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-rw-r--r--fs/nfs/idmap.c498
1 files changed, 498 insertions, 0 deletions
diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
new file mode 100644
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--- /dev/null
+++ b/fs/nfs/idmap.c
@@ -0,0 +1,498 @@
+/*
+ * fs/nfs/idmap.c
+ *
+ * UID and GID to name mapping for clients.
+ *
+ * Copyright (c) 2002 The Regents of the University of Michigan.
+ * All rights reserved.
+ *
+ * Marius Aamodt Eriksen <marius@umich.edu>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/sched.h>
+
+#include <linux/sunrpc/clnt.h>
+#include <linux/workqueue.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
+
+#include <linux/nfs_fs_sb.h>
+#include <linux/nfs_fs.h>
+
+#include <linux/nfs_idmap.h>
+
+#define IDMAP_HASH_SZ 128
+
+struct idmap_hashent {
+ __u32 ih_id;
+ int ih_namelen;
+ char ih_name[IDMAP_NAMESZ];
+};
+
+struct idmap_hashtable {
+ __u8 h_type;
+ struct idmap_hashent h_entries[IDMAP_HASH_SZ];
+};
+
+struct idmap {
+ char idmap_path[48];
+ struct dentry *idmap_dentry;
+ wait_queue_head_t idmap_wq;
+ struct idmap_msg idmap_im;
+ struct semaphore idmap_lock; /* Serializes upcalls */
+ struct semaphore idmap_im_lock; /* Protects the hashtable */
+ struct idmap_hashtable idmap_user_hash;
+ struct idmap_hashtable idmap_group_hash;
+};
+
+static ssize_t idmap_pipe_upcall(struct file *, struct rpc_pipe_msg *,
+ char __user *, size_t);
+static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
+ size_t);
+void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
+
+static unsigned int fnvhash32(const void *, size_t);
+
+static struct rpc_pipe_ops idmap_upcall_ops = {
+ .upcall = idmap_pipe_upcall,
+ .downcall = idmap_pipe_downcall,
+ .destroy_msg = idmap_pipe_destroy_msg,
+};
+
+void
+nfs_idmap_new(struct nfs4_client *clp)
+{
+ struct idmap *idmap;
+
+ if (clp->cl_idmap != NULL)
+ return;
+ if ((idmap = kmalloc(sizeof(*idmap), GFP_KERNEL)) == NULL)
+ return;
+
+ memset(idmap, 0, sizeof(*idmap));
+
+ snprintf(idmap->idmap_path, sizeof(idmap->idmap_path),
+ "%s/idmap", clp->cl_rpcclient->cl_pathname);
+
+ idmap->idmap_dentry = rpc_mkpipe(idmap->idmap_path,
+ idmap, &idmap_upcall_ops, 0);
+ if (IS_ERR(idmap->idmap_dentry)) {
+ kfree(idmap);
+ return;
+ }
+
+ init_MUTEX(&idmap->idmap_lock);
+ init_MUTEX(&idmap->idmap_im_lock);
+ init_waitqueue_head(&idmap->idmap_wq);
+ idmap->idmap_user_hash.h_type = IDMAP_TYPE_USER;
+ idmap->idmap_group_hash.h_type = IDMAP_TYPE_GROUP;
+
+ clp->cl_idmap = idmap;
+}
+
+void
+nfs_idmap_delete(struct nfs4_client *clp)
+{
+ struct idmap *idmap = clp->cl_idmap;
+
+ if (!idmap)
+ return;
+ rpc_unlink(idmap->idmap_path);
+ clp->cl_idmap = NULL;
+ kfree(idmap);
+}
+
+/*
+ * Helper routines for manipulating the hashtable
+ */
+static inline struct idmap_hashent *
+idmap_name_hash(struct idmap_hashtable* h, const char *name, size_t len)
+{
+ return &h->h_entries[fnvhash32(name, len) % IDMAP_HASH_SZ];
+}
+
+static struct idmap_hashent *
+idmap_lookup_name(struct idmap_hashtable *h, const char *name, size_t len)
+{
+ struct idmap_hashent *he = idmap_name_hash(h, name, len);
+
+ if (he->ih_namelen != len || memcmp(he->ih_name, name, len) != 0)
+ return NULL;
+ return he;
+}
+
+static inline struct idmap_hashent *
+idmap_id_hash(struct idmap_hashtable* h, __u32 id)
+{
+ return &h->h_entries[fnvhash32(&id, sizeof(id)) % IDMAP_HASH_SZ];
+}
+
+static struct idmap_hashent *
+idmap_lookup_id(struct idmap_hashtable *h, __u32 id)
+{
+ struct idmap_hashent *he = idmap_id_hash(h, id);
+ if (he->ih_id != id || he->ih_namelen == 0)
+ return NULL;
+ return he;
+}
+
+/*
+ * Routines for allocating new entries in the hashtable.
+ * For now, we just have 1 entry per bucket, so it's all
+ * pretty trivial.
+ */
+static inline struct idmap_hashent *
+idmap_alloc_name(struct idmap_hashtable *h, char *name, unsigned len)
+{
+ return idmap_name_hash(h, name, len);
+}
+
+static inline struct idmap_hashent *
+idmap_alloc_id(struct idmap_hashtable *h, __u32 id)
+{
+ return idmap_id_hash(h, id);
+}
+
+static void
+idmap_update_entry(struct idmap_hashent *he, const char *name,
+ size_t namelen, __u32 id)
+{
+ he->ih_id = id;
+ memcpy(he->ih_name, name, namelen);
+ he->ih_name[namelen] = '\0';
+ he->ih_namelen = namelen;
+}
+
+/*
+ * Name -> ID
+ */
+static int
+nfs_idmap_id(struct idmap *idmap, struct idmap_hashtable *h,
+ const char *name, size_t namelen, __u32 *id)
+{
+ struct rpc_pipe_msg msg;
+ struct idmap_msg *im;
+ struct idmap_hashent *he;
+ DECLARE_WAITQUEUE(wq, current);
+ int ret = -EIO;
+
+ im = &idmap->idmap_im;
+
+ /*
+ * String sanity checks
+ * Note that the userland daemon expects NUL terminated strings
+ */
+ for (;;) {
+ if (namelen == 0)
+ return -EINVAL;
+ if (name[namelen-1] != '\0')
+ break;
+ namelen--;
+ }
+ if (namelen >= IDMAP_NAMESZ)
+ return -EINVAL;
+
+ down(&idmap->idmap_lock);
+ down(&idmap->idmap_im_lock);
+
+ he = idmap_lookup_name(h, name, namelen);
+ if (he != NULL) {
+ *id = he->ih_id;
+ ret = 0;
+ goto out;
+ }
+
+ memset(im, 0, sizeof(*im));
+ memcpy(im->im_name, name, namelen);
+
+ im->im_type = h->h_type;
+ im->im_conv = IDMAP_CONV_NAMETOID;
+
+ memset(&msg, 0, sizeof(msg));
+ msg.data = im;
+ msg.len = sizeof(*im);
+
+ add_wait_queue(&idmap->idmap_wq, &wq);
+ if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
+ remove_wait_queue(&idmap->idmap_wq, &wq);
+ goto out;
+ }
+
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ up(&idmap->idmap_im_lock);
+ schedule();
+ current->state = TASK_RUNNING;
+ remove_wait_queue(&idmap->idmap_wq, &wq);
+ down(&idmap->idmap_im_lock);
+
+ if (im->im_status & IDMAP_STATUS_SUCCESS) {
+ *id = im->im_id;
+ ret = 0;
+ }
+
+ out:
+ memset(im, 0, sizeof(*im));
+ up(&idmap->idmap_im_lock);
+ up(&idmap->idmap_lock);
+ return (ret);
+}
+
+/*
+ * ID -> Name
+ */
+static int
+nfs_idmap_name(struct idmap *idmap, struct idmap_hashtable *h,
+ __u32 id, char *name)
+{
+ struct rpc_pipe_msg msg;
+ struct idmap_msg *im;
+ struct idmap_hashent *he;
+ DECLARE_WAITQUEUE(wq, current);
+ int ret = -EIO;
+ unsigned int len;
+
+ im = &idmap->idmap_im;
+
+ down(&idmap->idmap_lock);
+ down(&idmap->idmap_im_lock);
+
+ he = idmap_lookup_id(h, id);
+ if (he != 0) {
+ memcpy(name, he->ih_name, he->ih_namelen);
+ ret = he->ih_namelen;
+ goto out;
+ }
+
+ memset(im, 0, sizeof(*im));
+ im->im_type = h->h_type;
+ im->im_conv = IDMAP_CONV_IDTONAME;
+ im->im_id = id;
+
+ memset(&msg, 0, sizeof(msg));
+ msg.data = im;
+ msg.len = sizeof(*im);
+
+ add_wait_queue(&idmap->idmap_wq, &wq);
+
+ if (rpc_queue_upcall(idmap->idmap_dentry->d_inode, &msg) < 0) {
+ remove_wait_queue(&idmap->idmap_wq, &wq);
+ goto out;
+ }
+
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ up(&idmap->idmap_im_lock);
+ schedule();
+ current->state = TASK_RUNNING;
+ remove_wait_queue(&idmap->idmap_wq, &wq);
+ down(&idmap->idmap_im_lock);
+
+ if (im->im_status & IDMAP_STATUS_SUCCESS) {
+ if ((len = strnlen(im->im_name, IDMAP_NAMESZ)) == 0)
+ goto out;
+ memcpy(name, im->im_name, len);
+ ret = len;
+ }
+
+ out:
+ memset(im, 0, sizeof(*im));
+ up(&idmap->idmap_im_lock);
+ up(&idmap->idmap_lock);
+ return ret;
+}
+
+/* RPC pipefs upcall/downcall routines */
+static ssize_t
+idmap_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
+ char __user *dst, size_t buflen)
+{
+ char *data = (char *)msg->data + msg->copied;
+ ssize_t mlen = msg->len - msg->copied;
+ ssize_t left;
+
+ if (mlen > buflen)
+ mlen = buflen;
+
+ left = copy_to_user(dst, data, mlen);
+ if (left < 0) {
+ msg->errno = left;
+ return left;
+ }
+ mlen -= left;
+ msg->copied += mlen;
+ msg->errno = 0;
+ return mlen;
+}
+
+static ssize_t
+idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
+{
+ struct rpc_inode *rpci = RPC_I(filp->f_dentry->d_inode);
+ struct idmap *idmap = (struct idmap *)rpci->private;
+ struct idmap_msg im_in, *im = &idmap->idmap_im;
+ struct idmap_hashtable *h;
+ struct idmap_hashent *he = NULL;
+ int namelen_in;
+ int ret;
+
+ if (mlen != sizeof(im_in))
+ return (-ENOSPC);
+
+ if (copy_from_user(&im_in, src, mlen) != 0)
+ return (-EFAULT);
+
+ down(&idmap->idmap_im_lock);
+
+ ret = mlen;
+ im->im_status = im_in.im_status;
+ /* If we got an error, terminate now, and wake up pending upcalls */
+ if (!(im_in.im_status & IDMAP_STATUS_SUCCESS)) {
+ wake_up(&idmap->idmap_wq);
+ goto out;
+ }
+
+ /* Sanity checking of strings */
+ ret = -EINVAL;
+ namelen_in = strnlen(im_in.im_name, IDMAP_NAMESZ);
+ if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ)
+ goto out;
+
+ switch (im_in.im_type) {
+ case IDMAP_TYPE_USER:
+ h = &idmap->idmap_user_hash;
+ break;
+ case IDMAP_TYPE_GROUP:
+ h = &idmap->idmap_group_hash;
+ break;
+ default:
+ goto out;
+ }
+
+ switch (im_in.im_conv) {
+ case IDMAP_CONV_IDTONAME:
+ /* Did we match the current upcall? */
+ if (im->im_conv == IDMAP_CONV_IDTONAME
+ && im->im_type == im_in.im_type
+ && im->im_id == im_in.im_id) {
+ /* Yes: copy string, including the terminating '\0' */
+ memcpy(im->im_name, im_in.im_name, namelen_in);
+ im->im_name[namelen_in] = '\0';
+ wake_up(&idmap->idmap_wq);
+ }
+ he = idmap_alloc_id(h, im_in.im_id);
+ break;
+ case IDMAP_CONV_NAMETOID:
+ /* Did we match the current upcall? */
+ if (im->im_conv == IDMAP_CONV_NAMETOID
+ && im->im_type == im_in.im_type
+ && strnlen(im->im_name, IDMAP_NAMESZ) == namelen_in
+ && memcmp(im->im_name, im_in.im_name, namelen_in) == 0) {
+ im->im_id = im_in.im_id;
+ wake_up(&idmap->idmap_wq);
+ }
+ he = idmap_alloc_name(h, im_in.im_name, namelen_in);
+ break;
+ default:
+ goto out;
+ }
+
+ /* If the entry is valid, also copy it to the cache */
+ if (he != NULL)
+ idmap_update_entry(he, im_in.im_name, namelen_in, im_in.im_id);
+ ret = mlen;
+out:
+ up(&idmap->idmap_im_lock);
+ return ret;
+}
+
+void
+idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
+{
+ struct idmap_msg *im = msg->data;
+ struct idmap *idmap = container_of(im, struct idmap, idmap_im);
+
+ if (msg->errno >= 0)
+ return;
+ down(&idmap->idmap_im_lock);
+ im->im_status = IDMAP_STATUS_LOOKUPFAIL;
+ wake_up(&idmap->idmap_wq);
+ up(&idmap->idmap_im_lock);
+}
+
+/*
+ * Fowler/Noll/Vo hash
+ * http://www.isthe.com/chongo/tech/comp/fnv/
+ */
+
+#define FNV_P_32 ((unsigned int)0x01000193) /* 16777619 */
+#define FNV_1_32 ((unsigned int)0x811c9dc5) /* 2166136261 */
+
+static unsigned int fnvhash32(const void *buf, size_t buflen)
+{
+ const unsigned char *p, *end = (const unsigned char *)buf + buflen;
+ unsigned int hash = FNV_1_32;
+
+ for (p = buf; p < end; p++) {
+ hash *= FNV_P_32;
+ hash ^= (unsigned int)*p;
+ }
+
+ return (hash);
+}
+
+int nfs_map_name_to_uid(struct nfs4_client *clp, const char *name, size_t namelen, __u32 *uid)
+{
+ struct idmap *idmap = clp->cl_idmap;
+
+ return nfs_idmap_id(idmap, &idmap->idmap_user_hash, name, namelen, uid);
+}
+
+int nfs_map_group_to_gid(struct nfs4_client *clp, const char *name, size_t namelen, __u32 *uid)
+{
+ struct idmap *idmap = clp->cl_idmap;
+
+ return nfs_idmap_id(idmap, &idmap->idmap_group_hash, name, namelen, uid);
+}
+
+int nfs_map_uid_to_name(struct nfs4_client *clp, __u32 uid, char *buf)
+{
+ struct idmap *idmap = clp->cl_idmap;
+
+ return nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf);
+}
+int nfs_map_gid_to_group(struct nfs4_client *clp, __u32 uid, char *buf)
+{
+ struct idmap *idmap = clp->cl_idmap;
+
+ return nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf);
+}
+
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