/* * 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; 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); }