From f7c6cb1d9728dea9d9f131ef57303d6821afb0f8 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Tue, 28 Jul 2020 17:31:03 -0700 Subject: [PATCH] bpf: Expose socket storage to BPF_PROG_TYPE_CGROUP_SOCK 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 Signed-off-by: Daniel Borkmann Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20200729003104.1280813-1-sdf@google.com --- 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 eafcd15..d3377c9 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 29e34551..7124f0f 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); } -- 2.7.4