| /* |
| * 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> |
| #include "nfs4_fs.h" |
| |
| #define IDMAP_HASH_SZ 128 |
| |
| /* Default cache timeout is 10 minutes */ |
| unsigned int nfs_idmap_cache_timeout = 600 * HZ; |
| |
| struct idmap_hashent { |
| unsigned long ih_expires; |
| __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); |
| static 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; |
| dput(idmap->idmap_dentry); |
| idmap->idmap_dentry = NULL; |
| 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; |
| if (time_after(jiffies, he->ih_expires)) |
| 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; |
| if (time_after(jiffies, he->ih_expires)) |
| 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; |
| he->ih_expires = jiffies + nfs_idmap_cache_timeout; |
| } |
| |
| /* |
| * 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; |
| } |
| |
| static 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); |
| } |
| |