X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/9242a7e8cfa94bbc9dd7eca6bd651b569b871c4e..85defcf0e9e4187107b8a1a5138ef9590ac3892c:/src/src/spool_in.c

diff --git a/src/src/spool_in.c b/src/src/spool_in.c
index 2a99c63dd..cd74d1ee7 100644
--- a/src/src/spool_in.c
+++ b/src/src/spool_in.c
@@ -2,7 +2,7 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2017 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Functions for reading spool files. When compiling for a utility (eximon),
@@ -57,9 +57,17 @@ for (i = 0; i < 2; i++)
   fname = spool_fname(US"input", message_subdir, id, US"-D");
   DEBUG(D_deliver) debug_printf("Trying spool file %s\n", fname);
 
+  /* We protect against symlink attacks both in not propagating the
+   * file-descriptor to other processes as we exec, and also ensuring that we
+   * don't even open symlinks.
+   * No -D file inside the spool area should be a symlink.
+   */
   if ((fd = Uopen(fname,
 #ifdef O_CLOEXEC
 		      O_CLOEXEC |
+#endif
+#ifdef O_NOFOLLOW
+		      O_NOFOLLOW |
 #endif
 		      O_RDWR | O_APPEND, 0)) >= 0)
     break;
@@ -206,49 +214,13 @@ return TRUE;
 
 
 
-/*************************************************
-*             Read spool header file             *
-*************************************************/
-
-/* This function reads a spool header file and places the data into the
-appropriate global variables. The header portion is always read, but header
-structures are built only if read_headers is set true. It isn't, for example,
-while generating -bp output.
-
-It may be possible for blocks of nulls (binary zeroes) to get written on the
-end of a file if there is a system crash during writing. It was observed on an
-earlier version of Exim that omitted to fsync() the files - this is thought to
-have been the cause of that incident, but in any case, this code must be robust
-against such an event, and if such a file is encountered, it must be treated as
-malformed.
-
-As called from deliver_message() (at least) we are running as root.
-
-Arguments:
-  name          name of the header file, including the -H
-  read_headers  TRUE if in-store header structures are to be built
-  subdir_set    TRUE is message_subdir is already set
-
-Returns:        spool_read_OK        success
-                spool_read_notopen   open failed
-                spool_read_enverror  error in the envelope portion
-                spool_read_hdrerror  error in the header portion
-*/
-
-int
-spool_read_header(uschar *name, BOOL read_headers, BOOL subdir_set)
-{
-FILE *f = NULL;
-int n;
-int rcount = 0;
-long int uid, gid;
-BOOL inheader = FALSE;
-uschar *p;
-
 /* Reset all the global variables to their default values. However, there is
 one exception. DO NOT change the default value of dont_deliver, because it may
 be forced by an external setting. */
 
+void
+spool_clear_header_globals(void)
+{
 acl_var_c = acl_var_m = NULL;
 authenticated_id = NULL;
 authenticated_sender = NULL;
@@ -267,7 +239,9 @@ host_lookup_failed = FALSE;
 interface_address = NULL;
 interface_port = 0;
 local_error_message = FALSE;
+#ifdef HAVE_LOCAL_SCAN
 local_scan_data = NULL;
+#endif
 max_received_linelength = 0;
 message_linecount = 0;
 received_protocol = NULL;
@@ -297,12 +271,12 @@ bmi_verdicts = NULL;
 #ifndef DISABLE_DKIM
 dkim_signers = NULL;
 dkim_disable_verify = FALSE;
-dkim_collect_input = FALSE;
+dkim_collect_input = 0;
 #endif
 
 #ifdef SUPPORT_TLS
 tls_in.certificate_verified = FALSE;
-# ifdef EXPERIMENTAL_DANE
+# ifdef SUPPORT_DANE
 tls_in.dane_verified = FALSE;
 # endif
 tls_in.cipher = NULL;
@@ -328,6 +302,53 @@ message_utf8_downconvert = 0;
 
 dsn_ret = 0;
 dsn_envid = NULL;
+}
+
+
+/*************************************************
+*             Read spool header file             *
+*************************************************/
+
+/* This function reads a spool header file and places the data into the
+appropriate global variables. The header portion is always read, but header
+structures are built only if read_headers is set true. It isn't, for example,
+while generating -bp output.
+
+It may be possible for blocks of nulls (binary zeroes) to get written on the
+end of a file if there is a system crash during writing. It was observed on an
+earlier version of Exim that omitted to fsync() the files - this is thought to
+have been the cause of that incident, but in any case, this code must be robust
+against such an event, and if such a file is encountered, it must be treated as
+malformed.
+
+As called from deliver_message() (at least) we are running as root.
+
+Arguments:
+  name          name of the header file, including the -H
+  read_headers  TRUE if in-store header structures are to be built
+  subdir_set    TRUE is message_subdir is already set
+
+Returns:        spool_read_OK        success
+                spool_read_notopen   open failed
+                spool_read_enverror  error in the envelope portion
+                spool_read_hdrerror  error in the header portion
+*/
+
+int
+spool_read_header(uschar *name, BOOL read_headers, BOOL subdir_set)
+{
+FILE *f = NULL;
+int n;
+int rcount = 0;
+long int uid, gid;
+BOOL inheader = FALSE;
+uschar *p;
+
+/* Reset all the global variables to their default values. However, there is
+one exception. DO NOT change the default value of dont_deliver, because it may
+be forced by an external setting. */
+
+spool_clear_header_globals();
 
 /* Generate the full name and open the file. If message_subdir is already
 set, just look in the given directory. Otherwise, look in both the split
@@ -578,8 +599,10 @@ for (;;)
       sender_local = TRUE;
     else if (Ustrcmp(big_buffer, "-localerror") == 0)
       local_error_message = TRUE;
+#ifdef HAVE_LOCAL_SCAN
     else if (Ustrncmp(p, "ocal_scan ", 10) == 0)
       local_scan_data = string_copy(big_buffer + 12);
+#endif
     break;
 
     case 'm':