/* * 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. */ #ifdef CONFIG_NFS_USE_NEW_IDMAPPER #include <linux/slab.h> #include <linux/cred.h> #include <linux/nfs_idmap.h> #include <linux/keyctl.h> #include <linux/key-type.h> #include <linux/rcupdate.h> #include <linux/kernel.h> #include <linux/err.h> #include <keys/user-type.h> #define NFS_UINT_MAXLEN 11 const struct cred *id_resolver_cache; struct key_type key_type_id_resolver = { .name = "id_resolver", .instantiate = user_instantiate, .match = user_match, .revoke = user_revoke, .destroy = user_destroy, .describe = user_describe, .read = user_read, }; int nfs_idmap_init(void) { struct cred *cred; struct key *keyring; int ret = 0; printk(KERN_NOTICE "Registering the %s key type\n", key_type_id_resolver.name); cred = prepare_kernel_cred(NULL); if (!cred) return -ENOMEM; keyring = key_alloc(&key_type_keyring, ".id_resolver", 0, 0, cred, (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ, KEY_ALLOC_NOT_IN_QUOTA); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto failed_put_cred; } ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL); if (ret < 0) goto failed_put_key; ret = register_key_type(&key_type_id_resolver); if (ret < 0) goto failed_put_key; cred->thread_keyring = keyring; cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING; id_resolver_cache = cred; return 0; failed_put_key: key_put(keyring); failed_put_cred: put_cred(cred); return ret; } void nfs_idmap_quit(void) { key_revoke(id_resolver_cache->thread_keyring); unregister_key_type(&key_type_id_resolver); put_cred(id_resolver_cache); } /* * Assemble the description to pass to request_key() * This function will allocate a new string and update dest to point * at it. The caller is responsible for freeing dest. * * On error 0 is returned. Otherwise, the length of dest is returned. */ static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen, const char *type, size_t typelen, char **desc) { char *cp; size_t desclen = typelen + namelen + 2; *desc = kmalloc(desclen, GFP_KERNEL); if (!*desc) return -ENOMEM; cp = *desc; memcpy(cp, type, typelen); cp += typelen; *cp++ = ':'; memcpy(cp, name, namelen); cp += namelen; *cp = '\0'; return desclen; } static ssize_t nfs_idmap_request_key(const char *name, size_t namelen, const char *type, void *data, size_t data_size) { const struct cred *saved_cred; struct key *rkey; char *desc; struct user_key_payload *payload; ssize_t ret; ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc); if (ret <= 0) goto out; saved_cred = override_creds(id_resolver_cache); rkey = request_key(&key_type_id_resolver, desc, ""); revert_creds(saved_cred); kfree(desc); if (IS_ERR(rkey)) { ret = PTR_ERR(rkey); goto out; } rcu_read_lock(); rkey->perm |= KEY_USR_VIEW; ret = key_validate(rkey); if (ret < 0) goto out_up; payload = rcu_dereference(rkey->payload.data); if (IS_ERR_OR_NULL(payload)) { ret = PTR_ERR(payload); goto out_up; } ret = payload->datalen; if (ret > 0 && ret <= data_size) memcpy(data, payload->data, ret); else ret = -EINVAL; out_up: rcu_read_unlock(); key_put(rkey); out: return ret; } /* ID -> Name */ static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf, size_t buflen) { char id_str[NFS_UINT_MAXLEN]; int id_len; ssize_t ret; id_len = snprintf(id_str, sizeof(id_str), "%u", id); ret = nfs_idmap_request_key(id_str, id_len, type, buf, buflen); if (ret < 0) return -EINVAL; return ret; } /* Name -> ID */ static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type, __u32 *id) { char id_str[NFS_UINT_MAXLEN]; long id_long; ssize_t data_size; int ret = 0; data_size = nfs_idmap_request_key(name, namelen, type, id_str, NFS_UINT_MAXLEN); if (data_size <= 0) { ret = -EINVAL; } else { ret = strict_strtol(id_str, 10, &id_long); *id = (__u32)id_long; } return ret; } int nfs_map_name_to_uid(struct nfs_client *clp, const char *name, size_t namelen, __u32 *uid) { return nfs_idmap_lookup_id(name, namelen, "uid", uid); } int nfs_map_group_to_gid(struct nfs_client *clp, const char *name, size_t namelen, __u32 *gid) { return nfs_idmap_lookup_id(name, namelen, "gid", gid); } int nfs_map_uid_to_name(struct nfs_client *clp, __u32 uid, char *buf, size_t buflen) { return nfs_idmap_lookup_name(uid, "user", buf, buflen); } int nfs_map_gid_to_group(struct nfs_client *clp, __u32 gid, char *buf, size_t buflen) { return nfs_idmap_lookup_name(gid, "group", buf, buflen); } #else /* CONFIG_NFS_USE_IDMAPPER not defined */ #include <linux/module.h> #include <linux/mutex.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.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; static int param_set_idmap_timeout(const char *val, struct kernel_param *kp) { char *endp; int num = simple_strtol(val, &endp, 0); int jif = num * HZ; if (endp == val || *endp || num < 0 || jif < num) return -EINVAL; *((int *)kp->arg) = jif; return 0; } module_param_call(idmap_cache_timeout, param_set_idmap_timeout, param_get_int, &nfs_idmap_cache_timeout, 0644); struct idmap_hashent { unsigned long ih_expires; __u32 ih_id; size_t ih_namelen; char ih_name[IDMAP_NAMESZ]; }; struct idmap_hashtable { __u8 h_type; struct idmap_hashent h_entries[IDMAP_HASH_SZ]; }; struct idmap { struct dentry *idmap_dentry; wait_queue_head_t idmap_wq; struct idmap_msg idmap_im; struct mutex idmap_lock; /* Serializes upcalls */ struct mutex 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 const struct rpc_pipe_ops idmap_upcall_ops = { .upcall = idmap_pipe_upcall, .downcall = idmap_pipe_downcall, .destroy_msg = idmap_pipe_destroy_msg, }; int nfs_idmap_new(struct nfs_client *clp) { struct idmap *idmap; int error; BUG_ON(clp->cl_idmap != NULL); idmap = kzalloc(sizeof(*idmap), GFP_KERNEL); if (idmap == NULL) return -ENOMEM; idmap->idmap_dentry = rpc_mkpipe(clp->cl_rpcclient->cl_path.dentry, "idmap", idmap, &idmap_upcall_ops, 0); if (IS_ERR(idmap->idmap_dentry)) { error = PTR_ERR(idmap->idmap_dentry); kfree(idmap); return error; } mutex_init(&idmap->idmap_lock); mutex_init(&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; return 0; } void nfs_idmap_delete(struct nfs_client *clp) { struct idmap *idmap = clp->cl_idmap; if (!idmap) return; rpc_unlink(idmap->idmap_dentry); 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, size_t 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; mutex_lock(&idmap->idmap_lock); mutex_lock(&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); mutex_unlock(&idmap->idmap_im_lock); schedule(); __set_current_state(TASK_RUNNING); remove_wait_queue(&idmap->idmap_wq, &wq); mutex_lock(&idmap->idmap_im_lock); if (im->im_status & IDMAP_STATUS_SUCCESS) { *id = im->im_id; ret = 0; } out: memset(im, 0, sizeof(*im)); mutex_unlock(&idmap->idmap_im_lock); mutex_unlock(&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; mutex_lock(&idmap->idmap_lock); mutex_lock(&idmap->idmap_im_lock); he = idmap_lookup_id(h, id); if (he) { 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); mutex_unlock(&idmap->idmap_im_lock); schedule(); __set_current_state(TASK_RUNNING); remove_wait_queue(&idmap->idmap_wq, &wq); mutex_lock(&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)); mutex_unlock(&idmap->idmap_im_lock); mutex_unlock(&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; size_t mlen = min(msg->len, buflen); unsigned long left; left = copy_to_user(dst, data, mlen); if (left == mlen) { msg->errno = -EFAULT; return -EFAULT; } 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_path.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; size_t namelen_in; int ret; if (mlen != sizeof(im_in)) return -ENOSPC; if (copy_from_user(&im_in, src, mlen) != 0) return -EFAULT; mutex_lock(&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: mutex_unlock(&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; mutex_lock(&idmap->idmap_im_lock); im->im_status = IDMAP_STATUS_LOOKUPFAIL; wake_up(&idmap->idmap_wq); mutex_unlock(&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 nfs_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 nfs_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 nfs_client *clp, __u32 uid, char *buf, size_t buflen) { struct idmap *idmap = clp->cl_idmap; return nfs_idmap_name(idmap, &idmap->idmap_user_hash, uid, buf); } int nfs_map_gid_to_group(struct nfs_client *clp, __u32 uid, char *buf, size_t buflen) { struct idmap *idmap = clp->cl_idmap; return nfs_idmap_name(idmap, &idmap->idmap_group_hash, uid, buf); } #endif /* CONFIG_NFS_USE_NEW_IDMAPPER */