* Exim - an Internet mail transport agent *
*************************************************/
+/* Copyright (c) The Exim Maintainers 2020 - 2022 */
/* Copyright (c) University of Cambridge 1995 - 2018 */
/* See the file NOTICE for conditions of use and distribution. */
#include "exim.h"
+/* We have buffers holding path names for database files.
+PATH_MAX could be used here, but would be wasting memory, as we deal
+with database files like $spooldirectory/db/<name> */
+#define PATHLEN 256
+
/* Functions for accessing Exim's hints database, which consists of a number of
different DBM files. This module does not contain code for reading DBM files
-/*************************************************
-* Berkeley DB error callback *
-*************************************************/
-
-/* For Berkeley DB >= 2, we can define a function to be called in case of DB
-errors. This should help with debugging strange DB problems, e.g. getting "File
-exists" when you try to open a db file. The API for this function was changed
-at DB release 4.3. */
-
-#if defined(USE_DB) && defined(DB_VERSION_STRING)
-void
-#if DB_VERSION_MAJOR > 4 || (DB_VERSION_MAJOR == 4 && DB_VERSION_MINOR >= 3)
-dbfn_bdb_error_callback(const DB_ENV *dbenv, const char *pfx, const char *msg)
-{
-dbenv = dbenv;
-#else
-dbfn_bdb_error_callback(const char *pfx, char *msg)
-{
-#endif
-pfx = pfx;
-log_write(0, LOG_MAIN, "Berkeley DB error: %s", msg);
-}
-#endif
-
-
-
-
/*************************************************
* Open and lock a database file *
*************************************************/
dbblock Points to an open_db block to be filled in.
lof If TRUE, write to the log for actual open failures (locking failures
are always logged).
+ panic If TRUE, panic on failure to create the db directory
Returns: NULL if the open failed, or the locking failed. After locking
failures, errno is zero.
*/
open_db *
-dbfn_open(uschar *name, int flags, open_db *dbblock, BOOL lof)
+dbfn_open(uschar *name, int flags, open_db *dbblock, BOOL lof, BOOL panic)
{
int rc, save_errno;
BOOL read_only = flags == O_RDONLY;
-BOOL created = FALSE;
flock_t lock_data;
-uschar dirname[256], filename[256];
+uschar dirname[PATHLEN], filename[PATHLEN];
DEBUG(D_hints_lookup) acl_level++;
snprintf(CS dirname, sizeof(dirname), "%s/db", spool_directory);
snprintf(CS filename, sizeof(filename), "%s/%s.lockfile", dirname, name);
+priv_drop_temp(exim_uid, exim_gid);
if ((dbblock->lockfd = Uopen(filename, O_RDWR, EXIMDB_LOCKFILE_MODE)) < 0)
{
- created = TRUE;
- (void)directory_make(spool_directory, US"db", EXIMDB_DIRECTORY_MODE, TRUE);
+ (void)directory_make(spool_directory, US"db", EXIMDB_DIRECTORY_MODE, panic);
dbblock->lockfd = Uopen(filename, O_RDWR|O_CREAT, EXIMDB_LOCKFILE_MODE);
}
+priv_restore();
if (dbblock->lockfd < 0)
{
log_write(0, LOG_MAIN, "%s",
- string_open_failed(errno, "database lock file %s", filename));
+ string_open_failed("database lock file %s", filename));
errno = 0; /* Indicates locking failure */
DEBUG(D_hints_lookup) acl_level--;
return NULL;
open call. */
snprintf(CS filename, sizeof(filename), "%s/%s", dirname, name);
-EXIM_DBOPEN(filename, dirname, flags, EXIMDB_MODE, &(dbblock->dbptr));
+priv_drop_temp(exim_uid, exim_gid);
+dbblock->dbptr = exim_dbopen(filename, dirname, flags, EXIMDB_MODE);
if (!dbblock->dbptr && errno == ENOENT && flags == O_RDWR)
{
DEBUG(D_hints_lookup)
debug_printf_indent("%s appears not to exist: trying to create\n", filename);
- created = TRUE;
- EXIM_DBOPEN(filename, dirname, flags|O_CREAT, EXIMDB_MODE, &(dbblock->dbptr));
+ dbblock->dbptr = exim_dbopen(filename, dirname, flags|O_CREAT, EXIMDB_MODE);
}
-
save_errno = errno;
-
-/* If we are running as root and this is the first access to the database, its
-files will be owned by root. We want them to be owned by exim. We detect this
-situation by noting above when we had to create the lock file or the database
-itself. Because the different dbm libraries use different extensions for their
-files, I don't know of any easier way of arranging this than scanning the
-directory for files with the appropriate base name. At least this deals with
-the lock file at the same time. Also, the directory will typically have only
-half a dozen files, so the scan will be quick.
-
-This code is placed here, before the test for successful opening, because there
-was a case when a file was created, but the DBM library still returned NULL
-because of some problem. It also sorts out the lock file if that was created
-but creation of the database file failed. */
-
-if (created && geteuid() == root_uid)
- {
- DIR *dd;
- struct dirent *ent;
- uschar *lastname = Ustrrchr(filename, '/') + 1;
- int namelen = Ustrlen(name);
-
- *lastname = 0;
- dd = opendir(CS filename);
-
- while ((ent = readdir(dd)))
- if (Ustrncmp(ent->d_name, name, namelen) == 0)
- {
- struct stat statbuf;
- Ustrcpy(lastname, ent->d_name);
- if (Ustat(filename, &statbuf) >= 0 && statbuf.st_uid != exim_uid)
- {
- DEBUG(D_hints_lookup) debug_printf_indent("ensuring %s is owned by exim\n", filename);
- if (exim_chown(filename, exim_uid, exim_gid))
- DEBUG(D_hints_lookup) debug_printf_indent("failed setting %s to owned by exim\n", filename);
- }
- }
-
- closedir(dd);
- }
+priv_restore();
/* If the open has failed, return NULL, leaving errno set. If lof is TRUE,
log the event - also for debugging - but debug only if the file just doesn't
if (!dbblock->dbptr)
{
+ errno = save_errno;
if (lof && save_errno != ENOENT)
- log_write(0, LOG_MAIN, "%s", string_open_failed(save_errno, "DB file %s",
+ log_write(0, LOG_MAIN, "%s", string_open_failed("DB file %s",
filename));
else
DEBUG(D_hints_lookup)
- debug_printf_indent("%s\n", CS string_open_failed(save_errno, "DB file %s",
+ debug_printf_indent("%s\n", CS string_open_failed("DB file %s",
filename));
(void)close(dbblock->lockfd);
errno = save_errno;
void
dbfn_close(open_db *dbblock)
{
-EXIM_DBCLOSE(dbblock->dbptr);
+exim_dbclose(dbblock->dbptr);
(void)close(dbblock->lockfd);
DEBUG(D_hints_lookup)
{ debug_printf_indent("closed hints database and lockfile\n"); acl_level--; }
void *yield;
EXIM_DATUM key_datum, result_datum;
int klen = Ustrlen(key) + 1;
-uschar * key_copy = store_get(klen);
+uschar * key_copy = store_get(klen, key);
memcpy(key_copy, key, klen);
DEBUG(D_hints_lookup) debug_printf_indent("dbfn_read: key=%s\n", key);
-EXIM_DATUM_INIT(key_datum); /* Some DBM libraries require the datum */
-EXIM_DATUM_INIT(result_datum); /* to be cleared before use. */
-EXIM_DATUM_DATA(key_datum) = CS key_copy;
-EXIM_DATUM_SIZE(key_datum) = klen;
+exim_datum_init(&key_datum); /* Some DBM libraries require the datum */
+exim_datum_init(&result_datum); /* to be cleared before use. */
+exim_datum_data_set(&key_datum, key_copy);
+exim_datum_size_set(&key_datum, klen);
+
+if (!exim_dbget(dbblock->dbptr, &key_datum, &result_datum)) return NULL;
-if (!EXIM_DBGET(dbblock->dbptr, key_datum, result_datum)) return NULL;
+/* Assume the data store could have been tainted. Properly, we should
+store the taint status with the data. */
-yield = store_get(EXIM_DATUM_SIZE(result_datum));
-memcpy(yield, EXIM_DATUM_DATA(result_datum), EXIM_DATUM_SIZE(result_datum));
-if (length != NULL) *length = EXIM_DATUM_SIZE(result_datum);
+yield = store_get(exim_datum_size_get(&result_datum), GET_TAINTED);
+memcpy(yield, exim_datum_data_get(&result_datum), exim_datum_size_get(&result_datum));
+if (length) *length = exim_datum_size_get(&result_datum);
-EXIM_DATUM_FREE(result_datum); /* Some DBM libs require freeing */
+exim_datum_free(&result_datum); /* Some DBM libs require freeing */
return yield;
}
+/* Read a record. If the length is not as expected then delete it, write
+an error log line, delete the record and return NULL.
+Use this for fixed-size records (so not retry or wait records).
+
+Arguments:
+ dbblock a pointer to an open database block
+ key the key of the record to be read
+ length the expected record length
+
+Returns: a pointer to the retrieved record, or
+ NULL if the record is not found/bad
+*/
+
+void *
+dbfn_read_enforce_length(open_db * dbblock, const uschar * key, size_t length)
+{
+int rlen;
+void * yield = dbfn_read_with_length(dbblock, key, &rlen);
+
+if (yield)
+ {
+ if (rlen == length) return yield;
+ log_write(0, LOG_MAIN|LOG_PANIC, "Bad db record size for '%s'", key);
+ dbfn_delete(dbblock, key);
+ }
+return NULL;
+}
+
/*************************************************
* Write to database file *
EXIM_DATUM key_datum, value_datum;
dbdata_generic *gptr = (dbdata_generic *)ptr;
int klen = Ustrlen(key) + 1;
-uschar * key_copy = store_get(klen);
+uschar * key_copy = store_get(klen, key);
memcpy(key_copy, key, klen);
gptr->time_stamp = time(NULL);
DEBUG(D_hints_lookup) debug_printf_indent("dbfn_write: key=%s\n", key);
-EXIM_DATUM_INIT(key_datum); /* Some DBM libraries require the datum */
-EXIM_DATUM_INIT(value_datum); /* to be cleared before use. */
-EXIM_DATUM_DATA(key_datum) = CS key_copy;
-EXIM_DATUM_SIZE(key_datum) = klen;
-EXIM_DATUM_DATA(value_datum) = CS ptr;
-EXIM_DATUM_SIZE(value_datum) = length;
-return EXIM_DBPUT(dbblock->dbptr, key_datum, value_datum);
+exim_datum_init(&key_datum); /* Some DBM libraries require the datum */
+exim_datum_init(&value_datum); /* to be cleared before use. */
+exim_datum_data_set(&key_datum, key_copy);
+exim_datum_size_set(&key_datum, klen);
+exim_datum_data_set(&value_datum, ptr);
+exim_datum_size_set(&value_datum, length);
+return exim_dbput(dbblock->dbptr, &key_datum, &value_datum);
}
dbfn_delete(open_db *dbblock, const uschar *key)
{
int klen = Ustrlen(key) + 1;
-uschar * key_copy = store_get(klen);
+uschar * key_copy = store_get(klen, key);
+EXIM_DATUM key_datum;
DEBUG(D_hints_lookup) debug_printf_indent("dbfn_delete: key=%s\n", key);
memcpy(key_copy, key, klen);
-EXIM_DATUM key_datum;
-EXIM_DATUM_INIT(key_datum); /* Some DBM libraries require clearing */
-EXIM_DATUM_DATA(key_datum) = CS key_copy;
-EXIM_DATUM_SIZE(key_datum) = klen;
-return EXIM_DBDEL(dbblock->dbptr, key_datum);
+exim_datum_init(&key_datum); /* Some DBM libraries require clearing */
+exim_datum_data_set(&key_datum, key_copy);
+exim_datum_size_set(&key_datum, klen);
+return exim_dbdel(dbblock->dbptr, &key_datum);
}
{
EXIM_DATUM key_datum, value_datum;
uschar *yield;
-value_datum = value_datum; /* dummy; not all db libraries use this */
DEBUG(D_hints_lookup) debug_printf_indent("dbfn_scan\n");
/* Some dbm require an initialization */
-if (start) EXIM_DBCREATE_CURSOR(dbblock->dbptr, cursor);
+if (start) *cursor = exim_dbcreate_cursor(dbblock->dbptr);
-EXIM_DATUM_INIT(key_datum); /* Some DBM libraries require the datum */
-EXIM_DATUM_INIT(value_datum); /* to be cleared before use. */
+exim_datum_init(&key_datum); /* Some DBM libraries require the datum */
+exim_datum_init(&value_datum); /* to be cleared before use. */
-yield = (EXIM_DBSCAN(dbblock->dbptr, key_datum, value_datum, start, *cursor))?
- US EXIM_DATUM_DATA(key_datum) : NULL;
+yield = exim_dbscan(dbblock->dbptr, &key_datum, &value_datum, start, *cursor)
+ ? US exim_datum_data_get(&key_datum) : NULL;
/* Some dbm require a termination */
-if (!yield) EXIM_DBDELETE_CURSOR(*cursor);
+if (!yield) exim_dbdelete_cursor(*cursor);
return yield;
}
}
start = clock();
- odb = dbfn_open(s, O_RDWR, dbblock + i, TRUE);
+ odb = dbfn_open(s, O_RDWR, dbblock + i, TRUE, TRUE);
stop = clock();
if (odb)
git://git.exim.org / exim.git / blobdiff