[PATCH v8 bpf-next/net 4/6] bpf: Support bpf_setsockopt() for BPF_CGROUP_INET_SOCK_CREATE.
From: Kuniyuki Iwashima <kuniyu@google.com>
Date: 2025-09-10 19:21:08
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
We will support flagging SK_MEMCG_EXCLUSIVE via 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@google.com>
---
v5: Rename new variants to bpf_sock_create_{get,set}sockopt().
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..31b259f02ee9 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_sock_create_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_sock_create_setsockopt_proto = { + .func = bpf_sock_create_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_sock_create_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_sock_create_getsockopt_proto = { + .func = bpf_sock_create_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_sock_create_setsockopt_proto; + default: + return NULL; + } + case BPF_FUNC_getsockopt: + switch (prog->expected_attach_type) { + case BPF_CGROUP_INET_SOCK_CREATE: + return &bpf_sock_create_getsockopt_proto; + default: + return NULL; + } default: return bpf_base_func_proto(func_id, prog); }
--
2.51.0.384.g4c02a37b29-goog