Bug 139: portability fixes and documentation.
authorPhil Pennock <pdp@spodhuis.org>
Sun, 16 Jan 2011 07:15:53 +0000 (02:15 -0500)
committerPhil Pennock <pdp@spodhuis.org>
Sun, 16 Jan 2011 07:15:53 +0000 (02:15 -0500)
Document the dynamic lookup module capability in spec.xfpt.
Include a ChangeLog item.

Avoid the GNU-specific "export" make(1) directive.
Build the lookups Makefile using the existing framework.
Build with BSD Make once more.

The src/lookups/Makefile that is used at build time now has the dynamic
content come from scripts/lookups-Makefile.

Add CFLAGS_DYNAMIC support, which can be set in Local/Makefile.
Provide defaults for Linux & FreeBSD.

Ensure that build fails early if a dynamic module is requested but
CFLAGS_DYNAMIC is not defined.

doc/doc-docbook/spec.xfpt
doc/doc-txt/ChangeLog
src/Makefile
src/OS/Makefile-Base
src/OS/Makefile-FreeBSD
src/OS/Makefile-Linux
src/scripts/Configure-Makefile
src/scripts/MakeLinks
src/scripts/lookups-Makefile [new file with mode: 0755]
src/src/EDITME
src/src/lookups/Makefile

index 66dfab7..15b3a2b 100644 (file)
@@ -1946,6 +1946,36 @@ support has not been tested for some time.
 
 
 
+.section "Dynamically loaded lookup module support" "SECTdynamicmodules"
+.cindex "lookup modules"
+.cindex "dynamic modules"
+.cindex ".so building"
+On some platforms, Exim supports not compiling all lookup types directly into
+the main binary, instead putting some into external modules which can be loaded
+on demand.
+This permits packagers to build Exim with support for lookups with extensive
+library dependencies without requiring all users to install all of those
+dependencies.
+Most, but not all, lookup types can be built this way.
+
+Set &`LOOKUP_MODULE_DIR`& to the directory into which the modules will be
+installed; Exim will only load modules from that directory, as a security
+measure.  You will need to set &`CFLAGS_DYNAMIC`& if not already defined
+for your OS; see &_OS/Makefile-Linux_& for an example.
+Some other requirements for adjusting &`EXTRALIBS`& may also be necessary,
+see &_src/EDITME_& for details.
+
+Then, for each module to be loaded dynamically, define the relevant
+&`LOOKUP_`&<&'lookup_type'&> flags to have the value "2" instead of "yes".
+For example, this will build in lsearch but load sqlite and mysql support
+on demand:
+.code
+LOOKUP_LSEARCH=yes
+LOOKUP_SQLITE=2
+LOOKUP_MYSQL=2
+.endd
+
+
 .section "The building process" "SECID29"
 .cindex "build directory"
 Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been
@@ -34208,6 +34238,13 @@ arbitrary program's being run as exim, not as root.
 
 
 
+.section "Dynamic module directory" "SECTdynmoddir"
+Any dynamically loadable modules must be installed into the directory
+defined in &`LOOKUP_MODULE_DIR`& in &_Local/Makefile_& for Exim to permit
+loading it.
+
+
+
 .section "Use of sprintf()" "SECID279"
 .cindex "&[sprintf()]&"
 A large number of occurrences of &"sprintf"& in the code are actually calls to
index ef82a0c..e27496b 100644 (file)
@@ -14,6 +14,14 @@ TF/02 Log LMTP confirmation messages in the same way as SMTP,
 
 TF/03 Include the error message when we fail to unlink a spool file.
 
+DW/01 Bugzilla 139: Support dynamically loaded lookups as modules.
+      With thanks to Steve Haslam, Johannes Berg & Serge Demonchaux
+      for maintaining out-of-tree patches for some time.
+
+PP/01 Bugzilla 139: Documentation and portability issues.
+      Avoid GNU Makefile-isms, let Exim continue to build on BSD.
+      Handle per-OS dynamic-module compilation flags.
+
 
 Exim version 4.73
 -----------------
index eb9df50..8ad750d 100644 (file)
@@ -54,14 +54,16 @@ build-directory:
 
 configure: build-directory
        @cd build-$(buildname); \
-         build=$(build) $(SHELL) ../scripts/Configure-Makefile
+         build=$(build) $(SHELL) ../scripts/Configure-Makefile; \
+         $(SHELL) ../scripts/lookups-Makefile
 
 # The "makefile" target forces a rebuild of the makefile (as opposed to
 # "configure", which doesn't force it).
 
 makefile: build-directory
        @cd build-$(buildname); $(RM_COMMAND) -f Makefile; \
-         build=$(build) $(SHELL) ../scripts/Configure-Makefile
+         build=$(build) $(SHELL) ../scripts/Configure-Makefile; \
+         $(SHELL) ../scripts/lookups-Makefile
 
 # The installation commands are kept in a separate script, which expects
 # to be run from inside the build directory.
index 5793869..29a6ad3 100644 (file)
@@ -641,6 +641,7 @@ $(MONBIN): $(HDRS)
 
 buildlookups lookups/lookups.a: config.h
         @cd lookups; $(MAKE) SHELL=$(SHELL) AR="$(AR)" $(MFLAGS) CC="$(CC)" CFLAGS="$(CFLAGS)" \
+          CFLAGS_DYNAMIC="$(CFLAGS_DYNAMIC)" \
           FE="$(FE)" RANLIB="$(RANLIB)" RM_COMMAND="$(RM_COMMAND)" HDRS="$(PHDRS)" \
           INCLUDE="$(INCLUDE) $(IPV6_INCLUDE) $(TLS_INCLUDE) $(LOOKUP_INCLUDE)"; \
         echo " "
index c0f75ee..3a2697b 100644 (file)
@@ -15,6 +15,9 @@ HAVE_SA_LEN=YES
 # crypt() is in a separate library
 LIBS=-lcrypt -lm -lutil
 
+# Dynamicly loaded modules need to be built with -fPIC
+CFLAGS_DYNAMIC=-shared -rdynamic -fPIC
+
 # FreeBSD always ships with Berkeley DB
 USE_DB=yes
 
index cc8dce7..4fe2436 100644 (file)
@@ -11,6 +11,7 @@ CHGRP_COMMAND=look_for_it
 CHMOD_COMMAND=look_for_it
 
 CFLAGS=-O -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE
+CFLAGS_DYNAMIC=-shared -rdynamic
 
 DBMLIB = -ldb
 USE_DB = yes
index 1b2ea1e..abef500 100755 (executable)
@@ -78,10 +78,13 @@ mf=Makefile
 mft=$mf-t
 mftt=$mf-tt
 
+look_mf=lookups/Makefile.predynamic
+look_mft=${look_mf}-t
+
 # Ensure the temporary does not exist and start the new one by setting
 # the OSTYPE and ARCHTYPE variables.
 
-rm -f $mft $mftt
+rm -f $mft $mftt $look_mf-t
 (echo "OSTYPE=$ostype"; echo "ARCHTYPE=$archtype"; echo "") > $mft || exit 1
 
 # Now concatenate the files to the temporary file. Copy the files using sed to
@@ -107,7 +110,13 @@ do   if test -r ../$f
             echo "# End of $f"
             echo ""
      fi
-done | sed 's/^LOOKUP_/export LOOKUP_/' >> $mft || exit 1
+done >> $mft || exit 1
+
+# make the lookups Makefile with the definitions
+
+## prepend stuff here; eg: grep LOOKUP_ $mft > $look_mft
+## cat ../src/lookups/Makefile >> $look_mft
+cp ../src/lookups/Makefile $look_mft
 
 # See if there is a definition of EXIM_PERL in what we have built so far.
 # If so, run Perl to find the default values for PERL_CC, PERL_CCOPTS,
@@ -158,18 +167,20 @@ cat ../OS/Makefile-Base >> $mft || exit 1
 # If the new makefile is the same as the existing one, say so, and just
 # update the timestamp. Otherwise remove the old and install the new.
 
-if      [ -s $mf ] && cmp -s $mft $mf
+if      [ -s $mf ] && cmp -s $mft $mf && [ -s $look_mf ] && cmp -s $look_mft $look_mf
 then    echo ">>> rebuilt $mf unchanged"
         echo " "
         touch $mf || exit
         rm -f $mft
-elif    rm -f $mf
+elif    rm -f $mf $look_mf
         mv $mft $mf
-then    echo ">>> New $mf installed"
+       mv $look_mft $look_mf
+then    echo ">>> New $mf & $look_mf installed"
         echo '>>> Use "make makefile" if you need to force rebuilding of the makefile'
         echo " "
 else    echo " "
         echo "*** Failed to install $mf - see $mft"
+       echo "    (or $look_mft)"
         echo " "
         exit 1;
 fi
index 5918139..c021ace 100755 (executable)
@@ -31,7 +31,7 @@ echo ">>> Creating links to source files..."
 mkdir lookups
 cd lookups
 ln -s ../../src/lookups/README           README
-ln -s ../../src/lookups/Makefile         Makefile
+# Makefile is generated
 ln -s ../../src/lookups/cdb.c            cdb.c
 ln -s ../../src/lookups/dbmdb.c          dbmdb.c
 ln -s ../../src/lookups/dnsdb.c          dnsdb.c
diff --git a/src/scripts/lookups-Makefile b/src/scripts/lookups-Makefile
new file mode 100755 (executable)
index 0000000..7069cfb
--- /dev/null
@@ -0,0 +1,85 @@
+#! /bin/sh
+
+# We turn the configure-built build-$foo/lookups/Makefile.predynamic into Makefile
+
+input=lookups/Makefile.predynamic
+target=lookups/Makefile
+defs_source=Makefile
+tag_marker='MAGIC-TAG-MODS-OBJ-RULES-GO-HERE'
+
+tab='  '
+if grep -q "^LOOKUP.*=[ $tab]*2" "$defs_source"
+then
+  # we have work to do
+else
+  echo "No dynamic module loading support"
+  cp "$input" "$target"
+  exit 0
+fi
+
+if grep -q "^CFLAGS_DYNAMIC[ $tab]*=" "$defs_source"
+then
+  # we have a definition, we're good to go
+else
+  echo >&2 "Missing CFLAGS_DYNAMIC inhibits building dynamic module lookup"
+  exit 1
+fi
+
+tmp="$target.t"
+
+want_dynamic() {
+  local dyn_name="$1"
+  grep -q "^LOOKUP_${dyn_name}[ $tab]*=[ $tab]*2" "$defs_source"
+}
+
+want_at_all() {
+  local want_name="$1"
+  grep -q "^LOOKUP_${want_name}[ $tab]*=[ $tab]*." "$defs_source"
+}
+
+emit_module_rule() {
+  local lookup_name="$1"
+  local mod_name
+  if [ "${lookup_name%:*}" = "$lookup_name" ]
+  then
+    mod_name=$(echo $lookup_name | tr A-Z a-z)
+  else
+    mod_name="${lookup_name#*:}"
+    lookup_name="${lookup_name%:*}"
+  fi
+
+  if want_dynamic "$lookup_name"
+  then
+    echo "MODS += ${mod_name}.so"
+    echo "LOOKUP_${mod_name}_INCLUDE = \$(LOOKUP_${lookup_name}_INCLUDE)"
+    echo "LOOKUP_${mod_name}_LIBS = \$(LOOKUP_${lookup_name}_LIBS)"
+  elif want_at_all "$lookup_name"
+  then
+    echo "OBJ += ${mod_name}.o"
+  fi
+}
+
+exec 5>&1
+exec > "$tmp"
+
+sed -n "1,/$tag_marker/p" < "$input"
+
+for name_mod in \
+    CDB DBM:dbmdb DNSDB DSEARCH IBASE LSEARCH MYSQL NIS NISPLUS ORACLE \
+    PASSWD PGSQL SQLITE TESTDB WHOSON
+do
+  emit_module_rule $name_mod
+done
+
+if want_at_all LDAP
+then
+  echo "OBJ += ldap.o"
+fi
+
+sed -n "/$tag_marker/,\$p" < "$input"
+
+exec >&5
+mv "$tmp" "$target"
+
+
+# vim: set ft=sh sw=2 :
index be15e4e..74c507d 100644 (file)
@@ -252,6 +252,11 @@ TRANSPORT_SMTP=yes
 # See below for dynamic lookup modules.
 # LOOKUP_MODULE_DIR=/usr/lib/exim/lookups/
 
+# To build a module dynamically, you'll need to define CFLAGS_DYNAMIC for
+# your platform.  Eg:
+# CFLAGS_DYNAMIC=-shared -rdynamic
+# CFLAGS_DYNAMIC=-shared -rdynamic -fPIC
+
 #------------------------------------------------------------------------------
 # These settings determine which file and database lookup methods are included
 # in the binary. See the manual chapter entitled "File and database lookups"
index 76e56da..623f24f 100644 (file)
@@ -1,4 +1,8 @@
 # $Cambridge: exim/src/src/lookups/Makefile,v 1.9 2009/06/10 07:34:05 tom Exp $
+#
+# nb: at build time, the version of this file used will have had some
+#     extra variable definitions and prepended to it and module build rules
+#     interpolated below.
 
 # Make file for building all the available lookups.
 # This is called from the main make file, after cd'ing
 OBJ=spf.o
 MODS=
 
-ifeq ($(LOOKUP_CDB),2)
-MODS += cdb.so
-LOOKUP_cdb_INCLUDE = $(LOOKUP_CDB_INCLUDE)
-LOOKUP_cdb_LIBS = $(LOOKUP_CDB_LIBS)
-else
-ifneq ($(LOOKUP_CDB),)
-OBJ += cdb.o
-endif
-endif
-
-ifeq ($(LOOKUP_DBM),2)
-MODS += dbmdb.so
-LOOKUP_dbmdb_INCLUDE = $(LOOKUP_DBM_INCLUDE)
-LOOKUP_dbmdb_LIBS = $(LOOKUP_DBM_LIBS)
-else
-ifneq ($(LOOKUP_DBM),)
-OBJ += dbmdb.o
-endif
-endif
-
-ifeq ($(LOOKUP_DNSDB),2)
-MODS += dnsdb.so
-LOOKUP_dnsdb_INCLUDE = $(LOOKUP_DNSDB_INCLUDE)
-LOOKUP_dnsdb_LIBS = $(LOOKUP_DNSDB_LIBS)
-else
-ifneq ($(LOOKUP_DNSDB),)
-OBJ += dnsdb.o
-endif
-endif
-
-ifeq ($(LOOKUP_DSEARCH),2)
-MODS += dsearch.so
-LOOKUP_dsearch_INCLUDE = $(LOOKUP_DSEARCH_INCLUDE)
-LOOKUP_dsearch_LIBS = $(LOOKUP_DSEARCH_LIBS)
-else
-ifneq ($(LOOKUP_DSEARCH),)
-OBJ += dsearch.o
-endif
-endif
-
-ifeq ($(LOOKUP_IBASE),2)
-MODS += ibase.so
-LOOKUP_ibase_INCLUDE = $(LOOKUP_IBASE_INCLUDE)
-LOOKUP_ibase_LIBS = $(LOOKUP_IBASE_LIBS)
-else
-ifneq ($(LOOKUP_IBASE),)
-OBJ += ibase.o
-endif
-endif
-
-ifneq ($(LOOKUP_LDAP),)
-OBJ += ldap.o
-endif
-
-ifeq ($(LOOKUP_LSEARCH),2)
-MODS += lsearch.so
-LOOKUP_lsearch_INCLUDE = $(LOOKUP_LSEARCH_INCLUDE)
-LOOKUP_lsearch_LIBS = $(LOOKUP_LSEARCH_LIBS)
-else
-ifneq ($(LOOKUP_LSEARCH),)
-OBJ += lsearch.o
-endif
-endif
-
-ifeq ($(LOOKUP_MYSQL),2)
-MODS += mysql.so
-LOOKUP_mysql_INCLUDE = $(LOOKUP_MYSQL_INCLUDE)
-LOOKUP_mysql_LIBS = $(LOOKUP_MYSQL_LIBS)
-else
-ifneq ($(LOOKUP_MYSQL),)
-OBJ += mysql.o
-endif
-endif
-
-ifeq ($(LOOKUP_NIS),2)
-MODS += nis.so
-LOOKUP_nis_INCLUDE = $(LOOKUP_NIS_INCLUDE)
-LOOKUP_nis_LIBS = $(LOOKUP_NIS_LIBS)
-else
-ifneq ($(LOOKUP_NIS),)
-OBJ += nis.o
-endif
-endif
-
-ifeq ($(LOOKUP_NISPLUS),2)
-MODS += nisplus.so
-LOOKUP_nisplus_INCLUDE = $(LOOKUP_NISPLUS_INCLUDE)
-LOOKUP_nisplus_LIBS = $(LOOKUP_NISPLUS_LIBS)
-else
-ifneq ($(LOOKUP_NISPLUS),)
-OBJ += nisplus.o
-endif
-endif
-
-ifeq ($(LOOKUP_ORACLE),2)
-MODS += oracle.so
-LOOKUP_oracle_INCLUDE = $(LOOKUP_ORACLE_INCLUDE)
-LOOKUP_oracle_LIBS = $(LOOKUP_ORACLE_LIBS)
-else
-ifneq ($(LOOKUP_ORACLE),)
-OBJ += oracle.o
-endif
-endif
-
-ifeq ($(LOOKUP_PASSWD),2)
-MODS += passwd.so
-LOOKUP_passwd_INCLUDE = $(LOOKUP_PASSWD_INCLUDE)
-LOOKUP_passwd_LIBS = $(LOOKUP_PASSWD_LIBS)
-else
-ifneq ($(LOOKUP_PASSWD),)
-OBJ += passwd.o
-endif
-endif
-
-ifeq ($(LOOKUP_PGSQL),2)
-MODS += pgsql.so
-LOOKUP_pgsql_INCLUDE = $(LOOKUP_PGSQL_INCLUDE)
-LOOKUP_pgsql_LIBS = $(LOOKUP_PGSQL_LIBS)
-else
-ifneq ($(LOOKUP_PGSQL),)
-OBJ += pgsql.o
-endif
-endif
-
-ifeq ($(LOOKUP_SQLITE),2)
-MODS += sqlite.so
-LOOKUP_sqlite_INCLUDE = $(LOOKUP_SQLITE_INCLUDE)
-LOOKUP_sqlite_LIBS = $(LOOKUP_SQLITE_LIBS)
-else
-ifneq ($(LOOKUP_SQLITE),)
-OBJ += sqlite.o
-endif
-endif
-
-ifeq ($(LOOKUP_TESTDB),2)
-MODS += testdb.so
-LOOKUP_testdb_INCLUDE = $(LOOKUP_TESTDB_INCLUDE)
-LOOKUP_testdb_LIBS = $(LOOKUP_TESTDB_LIBS)
-else
-ifneq ($(LOOKUP_TESTDB),)
-OBJ += testdb.o
-endif
-endif
-
-ifeq ($(LOOKUP_WHOSON),2)
-MODS += whoson.so
-LOOKUP_whoson_INCLUDE = $(LOOKUP_WHOSON_INCLUDE)
-LOOKUP_whoson_LIBS = $(LOOKUP_WHOSON_LIBS)
-else
-ifneq ($(LOOKUP_WHOSON),)
-OBJ += whoson.o
-endif
-endif
+# MAGIC-TAG-MODS-OBJ-RULES-GO-HERE
 
 
 all:             lookups.a lf_quote.o lf_check_file.o lf_sqlperform.o $(MODS)
@@ -178,7 +30,7 @@ lookups.a:       $(OBJ)
                 $(FE)$(CC) -c $(CFLAGS) $(INCLUDE) $*.c
 
 .c.so:;          @echo "$(CC) -shared $*.c"
-                $(FE)$(CC) $(LOOKUP_$*_INCLUDE) $(LOOKUP_$*_LIBS) -DDYNLOOKUP -shared -rdynamic $(CFLAGS) $(INCLUDE) $(DLFLAGS) $*.c -o $@
+                $(FE)$(CC) $(LOOKUP_$*_INCLUDE) $(LOOKUP_$*_LIBS) -DDYNLOOKUP $(CFLAGS_DYNAMIC) $(CFLAGS) $(INCLUDE) $(DLFLAGS) $*.c -o $@
 
 lf_check_file.o: $(HDRS) lf_check_file.c  lf_functions.h
 lf_quote.o:      $(HDRS) lf_quote.c       lf_functions.h