wireguard-go-bridge: use boottime instead of monotonic

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

wireguard-go-bridge/Makefile

@@ -26,6 +26,26 @@ export CGO_ENABLED := 1
 build: $(DESTDIR)/libwg-go.a
 version-header: $(DESTDIR)/wireguard-go-version.h
 
+GOBUILDARCH := $(GOARCH_$(shell uname -m))
+GOBUILDOS := $(shell uname -s | tr '[:upper:]' '[:lower:]')
+GOBUILDVERSION := 1.11.1
+GOBUILDTARBALL := https://dl.google.com/go/go$(GOBUILDVERSION).$(GOBUILDOS)-$(GOBUILDARCH).tar.gz
+GOBUILDVERSION_NEEDED := go version go$(GOBUILDVERSION) $(GOBUILDOS)/$(GOBUILDARCH)
+export GOROOT := $(BUILDDIR)/goroot
+export GOPATH := $(BUILDDIR)/gopath
+export PATH := $(GOROOT)/bin:$(PATH)
+GOBUILDVERSION_CURRENT := $(shell $(GOROOT)/bin/go version 2>/dev/null)
+ifneq ($(GOBUILDVERSION_NEEDED),$(GOBUILDVERSION_CURRENT))
+$(shell rm -f $(GOROOT)/bin/go)
+endif
+$(GOROOT)/bin/go:
+	rm -rf "$(GOROOT)"
+	mkdir -p "$(GOROOT)"
+	curl "$(GOBUILDTARBALL)" | tar -C "$(GOROOT)" --strip-components=1 -xzf - || { rm -rf "$(GOROOT)"; exit 1; }
+	patch -p1 -f -N -r- -d "$(GOROOT)" < goruntime-boottime-over-monotonic.diff || { rm -rf "$(GOROOT)"; exit 1; }
+
+$(shell test "$$(cat "$(BUILDDIR)/.gobuildversion" 2>/dev/null)" = "$(GOBUILDVERSION_CURRENT)" || rm -f "$(DESTDIR)/libwg-go.a")
+
 define copy-src-to-build
 $(subst $(1),$(BUILDDIR)/,$(2)): $(2)
 	@mkdir -vp "$$(dir $$@)"
@@ -36,20 +56,19 @@ endef
 $(foreach FILE,$(UPSTREAM_FILES),$(eval $(call copy-src-to-build,../wireguard-go/,$(FILE))))
 $(foreach FILE,$(DOWNSTREAM_FILES),$(eval $(call copy-src-to-build,src/,$(FILE))))
 
-$(BUILDDIR)/.prepared:
+$(BUILDDIR)/.prepared: $(GOROOT)/bin/go
-	@touch "$@"
+	cd "$(BUILDDIR)" || exit $$?; $(foreach ARCH,$(ARCHS),CC="$(CC_$(ARCH))" CGO_CFLAGS="$(CGO_FLAGS_$(ARCH))" CGO_LDFLAGS="$(CGO_FLAGS_$(ARCH))" GOARCH="$(GOARCH_$(ARCH))" go get -tags ios || { ret=$$?; chmod -fR +w "$(GOPATH)/pkg/mod"; rm -rf "$(GOPATH)/pkg/mod"; exit $$ret; };)
+	chmod -fR +w "$(GOPATH)/pkg/mod"
+	touch "$@"
 
 define libwg-go-a
 $(BUILDDIR)/libwg-go-$(1).a: $(BUILDDIR)/.prepared
 	cd "$(BUILDDIR)" || exit $$$$?; \
-	export CC="$(CC_$(1))" \
+	CC="$(CC_$(1))" \
 	CGO_CFLAGS="$(CGO_FLAGS_$(1))" \
 	CGO_LDFLAGS="$(CGO_FLAGS_$(1))" \
 	GOARCH="$(GOARCH_$(1))" \
-	GOPATH="$(BUILDDIR)/gopath"; \
+	go build -tags ios -v -o "$(BUILDDIR)/libwg-go-$(1).a" -buildmode c-archive && go version > "$(BUILDDIR)/.gobuildversion"; \
-	go get -tags ios || { ret=$$$$?; chmod -fR +w "$(BUILDDIR)/gopath/pkg/mod"; rm -rf "$(BUILDDIR)/gopath/pkg/mod"; exit $$$$ret; }; \
-	chmod -fR +w "$(BUILDDIR)/gopath/pkg/mod"; \
-	go build -tags ios -v -o "$(BUILDDIR)/libwg-go-$(1).a" -buildmode c-archive; \
 	ret=$$$$?; \
 	rm -f "$(BUILDDIR)/libwg-go-$(1).h"; \
 	exit $$$$ret

wireguard-go-bridge/goruntime-boottime-over-monotonic.diff

@@ -0,0 +1,60 @@
+diff -r -u go/src/runtime/sys_darwin_386.s go-modified/src/runtime/sys_darwin_386.s
+--- go/src/runtime/sys_darwin_386.s	2018-10-01 23:02:54.000000000 +0200
++++ go-modified/src/runtime/sys_darwin_386.s	2018-11-01 23:18:04.383055355 +0100
+@@ -184,7 +184,7 @@
+ 	PUSHL	BP
+ 	MOVL	SP, BP
+ 	SUBL	$8+(machTimebaseInfo__size+15)/16*16, SP
+-	CALL	libc_mach_absolute_time(SB)
++	CALL	libc_mach_continuous_time(SB)
+ 	MOVL	16+(machTimebaseInfo__size+15)/16*16(SP), CX
+ 	MOVL	AX, 0(CX)
+ 	MOVL	DX, 4(CX)
+diff -r -u go/src/runtime/sys_darwin_amd64.s go-modified/src/runtime/sys_darwin_amd64.s
+--- go/src/runtime/sys_darwin_amd64.s	2018-10-01 23:02:54.000000000 +0200
++++ go-modified/src/runtime/sys_darwin_amd64.s	2018-11-01 23:18:04.382055360 +0100
+@@ -85,7 +85,7 @@
+ 	PUSHQ	BP
+ 	MOVQ	SP, BP
+ 	MOVQ	DI, BX
+-	CALL	libc_mach_absolute_time(SB)
++	CALL	libc_mach_continuous_time(SB)
+ 	MOVQ	AX, 0(BX)
+ 	MOVL	timebase<>+machTimebaseInfo_numer(SB), SI
+ 	MOVL	timebase<>+machTimebaseInfo_denom(SB), DI // atomic read
+diff -r -u go/src/runtime/sys_darwin_arm64.s go-modified/src/runtime/sys_darwin_arm64.s
+--- go/src/runtime/sys_darwin_arm64.s	2018-10-01 23:02:54.000000000 +0200
++++ go-modified/src/runtime/sys_darwin_arm64.s	2018-11-01 23:18:04.380055369 +0100
+@@ -110,7 +110,7 @@
+ 
+ TEXT runtime·nanotime_trampoline(SB),NOSPLIT,$40
+ 	MOVD	R0, R19
+-	BL	libc_mach_absolute_time(SB)
++	BL	libc_mach_continuous_time(SB)
+ 	MOVD	R0, 0(R19)
+ 	MOVW	timebase<>+machTimebaseInfo_numer(SB), R20
+ 	MOVD	$timebase<>+machTimebaseInfo_denom(SB), R21
+diff -r -u go/src/runtime/sys_darwin_arm.s go-modified/src/runtime/sys_darwin_arm.s
+--- go/src/runtime/sys_darwin_arm.s	2018-10-01 23:02:54.000000000 +0200
++++ go-modified/src/runtime/sys_darwin_arm.s	2018-11-01 23:18:04.381055364 +0100
+@@ -118,7 +118,7 @@
+ 
+ TEXT runtime·nanotime_trampoline(SB),NOSPLIT,$0
+ 	MOVW	R0, R8
+-	BL	libc_mach_absolute_time(SB)
++	BL	libc_mach_continuous_time(SB)
+ 	MOVW	R0, 0(R8)
+ 	MOVW	R1, 4(R8)
+ 	MOVW	timebase<>+machTimebaseInfo_numer(SB), R6
+diff -r -u go/src/runtime/sys_darwin.go go-modified/src/runtime/sys_darwin.go
+--- go/src/runtime/sys_darwin.go	2018-10-01 23:02:54.000000000 +0200
++++ go-modified/src/runtime/sys_darwin.go	2018-11-01 23:18:04.384055350 +0100
+@@ -348,7 +348,7 @@
+ //go:cgo_import_dynamic libc_usleep usleep "/usr/lib/libSystem.B.dylib"
+ 
+ //go:cgo_import_dynamic libc_mach_timebase_info mach_timebase_info "/usr/lib/libSystem.B.dylib"
+-//go:cgo_import_dynamic libc_mach_absolute_time mach_absolute_time "/usr/lib/libSystem.B.dylib"
++//go:cgo_import_dynamic libc_mach_continuous_time mach_continuous_time "/usr/lib/libSystem.B.dylib"
+ //go:cgo_import_dynamic libc_gettimeofday gettimeofday "/usr/lib/libSystem.B.dylib"
+ //go:cgo_import_dynamic libc_sigaction sigaction "/usr/lib/libSystem.B.dylib"
+ //go:cgo_import_dynamic libc_pthread_sigmask pthread_sigmask "/usr/lib/libSystem.B.dylib"