[PATCH bpf-next 1/2] bpf: expose socket storage to BPF_PROG_TYPE_CGROUP_SOCK
From: Stanislav Fomichev <hidden>
Date: 2020-07-29 00:31:08
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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. Cc: Martin KaFai Lau <redacted> Signed-off-by: Stanislav Fomichev <redacted> --- net/core/bpf_sk_storage.c | 10 ++++++++++ net/core/filter.c | 3 +++ 2 files changed, 13 insertions(+)
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index eafcd15e7dfd..d3377c90a291 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c@@ -944,6 +944,16 @@ const struct bpf_func_proto bpf_sk_storage_get_proto = { .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,
diff --git a/net/core/filter.c b/net/core/filter.c
index 29e3455122f7..7124f0fe6974 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -6187,6 +6187,7 @@ bool bpf_helper_changes_pkt_data(void *func) } 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 func_id, const struct bpf_prog *prog) 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); }
--
2.28.0.163.g6104cc2f0b6-goog