OpenSolaris_b135/cmd/sendmail/libsmdb/smdb.c
/*
** Copyright (c) 1999-2002 Sendmail, Inc. and its suppliers.
** All rights reserved.
**
** By using this file, you agree to the terms and conditions set
** forth in the LICENSE file which can be found at the top level of
** the sendmail distribution.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sm/gen.h>
SM_RCSID("@(#)$Id: smdb.c,v 8.58 2004/08/03 20:58:38 ca Exp $")
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <sendmail/sendmail.h>
#include <libsmdb/smdb.h>
static bool smdb_lockfile __P((int, int));
/*
** SMDB_MALLOC_DATABASE -- Allocates a database structure.
**
** Parameters:
** None
**
** Returns:
** An pointer to an allocated SMDB_DATABASE structure or
** NULL if it couldn't allocate the memory.
*/
SMDB_DATABASE *
smdb_malloc_database()
{
SMDB_DATABASE *db;
db = (SMDB_DATABASE *) malloc(sizeof(SMDB_DATABASE));
if (db != NULL)
(void) memset(db, '\0', sizeof(SMDB_DATABASE));
return db;
}
/*
** SMDB_FREE_DATABASE -- Unallocates a database structure.
**
** Parameters:
** database -- a SMDB_DATABASE pointer to deallocate.
**
** Returns:
** None
*/
void
smdb_free_database(database)
SMDB_DATABASE *database;
{
if (database != NULL)
free(database);
}
/*
** SMDB_LOCKFILE -- lock a file using flock or (shudder) fcntl locking
**
** Parameters:
** fd -- the file descriptor of the file.
** type -- type of the lock. Bits can be:
** LOCK_EX -- exclusive lock.
** LOCK_NB -- non-blocking.
**
** Returns:
** true if the lock was acquired.
** false otherwise.
*/
static bool
smdb_lockfile(fd, type)
int fd;
int type;
{
int i;
int save_errno;
#if !HASFLOCK
int action;
struct flock lfd;
(void) memset(&lfd, '\0', sizeof lfd);
if (bitset(LOCK_UN, type))
lfd.l_type = F_UNLCK;
else if (bitset(LOCK_EX, type))
lfd.l_type = F_WRLCK;
else
lfd.l_type = F_RDLCK;
if (bitset(LOCK_NB, type))
action = F_SETLK;
else
action = F_SETLKW;
while ((i = fcntl(fd, action, &lfd)) < 0 && errno == EINTR)
continue;
if (i >= 0)
return true;
save_errno = errno;
/*
** On SunOS, if you are testing using -oQ/tmp/mqueue or
** -oA/tmp/aliases or anything like that, and /tmp is mounted
** as type "tmp" (that is, served from swap space), the
** previous fcntl will fail with "Invalid argument" errors.
** Since this is fairly common during testing, we will assume
** that this indicates that the lock is successfully grabbed.
*/
if (save_errno == EINVAL)
return true;
if (!bitset(LOCK_NB, type) ||
(save_errno != EACCES && save_errno != EAGAIN))
{
# if 0
int omode = fcntl(fd, F_GETFL, NULL);
int euid = (int) geteuid();
syslog(LOG_ERR, "cannot lockf(%s%s, fd=%d, type=%o, omode=%o, euid=%d)",
filename, ext, fd, type, omode, euid);
# endif /* 0 */
errno = save_errno;
return false;
}
#else /* !HASFLOCK */
while ((i = flock(fd, type)) < 0 && errno == EINTR)
continue;
if (i >= 0)
return true;
save_errno = errno;
if (!bitset(LOCK_NB, type) || save_errno != EWOULDBLOCK)
{
# if 0
int omode = fcntl(fd, F_GETFL, NULL);
int euid = (int) geteuid();
syslog(LOG_ERR, "cannot flock(%s%s, fd=%d, type=%o, omode=%o, euid=%d)",
filename, ext, fd, type, omode, euid);
# endif /* 0 */
errno = save_errno;
return false;
}
#endif /* !HASFLOCK */
errno = save_errno;
return false;
}
/*
** SMDB_OPEN_DATABASE -- Opens a database.
**
** This opens a database. If type is SMDB_DEFAULT it tries to
** use a DB1 or DB2 hash. If that isn't available, it will try
** to use NDBM. If a specific type is given it will try to open
** a database of that type.
**
** Parameters:
** database -- An pointer to a SMDB_DATABASE pointer where the
** opened database will be stored. This should
** be unallocated.
** db_name -- The name of the database to open. Do not include
** the file name extension.
** mode -- The mode to set on the database file or files.
** mode_mask -- Mode bits that must match on an opened database.
** sff -- Flags to safefile.
** type -- The type of database to open. Supported types
** vary depending on what was compiled in.
** user_info -- Information on the user to use for file
** permissions.
** params -- Params specific to the database being opened.
** Only supports some DB hash options right now
** (see smdb_db_open() for details).
**
** Returns:
** SMDBE_OK -- Success.
** Anything else is an error. Look up more info about the
** error in the comments for the specific open() used.
*/
int
smdb_open_database(database, db_name, mode, mode_mask, sff, type, user_info,
params)
SMDB_DATABASE **database;
char *db_name;
int mode;
int mode_mask;
long sff;
SMDB_DBTYPE type;
SMDB_USER_INFO *user_info;
SMDB_DBPARAMS *params;
{
bool type_was_default = false;
if (type == SMDB_TYPE_DEFAULT)
{
type_was_default = true;
#ifdef NEWDB
type = SMDB_TYPE_HASH;
#else /* NEWDB */
# ifdef NDBM
type = SMDB_TYPE_NDBM;
# endif /* NDBM */
#endif /* NEWDB */
}
if (type == SMDB_TYPE_DEFAULT)
return SMDBE_UNKNOWN_DB_TYPE;
if ((strncmp(type, SMDB_TYPE_HASH, SMDB_TYPE_HASH_LEN) == 0) ||
(strncmp(type, SMDB_TYPE_BTREE, SMDB_TYPE_BTREE_LEN) == 0))
{
#ifdef NEWDB
int result;
result = smdb_db_open(database, db_name, mode, mode_mask, sff,
type, user_info, params);
# ifdef NDBM
if (result == ENOENT && type_was_default)
type = SMDB_TYPE_NDBM;
else
# endif /* NDBM */
return result;
#else /* NEWDB */
return SMDBE_UNSUPPORTED_DB_TYPE;
#endif /* NEWDB */
}
if (strncmp(type, SMDB_TYPE_NDBM, SMDB_TYPE_NDBM_LEN) == 0)
{
#ifdef NDBM
int result;
result = smdb_ndbm_open(database, db_name, mode, mode_mask,
sff, type, user_info, params);
return result;
#else /* NDBM */
return SMDBE_UNSUPPORTED_DB_TYPE;
#endif /* NDBM */
}
return SMDBE_UNKNOWN_DB_TYPE;
}
/*
** SMDB_ADD_EXTENSION -- Adds an extension to a file name.
**
** Just adds a . followed by a string to a db_name if there
** is room and the db_name does not already have that extension.
**
** Parameters:
** full_name -- The final file name.
** max_full_name_len -- The max length for full_name.
** db_name -- The name of the db.
** extension -- The extension to add.
**
** Returns:
** SMDBE_OK -- Success.
** Anything else is an error. Look up more info about the
** error in the comments for the specific open() used.
*/
int
smdb_add_extension(full_name, max_full_name_len, db_name, extension)
char *full_name;
int max_full_name_len;
char *db_name;
char *extension;
{
int extension_len;
int db_name_len;
if (full_name == NULL || db_name == NULL || extension == NULL)
return SMDBE_INVALID_PARAMETER;
extension_len = strlen(extension);
db_name_len = strlen(db_name);
if (extension_len + db_name_len + 2 > max_full_name_len)
return SMDBE_DB_NAME_TOO_LONG;
if (db_name_len < extension_len + 1 ||
db_name[db_name_len - extension_len - 1] != '.' ||
strcmp(&db_name[db_name_len - extension_len], extension) != 0)
(void) sm_snprintf(full_name, max_full_name_len, "%s.%s",
db_name, extension);
else
(void) sm_strlcpy(full_name, db_name, max_full_name_len);
return SMDBE_OK;
}
/*
** SMDB_LOCK_FILE -- Locks the database file.
**
** Locks the actual database file.
**
** Parameters:
** lock_fd -- The resulting descriptor for the locked file.
** db_name -- The name of the database without extension.
** mode -- The open mode.
** sff -- Flags to safefile.
** extension -- The extension for the file.
**
** Returns:
** SMDBE_OK -- Success, otherwise errno.
*/
int
smdb_lock_file(lock_fd, db_name, mode, sff, extension)
int *lock_fd;
char *db_name;
int mode;
long sff;
char *extension;
{
int result;
char file_name[MAXPATHLEN];
result = smdb_add_extension(file_name, sizeof file_name, db_name,
extension);
if (result != SMDBE_OK)
return result;
*lock_fd = safeopen(file_name, mode & ~O_TRUNC, DBMMODE, sff);
if (*lock_fd < 0)
return errno;
return SMDBE_OK;
}
/*
** SMDB_UNLOCK_FILE -- Unlocks a file
**
** Unlocks a file.
**
** Parameters:
** lock_fd -- The descriptor for the locked file.
**
** Returns:
** SMDBE_OK -- Success, otherwise errno.
*/
int
smdb_unlock_file(lock_fd)
int lock_fd;
{
int result;
result = close(lock_fd);
if (result != 0)
return errno;
return SMDBE_OK;
}
/*
** SMDB_LOCK_MAP -- Locks a database.
**
** Parameters:
** database -- database description.
** type -- type of the lock. Bits can be:
** LOCK_EX -- exclusive lock.
** LOCK_NB -- non-blocking.
**
** Returns:
** SMDBE_OK -- Success, otherwise errno.
*/
int
smdb_lock_map(database, type)
SMDB_DATABASE *database;
int type;
{
int fd;
fd = database->smdb_lockfd(database);
if (fd < 0)
return SMDBE_NOT_FOUND;
if (!smdb_lockfile(fd, type))
return SMDBE_LOCK_NOT_GRANTED;
return SMDBE_OK;
}
/*
** SMDB_UNLOCK_MAP -- Unlocks a database
**
** Parameters:
** database -- database description.
**
** Returns:
** SMDBE_OK -- Success, otherwise errno.
*/
int
smdb_unlock_map(database)
SMDB_DATABASE *database;
{
int fd;
fd = database->smdb_lockfd(database);
if (fd < 0)
return SMDBE_NOT_FOUND;
if (!smdb_lockfile(fd, LOCK_UN))
return SMDBE_LOCK_NOT_HELD;
return SMDBE_OK;
}
/*
** SMDB_SETUP_FILE -- Gets db file ready for use.
**
** Makes sure permissions on file are safe and creates it if it
** doesn't exist.
**
** Parameters:
** db_name -- The name of the database without extension.
** extension -- The extension.
** sff -- Flags to safefile.
** mode_mask -- Mode bits that must match.
** user_info -- Information on the user to use for file
** permissions.
** stat_info -- A place to put the stat info for the file.
** Returns:
** SMDBE_OK -- Success, otherwise errno.
*/
int
smdb_setup_file(db_name, extension, mode_mask, sff, user_info, stat_info)
char *db_name;
char *extension;
int mode_mask;
long sff;
SMDB_USER_INFO *user_info;
struct stat *stat_info;
{
int st;
int result;
char db_file_name[MAXPATHLEN];
result = smdb_add_extension(db_file_name, sizeof db_file_name, db_name,
extension);
if (result != SMDBE_OK)
return result;
st = safefile(db_file_name, user_info->smdbu_id,
user_info->smdbu_group_id, user_info->smdbu_name,
sff, mode_mask, stat_info);
if (st != 0)
return st;
return SMDBE_OK;
}
/*
** SMDB_FILECHANGED -- Checks to see if a file changed.
**
** Compares the passed in stat_info with a current stat on
** the passed in file descriptor. Check filechanged for
** return values.
**
** Parameters:
** db_name -- The name of the database without extension.
** extension -- The extension.
** db_fd -- A file descriptor for the database file.
** stat_info -- An old stat_info.
** Returns:
** SMDBE_OK -- Success, otherwise errno.
*/
int
smdb_filechanged(db_name, extension, db_fd, stat_info)
char *db_name;
char *extension;
int db_fd;
struct stat *stat_info;
{
int result;
char db_file_name[MAXPATHLEN];
result = smdb_add_extension(db_file_name, sizeof db_file_name, db_name,
extension);
if (result != SMDBE_OK)
return result;
return filechanged(db_file_name, db_fd, stat_info);
}
/*
** SMDB_PRINT_AVAILABLE_TYPES -- Prints the names of the available types.
**
** Parameters:
** None
**
** Returns:
** None
*/
void
smdb_print_available_types()
{
#ifdef NDBM
printf("dbm\n");
#endif /* NDBM */
#ifdef NEWDB
printf("hash\n");
printf("btree\n");
#endif /* NEWDB */
}
/*
** SMDB_DB_DEFINITION -- Given a database type, return database definition
**
** Reads though a structure making an association with the database
** type and the required cpp define from sendmail/README.
** List size is dynamic and must be NULL terminated.
**
** Parameters:
** type -- The name of the database type.
**
** Returns:
** definition for type, otherwise NULL.
*/
typedef struct
{
SMDB_DBTYPE type;
char *dbdef;
} dbtype;
static dbtype DatabaseDefs[] =
{
{ SMDB_TYPE_HASH, "NEWDB" },
{ SMDB_TYPE_BTREE, "NEWDB" },
{ SMDB_TYPE_NDBM, "NDBM" },
{ NULL, "OOPS" }
};
char *
smdb_db_definition(type)
SMDB_DBTYPE type;
{
dbtype *ptr = DatabaseDefs;
while (ptr != NULL && ptr->type != NULL)
{
if (strcmp(type, ptr->type) == 0)
return ptr->dbdef;
ptr++;
}
return NULL;
}