Add support for User Statically Defined Tracing (USDT) probes

This adds support for User Statically Defined Tracing (USDT).  On
Linux, this uses the header from SystemTap and dtrace utility, but the
support is universal as long as dtrace is available.

Also add the required infrastructure to add probes to libisc, libdns and
libns libraries, where most of the probes will be.

Author: oerdnj

Makefile.am

@@ -8,8 +8,8 @@ SUBDIRS += tests
 # run fuzz tests before system tests
 SUBDIRS += fuzz bin
 
-BUILT_SOURCES = bind.keys.h
-CLEANFILES = bind.keys.h
+BUILT_SOURCES += bind.keys.h
+CLEANFILES += bind.keys.h
 
 bind.keys.h: bind.keys Makefile
 	${PERL} ${top_srcdir}/util/bindkeys.pl ${top_srcdir}/bind.keys > $@
@@ -19,6 +19,7 @@ bind.keys.h: bind.keys Makefile
 EXTRA_DIST =			\
 	bind.keys		\
 	util/bindkeys.pl	\
+	util/dtrace.sh		\
 	contrib			\
 	CHANGES			\
 	COPYRIGHT		\

Makefile.dtrace

@@ -0,0 +1,18 @@
+# Hey Emacs, this is -*- makefile-automake -*- file!
+# vim: filetype=automake
+
+AM_V_DTRACE = $(AM_V_DTRACE_@AM_V@)
+AM_V_DTRACE_ = $(AM_V_DTRACE_@AM_DEFAULT_V@)
+AM_V_DTRACE_0 = @echo "  DTRACE   $@";
+
+BUILT_SOURCES += probes.h
+CLEANFILES += probes.h probes.o
+
+probes.h: probes.d
+	$(AM_V_DTRACE)$(DTRACE) -s $(srcdir)/probes.d -h -o $@
+probes.lo: probes.d $(DTRACE_DEPS)
+	$(AM_V_DTRACE)$(LIBTOOL) --mode=compile --tag=CC $(DTRACE) -s $(srcdir)/probes.d -G -o $@ $(DTRACE_OBJS)
+
+if HAVE_DTRACE
+DTRACE_LIBADD = probes.lo
+endif

Makefile.top

@@ -15,6 +15,9 @@ AM_LDFLAGS =					\
 	$(STD_LDFLAGS)
 LDADD =
 
+BUILT_SOURCES =
+CLEANFILES =
+
 if HOST_MACOS
 AM_LDFLAGS +=					\
 	-Wl,-flat_namespace
@@ -26,19 +29,28 @@ LIBISC_CFLAGS =						\
 	-I$(top_builddir)/lib/isc/include
 
 LIBISC_LIBS = $(top_builddir)/lib/isc/libisc.la
+if HAVE_DTRACE
+LIBISC_DTRACE = $(top_builddir)/lib/isc/probes.lo
+endif
 
 LIBDNS_CFLAGS = \
 	-I$(top_srcdir)/lib/dns/include			\
 	-I$(top_builddir)/lib/dns/include
 
 LIBDNS_LIBS = \
 	$(top_builddir)/lib/dns/libdns.la
+if HAVE_DTRACE
+LIBDNS_DTRACE = $(top_builddir)/lib/dns/probes.lo
+endif
 
 LIBNS_CFLAGS = \
 	-I$(top_srcdir)/lib/ns/include
 
 LIBNS_LIBS = \
 	$(top_builddir)/lib/ns/libns.la
+if HAVE_DTRACE
+LIBNS_DTRACE = $(top_builddir)/lib/ns/probes.lo
+endif
 
 LIBISCCFG_CFLAGS = \
 	-I$(top_srcdir)/lib/isccfg/include

bin/named/Makefile.am

@@ -38,8 +38,8 @@ AM_CPPFLAGS +=						\
 sbin_PROGRAMS = named
 
 nodist_named_SOURCES = xsl.c
-BUILT_SOURCES = xsl.c
-CLEANFILES = xsl.c
+BUILT_SOURCES += xsl.c
+CLEANFILES += xsl.c
 
 EXTRA_DIST = bind9.xsl
 

configure.ac

@@ -1568,6 +1568,64 @@ AC_CHECK_HEADERS([glob.h])
 AX_GCC_FUNC_ATTRIBUTE([constructor])
 AX_GCC_FUNC_ATTRIBUTE([destructor])
 
+#
+# Check whether to enable User Statically Defined Tracing.
+#
+# This is supported only on Linux now and requires SystemTap libraries.
+#
+# [pairwise: --enable-tracing=auto, --enable-tracing=yes, --disable-tracing]
+AC_ARG_ENABLE([tracing],
+	      [AS_HELP_STRING([--enable-tracing],
+			      [enable User Statically Defined Tracing])],
+	      [],
+	      [enable_tracing=auto])
+
+AC_ARG_VAR([DTRACE], [path to dtrace binary used to build User Statically Defined Tracing probes])
+AC_PATH_PROGS([DTRACE], [dtrace])
+AC_CHECK_HEADERS([sys/sdt.h])
+
+AC_MSG_CHECKING([whether to enable User Statically Defined Tracing support (default is auto)])
+AS_CASE([$enable_tracing],
+	[auto],	[enable_tracing=yes
+		 AS_IF([test "$ac_cv_header_sys_sdt_h" != "yes"], [enable_tracing=no])
+		 AS_IF([test -z "$DTRACE"],[enable_tracing=no])
+		 AC_COMPILE_IFELSE(
+		   [AC_LANG_PROGRAM([[]],
+				    [[#if !defined(__has_feature)
+				      #define __has_feature(x) 0
+				      #endif /* if !defined(__has_feature) */
+				      #if __has_feature(address_sanitizer)
+				      #define __SANITIZE_ADDRESS__ 1
+				      #endif /* if __has_feature(address_sanitizer) */
+				      #if defined(__SANITIZE_ADDRESS__)
+				      #error Address Sanitizer enabled
+				      #endif
+				     ]])],
+		   [],
+		   [enable_tracing=no]
+		 )])
+AS_CASE([$enable_tracing],
+	[yes], [AS_IF([test "$ac_cv_header_sys_sdt_h" != "yes"],
+		      [AC_MSG_ERROR([sys/sdt.h header not found])])
+		AS_IF([test -z "$DTRACE"],
+		      [AC_MSG_ERROR([The dtrace command not found])])
+		AC_MSG_RESULT([yes])],
+	[DTRACE=""
+	 AC_MSG_RESULT([no])])
+
+AS_CASE([$host],
+	[*-linux*],[have_systemtap=true])
+
+AM_CONDITIONAL([HAVE_SYSTEMTAP], [test -n "$have_systemtap"])
+AM_CONDITIONAL([HAVE_DTRACE], [test -n "$DTRACE"])
+
+# Use shim script if dtrace is not available
+AS_IF([test -z "$DTRACE"],
+      [DTRACE='$(top_srcdir)/util/dtrace.sh'])
+
+AC_SUBST([DTRACE])
+
+
 #
 # Files to configure.  These are listed here because we used to
 # specify them as arguments to AC_OUTPUT.

doc/man/Makefile.am

@@ -123,7 +123,7 @@ EXTRA_DIST =				\
 	$(MANPAGES_RST)			\
 	$(MANPAGES_IN)
 
-CLEANFILES =				\
+CLEANFILES +=				\
 	$(man_MANS)
 
 #

doc/misc/Makefile.am

@@ -37,7 +37,7 @@ cfg_test_LDADD =			\
 	$(LIBDNS_LIBS)			\
 	$(LIBISCCFG_LIBS)
 
-BUILT_SOURCES =				\
+BUILT_SOURCES +=				\
 	$(OPTIONS_FILES)
 
 rndc.grammar: cfg_test

lib/dns/.gitignore

@@ -6,4 +6,5 @@ enumtype.h
 rdatastruct.h
 gen.dSYM
 dnstap.pb-c.c
-dnstap.pb-c.h
+dnstap.pb-c.h
+/probes.h

lib/dns/Makefile.am

@@ -12,10 +12,10 @@ nodist_libdns_la_SOURCES =		\
 	$(nodist_libdns_la_HEADERS)	\
 	code.h
 
-BUILT_SOURCES =				\
+BUILT_SOURCES +=			\
 	$(nodist_libdns_la_SOURCES)
 
-CLEANFILES =				\
+CLEANFILES +=				\
 	$(nodist_libdns_la_SOURCES)	\
 	gen$(BUILD_EXEEXT)
 
@@ -124,6 +124,7 @@ libdns_la_HEADERS =			\
 	include/dns/ssu.h		\
 	include/dns/stats.h		\
 	include/dns/time.h		\
+	include/dns/trace.h		\
 	include/dns/transport.h		\
 	include/dns/tkey.h		\
 	include/dns/trace.h		\
@@ -208,6 +209,7 @@ libdns_la_SOURCES =			\
 	order.c				\
 	peer.c				\
 	private.c			\
+	probes.d			\
 	qp.c				\
 	qp_p.h				\
 	rbt.c				\
@@ -330,3 +332,12 @@ if HAVE_LMDB
 libdns_la_CPPFLAGS += $(LMDB_CFLAGS)
 libdns_la_LIBADD += $(LMDB_LIBS)
 endif
+
+if !HAVE_SYSTEMTAP
+DTRACE_DEPS = libdns_la-xfrin.lo
+DTRACE_OBJS = .libs/libdns_la-xfrin.$(OBJEXT)
+endif
+
+include $(top_srcdir)/Makefile.dtrace
+
+libdns_la_LIBADD += $(DTRACE_LIBADD)

lib/dns/probes.d

@@ -0,0 +1,15 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+provider libdns {
+};