@@ -58,6 +58,9 @@ static inline int landlock_restrict_self(const int ruleset_fd,
#define ENV_TCP_BIND_NAME "LL_TCP_BIND"
#define ENV_TCP_CONNECT_NAME "LL_TCP_CONNECT"
#define ENV_SCOPED_NAME "LL_SCOPED"
+#define ENV_UDP_BIND_NAME "LL_UDP_BIND"
+#define ENV_UDP_CONNECT_NAME "LL_UDP_CONNECT"
+#define ENV_UDP_SENDTO_NAME "LL_UDP_SENDTO"
#define ENV_DELIMITER ":"
static int str2num(const char *numstr, __u64 *num_dst)
@@ -288,7 +291,7 @@ static bool check_ruleset_scope(const char *const env_var,
/* clang-format on */
-#define LANDLOCK_ABI_LAST 6
+#define LANDLOCK_ABI_LAST 7
#define XSTR(s) #s
#define STR(s) XSTR(s)
@@ -311,6 +314,11 @@ static const char help[] =
"means an empty list):\n"
"* " ENV_TCP_BIND_NAME ": ports allowed to bind (server)\n"
"* " ENV_TCP_CONNECT_NAME ": ports allowed to connect (client)\n"
+ "* " ENV_UDP_BIND_NAME ": UDP ports allowed to bind (client: set as "
+ "source port / server: prepare to listen on port)\n"
+ "* " ENV_UDP_CONNECT_NAME ": UDP ports allowed to connect (client: "
+ "set as destination port / server: only receive from one client)\n"
+ "* " ENV_UDP_SENDTO_NAME ": UDP ports allowed to send to (client/server)\n"
"* " ENV_SCOPED_NAME ": actions denied on the outside of the landlock domain\n"
" - \"a\" to restrict opening abstract unix sockets\n"
" - \"s\" to restrict sending signals\n"
@@ -320,6 +328,8 @@ static const char help[] =
ENV_FS_RW_NAME "=\"/dev/null:/dev/full:/dev/zero:/dev/pts:/tmp\" "
ENV_TCP_BIND_NAME "=\"9418\" "
ENV_TCP_CONNECT_NAME "=\"80:443\" "
+ ENV_UDP_CONNECT_NAME "=\"53\" "
+ ENV_UDP_SENDTO_NAME "=\"53\" "
ENV_SCOPED_NAME "=\"a:s\" "
"%1$s bash -i\n"
"\n"
@@ -340,7 +350,10 @@ int main(const int argc, char *const argv[], char *const *const envp)
struct landlock_ruleset_attr ruleset_attr = {
.handled_access_fs = access_fs_rw,
.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
- LANDLOCK_ACCESS_NET_CONNECT_TCP,
+ LANDLOCK_ACCESS_NET_CONNECT_TCP |
+ LANDLOCK_ACCESS_NET_BIND_UDP |
+ LANDLOCK_ACCESS_NET_CONNECT_UDP |
+ LANDLOCK_ACCESS_NET_SENDTO_UDP,
.scoped = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
LANDLOCK_SCOPE_SIGNAL,
};
@@ -415,6 +428,14 @@ int main(const int argc, char *const argv[], char *const *const envp)
/* Removes LANDLOCK_SCOPE_* for ABI < 6 */
ruleset_attr.scoped &= ~(LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
LANDLOCK_SCOPE_SIGNAL);
+
+ __attribute__((fallthrough));
+ case 6:
+ /* Removes UDP support for ABI < 7 */
+ ruleset_attr.handled_access_fs &=
+ ~(LANDLOCK_ACCESS_NET_BIND_UDP |
+ LANDLOCK_ACCESS_NET_CONNECT_UDP |
+ LANDLOCK_ACCESS_NET_SENDTO_UDP);
fprintf(stderr,
"Hint: You should update the running kernel "
"to leverage Landlock features "
@@ -445,6 +466,27 @@ int main(const int argc, char *const argv[], char *const *const envp)
ruleset_attr.handled_access_net &=
~LANDLOCK_ACCESS_NET_CONNECT_TCP;
}
+ /* Removes UDP bind access control if not supported by a user */
+ env_port_name = getenv(ENV_UDP_BIND_NAME);
+ if (!env_port_name) {
+ ruleset_attr.handled_access_net &=
+ ~LANDLOCK_ACCESS_NET_BIND_UDP;
+ }
+ /* Removes UDP connect access control if not supported by a user */
+ env_port_name = getenv(ENV_UDP_CONNECT_NAME);
+ if (!env_port_name) {
+ ruleset_attr.handled_access_net &=
+ ~LANDLOCK_ACCESS_NET_CONNECT_UDP;
+ }
+ /*
+ * Removes UDP sendmsg(addr != NULL) access control if not
+ * supported by a user
+ */
+ env_port_name = getenv(ENV_UDP_SENDTO_NAME);
+ if (!env_port_name) {
+ ruleset_attr.handled_access_net &=
+ ~LANDLOCK_ACCESS_NET_SENDTO_UDP;
+ }
if (check_ruleset_scope(ENV_SCOPED_NAME, &ruleset_attr))
return 1;
@@ -471,6 +513,18 @@ int main(const int argc, char *const argv[], char *const *const envp)
LANDLOCK_ACCESS_NET_CONNECT_TCP)) {
goto err_close_ruleset;
}
+ if (populate_ruleset_net(ENV_UDP_BIND_NAME, ruleset_fd,
+ LANDLOCK_ACCESS_NET_BIND_UDP)) {
+ goto err_close_ruleset;
+ }
+ if (populate_ruleset_net(ENV_UDP_CONNECT_NAME, ruleset_fd,
+ LANDLOCK_ACCESS_NET_CONNECT_UDP)) {
+ goto err_close_ruleset;
+ }
+ if (populate_ruleset_net(ENV_UDP_SENDTO_NAME, ruleset_fd,
+ LANDLOCK_ACCESS_NET_SENDTO_UDP)) {
+ goto err_close_ruleset;
+ }
if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
perror("Failed to restrict privileges");
Add environment variables to control associated access rights: (each one takes a list of ports separated by colons, like other list options) - LL_UDP_BIND - LL_UDP_CONNECT - LL_UDP_SENDTO Signed-off-by: Matthieu Buffet <matthieu@buffet.re> --- samples/landlock/sandboxer.c | 58 ++++++++++++++++++++++++++++++++++-- 1 file changed, 56 insertions(+), 2 deletions(-)