tools: bpftool: add support for loading programs for offload

Extend the bpftool prog load command to also accept "dev"
parameter, which will allow us to load programs onto devices.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/bpf/bpftool/Documentation/bpftool-prog.rst

@@ -24,7 +24,7 @@ MAP COMMANDS
 |	**bpftool** **prog dump xlated** *PROG* [{**file** *FILE* | **opcodes** | **visual**}]
 |	**bpftool** **prog dump jited**  *PROG* [{**file** *FILE* | **opcodes**}]
 |	**bpftool** **prog pin** *PROG* *FILE*
-|	**bpftool** **prog load** *OBJ* *FILE*
+|	**bpftool** **prog load** *OBJ* *FILE* [**dev** *NAME*]
 |	**bpftool** **prog help**
 |
 |	*PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* }
@@ -64,8 +64,10 @@ DESCRIPTION
 
 		  Note: *FILE* must be located in *bpffs* mount.
 
-	**bpftool prog load** *OBJ* *FILE*
+	**bpftool prog load** *OBJ* *FILE* [**dev** *NAME*]
 		  Load bpf program from binary *OBJ* and pin as *FILE*.
+		  If **dev** *NAME* is specified program will be loaded onto
+		  given networking device (offload).
 
 		  Note: *FILE* must be located in *bpffs* mount.
 

tools/bpf/bpftool/bash-completion/bpftool

@@ -99,6 +99,12 @@ _bpftool_get_prog_tags()
         command sed -n 's/.*"tag": "\(.*\)",$/\1/p' )" -- "$cur" ) )
 }
 
+_sysfs_get_netdevs()
+{
+    COMPREPLY+=( $( compgen -W "$( ls /sys/class/net 2>/dev/null )" -- \
+        "$cur" ) )
+}
+
 # For bpftool map update: retrieve type of the map to update.
 _bpftool_map_update_map_type()
 {
@@ -262,8 +268,21 @@ _bpftool()
                     return 0
                     ;;
                 load)
-                    _filedir
-                    return 0
+                    if [[ ${#words[@]} -lt 6 ]]; then
+                        _filedir
+                        return 0
+                    fi
+
+                    case $prev in
+                        dev)
+                            _sysfs_get_netdevs
+                            return 0
+                            ;;
+                        *)
+                            _bpftool_once_attr 'dev'
+                            return 0
+                            ;;
+                    esac
                     ;;
                 *)
                     [[ $prev == $object ]] && \

tools/bpf/bpftool/prog.c

@@ -39,6 +39,7 @@
 #include <string.h>
 #include <time.h>
 #include <unistd.h>
+#include <net/if.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 
@@ -681,6 +682,9 @@ static int do_pin(int argc, char **argv)
 
 static int do_load(int argc, char **argv)
 {
+	struct bpf_prog_load_attr attr = {
+		.prog_type	= BPF_PROG_TYPE_UNSPEC,
+	};
 	const char *objfile, *pinfile;
 	struct bpf_object *obj;
 	int prog_fd;
@@ -690,7 +694,34 @@ static int do_load(int argc, char **argv)
 	objfile = GET_ARG();
 	pinfile = GET_ARG();
 
-	if (bpf_prog_load(objfile, BPF_PROG_TYPE_UNSPEC, &obj, &prog_fd)) {
+	while (argc) {
+		if (is_prefix(*argv, "dev")) {
+			NEXT_ARG();
+
+			if (attr.ifindex) {
+				p_err("offload device already specified");
+				return -1;
+			}
+			if (!REQ_ARGS(1))
+				return -1;
+
+			attr.ifindex = if_nametoindex(*argv);
+			if (!attr.ifindex) {
+				p_err("unrecognized netdevice '%s': %s",
+				      *argv, strerror(errno));
+				return -1;
+			}
+			NEXT_ARG();
+		} else {
+			p_err("expected no more arguments or 'dev', got: '%s'?",
+			      *argv);
+			return -1;
+		}
+	}
+
+	attr.file = objfile;
+
+	if (bpf_prog_load_xattr(&attr, &obj, &prog_fd)) {
 		p_err("failed to load program");
 		return -1;
 	}
@@ -722,7 +753,7 @@ static int do_help(int argc, char **argv)
 		"       %s %s dump xlated PROG [{ file FILE | opcodes | visual }]\n"
 		"       %s %s dump jited  PROG [{ file FILE | opcodes }]\n"
 		"       %s %s pin   PROG FILE\n"
-		"       %s %s load  OBJ  FILE\n"
+		"       %s %s load  OBJ  FILE [dev NAME]\n"
 		"       %s %s help\n"
 		"\n"
 		"       " HELP_SPEC_PROGRAM "\n"