Systemd/udevdb.c

/*
 * udevdb.c
 *
 * Userspace devfs
 *
 * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
 * Copyright (C) 2003 IBM Corp.
 *
 *	This program is free software; you can redistribute it and/or modify it
 *	under the terms of the GNU General Public License as published by the
 *	Free Software Foundation version 2 of the License.
 * 
 *	This program is distributed in the hope that it will be useful, but
 *	WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *	General Public License for more details.
 * 
 *	You should have received a copy of the GNU General Public License along
 *	with this program; if not, write to the Free Software Foundation, Inc.,
 *	675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

/*
 * udev database library
 */
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include <errno.h>
#include <signal.h>

#include "udev_version.h"
#include "udev.h"
#include "namedev.h"
#include "udevdb.h"
#include "tdb/tdb.h"

static TDB_CONTEXT *udevdb;

/**
 * busdb_record - bus and id are keys to look up name of device
 */
struct busdb_record {
	char name[NAME_SIZE];
};

/**
 * classdb_record - class name and class device name used as keys to find
 *	device name.
 */
struct classdb_record {
	char name[NAME_SIZE];
};

/**
 * namedb_record - device name is key, remaining udevice info stored here.
 */
struct namedb_record {
	char sysfs_path[PATH_SIZE];
	char class_dev_name[NAME_SIZE];
	char class_name[NAME_SIZE];
	char bus[BUS_SIZE];
	char id[ID_SIZE];
	char driver[NAME_SIZE];
	char type;
	int major;
	int minor;
	int mode;
};

/**
 * udevdb_close: close udev database
 */
static void udevdb_close(void)
{
	if (udevdb != NULL) {
		tdb_close(udevdb);
		udevdb = NULL;
	}
}

/**
 * udevdb_open: opens udev's database
 * @method: database can either be in memory - UDEVDB_INTERNAL - or
 * 	written to a file with UDEVDB_DEFAULT.
 */
static int udevdb_open(int method)
{
	udevdb = tdb_open(UDEV_CONFIG_DIR UDEV_DB, 0, method, O_RDWR | O_CREAT, 0644);
	if (udevdb == NULL) {
		if (method == UDEVDB_INTERNAL)
			dbg("Unable to initialize in-memory database");
		else
			dbg("Unable to initialize database at %s", UDEV_CONFIG_DIR UDEV_DB);
		return -EINVAL;
	}
	return 0;
}

/**
 * busdb_fetch
 */
static struct busdb_record *busdb_fetch(const char *bus, const char *id)
{
	TDB_DATA key, data;
	char keystr[BUS_SIZE+ID_SIZE+2]; 
	struct busdb_record *rec = NULL;

	if (bus == NULL || id == NULL)
		return NULL; 
	if (strlen(bus) >= BUS_SIZE || strlen(id) >= ID_SIZE)
		return NULL;

	memset(keystr, 0, (BUS_SIZE+ID_SIZE+2));
	strcpy(keystr, bus);
	strcat(keystr, UDEVDB_DEL);
	strcat(keystr, id);

	key.dptr = (void *)keystr;
	key.dsize = strlen(keystr) + 1;

	data = tdb_fetch(udevdb, key);
	if (data.dptr == NULL || data.dsize == 0)
		return NULL;
	
	rec = (struct busdb_record *)malloc(sizeof(struct busdb_record));
	if (rec == NULL) {
		free(data.dptr);
		return NULL;
	}
	
	memcpy(rec, data.dptr, sizeof(struct busdb_record));
	free(data.dptr);

	return rec;
}

/**
 * classdb_fetch
 */
static struct classdb_record *classdb_fetch(const char *cls, 
						const char *cls_dev)
{
	TDB_DATA key, data;
	char keystr[NAME_SIZE+NAME_SIZE+2]; 
	struct classdb_record *rec = NULL;

	if (cls == NULL || cls_dev == NULL)
		return NULL; 
	if (strlen(cls) >= NAME_SIZE || strlen(cls_dev) >= NAME_SIZE)
		return NULL;

	memset(keystr, 0, (NAME_SIZE+NAME_SIZE+2));
	strcpy(keystr, cls);
	strcat(keystr, UDEVDB_DEL);
	strcat(keystr, cls_dev);

	key.dptr = (void *)keystr;
	key.dsize = strlen(keystr) + 1;

	data = tdb_fetch(udevdb, key);
	if (data.dptr == NULL || data.dsize == 0)
		return NULL;
	
	rec = (struct classdb_record *)malloc(sizeof(struct classdb_record));
	if (rec == NULL) {
		free(data.dptr);
		return NULL;
	}
	
	memcpy(rec, data.dptr, sizeof(struct classdb_record));
	free(data.dptr);

	return rec;
}

/**
 * namedb_fetch
 */
static struct namedb_record *namedb_fetch(const char *name)
{
	TDB_DATA key, data;
	char nm_keystr[NAME_SIZE]; 
	struct namedb_record *nrec = NULL;

	if (name == NULL)
		return NULL; 
	if (strlen(name) >= NAME_SIZE)
		return NULL;

	memset(nm_keystr, 0, NAME_SIZE);
	strcpy(nm_keystr, name);

	key.dptr = (void *)nm_keystr;
	key.dsize = strlen(nm_keystr) + 1;

	data = tdb_fetch(udevdb, key);
	if (data.dptr == NULL || data.dsize == 0)
		return NULL;

	nrec = (struct namedb_record *)malloc(sizeof(struct namedb_record));
	if (nrec == NULL) {
		free(data.dptr);
		return NULL;
	}
	
	memcpy(nrec, data.dptr, sizeof(struct namedb_record));
	free(data.dptr);

	return nrec;
}

/**
 * busdb_store
 */
static int busdb_store(const struct udevice *dev)
{
	TDB_DATA key, data;
	char keystr[BUS_SIZE+ID_SIZE+2];
	struct busdb_record rec;
	int retval = 0;

	if (dev == NULL)
		return -1;

	memset(keystr, 0, (BUS_SIZE+ID_SIZE+2));
	strcpy(keystr, dev->bus_name);
	strcat(keystr, UDEVDB_DEL);
	strcat(keystr, dev->bus_id);

	key.dptr = (void *)keystr;
	key.dsize = strlen(keystr) + 1;
	
	strcpy(rec.name, dev->name);

	data.dptr = (void *) &rec;
	data.dsize = sizeof(rec);
	
	retval = tdb_store(udevdb, key, data, TDB_REPLACE); 
	return retval;
}

/**
 * classdb_store
 */
static int classdb_store(const struct udevice *dev)
{
	TDB_DATA key, data;
	char keystr[NAME_SIZE+NAME_SIZE+2];
	struct classdb_record rec;
	int retval = 0;

	if (dev == NULL)
		return -1;

	memset(keystr, 0, (NAME_SIZE+NAME_SIZE+2));
	strcpy(keystr, dev->class_name);
	strcat(keystr, UDEVDB_DEL);
	strcat(keystr, dev->class_dev_name);

	key.dptr = (void *)keystr;
	key.dsize = strlen(keystr) + 1;
	
	strcpy(rec.name, dev->name);

	data.dptr = (void *) &rec;
	data.dsize = sizeof(rec);
	
	retval = tdb_store(udevdb, key, data, TDB_REPLACE); 
	return retval;
}

/**
 * namedb_store
 */
static int namedb_store(const struct udevice *dev)
{
	TDB_DATA key, data;
	char keystr[NAME_SIZE];
	struct namedb_record rec;
	int retval = 0;

	if (dev == NULL)
		return -1;

	memset(keystr, 0, NAME_SIZE);
	strcpy(keystr, dev->name);

	key.dptr = (void *)keystr;
	key.dsize = strlen(keystr) + 1;
	
	strcpy(rec.sysfs_path, dev->sysfs_path);
	strcpy(rec.bus, dev->bus_name);
	strcpy(rec.id, dev->bus_id);
	strcpy(rec.class_dev_name, dev->class_dev_name);
	strcpy(rec.class_name, dev->class_name);
	strcpy(rec.driver, dev->driver);
	rec.type = dev->type;
	rec.major = dev->major;
	rec.minor = dev->minor;
	rec.mode = dev->mode;

	data.dptr = (void *) &rec;
	data.dsize = sizeof(rec);
	
	retval = tdb_store(udevdb, key, data, TDB_REPLACE); 
	return retval;
}

/**
 * busdb_delete
 */
static int busdb_delete(const char *bus, const char *id)
{
	TDB_DATA key;
	char keystr[BUS_SIZE+ID_SIZE+2]; 
	int retval = 0;

	if (bus == NULL || id == NULL)
		return -1; 
	if (strlen(bus) >= BUS_SIZE || strlen(id) >= ID_SIZE)
		return -1;

	memset(keystr, 0, (BUS_SIZE+ID_SIZE+2));
	strcpy(keystr, bus);
	strcat(keystr, UDEVDB_DEL);
	strcat(keystr, id);

	key.dptr = (void *)keystr;
	key.dsize = strlen(keystr) + 1;

	retval = tdb_delete(udevdb, key);
	return retval;
}

/**
 * classdb_delete
 */
static int classdb_delete(const char *cls, const char *cls_dev)
{
	TDB_DATA key;
	char keystr[NAME_SIZE+NAME_SIZE+2]; 
	int retval = 0;

	if (cls == NULL || cls_dev == NULL)
		return -1; 
	if (strlen(cls) >= NAME_SIZE || strlen(cls_dev) >= NAME_SIZE)
		return -1;

	memset(keystr, 0, (NAME_SIZE+NAME_SIZE+2));
	strcpy(keystr, cls);
	strcat(keystr, UDEVDB_DEL);
	strcat(keystr, cls_dev);

	key.dptr = (void *)keystr;
	key.dsize = strlen(keystr) + 1;

	retval = tdb_delete(udevdb, key);
	return retval;
}

/**
 * namedb_delete
 */
static int namedb_delete(const char *name)
{
	TDB_DATA key;
	char keystr[NAME_SIZE]; 
	int retval = 0;

	if (name == NULL)
		return -1; 
	if (strlen(name) >= NAME_SIZE)
		return -1;

	memset(keystr, 0, NAME_SIZE);
	strcpy(keystr, name);

	key.dptr = (void *)keystr;
	key.dsize = strlen(keystr) + 1;

	retval = tdb_delete(udevdb, key);
	return retval;
}

/**
 * udevdb_delete_udevice
 */
int udevdb_delete_udevice(const char *name)
{
	struct namedb_record *nrec = NULL;

	if (name == NULL)
		return -1; 

	nrec = namedb_fetch(name);
	if (nrec == NULL)
		return -1;

	busdb_delete(nrec->bus, nrec->id);
	classdb_delete(nrec->class_name, nrec->class_dev_name);
	namedb_delete(name);
	free(nrec);

	return 0;
}

/**
 * udevdb_add_udevice: adds udevice to database
 */
int udevdb_add_udevice(const struct udevice *dev)
{
	if (dev == NULL) 
		return -1;

	if ((busdb_store(dev)) != 0)
		return -1;
	if ((classdb_store(dev)) != 0)
		return -1;
	if ((namedb_store(dev)) != 0)
		return -1;

	return 0;
}

/**
 * udevdb_get_device: grab's device by name
 */
struct udevice *udevdb_get_udevice(const char *name)
{
	struct namedb_record *nrec = NULL;
	struct udevice *dev = NULL;

	if (name == NULL)
		return NULL; 

	nrec = namedb_fetch(name);
	if (nrec == NULL)
		return NULL;

	dev = (struct udevice *)malloc(sizeof(struct udevice));
	if (dev == NULL) {
		free(nrec);
		return NULL;
	}

	strcpy(dev->name, name);
	strcpy(dev->sysfs_path, nrec->sysfs_path);
	strcpy(dev->class_dev_name, nrec->class_dev_name);
	strcpy(dev->class_name, nrec->class_name);
	strcpy(dev->bus_name, nrec->bus);
	strcpy(dev->bus_id, nrec->id);
	dev->type = nrec->type;
	dev->major = nrec->major;
	dev->minor = nrec->minor;
	dev->mode = nrec->mode;

	free(nrec);

	return dev;
}

/**
 * udevdb_get_device_by_bus
 */
struct udevice *udevdb_get_udevice_by_bus(const char *bus, const char *id)
{
	struct busdb_record *brec = NULL;
	struct udevice *dev = NULL;

	if (bus == NULL || id == NULL)
		return NULL;

	brec = busdb_fetch(bus, id);
	if (brec == NULL)
		return NULL;

	dev = udevdb_get_udevice(brec->name);
	free(brec);

	return dev;
}

/**
 * udevdb_get_udevice_by_class
 */
struct udevice *udevdb_get_udevice_by_class(const char *cls, 
						const char *cls_dev)
{
	struct classdb_record *crec = NULL;
	struct udevice *dev = NULL;

	if (cls == NULL || cls_dev == NULL)
		return NULL;

	crec = classdb_fetch(cls, cls_dev);
	if (crec == NULL)
		return NULL;

	dev = udevdb_get_udevice(crec->name);
	free(crec);

	return dev;
}

/**
 * udevdb_exit: closes database
 */
void udevdb_exit(void)
{
	udevdb_close();
}

/**
 * udevdb_init: initializes database
 */
int udevdb_init(int init_flag)
{
	if (init_flag != UDEVDB_DEFAULT && init_flag != UDEVDB_INTERNAL)
		return -1;

	return udevdb_open(init_flag);
}