tools: bpftool: allow reuse of maps with bpftool prog load (3ff5a4dc) · Commits · e / devices / android_kernel_fairphone_FP5

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

+18 −2

Original line number	Diff line number	Diff line
		@@ -24,9 +24,10 @@ 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] [dev NAME]
		\| bpftool prog load OBJ FILE [type TYPE] [map {idx IDX \| name NAME} MAP] [dev NAME]
		\| bpftool prog help
		\|
		\| MAP := { id MAP_ID \| pinned FILE }
		\| PROG := { id PROG_ID \| pinned FILE \| tag PROG_TAG }
		\| TYPE := {
		\| socket \| kprobe \| kretprobe \| classifier \| action \|
		@@ -73,10 +74,17 @@ DESCRIPTION

		Note: FILE must be located in bpffs mount.

		bpftool prog load OBJ FILE [type TYPE] [dev NAME]
		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.
		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
		object being loaded. map parameter allows for the reuse
		of existing maps. It can be specified multiple times, each
		time for a different map. IDX refers to index of the map
		to be replaced in the ELF file counting from 0, while NAME
		allows to replace a map by name. MAP specifies the map to
		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).

		@@ -172,6 +180,14 @@ EXAMPLES
		mov %rbx,0x0(%rbp)
		48 89 5d 00

		\|
		\| # bpftool prog load xdp1_kern.o /sys/fs/bpf/xdp1 type xdp map name rxcnt id 7
		\| # bpftool prog show pinned /sys/fs/bpf/xdp1
		\| 9: xdp name xdp_prog1 tag 539ec6ce11b52f98 gpl
		\| loaded_at 2018-06-25T16:17:31-0700 uid 0
		\| xlated 488B jited 336B memlock 4096B map_ids 7
		\| # rm /sys/fs/bpf/xdp1
		\|

		SEE ALSO
		========

tools/bpf/bpftool/bash-completion/bpftool

+61 −6

Original line number	Diff line number	Diff line
		@@ -99,6 +99,29 @@ _bpftool_get_prog_tags()
		command sed -n 's/."tag": "$.$",$/\1/p' )" -- "$cur" ) )
		}

		_bpftool_get_obj_map_names()
		{
		local obj

		obj=$1

		maps=$(objdump -j maps -t $obj 2>/dev/null \| \
		command awk '/g . maps/ {print $NF}')

		COMPREPLY+=( $( compgen -W "$maps" -- "$cur" ) )
		}

		_bpftool_get_obj_map_idxs()
		{
		local obj

		obj=$1

		nmaps=$(objdump -j maps -t $obj 2>/dev/null \| grep -c 'g . maps')

		COMPREPLY+=( $( compgen -W "$(seq 0 $((nmaps - 1)))" -- "$cur" ) )
		}

		_sysfs_get_netdevs()
		{
		COMPREPLY+=( $( compgen -W "$( ls /sys/class/net 2>/dev/null )" -- \
		@@ -220,12 +243,14 @@ _bpftool()
		# Completion depends on object and command in use
		case $object in
		prog)
		if [[ $command != "load" ]]; then
		case $prev in
		id)
		_bpftool_get_prog_ids
		return 0
		;;
		esac
		fi

		local PROG_TYPE='id pinned tag'
		case $command in
		@@ -268,22 +293,52 @@ _bpftool()
		return 0
		;;
		load)
		local obj

		if [[ ${#words[@]} -lt 6 ]]; then
		_filedir
		return 0
		fi

		obj=${words[3]}

		if [[ ${words[-4]} == "map" ]]; then
		COMPREPLY=( $( compgen -W "id pinned" -- "$cur" ) )
		return 0
		fi
		if [[ ${words[-3]} == "map" ]]; then
		if [[ ${words[-2]} == "idx" ]]; then
		_bpftool_get_obj_map_idxs $obj
		elif [[ ${words[-2]} == "name" ]]; then
		_bpftool_get_obj_map_names $obj
		fi
		return 0
		fi
		if [[ ${words[-2]} == "map" ]]; then
		COMPREPLY=( $( compgen -W "idx name" -- "$cur" ) )
		return 0
		fi

		case $prev in
		type)
		COMPREPLY=( $( compgen -W "socket kprobe kretprobe classifier action tracepoint raw_tracepoint xdp perf_event cgroup/skb cgroup/sock cgroup/dev lwt_in lwt_out lwt_xmit lwt_seg6local sockops sk_skb sk_msg lirc_mode2 cgroup/bind4 cgroup/bind6 cgroup/connect4 cgroup/connect6 cgroup/sendmsg4 cgroup/sendmsg6 cgroup/post_bind4 cgroup/post_bind6" -- \
		"$cur" ) )
		return 0
		;;
		id)
		_bpftool_get_map_ids
		return 0
		;;
		pinned)
		_filedir
		return 0
		;;
		dev)
		_sysfs_get_netdevs
		return 0
		;;
		*)
		COMPREPLY=( $( compgen -W "map" -- "$cur" ) )
		_bpftool_once_attr 'type'
		_bpftool_once_attr 'dev'
		return 0

tools/bpf/bpftool/main.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -75,6 +75,8 @@
		"PROG := { id PROG_ID \| pinned FILE \| tag PROG_TAG }"
		#define HELP_SPEC_OPTIONS \
		"OPTIONS := { {-j\|--json} [{-p\|--pretty}] \| {-f\|--bpffs} }"
		#define HELP_SPEC_MAP \
		"MAP := { id MAP_ID \| pinned FILE }"

		enum bpf_obj_type {
		BPF_OBJ_UNKNOWN,
		@@ -136,6 +138,7 @@ int do_cgroup(int argc, char **arg);
		int do_perf(int argc, char **arg);

		int prog_parse_fd(int argc, char **argv);
		int map_parse_fd(int argc, char **argv);
		int map_parse_fd_and_info(int argc, char *argv, void info, __u32 *info_len);

		void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,

tools/bpf/bpftool/map.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -93,7 +93,7 @@ static void alloc_value(struct bpf_map_info info)
		return malloc(info->value_size);
		}

		static int map_parse_fd(int argc, char **argv)
		int map_parse_fd(int argc, char **argv)
		{
		int fd;

		@@ -824,7 +824,7 @@ static int do_help(int argc, char **argv)
		" %s %s event_pipe MAP [cpu N index M]\n"
		" %s %s help\n"
		"\n"
		" MAP := { id MAP_ID \| pinned FILE }\n"
		" " HELP_SPEC_MAP "\n"
		" DATA := { [hex] BYTES }\n"
		" " HELP_SPEC_PROGRAM "\n"
		" VALUE := { DATA \| MAP \| PROG }\n"

tools/bpf/bpftool/prog.c

+135 −13

Original line number	Diff line number	Diff line
		@@ -31,6 +31,7 @@
		* SOFTWARE.
		*/

		#define _GNU_SOURCE
		#include <errno.h>
		#include <fcntl.h>
		#include <stdarg.h>
		@@ -682,18 +683,34 @@ static int do_pin(int argc, char **argv)
		return err;
		}

		struct map_replace {
		int idx;
		int fd;
		char *name;
		};

		int map_replace_compar(const void p1, const void p2)
		{
		const struct map_replace a = p1, b = p2;

		return a->idx - b->idx;
		}

		static int do_load(int argc, char **argv)
		{
		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;
		unsigned int old_map_fds = 0;
		struct bpf_program *prog;
		struct bpf_object *obj;
		struct bpf_map *map;
		const char *pinfile;
		unsigned int i, j;
		__u32 ifindex = 0;
		int err;
		int idx, err;

		if (!REQ_ARGS(2))
		return -1;
		@@ -708,16 +725,16 @@ static int do_load(int argc, char **argv)

		if (attr.prog_type != BPF_PROG_TYPE_UNSPEC) {
		p_err("program type already specified");
		return -1;
		goto err_free_reuse_maps;
		}
		if (!REQ_ARGS(1))
		return -1;
		goto err_free_reuse_maps;

		/* Put a '/' at the end of type to appease libbpf */
		type = malloc(strlen(*argv) + 2);
		if (!type) {
		p_err("mem alloc failed");
		return -1;
		goto err_free_reuse_maps;
		}
		*type = 0;
		strcat(type, *argv);
		@@ -728,37 +745,81 @@ static int do_load(int argc, char **argv)
		free(type);
		if (err < 0) {
		p_err("unknown program type '%s'", *argv);
		return err;
		goto err_free_reuse_maps;
		}
		NEXT_ARG();
		} else if (is_prefix(*argv, "map")) {
		char endptr, name;
		int fd;

		NEXT_ARG();

		if (!REQ_ARGS(4))
		goto err_free_reuse_maps;

		if (is_prefix(*argv, "idx")) {
		NEXT_ARG();

		idx = strtoul(*argv, &endptr, 0);
		if (*endptr) {
		p_err("can't parse %s as IDX", *argv);
		goto err_free_reuse_maps;
		}
		name = NULL;
		} else if (is_prefix(*argv, "name")) {
		NEXT_ARG();

		name = *argv;
		idx = -1;
		} else {
		p_err("expected 'idx' or 'name', got: '%s'?",
		*argv);
		goto err_free_reuse_maps;
		}
		NEXT_ARG();

		fd = map_parse_fd(&argc, &argv);
		if (fd < 0)
		goto err_free_reuse_maps;

		map_replace = reallocarray(map_replace, old_map_fds + 1,
		sizeof(*map_replace));
		if (!map_replace) {
		p_err("mem alloc failed");
		goto err_free_reuse_maps;
		}
		map_replace[old_map_fds].idx = idx;
		map_replace[old_map_fds].name = name;
		map_replace[old_map_fds].fd = fd;
		old_map_fds++;
		} else if (is_prefix(*argv, "dev")) {
		NEXT_ARG();

		if (ifindex) {
		p_err("offload device already specified");
		return -1;
		goto err_free_reuse_maps;
		}
		if (!REQ_ARGS(1))
		return -1;
		goto err_free_reuse_maps;

		ifindex = if_nametoindex(*argv);
		if (!ifindex) {
		p_err("unrecognized netdevice '%s': %s",
		*argv, strerror(errno));
		return -1;
		goto err_free_reuse_maps;
		}
		NEXT_ARG();
		} else {
		p_err("expected no more arguments, 'type' or 'dev', got: '%s'?",
		p_err("expected no more arguments, 'type', 'map' or 'dev', got: '%s'?",
		*argv);
		return -1;
		goto err_free_reuse_maps;
		}
		}

		obj = bpf_object__open_xattr(&attr);
		if (IS_ERR_OR_NULL(obj)) {
		p_err("failed to open object file");
		return -1;
		goto err_free_reuse_maps;
		}

		prog = bpf_program__next(NULL, obj);
		@@ -782,10 +843,62 @@ static int do_load(int argc, char **argv)
		bpf_program__set_type(prog, attr.prog_type);
		bpf_program__set_expected_attach_type(prog, expected_attach_type);

		bpf_map__for_each(map, obj)
		qsort(map_replace, old_map_fds, sizeof(*map_replace),
		map_replace_compar);

		/* After the sort maps by name will be first on the list, because they
		* have idx == -1. Resolve them.
		*/
		j = 0;
		while (j < old_map_fds && map_replace[j].name) {
		i = 0;
		bpf_map__for_each(map, obj) {
		if (!strcmp(bpf_map__name(map), map_replace[j].name)) {
		map_replace[j].idx = i;
		break;
		}
		i++;
		}
		if (map_replace[j].idx == -1) {
		p_err("unable to find map '%s'", map_replace[j].name);
		goto err_close_obj;
		}
		j++;
		}
		/* Resort if any names were resolved */
		if (j)
		qsort(map_replace, old_map_fds, sizeof(*map_replace),
		map_replace_compar);

		/* Set ifindex and name reuse */
		j = 0;
		idx = 0;
		bpf_map__for_each(map, obj) {
		if (!bpf_map__is_offload_neutral(map))
		bpf_map__set_ifindex(map, ifindex);

		if (j < old_map_fds && idx == map_replace[j].idx) {
		err = bpf_map__reuse_fd(map, map_replace[j++].fd);
		if (err) {
		p_err("unable to set up map reuse: %d", err);
		goto err_close_obj;
		}

		/* Next reuse wants to apply to the same map */
		if (j < old_map_fds && map_replace[j].idx == idx) {
		p_err("replacement for map idx %d specified more than once",
		idx);
		goto err_close_obj;
		}
		}

		idx++;
		}
		if (j < old_map_fds) {
		p_err("map idx '%d' not used", map_replace[j].idx);
		goto err_close_obj;
		}

		err = bpf_object__load(obj);
		if (err) {
		p_err("failed to load object file");
		@@ -799,11 +912,18 @@ static int do_load(int argc, char **argv)
		jsonw_null(json_wtr);

		bpf_object__close(obj);
		for (i = 0; i < old_map_fds; i++)
		close(map_replace[i].fd);
		free(map_replace);

		return 0;

		err_close_obj:
		bpf_object__close(obj);
		err_free_reuse_maps:
		for (i = 0; i < old_map_fds; i++)
		close(map_replace[i].fd);
		free(map_replace);
		return -1;
		}

		@@ -819,9 +939,11 @@ 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"
		" %s %s load OBJ FILE [type TYPE] [dev NAME] \\\n"
		" [map { idx IDX \| name NAME } MAP]\n"
		" %s %s help\n"
		"\n"
		" " HELP_SPEC_MAP "\n"
		" " HELP_SPEC_PROGRAM "\n"
		" TYPE := { socket \| kprobe \| kretprobe \| classifier \| action \|\n"
		" tracepoint \| raw_tracepoint \| xdp \| perf_event \| cgroup/skb \|\n"

Original line number	Diff line number	Diff line
		@@ -24,9 +24,10 @@ 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] [dev NAME]
		\| bpftool prog load OBJ FILE [type TYPE] [map {idx IDX \| name NAME} MAP] [dev NAME]
		\| bpftool prog help
		\|
		\| MAP := { id MAP_ID \| pinned FILE }
		\| PROG := { id PROG_ID \| pinned FILE \| tag PROG_TAG }
		\| TYPE := {
		\| socket \| kprobe \| kretprobe \| classifier \| action \|
		@@ -73,10 +74,17 @@ DESCRIPTION

		Note: FILE must be located in bpffs mount.

		bpftool prog load OBJ FILE [type TYPE] [dev NAME]
		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.
		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
		object being loaded. map parameter allows for the reuse
		of existing maps. It can be specified multiple times, each
		time for a different map. IDX refers to index of the map
		to be replaced in the ELF file counting from 0, while NAME
		allows to replace a map by name. MAP specifies the map to
		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).

		@@ -172,6 +180,14 @@ EXAMPLES
		mov %rbx,0x0(%rbp)
		48 89 5d 00

		\|
		\| # bpftool prog load xdp1_kern.o /sys/fs/bpf/xdp1 type xdp map name rxcnt id 7
		\| # bpftool prog show pinned /sys/fs/bpf/xdp1
		\| 9: xdp name xdp_prog1 tag 539ec6ce11b52f98 gpl
		\| loaded_at 2018-06-25T16:17:31-0700 uid 0
		\| xlated 488B jited 336B memlock 4096B map_ids 7
		\| # rm /sys/fs/bpf/xdp1
		\|

		SEE ALSO
		========