We will store a flag in sk->sk_memcg by bpf_setsockopt() at the
BPF_CGROUP_INET_SOCK_CREATE hook.
BPF_CGROUP_INET_SOCK_CREATE is invoked by __cgroup_bpf_run_filter_sk()
that passes a pointer to struct sock to the bpf prog as void *ctx.
But there are no bpf_func_proto for bpf_setsockopt() that receives
the ctx as a pointer to struct sock.
Also, bpf_getsockopt() will be necessary for a cgroup with multiple
bpf progs running.
Let's add new bpf_setsockopt() and bpf_getsockopt() variants for
BPF_CGROUP_INET_SOCK_CREATE.
Note that inet_create() is not under lock_sock() and has the same
semantics with bpf_lsm_unlocked_sockopt_hooks.
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
---
v4:
* Use __bpf_setsockopt() instead of _bpf_setsockopt()
* Add getsockopt() for a cgroup with multiple bpf progs running
v3: Remove bpf_func_proto for accept()
v2: Make 2 new bpf_func_proto static
---
net/core/filter.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 48 insertions(+)
diff --git a/net/core/filter.c b/net/core/filter.c
index 63f3baee2daf..b6d514039cf8 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5723,6 +5723,40 @@ static const struct bpf_func_proto bpf_sock_addr_getsockopt_proto = {
.arg5_type = ARG_CONST_SIZE,
};
+BPF_CALL_5(bpf_unlocked_sock_setsockopt, struct sock *, sk, int, level,
+ int, optname, char *, optval, int, optlen)
+{
+ return __bpf_setsockopt(sk, level, optname, optval, optlen);
+}
+
+static const struct bpf_func_proto bpf_unlocked_sock_setsockopt_proto = {
+ .func = bpf_unlocked_sock_setsockopt,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_ANYTHING,
+ .arg3_type = ARG_ANYTHING,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
+ .arg5_type = ARG_CONST_SIZE,
+};
+
+BPF_CALL_5(bpf_unlocked_sock_getsockopt, struct sock *, sk, int, level,
+ int, optname, char *, optval, int, optlen)
+{
+ return __bpf_getsockopt(sk, level, optname, optval, optlen);
+}
+
+static const struct bpf_func_proto bpf_unlocked_sock_getsockopt_proto = {
+ .func = bpf_unlocked_sock_getsockopt,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_ANYTHING,
+ .arg3_type = ARG_ANYTHING,
+ .arg4_type = ARG_PTR_TO_UNINIT_MEM,
+ .arg5_type = ARG_CONST_SIZE,
+};
+
BPF_CALL_5(bpf_sock_ops_setsockopt, struct bpf_sock_ops_kern *, bpf_sock,
int, level, int, optname, char *, optval, int, optlen)
{
@@ -8051,6 +8085,20 @@ sock_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_sk_storage_get_cg_sock_proto;
case BPF_FUNC_ktime_get_coarse_ns:
return &bpf_ktime_get_coarse_ns_proto;
+ case BPF_FUNC_setsockopt:
+ switch (prog->expected_attach_type) {
+ case BPF_CGROUP_INET_SOCK_CREATE:
+ return &bpf_unlocked_sock_setsockopt_proto;
+ default:
+ return NULL;
+ }
+ case BPF_FUNC_getsockopt:
+ switch (prog->expected_attach_type) {
+ case BPF_CGROUP_INET_SOCK_CREATE:
+ return &bpf_unlocked_sock_getsockopt_proto;
+ default:
+ return NULL;
+ }
default:
return bpf_base_func_proto(func_id, prog);
}
--
2.51.0.318.gd7df087d1a-goog
