// SPDX-License-Identifier: GPL-2.0-only /* * net/sunrpc/rpc_pipe.c * * Userland/kernel interface for rpcauth_gss. * Code shamelessly plagiarized from fs/nfsd/nfsctl.c * and fs/sysfs/inode.c * * Copyright (c) 2002, Trond Myklebust * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "netns.h" #include "sunrpc.h" #define RPCDBG_FACILITY RPCDBG_DEBUG #define NET_NAME(net) ((net == &init_net) ? " (init_net)" : "") static struct file_system_type rpc_pipe_fs_type; static const struct rpc_pipe_ops gssd_dummy_pipe_ops; static struct kmem_cache *rpc_inode_cachep __read_mostly; #define RPC_UPCALL_TIMEOUT (30*HZ) static BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list); int rpc_pipefs_notifier_register(struct notifier_block *nb) { return blocking_notifier_chain_cond_register(&rpc_pipefs_notifier_list, nb); } EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register); void rpc_pipefs_notifier_unregister(struct notifier_block *nb) { blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb); } EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister); static void rpc_purge_list(wait_queue_head_t *waitq, struct list_head *head, void (*destroy_msg)(struct rpc_pipe_msg *), int err) { struct rpc_pipe_msg *msg; if (list_empty(head)) return; do { msg = list_entry(head->next, struct rpc_pipe_msg, list); list_del_init(&msg->list); msg->errno = err; destroy_msg(msg); } while (!list_empty(head)); if (waitq) wake_up(waitq); } static void rpc_timeout_upcall_queue(struct work_struct *work) { LIST_HEAD(free_list); struct rpc_pipe *pipe = container_of(work, struct rpc_pipe, queue_timeout.work); void (*destroy_msg)(struct rpc_pipe_msg *); struct dentry *dentry; spin_lock(&pipe->lock); destroy_msg = pipe->ops->destroy_msg; if (pipe->nreaders == 0) { list_splice_init(&pipe->pipe, &free_list); pipe->pipelen = 0; } dentry = dget(pipe->dentry); spin_unlock(&pipe->lock); rpc_purge_list(dentry ? &RPC_I(d_inode(dentry))->waitq : NULL, &free_list, destroy_msg, -ETIMEDOUT); dput(dentry); } ssize_t rpc_pipe_generic_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 - msg->copied, 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; } EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall); /** * rpc_queue_upcall - queue an upcall message to userspace * @pipe: upcall pipe on which to queue given message * @msg: message to queue * * Call with an @inode created by rpc_mkpipe() to queue an upcall. * A userspace process may then later read the upcall by performing a * read on an open file for this inode. It is up to the caller to * initialize the fields of @msg (other than @msg->list) appropriately. */ int rpc_queue_upcall(struct rpc_pipe *pipe, struct rpc_pipe_msg *msg) { int res = -EPIPE; struct dentry *dentry; spin_lock(&pipe->lock); if (pipe->nreaders) { list_add_tail(&msg->list, &pipe->pipe); pipe->pipelen += msg->len; res = 0; } else if (pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) { if (list_empty(&pipe->pipe)) queue_delayed_work(rpciod_workqueue, &pipe->queue_timeout, RPC_UPCALL_TIMEOUT); list_add_tail(&msg->list, &pipe->pipe); pipe->pipelen += msg->len; res = 0; } dentry = dget(pipe->dentry); spin_unlock(&pipe->lock); if (dentry) { wake_up(&RPC_I(d_inode(dentry))->waitq); dput(dentry); } return res; } EXPORT_SYMBOL_GPL(rpc_queue_upcall); static inline void rpc_inode_setowner(struct inode *inode, void *private) { RPC_I(inode)->private = private; } static void rpc_close_pipes(struct inode *inode) { struct rpc_pipe *pipe = RPC_I(inode)->pipe; int need_release; LIST_HEAD(free_list); inode_lock(inode); spin_lock(&pipe->lock); need_release = pipe->nreaders != 0 || pipe->nwriters != 0; pipe->nreaders = 0; list_splice_init(&pipe->in_upcall, &free_list); list_splice_init(&pipe->pipe, &free_list); pipe->pipelen = 0; pipe->dentry = NULL; spin_unlock(&pipe->lock); rpc_purge_list(&RPC_I(inode)->waitq, &free_list, pipe->ops->destroy_msg, -EPIPE); pipe->nwriters = 0; if (need_release && pipe->ops->release_pipe) pipe->ops->release_pipe(inode); cancel_delayed_work_sync(&pipe->queue_timeout); rpc_inode_setowner(inode, NULL); RPC_I(inode)->pipe = NULL; inode_unlock(inode); } static struct inode * rpc_alloc_inode(struct super_block *sb) { struct rpc_inode *rpci; rpci = kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL); if (!rpci) return NULL; return &rpci->vfs_inode; } static void rpc_free_inode(struct inode *inode) { kmem_cache_free(rpc_inode_cachep, RPC_I(inode)); } static int rpc_pipe_open(struct inode *inode, struct file *filp) { struct rpc_pipe *pipe; int first_open; int res = -ENXIO; inode_lock(inode); pipe = RPC_I(inode)->pipe; if (pipe == NULL) goto out; first_open = pipe->nreaders == 0 && pipe->nwriters == 0; if (first_open && pipe->ops->open_pipe) { res = pipe->ops->open_pipe(inode); if (res) goto out; } if (filp->f_mode & FMODE_READ) pipe->nreaders++; if (filp->f_mode & FMODE_WRITE) pipe->nwriters++; res = 0; out: inode_unlock(inode); return res; } static int rpc_pipe_release(struct inode *inode, struct file *filp) { struct rpc_pipe *pipe; struct rpc_pipe_msg *msg; int last_close; inode_lock(inode); pipe = RPC_I(inode)->pipe; if (pipe == NULL) goto out; msg = filp->private_data; if (msg != NULL) { spin_lock(&pipe->lock); msg->errno = -EAGAIN; list_del_init(&msg->list); spin_unlock(&pipe->lock); pipe->ops->destroy_msg(msg); } if (filp->f_mode & FMODE_WRITE) pipe->nwriters --; if (filp->f_mode & FMODE_READ) { pipe->nreaders --; if (pipe->nreaders == 0) { LIST_HEAD(free_list); spin_lock(&pipe->lock); list_splice_init(&pipe->pipe, &free_list); pipe->pipelen = 0; spin_unlock(&pipe->lock); rpc_purge_list(&RPC_I(inode)->waitq, &free_list, pipe->ops->destroy_msg, -EAGAIN); } } last_close = pipe->nwriters == 0 && pipe->nreaders == 0; if (last_close && pipe->ops->release_pipe) pipe->ops->release_pipe(inode); out: inode_unlock(inode); return 0; } static ssize_t rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset) { struct inode *inode = file_inode(filp); struct rpc_pipe *pipe; struct rpc_pipe_msg *msg; int res = 0; inode_lock(inode); pipe = RPC_I(inode)->pipe; if (pipe == NULL) { res = -EPIPE; goto out_unlock; } msg = filp->private_data; if (msg == NULL) { spin_lock(&pipe->lock); if (!list_empty(&pipe->pipe)) { msg = list_entry(pipe->pipe.next, struct rpc_pipe_msg, list); list_move(&msg->list, &pipe->in_upcall); pipe->pipelen -= msg->len; filp->private_data = msg; msg->copied = 0; } spin_unlock(&pipe->lock); if (msg == NULL) goto out_unlock; } /* NOTE: it is up to the callback to update msg->copied */ res = pipe->ops->upcall(filp, msg, buf, len); if (res < 0 || msg->len == msg->copied) { filp->private_data = NULL; spin_lock(&pipe->lock); list_del_init(&msg->list); spin_unlock(&pipe->lock); pipe->ops->destroy_msg(msg); } out_unlock: inode_unlock(inode); return res; } static ssize_t rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset) { struct inode *inode = file_inode(filp); int res; inode_lock(inode); res = -EPIPE; if (RPC_I(inode)->pipe != NULL) res = RPC_I(inode)->pipe->ops->downcall(filp, buf, len); inode_unlock(inode); return res; } static __poll_t rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait) { struct inode *inode = file_inode(filp); struct rpc_inode *rpci = RPC_I(inode); __poll_t mask = EPOLLOUT | EPOLLWRNORM; poll_wait(filp, &rpci->waitq, wait); inode_lock(inode); if (rpci->pipe == NULL) mask |= EPOLLERR | EPOLLHUP; else if (filp->private_data || !list_empty(&rpci->pipe->pipe)) mask |= EPOLLIN | EPOLLRDNORM; inode_unlock(inode); return mask; } static long rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct inode *inode = file_inode(filp); struct rpc_pipe *pipe; int len; switch (cmd) { case FIONREAD: inode_lock(inode); pipe = RPC_I(inode)->pipe; if (pipe == NULL) { inode_unlock(inode); return -EPIPE; } spin_lock(&pipe->lock); len = pipe->pipelen; if (filp->private_data) { struct rpc_pipe_msg *msg; msg = filp->private_data; len += msg->len - msg->copied; } spin_unlock(&pipe->lock); inode_unlock(inode); return put_user(len, (int __user *)arg); default: return -EINVAL; } } static const struct file_operations rpc_pipe_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .read = rpc_pipe_read, .write = rpc_pipe_write, .poll = rpc_pipe_poll, .unlocked_ioctl = rpc_pipe_ioctl, .open = rpc_pipe_open, .release = rpc_pipe_release, }; static int rpc_show_info(struct seq_file *m, void *v) { struct rpc_clnt *clnt = m->private; rcu_read_lock(); seq_printf(m, "RPC server: %s\n", rcu_dereference(clnt->cl_xprt)->servername); seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_program->name, clnt->cl_prog, clnt->cl_vers); seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR)); seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO)); seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT)); rcu_read_unlock(); return 0; } static int rpc_info_open(struct inode *inode, struct file *file) { struct rpc_clnt *clnt = NULL; int ret = single_open(file, rpc_show_info, NULL); if (!ret) { struct seq_file *m = file->private_data; spin_lock(&file->f_path.dentry->d_lock); if (!d_unhashed(file->f_path.dentry)) clnt = RPC_I(inode)->private; if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) { spin_unlock(&file->f_path.dentry->d_lock); m->private = clnt; } else { spin_unlock(&file->f_path.dentry->d_lock); single_release(inode, file); ret = -EINVAL; } } return ret; } static int rpc_info_release(struct inode *inode, struct file *file) { struct seq_file *m = file->private_data; struct rpc_clnt *clnt = (struct rpc_clnt *)m->private; if (clnt) rpc_release_client(clnt); return single_release(inode, file); } static const struct file_operations rpc_info_operations = { .owner = THIS_MODULE, .open = rpc_info_open, .read = seq_read, .llseek = seq_lseek, .release = rpc_info_release, }; /* * Description of fs contents. */ struct rpc_filelist { const char *name; const struct file_operations *i_fop; umode_t mode; }; static struct inode * rpc_get_inode(struct super_block *sb, umode_t mode) { struct inode *inode = new_inode(sb); if (!inode) return NULL; inode->i_ino = get_next_ino(); inode->i_mode = mode; inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); switch (mode & S_IFMT) { case S_IFDIR: inode->i_fop = &simple_dir_operations; inode->i_op = &simple_dir_inode_operations; inc_nlink(inode); default: break; } return inode; } static int __rpc_create_common(struct inode *dir, struct dentry *dentry, umode_t mode, const struct file_operations *i_fop, void *private) { struct inode *inode; d_drop(dentry); inode = rpc_get_inode(dir->i_sb, mode); if (!inode) goto out_err; inode->i_ino = iunique(dir->i_sb, 100); if (i_fop) inode->i_fop = i_fop; if (private) rpc_inode_setowner(inode, private); d_add(dentry, inode); return 0; out_err: printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %pd\n", __FILE__, __func__, dentry); dput(dentry); return -ENOMEM; } static int __rpc_create(struct inode *dir, struct dentry *dentry, umode_t mode, const struct file_operations *i_fop, void *private) { int err; err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private); if (err) return err; fsnotify_create(dir, dentry); return 0; } static int __rpc_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode, const struct file_operations *i_fop, void *private) { int err; err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private); if (err) return err; inc_nlink(dir); fsnotify_mkdir(dir, dentry); return 0; } static void init_pipe(struct rpc_pipe *pipe) { pipe->nreaders = 0; pipe->nwriters = 0; INIT_LIST_HEAD(&pipe->in_upcall); INIT_LIST_HEAD(&pipe->in_downcall); INIT_LIST_HEAD(&pipe->pipe); pipe->pipelen = 0; INIT_DELAYED_WORK(&pipe->queue_timeout, rpc_timeout_upcall_queue); pipe->ops = NULL; spin_lock_init(&pipe->lock); pipe->dentry = NULL; } void rpc_destroy_pipe_data(struct rpc_pipe *pipe) { kfree(pipe); } EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data); struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags) { struct rpc_pipe *pipe; pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL); if (!pipe) return ERR_PTR(-ENOMEM); init_pipe(pipe); pipe->ops = ops; pipe->flags = flags; return pipe; } EXPORT_SYMBOL_GPL(rpc_mkpipe_data); static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry, umode_t mode, const struct file_operations *i_fop, void *private, struct rpc_pipe *pipe) { struct rpc_inode *rpci; int err; err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private); if (err) return err; rpci = RPC_I(d_inode(dentry)); rpci->private = private; rpci->pipe = pipe; fsnotify_create(dir, dentry); return 0; } static int __rpc_rmdir(struct inode *dir, struct dentry *dentry) { int ret; dget(dentry); ret = simple_rmdir(dir, dentry); if (!ret) fsnotify_rmdir(dir, dentry); d_delete(dentry); dput(dentry); return ret; } static int __rpc_unlink(struct inode *dir, struct dentry *dentry) { int ret; dget(dentry); ret = simple_unlink(dir, dentry); if (!ret) fsnotify_unlink(dir, dentry); d_delete(dentry); dput(dentry); return ret; } static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry) { struct inode *inode = d_inode(dentry); rpc_close_pipes(inode); return __rpc_unlink(dir, dentry); } static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent, const char *name) { struct qstr q = QSTR_INIT(name, strlen(name)); struct dentry *dentry = d_hash_and_lookup(parent, &q); if (!dentry) { dentry = d_alloc(parent, &q); if (!dentry) return ERR_PTR(-ENOMEM); } if (d_really_is_negative(dentry)) return dentry; dput(dentry); return ERR_PTR(-EEXIST); } /* * FIXME: This probably has races. */ static void __rpc_depopulate(struct dentry *parent, const struct rpc_filelist *files, int start, int eof) { struct inode *dir = d_inode(parent); struct dentry *dentry; struct qstr name; int i; for (i = start; i < eof; i++) { name.name = files[i].name; name.len = strlen(files[i].name); dentry = d_hash_and_lookup(parent, &name); if (dentry == NULL) continue; if (d_really_is_negative(dentry)) goto next; switch (d_inode(dentry)->i_mode & S_IFMT) { default: BUG(); case S_IFREG: __rpc_unlink(dir, dentry); break; case S_IFDIR: __rpc_rmdir(dir, dentry); } next: dput(dentry); } } static void rpc_depopulate(struct dentry *parent, const struct rpc_filelist *files, int start, int eof) { struct inode *dir = d_inode(parent); inode_lock_nested(dir, I_MUTEX_CHILD); __rpc_depopulate(parent, files, start, eof); inode_unlock(dir); } static int rpc_populate(struct dentry *parent, const struct rpc_filelist *files, int start, int eof, void *private) { struct inode *dir = d_inode(parent); struct dentry *dentry; int i, err; inode_lock(dir); for (i = start; i < eof; i++) { dentry = __rpc_lookup_create_exclusive(parent, files[i].name); err = PTR_ERR(dentry); if (IS_ERR(dentry)) goto out_bad; switch (files[i].mode & S_IFMT) { default: BUG(); case S_IFREG: err = __rpc_create(dir, dentry, files[i].mode, files[i].i_fop, private); break; case S_IFDIR: err = __rpc_mkdir(dir, dentry, files[i].mode, NULL, private); } if (err != 0) goto out_bad; } inode_unlock(dir); return 0; out_bad: __rpc_depopulate(parent, files, start, eof); inode_unlock(dir); printk(KERN_WARNING "%s: %s failed to populate directory %pd\n", __FILE__, __func__, parent); return err; } static struct dentry *rpc_mkdir_populate(struct dentry *parent, const char *name, umode_t mode, void *private, int (*populate)(struct dentry *, void *), void *args_populate) { struct dentry *dentry; struct inode *dir = d_inode(parent); int error; inode_lock_nested(dir, I_MUTEX_PARENT); dentry = __rpc_lookup_create_exclusive(parent, name); if (IS_ERR(dentry)) goto out; error = __rpc_mkdir(dir, dentry, mode, NULL, private); if (error != 0) goto out_err; if (populate != NULL) { error = populate(dentry, args_populate); if (error) goto err_rmdir; } out: inode_unlock(dir); return dentry; err_rmdir: __rpc_rmdir(dir, dentry); out_err: dentry = ERR_PTR(error); goto out; } static int rpc_rmdir_depopulate(struct dentry *dentry, void (*depopulate)(struct dentry *)) { struct dentry *parent; struct inode *dir; int error; parent = dget_parent(dentry); dir = d_inode(parent); inode_lock_nested(dir, I_MUTEX_PARENT); if (depopulate != NULL) depopulate(dentry); error = __rpc_rmdir(dir, dentry); inode_unlock(dir); dput(parent); return error; } /** * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication * @parent: dentry of directory to create new "pipe" in * @name: name of pipe * @private: private data to associate with the pipe, for the caller's use * @pipe: &rpc_pipe containing input parameters * * Data is made available for userspace to read by calls to * rpc_queue_upcall(). The actual reads will result in calls to * @ops->upcall, which will be called with the file pointer, * message, and userspace buffer to copy to. * * Writes can come at any time, and do not necessarily have to be * responses to upcalls. They will result in calls to @msg->downcall. * * The @private argument passed here will be available to all these methods * from the file pointer, via RPC_I(file_inode(file))->private. */ struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name, void *private, struct rpc_pipe *pipe) { struct dentry *dentry; struct inode *dir = d_inode(parent); umode_t umode = S_IFIFO | 0600; int err; if (pipe->ops->upcall == NULL) umode &= ~0444; if (pipe->ops->downcall == NULL) umode &= ~0222; inode_lock_nested(dir, I_MUTEX_PARENT); dentry = __rpc_lookup_create_exclusive(parent, name); if (IS_ERR(dentry)) goto out; err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops, private, pipe); if (err) goto out_err; out: inode_unlock(dir); return dentry; out_err: dentry = ERR_PTR(err); printk(KERN_WARNING "%s: %s() failed to create pipe %pd/%s (errno = %d)\n", __FILE__, __func__, parent, name, err); goto out; } EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry); /** * rpc_unlink - remove a pipe * @dentry: dentry for the pipe, as returned from rpc_mkpipe * * After this call, lookups will no longer find the pipe, and any * attempts to read or write using preexisting opens of the pipe will * return -EPIPE. */ int rpc_unlink(struct dentry *dentry) { struct dentry *parent; struct inode *dir; int error = 0; parent = dget_parent(dentry); dir = d_inode(parent); inode_lock_nested(dir, I_MUTEX_PARENT); error = __rpc_rmpipe(dir, dentry); inode_unlock(dir); dput(parent); return error; } EXPORT_SYMBOL_GPL(rpc_unlink); /** * rpc_init_pipe_dir_head - initialise a struct rpc_pipe_dir_head * @pdh: pointer to struct rpc_pipe_dir_head */ void rpc_init_pipe_dir_head(struct rpc_pipe_dir_head *pdh) { INIT_LIST_HEAD(&pdh->pdh_entries); pdh->pdh_dentry = NULL; } EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_head); /** * rpc_init_pipe_dir_object - initialise a struct rpc_pipe_dir_object * @pdo: pointer to struct rpc_pipe_dir_object * @pdo_ops: pointer to const struct rpc_pipe_dir_object_ops * @pdo_data: pointer to caller-defined data */ void rpc_init_pipe_dir_object(struct rpc_pipe_dir_object *pdo, const struct rpc_pipe_dir_object_ops *pdo_ops, void *pdo_data) { INIT_LIST_HEAD(&pdo->pdo_head); pdo->pdo_ops = pdo_ops; pdo->pdo_data = pdo_data; } EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_object); static int rpc_add_pipe_dir_object_locked(struct net *net, struct rpc_pipe_dir_head *pdh, struct rpc_pipe_dir_object *pdo) { int ret = 0; if (pdh->pdh_dentry) ret = pdo->pdo_ops->create(pdh->pdh_dentry, pdo); if (ret == 0) list_add_tail(&pdo->pdo_head, &pdh->pdh_entries); return ret; } static void rpc_remove_pipe_dir_object_locked(struct net *net, struct rpc_pipe_dir_head *pdh, struct rpc_pipe_dir_object *pdo) { if (pdh->pdh_dentry) pdo->pdo_ops->destroy(pdh->pdh_dentry, pdo); list_del_init(&pdo->pdo_head); } /** * rpc_add_pipe_dir_object - associate a rpc_pipe_dir_object to a directory * @net: pointer to struct net * @pdh: pointer to struct rpc_pipe_dir_head * @pdo: pointer to struct rpc_pipe_dir_object * */ int rpc_add_pipe_dir_object(struct net *net, struct rpc_pipe_dir_head *pdh, struct rpc_pipe_dir_object *pdo) { int ret = 0; if (list_empty(&pdo->pdo_head)) { struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); mutex_lock(&sn->pipefs_sb_lock); ret = rpc_add_pipe_dir_object_locked(net, pdh, pdo); mutex_unlock(&sn->pipefs_sb_lock); } return ret; } EXPORT_SYMBOL_GPL(rpc_add_pipe_dir_object); /** * rpc_remove_pipe_dir_object - remove a rpc_pipe_dir_object from a directory * @net: pointer to struct net * @pdh: pointer to struct rpc_pipe_dir_head * @pdo: pointer to struct rpc_pipe_dir_object * */ void rpc_remove_pipe_dir_object(struct net *net, struct rpc_pipe_dir_head *pdh, struct rpc_pipe_dir_object *pdo) { if (!list_empty(&pdo->pdo_head)) { struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); mutex_lock(&sn->pipefs_sb_lock); rpc_remove_pipe_dir_object_locked(net, pdh, pdo); mutex_unlock(&sn->pipefs_sb_lock); } } EXPORT_SYMBOL_GPL(rpc_remove_pipe_dir_object); /** * rpc_find_or_alloc_pipe_dir_object * @net: pointer to struct net * @pdh: pointer to struct rpc_pipe_dir_head * @match: match struct rpc_pipe_dir_object to data * @alloc: allocate a new struct rpc_pipe_dir_object * @data: user defined data for match() and alloc() * */ struct rpc_pipe_dir_object * rpc_find_or_alloc_pipe_dir_object(struct net *net, struct rpc_pipe_dir_head *pdh, int (*match)(struct rpc_pipe_dir_object *, void *), struct rpc_pipe_dir_object *(*alloc)(void *), void *data) { struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); struct rpc_pipe_dir_object *pdo; mutex_lock(&sn->pipefs_sb_lock); list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head) { if (!match(pdo, data)) continue; goto out; } pdo = alloc(data); if (!pdo) goto out; rpc_add_pipe_dir_object_locked(net, pdh, pdo); out: mutex_unlock(&sn->pipefs_sb_lock); return pdo; } EXPORT_SYMBOL_GPL(rpc_find_or_alloc_pipe_dir_object); static void rpc_create_pipe_dir_objects(struct rpc_pipe_dir_head *pdh) { struct rpc_pipe_dir_object *pdo; struct dentry *dir = pdh->pdh_dentry; list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head) pdo->pdo_ops->create(dir, pdo); } static void rpc_destroy_pipe_dir_objects(struct rpc_pipe_dir_head *pdh) { struct rpc_pipe_dir_object *pdo; struct dentry *dir = pdh->pdh_dentry; list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head) pdo->pdo_ops->destroy(dir, pdo); } enum { RPCAUTH_info, RPCAUTH_EOF }; static const struct rpc_filelist authfiles[] = { [RPCAUTH_info] = { .name = "info", .i_fop = &rpc_info_operations, .mode = S_IFREG | 0400, }, }; static int rpc_clntdir_populate(struct dentry *dentry, void *private) { return rpc_populate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF, private); } static void rpc_clntdir_depopulate(struct dentry *dentry) { rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF); } /** * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs * @dentry: the parent of new directory * @name: the name of new directory * @rpc_client: rpc client to associate with this directory * * This creates a directory at the given @path associated with * @rpc_clnt, which will contain a file named "info" with some basic * information about the client, together with any "pipes" that may * later be created using rpc_mkpipe(). */ struct dentry *rpc_create_client_dir(struct dentry *dentry, const char *name, struct rpc_clnt *rpc_client) { struct dentry *ret; ret = rpc_mkdir_populate(dentry, name, 0555, NULL, rpc_clntdir_populate, rpc_client); if (!IS_ERR(ret)) { rpc_client->cl_pipedir_objects.pdh_dentry = ret; rpc_create_pipe_dir_objects(&rpc_client->cl_pipedir_objects); } return ret; } /** * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir() * @rpc_client: rpc_client for the pipe */ int rpc_remove_client_dir(struct rpc_clnt *rpc_client) { struct dentry *dentry = rpc_client->cl_pipedir_objects.pdh_dentry; if (dentry == NULL) return 0; rpc_destroy_pipe_dir_objects(&rpc_client->cl_pipedir_objects); rpc_client->cl_pipedir_objects.pdh_dentry = NULL; return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate); } static const struct rpc_filelist cache_pipefs_files[3] = { [0] = { .name = "channel", .i_fop = &cache_file_operations_pipefs, .mode = S_IFREG | 0600, }, [1] = { .name = "content", .i_fop = &content_file_operations_pipefs, .mode = S_IFREG | 0400, }, [2] = { .name = "flush", .i_fop = &cache_flush_operations_pipefs, .mode = S_IFREG | 0600, }, }; static int rpc_cachedir_populate(struct dentry *dentry, void *private) { return rpc_populate(dentry, cache_pipefs_files, 0, 3, private); } static void rpc_cachedir_depopulate(struct dentry *dentry) { rpc_depopulate(dentry, cache_pipefs_files, 0, 3); } struct dentry *rpc_create_cache_dir(struct dentry *parent, const char *name, umode_t umode, struct cache_detail *cd) { return rpc_mkdir_populate(parent, name, umode, NULL, rpc_cachedir_populate, cd); } void rpc_remove_cache_dir(struct dentry *dentry) { rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate); } /* * populate the filesystem */ static const struct super_operations s_ops = { .alloc_inode = rpc_alloc_inode, .free_inode = rpc_free_inode, .statfs = simple_statfs, }; #define RPCAUTH_GSSMAGIC 0x67596969 /* * We have a single directory with 1 node in it. */ enum { RPCAUTH_lockd, RPCAUTH_mount, RPCAUTH_nfs, RPCAUTH_portmap, RPCAUTH_statd, RPCAUTH_nfsd4_cb, RPCAUTH_cache, RPCAUTH_nfsd, RPCAUTH_gssd, RPCAUTH_RootEOF }; static const struct rpc_filelist files[] = { [RPCAUTH_lockd] = { .name = "lockd", .mode = S_IFDIR | 0555, }, [RPCAUTH_mount] = { .name = "mount", .mode = S_IFDIR | 0555, }, [RPCAUTH_nfs] = { .name = "nfs", .mode = S_IFDIR | 0555, }, [RPCAUTH_portmap] = { .name = "portmap", .mode = S_IFDIR | 0555, }, [RPCAUTH_statd] = { .name = "statd", .mode = S_IFDIR | 0555, }, [RPCAUTH_nfsd4_cb] = { .name = "nfsd4_cb", .mode = S_IFDIR | 0555, }, [RPCAUTH_cache] = { .name = "cache", .mode = S_IFDIR | 0555, }, [RPCAUTH_nfsd] = { .name = "nfsd", .mode = S_IFDIR | 0555, }, [RPCAUTH_gssd] = { .name = "gssd", .mode = S_IFDIR | 0555, }, }; /* * This call can be used only in RPC pipefs mount notification hooks. */ struct dentry *rpc_d_lookup_sb(const struct super_block *sb, const unsigned char *dir_name) { struct qstr dir = QSTR_INIT(dir_name, strlen(dir_name)); return d_hash_and_lookup(sb->s_root, &dir); } EXPORT_SYMBOL_GPL(rpc_d_lookup_sb); int rpc_pipefs_init_net(struct net *net) { struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); sn->gssd_dummy = rpc_mkpipe_data(&gssd_dummy_pipe_ops, 0); if (IS_ERR(sn->gssd_dummy)) return PTR_ERR(sn->gssd_dummy); mutex_init(&sn->pipefs_sb_lock); sn->pipe_version = -1; return 0; } void rpc_pipefs_exit_net(struct net *net) { struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); rpc_destroy_pipe_data(sn->gssd_dummy); } /* * This call will be used for per network namespace operations calls. * Note: Function will be returned with pipefs_sb_lock taken if superblock was * found. This lock have to be released by rpc_put_sb_net() when all operations * will be completed. */ struct super_block *rpc_get_sb_net(const struct net *net) { struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); mutex_lock(&sn->pipefs_sb_lock); if (sn->pipefs_sb) return sn->pipefs_sb; mutex_unlock(&sn->pipefs_sb_lock); return NULL; } EXPORT_SYMBOL_GPL(rpc_get_sb_net); void rpc_put_sb_net(const struct net *net) { struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); WARN_ON(sn->pipefs_sb == NULL); mutex_unlock(&sn->pipefs_sb_lock); } EXPORT_SYMBOL_GPL(rpc_put_sb_net); static const struct rpc_filelist gssd_dummy_clnt_dir[] = { [0] = { .name = "clntXX", .mode = S_IFDIR | 0555, }, }; static ssize_t dummy_downcall(struct file *filp, const char __user *src, size_t len) { return -EINVAL; } static const struct rpc_pipe_ops gssd_dummy_pipe_ops = { .upcall = rpc_pipe_generic_upcall, .downcall = dummy_downcall, }; /* * Here we present a bogus "info" file to keep rpc.gssd happy. We don't expect * that it will ever use this info to handle an upcall, but rpc.gssd expects * that this file will be there and have a certain format. */ static int rpc_dummy_info_show(struct seq_file *m, void *v) { seq_printf(m, "RPC server: %s\n", utsname()->nodename); seq_printf(m, "service: foo (1) version 0\n"); seq_printf(m, "address: 127.0.0.1\n"); seq_printf(m, "protocol: tcp\n"); seq_printf(m, "port: 0\n"); return 0; } DEFINE_SHOW_ATTRIBUTE(rpc_dummy_info); static const struct rpc_filelist gssd_dummy_info_file[] = { [0] = { .name = "info", .i_fop = &rpc_dummy_info_fops, .mode = S_IFREG | 0400, }, }; /** * rpc_gssd_dummy_populate - create a dummy gssd pipe * @root: root of the rpc_pipefs filesystem * @pipe_data: pipe data created when netns is initialized * * Create a dummy set of directories and a pipe that gssd can hold open to * indicate that it is up and running. */ static struct dentry * rpc_gssd_dummy_populate(struct dentry *root, struct rpc_pipe *pipe_data) { int ret = 0; struct dentry *gssd_dentry; struct dentry *clnt_dentry = NULL; struct dentry *pipe_dentry = NULL; struct qstr q = QSTR_INIT(files[RPCAUTH_gssd].name, strlen(files[RPCAUTH_gssd].name)); /* We should never get this far if "gssd" doesn't exist */ gssd_dentry = d_hash_and_lookup(root, &q); if (!gssd_dentry) return ERR_PTR(-ENOENT); ret = rpc_populate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1, NULL); if (ret) { pipe_dentry = ERR_PTR(ret); goto out; } q.name = gssd_dummy_clnt_dir[0].name; q.len = strlen(gssd_dummy_clnt_dir[0].name); clnt_dentry = d_hash_and_lookup(gssd_dentry, &q); if (!clnt_dentry) { pipe_dentry = ERR_PTR(-ENOENT); goto out; } ret = rpc_populate(clnt_dentry, gssd_dummy_info_file, 0, 1, NULL); if (ret) { __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1); pipe_dentry = ERR_PTR(ret); goto out; } pipe_dentry = rpc_mkpipe_dentry(clnt_dentry, "gssd", NULL, pipe_data); if (IS_ERR(pipe_dentry)) { __rpc_depopulate(clnt_dentry, gssd_dummy_info_file, 0, 1); __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1); } out: dput(clnt_dentry); dput(gssd_dentry); return pipe_dentry; } static void rpc_gssd_dummy_depopulate(struct dentry *pipe_dentry) { struct dentry *clnt_dir = pipe_dentry->d_parent; struct dentry *gssd_dir = clnt_dir->d_parent; dget(pipe_dentry); __rpc_rmpipe(d_inode(clnt_dir), pipe_dentry); __rpc_depopulate(clnt_dir, gssd_dummy_info_file, 0, 1); __rpc_depopulate(gssd_dir, gssd_dummy_clnt_dir, 0, 1); dput(pipe_dentry); } static int rpc_fill_super(struct super_block *sb, struct fs_context *fc) { struct inode *inode; struct dentry *root, *gssd_dentry; struct net *net = sb->s_fs_info; struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); int err; sb->s_blocksize = PAGE_SIZE; sb->s_blocksize_bits = PAGE_SHIFT; sb->s_magic = RPCAUTH_GSSMAGIC; sb->s_op = &s_ops; sb->s_d_op = &simple_dentry_operations; sb->s_time_gran = 1; inode = rpc_get_inode(sb, S_IFDIR | 0555); sb->s_root = root = d_make_root(inode); if (!root) return -ENOMEM; if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL)) return -ENOMEM; gssd_dentry = rpc_gssd_dummy_populate(root, sn->gssd_dummy); if (IS_ERR(gssd_dentry)) { __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF); return PTR_ERR(gssd_dentry); } dprintk("RPC: sending pipefs MOUNT notification for net %x%s\n", net->ns.inum, NET_NAME(net)); mutex_lock(&sn->pipefs_sb_lock); sn->pipefs_sb = sb; err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list, RPC_PIPEFS_MOUNT, sb); if (err) goto err_depopulate; mutex_unlock(&sn->pipefs_sb_lock); return 0; err_depopulate: rpc_gssd_dummy_depopulate(gssd_dentry); blocking_notifier_call_chain(&rpc_pipefs_notifier_list, RPC_PIPEFS_UMOUNT, sb); sn->pipefs_sb = NULL; __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF); mutex_unlock(&sn->pipefs_sb_lock); return err; } bool gssd_running(struct net *net) { struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); struct rpc_pipe *pipe = sn->gssd_dummy; return pipe->nreaders || pipe->nwriters; } EXPORT_SYMBOL_GPL(gssd_running); static int rpc_fs_get_tree(struct fs_context *fc) { return get_tree_keyed(fc, rpc_fill_super, get_net(fc->net_ns)); } static void rpc_fs_free_fc(struct fs_context *fc) { if (fc->s_fs_info) put_net(fc->s_fs_info); } static const struct fs_context_operations rpc_fs_context_ops = { .free = rpc_fs_free_fc, .get_tree = rpc_fs_get_tree, }; static int rpc_init_fs_context(struct fs_context *fc) { put_user_ns(fc->user_ns); fc->user_ns = get_user_ns(fc->net_ns->user_ns); fc->ops = &rpc_fs_context_ops; return 0; } static void rpc_kill_sb(struct super_block *sb) { struct net *net = sb->s_fs_info; struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); mutex_lock(&sn->pipefs_sb_lock); if (sn->pipefs_sb != sb) { mutex_unlock(&sn->pipefs_sb_lock); goto out; } sn->pipefs_sb = NULL; dprintk("RPC: sending pipefs UMOUNT notification for net %x%s\n", net->ns.inum, NET_NAME(net)); blocking_notifier_call_chain(&rpc_pipefs_notifier_list, RPC_PIPEFS_UMOUNT, sb); mutex_unlock(&sn->pipefs_sb_lock); out: kill_litter_super(sb); put_net(net); } static struct file_system_type rpc_pipe_fs_type = { .owner = THIS_MODULE, .name = "rpc_pipefs", .init_fs_context = rpc_init_fs_context, .kill_sb = rpc_kill_sb, }; MODULE_ALIAS_FS("rpc_pipefs"); MODULE_ALIAS("rpc_pipefs"); static void init_once(void *foo) { struct rpc_inode *rpci = (struct rpc_inode *) foo; inode_init_once(&rpci->vfs_inode); rpci->private = NULL; rpci->pipe = NULL; init_waitqueue_head(&rpci->waitq); } int register_rpc_pipefs(void) { int err; rpc_inode_cachep = kmem_cache_create("rpc_inode_cache", sizeof(struct rpc_inode), 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| SLAB_MEM_SPREAD|SLAB_ACCOUNT), init_once); if (!rpc_inode_cachep) return -ENOMEM; err = rpc_clients_notifier_register(); if (err) goto err_notifier; err = register_filesystem(&rpc_pipe_fs_type); if (err) goto err_register; return 0; err_register: rpc_clients_notifier_unregister(); err_notifier: kmem_cache_destroy(rpc_inode_cachep); return err; } void unregister_rpc_pipefs(void) { rpc_clients_notifier_unregister(); kmem_cache_destroy(rpc_inode_cachep); unregister_filesystem(&rpc_pipe_fs_type); }