bpf: Relax tuple len requirement for sk helpers.

__bpf_skc_lookup() safely handles incorrect values of tuple len,
hence we can allow zero to be passed as tuple len.
This patch alone doesn't make an observable verifier difference.
It's a trivial improvement that might simplify bpf programs.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240613013815.953-2-alexei.starovoitov@gmail.com

diff --git a/net/core/filter.c b/net/core/filter.c
index 73722790cee34160504d437f99a08de5d1fdce7a..f1c37c85b8580aa44fc79b8f74ea7241cba4883d 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6815,7 +6815,7 @@ static const struct bpf_func_proto bpf_skc_lookup_tcp_proto = {
        .ret_type       = RET_PTR_TO_SOCK_COMMON_OR_NULL,
        .arg1_type      = ARG_PTR_TO_CTX,
        .arg2_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
-       .arg3_type      = ARG_CONST_SIZE,
+       .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type      = ARG_ANYTHING,
        .arg5_type      = ARG_ANYTHING,
 };
@@ -6834,7 +6834,7 @@ static const struct bpf_func_proto bpf_sk_lookup_tcp_proto = {
        .ret_type       = RET_PTR_TO_SOCKET_OR_NULL,
        .arg1_type      = ARG_PTR_TO_CTX,
        .arg2_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
-       .arg3_type      = ARG_CONST_SIZE,
+       .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type      = ARG_ANYTHING,
        .arg5_type      = ARG_ANYTHING,
 };
@@ -6853,7 +6853,7 @@ static const struct bpf_func_proto bpf_sk_lookup_udp_proto = {
        .ret_type       = RET_PTR_TO_SOCKET_OR_NULL,
        .arg1_type      = ARG_PTR_TO_CTX,
        .arg2_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
-       .arg3_type      = ARG_CONST_SIZE,
+       .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type      = ARG_ANYTHING,
        .arg5_type      = ARG_ANYTHING,
 };
@@ -6877,7 +6877,7 @@ static const struct bpf_func_proto bpf_tc_skc_lookup_tcp_proto = {
        .ret_type       = RET_PTR_TO_SOCK_COMMON_OR_NULL,
        .arg1_type      = ARG_PTR_TO_CTX,
        .arg2_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
-       .arg3_type      = ARG_CONST_SIZE,
+       .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type      = ARG_ANYTHING,
        .arg5_type      = ARG_ANYTHING,
 };
@@ -6901,7 +6901,7 @@ static const struct bpf_func_proto bpf_tc_sk_lookup_tcp_proto = {
        .ret_type       = RET_PTR_TO_SOCKET_OR_NULL,
        .arg1_type      = ARG_PTR_TO_CTX,
        .arg2_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
-       .arg3_type      = ARG_CONST_SIZE,
+       .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type      = ARG_ANYTHING,
        .arg5_type      = ARG_ANYTHING,
 };
@@ -6925,7 +6925,7 @@ static const struct bpf_func_proto bpf_tc_sk_lookup_udp_proto = {
        .ret_type       = RET_PTR_TO_SOCKET_OR_NULL,
        .arg1_type      = ARG_PTR_TO_CTX,
        .arg2_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
-       .arg3_type      = ARG_CONST_SIZE,
+       .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type      = ARG_ANYTHING,
        .arg5_type      = ARG_ANYTHING,
 };
@@ -6963,7 +6963,7 @@ static const struct bpf_func_proto bpf_xdp_sk_lookup_udp_proto = {
        .ret_type       = RET_PTR_TO_SOCKET_OR_NULL,
        .arg1_type      = ARG_PTR_TO_CTX,
        .arg2_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
-       .arg3_type      = ARG_CONST_SIZE,
+       .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type      = ARG_ANYTHING,
        .arg5_type      = ARG_ANYTHING,
 };
@@ -6987,7 +6987,7 @@ static const struct bpf_func_proto bpf_xdp_skc_lookup_tcp_proto = {
        .ret_type       = RET_PTR_TO_SOCK_COMMON_OR_NULL,
        .arg1_type      = ARG_PTR_TO_CTX,
        .arg2_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
-       .arg3_type      = ARG_CONST_SIZE,
+       .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type      = ARG_ANYTHING,
        .arg5_type      = ARG_ANYTHING,
 };
@@ -7011,7 +7011,7 @@ static const struct bpf_func_proto bpf_xdp_sk_lookup_tcp_proto = {
        .ret_type       = RET_PTR_TO_SOCKET_OR_NULL,
        .arg1_type      = ARG_PTR_TO_CTX,
        .arg2_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
-       .arg3_type      = ARG_CONST_SIZE,
+       .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type      = ARG_ANYTHING,
        .arg5_type      = ARG_ANYTHING,
 };
@@ -7031,7 +7031,7 @@ static const struct bpf_func_proto bpf_sock_addr_skc_lookup_tcp_proto = {
        .ret_type       = RET_PTR_TO_SOCK_COMMON_OR_NULL,
        .arg1_type      = ARG_PTR_TO_CTX,
        .arg2_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
-       .arg3_type      = ARG_CONST_SIZE,
+       .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type      = ARG_ANYTHING,
        .arg5_type      = ARG_ANYTHING,
 };
@@ -7050,7 +7050,7 @@ static const struct bpf_func_proto bpf_sock_addr_sk_lookup_tcp_proto = {
        .ret_type       = RET_PTR_TO_SOCKET_OR_NULL,
        .arg1_type      = ARG_PTR_TO_CTX,
        .arg2_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
-       .arg3_type      = ARG_CONST_SIZE,
+       .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type      = ARG_ANYTHING,
        .arg5_type      = ARG_ANYTHING,
 };
@@ -7069,7 +7069,7 @@ static const struct bpf_func_proto bpf_sock_addr_sk_lookup_udp_proto = {
        .ret_type       = RET_PTR_TO_SOCKET_OR_NULL,
        .arg1_type      = ARG_PTR_TO_CTX,
        .arg2_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
-       .arg3_type      = ARG_CONST_SIZE,
+       .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type      = ARG_ANYTHING,
        .arg5_type      = ARG_ANYTHING,
 };