/*
* Copyright (C) 1995, 1996 Gero Kuhlmann <gero@gkminix.han.de>
*
* 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 <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/xprtsock.h>
#include <linux/nfs.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_mount.h>
#include <linux/in.h>
#include <linux/major.h>
#include <linux/utsname.h>
#include <linux/inet.h>
#include <linux/root_dev.h>
#include <net/ipconfig.h>
#include <linux/parser.h>
#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=[<server-ip>:]<root-dir>[,<nfs-options>]
*
* If there is a "%s" token in the <root-dir> 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;
}
