--
On Sun, Mar 16, 2003 at 10:03:49AM +0100, Nico Erfurth wrote:
> #define LOCAL_SCAN_ABI_VERSION_MAJOR 1
> #define LOCAL_SCAN_ABI_VERSION_MINOR 0
> #define LOCAL_SCAN_ABI_VERSION \
> LOCAL_SCAN_ABI_VERSION_MAJOR.LOCAL_SCAN_ABI_VERSION_MINOR
>
> This allows easy compiletime-checking to make a patch work with different
> ABIs.
Philip, here's a new version of the patch.
The only portion that would really help us if you included it is:
--- exim-4.14-0/src/local_scan.h Tue Mar 11 04:20:20 2003
+++ exim-4.14-1/src/local_scan.h Sun Mar 23 15:34:57 2003
@@ -71,6 +71,15 @@
#define SPOOL_DATA_START_OFFSET (MESSAGE_ID_LENGTH+3)
+/* local_scan() ABI version number for dynamic libraries
+ The major number is increased when the ABI is changed in a non
+ backward compatible way.
+ The minor number is increased each time a new feature is added (in a
+ way that doesn't break backward compatibility) -- Marc */
+#define LOCAL_SCAN_ABI_VERSION_MAJOR 1
+#define LOCAL_SCAN_ABI_VERSION_MINOR 0
+#define LOCAL_SCAN_ABI_VERSION \
+ LOCAL_SCAN_ABI_VERSION_MAJOR.LOCAL_SCAN_ABI_VERSION_MINOR
/* Structure definitions that are documented as visible in the function. */
After the dlopen patch matures a little more, it probably would be nice
to have it in exim (it's a define afterall, so it shouldn't change the
common case), but in the meantime, we can continue to maintain it
separately.
I have attached a full copy of the new version of the patch.
Thanks,
Marc
--
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems & security ....
.... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/ | Finger marc_f@??? for PGP key
--
diff -urN exim-4.14-0/src/EDITME exim-4.14-1/src/EDITME
--- exim-4.14-0/src/EDITME Tue Mar 11 04:20:18 2003
+++ exim-4.14-1/src/EDITME Sun Mar 23 15:34:15 2003
@@ -388,6 +388,20 @@
#------------------------------------------------------------------------------
+# On systems which support dynamic loading of shared libraries, Exim can
+# load a local_scan function specified in its config file instead of having
+# to be recompiled with the desired local_scan function. For a full
+# description of the API to this function, see the Exim specification.
+
+DLOPEN_LOCAL_SCAN=yes
+
+# If you set DLOPEN_LOCAL_SCAN, then you need to include -rdynamic in the
+# linker flags. Without it, the loaded .so won't be able to access any
+# functions from exim.
+
+LFLAGS=-rdynamic
+
+#------------------------------------------------------------------------------
# The default distribution of Exim contains only the plain text form of the
# documentation. Other forms are available separately. If you want to install
# the documentation in "info" format, first fetch the Texinfo documentation
diff -urN exim-4.14-0/src/config.h.defaults exim-4.14-1/src/config.h.defaults
--- exim-4.14-0/src/config.h.defaults Tue Mar 11 04:20:19 2003
+++ exim-4.14-1/src/config.h.defaults Sun Mar 23 15:34:15 2003
@@ -17,6 +17,8 @@
#define AUTH_PLAINTEXT
#define AUTH_SPA
+#define DLOPEN_LOCAL_SCAN
+
#define BIN_DIRECTORY
#define CONFIGURE_FILE
diff -urN exim-4.14-0/src/globals.c exim-4.14-1/src/globals.c
--- exim-4.14-0/src/globals.c Tue Mar 11 04:20:20 2003
+++ exim-4.14-1/src/globals.c Sun Mar 23 15:34:15 2003
@@ -103,6 +103,9 @@
uschar *tls_verify_hosts = NULL;
#endif
+#ifdef DLOPEN_LOCAL_SCAN
+uschar *local_scan_path = NULL;
+#endif
/* Input-reading functions for messages, so we can use special ones for
incoming TCP/IP. The defaults use stdin. We never need these for any
diff -urN exim-4.14-0/src/globals.h exim-4.14-1/src/globals.h
--- exim-4.14-0/src/globals.h Tue Mar 11 04:20:20 2003
+++ exim-4.14-1/src/globals.h Sun Mar 23 15:34:15 2003
@@ -67,6 +67,9 @@
extern uschar *tls_verify_hosts; /* Mandatory client verification */
#endif
+#ifdef DLOPEN_LOCAL_SCAN
+extern uschar *local_scan_path; /* Path to local_scan() library */
+#endif
/* Input-reading functions for messages, so we can use special ones for
incoming TCP/IP. */
diff -urN exim-4.14-0/src/local_scan.c exim-4.14-1/src/local_scan.c
--- exim-4.14-0/src/local_scan.c Tue Mar 11 04:20:20 2003
+++ exim-4.14-1/src/local_scan.c Sun Mar 23 15:34:15 2003
@@ -5,60 +5,131 @@
/* Copyright (c) University of Cambridge 1995 - 2003 */
/* See the file NOTICE for conditions of use and distribution. */
+#include "exim.h"
-/******************************************************************************
-This file contains a template local_scan() function that just returns ACCEPT.
-If you want to implement your own version, you should copy this file to, say
-Local/local_scan.c, and edit the copy. To use your version instead of the
-default, you must set
-
-LOCAL_SCAN_SOURCE=Local/local_scan.c
-
-in your Local/Makefile. This makes it easy to copy your version for use with
-subsequent Exim releases.
-
-For a full description of the API to this function, see the Exim specification.
-******************************************************************************/
-
-
-/* This is the only Exim header that you should include. The effect of
-including any other Exim header is not defined, and may change from release to
-release. Use only the documented interface! */
-
-#include "local_scan.h"
-
-
-/* This is a "do-nothing" version of a local_scan() function. The arguments
-are:
-
- fd The file descriptor of the open -D file, which contains the
- body of the message. The file is open for reading and
- writing, but modifying it is dangerous and not recommended.
-
- return_text A pointer to an unsigned char* variable which you can set in
- order to return a text string. It is initialized to NULL.
-
-The return values of this function are:
-
- LOCAL_SCAN_ACCEPT
- The message is to be accepted. The return_text argument is
- saved in $local_scan_data.
-
- LOCAL_SCAN_REJECT
- The message is to be rejected. The returned text is used
- in the rejection message.
-
- LOCAL_SCAN_TEMPREJECT
- This specifies a temporary rejection. The returned text
- is used in the rejection message.
-*/
+#ifdef DLOPEN_LOCAL_SCAN
+#include <dlfcn.h>
+static int (*local_scan_fn)(int fd, uschar **return_text) = NULL;
+static int load_local_scan_library(void);
+#endif
int
local_scan(int fd, uschar **return_text)
{
fd = fd; /* Keep picky compilers happy */
return_text = return_text;
-return LOCAL_SCAN_ACCEPT;
+#ifdef DLOPEN_LOCAL_SCAN
+/* local_scan_path is defined AND not the empty string */
+if (local_scan_path && *local_scan_path)
+ {
+ if (!local_scan_fn)
+ {
+ if (!load_local_scan_library())
+ {
+ char *base_msg , *error_msg , *final_msg ;
+ int final_length = -1 ;
+
+ base_msg=US"Local configuration error - local_scan() library failure\n";
+ error_msg = dlerror() ;
+
+ final_length = strlen(base_msg) + strlen(error_msg) + 1 ;
+ final_msg = (char*)malloc( final_length*sizeof(char) ) ;
+ *final_msg = '\0' ;
+
+ strcat( final_msg , base_msg ) ;
+ strcat( final_msg , error_msg ) ;
+
+ *return_text = final_msg ;
+ return LOCAL_SCAN_TEMPREJECT;
+ }
+ }
+ return local_scan_fn(fd, return_text);
+ }
+else
+#endif
+ return LOCAL_SCAN_ACCEPT;
+}
+
+#ifdef DLOPEN_LOCAL_SCAN
+
+static int load_local_scan_library(void)
+{
+/* No point in keeping local_scan_lib since we'll never dlclose() anyway */
+void *local_scan_lib = NULL;
+int (*local_scan_version_fn)(void);
+int vers_maj;
+int vers_min;
+
+local_scan_lib = dlopen(local_scan_path, RTLD_NOW);
+if (!local_scan_lib)
+ {
+ log_write(0, LOG_MAIN|LOG_REJECT, "local_scan() library open failed - "
+ "message temporarily rejected");
+ return FALSE;
+ }
+
+local_scan_version_fn = dlsym(local_scan_lib, "local_scan_version_major");
+if (!local_scan_version_fn)
+ {
+ dlclose(local_scan_lib);
+ log_write(0, LOG_MAIN|LOG_REJECT, "local_scan() library doesn't contain "
+ "local_scan_version_major() function - message temporarily rejected");
+ return FALSE;
+ }
+
+/* The major number is increased when the ABI is changed in a non
+ backward compatible way. */
+vers_maj = local_scan_version_fn();
+
+local_scan_version_fn = dlsym(local_scan_lib, "local_scan_version_minor");
+if (!local_scan_version_fn)
+ {
+ dlclose(local_scan_lib);
+ log_write(0, LOG_MAIN|LOG_REJECT, "local_scan() library doesn't contain "
+ "local_scan_version_minor() function - message temporarily rejected");
+ return FALSE;
+ }
+
+/* The minor number is increased each time a new feature is added (in a
+ way that doesn't break backward compatibility) -- Marc */
+vers_min = local_scan_version_fn();
+
+
+if (vers_maj != LOCAL_SCAN_ABI_VERSION_MAJOR)
+ {
+ dlclose(local_scan_lib);
+ local_scan_lib = NULL;
+ log_write(0, LOG_MAIN|LOG_REJECT, "local_scan() has an incompatible major"
+ "version number, you need to recompile your module for this version"
+ "of exim (The module was compiled for version %d.%d and this exim provides"
+ "ABI version %d.%d)", vers_maj, vers_min, LOCAL_SCAN_ABI_VERSION_MAJOR,
+ LOCAL_SCAN_ABI_VERSION_MINOR);
+ return FALSE;
+ }
+else if (vers_min > LOCAL_SCAN_ABI_VERSION_MINOR)
+ {
+ dlclose(local_scan_lib);
+ local_scan_lib = NULL;
+ log_write(0, LOG_MAIN|LOG_REJECT, "local_scan() has an incompatible minor"
+ "version number, you need to recompile your module for this version"
+ "of exim (The module was compiled for version %d.%d and this exim provides"
+ "ABI version %d.%d)", vers_maj, vers_min, LOCAL_SCAN_ABI_VERSION_MAJOR,
+ LOCAL_SCAN_ABI_VERSION_MINOR);
+ return FALSE;
+ }
+
+local_scan_fn = dlsym(local_scan_lib, "local_scan");
+if (!local_scan_fn)
+ {
+ dlclose(local_scan_lib);
+ log_write(0, LOG_MAIN|LOG_REJECT, "local_scan() library doesn't contain "
+ "local_scan() function - message temporarily rejected");
+ return FALSE;
+ }
+
+return TRUE;
}
+
+#endif /* DLOPEN_LOCAL_SCAN */
/* End of local_scan.c */
diff -urN exim-4.14-0/src/local_scan.h exim-4.14-1/src/local_scan.h
--- exim-4.14-0/src/local_scan.h Tue Mar 11 04:20:20 2003
+++ exim-4.14-1/src/local_scan.h Sun Mar 23 15:34:57 2003
@@ -71,6 +71,15 @@
#define SPOOL_DATA_START_OFFSET (MESSAGE_ID_LENGTH+3)
+/* local_scan() ABI version number for dynamic libraries
+ The major number is increased when the ABI is changed in a non
+ backward compatible way.
+ The minor number is increased each time a new feature is added (in a
+ way that doesn't break backward compatibility) -- Marc */
+#define LOCAL_SCAN_ABI_VERSION_MAJOR 1
+#define LOCAL_SCAN_ABI_VERSION_MINOR 0
+#define LOCAL_SCAN_ABI_VERSION \
+ LOCAL_SCAN_ABI_VERSION_MAJOR.LOCAL_SCAN_ABI_VERSION_MINOR
/* Structure definitions that are documented as visible in the function. */
diff -urN exim-4.14-0/src/readconf.c exim-4.14-1/src/readconf.c
--- exim-4.14-0/src/readconf.c Tue Mar 11 04:20:22 2003
+++ exim-4.14-1/src/readconf.c Sun Mar 23 15:34:15 2003
@@ -182,6 +182,9 @@
{ "local_from_prefix", opt_stringptr, &local_from_prefix },
{ "local_from_suffix", opt_stringptr, &local_from_suffix },
{ "local_interfaces", opt_stringptr, &local_interfaces },
+#ifdef DLOPEN_LOCAL_SCAN
+ { "local_scan_path", opt_stringptr, &local_scan_path },
+#endif
{ "local_scan_timeout", opt_time, &local_scan_timeout },
{ "local_sender_retain", opt_bool, &local_sender_retain },
{ "localhost_number", opt_stringptr, &host_number_string },
--
