From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Tue, 10 Jul 2018 14:43:07 -0700
Subject: tools: bpftool: allow reuse of maps with bpftool prog load
Patch-mainline: v4.19-rc1
Git-commit: 3ff5a4dc5d890963e669fc99cc62ee07d1da24e8
References: bsc#1109837
Add map parameter to prog load which will allow reuse of existing
maps instead of creating new ones.
We need feature detection and compat code for reallocarray, since
it's not available in many libc versions.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
tools/bpf/bpftool/Documentation/bpftool-prog.rst | 20 ++-
tools/bpf/bpftool/bash-completion/bpftool | 67 +++++++++-
tools/bpf/bpftool/main.h | 3
tools/bpf/bpftool/map.c | 4
tools/bpf/bpftool/prog.c | 148 ++++++++++++++++++++---
5 files changed, 219 insertions(+), 23 deletions(-)
--- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -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
========
--- a/tools/bpf/bpftool/bash-completion/bpftool
+++ b/tools/bpf/bpftool/bash-completion/bpftool
@@ -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)
- case $prev in
- id)
- _bpftool_get_prog_ids
- return 0
- ;;
- esac
+ 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
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -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,
@@ -135,6 +137,7 @@ int do_event_pipe(int argc, char **argv)
int do_cgroup(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,
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -95,7 +95,7 @@ static void *alloc_value(struct bpf_map_
return malloc(info->value_size);
}
-static int map_parse_fd(int *argc, char ***argv)
+int map_parse_fd(int *argc, char ***argv)
{
int fd;
@@ -828,7 +828,7 @@ 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"
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -31,6 +31,7 @@
* SOFTWARE.
*/
+#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
@@ -681,18 +682,34 @@ 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;
@@ -707,16 +724,16 @@ 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);
@@ -727,37 +744,81 @@ 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);
@@ -781,10 +842,62 @@ 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");
@@ -798,11 +911,18 @@ 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;
}
@@ -818,9 +938,11 @@ 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"