faketime: use regular symbol iso nasty injection approach

macOS doesn't allow injecting symbols (any more) and it's fugly as well,
so instead of preloading, just compile a separate binary for testing
purposes using the time/gettimeofday functions from faketime.
This is activating using a define via build, and therefore function nor
override are available in the produced binary (which is good).

Signed-off-by: Fabian Groffen <[email protected]>

Makefile.am

@@ -39,8 +39,7 @@ man:
 	> relay.1
 
 bin_PROGRAMS = relay
-check_PROGRAMS = sendmetric
-lib_LTLIBRARIES = libfaketime.la
+check_PROGRAMS = relaytest sendmetric
 relay_LINK = $(CCLD) $(AM_LDFLAGS) $(LDFLAGS) -o $@
 relay_LDADD = $(LIBGZIP) $(LIBLZ4) $(LIBSNAPPY) $(LIBSSL) \
 			  $(LIBONIGURUMA) $(LIBPCRE2) $(LIBPCRE)
@@ -59,10 +58,15 @@ relay_SOURCES = \
 	collector.c \
 	aggregator.c \
 	$(NULL)
+relaytest_LINK = $(relay_LINK)
+relaytest_LDADD = $(relay_LDADD)
+relaytest_SOURCES = $(relay_SOURCES) \
+                    faketime.c
+relaytest_CPPFLAGS = $(AM_CPPFLAGS) \
+                     -Dtime=faketime -Dgettimeofday=fakegettimeofday
 sendmetric_LINK = $(CCLD) $(AM_LDFLAGS) $(LDFLAGS) -o $@
 sendmetric_LDADD = $(LIBGZIP) $(LIBLZ4) $(LIBSNAPPY) $(LIBSSL)
 sendmetric_SOURCES = sendmetric.c
-libfaketime_la_SOURCES = faketime.c
 noinst_HEADERS = \
 	relay.h \
 	md5.h \
@@ -79,6 +83,7 @@ noinst_HEADERS = \
 	collector.h \
 	aggregator.h \
 	posixregex.h \
+	faketime.h \
 	$(NULL)
 man_MANS = relay.1
 
@@ -141,12 +146,11 @@ CRTESTS += dual-ssl large-ssl dual-large-ssl dual-mtls
 endif
 
 test: check
-test-%: relay libfaketime.la sendmetric
+test-%: relaytest sendmetric
 	@( cd test && ./run-test.sh $* )
 approve-%: relay sendmetric
 	@( cd test && ./run-test.sh -a $* )
 check-local:
 	@( cd test && ./run-test.sh $(CRTESTS) )
 install-exec-local:  # libtool refuses to build shared for check or noinst trg
-	$(LIBTOOL) $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=uninstall \
-		rm -f "$(DESTDIR)$(libdir)/libfaketime.la"
+	$(LIBTOOL) $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=uninstall

faketime.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2020 Fabian Groffen
+ * Copyright 2013-2024 Fabian Groffen
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,55 +18,23 @@
 #include "config.h"
 #endif
 
-#ifndef HAVE_RTLD_NEXT
-# error must have dlsym/RTLD_NEXT to fake time
-#endif
+/* avoid overrides here, we need the real thing */
+#undef time
+#undef gettimeofday
 
-#if 0
-/* we cannot include time.h and sys/time.h due to gettimeofday
- * definition being different on some platforms with
- * complex/incompatible restrict definitions, but we do need struct
- * timeval, so we're faking the necessary bits here */
 #include <time.h>
 #include <sys/time.h>
-#else
-#define _TIME_H
-#define _SYS_TIME_H
-/* internal definition, we only access tv_sec so don't care about the
- * type/definition of tv_usec */
-#if SIZEOF_TIME_T == 4
-#define fttime_t int
-#elif SIZEOF_TIME_T == 8
-#define fttime_t long long int
-#else
-#define fttime_t ssize_t
-#endif
-struct fttimeval {
-	fttime_t tv_sec;
-};
-#define NULL (void *)0
-#endif
-
-#include <dlfcn.h>
 
 /* for repeatability, always return time starting from 1981-02-01 from the
  * first call to time().  This way we can control the aggregator time
  * buckets */
 #define MYEPOCH  349830000
 
-fttime_t (*orig_time)(fttime_t *tloc) = NULL;
-int (*orig_gettimeofday)(struct fttimeval *tp, void *tz) = NULL;
-fttime_t fake_offset = 0;
+static time_t fake_offset = 0;
+time_t faketime(time_t *tloc) {
+	time_t now;
 
-__attribute__((constructor)) void init(void) {
-	orig_time = dlsym(RTLD_NEXT, "time");
-	orig_gettimeofday = dlsym(RTLD_NEXT, "gettimeofday");
-}
-
-fttime_t time(fttime_t *tloc) {
-	fttime_t now;
-
-	(void)orig_time(&now);
+	(void)time(&now);
 
 	if (fake_offset == 0)
 		fake_offset = now - MYEPOCH;
@@ -77,18 +45,19 @@ fttime_t time(fttime_t *tloc) {
 	return now;
 }
 
-int gettimeofday(struct fttimeval *tp, void *tzp) {
+int fakegettimeofday(struct timeval *tp, void *tzp) {
 	/* some platforms, like Darwin and Solaris, have an implementation
 	 * of gettimeofday that does not call time(), others, like glibc do
 	 * which means we need to deal with that here */
-	fttime_t now;
+	time_t now;
 
-	int ret = orig_gettimeofday(tp, tzp);
+	int ret = gettimeofday(tp, tzp);
 	if (ret != 0)
 		return ret;
 
 	/* setup clock offset */
-	now = time(NULL);
+	if (fake_offset == 0)
+		now = time(NULL);
 	now += fake_offset;
 
 	if (now >= tp->tv_sec)

faketime.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2013-2024 Fabian Groffen
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef HAVE_FAKETIME_H
+#define HAVE_FAKETIME_H 1
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <time.h>
+#include <sys/time.h>
+
+time_t faketime(time_t *tloc);
+int fakegettimeofday(struct timeval *tp, void *tx);
+
+#endif

test/run-test.sh

@@ -15,7 +15,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-EXEC=../relay
+EXEC=../relaytest
 SMEXEC=../sendmetric
 EFLAGS="-Htest.hostname -t"
 DIFF="diff -Nu"
@@ -25,10 +25,6 @@ CNFCLN=( sed -e '/^configuration:/,/^parsed configuration follows:/d'
              -e 's/^\[[0-9][0-9\-]* [0-9][0-9:]*\] //'
              -e 's/_stub_[0-9a-fx][0-9a-fx]*__/_stub_0xc0d3__/')
 
-export DYLD_FORCE_FLAT_NAMESPACE=1
-export DYLD_INSERT_LIBRARIES=../.libs/libfaketime.dylib
-export LD_PRELOAD=../.libs/libfaketime.so
-
 buftest_generate() {
   i=1
   end=2000