tools: bpftool: allow reuse of maps with bpftool prog load

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>
This commit is contained in:
Jakub Kicinski 2018-07-10 14:43:07 -07:00 committed by Daniel Borkmann
parent 26736eb9a4
commit 3ff5a4dc5d
5 changed files with 219 additions and 23 deletions

View File

@ -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
========

View File

@ -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

View File

@ -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,

View File

@ -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"

View File

@ -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"