kernel-ark/fs/nfs/nfs4namespace.c
Chuck Lever 6677d09513 NFS: Adjust nfs_clone_mount structure to store "struct sockaddr *"
Change the addr field in the nfs_clone_mount structure to store a "struct
sockaddr *" to support non-IPv4 addresses in the NFS client.

Note this is mostly a cosmetic change, and does not actually allow
referrals using IPv6 addresses.  The existing referral code assumes that
the server returns a string that represents an IPv4 address.  This code
needs to support hostnames and IPv6 addresses as well as IPv4 addresses,
thus it will need to be reorganized completely (to handle DNS resolution
in user space).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-30 02:05:56 -05:00

258 lines
6.0 KiB
C

/*
* linux/fs/nfs/nfs4namespace.c
*
* Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
* - Modified by David Howells <dhowells@redhat.com>
*
* NFSv4 namespace
*/
#include <linux/dcache.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/nfs_fs.h>
#include <linux/string.h>
#include <linux/sunrpc/clnt.h>
#include <linux/vfs.h>
#include <linux/inet.h>
#include "internal.h"
#include "nfs4_fs.h"
#define NFSDBG_FACILITY NFSDBG_VFS
/*
* Check if fs_root is valid
*/
static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
char *buffer, ssize_t buflen)
{
char *end = buffer + buflen;
int n;
*--end = '\0';
buflen--;
n = pathname->ncomponents;
while (--n >= 0) {
const struct nfs4_string *component = &pathname->components[n];
buflen -= component->len + 1;
if (buflen < 0)
goto Elong;
end -= component->len;
memcpy(end, component->data, component->len);
*--end = '/';
}
return end;
Elong:
return ERR_PTR(-ENAMETOOLONG);
}
/*
* Determine the mount path as a string
*/
static char *nfs4_path(const struct vfsmount *mnt_parent,
const struct dentry *dentry,
char *buffer, ssize_t buflen)
{
const char *srvpath;
srvpath = strchr(mnt_parent->mnt_devname, ':');
if (srvpath)
srvpath++;
else
srvpath = mnt_parent->mnt_devname;
return nfs_path(srvpath, mnt_parent->mnt_root, dentry, buffer, buflen);
}
/*
* Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
* believe to be the server path to this dentry
*/
static int nfs4_validate_fspath(const struct vfsmount *mnt_parent,
const struct dentry *dentry,
const struct nfs4_fs_locations *locations,
char *page, char *page2)
{
const char *path, *fs_path;
path = nfs4_path(mnt_parent, dentry, page, PAGE_SIZE);
if (IS_ERR(path))
return PTR_ERR(path);
fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
if (IS_ERR(fs_path))
return PTR_ERR(fs_path);
if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
dprintk("%s: path %s does not begin with fsroot %s\n",
__FUNCTION__, path, fs_path);
return -ENOENT;
}
return 0;
}
/*
* Check if the string represents a "valid" IPv4 address
*/
static inline int valid_ipaddr4(const char *buf)
{
int rc, count, in[4];
rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
if (rc != 4)
return -EINVAL;
for (count = 0; count < 4; count++) {
if (in[count] > 255)
return -EINVAL;
}
return 0;
}
/**
* nfs_follow_referral - set up mountpoint when hitting a referral on moved error
* @mnt_parent - mountpoint of parent directory
* @dentry - parent directory
* @locations - array of NFSv4 server location information
*
*/
static struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent,
const struct dentry *dentry,
const struct nfs4_fs_locations *locations)
{
struct vfsmount *mnt = ERR_PTR(-ENOENT);
struct nfs_clone_mount mountdata = {
.sb = mnt_parent->mnt_sb,
.dentry = dentry,
.authflavor = NFS_SB(mnt_parent->mnt_sb)->client->cl_auth->au_flavor,
};
char *page = NULL, *page2 = NULL;
unsigned int s;
int loc, error;
if (locations == NULL || locations->nlocations <= 0)
goto out;
dprintk("%s: referral at %s/%s\n", __FUNCTION__,
dentry->d_parent->d_name.name, dentry->d_name.name);
page = (char *) __get_free_page(GFP_USER);
if (!page)
goto out;
page2 = (char *) __get_free_page(GFP_USER);
if (!page2)
goto out;
/* Ensure fs path is a prefix of current dentry path */
error = nfs4_validate_fspath(mnt_parent, dentry, locations, page, page2);
if (error < 0) {
mnt = ERR_PTR(error);
goto out;
}
loc = 0;
while (loc < locations->nlocations && IS_ERR(mnt)) {
const struct nfs4_fs_location *location = &locations->locations[loc];
char *mnt_path;
if (location == NULL || location->nservers <= 0 ||
location->rootpath.ncomponents == 0) {
loc++;
continue;
}
mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
if (IS_ERR(mnt_path)) {
loc++;
continue;
}
mountdata.mnt_path = mnt_path;
s = 0;
while (s < location->nservers) {
struct sockaddr_in addr = {
.sin_family = AF_INET,
.sin_port = htons(NFS_PORT),
};
if (location->servers[s].len <= 0 ||
valid_ipaddr4(location->servers[s].data) < 0) {
s++;
continue;
}
mountdata.hostname = location->servers[s].data;
addr.sin_addr.s_addr = in_aton(mountdata.hostname),
mountdata.addr = (struct sockaddr *)&addr;
mountdata.addrlen = sizeof(addr);
snprintf(page, PAGE_SIZE, "%s:%s",
mountdata.hostname,
mountdata.mnt_path);
mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, &mountdata);
if (!IS_ERR(mnt)) {
break;
}
s++;
}
loc++;
}
out:
free_page((unsigned long) page);
free_page((unsigned long) page2);
dprintk("%s: done\n", __FUNCTION__);
return mnt;
}
/*
* nfs_do_refmount - handle crossing a referral on server
* @dentry - dentry of referral
* @nd - nameidata info
*
*/
struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry)
{
struct vfsmount *mnt = ERR_PTR(-ENOMEM);
struct dentry *parent;
struct nfs4_fs_locations *fs_locations = NULL;
struct page *page;
int err;
/* BUG_ON(IS_ROOT(dentry)); */
dprintk("%s: enter\n", __FUNCTION__);
page = alloc_page(GFP_KERNEL);
if (page == NULL)
goto out;
fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
if (fs_locations == NULL)
goto out_free;
/* Get locations */
mnt = ERR_PTR(-ENOENT);
parent = dget_parent(dentry);
dprintk("%s: getting locations for %s/%s\n",
__FUNCTION__, parent->d_name.name, dentry->d_name.name);
err = nfs4_proc_fs_locations(parent->d_inode, &dentry->d_name, fs_locations, page);
dput(parent);
if (err != 0 ||
fs_locations->nlocations <= 0 ||
fs_locations->fs_path.ncomponents <= 0)
goto out_free;
mnt = nfs_follow_referral(mnt_parent, dentry, fs_locations);
out_free:
__free_page(page);
kfree(fs_locations);
out:
dprintk("%s: done\n", __FUNCTION__);
return mnt;
}