[PATCH bpf-next 2/2] tools: bpftool: add "bpftool map freeze" subcommand
From: Quentin Monnet <hidden>
Date: 2019-08-21 08:52:33
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [tooling] (bpftool), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Quentin Monnet, Linus Torvalds
Add a new subcommand to freeze maps from user space. Signed-off-by: Quentin Monnet <redacted> Reviewed-by: Jakub Kicinski <redacted> --- .../bpf/bpftool/Documentation/bpftool-map.rst | 9 +++++ tools/bpf/bpftool/bash-completion/bpftool | 4 +-- tools/bpf/bpftool/map.c | 34 ++++++++++++++++++- 3 files changed, 44 insertions(+), 3 deletions(-)
diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst
index 61d1d270eb5e..1c0f7146aab0 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-map.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst@@ -36,6 +36,7 @@ MAP COMMANDS | **bpftool** **map pop** *MAP* | **bpftool** **map enqueue** *MAP* **value** *VALUE* | **bpftool** **map dequeue** *MAP* +| **bpftool** **map freeze** *MAP* | **bpftool** **map help** | | *MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
@@ -127,6 +128,14 @@ DESCRIPTION **bpftool map dequeue** *MAP* Dequeue and print **value** from the queue. + **bpftool map freeze** *MAP* + Freeze the map as read-only from user space. Entries from a + frozen map can not longer be updated or deleted with the + **bpf\ ()** system call. This operation is not reversible, + and the map remains immutable from user space until its + destruction. However, read and write permissions for BPF + programs to the map remain unchanged. + **bpftool map help** Print short help message.
diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool
index 2ffd351f9dbf..70493a6da206 100644
--- a/tools/bpf/bpftool/bash-completion/bpftool
+++ b/tools/bpf/bpftool/bash-completion/bpftool@@ -449,7 +449,7 @@ _bpftool() map) local MAP_TYPE='id pinned' case $command in - show|list|dump|peek|pop|dequeue) + show|list|dump|peek|pop|dequeue|freeze) case $prev in $command) COMPREPLY=( $( compgen -W "$MAP_TYPE" -- "$cur" ) )
@@ -638,7 +638,7 @@ _bpftool() [[ $prev == $object ]] && \ COMPREPLY=( $( compgen -W 'delete dump getnext help \ lookup pin event_pipe show list update create \ - peek push enqueue pop dequeue' -- \ + peek push enqueue pop dequeue freeze' -- \ "$cur" ) ) ;; esac
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index af2e9eb9747b..de61d73b9030 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c@@ -1262,6 +1262,35 @@ static int do_pop_dequeue(int argc, char **argv) return err; } +static int do_freeze(int argc, char **argv) +{ + int err, fd; + + if (!REQ_ARGS(2)) + return -1; + + fd = map_parse_fd(&argc, &argv); + if (fd < 0) + return -1; + + if (argc) { + close(fd); + return BAD_ARG(); + } + + err = bpf_map_freeze(fd); + close(fd); + if (err) { + p_err("failed to freeze map: %s", strerror(errno)); + return err; + } + + if (json_output) + jsonw_null(json_wtr); + + return 0; +} + static int do_help(int argc, char **argv) { if (json_output) {
@@ -1286,6 +1315,7 @@ static int do_help(int argc, char **argv) " %s %s pop MAP\n" " %s %s enqueue MAP value VALUE\n" " %s %s dequeue MAP\n" + " %s %s freeze MAP\n" " %s %s help\n" "\n" " " HELP_SPEC_MAP "\n"
@@ -1304,7 +1334,8 @@ static int do_help(int argc, char **argv) bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], - bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]); + bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], + bin_name, argv[-2]); return 0; }
@@ -1326,6 +1357,7 @@ static const struct cmd cmds[] = { { "enqueue", do_update }, { "pop", do_pop_dequeue }, { "dequeue", do_pop_dequeue }, + { "freeze", do_freeze }, { 0 } };
--
2.17.1