/** * ecryptfs_miscdev_poll * @file: dev file (ignored) * @pt: dev poll table (ignored) * * Returns the poll mask */ static unsigned int ecryptfs_miscdev_poll(struct file *file, poll_table *pt) { struct ecryptfs_daemon *daemon; unsigned int mask = 0; uid_t euid = current_euid(); int rc; mutex_lock(&ecryptfs_daemon_hash_mux); /* TODO: Just use file->private_data? */ rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); BUG_ON(rc || !daemon); mutex_lock(&daemon->mux); mutex_unlock(&ecryptfs_daemon_hash_mux); if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) { printk(KERN_WARNING "%s: Attempt to poll on zombified " "daemon\n", __func__); goto out_unlock_daemon; } if (daemon->flags & ECRYPTFS_DAEMON_IN_READ) goto out_unlock_daemon; if (daemon->flags & ECRYPTFS_DAEMON_IN_POLL) goto out_unlock_daemon; daemon->flags |= ECRYPTFS_DAEMON_IN_POLL; mutex_unlock(&daemon->mux); poll_wait(file, &daemon->wait, pt); mutex_lock(&daemon->mux); if (!list_empty(&daemon->msg_ctx_out_queue)) mask |= POLLIN | POLLRDNORM; out_unlock_daemon: daemon->flags &= ~ECRYPTFS_DAEMON_IN_POLL; mutex_unlock(&daemon->mux); return mask; }
/** * ecryptfs_miscdev_release * @inode: inode of fs/ecryptfs/euid handle (ignored) * @file: file for fs/ecryptfs/euid handle (ignored) * * This keeps the daemon registered until the daemon sends another * ioctl to fs/ecryptfs/ctl or until the kernel module unregisters. * * Returns zero on success; non-zero otherwise */ static int ecryptfs_miscdev_release(struct inode *inode, struct file *file) { struct ecryptfs_daemon *daemon = NULL; uid_t euid = current_euid(); int rc; mutex_lock(&ecryptfs_daemon_hash_mux); rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); if (rc || !daemon) daemon = file->private_data; mutex_lock(&daemon->mux); BUG_ON(!(daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN)); daemon->flags &= ~ECRYPTFS_DAEMON_MISCDEV_OPEN; atomic_dec(&ecryptfs_num_miscdev_opens); mutex_unlock(&daemon->mux); rc = ecryptfs_exorcise_daemon(daemon); if (rc) { printk(KERN_CRIT "%s: Fatal error whilst attempting to " "shut down daemon; rc = [%d]. Please report this " "bug.\n", __func__, rc); BUG(); } module_put(THIS_MODULE); mutex_unlock(&ecryptfs_daemon_hash_mux); return rc; }
/** * ecryptfs_miscdev_open * @inode: inode of miscdev handle (ignored) * @file: file for miscdev handle * * Returns zero on success; non-zero otherwise */ static int ecryptfs_miscdev_open(struct inode *inode, struct file *file) { struct ecryptfs_daemon *daemon = NULL; int rc; mutex_lock(&ecryptfs_daemon_hash_mux); rc = ecryptfs_find_daemon_by_euid(&daemon); if (!rc) { rc = -EINVAL; goto out_unlock_daemon_list; } rc = ecryptfs_spawn_daemon(&daemon, file); if (rc) { printk(KERN_ERR "%s: Error attempting to spawn daemon; " "rc = [%d]\n", __func__, rc); goto out_unlock_daemon_list; } mutex_lock(&daemon->mux); if (daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) { rc = -EBUSY; goto out_unlock_daemon; } daemon->flags |= ECRYPTFS_DAEMON_MISCDEV_OPEN; file->private_data = daemon; atomic_inc(&ecryptfs_num_miscdev_opens); out_unlock_daemon: mutex_unlock(&daemon->mux); out_unlock_daemon_list: mutex_unlock(&ecryptfs_daemon_hash_mux); return rc; }
/** * ecryptfs_miscdev_open * @inode: inode of miscdev handle (ignored) * @file: file for miscdev handle (ignored) * * Returns zero on success; non-zero otherwise */ static int ecryptfs_miscdev_open(struct inode *inode, struct file *file) { struct ecryptfs_daemon *daemon = NULL; uid_t euid = current_euid(); int rc; mutex_lock(&ecryptfs_daemon_hash_mux); rc = try_module_get(THIS_MODULE); if (rc == 0) { rc = -EIO; printk(KERN_ERR "%s: Error attempting to increment module use " "count; rc = [%d]\n", __func__, rc); goto out_unlock_daemon_list; } rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); if (rc || !daemon) { rc = ecryptfs_spawn_daemon(&daemon, euid, current_user_ns(), task_pid(current)); if (rc) { printk(KERN_ERR "%s: Error attempting to spawn daemon; " "rc = [%d]\n", __func__, rc); goto out_module_put_unlock_daemon_list; } } mutex_lock(&daemon->mux); if (daemon->pid != task_pid(current)) { rc = -EINVAL; printk(KERN_ERR "%s: pid [0x%p] has registered with euid [%d], " "but pid [0x%p] has attempted to open the handle " "instead\n", __func__, daemon->pid, daemon->euid, task_pid(current)); goto out_unlock_daemon; } if (daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) { rc = -EBUSY; printk(KERN_ERR "%s: Miscellaneous device handle may only be " "opened once per daemon; pid [0x%p] already has this " "handle open\n", __func__, daemon->pid); goto out_unlock_daemon; } daemon->flags |= ECRYPTFS_DAEMON_MISCDEV_OPEN; file->private_data = daemon; atomic_inc(&ecryptfs_num_miscdev_opens); out_unlock_daemon: mutex_unlock(&daemon->mux); out_module_put_unlock_daemon_list: if (rc) module_put(THIS_MODULE); out_unlock_daemon_list: mutex_unlock(&ecryptfs_daemon_hash_mux); return rc; }
/** * ecryptfs_miscdev_read - format and send message from queue * @file: fs/ecryptfs/euid miscdevfs handle (ignored) * @buf: User buffer into which to copy the next message on the daemon queue * @count: Amount of space available in @buf * @ppos: Offset in file (ignored) * * Pulls the most recent message from the daemon queue, formats it for * being sent via a miscdevfs handle, and copies it into @buf * * Returns the number of bytes copied into the user buffer */ static ssize_t ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { struct ecryptfs_daemon *daemon; struct ecryptfs_msg_ctx *msg_ctx; size_t packet_length_size; char packet_length[3]; size_t i; size_t total_length; uid_t euid = current_euid(); int rc; mutex_lock(&ecryptfs_daemon_hash_mux); /* TODO: Just use file->private_data? */ rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns()); if (rc || !daemon) { mutex_unlock(&ecryptfs_daemon_hash_mux); return -EINVAL; } mutex_lock(&daemon->mux); if (task_pid(current) != daemon->pid) { mutex_unlock(&daemon->mux); mutex_unlock(&ecryptfs_daemon_hash_mux); return -EPERM; } if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) { rc = 0; mutex_unlock(&ecryptfs_daemon_hash_mux); printk(KERN_WARNING "%s: Attempt to read from zombified " "daemon\n", __func__); goto out_unlock_daemon; } if (daemon->flags & ECRYPTFS_DAEMON_IN_READ) { rc = 0; mutex_unlock(&ecryptfs_daemon_hash_mux); goto out_unlock_daemon; } /* This daemon will not go away so long as this flag is set */ daemon->flags |= ECRYPTFS_DAEMON_IN_READ; mutex_unlock(&ecryptfs_daemon_hash_mux); check_list: if (list_empty(&daemon->msg_ctx_out_queue)) { mutex_unlock(&daemon->mux); rc = wait_event_interruptible( daemon->wait, !list_empty(&daemon->msg_ctx_out_queue)); mutex_lock(&daemon->mux); if (rc < 0) { rc = 0; goto out_unlock_daemon; } } if (daemon->flags & ECRYPTFS_DAEMON_ZOMBIE) { rc = 0; goto out_unlock_daemon; } if (list_empty(&daemon->msg_ctx_out_queue)) { /* Something else jumped in since the * wait_event_interruptable() and removed the * message from the queue; try again */ goto check_list; } msg_ctx = list_first_entry(&daemon->msg_ctx_out_queue, struct ecryptfs_msg_ctx, daemon_out_list); BUG_ON(!msg_ctx); mutex_lock(&msg_ctx->mux); if (msg_ctx->msg) { rc = ecryptfs_write_packet_length(packet_length, msg_ctx->msg_size, &packet_length_size); if (rc) { rc = 0; printk(KERN_WARNING "%s: Error writing packet length; " "rc = [%d]\n", __func__, rc); goto out_unlock_msg_ctx; } } else { packet_length_size = 0; msg_ctx->msg_size = 0; } /* miscdevfs packet format: * Octet 0: Type * Octets 1-4: network byte order msg_ctx->counter * Octets 5-N0: Size of struct ecryptfs_message to follow * Octets N0-N1: struct ecryptfs_message (including data) * * Octets 5-N1 not written if the packet type does not * include a message */ total_length = (1 + 4 + packet_length_size + msg_ctx->msg_size); if (count < total_length) { rc = 0; printk(KERN_WARNING "%s: Only given user buffer of " "size [%zd], but we need [%zd] to read the " "pending message\n", __func__, count, total_length); goto out_unlock_msg_ctx; } rc = -EFAULT; if (put_user(msg_ctx->type, buf)) goto out_unlock_msg_ctx; if (put_user(cpu_to_be32(msg_ctx->counter), (__be32 __user *)(buf + 1))) goto out_unlock_msg_ctx; i = 5; if (msg_ctx->msg) { if (copy_to_user(&buf[i], packet_length, packet_length_size)) goto out_unlock_msg_ctx; i += packet_length_size; if (copy_to_user(&buf[i], msg_ctx->msg, msg_ctx->msg_size)) goto out_unlock_msg_ctx; i += msg_ctx->msg_size; } rc = i; list_del(&msg_ctx->daemon_out_list); kfree(msg_ctx->msg); msg_ctx->msg = NULL; /* We do not expect a reply from the userspace daemon for any * message type other than ECRYPTFS_MSG_REQUEST */ if (msg_ctx->type != ECRYPTFS_MSG_REQUEST) ecryptfs_msg_ctx_alloc_to_free(msg_ctx); out_unlock_msg_ctx: mutex_unlock(&msg_ctx->mux); out_unlock_daemon: daemon->flags &= ~ECRYPTFS_DAEMON_IN_READ; mutex_unlock(&daemon->mux); return rc; }