On 21/06/2022 10:23, Konstantin Meskhidze wrote:
This commit adds network demo. It's possible to
allow a sandoxer to bind/connect to a list of
particular ports restricting networks actions to
the rest of ports.
Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@xxxxxxxxxx>
---
Changes since v5:
* Makes network ports sandboxing optional.
* Fixes some logic errors.
* Formats code with clang-format-14.
Changes since v4:
* Adds ENV_TCP_BIND_NAME "LL_TCP_BIND" and
ENV_TCP_CONNECT_NAME "LL_TCP_CONNECT" variables
to insert TCP ports.
* Renames populate_ruleset() to populate_ruleset_fs().
* Adds populate_ruleset_net() and parse_port_num() helpers.
* Refactors main() to support network sandboxing.
---
samples/landlock/sandboxer.c | 118 +++++++++++++++++++++++++++++++----
1 file changed, 107 insertions(+), 11 deletions(-)
diff --git a/samples/landlock/sandboxer.c b/samples/landlock/sandboxer.c
index 3e404e51ec64..0606c676fded 100644
--- a/samples/landlock/sandboxer.c
+++ b/samples/landlock/sandboxer.c
[...]
@@ -232,16 +308,36 @@ int main(const int argc, char *const argv[], char *const *const envp)
access_fs_rw &= ~ACCESS_ABI_2;
We need to check the ABI to make this sample work without a kernel
supporting Landlock network access rights, and error out if the user
explicitely asked for it anyway (with the environement variable).
}
+ /* Adds optionally network bind() support. */
+ env_port_name = getenv(ENV_TCP_BIND_NAME);
+ if (env_port_name) {
+ access_net_tcp |= LANDLOCK_ACCESS_NET_BIND_TCP;
+ }
+ /* Adds optionally network connect() support. */
+ env_port_name = getenv(ENV_TCP_CONNECT_NAME);
+ if (env_port_name) {
+ access_net_tcp |= LANDLOCK_ACCESS_NET_CONNECT_TCP;
+ }
+ ruleset_attr.handled_access_net = access_net_tcp;
+
ruleset_fd =
landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
if (ruleset_fd < 0) {
perror("Failed to create a ruleset");
return 1;
}
- if (populate_ruleset(ENV_FS_RO_NAME, ruleset_fd, access_fs_ro)) {
+ if (populate_ruleset_fs(ENV_FS_RO_NAME, ruleset_fd, access_fs_ro)) {
+ goto err_close_ruleset;
+ }
+ if (populate_ruleset_fs(ENV_FS_RW_NAME, ruleset_fd, access_fs_rw)) {
+ goto err_close_ruleset;
+ }
+ if (populate_ruleset_net(ENV_TCP_BIND_NAME, ruleset_fd,
+ LANDLOCK_ACCESS_NET_BIND_TCP)) {
goto err_close_ruleset;
}
- if (populate_ruleset(ENV_FS_RW_NAME, ruleset_fd, access_fs_rw)) {
+ if (populate_ruleset_net(ENV_TCP_CONNECT_NAME, ruleset_fd,
+ LANDLOCK_ACCESS_NET_CONNECT_TCP)) {
goto err_close_ruleset;
}
if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
--
2.25.1
