diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/lsm_cgroup.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/lsm_cgroup.c b/tools/testing/selftests/bpf/progs/lsm_cgroup.c new file mode 100644 index 000000000000..4f2d60b87b75 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/lsm_cgroup.c @@ -0,0 +1,180 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "vmlinux.h" +#include "bpf_tracing_net.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +char _license[] SEC("license") = "GPL"; + +#ifndef AF_PACKET +#define AF_PACKET 17 +#endif + +#ifndef AF_UNIX +#define AF_UNIX 1 +#endif + +#ifndef EPERM +#define EPERM 1 +#endif + +struct { + __uint(type, BPF_MAP_TYPE_CGROUP_STORAGE); + __type(key, __u64); + __type(value, __u64); +} cgroup_storage SEC(".maps"); + +int called_socket_post_create; +int called_socket_post_create2; +int called_socket_bind; +int called_socket_bind2; +int called_socket_alloc; +int called_socket_clone; + +static __always_inline int test_local_storage(void) +{ + __u64 *val; + + val = bpf_get_local_storage(&cgroup_storage, 0); + if (!val) + return 0; + *val += 1; + + return 1; +} + +static __always_inline int real_create(struct socket *sock, int family, + int protocol) +{ + struct sock *sk; + int prio = 123; + + /* Reject non-tx-only AF_PACKET. */ + if (family == AF_PACKET && protocol != 0) + return 0; /* EPERM */ + + sk = sock->sk; + if (!sk) + return 1; + + /* The rest of the sockets get default policy. */ + if (bpf_setsockopt(sk, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 0; /* EPERM */ + + /* Make sure bpf_getsockopt is allowed and works. */ + prio = 0; + if (bpf_getsockopt(sk, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 0; /* EPERM */ + if (prio != 123) + return 0; /* EPERM */ + + /* Can access cgroup local storage. */ + if (!test_local_storage()) + return 0; /* EPERM */ + + return 1; +} + +/* __cgroup_bpf_run_lsm_socket */ +SEC("lsm_cgroup/socket_post_create") +int BPF_PROG(socket_post_create, struct socket *sock, int family, + int type, int protocol, int kern) +{ + called_socket_post_create++; + return real_create(sock, family, protocol); +} + +/* __cgroup_bpf_run_lsm_socket */ +SEC("lsm_cgroup/socket_post_create") +int BPF_PROG(socket_post_create2, struct socket *sock, int family, + int type, int protocol, int kern) +{ + called_socket_post_create2++; + return real_create(sock, family, protocol); +} + +static __always_inline int real_bind(struct socket *sock, + struct sockaddr *address, + int addrlen) +{ + struct sockaddr_ll sa = {}; + + if (sock->sk->__sk_common.skc_family != AF_PACKET) + return 1; + + if (sock->sk->sk_kern_sock) + return 1; + + bpf_probe_read_kernel(&sa, sizeof(sa), address); + if (sa.sll_protocol) + return 0; /* EPERM */ + + /* Can access cgroup local storage. */ + if (!test_local_storage()) + return 0; /* EPERM */ + + return 1; +} + +/* __cgroup_bpf_run_lsm_socket */ +SEC("lsm_cgroup/socket_bind") +int BPF_PROG(socket_bind, struct socket *sock, struct sockaddr *address, + int addrlen) +{ + called_socket_bind++; + return real_bind(sock, address, addrlen); +} + +/* __cgroup_bpf_run_lsm_socket */ +SEC("lsm_cgroup/socket_bind") +int BPF_PROG(socket_bind2, struct socket *sock, struct sockaddr *address, + int addrlen) +{ + called_socket_bind2++; + return real_bind(sock, address, addrlen); +} + +/* __cgroup_bpf_run_lsm_current (via bpf_lsm_current_hooks) */ +SEC("lsm_cgroup/sk_alloc_security") +int BPF_PROG(socket_alloc, struct sock *sk, int family, gfp_t priority) +{ + called_socket_alloc++; + if (family == AF_UNIX) + return 0; /* EPERM */ + + /* Can access cgroup local storage. */ + if (!test_local_storage()) + return 0; /* EPERM */ + + return 1; +} + +/* __cgroup_bpf_run_lsm_sock */ +SEC("lsm_cgroup/inet_csk_clone") +int BPF_PROG(socket_clone, struct sock *newsk, const struct request_sock *req) +{ + int prio = 234; + + if (!newsk) + return 1; + + /* Accepted request sockets get a different priority. */ + if (bpf_setsockopt(newsk, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 1; + + /* Make sure bpf_getsockopt is allowed and works. */ + prio = 0; + if (bpf_getsockopt(newsk, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 1; + if (prio != 234) + return 1; + + /* Can access cgroup local storage. */ + if (!test_local_storage()) + return 1; + + called_socket_clone++; + + return 1; +} |