Merge branch 'bpftool-flow-dissector'

Stanislav Fomichev says:

====================
v5 changes:
* FILE -> PATH for load/loadall (can be either file or directory now)
* simpler implementation for __bpf_program__pin_name
* removed p_err for REQ_ARGS checks
* parse_atach_detach_args -> parse_attach_detach_args
* for -> while in bpf_object__pin_{programs,maps} recovery

v4 changes:
* addressed another round of comments/style issues from Jakub Kicinski &
  Quentin Monnet (thanks!)
* implemented bpf_object__pin_maps and bpf_object__pin_programs helpers and
  used them in bpf_program__pin
* added new pin_name to bpf_program so bpf_program__pin
  works with sections that contain '/'
* moved *loadall* command implementation into a separate patch
* added patch that implements *pinmaps* to pin maps when doing
  load/loadall

v3 changes:
* (maybe) better cleanup for partial failure in bpf_object__pin
* added special case in bpf_program__pin for programs with single
  instances

v2 changes:
* addressed comments/style issues from Jakub Kicinski & Quentin Monnet
* removed logic that populates jump table
* added cleanup for partial failure in bpf_object__pin

This patch series adds support for loading and attaching flow dissector
programs from the bpftool:

* first patch fixes flow dissector section name in the selftests (so
  libbpf auto-detection works)
* second patch adds proper cleanup to bpf_object__pin, parts of which are now
  being used to attach all flow dissector progs/maps
* third patch adds special case in bpf_program__pin for programs with
  single instances (we don't create <prog>/0 pin anymore, just <prog>)
* forth patch adds pin_name to the bpf_program struct
  which is now used as a pin name in bpf_program__pin et al
* fifth patch adds *loadall* command that pins all programs, not just
  the first one
* sixth patch adds *pinmaps* argument to load/loadall to let users pin
  all maps of the obj file
* seventh patch adds actual flow_dissector support to the bpftool and
  an example
====================

Acked-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

5 files changed, 182 insertions, 96 deletions

diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
index ac4e904b10fb..8db78ed82a71 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -15,7 +15,8 @@ SYNOPSIS
 	*OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-f** | **--bpffs** } }
 
 	*COMMANDS* :=
-	{ **show** | **list** | **dump xlated** | **dump jited** | **pin** | **load** | **help** }
+	{ **show** | **list** | **dump xlated** | **dump jited** | **pin** | **load**
+	| **loadall** | **help** }
 
 MAP COMMANDS
 =============
@@ -24,9 +25,9 @@ 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* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*]
-|       **bpftool** **prog attach** *PROG* *ATTACH_TYPE* *MAP*
-|       **bpftool** **prog detach** *PROG* *ATTACH_TYPE* *MAP*
+|	**bpftool** **prog { load | loadall }** *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*]
+|       **bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*]
+|       **bpftool** **prog detach** *PROG* *ATTACH_TYPE* [*MAP*]
 |	**bpftool** **prog help**
 |
 |	*MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
@@ -39,7 +40,9 @@ MAP COMMANDS
 |		**cgroup/bind4** | **cgroup/bind6** | **cgroup/post_bind4** | **cgroup/post_bind6** |
 |		**cgroup/connect4** | **cgroup/connect6** | **cgroup/sendmsg4** | **cgroup/sendmsg6**
 |	}
-|       *ATTACH_TYPE* := { **msg_verdict** | **skb_verdict** | **skb_parse** }
+|       *ATTACH_TYPE* := {
+|		**msg_verdict** | **skb_verdict** | **skb_parse** | **flow_dissector**
+|	}
 
 
 DESCRIPTION
@@ -79,8 +82,11 @@ DESCRIPTION
 		  contain a dot character ('.'), which is reserved for future
 		  extensions of *bpffs*.
 
-	**bpftool prog load** *OBJ* *FILE* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*]
-		  Load bpf program from binary *OBJ* and pin as *FILE*.
+	**bpftool prog { load | loadall }** *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] [**pinmaps** *MAP_DIR*]
+		  Load bpf program(s) from binary *OBJ* and pin as *PATH*.
+		  **bpftool prog load** pins only the first program from the
+		  *OBJ* as *PATH*. **bpftool prog loadall** pins all programs
+		  from the *OBJ* under *PATH* directory.
 		  **type** is optional, if not specified program type will be
 		  inferred from section names.
 		  By default bpftool will create new maps as declared in the ELF
@@ -92,18 +98,24 @@ DESCRIPTION
 		  use, referring to it by **id** or through a **pinned** file.
 		  If **dev** *NAME* is specified program will be loaded onto
 		  given networking device (offload).
+		  Optional **pinmaps** argument can be provided to pin all
+		  maps under *MAP_DIR* directory.
 
-		  Note: *FILE* must be located in *bpffs* mount. It must not
+		  Note: *PATH* must be located in *bpffs* mount. It must not
 		  contain a dot character ('.'), which is reserved for future
 		  extensions of *bpffs*.
 
-        **bpftool prog attach** *PROG* *ATTACH_TYPE* *MAP*
-                  Attach bpf program *PROG* (with type specified by *ATTACH_TYPE*)
-                  to the map *MAP*.
-
-        **bpftool prog detach** *PROG* *ATTACH_TYPE* *MAP*
-                  Detach bpf program *PROG* (with type specified by *ATTACH_TYPE*)
-                  from the map *MAP*.
+	**bpftool prog attach** *PROG* *ATTACH_TYPE* [*MAP*]
+		  Attach bpf program *PROG* (with type specified by
+		  *ATTACH_TYPE*). Most *ATTACH_TYPEs* require a *MAP*
+		  parameter, with the exception of *flow_dissector* which is
+		  attached to current networking name space.
+
+	**bpftool prog detach** *PROG* *ATTACH_TYPE* [*MAP*]
+		  Detach bpf program *PROG* (with type specified by
+		  *ATTACH_TYPE*). Most *ATTACH_TYPEs* require a *MAP*
+		  parameter, with the exception of *flow_dissector* which is
+		  detached from the current networking name space.
 
 	**bpftool prog help**
 		  Print short help message.
diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool
index 3f78e6404589..45c2db257d2b 100644
--- a/tools/bpf/bpftool/bash-completion/bpftool
+++ b/tools/bpf/bpftool/bash-completion/bpftool
@@ -243,7 +243,7 @@ _bpftool()
     # Completion depends on object and command in use
     case $object in
         prog)
-            if [[ $command != "load" ]]; then
+            if [[ $command != "load" && $command != "loadall" ]]; then
                 case $prev in
                     id)
                         _bpftool_get_prog_ids
@@ -299,7 +299,8 @@ _bpftool()
                     fi
 
                     if [[ ${#words[@]} == 6 ]]; then
-                        COMPREPLY=( $( compgen -W "msg_verdict skb_verdict skb_parse" -- "$cur" ) )
+                        COMPREPLY=( $( compgen -W "msg_verdict skb_verdict \
+                            skb_parse flow_dissector" -- "$cur" ) )
                         return 0
                     fi
 
@@ -309,7 +310,7 @@ _bpftool()
                     fi
                     return 0
                     ;;
-                load)
+                load|loadall)
                     local obj
 
                     if [[ ${#words[@]} -lt 6 ]]; then
@@ -338,7 +339,16 @@ _bpftool()
 
                     case $prev in
                         type)
-                            COMPREPLY=( $( compgen -W "socket kprobe kretprobe classifier action tracepoint raw_tracepoint xdp perf_event cgroup/skb cgroup/sock cgroup/dev lwt_in lwt_out lwt_xmit lwt_seg6local sockops sk_skb sk_msg lirc_mode2 cgroup/bind4 cgroup/bind6 cgroup/connect4 cgroup/connect6 cgroup/sendmsg4 cgroup/sendmsg6 cgroup/post_bind4 cgroup/post_bind6" -- \
+                            COMPREPLY=( $( compgen -W "socket kprobe \
+                                kretprobe classifier flow_dissector \
+                                action tracepoint raw_tracepoint \
+                                xdp perf_event cgroup/skb cgroup/sock \
+                                cgroup/dev lwt_in lwt_out lwt_xmit \
+                                lwt_seg6local sockops sk_skb sk_msg \
+                                lirc_mode2 cgroup/bind4 cgroup/bind6 \
+                                cgroup/connect4 cgroup/connect6 \
+                                cgroup/sendmsg4 cgroup/sendmsg6 \
+                                cgroup/post_bind4 cgroup/post_bind6" -- \
                                                    "$cur" ) )
                             return 0
                             ;;
@@ -346,7 +356,7 @@ _bpftool()
                             _bpftool_get_map_ids
                             return 0
                             ;;
-                        pinned)
+                        pinned|pinmaps)
                             _filedir
                             return 0
                             ;;
@@ -358,6 +368,7 @@ _bpftool()
                             COMPREPLY=( $( compgen -W "map" -- "$cur" ) )
                             _bpftool_once_attr 'type'
                             _bpftool_once_attr 'dev'
+                            _bpftool_once_attr 'pinmaps'
                             return 0
                             ;;
                     esac
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index 1149565be4b1..cb06a5b6e016 100644
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -177,34 +177,23 @@ int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type)
 	return fd;
 }
 
-int do_pin_fd(int fd, const char *name)
+int mount_bpffs_for_pin(const char *name)
 {
 	char err_str[ERR_MAX_LEN];
 	char *file;
 	char *dir;
 	int err = 0;
 
-	err = bpf_obj_pin(fd, name);
-	if (!err)
-		goto out;
-
 	file = malloc(strlen(name) + 1);
 	strcpy(file, name);
 	dir = dirname(file);
 
-	if (errno != EPERM || is_bpffs(dir)) {
-		p_err("can't pin the object (%s): %s", name, strerror(errno));
+	if (is_bpffs(dir))
+		/* nothing to do if already mounted */
 		goto out_free;
-	}
 
-	/* Attempt to mount bpffs, then retry pinning. */
 	err = mnt_bpffs(dir, err_str, ERR_MAX_LEN);
-	if (!err) {
-		err = bpf_obj_pin(fd, name);
-		if (err)
-			p_err("can't pin the object (%s): %s", name,
-			      strerror(errno));
-	} else {
+	if (err) {
 		err_str[ERR_MAX_LEN - 1] = '\0';
 		p_err("can't mount BPF file system to pin the object (%s): %s",
 		      name, err_str);
@@ -212,10 +201,20 @@ int do_pin_fd(int fd, const char *name)
 
 out_free:
 	free(file);
-out:
 	return err;
 }
 
+int do_pin_fd(int fd, const char *name)
+{
+	int err;
+
+	err = mount_bpffs_for_pin(name);
+	if (err)
+		return err;
+
+	return bpf_obj_pin(fd, name);
+}
+
 int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
 {
 	unsigned int id;
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index 14857c273bf6..61d82020af58 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -131,6 +131,7 @@ const char *get_fd_type_name(enum bpf_obj_type type);
 char *get_fdinfo(int fd, const char *key);
 int open_obj_pinned(char *path);
 int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type);
+int mount_bpffs_for_pin(const char *name);
 int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32));
 int do_pin_fd(int fd, const char *name);
 
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index b9b84553bec4..5ff5544596e7 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -81,6 +81,7 @@ static const char * const attach_type_strings[] = {
 	[BPF_SK_SKB_STREAM_PARSER] = "stream_parser",
 	[BPF_SK_SKB_STREAM_VERDICT] = "stream_verdict",
 	[BPF_SK_MSG_VERDICT] = "msg_verdict",
+	[BPF_FLOW_DISSECTOR] = "flow_dissector",
 	[__MAX_BPF_ATTACH_TYPE] = NULL,
 };
 
@@ -721,30 +722,49 @@ int map_replace_compar(const void *p1, const void *p2)
 	return a->idx - b->idx;
 }
 
-static int do_attach(int argc, char **argv)
+static int parse_attach_detach_args(int argc, char **argv, int *progfd,
+				    enum bpf_attach_type *attach_type,
+				    int *mapfd)
 {
-	enum bpf_attach_type attach_type;
-	int err, mapfd, progfd;
-
-	if (!REQ_ARGS(5)) {
-		p_err("too few parameters for map attach");
+	if (!REQ_ARGS(3))
 		return -EINVAL;
-	}
 
-	progfd = prog_parse_fd(&argc, &argv);
-	if (progfd < 0)
-		return progfd;
+	*progfd = prog_parse_fd(&argc, &argv);
+	if (*progfd < 0)
+		return *progfd;
 
-	attach_type = parse_attach_type(*argv);
-	if (attach_type == __MAX_BPF_ATTACH_TYPE) {
-		p_err("invalid attach type");
+	*attach_type = parse_attach_type(*argv);
+	if (*attach_type == __MAX_BPF_ATTACH_TYPE) {
+		p_err("invalid attach/detach type");
 		return -EINVAL;
 	}
+
+	if (*attach_type == BPF_FLOW_DISSECTOR) {
+		*mapfd = -1;
+		return 0;
+	}
+
 	NEXT_ARG();
+	if (!REQ_ARGS(2))
+		return -EINVAL;
+
+	*mapfd = map_parse_fd(&argc, &argv);
+	if (*mapfd < 0)
+		return *mapfd;
+
+	return 0;
+}
 
-	mapfd = map_parse_fd(&argc, &argv);
-	if (mapfd < 0)
-		return mapfd;
+static int do_attach(int argc, char **argv)
+{
+	enum bpf_attach_type attach_type;
+	int err, progfd;
+	int mapfd;
+
+	err = parse_attach_detach_args(argc, argv,
+				       &progfd, &attach_type, &mapfd);
+	if (err)
+		return err;
 
 	err = bpf_prog_attach(progfd, mapfd, attach_type, 0);
 	if (err) {
@@ -760,27 +780,13 @@ static int do_attach(int argc, char **argv)
 static int do_detach(int argc, char **argv)
 {
 	enum bpf_attach_type attach_type;
-	int err, mapfd, progfd;
-
-	if (!REQ_ARGS(5)) {
-		p_err("too few parameters for map detach");
-		return -EINVAL;
-	}
-
-	progfd = prog_parse_fd(&argc, &argv);
-	if (progfd < 0)
-		return progfd;
-
-	attach_type = parse_attach_type(*argv);
-	if (attach_type == __MAX_BPF_ATTACH_TYPE) {
-		p_err("invalid attach type");
-		return -EINVAL;
-	}
-	NEXT_ARG();
+	int err, progfd;
+	int mapfd;
 
-	mapfd = map_parse_fd(&argc, &argv);
-	if (mapfd < 0)
-		return mapfd;
+	err = parse_attach_detach_args(argc, argv,
+				       &progfd, &attach_type, &mapfd);
+	if (err)
+		return err;
 
 	err = bpf_prog_detach2(progfd, mapfd, attach_type);
 	if (err) {
@@ -792,15 +798,17 @@ static int do_detach(int argc, char **argv)
 		jsonw_null(json_wtr);
 	return 0;
 }
-static int do_load(int argc, char **argv)
+
+static int load_with_options(int argc, char **argv, bool first_prog_only)
 {
 	enum bpf_attach_type expected_attach_type;
 	struct bpf_object_open_attr attr = {
 		.prog_type	= BPF_PROG_TYPE_UNSPEC,
 	};
 	struct map_replace *map_replace = NULL;
+	struct bpf_program *prog = NULL, *pos;
 	unsigned int old_map_fds = 0;
-	struct bpf_program *prog;
+	const char *pinmaps = NULL;
 	struct bpf_object *obj;
 	struct bpf_map *map;
 	const char *pinfile;
@@ -905,6 +913,13 @@ static int do_load(int argc, char **argv)
 				goto err_free_reuse_maps;
 			}
 			NEXT_ARG();
+		} else if (is_prefix(*argv, "pinmaps")) {
+			NEXT_ARG();
+
+			if (!REQ_ARGS(1))
+				goto err_free_reuse_maps;
+
+			pinmaps = GET_ARG();
 		} else {
 			p_err("expected no more arguments, 'type', 'map' or 'dev', got: '%s'?",
 			      *argv);
@@ -918,26 +933,25 @@ static int do_load(int argc, char **argv)
 		goto err_free_reuse_maps;
 	}
 
-	prog = bpf_program__next(NULL, obj);
-	if (!prog) {
-		p_err("object file doesn't contain any bpf program");
-		goto err_close_obj;
-	}
+	bpf_object__for_each_program(pos, obj) {
+		enum bpf_prog_type prog_type = attr.prog_type;
 
-	bpf_program__set_ifindex(prog, ifindex);
-	if (attr.prog_type == BPF_PROG_TYPE_UNSPEC) {
-		const char *sec_name = bpf_program__title(prog, false);
+		if (attr.prog_type == BPF_PROG_TYPE_UNSPEC) {
+			const char *sec_name = bpf_program__title(pos, false);
 
-		err = libbpf_prog_type_by_name(sec_name, &attr.prog_type,
-					       &expected_attach_type);
-		if (err < 0) {
-			p_err("failed to guess program type based on section name %s\n",
-			      sec_name);
-			goto err_close_obj;
+			err = libbpf_prog_type_by_name(sec_name, &prog_type,
+						       &expected_attach_type);
+			if (err < 0) {
+				p_err("failed to guess program type based on section name %s\n",
+				      sec_name);
+				goto err_close_obj;
+			}
 		}
+
+		bpf_program__set_ifindex(pos, ifindex);
+		bpf_program__set_type(pos, prog_type);
+		bpf_program__set_expected_attach_type(pos, expected_attach_type);
 	}
-	bpf_program__set_type(prog, attr.prog_type);
-	bpf_program__set_expected_attach_type(prog, expected_attach_type);
 
 	qsort(map_replace, old_map_fds, sizeof(*map_replace),
 	      map_replace_compar);
@@ -1003,9 +1017,39 @@ static int do_load(int argc, char **argv)
 		goto err_close_obj;
 	}
 
-	if (do_pin_fd(bpf_program__fd(prog), pinfile))
+	err = mount_bpffs_for_pin(pinfile);
+	if (err)
 		goto err_close_obj;
 
+	if (first_prog_only) {
+		prog = bpf_program__next(NULL, obj);
+		if (!prog) {
+			p_err("object file doesn't contain any bpf program");
+			goto err_close_obj;
+		}
+
+		err = bpf_obj_pin(bpf_program__fd(prog), pinfile);
+		if (err) {
+			p_err("failed to pin program %s",
+			      bpf_program__title(prog, false));
+			goto err_close_obj;
+		}
+	} else {
+		err = bpf_object__pin_programs(obj, pinfile);
+		if (err) {
+			p_err("failed to pin all programs");
+			goto err_close_obj;
+		}
+	}
+
+	if (pinmaps) {
+		err = bpf_object__pin_maps(obj, pinmaps);
+		if (err) {
+			p_err("failed to pin all maps");
+			goto err_unpin;
+		}
+	}
+
 	if (json_output)
 		jsonw_null(json_wtr);
 
@@ -1016,6 +1060,11 @@ static int do_load(int argc, char **argv)
 
 	return 0;
 
+err_unpin:
+	if (first_prog_only)
+		unlink(pinfile);
+	else
+		bpf_object__unpin_programs(obj, pinfile);
 err_close_obj:
 	bpf_object__close(obj);
 err_free_reuse_maps:
@@ -1025,6 +1074,16 @@ err_free_reuse_maps:
 	return -1;
 }
 
+static int do_load(int argc, char **argv)
+{
+	return load_with_options(argc, argv, true);
+}
+
+static int do_loadall(int argc, char **argv)
+{
+	return load_with_options(argc, argv, false);
+}
+
 static int do_help(int argc, char **argv)
 {
 	if (json_output) {
@@ -1037,10 +1096,12 @@ 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 [type TYPE] [dev NAME] \\\n"
-		"                         [map { idx IDX | name NAME } MAP]\n"
-		"       %s %s attach PROG ATTACH_TYPE MAP\n"
-		"       %s %s detach PROG ATTACH_TYPE MAP\n"
+		"       %s %s { load | loadall } OBJ  PATH \\\n"
+		"                         [type TYPE] [dev NAME] \\\n"
+		"                         [map { idx IDX | name NAME } MAP]\\\n"
+		"                         [pinmaps MAP_DIR]\n"
+		"       %s %s attach PROG ATTACH_TYPE [MAP]\n"
+		"       %s %s detach PROG ATTACH_TYPE [MAP]\n"
 		"       %s %s help\n"
 		"\n"
 		"       " HELP_SPEC_MAP "\n"
@@ -1052,7 +1113,8 @@ static int do_help(int argc, char **argv)
 		"                 cgroup/bind4 | cgroup/bind6 | cgroup/post_bind4 |\n"
 		"                 cgroup/post_bind6 | cgroup/connect4 | cgroup/connect6 |\n"
 		"                 cgroup/sendmsg4 | cgroup/sendmsg6 }\n"
-		"       ATTACH_TYPE := { msg_verdict | skb_verdict | skb_parse }\n"
+		"       ATTACH_TYPE := { msg_verdict | skb_verdict | skb_parse |\n"
+		"                        flow_dissector }\n"
 		"       " HELP_SPEC_OPTIONS "\n"
 		"",
 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
@@ -1069,6 +1131,7 @@ static const struct cmd cmds[] = {
 	{ "dump",	do_dump },
 	{ "pin",	do_pin },
 	{ "load",	do_load },
+	{ "loadall",	do_loadall },
 	{ "attach",	do_attach },
 	{ "detach",	do_detach },
 	{ 0 }