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/*
* $Id: nfsroot.c,v 1.45 1998/03/07 10:44:46 mj Exp $
*
* 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) 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 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.
*/
#include <linux/config.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_mount.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/major.h>
#include <linux/utsname.h>
#include <net/ipconfig.h>
/* 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;
}
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