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From: Lorenz Bauer <lmb@cloudflare.com>
To: ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org,
	bpf@vger.kernel.org
Cc: kafai@fb.com, Lorenz Bauer <lmb@cloudflare.com>
Subject: [PATCH v2 2/8] bpf: allow helpers to return PTR_TO_SOCK_COMMON
Date: Tue, 19 Mar 2019 10:20:57 +0000	[thread overview]
Message-ID: <20190319102103.7380-3-lmb@cloudflare.com> (raw)
In-Reply-To: <20190319102103.7380-1-lmb@cloudflare.com>

It's currently not possible to access timewait or request sockets
from eBPF, since there is no way to return a PTR_TO_SOCK_COMMON
from a helper. Introduce RET_PTR_TO_SOCK_COMMON to enable this
behaviour.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
---
 include/linux/bpf.h   | 1 +
 kernel/bpf/verifier.c | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index f02367faa58d..f62897198844 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -205,6 +205,7 @@ enum bpf_return_type {
 	RET_PTR_TO_MAP_VALUE_OR_NULL,	/* returns a pointer to map elem value or NULL */
 	RET_PTR_TO_SOCKET_OR_NULL,	/* returns a pointer to a socket or NULL */
 	RET_PTR_TO_TCP_SOCK_OR_NULL,	/* returns a pointer to a tcp_sock or NULL */
+	RET_PTR_TO_SOCK_COMMON_OR_NULL,	/* returns a pointer to a sock_common or NULL */
 };
 
 /* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index a52e723c8e5d..f60d9df4e00a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3148,6 +3148,10 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
 		mark_reg_known_zero(env, regs, BPF_REG_0);
 		regs[BPF_REG_0].type = PTR_TO_SOCKET_OR_NULL;
 		regs[BPF_REG_0].id = ++env->id_gen;
+	} else if (fn->ret_type == RET_PTR_TO_SOCK_COMMON_OR_NULL) {
+		mark_reg_known_zero(env, regs, BPF_REG_0);
+		regs[BPF_REG_0].type = PTR_TO_SOCK_COMMON_OR_NULL;
+		regs[BPF_REG_0].id = ++env->id_gen;
 	} else if (fn->ret_type == RET_PTR_TO_TCP_SOCK_OR_NULL) {
 		mark_reg_known_zero(env, regs, BPF_REG_0);
 		regs[BPF_REG_0].type = PTR_TO_TCP_SOCK_OR_NULL;
-- 
2.19.1


  parent reply	other threads:[~2019-03-19 10:21 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20190222095057.9442-1-lmb@cloudflare.com>
2019-03-14 11:39 ` [PATCH v2 0/8] Allow checking SYN cookies from XDP and tc cls act Lorenz Bauer
2019-03-14 11:39   ` [PATCH v2 1/8] bpf: track references based on is_acquire_func Lorenz Bauer
2019-03-14 11:39   ` [PATCH v2 2/8] bpf: allow helpers to return PTR_TO_SOCK_COMMON Lorenz Bauer
2019-03-14 11:39   ` [PATCH v2 3/8] bpf: add skc_lookup_tcp helper Lorenz Bauer
2019-03-14 11:39   ` [PATCH v2 4/8] bpf: add helper to check for a valid SYN cookie Lorenz Bauer
2019-03-14 11:39   ` [PATCH v2 5/8] tools: update include/uapi/linux/bpf.h Lorenz Bauer
2019-03-14 11:39   ` [PATCH v2 6/8] selftests/bpf: allow specifying helper for BPF_SK_LOOKUP Lorenz Bauer
2019-03-14 11:39   ` [PATCH v2 7/8] selftests/bpf: test references to sock_common Lorenz Bauer
2019-03-14 11:39   ` [PATCH v2 8/8] selftests/bpf: add tests for bpf_tcp_check_syncookie and bpf_skc_lookup_tcp Lorenz Bauer
2019-03-15 20:42   ` [PATCH v2 0/8] Allow checking SYN cookies from XDP and tc cls act Alexei Starovoitov
2019-03-19 10:20 ` Lorenz Bauer
2019-03-19 10:20   ` [PATCH v2 1/8] bpf: track references based on is_acquire_func Lorenz Bauer
2019-03-19 10:20   ` Lorenz Bauer [this message]
2019-03-19 10:20   ` [PATCH v2 3/8] bpf: add skc_lookup_tcp helper Lorenz Bauer
2019-03-19 21:30     ` Alexei Starovoitov
2019-03-19 10:20   ` [PATCH v2 4/8] bpf: add helper to check for a valid SYN cookie Lorenz Bauer
2019-03-19 22:17     ` Alexei Starovoitov
2019-03-21  2:09       ` Lorenz Bauer
2019-03-21  3:03         ` Alexei Starovoitov
2019-03-21  4:53           ` Lorenz Bauer
2019-03-21  5:50             ` Alexei Starovoitov
2019-03-19 10:21   ` [PATCH v2 5/8] tools: update include/uapi/linux/bpf.h Lorenz Bauer
2019-03-19 10:21   ` [PATCH v2 6/8] selftests/bpf: allow specifying helper for BPF_SK_LOOKUP Lorenz Bauer
2019-03-19 10:21   ` [PATCH v2 7/8] selftests/bpf: test references to sock_common Lorenz Bauer
2019-03-19 10:21   ` [PATCH v2 8/8] selftests/bpf: add tests for bpf_tcp_check_syncookie and bpf_skc_lookup_tcp Lorenz Bauer
2019-03-22  1:53   ` [PATCH bpf-next v3 0/8] Allow checking SYN cookies from XDP and tc cls act Lorenz Bauer
2019-03-22  1:53     ` [PATCH bpf-next v3 1/8] bpf: track references based on is_acquire_func Lorenz Bauer
2019-03-22  1:54     ` [PATCH bpf-next v3 2/8] bpf: allow helpers to return PTR_TO_SOCK_COMMON Lorenz Bauer
2019-03-22  1:54     ` [PATCH bpf-next v3 3/8] bpf: add skc_lookup_tcp helper Lorenz Bauer
2019-03-22  1:54     ` [PATCH bpf-next v3 4/8] bpf: add helper to check for a valid SYN cookie Lorenz Bauer
2019-03-22  2:06       ` Alexei Starovoitov
2019-03-22  2:52         ` Lorenz Bauer
2019-03-22  1:54     ` [PATCH bpf-next v3 5/8] tools: update include/uapi/linux/bpf.h Lorenz Bauer
2019-03-22  1:54     ` [PATCH bpf-next v3 6/8] selftests/bpf: allow specifying helper for BPF_SK_LOOKUP Lorenz Bauer
2019-03-22  1:54     ` [PATCH bpf-next v3 7/8] selftests/bpf: test references to sock_common Lorenz Bauer
2019-03-22  1:54     ` [PATCH bpf-next v3 8/8] selftests/bpf: add tests for bpf_tcp_check_syncookie and bpf_skc_lookup_tcp Lorenz Bauer

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