+++ /dev/null
-Description: Allow one to use and switch between different local_scan functions
- without recompiling exim.
- http://marc.merlins.org/linux/exim/files/sa-exim-current/ Original patch from
- David Woodhouse, modified first by Derrick 'dman' Hudson and then by Marc
- MERLIN for SA-Exim and minor/major API version tracking
-Author: David Woodhouse, Derrick 'dman' Hudson, Marc MERLIN
-Origin: other, http://marc.merlins.org/linux/exim/files/sa-exim-current/
-Forwarded: no
-Last-Update: 2019-10-20
-
---- a/src/EDITME
-+++ b/src/EDITME
-@@ -868,6 +868,21 @@ HEADERS_CHARSET="ISO-8859-1"
-
-
- #------------------------------------------------------------------------------
-+# 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.
-+
-+LDFLAGS += -rdynamic
-+CFLAGS += -fvisibility=hidden
-+
-+#------------------------------------------------------------------------------
- # 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
---- a/src/config.h.defaults
-+++ b/src/config.h.defaults
-@@ -33,6 +33,8 @@ Do not put spaces between # and the 'def
-
- #define AUTH_VARS 3
-
-+#define DLOPEN_LOCAL_SCAN
-+
- #define BIN_DIRECTORY
-
- #define CONFIGURE_FILE
---- a/src/globals.c
-+++ b/src/globals.c
-@@ -115,6 +115,10 @@ int dsn_ret = 0;
- const pcre *regex_DSN = NULL;
- uschar *dsn_advertise_hosts = NULL;
-
-+#ifdef DLOPEN_LOCAL_SCAN
-+uschar *local_scan_path = NULL;
-+#endif
-+
- #ifndef DISABLE_TLS
- BOOL gnutls_compat_mode = FALSE;
- BOOL gnutls_allow_auto_pkcs11 = FALSE;
---- a/src/globals.h
-+++ b/src/globals.h
-@@ -144,6 +144,9 @@ extern int dsn_ret; /
- extern const pcre *regex_DSN; /* For recognizing DSN settings */
- extern uschar *dsn_advertise_hosts; /* host for which TLS is advertised */
-
-+#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. */
-
---- a/src/local_scan.c
-+++ b/src/local_scan.c
-@@ -6,22 +6,6 @@
- /* See the file NOTICE for conditions of use and distribution. */
-
-
--/******************************************************************************
--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
--
--HAVE_LOCAL_SCAN=yes
--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! */
-@@ -29,37 +13,129 @@ release. Use only the documented interfa
- #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 */
---- a/src/local_scan.h
-+++ b/src/local_scan.h
-@@ -17,6 +17,7 @@ settings, and the store functions. */
-
- #include <stdarg.h>
- #include <sys/types.h>
-+#pragma GCC visibility push(default)
- #include "config.h"
- #include "mytypes.h"
- #include "store.h"
-@@ -149,6 +150,9 @@ extern header_line *header_list; /
- extern BOOL host_checking; /* Set when checking a host */
- extern uschar *interface_address; /* Interface for incoming call */
- extern int interface_port; /* Port number for incoming call */
-+#ifdef DLOPEN_LOCAL_SCAN
-+extern uschar *local_scan_path;
-+#endif
- extern uschar *message_id; /* Internal id of message being handled */
- extern uschar *received_protocol; /* Name of incoming protocol */
- extern int recipients_count; /* Number of recipients */
-@@ -207,4 +211,6 @@ extern uschar * string_copyn_function(co
- extern uschar * string_copy_taint_function(const uschar *, BOOL tainted);
- #endif
-
-+#pragma GCC visibility pop
-+
- /* End of local_scan.h */
---- a/src/readconf.c
-+++ b/src/readconf.c
-@@ -203,6 +203,9 @@ static optionlist optionlist_config[] =
- { "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
- #ifdef HAVE_LOCAL_SCAN
- { "local_scan_timeout", opt_time, &local_scan_timeout },
- #endif
---- a/src/string.c
-+++ b/src/string.c
-@@ -413,6 +413,7 @@ return ss;
-
- #if (defined(HAVE_LOCAL_SCAN) || defined(EXPAND_DLFUNC)) \
- && !defined(MACRO_PREDEF) && !defined(COMPILE_UTILITY)
-+#pragma GCC visibility push(default)
- /*************************************************
- * Copy and save string *
- *************************************************/
-@@ -465,6 +466,7 @@ Ustrncpy(ss, s, n);
- ss[n] = 0;
- return ss;
- }
-+#pragma GCC visibility pop
- #endif
-
-
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