--- /dev/null
+/*
+ * 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"
+
+#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
+ * @fspath - fs path returned in fs_locations
+ * @mntpath - mount path to new server
+ * @hostname - hostname of new server
+ * @addr - host addr of new server
+ *
+ */
+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;
+ char *devname;
+ int loc, s, 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;
+ }
+
+ devname = nfs_devname(mnt_parent, dentry, page, PAGE_SIZE);
+ if (IS_ERR(devname)) {
+ mnt = (struct vfsmount *)devname;
+ 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 = {};
+
+ 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);
+ addr.sin_family = AF_INET;
+ addr.sin_port = htons(NFS_PORT);
+ mountdata.addr = &addr;
+
+ mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, devname, &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, 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;
+}
git://git.onelab.eu / linux-2.6.git / blobdiff