Embedding libxdp

.gitmodules

@@ -2,3 +2,6 @@
 	path = lib/libbpf
 	url = https://github.com/xdp-project/libbpf.git
 	ignore = dirty
+[submodule "lib/xdp-tools"]
+	path = lib/xdp-tools
+	url = https://github.com/xdp-project/xdp-tools

configure

@@ -11,6 +11,8 @@ CONFIG=".${CONFIG}.tmp"
 TMPDIR=$(mktemp -d config.XXXXXX)
 trap 'status=$?; rm -rf $TMPDIR; rm -f $CONFIG; exit $status' EXIT HUP INT QUIT TERM
 
+SUBMODULE_LIBBPF=0
+
 check_toolchain()
 {
     local clang_version
@@ -123,12 +125,10 @@ EOF
     fi
 
     echo submodule
+    SUBMODULE_LIBBPF=1
     echo "SYSTEM_LIBBPF:=n" >> $CONFIG
-    echo 'CFLAGS += -I$(LIB_DIR)/libbpf-install/usr/include' >>$CONFIG
-    echo 'BPF_CFLAGS += -I$(LIB_DIR)/libbpf-install/usr/include' >>$CONFIG
-    echo 'LDFLAGS += -L$(LIB_DIR)/libbpf/src' >>$CONFIG
     echo 'LDLIBS += -l:libbpf.a' >>$CONFIG
-    echo 'OBJECT_LIBBPF = $(LIB_DIR)/libbpf/src/libbpf.a' >>$CONFIG
+    echo 'OBJECT_LIBBPF = $(LIB_DIR)/install/lib/libbpf.a' >>$CONFIG
     if ! [ -d "lib/libbpf/src" ] && [ -f ".gitmodules" ] && [ -e ".git" ]; then
         git submodule init && git submodule update
     fi
@@ -173,6 +173,39 @@ EOF
     fi
 }
 
+check_libxdp()
+{
+    if [ "${FORCE_SUBMODULE_LIBXDP:-0}" -ne "1" ] && ${PKG_CONFIG} libxdp --exists; then
+
+        LIBXDP_CFLAGS=$(${PKG_CONFIG} libxdp --cflags)
+        LIBXDP_LDLIBS=$(${PKG_CONFIG} libxdp --libs)
+        echo "SYSTEM_LIBXDP:=y" >>$CONFIG
+        echo 'CFLAGS += ' $LIBXDP_CFLAGS >> $CONFIG
+        echo 'LDLIBS += ' $LIBXDP_LDLIBS >>$CONFIG
+        echo 'OBJECT_LIBXDP = ' >>$CONFIG
+        echo system
+
+        return 0
+    fi
+
+    echo submodule
+    echo "SYSTEM_LIBXDP:=n" >> $CONFIG
+    if [ "$SUBMODULE_LIBBPF" -eq "1" ]; then
+        echo "Configuring libxdp to use our libbpf submodule"
+        (export LIBBPF_DIR="$(readlink -m lib/libbpf)" LIBBPF_INCLUDE_DIR="$(readlink -m lib/install/include)";
+         cd lib/xdp-tools; ./configure)
+    else
+        echo "Configuring libxdp without our libbpf"
+        (cd lib/xdp-tools; ./configure)
+    fi
+    echo 'LDFLAGS += -L$(LIB_DIR)/install/lib' >>$CONFIG
+    echo 'LDLIBS += -l:libxdp.a' >>$CONFIG
+    echo 'OBJECT_LIBXDP = $(LIB_DIR)/install/lib/libxdp.a' >>$CONFIG
+    if ! [ -d "lib/xdp-tools/lib" ] && [ -f ".gitmodules" ] && [ -e ".git" ]; then
+        git submodule init && git submodule update
+    fi
+}
+
 quiet_config()
 {
     cat <<EOF
@@ -211,6 +244,8 @@ check_toolchain
 
 echo -n "libbpf support: "
 check_libbpf
+echo -n "libxdp support: "
+check_libxdp
 
 check_bpf_use_errno
 

lib/Makefile

@@ -2,26 +2,31 @@
 LIBBPF_CFLAGS:=$(if $(CFLAGS),$(CFLAGS),-g -O2 -Werror -Wall) -fPIC
 
 LIB_DIR = .
+LIB_INSTALL := $(LIB_DIR)/install
 include defines.mk
 
-SUBDIRS=
+SUBDIRS=util
 
-all: $(OBJECT_LIBBPF)
+all: $(OBJECT_LIBBPF) $(OBJECT_LIBXDP)
 	@set -e; \
 	for i in $(SUBDIRS); \
 	do echo; echo "  $$i"; $(MAKE) -C $$i; done
 
 .PHONY: clean
-clean: libbpf_clean
+clean: libbpf_clean libxdp_clean
 	@for i in $(SUBDIRS); \
 	do $(MAKE) -C $$i clean; done
+	$(Q)find $(LIB_INSTALL) -type f -not -name .gitignore -delete
+	$(Q)find $(LIB_INSTALL) -type d -empty -delete
 
 install:
 	install -m 0755 -d $(DESTDIR)$(HDRDIR)
 	$(MAKE) -C libxdp install
 	$(MAKE) -C testing install
 
+
 libbpf: $(OBJECT_LIBBPF)
+libxdp: libbpf $(OBJECT_LIBXDP)
 
 # Handle libbpf as git submodule
 ifeq ($(SYSTEM_LIBBPF),n)
@@ -31,21 +36,44 @@ endif
 
 # Detect submodule libbpf source file changes
 LIBBPF_SOURCES := $(wildcard libbpf/src/*.[ch])
-LIBBPF_INSTALL := libbpf-install
-INSTDIR=../../$(LIBBPF_INSTALL)
 
-.PHONY: libbpf_clean
-libbpf/src/libbpf.a: $(LIBBPF_SOURCES)
+$(LIB_INSTALL)/lib/libbpf.a: $(LIBBPF_SOURCES)
 	@echo ; echo "  libbpf"
 	$(QUIET_CC)$(MAKE) -C libbpf/src CFLAGS="$(LIBBPF_CFLAGS)" $P
-	$(QUIET_INSTALL)$(MAKE) -C libbpf/src DESTDIR=$(INSTDIR) install_headers $P
+	$(QUIET_INSTALL)$(MAKE) -C libbpf/src DESTDIR=../../$(LIB_INSTALL) PREFIX= install_headers $P
+	$(Q)cp -fp libbpf/src/libbpf.a install/lib/
 
+.PHONY: libbpf_clean
 libbpf_clean:
 	$(Q)$(MAKE) -C libbpf/src clean $P
-	$(Q)$(RM) -r $(LIBBPF_INSTALL)
 
 else
 
 libbpf_clean:
 	@echo -n
 endif
+
+# Handle libbpf as git submodule
+ifeq ($(SYSTEM_LIBXDP),n)
+ifeq ($(VERBOSE),0)
+P:= >/dev/null
+endif
+
+# Detect submodule libbpf source file changes
+LIBXDP_SOURCES := $(wildcard xdp-tools/lib/libxdp/libxdp*.[ch]) xdp-tools/lib/libxdp/xsk.c
+
+
+$(LIB_INSTALL)/lib/libxdp.a: $(LIBXDP_SOURCES)
+	@echo ; echo "  libxdp"
+	$(QUIET_CC)$(MAKE) -C xdp-tools BUILD_STATIC_ONLY=1 libxdp  $P
+	$(QUIET_INSTALL)$(MAKE) -C xdp-tools DESTDIR=../../../$(LIB_INSTALL) PREFIX= BUILD_STATIC_ONLY=1 libxdp_install $P
+
+.PHONY: libxdp_clean
+libxdp_clean:
+	$(Q)$(MAKE) -C xdp-tools clean $P
+
+else
+
+libxdp_clean:
+	@echo -n
+endif

lib/common.mk

@@ -47,8 +47,9 @@ BPF_CFLAGS += -D__TARGET_ARCH_$(ARCH)
 # BPF-prog kern and userspace shares struct via header file:
 KERN_USER_H ?= $(wildcard common_kern_user.h)
 
-CFLAGS += -I$(INCLUDE_DIR) -I$(HEADER_DIR) -I$(LIB_DIR)/util $(EXTRA_CFLAGS)
-BPF_CFLAGS += -I$(INCLUDE_DIR) -I$(HEADER_DIR) $(EXTRA_CFLAGS)
+CFLAGS += -I$(INCLUDE_DIR) -I$(HEADER_DIR) -I$(LIB_DIR)/util -I$(LIB_DIR)/install/include $(EXTRA_CFLAGS)
+BPF_CFLAGS += -I$(INCLUDE_DIR) -I$(HEADER_DIR) -I$(LIB_DIR)/install/include $(EXTRA_CFLAGS)
+LDFLAGS += -L$(LIB_DIR)/install/lib
 
 BPF_HEADERS := $(wildcard $(HEADER_DIR)/*/*.h) $(wildcard $(INCLUDE_DIR)/*/*.h)
 
@@ -61,6 +62,9 @@ clean::
 $(OBJECT_LIBBPF): $(LIBBPF_SOURCES)
 	$(Q)$(MAKE) -C $(LIB_DIR) libbpf
 
+$(OBJECT_LIBXDP): $(LIBXDP_SOURCES)
+	$(Q)$(MAKE) -C $(LIB_DIR) libxdp
+
 $(CONFIGMK):
 	$(Q)$(MAKE) -C $(LIB_DIR)/.. config.mk
 

lib/install/.gitignore

@@ -0,0 +1,4 @@
+*
+!.gitignore
+!include
+!lib

lib/install/include/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

lib/install/lib/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

lib/util/Makefile

@@ -0,0 +1,18 @@
+include util.mk
+
+LIB_DIR ?= ..
+
+include $(LIB_DIR)/defines.mk
+
+all: $(UTIL_OBJS)
+
+# Create expansions for dependencies
+UTIL_H := ${UTIL_OBJS:.o=.h}
+
+CFLAGS+= -I$(LIB_DIR)/install/include
+
+$(UTIL_OBJS): %.o: %.c $(UTIL_H) $(LIBMK)
+	$(QUIET_CC)$(CC) $(CFLAGS) -Wall -I../../headers -c -o $@ $<
+
+clean:
+	$(Q)rm -f $(UTIL_OBJS)

lib/util/logging.c

@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include <bpf/libbpf.h>
+#include <xdp/libxdp.h>
+
+#define __unused __attribute__((unused))
+#include "logging.h"
+
+static enum logging_print_level log_level = LOG_INFO;
+
+static int print_func(enum logging_print_level level, const char *format,
+		      va_list args)
+{
+	if (level > log_level)
+		return 0;
+
+	return vfprintf(stderr, format, args);
+}
+
+static int libbpf_print_func(enum libbpf_print_level level, const char *format,
+			     va_list args)
+{
+	return print_func(level + 1, format, args);
+}
+
+static int libbpf_silent_func(__unused enum libbpf_print_level level,
+			      __unused const char *format,
+			      __unused va_list args)
+{
+	return 0;
+}
+
+static int libxdp_print_func(enum libxdp_print_level level, const char *format,
+			     va_list args)
+{
+	return print_func(level + 1, format, args);
+}
+
+static int libxdp_silent_func(__unused enum libxdp_print_level level,
+			      __unused const char *format,
+			      __unused va_list args)
+{
+	return 0;
+}
+
+#define __printf(a, b) __attribute__((format(printf, a, b)))
+
+__printf(2, 3) void logging_print(enum logging_print_level level,
+				  const char *format, ...)
+{
+	va_list args;
+
+	va_start(args, format);
+	print_func(level, format, args);
+	va_end(args);
+}
+
+void init_lib_logging(void)
+{
+	libbpf_set_print(libbpf_print_func);
+	libxdp_set_print(libxdp_print_func);
+}
+
+void silence_libbpf_logging(void)
+{
+	if (log_level < LOG_VERBOSE)
+		libbpf_set_print(libbpf_silent_func);
+}
+
+void silence_libxdp_logging(void)
+{
+	if (log_level < LOG_VERBOSE)
+		libxdp_set_print(libxdp_silent_func);
+}
+
+enum logging_print_level set_log_level(enum logging_print_level level)
+{
+	enum logging_print_level old_level = log_level;
+
+	log_level = level;
+	return old_level;
+}
+
+enum logging_print_level increase_log_level(void)
+{
+	if (log_level < LOG_VERBOSE)
+		log_level++;
+	return log_level;
+}

lib/util/logging.h

@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __LOGGING_H
+#define __LOGGING_H
+
+/* This matches the libbpf logging levels, but with an additional VERBOSE level;
+ * we demote all libbpf messages by one level so debug messages only show up on
+ * VERBOSE.
+ */
+enum logging_print_level {
+	LOG_WARN,
+	LOG_INFO,
+	LOG_DEBUG,
+	LOG_VERBOSE,
+};
+
+extern void logging_print(enum logging_print_level level, const char *format,
+			  ...) __attribute__((format(printf, 2, 3)));
+
+#define __pr(level, fmt, ...)                             \
+	do {                                              \
+		logging_print(level, fmt, ##__VA_ARGS__); \
+	} while (0)
+
+#define pr_warn(fmt, ...) __pr(LOG_WARN, fmt, ##__VA_ARGS__)
+#define pr_info(fmt, ...) __pr(LOG_INFO, fmt, ##__VA_ARGS__)
+#define pr_debug(fmt, ...) __pr(LOG_DEBUG, fmt, ##__VA_ARGS__)
+
+void init_lib_logging(void);
+void silence_libbpf_logging(void);
+void silence_libxdp_logging(void);
+enum logging_print_level set_log_level(enum logging_print_level level);
+enum logging_print_level increase_log_level();
+
+#endif

lib/util/util.mk

@@ -1,2 +1,2 @@
 # list of objects in this directory
-UTIL_OBJS := json_writer.o
+UTIL_OBJS := json_writer.o logging.o

nat64-bpf/nat64.c

@@ -20,6 +20,8 @@
 #include <libmnl/libmnl.h>
 #include <linux/rtnetlink.h>
 
+#include "logging.h"
+
 #include "nat64.h"
 #include "nat64_kern.skel.h"
 
@@ -34,6 +36,7 @@ static const struct option long_options[] = {
 	{ "v6-prefix",        required_argument, NULL, '6' }, // v6 prefix to use for nat64
 	{ "v4-prefix",        required_argument, NULL, '4' }, // v4 prefix to use for nat64
 	{ "timeout",          required_argument, NULL, 't' }, // Address mapping timeout interval in s
+	{ "verbose",          required_argument, NULL, 'v' }, // verbose logging
 	{ 0, 0, NULL, 0 }
 };
 
@@ -85,7 +88,7 @@ static int parse_arguments(int argc, char *argv[], struct nat64_user_config *con
 	config->c.v6_prefix.s6_addr[2] = 0xff;
 	config->c.v6_prefix.s6_addr[3] = 0x9b;
 
-	while ((opt = getopt_long(argc, argv, "i:6:4:t:a:hu", long_options,
+	while ((opt = getopt_long(argc, argv, "i:6:4:t:a:huv", long_options,
 				  NULL)) != -1) {
 		switch (opt) {
 		case 'i':
@@ -161,6 +164,9 @@ static int parse_arguments(int argc, char *argv[], struct nat64_user_config *con
 		case 'u':
 			config->unload = true;
 			break;
+		case 'v':
+			increase_log_level();
+			break;
 		default:
 			fprintf(stderr, "Unknown option %s\n", argv[optind]);
 			return -EINVAL;
@@ -362,6 +368,8 @@ int main(int argc, char *argv[])
 	DECLARE_LIBBPF_OPTS(bpf_tc_opts, attach_egress);
 	DECLARE_LIBBPF_OPTS(bpf_tc_opts, attach_ingress);
 
+	init_lib_logging();
+
 	err = parse_arguments(argc, argv, &cfg);
 	if (err)
 		return EXIT_FAILURE;