X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/0a6c178c6c5f45668b5bb37b8be723cc9d1e72ae..ea19ad2276a93548c8a799b1466fd7996c48be04:/src/src/dbfn.c

diff --git a/src/src/dbfn.c b/src/src/dbfn.c
index 5529fe93f..a37271f36 100644
--- a/src/src/dbfn.c
+++ b/src/src/dbfn.c
@@ -2,7 +2,8 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2015 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) The Exim Maintainers 2020 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 
@@ -72,6 +73,7 @@ Arguments:
   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.
@@ -85,7 +87,7 @@ moment I haven't changed them.
 */
 
 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;
@@ -93,6 +95,8 @@ BOOL created = FALSE;
 flock_t lock_data;
 uschar dirname[256], filename[256];
 
+DEBUG(D_hints_lookup) acl_level++;
+
 /* 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. Early versions tried to lock on the open database itself, but that
@@ -112,15 +116,16 @@ snprintf(CS filename, sizeof(filename), "%s/%s.lockfile", dirname, name);
 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);
   }
 
 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;
   }
 
@@ -131,12 +136,12 @@ lock_data.l_type = read_only? F_RDLCK : F_WRLCK;
 lock_data.l_whence = lock_data.l_start = lock_data.l_len = 0;
 
 DEBUG(D_hints_lookup|D_retry|D_route|D_deliver)
-  debug_printf("locking %s\n", filename);
+  debug_printf_indent("locking %s\n", filename);
 
 sigalrm_seen = FALSE;
-alarm(EXIMDB_LOCK_TIMEOUT);
+ALARM(EXIMDB_LOCK_TIMEOUT);
 rc = fcntl(dbblock->lockfd, F_SETLKW, &lock_data);
-alarm(0);
+ALARM_CLR(0);
 
 if (sigalrm_seen) errno = ETIMEDOUT;
 if (rc < 0)
@@ -146,10 +151,11 @@ if (rc < 0)
     errno == ETIMEDOUT ? "timed out" : strerror(errno));
   (void)close(dbblock->lockfd);
   errno = 0;       /* Indicates locking failure */
+  DEBUG(D_hints_lookup) acl_level--;
   return NULL;
   }
 
-DEBUG(D_hints_lookup) debug_printf("locked  %s\n", filename);
+DEBUG(D_hints_lookup) debug_printf_indent("locked  %s\n", filename);
 
 /* 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. If we are
@@ -166,7 +172,7 @@ EXIM_DBOPEN(filename, dirname, flags, EXIMDB_MODE, &(dbblock->dbptr));
 if (!dbblock->dbptr && errno == ENOENT && flags == O_RDWR)
   {
   DEBUG(D_hints_lookup)
-    debug_printf("%s appears not to exist: trying to create\n", filename);
+    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));
   }
@@ -189,26 +195,29 @@ but creation of the database file failed. */
 
 if (created && geteuid() == root_uid)
   {
-  DIR *dd;
-  struct dirent *ent;
+  DIR * dd;
   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("ensuring %s is owned by exim\n", filename);
-        if (Uchown(filename, exim_uid, exim_gid))
-          DEBUG(D_hints_lookup) debug_printf("failed setting %s to owned by exim\n", filename);
-        }
-      }
+  if ((dd = exim_opendir(filename)))
+    for (struct dirent *ent; ent = readdir(dd); )
+      if (Ustrncmp(ent->d_name, name, namelen) == 0)
+	{
+	struct stat statbuf;
+	/* Filenames from readdir() are trusted,
+	so use a taint-nonchecking copy */
+	strcpy(CS lastname, CCS 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);
   }
@@ -219,20 +228,22 @@ exist. */
 
 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("%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;
+  DEBUG(D_hints_lookup) acl_level--;
   return NULL;
   }
 
 DEBUG(D_hints_lookup)
-  debug_printf("opened hints database %s: flags=%s\n", filename,
+  debug_printf_indent("opened hints database %s: flags=%s\n", filename,
     flags == O_RDONLY ? "O_RDONLY"
     : flags == O_RDWR ? "O_RDWR"
     : flags == (O_RDWR|O_CREAT) ? "O_RDWR|O_CREAT"
@@ -263,7 +274,8 @@ dbfn_close(open_db *dbblock)
 {
 EXIM_DBCLOSE(dbblock->dbptr);
 (void)close(dbblock->lockfd);
-DEBUG(D_hints_lookup) debug_printf("closed hints database and lockfile\n");
+DEBUG(D_hints_lookup)
+  { debug_printf_indent("closed hints database and lockfile\n"); acl_level--; }
 }
 
 
@@ -296,11 +308,11 @@ dbfn_read_with_length(open_db *dbblock, const uschar *key, int *length)
 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, is_tainted(key));
 
 memcpy(key_copy, key, klen);
 
-DEBUG(D_hints_lookup) debug_printf("dbfn_read: key=%s\n", key);
+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. */
@@ -309,7 +321,10 @@ EXIM_DATUM_SIZE(key_datum) = klen;
 
 if (!EXIM_DBGET(dbblock->dbptr, key_datum, result_datum)) return NULL;
 
-yield = store_get(EXIM_DATUM_SIZE(result_datum));
+/* 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), TRUE);
 memcpy(yield, EXIM_DATUM_DATA(result_datum), EXIM_DATUM_SIZE(result_datum));
 if (length != NULL) *length = EXIM_DATUM_SIZE(result_datum);
 
@@ -340,12 +355,12 @@ dbfn_write(open_db *dbblock, const uschar *key, void *ptr, int length)
 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, is_tainted(key));
 
 memcpy(key_copy, key, klen);
 gptr->time_stamp = time(NULL);
 
-DEBUG(D_hints_lookup) debug_printf("dbfn_write: key=%s\n", key);
+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. */
@@ -374,7 +389,9 @@ int
 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, is_tainted(key));
+
+DEBUG(D_hints_lookup) debug_printf_indent("dbfn_delete: key=%s\n", key);
 
 memcpy(key_copy, key, klen);
 EXIM_DATUM key_datum;
@@ -407,7 +424,8 @@ dbfn_scan(open_db *dbblock, BOOL start, EXIM_CURSOR **cursor)
 {
 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 */
 
@@ -526,7 +544,7 @@ while (Ufgets(buffer, 256, stdin) != NULL)
       }
 
     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)