Add a new subcommand to freeze maps from user space.
Signed-off-by: Quentin Monnet <quentin.monnet@xxxxxxxxxxxxx>
Reviewed-by: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>
---
.../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
