Hintsbd: fix locking

[exim.git] / src / src / exim_dbutil.c

diff --git a/src/src/exim_dbutil.c b/src/src/exim_dbutil.c
index 4d213773bf9203ac9b8554bbb3e8414193a37c8d..c466ae380dc7bfdbab63741bfbbab8f849548329 100644 (file)
--- a/src/src/exim_dbutil.c
+++ b/src/src/exim_dbutil.c
@@ -2,7 +2,7 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) The Exim Maintainers 2020 - 2023 */
+/* Copyright (c) The Exim Maintainers 2020 - 2024 */
 /* Copyright (c) University of Cambridge 1995 - 2018 */
 /* See the file NOTICE for conditions of use and distribution. */
 /* SPDX-License-Identifier: GPL-2.0-or-later */
@@ -287,28 +287,26 @@ Returns:   NULL if the open failed, or the locking failed.
 */
 
 open_db *
-dbfn_open(uschar *name, int flags, open_db *dbblock, BOOL lof, BOOL panic)
+dbfn_open(const uschar * name, int flags, open_db * dbblock,
+  BOOL lof, BOOL panic)
 {
 int rc;
 struct flock lock_data;
-BOOL read_only = flags == O_RDONLY;
+BOOL read_only = (flags & (O_WRONLY|O_RDWR)) == O_RDONLY;
 uschar * dirname, * filename;
 
 /* The first thing to do is to open a separate file on which to lock. This
 ensures that Exim has exclusive use of the database before it even tries to
-open it. If there is a database, there should be a lock file in existence. */
+open it. If there is a database, there should be a lock file in existence;
+if no lockfile we infer there is no database and error out.  We open the
+lockfile using the r/w mode requested for the DB, users lacking permission
+for the DB access mode will error out here. */
 
-#ifdef COMPILE_UTILITY
 if (  asprintf(CSS &dirname, "%s/db", spool_directory) < 0
    || asprintf(CSS &filename, "%s/%s.lockfile", dirname, name) < 0)
   return NULL;
-#else
-dirname = string_sprintf("%s/db", spool_directory);
-filename = string_sprintf("%s/%s.lockfile", dirname, name);
-#endif
 
-dbblock->lockfd = Uopen(filename, flags, 0);
-if (dbblock->lockfd < 0)
+if ((dbblock->lockfd = Uopen(filename, flags, 0)) < 0)
   {
   printf("** Failed to open database lock file %s: %s\n", filename,
     strerror(errno));
@@ -331,7 +329,7 @@ if (sigalrm_seen) errno = ETIMEDOUT;
 if (rc < 0)
   {
   printf("** Failed to get %s lock for %s: %s",
-    flags & O_WRONLY ? "write" : "read",
+    read_only ? "read" : "write",
     filename,
     errno == ETIMEDOUT ? "timed out" : strerror(errno));
   (void)close(dbblock->lockfd);
@@ -341,14 +339,11 @@ if (rc < 0)
 /* At this point we have an opened and locked separate lock file, that is,
 exclusive access to the database, so we can go ahead and open it. */
 
-#ifdef COMPILE_UTILITY
 if (asprintf(CSS &filename, "%s/%s", dirname, name) < 0) return NULL;
-#else
-filename = string_sprintf("%s/%s", dirname, name);
-#endif
-dbblock->dbptr = exim_dbopen(filename, dirname, flags, 0);
 
-if (!dbblock->dbptr)
+if (flags & O_RDWR) flags |= O_CREAT;
+
+if (!(dbblock->dbptr = exim_dbopen(filename, dirname, flags, 0)))
   {
   printf("** Failed to open DBM file %s for %s:\n   %s%s\n", filename,
     read_only? "reading" : "writing", strerror(errno),
@@ -520,7 +515,7 @@ Arguments:
   cursor   a pointer to a pointer to a cursor anchor, for those dbm libraries
            that use the notion of a cursor
 
-Returns:   the next record from the file, or
+Returns:   the next *key* (nul-terminated) from the file, or
            NULL if there are no more
 */
 
@@ -628,7 +623,7 @@ for (uschar * key = dbfn_scan(dbm, TRUE, &cursor);
          print_time(retry->first_failed));
        printf("%s  ", print_time(retry->last_try));
        printf("%s %s\n", print_time(retry->next_try),
-         (retry->expired)? "*" : "");
+         retry->expired ? "*" : "");
        break;
 
       case type_wait:
@@ -1427,3 +1422,5 @@ return 0;
 #endif  /* EXIM_TIDYDB */
 
 /* End of exim_dbutil.c */
+/* vi: aw ai sw=2
+*/