From: Stanislav Fomichev <sdf@google.com>
Date: Tue, 28 Jul 2020 17:31:03 -0700
Subject: bpf: Expose socket storage to BPF_PROG_TYPE_CGROUP_SOCK
Patch-mainline: v5.9-rc1
Git-commit: f7c6cb1d9728dea9d9f131ef57303d6821afb0f8
References: bsc#1177028
This lets us use socket storage from the following hooks:
* BPF_CGROUP_INET_SOCK_CREATE
* BPF_CGROUP_INET_SOCK_RELEASE
* BPF_CGROUP_INET4_POST_BIND
* BPF_CGROUP_INET6_POST_BIND
Using existing 'bpf_sk_storage_get_proto' doesn't work because
second argument is ARG_PTR_TO_SOCKET. Even though
BPF_PROG_TYPE_CGROUP_SOCK hooks operate on 'struct bpf_sock',
the verifier still considers it as a PTR_TO_CTX.
That's why I'm adding another 'bpf_sk_storage_get_cg_sock_proto'
definition strictly for BPF_PROG_TYPE_CGROUP_SOCK which accepts
ARG_PTR_TO_CTX which is really 'struct sock' for this program type.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200729003104.1280813-1-sdf@google.com
Acked-by: Gary Lin <glin@suse.com>
---
net/core/bpf_sk_storage.c | 10 ++++++++++
net/core/filter.c | 3 +++
2 files changed, 13 insertions(+)
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -911,6 +911,16 @@ const struct bpf_func_proto bpf_sk_stora
.arg4_type = ARG_ANYTHING,
};
+const struct bpf_func_proto bpf_sk_storage_get_cg_sock_proto = {
+ .func = bpf_sk_storage_get,
+ .gpl_only = false,
+ .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
+ .arg1_type = ARG_CONST_MAP_PTR,
+ .arg2_type = ARG_PTR_TO_CTX, /* context is 'struct sock' */
+ .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
+ .arg4_type = ARG_ANYTHING,
+};
+
const struct bpf_func_proto bpf_sk_storage_delete_proto = {
.func = bpf_sk_storage_delete,
.gpl_only = false,
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6187,6 +6187,7 @@ bool bpf_helper_changes_pkt_data(void *f
}
const struct bpf_func_proto bpf_event_output_data_proto __weak;
+const struct bpf_func_proto bpf_sk_storage_get_cg_sock_proto __weak;
static const struct bpf_func_proto *
sock_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
@@ -6219,6 +6220,8 @@ sock_filter_func_proto(enum bpf_func_id
case BPF_FUNC_get_cgroup_classid:
return &bpf_get_cgroup_classid_curr_proto;
#endif
+ case BPF_FUNC_sk_storage_get:
+ return &bpf_sk_storage_get_cg_sock_proto;
default:
return bpf_base_func_proto(func_id);
}