/* * 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 <trond.myklebust@fys.uio.no> * */ #include <linux/module.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/pagemap.h> #include <linux/mount.h> #include <linux/namei.h> #include <linux/dnotify.h> #include <linux/kernel.h> #include <asm/ioctls.h> #include <linux/fs.h> #include <linux/poll.h> #include <linux/wait.h> #include <linux/seq_file.h> #include <linux/sunrpc/clnt.h> #include <linux/workqueue.h> #include <linux/sunrpc/rpc_pipe_fs.h> static struct vfsmount *rpc_mount __read_mostly; static int rpc_mount_count; static struct file_system_type rpc_pipe_fs_type; static kmem_cache_t *rpc_inode_cachep __read_mostly; #define RPC_UPCALL_TIMEOUT (30*HZ) static void rpc_purge_list(struct rpc_inode *rpci, 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(&msg->list); msg->errno = err; destroy_msg(msg); } while (!list_empty(head)); wake_up(&rpci->waitq); } static void rpc_timeout_upcall_queue(void *data) { LIST_HEAD(free_list); struct rpc_inode *rpci = (struct rpc_inode *)data; struct inode *inode = &rpci->vfs_inode; void (*destroy_msg)(struct rpc_pipe_msg *); spin_lock(&inode->i_lock); if (rpci->ops == NULL) { spin_unlock(&inode->i_lock); return; } destroy_msg = rpci->ops->destroy_msg; if (rpci->nreaders == 0) { list_splice_init(&rpci->pipe, &free_list); rpci->pipelen = 0; } spin_unlock(&inode->i_lock); rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT); } int rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg) { struct rpc_inode *rpci = RPC_I(inode); int res = -EPIPE; spin_lock(&inode->i_lock); if (rpci->ops == NULL) goto out; if (rpci->nreaders) { list_add_tail(&msg->list, &rpci->pipe); rpci->pipelen += msg->len; res = 0; } else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) { if (list_empty(&rpci->pipe)) queue_delayed_work(rpciod_workqueue, &rpci->queue_timeout, RPC_UPCALL_TIMEOUT); list_add_tail(&msg->list, &rpci->pipe); rpci->pipelen += msg->len; res = 0; } out: spin_unlock(&inode->i_lock); wake_up(&rpci->waitq); return res; } 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_inode *rpci = RPC_I(inode); struct rpc_pipe_ops *ops; mutex_lock(&inode->i_mutex); ops = rpci->ops; if (ops != NULL) { LIST_HEAD(free_list); spin_lock(&inode->i_lock); rpci->nreaders = 0; list_splice_init(&rpci->in_upcall, &free_list); list_splice_init(&rpci->pipe, &free_list); rpci->pipelen = 0; rpci->ops = NULL; spin_unlock(&inode->i_lock); rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE); rpci->nwriters = 0; if (ops->release_pipe) ops->release_pipe(inode); cancel_delayed_work(&rpci->queue_timeout); flush_workqueue(rpciod_workqueue); } rpc_inode_setowner(inode, NULL); mutex_unlock(&inode->i_mutex); } static struct inode * rpc_alloc_inode(struct super_block *sb) { struct rpc_inode *rpci; rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, SLAB_KERNEL); if (!rpci) return NULL; return &rpci->vfs_inode; } static void rpc_destroy_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_inode *rpci = RPC_I(inode); int res = -ENXIO; mutex_lock(&inode->i_mutex); if (rpci->ops != NULL) { if (filp->f_mode & FMODE_READ) rpci->nreaders ++; if (filp->f_mode & FMODE_WRITE) rpci->nwriters ++; res = 0; } mutex_unlock(&inode->i_mutex); return res; } static int rpc_pipe_release(struct inode *inode, struct file *filp) { struct rpc_inode *rpci = RPC_I(inode); struct rpc_pipe_msg *msg; mutex_lock(&inode->i_mutex); if (rpci->ops == NULL) goto out; msg = (struct rpc_pipe_msg *)filp->private_data; if (msg != NULL) { spin_lock(&inode->i_lock); msg->errno = -EAGAIN; list_del(&msg->list); spin_unlock(&inode->i_lock); rpci->ops->destroy_msg(msg); } if (filp->f_mode & FMODE_WRITE) rpci->nwriters --; if (filp->f_mode & FMODE_READ) { rpci->nreaders --; if (rpci->nreaders == 0) { LIST_HEAD(free_list); spin_lock(&inode->i_lock); list_splice_init(&rpci->pipe, &free_list); rpci->pipelen = 0; spin_unlock(&inode->i_lock); rpc_purge_list(rpci, &free_list, rpci->ops->destroy_msg, -EAGAIN); } } if (rpci->ops->release_pipe) rpci->ops->release_pipe(inode); out: mutex_unlock(&inode->i_mutex); return 0; } static ssize_t rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset) { struct inode *inode = filp->f_dentry->d_inode; struct rpc_inode *rpci = RPC_I(inode); struct rpc_pipe_msg *msg; int res = 0; mutex_lock(&inode->i_mutex); if (rpci->ops == NULL) { res = -EPIPE; goto out_unlock; } msg = filp->private_data; if (msg == NULL) { spin_lock(&inode->i_lock); if (!list_empty(&rpci->pipe)) { msg = list_entry(rpci->pipe.next, struct rpc_pipe_msg, list); list_move(&msg->list, &rpci->in_upcall); rpci->pipelen -= msg->len; filp->private_data = msg; msg->copied = 0; } spin_unlock(&inode->i_lock); if (msg == NULL) goto out_unlock; } /* NOTE: it is up to the callback to update msg->copied */ res = rpci->ops->upcall(filp, msg, buf, len); if (res < 0 || msg->len == msg->copied) { filp->private_data = NULL; spin_lock(&inode->i_lock); list_del(&msg->list); spin_unlock(&inode->i_lock); rpci->ops->destroy_msg(msg); } out_unlock: mutex_unlock(&inode->i_mutex); return res; } static ssize_t rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset) { struct inode *inode = filp->f_dentry->d_inode; struct rpc_inode *rpci = RPC_I(inode); int res; mutex_lock(&inode->i_mutex); res = -EPIPE; if (rpci->ops != NULL) res = rpci->ops->downcall(filp, buf, len); mutex_unlock(&inode->i_mutex); return res; } static unsigned int rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait) { struct rpc_inode *rpci; unsigned int mask = 0; rpci = RPC_I(filp->f_dentry->d_inode); poll_wait(filp, &rpci->waitq, wait); mask = POLLOUT | POLLWRNORM; if (rpci->ops == NULL) mask |= POLLERR | POLLHUP; if (!list_empty(&rpci->pipe)) mask |= POLLIN | POLLRDNORM; return mask; } static int rpc_pipe_ioctl(struct inode *ino, struct file *filp, unsigned int cmd, unsigned long arg) { struct rpc_inode *rpci = RPC_I(filp->f_dentry->d_inode); int len; switch (cmd) { case FIONREAD: if (rpci->ops == NULL) return -EPIPE; len = rpci->pipelen; if (filp->private_data) { struct rpc_pipe_msg *msg; msg = (struct rpc_pipe_msg *)filp->private_data; len += msg->len - msg->copied; } return put_user(len, (int __user *)arg); default: return -EINVAL; } } static struct file_operations rpc_pipe_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .read = rpc_pipe_read, .write = rpc_pipe_write, .poll = rpc_pipe_poll, .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; seq_printf(m, "RPC server: %s\n", clnt->cl_server); seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname, 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)); return 0; } static int rpc_info_open(struct inode *inode, struct file *file) { struct rpc_clnt *clnt; int ret = single_open(file, rpc_show_info, NULL); if (!ret) { struct seq_file *m = file->private_data; mutex_lock(&inode->i_mutex); clnt = RPC_I(inode)->private; if (clnt) { atomic_inc(&clnt->cl_users); m->private = clnt; } else { single_release(inode, file); ret = -EINVAL; } mutex_unlock(&inode->i_mutex); } 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 struct file_operations rpc_info_operations = { .owner = THIS_MODULE, .open = rpc_info_open, .read = seq_read, .llseek = seq_lseek, .release = rpc_info_release, }; /* * We have a single directory with 1 node in it. */ enum { RPCAUTH_Root = 1, RPCAUTH_lockd, RPCAUTH_mount, RPCAUTH_nfs, RPCAUTH_portmap, RPCAUTH_statd, RPCAUTH_RootEOF }; /* * Description of fs contents. */ struct rpc_filelist { char *name; const struct file_operations *i_fop; int mode; }; static struct rpc_filelist files[] = { [RPCAUTH_lockd] = { .name = "lockd", .mode = S_IFDIR | S_IRUGO | S_IXUGO, }, [RPCAUTH_mount] = { .name = "mount", .mode = S_IFDIR | S_IRUGO | S_IXUGO, }, [RPCAUTH_nfs] = { .name = "nfs", .mode = S_IFDIR | S_IRUGO | S_IXUGO, }, [RPCAUTH_portmap] = { .name = "portmap", .mode = S_IFDIR | S_IRUGO | S_IXUGO, }, [RPCAUTH_statd] = { .name = "statd", .mode = S_IFDIR | S_IRUGO | S_IXUGO, }, }; enum { RPCAUTH_info = 2, RPCAUTH_EOF }; static struct rpc_filelist authfiles[] = { [RPCAUTH_info] = { .name = "info", .i_fop = &rpc_info_operations, .mode = S_IFREG | S_IRUSR, }, }; struct vfsmount *rpc_get_mount(void) { int err; err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count); if (err != 0) return ERR_PTR(err); return rpc_mount; } void rpc_put_mount(void) { simple_release_fs(&rpc_mount, &rpc_mount_count); } static int rpc_lookup_parent(char *path, struct nameidata *nd) { if (path[0] == '\0') return -ENOENT; nd->mnt = rpc_get_mount(); if (IS_ERR(nd->mnt)) { printk(KERN_WARNING "%s: %s failed to mount " "pseudofilesystem \n", __FILE__, __FUNCTION__); return PTR_ERR(nd->mnt); } mntget(nd->mnt); nd->dentry = dget(rpc_mount->mnt_root); nd->last_type = LAST_ROOT; nd->flags = LOOKUP_PARENT; nd->depth = 0; if (path_walk(path, nd)) { printk(KERN_WARNING "%s: %s failed to find path %s\n", __FILE__, __FUNCTION__, path); rpc_put_mount(); return -ENOENT; } return 0; } static void rpc_release_path(struct nameidata *nd) { path_release(nd); rpc_put_mount(); } static struct inode * rpc_get_inode(struct super_block *sb, int mode) { struct inode *inode = new_inode(sb); if (!inode) return NULL; inode->i_mode = mode; inode->i_uid = inode->i_gid = 0; inode->i_blocks = 0; inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 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; } /* * FIXME: This probably has races. */ static void rpc_depopulate(struct dentry *parent) { struct inode *dir = parent->d_inode; struct list_head *pos, *next; struct dentry *dentry, *dvec[10]; int n = 0; mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD); repeat: spin_lock(&dcache_lock); list_for_each_safe(pos, next, &parent->d_subdirs) { dentry = list_entry(pos, struct dentry, d_u.d_child); spin_lock(&dentry->d_lock); if (!d_unhashed(dentry)) { dget_locked(dentry); __d_drop(dentry); spin_unlock(&dentry->d_lock); dvec[n++] = dentry; if (n == ARRAY_SIZE(dvec)) break; } else spin_unlock(&dentry->d_lock); } spin_unlock(&dcache_lock); if (n) { do { dentry = dvec[--n]; if (dentry->d_inode) { rpc_close_pipes(dentry->d_inode); simple_unlink(dir, dentry); } inode_dir_notify(dir, DN_DELETE); dput(dentry); } while (n); goto repeat; } mutex_unlock(&dir->i_mutex); } static int rpc_populate(struct dentry *parent, struct rpc_filelist *files, int start, int eof) { struct inode *inode, *dir = parent->d_inode; void *private = RPC_I(dir)->private; struct dentry *dentry; int mode, i; mutex_lock(&dir->i_mutex); for (i = start; i < eof; i++) { dentry = d_alloc_name(parent, files[i].name); if (!dentry) goto out_bad; mode = files[i].mode; inode = rpc_get_inode(dir->i_sb, mode); if (!inode) { dput(dentry); goto out_bad; } inode->i_ino = i; if (files[i].i_fop) inode->i_fop = files[i].i_fop; if (private) rpc_inode_setowner(inode, private); if (S_ISDIR(mode)) inc_nlink(dir); d_add(dentry, inode); } mutex_unlock(&dir->i_mutex); return 0; out_bad: mutex_unlock(&dir->i_mutex); printk(KERN_WARNING "%s: %s failed to populate directory %s\n", __FILE__, __FUNCTION__, parent->d_name.name); return -ENOMEM; } static int __rpc_mkdir(struct inode *dir, struct dentry *dentry) { struct inode *inode; inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUSR | S_IXUSR); if (!inode) goto out_err; inode->i_ino = iunique(dir->i_sb, 100); d_instantiate(dentry, inode); inc_nlink(dir); inode_dir_notify(dir, DN_CREATE); return 0; out_err: printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n", __FILE__, __FUNCTION__, dentry->d_name.name); return -ENOMEM; } static int __rpc_rmdir(struct inode *dir, struct dentry *dentry) { int error; shrink_dcache_parent(dentry); if (d_unhashed(dentry)) return 0; if ((error = simple_rmdir(dir, dentry)) != 0) return error; if (!error) { inode_dir_notify(dir, DN_DELETE); d_drop(dentry); } return 0; } static struct dentry * rpc_lookup_create(struct dentry *parent, const char *name, int len) { struct inode *dir = parent->d_inode; struct dentry *dentry; mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); dentry = lookup_one_len(name, parent, len); if (IS_ERR(dentry)) goto out_err; if (dentry->d_inode) { dput(dentry); dentry = ERR_PTR(-EEXIST); goto out_err; } return dentry; out_err: mutex_unlock(&dir->i_mutex); return dentry; } static struct dentry * rpc_lookup_negative(char *path, struct nameidata *nd) { struct dentry *dentry; int error; if ((error = rpc_lookup_parent(path, nd)) != 0) return ERR_PTR(error); dentry = rpc_lookup_create(nd->dentry, nd->last.name, nd->last.len); if (IS_ERR(dentry)) rpc_release_path(nd); return dentry; } struct dentry * rpc_mkdir(char *path, struct rpc_clnt *rpc_client) { struct nameidata nd; struct dentry *dentry; struct inode *dir; int error; dentry = rpc_lookup_negative(path, &nd); if (IS_ERR(dentry)) return dentry; dir = nd.dentry->d_inode; if ((error = __rpc_mkdir(dir, dentry)) != 0) goto err_dput; RPC_I(dentry->d_inode)->private = rpc_client; error = rpc_populate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF); if (error) goto err_depopulate; dget(dentry); out: mutex_unlock(&dir->i_mutex); rpc_release_path(&nd); return dentry; err_depopulate: rpc_depopulate(dentry); __rpc_rmdir(dir, dentry); err_dput: dput(dentry); printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n", __FILE__, __FUNCTION__, path, error); dentry = ERR_PTR(error); goto out; } int rpc_rmdir(struct dentry *dentry) { struct dentry *parent; struct inode *dir; int error; parent = dget_parent(dentry); dir = parent->d_inode; mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); rpc_depopulate(dentry); error = __rpc_rmdir(dir, dentry); dput(dentry); mutex_unlock(&dir->i_mutex); dput(parent); return error; } struct dentry * rpc_mkpipe(struct dentry *parent, const char *name, void *private, struct rpc_pipe_ops *ops, int flags) { struct dentry *dentry; struct inode *dir, *inode; struct rpc_inode *rpci; dentry = rpc_lookup_create(parent, name, strlen(name)); if (IS_ERR(dentry)) return dentry; dir = parent->d_inode; inode = rpc_get_inode(dir->i_sb, S_IFIFO | S_IRUSR | S_IWUSR); if (!inode) goto err_dput; inode->i_ino = iunique(dir->i_sb, 100); inode->i_fop = &rpc_pipe_fops; d_instantiate(dentry, inode); rpci = RPC_I(inode); rpci->private = private; rpci->flags = flags; rpci->ops = ops; inode_dir_notify(dir, DN_CREATE); dget(dentry); out: mutex_unlock(&dir->i_mutex); return dentry; err_dput: dput(dentry); dentry = ERR_PTR(-ENOMEM); printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n", __FILE__, __FUNCTION__, parent->d_name.name, name, -ENOMEM); goto out; } int rpc_unlink(struct dentry *dentry) { struct dentry *parent; struct inode *dir; int error = 0; parent = dget_parent(dentry); dir = parent->d_inode; mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); if (!d_unhashed(dentry)) { d_drop(dentry); if (dentry->d_inode) { rpc_close_pipes(dentry->d_inode); error = simple_unlink(dir, dentry); } inode_dir_notify(dir, DN_DELETE); } dput(dentry); mutex_unlock(&dir->i_mutex); dput(parent); return error; } /* * populate the filesystem */ static struct super_operations s_ops = { .alloc_inode = rpc_alloc_inode, .destroy_inode = rpc_destroy_inode, .statfs = simple_statfs, }; #define RPCAUTH_GSSMAGIC 0x67596969 static int rpc_fill_super(struct super_block *sb, void *data, int silent) { struct inode *inode; struct dentry *root; sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; sb->s_magic = RPCAUTH_GSSMAGIC; sb->s_op = &s_ops; sb->s_time_gran = 1; inode = rpc_get_inode(sb, S_IFDIR | 0755); if (!inode) return -ENOMEM; root = d_alloc_root(inode); if (!root) { iput(inode); return -ENOMEM; } if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF)) goto out; sb->s_root = root; return 0; out: d_genocide(root); dput(root); return -ENOMEM; } static int rpc_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt) { return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt); } static struct file_system_type rpc_pipe_fs_type = { .owner = THIS_MODULE, .name = "rpc_pipefs", .get_sb = rpc_get_sb, .kill_sb = kill_litter_super, }; static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) { struct rpc_inode *rpci = (struct rpc_inode *) foo; if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == SLAB_CTOR_CONSTRUCTOR) { inode_init_once(&rpci->vfs_inode); rpci->private = NULL; rpci->nreaders = 0; rpci->nwriters = 0; INIT_LIST_HEAD(&rpci->in_upcall); INIT_LIST_HEAD(&rpci->pipe); rpci->pipelen = 0; init_waitqueue_head(&rpci->waitq); INIT_WORK(&rpci->queue_timeout, rpc_timeout_upcall_queue, rpci); rpci->ops = NULL; } } int register_rpc_pipefs(void) { rpc_inode_cachep = kmem_cache_create("rpc_inode_cache", sizeof(struct rpc_inode), 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| SLAB_MEM_SPREAD), init_once, NULL); if (!rpc_inode_cachep) return -ENOMEM; register_filesystem(&rpc_pipe_fs_type); return 0; } void unregister_rpc_pipefs(void) { kmem_cache_destroy(rpc_inode_cachep); unregister_filesystem(&rpc_pipe_fs_type); }