xref: /illumos-gate/usr/src/cmd/dlmgmtd/dlmgmt_db.c (revision 6a634c9d)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <syslog.h>
#include <zone.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stropts.h>
#include <sys/conf.h>
#include <pthread.h>
#include <unistd.h>
#include <wait.h>
#include <libcontract.h>
#include <libcontract_priv.h>
#include <sys/contract/process.h>
#include "dlmgmt_impl.h"

typedef enum dlmgmt_db_op {
	DLMGMT_DB_OP_WRITE,
	DLMGMT_DB_OP_DELETE,
	DLMGMT_DB_OP_READ
} dlmgmt_db_op_t;

typedef struct dlmgmt_db_req_s {
	struct dlmgmt_db_req_s	*ls_next;
	dlmgmt_db_op_t		ls_op;
	char			ls_link[MAXLINKNAMELEN];
	datalink_id_t		ls_linkid;
	zoneid_t		ls_zoneid;
	uint32_t		ls_flags;	/* Either DLMGMT_ACTIVE or   */
						/* DLMGMT_PERSIST, not both. */
} dlmgmt_db_req_t;

/*
 * List of pending db updates (e.g., because of a read-only filesystem).
 */
static dlmgmt_db_req_t	*dlmgmt_db_req_head = NULL;
static dlmgmt_db_req_t	*dlmgmt_db_req_tail = NULL;

/*
 * rewrite_needed is set to B_TRUE by process_link_line() if it encounters a
 * line with an old format.  This will cause the file being read to be
 * re-written with the current format.
 */
static boolean_t	rewrite_needed;

static int		dlmgmt_db_update(dlmgmt_db_op_t, const char *,
			    dlmgmt_link_t *, uint32_t);
static int		dlmgmt_process_db_req(dlmgmt_db_req_t *);
static int		dlmgmt_process_db_onereq(dlmgmt_db_req_t *, boolean_t);
static void		*dlmgmt_db_update_thread(void *);
static boolean_t	process_link_line(char *, dlmgmt_link_t *);
static int		process_db_write(dlmgmt_db_req_t *, FILE *, FILE *);
static int		process_db_read(dlmgmt_db_req_t *, FILE *);
static void		generate_link_line(dlmgmt_link_t *, boolean_t, char *);

#define	BUFLEN(lim, ptr)	(((lim) > (ptr)) ? ((lim) - (ptr)) : 0)
#define	MAXLINELEN		1024

typedef void db_walk_func_t(dlmgmt_link_t *);

/*
 * Translator functions to go from dladm_datatype_t to character strings.
 * Each function takes a pointer to a buffer, the size of the buffer,
 * the name of the attribute, and the value to be written.  The functions
 * return the number of bytes written to the buffer.  If the buffer is not big
 * enough to hold the string representing the value, then nothing is written
 * and 0 is returned.
 */
typedef size_t write_func_t(char *, size_t, char *, void *);

/*
 * Translator functions to read from a NULL terminated string buffer into
 * something of the given DLADM_TYPE_*.  The functions each return the number
 * of bytes read from the string buffer.  If there is an error reading data
 * from the buffer, then 0 is returned.  It is the caller's responsibility
 * to free the data allocated by these functions.
 */
typedef size_t read_func_t(char *, void **);

typedef struct translator_s {
	const char	*type_name;
	write_func_t	*write_func;
	read_func_t	*read_func;
} translator_t;

/*
 * Translator functions, defined later but declared here so that
 * the translator table can be defined.
 */
static write_func_t	write_str, write_boolean, write_uint64;
static read_func_t	read_str, read_boolean, read_int64;

/*
 * Translator table, indexed by dladm_datatype_t.
 */
static translator_t translators[] = {
	{ "string",	write_str,	read_str	},
	{ "boolean",	write_boolean,	read_boolean	},
	{ "int",	write_uint64,	read_int64	}
};

static size_t ntranslators = sizeof (translators) / sizeof (translator_t);

#define	LINK_PROPERTY_DELIMINATOR	";"
#define	LINK_PROPERTY_TYPE_VALUE_SEP	","
#define	BASE_PROPERTY_LENGTH(t, n) (strlen(translators[(t)].type_name) +\
				    strlen(LINK_PROPERTY_TYPE_VALUE_SEP) +\
				    strlen(LINK_PROPERTY_DELIMINATOR) +\
				    strlen((n)))
#define	GENERATE_PROPERTY_STRING(buf, length, conv, name, type, val) \
	    (snprintf((buf), (length), "%s=%s%s" conv "%s", (name), \
	    translators[(type)].type_name, \
	    LINK_PROPERTY_TYPE_VALUE_SEP, (val), LINK_PROPERTY_DELIMINATOR))

/*
 * Name of the cache file to keep the active <link name, linkid> mapping
 */
char	cachefile[MAXPATHLEN];

#define	DLMGMT_PERSISTENT_DB_PATH	"/etc/dladm/datalink.conf"
#define	DLMGMT_MAKE_FILE_DB_PATH(buffer, persistent)	\
	(void) snprintf((buffer), MAXPATHLEN, "%s", \
	(persistent) ? DLMGMT_PERSISTENT_DB_PATH : cachefile);

typedef struct zopen_arg {
	const char	*zopen_modestr;
	int		*zopen_pipe;
	int		zopen_fd;
} zopen_arg_t;

typedef struct zrename_arg {
	const char	*zrename_newname;
} zrename_arg_t;

typedef union zfoparg {
	zopen_arg_t	zfop_openarg;
	zrename_arg_t	zfop_renamearg;
} zfoparg_t;

typedef struct zfcbarg {
	boolean_t	zfarg_inglobalzone; /* is callback in global zone? */
	zoneid_t	zfarg_finglobalzone; /* is file in global zone? */
	const char	*zfarg_filename;
	zfoparg_t	*zfarg_oparg;
} zfarg_t;
#define	zfarg_openarg	zfarg_oparg->zfop_openarg
#define	zfarg_renamearg	zfarg_oparg->zfop_renamearg

/* zone file callback */
typedef int zfcb_t(zfarg_t *);

/*
 * Execute an operation on filename relative to zoneid's zone root.  If the
 * file is in the global zone, then the zfcb() callback will simply be called
 * directly.  If the file is in a non-global zone, then zfcb() will be called
 * both from the global zone's context, and from the non-global zone's context
 * (from a fork()'ed child that has entered the non-global zone).  This is
 * done to allow the callback to communicate with itself if needed (e.g. to
 * pass back the file descriptor of an opened file).
 */
static int
dlmgmt_zfop(const char *filename, zoneid_t zoneid, zfcb_t *zfcb,
    zfoparg_t *zfoparg)
{
	int		ctfd;
	int		err;
	pid_t		childpid;