags &= ~NFS_MOUNT_NONLM; break; case Opt_nolock: nfs_data.flags |= NFS_MOUNT_NONLM; break; case Opt_v2: nfs_data.flags &= ~NFS_MOUNT_VER3; break; case Opt_v3: nfs_data.flags |= NFS_MOUNT_VER3; break; case Opt_udp: nfs_data.flags &= ~NFS_MOUNT_TCP; break; case Opt_tcp: nfs_data.flags |= NFS_MOUNT_TCP; break; case Opt_acl: nfs_data.flags &= ~NFS_MOUNT_NOACL; break; case Opt_noacl: nfs_data.flags |= NFS_MOUNT_NOACL; break; default: printk(KERN_WARNING "Root-NFS: unknown " "option: %s\n", p); return 0; } } return 1; } /* * Prepare the NFS data structure and parse all options. */ static int __init root_nfs_name(char *name) { static char buf[NFS_MAXPATHLEN] __initdata; 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_SIZE; nfs_data.wsize = NFS_DEF_FILE_IO_SIZE; nfs_data.acregmin = NFS_DEF_ACREGMIN; nfs_data.acregmax = NFS_DEF_ACREGMAX; nfs_data.acdirmin = NFS_DEF_ACDIRMIN; nfs_data.acdirmax = NFS_DEF_ACDIRMAX; 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 = 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_export_path, buf, cp); return 1; } /* * Get NFS server address. */ static int __init root_nfs_addr(void) { if ((servaddr = root_server_addr) == htonl(INADDR_NONE)) { printk(KERN_ERR "Root-NFS: No NFS server available, giving up.\n"); return -1; } snprintf(nfs_data.hostname, sizeof(nfs_data.hostname), "%pI4", &servaddr); 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_export_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 static 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_parms) < 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. * * nfsroot=[:][,] * * If there is a "%s" token in the string, it is replaced * by the ASCII-representation of the client's IP address. */ static int __init nfs_root_setup(char *line) { ROOT_DEV = Root_NFS; if (line[0] == '/' || line[0] == ',' || (line[0] >= '0' && line[0] <= '9')) { strlcpy(nfs_root_parms, line, sizeof(nfs_root_parms)); } else { size_t n = strlen(line) + sizeof(NFS_ROOT) - 1; if (n >= sizeof(nfs_root_parms)) line[sizeof(nfs_root_parms) - sizeof(NFS_ROOT) - 2] = '\0'; sprintf(nfs_root_parms, NFS_ROOT, line); } /* * Extract the IP address of the NFS server containing our * root file system, if one was specified. * * Note: root_nfs_parse_addr() removes the server-ip from * nfs_root_parms, if it exists. */ root_server_addr = root_nfs_parse_addr(nfs_root_parms); 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, __be32 addr, __be16 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 %pI4\n", program, version, &servaddr); set_sockaddr(&sin, servaddr, 0); return rpcb_getport_sync(&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 = 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 = 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; unsigned int auth_flav_len = 0; struct nfs_mount_request request = { .sap = (struct sockaddr *)&sin, .salen = sizeof(sin), .dirpath = nfs_export_path, .version = (nfs_data.flags & NFS_MOUNT_VER3) ? NFS_MNT3_VERSION : NFS_MNT_VERSION, .protocol = (nfs_data.flags & NFS_MOUNT_TCP) ? XPRT_TRANSPORT_TCP : XPRT_TRANSPORT_UDP, .auth_flav_len = &auth_flav_len, }; int status = -ENOMEM; request.fh = nfs_alloc_fhandle(); if (!request.fh) goto out; set_sockaddr(&sin, servaddr, htons(mount_port)); status = nfs_mount(&request); if (status < 0) printk(KERN_ERR "Root-NFS: Server returned error %d " "while mounting %s\n", status, nfs_export_path); else { nfs_data.root.size = request.fh->size; memcpy(&nfs_data.root.data, request.fh->data, request.fh->size); } nfs_free_fhandle(request.fh); out: return status; } /* * Get the NFS port numbers and file handle, and return the prepared 'data' * argument for mount() if everything went OK. Return NULL otherwise. */ void * __init old_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, htons(nfs_port)); return (void*)&nfs_data; } static int __init root_nfs_copy(char *dest, const char *src, const size_t destlen) { if (strlcpy(dest, src, destlen) > destlen) return -1; return 0; } static int __init root_nfs_cat(char *dest, const char *src, const size_t destlen) { if (strlcat(dest, src, destlen) > destlen) return -1; return 0; } /* * Parse out root export path and mount options from * passed-in string @incoming. * * Copy the export path into @exppath. */ static int __init root_nfs_parse_options(char *incoming, char *exppath, const size_t exppathlen) { char *p; /* * Set the NFS remote path */ p = strsep(&incoming, ","); if (*p != '\0' && strcmp(p, "default") != 0) if (root_nfs_copy(exppath, p, exppathlen)) return -1; /* * @incoming now points to the rest of the string; if it * contains something, append it to our root options buffer */ if (incoming != NULL && *incoming != '\0') if (root_nfs_cat(nfs_root_options, incoming, sizeof(nfs_root_options))) return -1; /* * Possibly prepare for more options to be appended */ if (nfs_root_options[0] != '\0' && nfs_root_options[strlen(nfs_root_options)] != ',') if (root_nfs_cat(nfs_root_options, ",", sizeof(nfs_root_options))) return -1; return 0; } /* * Decode the export directory path name and NFS options from * the kernel command line. This has to be done late in order to * use a dynamically acquired client IP address for the remote * root directory path. * * Returns zero if successful; otherwise -1 is returned. */ static int __init root_nfs_data(char *cmdline) { char addr_option[sizeof("nolock,addr=") + INET_ADDRSTRLEN + 1]; int len, retval = -1; char *tmp = NULL; const size_t tmplen = sizeof(nfs_export_path); tmp = kzalloc(tmplen, GFP_KERNEL); if (tmp == NULL) goto out_nomem; strcpy(tmp, NFS_ROOT); if (root_server_path[0] != '\0') { dprintk("Root-NFS: DHCPv4 option 17: %s\n", root_server_path); if (root_nfs_parse_options(root_server_path, tmp, tmplen)) goto out_optionstoolong; } if (cmdline[0] != '\0') { dprintk("Root-NFS: nfsroot=%s\n", cmdline); if (root_nfs_parse_options(cmdline, tmp, tmplen)) goto out_optionstoolong; } /* * Append mandatory options for nfsroot so they override * what has come before */ snprintf(addr_option, sizeof(addr_option), "nolock,addr=%pI4", &servaddr); if (root_nfs_cat(nfs_root_options, addr_option, sizeof(nfs_root_options))) goto out_optionstoolong; /* * Set up nfs_root_device. For NFS mounts, this looks like * * server:/path * * At this point, utsname()->nodename contains our local * IP address or hostname, set by ipconfig. If "%s" exists * in tmp, substitute the nodename, then shovel the whole * mess into nfs_root_device. */ len = snprintf(nfs_export_path, sizeof(nfs_export_path), tmp, utsname()->nodename); if (len > (int)sizeof(nfs_export_path)) goto out_devnametoolong; len = snprintf(nfs_root_device, sizeof(nfs_root_device), "%pI4:%s", &servaddr, nfs_export_path); if (len > (int)sizeof(nfs_root_device)) goto out_devnametoolong; retval = 0; out: kfree(tmp); return retval; out_nomem: printk(KERN_ERR "Root-NFS: could not allocate memory\n"); goto out; out_optionstoolong: printk(KERN_ERR "Root-NFS: mount options string too long\n"); goto out; out_devnametoolong: printk(KERN_ERR "Root-NFS: root device name too long.\n"); goto out; } /** * nfs_root_data - Return prepared 'data' for NFSROOT mount * @root_device: OUT: address of string containing NFSROOT device * @root_data: OUT: address of string containing NFSROOT mount options * * Returns zero and sets @root_device and @root_data if successful, * otherwise -1 is returned. */ int __init nfs_root_data(char **root_device, char **root_data) { #ifdef NFSROOT_DEBUG nfs_debug |= NFSDBG_ROOT | NFSDBG_MOUNT; #endif /* NFSROOT_DEBUG */ servaddr = root_server_addr; if (servaddr == htonl(INADDR_NONE)) { printk(KERN_ERR "Root-NFS: no NFS server address\n"); return -1; } if (root_nfs_data(nfs_root_parms) < 0) return -1; *root_device = nfs_root_device; *root_data = nfs_root_options; return 0; }