/* * Copyright (C) 2002 Jeff Dike (jdike@karaya.com) * Licensed under the GPL */ #include <linux/fs.h> #include <linux/file.h> #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/list.h> #include <linux/kernel.h> #include <linux/ctype.h> #include <linux/dcache.h> #include <linux/statfs.h> #include <asm/uaccess.h> #include <asm/fcntl.h> #include "os.h" static int init_inode(struct inode *inode, struct dentry *dentry); struct hppfs_data { struct list_head list; char contents[PAGE_SIZE - sizeof(struct list_head)]; }; struct hppfs_private { struct file *proc_file; int host_fd; loff_t len; struct hppfs_data *contents; }; struct hppfs_inode_info { struct dentry *proc_dentry; struct inode vfs_inode; }; static inline struct hppfs_inode_info *HPPFS_I(struct inode *inode) { return container_of(inode, struct hppfs_inode_info, vfs_inode); } #define HPPFS_SUPER_MAGIC 0xb00000ee static struct super_operations hppfs_sbops; static int is_pid(struct dentry *dentry) { struct super_block *sb; int i; sb = dentry->d_sb; if((sb->s_op != &hppfs_sbops) || (dentry->d_parent != sb->s_root)) return(0); for(i = 0; i < dentry->d_name.len; i++){ if(!isdigit(dentry->d_name.name[i])) return(0); } return(1); } static char *dentry_name(struct dentry *dentry, int extra) { struct dentry *parent; char *root, *name; const char *seg_name; int len, seg_len; len = 0; parent = dentry; while(parent->d_parent != parent){ if(is_pid(parent)) len += strlen("pid") + 1; else len += parent->d_name.len + 1; parent = parent->d_parent; } root = "proc"; len += strlen(root); name = kmalloc(len + extra + 1, GFP_KERNEL); if(name == NULL) return(NULL); name[len] = '\0'; parent = dentry; while(parent->d_parent != parent){ if(is_pid(parent)){ seg_name = "pid"; seg_len = strlen("pid"); } else { seg_name = parent->d_name.name; seg_len = parent->d_name.len; } len -= seg_len + 1; name[len] = '/'; strncpy(&name[len + 1], seg_name, seg_len); parent = parent->d_parent; } strncpy(name, root, strlen(root)); return(name); } struct dentry_operations hppfs_dentry_ops = { }; static int file_removed(struct dentry *dentry, const char *file) { char *host_file; int extra, fd; extra = 0; if(file != NULL) extra += strlen(file) + 1; host_file = dentry_name(dentry, extra + strlen("/remove")); if(host_file == NULL){ printk("file_removed : allocation failed\n"); return(-ENOMEM); } if(file != NULL){ strcat(host_file, "/"); strcat(host_file, file); } strcat(host_file, "/remove"); fd = os_open_file(host_file, of_read(OPENFLAGS()), 0); kfree(host_file); if(fd > 0){ os_close_file(fd); return(1); } return(0); } static void hppfs_read_inode(struct inode *ino) { struct inode *proc_ino; if(HPPFS_I(ino)->proc_dentry == NULL) return; proc_ino = HPPFS_I(ino)->proc_dentry->d_inode; ino->i_uid = proc_ino->i_uid; ino->i_gid = proc_ino->i_gid; ino->i_atime = proc_ino->i_atime; ino->i_mtime = proc_ino->i_mtime; ino->i_ctime = proc_ino->i_ctime; ino->i_ino = proc_ino->i_ino; ino->i_mode = proc_ino->i_mode; ino->i_nlink = proc_ino->i_nlink; ino->i_size = proc_ino->i_size; ino->i_blksize = proc_ino->i_blksize; ino->i_blocks = proc_ino->i_blocks; } static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry, struct nameidata *nd) { struct dentry *proc_dentry, *new, *parent; struct inode *inode; int err, deleted; deleted = file_removed(dentry, NULL); if(deleted < 0) return(ERR_PTR(deleted)); else if(deleted) return(ERR_PTR(-ENOENT)); err = -ENOMEM; parent = HPPFS_I(ino)->proc_dentry; down(&parent->d_inode->i_sem); proc_dentry = d_lookup(parent, &dentry->d_name); if(proc_dentry == NULL){ proc_dentry = d_alloc(parent, &dentry->d_name); if(proc_dentry == NULL){ up(&parent->d_inode->i_sem); goto out; } new = (*parent->d_inode->i_op->lookup)(parent->d_inode, proc_dentry, NULL); if(new){ dput(proc_dentry); proc_dentry = new; } } up(&parent->d_inode->i_sem); if(IS_ERR(proc_dentry)) return(proc_dentry); inode = iget(ino->i_sb, 0); if(inode == NULL) goto out_dput; err = init_inode(inode, proc_dentry); if(err) goto out_put; hppfs_read_inode(inode); d_add(dentry, inode); dentry->d_op = &hppfs_dentry_ops; return(NULL); out_put: iput(inode); out_dput: dput(proc_dentry); out: return(ERR_PTR(err)); } static struct inode_operations hppfs_file_iops = { }; static ssize_t read_proc(struct file *file, char *buf, ssize_t count, loff_t *ppos, int is_user) { ssize_t (*read)(struct file *, char *, size_t, loff_t *); ssize_t n; read = file->f_dentry->d_inode->i_fop->read; if(!is_user) set_fs(KERNEL_DS); n = (*read)(file, buf, count, &file->f_pos); if(!is_user) set_fs(USER_DS); if(ppos) *ppos = file->f_pos; return n; } static ssize_t hppfs_read_file(int fd, char *buf, ssize_t count) { ssize_t n; int cur, err; char *new_buf; n = -ENOMEM; new_buf = kmalloc(PAGE_SIZE, GFP_KERNEL); if(new_buf == NULL){ printk("hppfs_read_file : kmalloc failed\n"); goto out; } n = 0; while(count > 0){ cur = min_t(ssize_t, count, PAGE_SIZE); err = os_read_file(fd, new_buf, cur); if(err < 0){ printk("hppfs_read : read failed, errno = %d\n", err); n = err; goto out_free; } else if(err == 0) break; if(copy_to_user(buf, new_buf, err)){ n = -EFAULT; goto out_free; } n += err; count -= err; } out_free: kfree(new_buf); out: return n; } static ssize_t hppfs_read(struct file *file, char *buf, size_t count, loff_t *ppos) { struct hppfs_private *hppfs = file->private_data; struct hppfs_data *data; loff_t off; int err; if(hppfs->contents != NULL){ if(*ppos >= hppfs->len) return(0); data = hppfs->contents; off = *ppos; while(off >= sizeof(data->contents)){ data = list_entry(data->list.next, struct hppfs_data, list); off -= sizeof(data->contents); } if(off + count > hppfs->len) count = hppfs->len - off; copy_to_user(buf, &data->contents[off], count); *ppos += count; } else if(hppfs->host_fd != -1){ err = os_seek_file(hppfs->host_fd, *ppos); if(err){ printk("hppfs_read : seek failed, errno = %d\n", err); return(err); } count = hppfs_read_file(hppfs->host_fd, buf, count); if(count > 0) *ppos += count; } else count = read_proc(hppfs->proc_file, buf, count, ppos, 1); return(count); } static ssize_t hppfs_write(struct file *file, const char *buf, size_t len, loff_t *ppos) { struct hppfs_private *data = file->private_data; struct file *proc_file = data->proc_file; ssize_t (*write)(struct file *, const char *, size_t, loff_t *); int err; write = proc_file->f_dentry->d_inode->i_fop->write; proc_file->f_pos = file->f_pos; err = (*write)(proc_file, buf, len, &proc_file->f_pos); file->f_pos = proc_file->f_pos; return(err); } static int open_host_sock(char *host_file, int *filter_out) { char *end; int fd; end = &host_file[strlen(host_file)]; strcpy(end, "/rw"); *filter_out = 1; fd = os_connect_socket(host_file); if(fd > 0) return(fd); strcpy(end, "/r"); *filter_out = 0; fd = os_connect_socket(host_file); return(fd); } static void free_contents(struct hppfs_data *head) { struct hppfs_data *data; struct list_head *ele, *next; if(head == NULL) return; list_for_each_safe(ele, next, &head->list){ data = list_entry(ele, struct hppfs_data, list); kfree(data); } kfree(head); } static struct hppfs_data *hppfs_get_data(int fd, int filter, struct file *proc_file, struct file *hppfs_file, loff_t *size_out) { struct hppfs_data *data, *new, *head; int n, err; err = -ENOMEM; data = kmalloc(sizeof(*data), GFP_KERNEL); if(data == NULL){ printk("hppfs_get_data : head allocation failed\n"); goto failed; } INIT_LIST_HEAD(&data->list); head = data; *size_out = 0; if(filter){ while((n = read_proc(proc_file, data->contents, sizeof(data->contents), NULL, 0)) > 0) os_write_file(fd, data->contents, n); err = os_shutdown_socket(fd, 0, 1); if(err){ printk("hppfs_get_data : failed to shut down " "socket\n"); goto failed_free; } } while(1){ n = os_read_file(fd, data->contents, sizeof(data->contents)); if(n < 0){ err = n; printk("hppfs_get_data : read failed, errno = %d\n", err); goto failed_free; } else if(n == 0) break; *size_out += n; if(n < sizeof(data->contents)) break; new = kmalloc(sizeof(*data), GFP_KERNEL); if(new == 0){ printk("hppfs_get_data : data allocation failed\n"); err = -ENOMEM; goto failed_free; } INIT_LIST_HEAD(&new->list); list_add(&new->list, &data->list); data = new; } return(head); failed_free: free_contents(head); failed: return(ERR_PTR(err)); } static struct hppfs_private *hppfs_data(void) { struct hppfs_private *data; data = kmalloc(sizeof(*data), GFP_KERNEL); if(data == NULL) return(data); *data = ((struct hppfs_private ) { .host_fd = -1, .len = -1, .contents = NULL } ); return(data); } static int file_mode(int fmode) { if(fmode == (FMODE_READ | FMODE_WRITE)) return(O_RDWR); if(fmode == FMODE_READ) return(O_RDONLY); if(fmode == FMODE_WRITE) return(O_WRONLY); return(0); } static int hppfs_open(struct inode *inode, struct file *file) { struct hppfs_private *data; struct dentry *proc_dentry; char *host_file; int err, fd, type, filter; err = -ENOMEM; data = hppfs_data(); if(data == NULL) goto out; host_file = dentry_name(file->f_dentry, strlen("/rw")); if(host_file == NULL) goto out_free2; proc_dentry = HPPFS_I(inode)->proc_dentry; /* XXX This isn't closed anywhere */ data->proc_file = dentry_open(dget(proc_dentry), NULL, file_mode(file->f_mode)); err = PTR_ERR(data->proc_file); if(IS_ERR(data->proc_file)) goto out_free1; type = os_file_type(host_file); if(type == OS_TYPE_FILE){ fd = os_open_file(host_file, of_read(OPENFLAGS()), 0); if(fd >= 0) data->host_fd = fd; else printk("hppfs_open : failed to open '%s', errno = %d\n", host_file, -fd); data->contents = NULL; } else if(type == OS_TYPE_DIR){ fd = open_host_sock(host_file, &filter); if(fd > 0){ data->contents = hppfs_get_data(fd, filter, data->proc_file, file, &data->len); if(!IS_ERR(data->contents)) data->host_fd = fd; } else printk("hppfs_open : failed to open a socket in " "'%s', errno = %d\n", host_file, -fd); } kfree(host_file); file->private_data = data; return(0); out_free1: kfree(host_file); out_free2: free_contents(data->contents); kfree(data); out: return(err); } static int hppfs_dir_open(struct inode *inode, struct file *file) { struct hppfs_private *data; struct dentry *proc_dentry; int err; err = -ENOMEM; data = hppfs_data(); if(data == NULL) goto out; proc_dentry = HPPFS_I(inode)->proc_dentry; data->proc_file = dentry_open(dget(proc_dentry), NULL, file_mode(file->f_mode)); err = PTR_ERR(data->proc_file); if(IS_ERR(data->proc_file)) goto out_free; file->private_data = data; return(0); out_free: kfree(data); out: return(err); } static loff_t hppfs_llseek(struct file *file, loff_t off, int where) { struct hppfs_private *data = file->private_data; struct file *proc_file = data->proc_file; loff_t (*llseek)(struct file *, loff_t, int); loff_t ret; llseek = proc_file->f_dentry->d_inode->i_fop->llseek; if(llseek != NULL){ ret = (*llseek)(proc_file, off, where); if(ret < 0) return(ret); } return(default_llseek(file, off, where)); } static struct file_operations hppfs_file_fops = { .owner = NULL, .llseek = hppfs_llseek, .read = hppfs_read, .write = hppfs_write, .open = hppfs_open, }; struct hppfs_dirent { void *vfs_dirent; filldir_t filldir; struct dentry *dentry; }; static int hppfs_filldir(void *d, const char *name, int size, loff_t offset, ino_t inode, unsigned int type) { struct hppfs_dirent *dirent = d; if(file_removed(dirent->dentry, name)) return(0); return((*dirent->filldir)(dirent->vfs_dirent, name, size, offset, inode, type)); } static int hppfs_readdir(struct file *file, void *ent, filldir_t filldir) { struct hppfs_private *data = file->private_data; struct file *proc_file = data->proc_file; int (*readdir)(struct file *, void *, filldir_t); struct hppfs_dirent dirent = ((struct hppfs_dirent) { .vfs_dirent = ent, .filldir = filldir, .dentry = file->f_dentry } ); int err; readdir = proc_file->f_dentry->d_inode->i_fop->readdir; proc_file->f_pos = file->f_pos; err = (*readdir)(proc_file, &dirent, hppfs_filldir); file->f_pos = proc_file->f_pos; return(err); } static int hppfs_fsync(struct file *file, struct dentry *dentry, int datasync) { return(0); } static struct file_operations hppfs_dir_fops = { .owner = NULL, .readdir = hppfs_readdir, .open = hppfs_dir_open, .fsync = hppfs_fsync, }; static int hppfs_statfs(struct super_block *sb, struct kstatfs *sf) { sf->f_blocks = 0; sf->f_bfree = 0; sf->f_bavail = 0; sf->f_files = 0; sf->f_ffree = 0; sf->f_type = HPPFS_SUPER_MAGIC; return(0); } static struct inode *hppfs_alloc_inode(struct super_block *sb) { struct hppfs_inode_info *hi; hi = kmalloc(sizeof(*hi), GFP_KERNEL); if(hi == NULL) return(NULL); *hi = ((struct hppfs_inode_info) { .proc_dentry = NULL }); inode_init_once(&hi->vfs_inode); return(&hi->vfs_inode); } void hppfs_delete_inode(struct inode *ino) { clear_inode(ino); } static void hppfs_destroy_inode(struct inode *inode) { kfree(HPPFS_I(inode)); } static struct super_operations hppfs_sbops = { .alloc_inode = hppfs_alloc_inode, .destroy_inode = hppfs_destroy_inode, .read_inode = hppfs_read_inode, .delete_inode = hppfs_delete_inode, .statfs = hppfs_statfs, }; static int hppfs_readlink(struct dentry *dentry, char *buffer, int buflen) { struct file *proc_file; struct dentry *proc_dentry; int ret; proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry; proc_file = dentry_open(dget(proc_dentry), NULL, O_RDONLY); if (IS_ERR(proc_file)) return PTR_ERR(proc_file); ret = proc_dentry->d_inode->i_op->readlink(proc_dentry, buffer, buflen); fput(proc_file); return ret; } static void* hppfs_follow_link(struct dentry *dentry, struct nameidata *nd) { struct file *proc_file; struct dentry *proc_dentry; void *ret; proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry; proc_file = dentry_open(dget(proc_dentry), NULL, O_RDONLY); if (IS_ERR(proc_file)) return proc_file; ret = proc_dentry->d_inode->i_op->follow_link(proc_dentry, nd); fput(proc_file); return ret; } static struct inode_operations hppfs_dir_iops = { .lookup = hppfs_lookup, }; static struct inode_operations hppfs_link_iops = { .readlink = hppfs_readlink, .follow_link = hppfs_follow_link, }; static int init_inode(struct inode *inode, struct dentry *dentry) { if(S_ISDIR(dentry->d_inode->i_mode)){ inode->i_op = &hppfs_dir_iops; inode->i_fop = &hppfs_dir_fops; } else if(S_ISLNK(dentry->d_inode->i_mode)){ inode->i_op = &hppfs_link_iops; inode->i_fop = &hppfs_file_fops; } else { inode->i_op = &hppfs_file_iops; inode->i_fop = &hppfs_file_fops; } HPPFS_I(inode)->proc_dentry = dentry; return(0); } static int hppfs_fill_super(struct super_block *sb, void *d, int silent) { struct inode *root_inode; struct file_system_type *procfs; struct super_block *proc_sb; int err; err = -ENOENT; procfs = get_fs_type("proc"); if(procfs == NULL) goto out; if(list_empty(&procfs->fs_supers)) goto out; proc_sb = list_entry(procfs->fs_supers.next, struct super_block, s_instances); sb->s_blocksize = 1024; sb->s_blocksize_bits = 10; sb->s_magic = HPPFS_SUPER_MAGIC; sb->s_op = &hppfs_sbops; root_inode = iget(sb, 0); if(root_inode == NULL) goto out; err = init_inode(root_inode, proc_sb->s_root); if(err) goto out_put; err = -ENOMEM; sb->s_root = d_alloc_root(root_inode); if(sb->s_root == NULL) goto out_put; hppfs_read_inode(root_inode); return(0); out_put: iput(root_inode); out: return(err); } static struct super_block *hppfs_read_super(struct file_system_type *type, int flags, const char *dev_name, void *data) { return(get_sb_nodev(type, flags, data, hppfs_fill_super)); } static struct file_system_type hppfs_type = { .owner = THIS_MODULE, .name = "hppfs", .get_sb = hppfs_read_super, .kill_sb = kill_anon_super, .fs_flags = 0, }; static int __init init_hppfs(void) { return(register_filesystem(&hppfs_type)); } static void __exit exit_hppfs(void) { unregister_filesystem(&hppfs_type); } module_init(init_hppfs) module_exit(exit_hppfs) MODULE_LICENSE("GPL"); /* * Overrides for Emacs so that we follow Linus's tabbing style. * Emacs will notice this stuff at the end of the file and automatically * adjust the settings for this buffer only. This must remain at the end * of the file. * --------------------------------------------------------------------------- * Local variables: * c-file-style: "linux" * End: */