From ebbd7f64a3fbe9e0f235e39fc244ee9735e2a52a Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Wed, 10 Nov 2021 11:46:27 +0000 Subject: [PATCH 1/5] bpftool: Fix memory leak in prog_dump() Following the extraction of prog_dump() from do_dump(), the struct btf allocated in prog_dump() is no longer freed on error; the struct bpf_prog_linfo is not freed at all. Make sure we release them before exiting the function. Fixes: ec2025095cf6 ("bpftool: Match several programs with same tag") Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211110114632.24537-2-quentin@isovalent.com --- tools/bpf/bpftool/prog.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index bf85c914f2fa1..e47e8b06cc3d6 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -709,8 +709,8 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode, char func_sig[1024]; unsigned char *buf; __u32 member_len; + int fd, err = -1; ssize_t n; - int fd; if (mode == DUMP_JITED) { if (info->jited_prog_len == 0 || !info->jited_prog_insns) { @@ -749,7 +749,7 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode, if (fd < 0) { p_err("can't open file %s: %s", filepath, strerror(errno)); - return -1; + goto exit_free; } n = write(fd, buf, member_len); @@ -757,7 +757,7 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode, if (n != (ssize_t)member_len) { p_err("error writing output file: %s", n < 0 ? strerror(errno) : "short write"); - return -1; + goto exit_free; } if (json_output) @@ -771,7 +771,7 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode, info->netns_ino, &disasm_opt); if (!name) - return -1; + goto exit_free; } if (info->nr_jited_func_lens && info->jited_func_lens) { @@ -866,9 +866,12 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode, kernel_syms_destroy(&dd); } - btf__free(btf); + err = 0; - return 0; +exit_free: + btf__free(btf); + bpf_prog_linfo__free(prog_linfo); + return err; } static int do_dump(int argc, char **argv) From 48f5aef4c458c19ab337eed8c95a6486cc014aa3 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Wed, 10 Nov 2021 11:46:28 +0000 Subject: [PATCH 2/5] bpftool: Remove inclusion of utilities.mak from Makefiles Bpftool's Makefile, and the Makefile for its documentation, both include scripts/utilities.mak, but they use none of the items defined in this file. Remove the includes. Fixes: 71bb428fe2c1 ("tools: bpf: add bpftool") Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211110114632.24537-3-quentin@isovalent.com --- tools/bpf/bpftool/Documentation/Makefile | 1 - tools/bpf/bpftool/Makefile | 1 - 2 files changed, 2 deletions(-) diff --git a/tools/bpf/bpftool/Documentation/Makefile b/tools/bpf/bpftool/Documentation/Makefile index 44b60784847be..692e1b947490c 100644 --- a/tools/bpf/bpftool/Documentation/Makefile +++ b/tools/bpf/bpftool/Documentation/Makefile @@ -1,6 +1,5 @@ # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) include ../../../scripts/Makefile.include -include ../../../scripts/utilities.mak INSTALL ?= install RM ?= rm -f diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile index 31dfef6a4121b..1b36c11a2a264 100644 --- a/tools/bpf/bpftool/Makefile +++ b/tools/bpf/bpftool/Makefile @@ -1,6 +1,5 @@ # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) include ../../scripts/Makefile.include -include ../../scripts/utilities.mak ifeq ($(srctree),) srctree := $(patsubst %/,%,$(dir $(CURDIR))) From 986dec18bbf41f50edc2e0aa4ac5ef8e0f64f328 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Wed, 10 Nov 2021 11:46:30 +0000 Subject: [PATCH 3/5] bpftool: Fix indent in option lists in the documentation Mixed indentation levels in the lists of options in bpftool's documentation produces some unexpected results. For the "bpftool" man page, it prints a warning: $ make -C bpftool.8 GEN bpftool.8 :26: (ERROR/3) Unexpected indentation. For other pages, there is no warning, but it results in a line break appearing in the option lists in the generated man pages. RST paragraphs should have a uniform indentation level. Let's fix it. Fixes: c07ba629df97 ("tools: bpftool: Update and synchronise option list in doc and help msg") Fixes: 8cc8c6357c8f ("tools: bpftool: Document and add bash completion for -L, -B options") Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211110114632.24537-5-quentin@isovalent.com --- tools/bpf/bpftool/Documentation/bpftool-btf.rst | 2 +- tools/bpf/bpftool/Documentation/bpftool-cgroup.rst | 2 +- tools/bpf/bpftool/Documentation/bpftool-gen.rst | 2 +- tools/bpf/bpftool/Documentation/bpftool-link.rst | 2 +- tools/bpf/bpftool/Documentation/bpftool-map.rst | 6 +++--- tools/bpf/bpftool/Documentation/bpftool-prog.rst | 8 ++++---- tools/bpf/bpftool/Documentation/bpftool.rst | 6 +++--- 7 files changed, 14 insertions(+), 14 deletions(-) diff --git a/tools/bpf/bpftool/Documentation/bpftool-btf.rst b/tools/bpf/bpftool/Documentation/bpftool-btf.rst index 88b28aa7431f6..4425d942dd39a 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-btf.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-btf.rst @@ -13,7 +13,7 @@ SYNOPSIS **bpftool** [*OPTIONS*] **btf** *COMMAND* *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | {**-d** | **--debug** } | - { **-B** | **--base-btf** } } + { **-B** | **--base-btf** } } *COMMANDS* := { **dump** | **help** } diff --git a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst index 3e4395eede4f7..13a217a2503d8 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst @@ -13,7 +13,7 @@ SYNOPSIS **bpftool** [*OPTIONS*] **cgroup** *COMMAND* *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** } | - { **-f** | **--bpffs** } } + { **-f** | **--bpffs** } } *COMMANDS* := { **show** | **list** | **tree** | **attach** | **detach** | **help** } diff --git a/tools/bpf/bpftool/Documentation/bpftool-gen.rst b/tools/bpf/bpftool/Documentation/bpftool-gen.rst index 2ef2f2df02799..2a137f8a4cea0 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-gen.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-gen.rst @@ -13,7 +13,7 @@ SYNOPSIS **bpftool** [*OPTIONS*] **gen** *COMMAND* *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** } | - { **-L** | **--use-loader** } } + { **-L** | **--use-loader** } } *COMMAND* := { **object** | **skeleton** | **help** } diff --git a/tools/bpf/bpftool/Documentation/bpftool-link.rst b/tools/bpf/bpftool/Documentation/bpftool-link.rst index 0de90f086238c..9434349636a5e 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-link.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-link.rst @@ -13,7 +13,7 @@ SYNOPSIS **bpftool** [*OPTIONS*] **link** *COMMAND* *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** } | - { **-f** | **--bpffs** } | { **-n** | **--nomount** } } + { **-f** | **--bpffs** } | { **-n** | **--nomount** } } *COMMANDS* := { **show** | **list** | **pin** | **help** } diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst index d0c4abe08abab..1445cadc15d4c 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-map.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst @@ -13,11 +13,11 @@ SYNOPSIS **bpftool** [*OPTIONS*] **map** *COMMAND* *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** } | - { **-f** | **--bpffs** } | { **-n** | **--nomount** } } + { **-f** | **--bpffs** } | { **-n** | **--nomount** } } *COMMANDS* := - { **show** | **list** | **create** | **dump** | **update** | **lookup** | **getnext** - | **delete** | **pin** | **help** } + { **show** | **list** | **create** | **dump** | **update** | **lookup** | **getnext** | + **delete** | **pin** | **help** } MAP COMMANDS ============= diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index 91608cb7e44a0..f27265bd589b4 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -13,12 +13,12 @@ SYNOPSIS **bpftool** [*OPTIONS*] **prog** *COMMAND* *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** } | - { **-f** | **--bpffs** } | { **-m** | **--mapcompat** } | { **-n** | **--nomount** } | - { **-L** | **--use-loader** } } + { **-f** | **--bpffs** } | { **-m** | **--mapcompat** } | { **-n** | **--nomount** } | + { **-L** | **--use-loader** } } *COMMANDS* := - { **show** | **list** | **dump xlated** | **dump jited** | **pin** | **load** - | **loadall** | **help** } + { **show** | **list** | **dump xlated** | **dump jited** | **pin** | **load** | + **loadall** | **help** } PROG COMMANDS ============= diff --git a/tools/bpf/bpftool/Documentation/bpftool.rst b/tools/bpf/bpftool/Documentation/bpftool.rst index bb23f55bb05ad..8ac86565c501e 100644 --- a/tools/bpf/bpftool/Documentation/bpftool.rst +++ b/tools/bpf/bpftool/Documentation/bpftool.rst @@ -19,14 +19,14 @@ SYNOPSIS *OBJECT* := { **map** | **program** | **cgroup** | **perf** | **net** | **feature** } *OPTIONS* := { { **-V** | **--version** } | - { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** } } + { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** } } *MAP-COMMANDS* := { **show** | **list** | **create** | **dump** | **update** | **lookup** | **getnext** | - **delete** | **pin** | **event_pipe** | **help** } + **delete** | **pin** | **event_pipe** | **help** } *PROG-COMMANDS* := { **show** | **list** | **dump jited** | **dump xlated** | **pin** | - **load** | **attach** | **detach** | **help** } + **load** | **attach** | **detach** | **help** } *CGROUP-COMMANDS* := { **show** | **list** | **attach** | **detach** | **help** } From 3811e2753a39efb8aa5b8c133dc24f6d26f6cd96 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Wed, 10 Nov 2021 11:46:31 +0000 Subject: [PATCH 4/5] bpftool: Update the lists of names for maps and prog-attach types To support the different BPF map or attach types, bpftool must remain up-to-date with the types supported by the kernel. Let's update the lists, by adding the missing Bloom filter map type and the perf_event attach type. Both missing items were found with test_bpftool_synctypes.py. Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211110114632.24537-6-quentin@isovalent.com --- tools/bpf/bpftool/Documentation/bpftool-map.rst | 2 +- tools/bpf/bpftool/bash-completion/bpftool | 3 ++- tools/bpf/bpftool/common.c | 1 + tools/bpf/bpftool/map.c | 3 ++- 4 files changed, 6 insertions(+), 3 deletions(-) diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst index 1445cadc15d4c..991d18fd84f27 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-map.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst @@ -52,7 +52,7 @@ MAP COMMANDS | | **devmap** | **devmap_hash** | **sockmap** | **cpumap** | **xskmap** | **sockhash** | | **cgroup_storage** | **reuseport_sockarray** | **percpu_cgroup_storage** | | **queue** | **stack** | **sk_storage** | **struct_ops** | **ringbuf** | **inode_storage** - | **task_storage** } +| | **task_storage** | **bloom_filter** } DESCRIPTION =========== diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool index 4a1b02ff72c1c..493753a4962e9 100644 --- a/tools/bpf/bpftool/bash-completion/bpftool +++ b/tools/bpf/bpftool/bash-completion/bpftool @@ -710,7 +710,8 @@ _bpftool() hash_of_maps devmap devmap_hash sockmap cpumap \ xskmap sockhash cgroup_storage reuseport_sockarray \ percpu_cgroup_storage queue stack sk_storage \ - struct_ops inode_storage task_storage ringbuf' + struct_ops ringbuf inode_storage task_storage \ + bloom_filter' COMPREPLY=( $( compgen -W "$BPFTOOL_MAP_CREATE_TYPES" -- "$cur" ) ) return 0 ;; diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c index 511eccdbdfe6d..fa8eb81343449 100644 --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c @@ -74,6 +74,7 @@ const char * const attach_type_name[__MAX_BPF_ATTACH_TYPE] = { [BPF_XDP] = "xdp", [BPF_SK_REUSEPORT_SELECT] = "sk_skb_reuseport_select", [BPF_SK_REUSEPORT_SELECT_OR_MIGRATE] = "sk_skb_reuseport_select_or_migrate", + [BPF_PERF_EVENT] = "perf_event", }; void p_err(const char *fmt, ...) diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index cae1f11192969..68cb121e65c4b 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -53,6 +53,7 @@ const char * const map_type_name[] = { [BPF_MAP_TYPE_RINGBUF] = "ringbuf", [BPF_MAP_TYPE_INODE_STORAGE] = "inode_storage", [BPF_MAP_TYPE_TASK_STORAGE] = "task_storage", + [BPF_MAP_TYPE_BLOOM_FILTER] = "bloom_filter", }; const size_t map_type_name_size = ARRAY_SIZE(map_type_name); @@ -1477,7 +1478,7 @@ static int do_help(int argc, char **argv) " devmap | devmap_hash | sockmap | cpumap | xskmap | sockhash |\n" " cgroup_storage | reuseport_sockarray | percpu_cgroup_storage |\n" " queue | stack | sk_storage | struct_ops | ringbuf | inode_storage |\n" - " task_storage }\n" + " task_storage | bloom_filter }\n" " " HELP_SPEC_OPTIONS " |\n" " {-f|--bpffs} | {-n|--nomount} }\n" "", From b06be5651f08bc5bc305e2a3c722ddb33b783ee5 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Wed, 10 Nov 2021 11:46:32 +0000 Subject: [PATCH 5/5] bpftool: Fix mixed indentation in documentation Some paragraphs in bpftool's documentation have a mix of tabs and spaces for indentation. Let's make it consistent. This patch brings no change to the text content. Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211110114632.24537-7-quentin@isovalent.com --- .../bpftool/Documentation/bpftool-cgroup.rst | 10 +-- .../bpf/bpftool/Documentation/bpftool-net.rst | 66 +++++++++---------- 2 files changed, 38 insertions(+), 38 deletions(-) diff --git a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst index 13a217a2503d8..8069d37dd991c 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst @@ -30,9 +30,9 @@ CGROUP COMMANDS | *PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* } | *ATTACH_TYPE* := { **ingress** | **egress** | **sock_create** | **sock_ops** | **device** | | **bind4** | **bind6** | **post_bind4** | **post_bind6** | **connect4** | **connect6** | -| **getpeername4** | **getpeername6** | **getsockname4** | **getsockname6** | **sendmsg4** | -| **sendmsg6** | **recvmsg4** | **recvmsg6** | **sysctl** | **getsockopt** | **setsockopt** | -| **sock_release** } +| **getpeername4** | **getpeername6** | **getsockname4** | **getsockname6** | **sendmsg4** | +| **sendmsg6** | **recvmsg4** | **recvmsg6** | **sysctl** | **getsockopt** | **setsockopt** | +| **sock_release** } | *ATTACH_FLAGS* := { **multi** | **override** } DESCRIPTION @@ -98,9 +98,9 @@ DESCRIPTION **sendmsg6** call to sendto(2), sendmsg(2), sendmmsg(2) for an unconnected udp6 socket (since 4.18); **recvmsg4** call to recvfrom(2), recvmsg(2), recvmmsg(2) for - an unconnected udp4 socket (since 5.2); + an unconnected udp4 socket (since 5.2); **recvmsg6** call to recvfrom(2), recvmsg(2), recvmmsg(2) for - an unconnected udp6 socket (since 5.2); + an unconnected udp6 socket (since 5.2); **sysctl** sysctl access (since 5.2); **getsockopt** call to getsockopt (since 5.3); **setsockopt** call to setsockopt (since 5.3); diff --git a/tools/bpf/bpftool/Documentation/bpftool-net.rst b/tools/bpf/bpftool/Documentation/bpftool-net.rst index 1ae0375e8fea6..7ec57535a7c1b 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-net.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-net.rst @@ -31,44 +31,44 @@ NET COMMANDS DESCRIPTION =========== **bpftool net { show | list }** [ **dev** *NAME* ] - List bpf program attachments in the kernel networking subsystem. - - Currently, only device driver xdp attachments and tc filter - classification/action attachments are implemented, i.e., for - program types **BPF_PROG_TYPE_SCHED_CLS**, - **BPF_PROG_TYPE_SCHED_ACT** and **BPF_PROG_TYPE_XDP**. - For programs attached to a particular cgroup, e.g., - **BPF_PROG_TYPE_CGROUP_SKB**, **BPF_PROG_TYPE_CGROUP_SOCK**, - **BPF_PROG_TYPE_SOCK_OPS** and **BPF_PROG_TYPE_CGROUP_SOCK_ADDR**, - users can use **bpftool cgroup** to dump cgroup attachments. - For sk_{filter, skb, msg, reuseport} and lwt/seg6 - bpf programs, users should consult other tools, e.g., iproute2. - - The current output will start with all xdp program attachments, followed by - all tc class/qdisc bpf program attachments. Both xdp programs and - tc programs are ordered based on ifindex number. If multiple bpf - programs attached to the same networking device through **tc filter**, - the order will be first all bpf programs attached to tc classes, then - all bpf programs attached to non clsact qdiscs, and finally all - bpf programs attached to root and clsact qdisc. + List bpf program attachments in the kernel networking subsystem. + + Currently, only device driver xdp attachments and tc filter + classification/action attachments are implemented, i.e., for + program types **BPF_PROG_TYPE_SCHED_CLS**, + **BPF_PROG_TYPE_SCHED_ACT** and **BPF_PROG_TYPE_XDP**. + For programs attached to a particular cgroup, e.g., + **BPF_PROG_TYPE_CGROUP_SKB**, **BPF_PROG_TYPE_CGROUP_SOCK**, + **BPF_PROG_TYPE_SOCK_OPS** and **BPF_PROG_TYPE_CGROUP_SOCK_ADDR**, + users can use **bpftool cgroup** to dump cgroup attachments. + For sk_{filter, skb, msg, reuseport} and lwt/seg6 + bpf programs, users should consult other tools, e.g., iproute2. + + The current output will start with all xdp program attachments, followed by + all tc class/qdisc bpf program attachments. Both xdp programs and + tc programs are ordered based on ifindex number. If multiple bpf + programs attached to the same networking device through **tc filter**, + the order will be first all bpf programs attached to tc classes, then + all bpf programs attached to non clsact qdiscs, and finally all + bpf programs attached to root and clsact qdisc. **bpftool** **net attach** *ATTACH_TYPE* *PROG* **dev** *NAME* [ **overwrite** ] - Attach bpf program *PROG* to network interface *NAME* with - type specified by *ATTACH_TYPE*. Previously attached bpf program - can be replaced by the command used with **overwrite** option. - Currently, only XDP-related modes are supported for *ATTACH_TYPE*. + Attach bpf program *PROG* to network interface *NAME* with + type specified by *ATTACH_TYPE*. Previously attached bpf program + can be replaced by the command used with **overwrite** option. + Currently, only XDP-related modes are supported for *ATTACH_TYPE*. - *ATTACH_TYPE* can be of: - **xdp** - try native XDP and fallback to generic XDP if NIC driver does not support it; - **xdpgeneric** - Generic XDP. runs at generic XDP hook when packet already enters receive path as skb; - **xdpdrv** - Native XDP. runs earliest point in driver's receive path; - **xdpoffload** - Offload XDP. runs directly on NIC on each packet reception; + *ATTACH_TYPE* can be of: + **xdp** - try native XDP and fallback to generic XDP if NIC driver does not support it; + **xdpgeneric** - Generic XDP. runs at generic XDP hook when packet already enters receive path as skb; + **xdpdrv** - Native XDP. runs earliest point in driver's receive path; + **xdpoffload** - Offload XDP. runs directly on NIC on each packet reception; **bpftool** **net detach** *ATTACH_TYPE* **dev** *NAME* - Detach bpf program attached to network interface *NAME* with - type specified by *ATTACH_TYPE*. To detach bpf program, same - *ATTACH_TYPE* previously used for attach must be specified. - Currently, only XDP-related modes are supported for *ATTACH_TYPE*. + Detach bpf program attached to network interface *NAME* with + type specified by *ATTACH_TYPE*. To detach bpf program, same + *ATTACH_TYPE* previously used for attach must be specified. + Currently, only XDP-related modes are supported for *ATTACH_TYPE*. **bpftool net help** Print short help message.