original development tree for Linux kernel GTP module; now long in mainline.
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/*
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <linux/ctype.h>
#include <linux/dcache.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/slab.h>
#include <linux/statfs.h>
#include <linux/types.h>
#include <linux/pid_namespace.h>
#include <linux/namei.h>
#include <asm/uaccess.h>
#include <os.h>
static struct inode *get_inode(struct super_block *, struct 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 const struct super_operations hppfs_sbops;
static int is_pid(struct dentry *dentry)
{
struct super_block *sb;
int i;
sb = dentry->d_sb;
if (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;
}
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(KERN_ERR "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 struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
unsigned int flags)
{
struct dentry *proc_dentry, *parent;
struct qstr *name = &dentry->d_name;
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);
parent = HPPFS_I(ino)->proc_dentry;
mutex_lock(&parent->d_inode->i_mutex);
proc_dentry = lookup_one_len(name->name, parent, name->len);
mutex_unlock(&parent->d_inode->i_mutex);
if (IS_ERR(proc_dentry))
return proc_dentry;
err = -ENOMEM;
inode = get_inode(ino->i_sb, proc_dentry);
if (!inode)
goto out;
d_add(dentry, inode);
return NULL;
out:
return ERR_PTR(err);
}
static const struct inode_operations hppfs_file_iops = {
};
static ssize_t read_proc(struct file *file, char __user *buf, ssize_t count,
loff_t *ppos, int is_user)
{
ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
ssize_t n;
read = file_inode(file)->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 __user *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(KERN_ERR "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(KERN_ERR "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 __user *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) {
int rem;
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;
rem = copy_to_user(buf, &data->contents[off], count);
*ppos += count - rem;
if (rem > 0)
return -EFAULT;
} else if (hppfs->host_fd != -1) {
err = os_seek_file(hppfs->host_fd, *ppos);
if (err) {
printk(KERN_ERR "hppfs_read : seek failed, "
"errno = %d\n", err);
return err;
}
err = hppfs_read_file(hppfs->host_fd, buf, count);
if (err < 0) {
printk(KERN_ERR "hppfs_read: read failed: %d\n", err);
return err;
}
count = err;
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 __user *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 __user *, size_t, loff_t *);
write = file_inode(proc_file)->i_fop->write;
return (*write)(proc_file, buf, len, ppos);
}
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(KERN_ERR "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(KERN_ERR "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(KERN_ERR "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(KERN_ERR "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)
{
const struct cred *cred = file->f_cred;
struct hppfs_private *data;
struct path path;
char *host_file;
int err, fd, type, filter;
err = -ENOMEM;
data = hppfs_data();
if (data == NULL)
goto out;
host_file = dentry_name(file->f_path.dentry, strlen("/rw"));
if (host_file == NULL)
goto out_free2;
path.mnt = inode->i_sb->s_fs_info;
path.dentry = HPPFS_I(inode)->proc_dentry;
/* XXX This isn't closed anywhere */
data->proc_file = dentry_open(&path, file_mode(file->f_mode), cred);
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(KERN_ERR "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(KERN_ERR "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)
{
const struct cred *cred = file->f_cred;
struct hppfs_private *data;
struct path path;
int err;
err = -ENOMEM;
data = hppfs_data();
if (data == NULL)
goto out;
path.mnt = inode->i_sb->s_fs_info;
path.dentry = HPPFS_I(inode)->proc_dentry;
data->proc_file = dentry_open(&path, file_mode(file->f_mode), cred);
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 = file_inode(proc_file)->i_fop->llseek;
if (llseek != NULL) {
ret = (*llseek)(proc_file, off, where);
if (ret < 0)
return ret;
}
return default_llseek(file, off, where);
}
static const 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, u64 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_path.dentry
});
int err;
readdir = file_inode(proc_file)->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, loff_t start, loff_t end,
int datasync)
{
return filemap_write_and_wait_range(file->f_mapping, start, end);
}
static const struct file_operations hppfs_dir_fops = {
.owner = NULL,
.readdir = hppfs_readdir,
.open = hppfs_dir_open,
.fsync = hppfs_fsync,
.llseek = default_llseek,
};
static int hppfs_statfs(struct dentry *dentry, 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)
return NULL;
hi->proc_dentry = NULL;
inode_init_once(&hi->vfs_inode);
return &hi->vfs_inode;
}
void hppfs_evict_inode(struct inode *ino)
{
clear_inode(ino);
dput(HPPFS_I(ino)->proc_dentry);
mntput(ino->i_sb->s_fs_info);
}
static void hppfs_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
kfree(HPPFS_I(inode));
}
static void hppfs_destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, hppfs_i_callback);
}
static const struct super_operations hppfs_sbops = {
.alloc_inode = hppfs_alloc_inode,
.destroy_inode = hppfs_destroy_inode,
.evict_inode = hppfs_evict_inode,
.statfs = hppfs_statfs,
};
static int hppfs_readlink(struct dentry *dentry, char __user *buffer,
int buflen)
{
struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
return proc_dentry->d_inode->i_op->readlink(proc_dentry, buffer,
buflen);
}
static void *hppfs_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
return proc_dentry->d_inode->i_op->follow_link(proc_dentry, nd);
}
static void hppfs_put_link(struct dentry *dentry, struct nameidata *nd,
void *cookie)
{
struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
if (proc_dentry->d_inode->i_op->put_link)
proc_dentry->d_inode->i_op->put_link(proc_dentry, nd, cookie);
}
static const struct inode_operations hppfs_dir_iops = {
.lookup = hppfs_lookup,
};
static const struct inode_operations hppfs_link_iops = {
.readlink = hppfs_readlink,
.follow_link = hppfs_follow_link,
.put_link = hppfs_put_link,
};
static struct inode *get_inode(struct super_block *sb, struct dentry *dentry)
{
struct inode *proc_ino = dentry->d_inode;
struct inode *inode = new_inode(sb);
if (!inode) {
dput(dentry);
return NULL;
}
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;
inode->i_uid = proc_ino->i_uid;
inode->i_gid = proc_ino->i_gid;
inode->i_atime = proc_ino->i_atime;
inode->i_mtime = proc_ino->i_mtime;
inode->i_ctime = proc_ino->i_ctime;
inode->i_ino = proc_ino->i_ino;
inode->i_mode = proc_ino->i_mode;
set_nlink(inode, proc_ino->i_nlink);
inode->i_size = proc_ino->i_size;
inode->i_blocks = proc_ino->i_blocks;
return inode;
}
static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
{
struct inode *root_inode;
struct vfsmount *proc_mnt;
int err = -ENOENT;
proc_mnt = mntget(task_active_pid_ns(current)->proc_mnt);
if (IS_ERR(proc_mnt))
goto out;
sb->s_blocksize = 1024;
sb->s_blocksize_bits = 10;
sb->s_magic = HPPFS_SUPER_MAGIC;
sb->s_op = &hppfs_sbops;
sb->s_fs_info = proc_mnt;
err = -ENOMEM;
root_inode = get_inode(sb, dget(proc_mnt->mnt_root));
sb->s_root = d_make_root(root_inode);
if (!sb->s_root)
goto out_mntput;
return 0;
out_mntput:
mntput(proc_mnt);
out:
return(err);
}
static struct dentry *hppfs_read_super(struct file_system_type *type,
int flags, const char *dev_name,
void *data)
{
return mount_nodev(type, flags, data, hppfs_fill_super);
}
static struct file_system_type hppfs_type = {
.owner = THIS_MODULE,
.name = "hppfs",
.mount = hppfs_read_super,
.kill_sb = kill_anon_super,
.fs_flags = 0,
};
MODULE_ALIAS_FS("hppfs");
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");