xdp: more proper building of bpf-kernel.o

.gitignore

@@ -59,6 +59,10 @@ version.h
 # zscanner
 /src/libzscanner/scanner.c
 
+# xdp
+/src/libknot/xdp/bpf-kernel.ll
+!/src/libknot/xdp/Makefile
+
 # Binaries
 /src/kdig
 /src/khost

Knot.files

@@ -3,9 +3,6 @@ src/contrib/base32hex.c
 src/contrib/base32hex.h
 src/contrib/base64.c
 src/contrib/base64.h
-src/contrib/bpf/bpf_endian.h
-src/contrib/bpf/bpf_helpers.h
-src/contrib/bpf/parsing_helpers.h
 src/contrib/ctype.h
 src/contrib/dnstap/convert.c
 src/contrib/dnstap/convert.h
@@ -370,6 +367,9 @@ src/libknot/xdp/af_xdp.h
 src/libknot/xdp/bpf-kernel.c
 src/libknot/xdp/bpf-user.c
 src/libknot/xdp/bpf-user.h
+src/libknot/xdp/bpf/bpf_endian.h
+src/libknot/xdp/bpf/bpf_helpers.h
+src/libknot/xdp/bpf/parsing_helpers.h
 src/libknot/yparser/yparser.c
 src/libknot/yparser/yparser.h
 src/libknot/yparser/ypbody.c

configure.ac

@@ -208,6 +208,11 @@ AS_CASE([$enable_xdp],
 )
 
 AS_IF([test "$enable_xdp" = "yes"],[
+   AC_CHECK_PROG([have_clang],[clang],[yes],[no])
+   AS_IF([test "$have_clang" != "yes"],[AC_MSG_ERROR([clang not available])])
+   AC_CHECK_PROG([have_llc],[llc],[yes],[no])
+   AS_IF([test "$have_llc" != "yes"],[AC_MSG_ERROR([llc not available])])
+
    save_CFLAGS=$CFLAGS
    save_LIBS=$LIBS
    CFLAGS="$CFLAGS $libbpf_CFLAGS"

src/Makefile.am

@@ -19,3 +19,7 @@ include $(srcdir)/libknot/Makefile.inc
 include $(srcdir)/libzscanner/Makefile.inc
 include $(srcdir)/knot/Makefile.inc
 include $(srcdir)/utils/Makefile.inc
+
+if ENABLE_XDP
+SUBDIRS = libknot/xdp
+endif ENABLE_XDP

src/contrib/Makefile.inc

@@ -27,9 +27,6 @@ libcontrib_la_SOURCES = \
 	contrib/base32hex.h			\
 	contrib/base64.c			\
 	contrib/base64.h			\
-	contrib/bpf/bpf_endian.h		\
-	contrib/bpf/bpf_helpers.h		\
-	contrib/bpf/parsing_helpers.h		\
 	contrib/ctype.h				\
 	contrib/dynarray.h			\
 	contrib/files.c				\

src/libknot/Makefile.inc

@@ -81,6 +81,5 @@ libknot_la_SOURCES = \
 if ENABLE_XDP
 libknot_la_SOURCES += \
 	libknot/xdp/af_xdp.c                    \
-        libknot/xdp/bpf-kernel.c                \
         libknot/xdp/bpf-user.c
 endif ENABLE_XDP

src/libknot/xdp/Makefile

+
+all: bpf-kernel.o
+
+bpf-kernel.ll: bpf-kernel.c
+	clang -S -target bpf -Wall -O2 -emit-llvm -c -g -DNDEBUG -o bpf-kernel.ll bpf-kernel.c
+
+bpf-kernel.o: bpf-kernel.ll
+	llc -march=bpf -filetype=obj -o bpf-kernel.o bpf-kernel.ll
+
+clean:
+	rm -f bpf-kernel.ll bpf-kernel.o
+

src/libknot/xdp/bpf-kernel.c

@@ -3,9 +3,10 @@
 #include <linux/if_ether.h>
 #include <linux/ipv6.h>
 #include <linux/udp.h>
-#include "contrib/bpf/bpf_helpers.h"
-#include "contrib/bpf/bpf_endian.h"
-#include "contrib/bpf/parsing_helpers.h"
+
+#include "bpf/bpf_helpers.h"
+#include "bpf/bpf_endian.h"
+#include "bpf/parsing_helpers.h"
 
 /** Assume netdev has no more than 64 queues
  * LATER: it might be better to detect this on startup time (per-device). */

src/libknot/xdp/bpf-user.c

@@ -14,9 +14,10 @@
     along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-#include "contrib/bpf/bpf_endian.h"
 #include "libknot/xdp/bpf-user.h"
 
+#include "libknot/endian.h"
+
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
@@ -146,7 +147,7 @@ int kxsk_socket_start(const struct kxsk_iface *iface, int queue_id,
 	if (err)
 		return err;
 
-	int qid = bpf_htons(listen_port);
+	int qid = htobe16(listen_port);
 	err = bpf_map_update_elem(iface->qidconf_map_fd, &queue_id, &qid, 0);
 	if (err)
 		bpf_map_delete_elem(iface->xsks_map_fd, &queue_id);