/* $Id: capifs.c,v 1.1.2.3 2004/01/16 21:09:26 keil Exp $ * * Copyright 2000 by Carsten Paeth <calle@calle.de> * * Heavily based on devpts filesystem from H. Peter Anvin * * This software may be used and distributed according to the terms * of the GNU General Public License, incorporated herein by reference. * */ #include <linux/fs.h> #include <linux/mount.h> #include <linux/namei.h> #include <linux/module.h> #include <linux/init.h> #include <linux/ctype.h> #include <linux/sched.h> /* current */ #include "capifs.h" MODULE_DESCRIPTION("CAPI4Linux: /dev/capi/ filesystem"); MODULE_AUTHOR("Carsten Paeth"); MODULE_LICENSE("GPL"); /* ------------------------------------------------------------------ */ static char *revision = "$Revision: 1.1.2.3 $"; /* ------------------------------------------------------------------ */ #define CAPIFS_SUPER_MAGIC (('C'<<8)|'N') static struct vfsmount *capifs_mnt; static struct dentry *capifs_root; static struct { int setuid; int setgid; uid_t uid; gid_t gid; umode_t mode; } config = {.mode = 0600}; /* ------------------------------------------------------------------ */ static int capifs_remount(struct super_block *s, int *flags, char *data) { int setuid = 0; int setgid = 0; uid_t uid = 0; gid_t gid = 0; umode_t mode = 0600; char *this_char; this_char = NULL; while ((this_char = strsep(&data, ",")) != NULL) { int n; char dummy; if (!*this_char) continue; if (sscanf(this_char, "uid=%i%c", &n, &dummy) == 1) { setuid = 1; uid = n; } else if (sscanf(this_char, "gid=%i%c", &n, &dummy) == 1) { setgid = 1; gid = n; } else if (sscanf(this_char, "mode=%o%c", &n, &dummy) == 1) mode = n & ~S_IFMT; else { printk("capifs: called with bogus options\n"); return -EINVAL; } } config.setuid = setuid; config.setgid = setgid; config.uid = uid; config.gid = gid; config.mode = mode; return 0; } static struct super_operations capifs_sops = { .statfs = simple_statfs, .remount_fs = capifs_remount, }; static int capifs_fill_super(struct super_block *s, void *data, int silent) { struct inode * inode; s->s_blocksize = 1024; s->s_blocksize_bits = 10; s->s_magic = CAPIFS_SUPER_MAGIC; s->s_op = &capifs_sops; s->s_time_gran = 1; inode = new_inode(s); if (!inode) goto fail; inode->i_ino = 1; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; inode->i_blocks = 0; inode->i_uid = inode->i_gid = 0; inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR; inode->i_op = &simple_dir_inode_operations; inode->i_fop = &simple_dir_operations; inode->i_nlink = 2; capifs_root = s->s_root = d_alloc_root(inode); if (s->s_root) return 0; printk("capifs: get root dentry failed\n"); iput(inode); fail: return -ENOMEM; } static int capifs_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, capifs_fill_super, mnt); } static struct file_system_type capifs_fs_type = { .owner = THIS_MODULE, .name = "capifs", .get_sb = capifs_get_sb, .kill_sb = kill_anon_super, }; static struct dentry *get_node(int num) { char s[10]; struct dentry *root = capifs_root; mutex_lock(&root->d_inode->i_mutex); return lookup_one_len(s, root, sprintf(s, "%d", num)); } void capifs_new_ncci(unsigned int number, dev_t device) { struct dentry *dentry; struct inode *inode = new_inode(capifs_mnt->mnt_sb); if (!inode) return; inode->i_ino = number+2; inode->i_uid = config.setuid ? config.uid : current->fsuid; inode->i_gid = config.setgid ? config.gid : current->fsgid; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; init_special_inode(inode, S_IFCHR|config.mode, device); //inode->i_op = &capifs_file_inode_operations; dentry = get_node(number); if (!IS_ERR(dentry) && !dentry->d_inode) d_instantiate(dentry, inode); mutex_unlock(&capifs_root->d_inode->i_mutex); } void capifs_free_ncci(unsigned int number) { struct dentry *dentry = get_node(number); if (!IS_ERR(dentry)) { struct inode *inode = dentry->d_inode; if (inode) { inode->i_nlink--; d_delete(dentry); dput(dentry); } dput(dentry); } mutex_unlock(&capifs_root->d_inode->i_mutex); } static int __init capifs_init(void) { char rev[32]; char *p; int err; if ((p = strchr(revision, ':')) != 0 && p[1]) { strlcpy(rev, p + 2, sizeof(rev)); if ((p = strchr(rev, '$')) != 0 && p > rev) *(p-1) = 0; } else strcpy(rev, "1.0"); err = register_filesystem(&capifs_fs_type); if (!err) { capifs_mnt = kern_mount(&capifs_fs_type); if (IS_ERR(capifs_mnt)) { err = PTR_ERR(capifs_mnt); unregister_filesystem(&capifs_fs_type); } } if (!err) printk(KERN_NOTICE "capifs: Rev %s\n", rev); return err; } static void __exit capifs_exit(void) { unregister_filesystem(&capifs_fs_type); mntput(capifs_mnt); } EXPORT_SYMBOL(capifs_new_ncci); EXPORT_SYMBOL(capifs_free_ncci); module_init(capifs_init); module_exit(capifs_exit);