[CRIU] [PATCH 2/4] protobuf: Start switching our image entries to Google's protobuf

[Cyrill Gorcunov]

A short story -- there were a long conversation on which format should
be used to keep checkpointed data on disk image. We ended up in using
Google's Protocol Buffers (see https://developers.google.com/protocol-buffers/
for detailed description). Thus image entries should be convered to PB.

But before anything else we need a scaffold, ie .proto files which declare
entries on disk.

Instead of squashing everything in one commit we introduce only a few
types needed for further work. In particular

 - message fdinfo_entry

        This message maps old fdinfo_entry structure

 - message fown_t

        This message maps old fown_t, which is embedded
        in a number of another messages

 - message reg_file_entry

        This message maps old reg_file_entry structure

Note that there is no real use of this facility in our code yet.

Build note: one should have protobuf and protobuf-c installed to be able
to build crtools.

 - http://code.google.com/p/protobuf/
 - http://code.google.com/p/protobuf-c/

Inspired-by: Kinsbursky Stanislav <skinsbursky at openvz.org>
Inspired-by: Pavel Emelianov <xemul at parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
---
 Makefile               |   14 +++++++++---
 protobuf/Makefile      |   53 ++++++++++++++++++++++++++++++++++++++++++++++++
 protobuf/fdinfo.proto  |    6 +++++
 protobuf/fown.proto    |    7 ++++++
 protobuf/regfile.proto |   10 +++++++++
 5 files changed, 86 insertions(+), 4 deletions(-)
 create mode 100644 protobuf/Makefile
 create mode 100644 protobuf/fdinfo.proto
 create mode 100644 protobuf/fown.proto
 create mode 100644 protobuf/regfile.proto

diff --git a/Makefile b/Makefile
index 81c9ca8..db2e6f7 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@ include Makefile.inc
 CFLAGS		+= -I./include
 CFLAGS		+= -O0 -ggdb3
 
-LIBS		+= -lrt -lpthread
+LIBS		+= -lrt -lpthread -lprotobuf-c
 
 DEFINES		+= -D_FILE_OFFSET_BITS=64
 DEFINES		+= -D_GNU_SOURCE
@@ -60,6 +60,8 @@ OBJS		+= mount.o
 OBJS		+= inotify.o
 OBJS		+= pstree.o
 
+PROTOBUF-LIB	:= protobuf/protobuf-lib.o
+
 DEPS		:= $(patsubst %.o,%.d,$(OBJS))
 
 MAKEFLAGS	+= --no-print-directory
@@ -68,13 +70,16 @@ include Makefile.syscall
 include Makefile.pie
 
 .PHONY: all test-legacy zdtm test rebuild clean distclean tags cscope	\
-	docs help pie
+	docs help pie protobuf
 
-all: pie
+all: protobuf pie
 	$(Q) $(MAKE) $(PROGRAM)
 
 pie: $(PIE-GEN)
 
+protobuf:
+	$(Q) $(MAKE) -C protobuf/ all
+
 %.o: %.c
 	$(E) "  CC      " $@
 	$(Q) $(CC) -c $(CFLAGS) $< -o $@
@@ -91,7 +96,7 @@ pie: $(PIE-GEN)
 	$(E) "  DEP     " $@
 	$(Q) $(CC) -M -MT $@ -MT $(patsubst %.d,%.o,$@) $(CFLAGS) $< -o $@
 
-$(PROGRAM): $(OBJS) $(SYS-OBJ)
+$(PROGRAM): $(OBJS) $(SYS-OBJ) $(PROTOBUF-LIB)
 	$(E) "  LINK    " $@
 	$(Q) $(CC) $(CFLAGS) $^ $(LIBS) -o $@
 
@@ -120,6 +125,7 @@ clean: cleanpie cleansyscall
 	$(Q) $(RM) -f ./*.bin
 	$(Q) $(RM) -f ./$(PROGRAM)
 	$(Q) $(RM) -rf ./test/dump/
+	$(Q) $(MAKE) -C protobuf/ clean
 	$(Q) $(MAKE) -C test/legacy clean
 	$(Q) $(MAKE) -C test/zdtm cleandep
 	$(Q) $(MAKE) -C test/zdtm clean
diff --git a/protobuf/Makefile b/protobuf/Makefile
new file mode 100644
index 0000000..b8d46b0
--- /dev/null
+++ b/protobuf/Makefile
@@ -0,0 +1,53 @@
+-include ../Makefile.inc
+
+CFLAGS		+= -I./include
+CFLAGS		+= -O0 -ggdb3
+
+DEFINES		+= -D_FILE_OFFSET_BITS=64
+DEFINES		+= -D_GNU_SOURCE
+
+ifneq ($(WERROR),0)
+	WARNINGS += -Werror
+endif
+
+ifeq ($(DEBUG),1)
+	DEFINES += -DCR_DEBUG
+endif
+
+WARNINGS	+= -Wall
+CFLAGS		+= $(WARNINGS) $(DEFINES)
+
+LIBRARY		:= protobuf-lib.o
+
+PROTO_FILES	+= fown.proto
+PROTO_FILES	+= fdinfo.proto
+PROTO_FILES	+= regfile.proto
+
+HDRS	:= $(patsubst %.proto,%.pb-c.h,$(PROTO_FILES))
+SRCS	:= $(patsubst %.proto,%.pb-c.c,$(PROTO_FILES))
+OBJS	:= $(patsubst %.c,%.o,$(SRCS))
+
+.DEFAULT_GOAL	:= all
+
+%.pb-c.c: %.proto
+	$(E) "  PROTOBUF "$@
+	$(Q) protoc-c --c_out=./ $<
+
+%.o: %.c
+	$(E) "  CC       "$@
+	$(Q) $(CC) -c $(CFLAGS) $< -o $@
+
+.SECONDARY:
+
+$(LIBRARY): $(OBJS)
+	$(E) "  LINK     "$@
+	$(Q) ld -r -o $@ $(OBJS)
+
+.PHONY: all clean
+
+all: $(LIBRARY)
+
+clean:
+	$(E) "  CLEAN PROTOBUF"
+	$(Q) rm -f $(SRCS) $(HDRS) $(OBJS) $(LIBRARY)
+
diff --git a/protobuf/fdinfo.proto b/protobuf/fdinfo.proto
new file mode 100644
index 0000000..3b4a57c
--- /dev/null
+++ b/protobuf/fdinfo.proto
@@ -0,0 +1,6 @@
+message fdinfo_entry {
+	required uint32	id	= 1;
+	required uint32	flags	= 2;
+	required uint32	type	= 3;
+	required uint32	fd	= 4;
+}
diff --git a/protobuf/fown.proto b/protobuf/fown.proto
new file mode 100644
index 0000000..5f83a8d
--- /dev/null
+++ b/protobuf/fown.proto
@@ -0,0 +1,7 @@
+message fown_t {
+	required uint32	uid		= 1;
+	required uint32	euid		= 2;
+	required uint32	signum		= 3;
+	required uint32	pid_type	= 4;
+	required uint32	pid		= 5;
+}
diff --git a/protobuf/regfile.proto b/protobuf/regfile.proto
new file mode 100644
index 0000000..7efac6c
--- /dev/null
+++ b/protobuf/regfile.proto
@@ -0,0 +1,10 @@
+import "fown.proto";
+
+message reg_file_entry {
+	required uint32		id	= 1;
+	required uint32		flags	= 2;
+	required uint64		pos	= 3;
+	required uint32		len	= 4;
+	required fown_t		fown	= 5;
+	optional string		name	= 6;
+}
-- 
1.7.7.6