patch-2.3.99-pre3 linux/drivers/isdn/avmb1/capifs.c

• Lines: 596
• Date: Thu Mar 23 23:18:20 2000
• Orig file: v2.3.99-pre2/linux/drivers/isdn/avmb1/capifs.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.99-pre2/linux/drivers/isdn/avmb1/capifs.c linux/drivers/isdn/avmb1/capifs.c
@@ -0,0 +1,595 @@
+/*
+ * $Id: capifs.c,v 1.5 2000/03/13 17:49:52 calle Exp $
+ * 
+ * (c) Copyright 2000 by Carsten Paeth (calle@calle.de)
+ *
+ * Heavily based on devpts filesystem from H. Peter Anvin
+ * 
+ * $Log: capifs.c,v $
+ * Revision 1.5  2000/03/13 17:49:52  calle
+ * make it running with 2.3.51.
+ *
+ * Revision 1.4  2000/03/08 17:06:33  calle
+ * - changes for devfs and 2.3.49
+ * - capifs now configurable (no need with devfs)
+ * - New Middleware ioctl CAPI_NCCI_GETUNIT
+ * - Middleware again tested with 2.2.14 and 2.3.49 (with and without devfs)
+ *
+ * Revision 1.3  2000/03/06 18:00:23  calle
+ * - Middleware extention now working with 2.3.49 (capifs).
+ * - Fixed typos in debug section of capi.c
+ * - Bugfix: Makefile corrected for b1pcmcia.c
+ *
+ * Revision 1.2  2000/03/06 09:17:07  calle
+ * - capifs: fileoperations now in inode (change for 2.3.49)
+ * - Config.in: Middleware extention not a tristate, uups.
+ *
+ * Revision 1.1  2000/03/03 16:48:38  calle
+ * - Added CAPI2.0 Middleware support (CONFIG_ISDN_CAPI)
+ *   It is now possible to create a connection with a CAPI2.0 applikation
+ *   and than to handle the data connection from /dev/capi/ (capifs) and also
+ *   using async or sync PPP on this connection.
+ *   The two major device number 190 and 191 are not confirmed yet,
+ *   but I want to save the code in cvs, before I go on.
+ *
+ *
+ */
+
+#include <linux/version.h>
+#include <linux/fs.h>
+#include <linux/tty.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/stat.h>
+#include <linux/param.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/kdev_t.h>
+#include <linux/kernel.h>
+#include <linux/locks.h>
+#include <linux/major.h>
+#include <linux/malloc.h>
+#include <linux/ctype.h>
+#include <asm/bitops.h>
+#include <asm/uaccess.h>
+
+MODULE_AUTHOR("Carsten Paeth <calle@calle.de>");
+
+static char *revision = "$Revision: 1.5 $";
+
+struct capifs_ncci {
+	struct inode *inode;
+	char used;
+	char type;
+	unsigned int num;
+	kdev_t kdev;
+};
+
+struct capifs_sb_info {
+	u32 magic;
+	struct super_block *next;
+	struct super_block **back;
+	int setuid;
+	int setgid;
+	uid_t   uid;
+	gid_t   gid;
+	umode_t mode;
+
+	unsigned int max_ncci;
+	struct capifs_ncci *nccis;
+};
+
+#define CAPIFS_SUPER_MAGIC (('C'<<8)|'N')
+#define CAPIFS_SBI_MAGIC   (('C'<<24)|('A'<<16)|('P'<<8)|'I')
+
+static inline struct capifs_sb_info *SBI(struct super_block *sb)
+{
+	return (struct capifs_sb_info *)(sb->u.generic_sbp);
+}
+
+/* ------------------------------------------------------------------ */
+
+static int capifs_root_readdir(struct file *,void *,filldir_t);
+static struct dentry *capifs_root_lookup(struct inode *,struct dentry *);
+static int capifs_revalidate(struct dentry *, int);
+
+static struct file_operations capifs_root_operations = {
+	read:		generic_read_dir,
+	readdir:	capifs_root_readdir,
+};
+
+struct inode_operations capifs_root_inode_operations = {
+	lookup: capifs_root_lookup,
+};
+
+struct inode_operations capifs_inode_operations;
+
+static struct dentry_operations capifs_dentry_operations = {
+	d_revalidate: capifs_revalidate,
+};
+
+/*
+ * /dev/capi/%d
+ * /dev/capi/r%d
+ */
+
+static int capifs_root_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+	struct inode * inode = filp->f_dentry->d_inode;
+	struct capifs_sb_info * sbi = SBI(filp->f_dentry->d_inode->i_sb);
+	off_t nr;
+	char numbuf[32];
+
+	nr = filp->f_pos;
+
+	switch(nr)
+	{
+	case 0:
+		if (filldir(dirent, ".", 1, nr, inode->i_ino) < 0)
+			return 0;
+		filp->f_pos = ++nr;
+		/* fall through */
+	case 1:
+		if (filldir(dirent, "..", 2, nr, inode->i_ino) < 0)
+			return 0;
+		filp->f_pos = ++nr;
+		/* fall through */
+	default:
+		while (nr < sbi->max_ncci) {
+			int n = nr - 2;
+			struct capifs_ncci *np = &sbi->nccis[n];
+			if (np->inode && np->used) {
+				char *p = numbuf;
+				if (np->type) *p++ = np->type;
+				sprintf(p, "%u", np->num);
+				if ( filldir(dirent, numbuf, strlen(numbuf), nr, nr) < 0 )
+					return 0;
+			}
+			filp->f_pos = ++nr;
+		}
+		break;
+	}
+
+	return 0;
+}
+
+/*
+ * Revalidate is called on every cache lookup.  We use it to check that
+ * the ncci really does still exist.  Never revalidate negative dentries;
+ * for simplicity (fix later?)
+ */
+static int capifs_revalidate(struct dentry * dentry, int flags)
+{
+	struct capifs_sb_info *sbi;
+
+	if ( !dentry->d_inode )
+		return 0;
+
+	sbi = SBI(dentry->d_inode->i_sb);
+
+	return ( sbi->nccis[dentry->d_inode->i_ino - 2].inode == dentry->d_inode );
+}
+
+static struct dentry *capifs_root_lookup(struct inode * dir, struct dentry * dentry)
+{
+	struct capifs_sb_info *sbi = SBI(dir->i_sb);
+	struct capifs_ncci *np;
+	unsigned int i;
+	char numbuf[32];
+	char *p, *tmp;
+	unsigned int num;
+	char type = 0;
+
+	dentry->d_inode = NULL;	/* Assume failure */
+	dentry->d_op    = &capifs_dentry_operations;
+
+	if (dentry->d_name.len >= sizeof(numbuf) )
+		return NULL;
+	strncpy(numbuf, dentry->d_name.name, dentry->d_name.len);
+	numbuf[dentry->d_name.len] = 0;
+        p = numbuf;
+	if (!isdigit(*p)) type = *p++;
+	tmp = p;
+	num = (unsigned int)simple_strtoul(p, &tmp, 10);
+	if (tmp == p || *tmp)
+		return NULL;
+
+	for (i = 0, np = sbi->nccis ; i < sbi->max_ncci; i++, np++) {
+		if (np->used && np->num == num && np->type == type)
+			break;
+	}
+
+	if ( i >= sbi->max_ncci )
+		return NULL;
+
+	dentry->d_inode = np->inode;
+	if ( dentry->d_inode )
+		dentry->d_inode->i_count++;
+	
+	d_add(dentry, dentry->d_inode);
+
+	return NULL;
+}
+
+/* ------------------------------------------------------------------ */
+
+static struct super_block *mounts = NULL;
+
+static void capifs_put_super(struct super_block *sb)
+{
+	struct capifs_sb_info *sbi = SBI(sb);
+	struct inode *inode;
+	int i;
+
+	for ( i = 0 ; i < sbi->max_ncci ; i++ ) {
+		if ( (inode = sbi->nccis[i].inode) ) {
+			if ( inode->i_count != 1 )
+				printk("capifs_put_super: badness: entry %d count %d\n",
+				       i, inode->i_count);
+			inode->i_nlink--;
+			iput(inode);
+		}
+	}
+
+	*sbi->back = sbi->next;
+	if ( sbi->next )
+		SBI(sbi->next)->back = sbi->back;
+
+	kfree(sbi->nccis);
+	kfree(sbi);
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,51)
+	MOD_DEC_USE_COUNT;
+#endif
+}
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,51)
+static int capifs_statfs(struct super_block *sb, struct statfs *buf, int bufsiz);
+static void capifs_write_inode(struct inode *inode) { };
+#else
+static int capifs_statfs(struct super_block *sb, struct statfs *buf);
+#endif
+static void capifs_read_inode(struct inode *inode);
+
+static struct super_operations capifs_sops = {
+	read_inode:	capifs_read_inode,
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,51)
+	write_inode:	capifs_write_inode,
+#endif
+	put_super:	capifs_put_super,
+	statfs:		capifs_statfs,
+};
+
+static int capifs_parse_options(char *options, struct capifs_sb_info *sbi)
+{
+	int setuid = 0;
+	int setgid = 0;
+	uid_t uid = 0;
+	gid_t gid = 0;
+	umode_t mode = 0600;
+	unsigned int maxncci = 512;
+	char *this_char, *value;
+
+	this_char = NULL;
+	if ( options )
+		this_char = strtok(options,",");
+	for ( ; this_char; this_char = strtok(NULL,",")) {
+		if ((value = strchr(this_char,'=')) != NULL)
+			*value++ = 0;
+		if (!strcmp(this_char,"uid")) {
+			if (!value || !*value)
+				return 1;
+			uid = simple_strtoul(value,&value,0);
+			if (*value)
+				return 1;
+			setuid = 1;
+		}
+		else if (!strcmp(this_char,"gid")) {
+			if (!value || !*value)
+				return 1;
+			gid = simple_strtoul(value,&value,0);
+			if (*value)
+				return 1;
+			setgid = 1;
+		}
+		else if (!strcmp(this_char,"mode")) {
+			if (!value || !*value)
+				return 1;
+			mode = simple_strtoul(value,&value,8);
+			if (*value)
+				return 1;
+		}
+		else if (!strcmp(this_char,"maxncci")) {
+			if (!value || !*value)
+				return 1;
+			maxncci = simple_strtoul(value,&value,8);
+			if (*value)
+				return 1;
+		}
+		else
+			return 1;
+	}
+	sbi->setuid   = setuid;
+	sbi->setgid   = setgid;
+	sbi->uid      = uid;
+	sbi->gid      = gid;
+	sbi->mode     = mode & ~S_IFMT;
+	sbi->max_ncci = maxncci;
+
+	return 0;
+}
+
+struct super_block *capifs_read_super(struct super_block *s, void *data,
+				      int silent)
+{
+	struct inode * root_inode;
+	struct dentry * root;
+	struct capifs_sb_info *sbi;
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,51)
+	MOD_INC_USE_COUNT;
+	lock_super(s);
+#endif
+	/* Super block already completed? */
+	if (s->s_root)
+		goto out;
+
+	sbi = (struct capifs_sb_info *) kmalloc(sizeof(struct capifs_sb_info), GFP_KERNEL);
+	if ( !sbi )
+		goto fail;
+
+	memset(sbi, 0, sizeof(struct capifs_sb_info));
+	sbi->magic  = CAPIFS_SBI_MAGIC;
+
+	if ( capifs_parse_options(data,sbi) ) {
+		kfree(sbi);
+		printk("capifs: called with bogus options\n");
+		goto fail;
+	}
+
+	sbi->nccis = kmalloc(sizeof(struct capifs_ncci) * sbi->max_ncci, GFP_KERNEL);
+	if ( !sbi->nccis ) {
+		kfree(sbi);
+		goto fail;
+	}
+	memset(sbi->nccis, 0, sizeof(struct capifs_ncci) * sbi->max_ncci);
+
+	s->u.generic_sbp = (void *) sbi;
+	s->s_blocksize = 1024;
+	s->s_blocksize_bits = 10;
+	s->s_magic = CAPIFS_SUPER_MAGIC;
+	s->s_op = &capifs_sops;
+	s->s_root = NULL;
+
+	/*
+	 * Get the root inode and dentry, but defer checking for errors.
+	 */
+	root_inode = iget(s, 1); /* inode 1 == root directory */
+	root = d_alloc_root(root_inode);
+
+	/*
+	 * Check whether somebody else completed the super block.
+	 */
+	if (s->s_root) {
+		if (root) dput(root);
+		else iput(root_inode);
+		goto out;
+	}
+
+	if (!root) {
+		printk("capifs: get root dentry failed\n");
+		/*
+	 	* iput() can block, so we clear the super block first.
+	 	*/
+		iput(root_inode);
+		kfree(sbi->nccis);
+		kfree(sbi);
+		goto fail;
+	}
+
+	/*
+	 * Check whether somebody else completed the super block.
+	 */
+	if (s->s_root)
+		goto out;
+	
+	/*
+	 * Success! Install the root dentry now to indicate completion.
+	 */
+	s->s_root = root;
+
+	sbi->next = mounts;
+	if ( sbi->next )
+		SBI(sbi->next)->back = &(sbi->next);
+	sbi->back = &mounts;
+	mounts = s;
+
+out:	/* Success ... somebody else completed the super block for us. */ 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,51)
+	unlock_super(s);
+#endif
+	return s;
+fail:
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,51)
+	unlock_super(s);
+	MOD_DEC_USE_COUNT;
+#endif
+	return NULL;
+}
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,51)
+static int capifs_statfs(struct super_block *sb, struct statfs *buf, int bufsiz)
+{
+	struct statfs tmp;
+
+	tmp.f_type = CAPIFS_SUPER_MAGIC;
+	tmp.f_bsize = 1024;
+	tmp.f_blocks = 0;
+	tmp.f_bfree = 0;
+	tmp.f_bavail = 0;
+	tmp.f_files = 0;
+	tmp.f_ffree = 0;
+	tmp.f_namelen = NAME_MAX;
+	return copy_to_user(buf, &tmp, bufsiz) ? -EFAULT : 0;
+}
+#else
+static int capifs_statfs(struct super_block *sb, struct statfs *buf)
+{
+	buf->f_type = CAPIFS_SUPER_MAGIC;
+	buf->f_bsize = 1024;
+	buf->f_blocks = 0;
+	buf->f_bfree = 0;
+	buf->f_bavail = 0;
+	buf->f_files = 0;
+	buf->f_ffree = 0;
+	buf->f_namelen = NAME_MAX;
+	return 0;
+}
+#endif
+
+static void capifs_read_inode(struct inode *inode)
+{
+	ino_t ino = inode->i_ino;
+	struct capifs_sb_info *sbi = SBI(inode->i_sb);
+
+	inode->i_op = NULL;
+	inode->i_mode = 0;
+	inode->i_nlink = 0;
+	inode->i_size = 0;
+	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+	inode->i_blocks = 0;
+	inode->i_blksize = 1024;
+	inode->i_uid = inode->i_gid = 0;
+
+	if ( ino == 1 ) {
+		inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
+		inode->i_op = &capifs_root_inode_operations;
+		inode->i_fop = &capifs_root_operations;
+		inode->i_nlink = 2;
+		return;
+	} 
+
+	/* need dummy inode operations .... */
+	inode->i_op = &capifs_inode_operations;
+
+	ino -= 2;
+	if ( ino >= sbi->max_ncci )
+		return;		/* Bogus */
+	
+	init_special_inode(inode, S_IFCHR, 0);
+
+	return;
+}
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,51)
+static struct file_system_type capifs_fs_type = {
+	"capifs",
+	0,
+	capifs_read_super,
+	NULL
+};
+#else
+static DECLARE_FSTYPE(capifs_fs_type, "capifs", capifs_read_super, 0);
+#endif
+
+void capifs_new_ncci(char type, unsigned int num, kdev_t device)
+{
+	struct super_block *sb;
+	struct capifs_sb_info *sbi;
+	struct capifs_ncci *np;
+	ino_t ino;
+
+	for ( sb = mounts ; sb ; sb = sbi->next ) {
+		sbi = SBI(sb);
+
+		for (ino = 0, np = sbi->nccis ; ino < sbi->max_ncci; ino++, np++) {
+			if (np->used == 0) {
+				np->used = 1;
+				np->type = type;
+				np->num = num;
+				np->kdev = device;
+				break;
+			}
+		}
+
+		if ((np->inode = iget(sb, ino+2)) != 0) {
+			struct inode *inode = np->inode;
+			inode->i_uid = sbi->setuid ? sbi->uid : current->fsuid;
+			inode->i_gid = sbi->setgid ? sbi->gid : current->fsgid;
+			inode->i_mode = sbi->mode | S_IFCHR;
+			inode->i_rdev = np->kdev;
+			inode->i_nlink++;
+		}
+	}
+}
+
+void capifs_free_ncci(char type, unsigned int num)
+{
+	struct super_block *sb;
+	struct capifs_sb_info *sbi;
+	struct inode *inode;
+	struct capifs_ncci *np;
+	ino_t ino;
+
+	for ( sb = mounts ; sb ; sb = sbi->next ) {
+		sbi = SBI(sb);
+
+		for (ino = 0, np = sbi->nccis ; ino < sbi->max_ncci; ino++, np++) {
+			if (!np->used || np->type != type || np->num != num)
+				continue;
+			if (np->inode) {
+				inode = np->inode;
+				np->used = 0;
+				inode->i_nlink--;
+				iput(inode);
+				break;
+			}
+		}
+	}
+}
+
+int __init capifs_init(void)
+{
+	char rev[10];
+	char *p;
+	int err;
+
+	if ((p = strchr(revision, ':'))) {
+		strcpy(rev, p + 1);
+		p = strchr(rev, '$');
+		*p = 0;
+	} else
+		strcpy(rev, "1.0");
+
+	err = register_filesystem(&capifs_fs_type);
+	if (err)
+		return err;
+#ifdef MODULE
+        printk(KERN_NOTICE "capifs: Rev%s: loaded\n", rev);
+#else
+	printk(KERN_NOTICE "capifs: Rev%s: started\n", rev);
+#endif
+	return 0;
+}
+
+void capifs_exit(void)
+{
+	unregister_filesystem(&capifs_fs_type);
+}
+
+EXPORT_SYMBOL(capifs_new_ncci);
+EXPORT_SYMBOL(capifs_free_ncci);
+
+#ifdef MODULE
+
+int init_module(void)
+{
+	return capifs_init();
+}
+
+void cleanup_module(void)
+{
+	capifs_exit();
+}
+
+#endif