Commit a7d22ca2 authored by Paul Chaignon's avatar Paul Chaignon Committed by Alexei Starovoitov
Browse files

bpftool: Match programs by name 



When working with frequently modified BPF programs, both the ID and the
tag may change.  bpftool currently doesn't provide a "stable" way to match
such programs.

This patch implements lookup by name for programs.  The show and dump
commands will return all programs with the given name, whereas other
commands will error out if several programs have the same name.

Signed-off-by: default avatarPaul Chaignon <paul.chaignon@orange.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Reviewed-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Link: https://lore.kernel.org/bpf/b5fc1a5dcfaeb5f16fc80295cdaa606dd2d91534.1576263640.git.paul.chaignon@gmail.com
parent ec202509

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

+1 −1
Original line number Diff line number Diff line
@@ -41,7 +41,7 @@ MAP COMMANDS 
|

|	*MAP* := { **id** *MAP_ID* | **pinned** *FILE* }

|	*DATA* := { [**hex**] *BYTES* }

|	*PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* }

|	*PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* | **name** *PROG_NAME* }

|	*VALUE* := { *DATA* | *MAP* | *PROG* }

|	*UPDATE_FLAGS* := { **any** | **exist** | **noexist** }

|	*TYPE* := { **hash** | **array** | **prog_array** | **perf_event_array** | **percpu_hash**

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

+6 −6
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ PROG COMMANDS 
|	**bpftool** **prog help**

|

|	*MAP* := { **id** *MAP_ID* | **pinned** *FILE* }

|	*PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* }

|	*PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* | **name** *PROG_NAME* }

|	*TYPE* := {

|		**socket** | **kprobe** | **kretprobe** | **classifier** | **action** |

|		**tracepoint** | **raw_tracepoint** | **xdp** | **perf_event** | **cgroup/skb** |
@@ -55,8 +55,8 @@ DESCRIPTION 
		  Show information about loaded programs.  If *PROG* is

		  specified show information only about given programs,

		  otherwise list all programs currently loaded on the system.

		  In case of **tag**, *PROG* may match several programs which

		  will all be shown.

		  In case of **tag** or **name**, *PROG* may match several

		  programs which will all be shown.



		  Output will start with program ID followed by program type and

		  zero or more named attributes (depending on kernel version).
@@ -75,9 +75,9 @@ DESCRIPTION 
		  output in human-readable format. In this case, **opcodes**

		  controls if raw opcodes should be printed as well.



		  In case of **tag**, *PROG* may match several programs which

		  will all be dumped.  However, if **file** or **visual** is

		  specified, *PROG* must match a single program.

		  In case of **tag** or **name**, *PROG* may match several

		  programs which will all be dumped.  However, if **file** or

		  **visual** is specified, *PROG* must match a single program.



		  If **file** is specified, the binary image will instead be

		  written to *FILE*.

tools/bpf/bpftool/bash-completion/bpftool

+16 −6
Original line number Diff line number Diff line
@@ -71,6 +71,12 @@ _bpftool_get_prog_tags() 
        command sed -n 's/.*"tag": "\(.*\)",$/\1/p' )" -- "$cur" ) )

}



_bpftool_get_prog_names()

{

    COMPREPLY+=( $( compgen -W "$( bpftool -jp prog 2>&1 | \

        command sed -n 's/.*"name": "\(.*\)",$/\1/p' )" -- "$cur" ) )

}



_bpftool_get_btf_ids()

{

    COMPREPLY+=( $( compgen -W "$( bpftool -jp btf 2>&1 | \
@@ -201,6 +207,10 @@ _bpftool() 
            _bpftool_get_prog_tags

            return 0

            ;;

        name)

            _bpftool_get_prog_names

            return 0

            ;;

        dev)

            _sysfs_get_netdevs

            return 0
@@ -263,7 +273,7 @@ _bpftool() 
                    ;;

            esac



            local PROG_TYPE='id pinned tag'

            local PROG_TYPE='id pinned tag name'

            local MAP_TYPE='id pinned'

            case $command in

                show|list)
@@ -559,7 +569,7 @@ _bpftool() 
                                    return 0

                                    ;;

                                prog_array)

                                    local PROG_TYPE='id pinned tag'

                                    local PROG_TYPE='id pinned tag name'

                                    COMPREPLY+=( $( compgen -W "$PROG_TYPE" \

                                        -- "$cur" ) )

                                    return 0
@@ -644,7 +654,7 @@ _bpftool() 
            esac

            ;;

        btf)

            local PROG_TYPE='id pinned tag'

            local PROG_TYPE='id pinned tag name'

            local MAP_TYPE='id pinned'

            case $command in

                dump)
@@ -735,7 +745,7 @@ _bpftool() 
                        connect6 sendmsg4 sendmsg6 recvmsg4 recvmsg6 sysctl \

                        getsockopt setsockopt'

                    local ATTACH_FLAGS='multi override'

                    local PROG_TYPE='id pinned tag'

                    local PROG_TYPE='id pinned tag name'

                    case $prev in

                        $command)

                            _filedir
@@ -760,7 +770,7 @@ _bpftool() 
                            elif [[ "$command" == "attach" ]]; then

                                # We have an attach type on the command line,

                                # but it is not the previous word, or

                                # "id|pinned|tag" (we already checked for

                                # "id|pinned|tag|name" (we already checked for

                                # that). This should only leave the case when

                                # we need attach flags for "attach" commamnd.

                                _bpftool_one_of_list "$ATTACH_FLAGS"
@@ -786,7 +796,7 @@ _bpftool() 
            esac

            ;;

        net)

            local PROG_TYPE='id pinned tag'

            local PROG_TYPE='id pinned tag name'

            local ATTACH_TYPES='xdp xdpgeneric xdpdrv xdpoffload'

            case $command in

                show|list)

tools/bpf/bpftool/main.h

+1 −1
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ 
#define BPF_TAG_FMT	"%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"



#define HELP_SPEC_PROGRAM						\

	"PROG := { id PROG_ID | pinned FILE | tag PROG_TAG }"

	"PROG := { id PROG_ID | pinned FILE | tag PROG_TAG | name PROG_NAME }"

#define HELP_SPEC_OPTIONS						\

	"OPTIONS := { {-j|--json} [{-p|--pretty}] | {-f|--bpffs} |\n"	\

	"\t            {-m|--mapcompat} | {-n|--nomount} }"

tools/bpf/bpftool/prog.c

+18 −4
Original line number Diff line number Diff line
@@ -82,7 +82,7 @@ static void print_boot_time(__u64 nsecs, char *buf, unsigned int size) 
		strftime(buf, size, "%FT%T%z", &load_tm);

}



static int prog_fd_by_tag(unsigned char *tag, int **fds)

static int prog_fd_by_nametag(void *nametag, int **fds, bool tag)

{

	unsigned int id = 0;

	int fd, nb_fds = 0;
@@ -116,7 +116,8 @@ static int prog_fd_by_tag(unsigned char *tag, int **fds) 
			goto err_close_fd;

		}



		if (memcmp(tag, info.tag, BPF_TAG_SIZE)) {

		if ((tag && memcmp(nametag, info.tag, BPF_TAG_SIZE)) ||

		    (!tag && strncmp(nametag, info.name, BPF_OBJ_NAME_LEN))) {

			close(fd);

			continue;

		}
@@ -174,7 +175,20 @@ static int prog_parse_fds(int *argc, char ***argv, int **fds) 
		}

		NEXT_ARGP();



		return prog_fd_by_tag(tag, fds);

		return prog_fd_by_nametag(tag, fds, true);

	} else if (is_prefix(**argv, "name")) {

		char *name;



		NEXT_ARGP();



		name = **argv;

		if (strlen(name) > BPF_OBJ_NAME_LEN - 1) {

			p_err("can't parse name");

			return -1;

		}

		NEXT_ARGP();



		return prog_fd_by_nametag(name, fds, false);

	} else if (is_prefix(**argv, "pinned")) {

		char *path;
@@ -189,7 +203,7 @@ static int prog_parse_fds(int *argc, char ***argv, int **fds) 
		return 1;

	}



	p_err("expected 'id', 'tag' or 'pinned', got: '%s'?", **argv);

	p_err("expected 'id', 'tag', 'name' or 'pinned', got: '%s'?", **argv);

	return -1;

}

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