* [PATCH bpf-next v4 1/2] bpf: Fix bpf_get/setsockopt to tos for ipv4-mapped ipv6 socket
2026-06-13 16:24 [PATCH bpf-next v4 0/2] bpf: Fix bpf_get/setsockopt to tos for ipv4-mapped ipv6 socket Leon Hwang
@ 2026-06-13 16:24 ` Leon Hwang
2026-06-13 17:07 ` bot+bpf-ci
2026-06-13 16:24 ` [PATCH bpf-next v4 2/2] selftests/bpf: Add test to verify the fix for bpf_setsockopt() helper Leon Hwang
1 sibling, 1 reply; 4+ messages in thread
From: Leon Hwang @ 2026-06-13 16:24 UTC (permalink / raw)
To: bpf
Cc: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Eduard Zingerman, Kumar Kartikeya Dwivedi, Martin KaFai Lau,
Song Liu, Yonghong Song, Jiri Olsa, Emil Tsalapatis,
John Fastabend, Stanislav Fomichev, David S . Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, Simon Horman,
Shuah Khan, Leon Hwang, Ihor Solodrai, netdev, linux-kernel,
linux-kselftest, kernel-patches-bot, Feng Zhou
When TCP over IPv4 via INET6 API, bpf_get/setsockopt with ipv4 will
fail, because sk->sk_family is AF_INET6. With ipv6 will success, not
take effect, because inet_csk(sk)->icsk_af_ops is ipv6_mapped and
use ip_queue_xmit, inet_sk(sk)->tos.
To relax this restriction, allow getting/setting tos for those possible
ipv4-mapped ipv6 sockets.
Fixes: ee7f1e1302f5 ("bpf: Change bpf_setsockopt(SOL_IP) to reuse do_ip_setsockopt()")
Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
---
net/core/filter.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/net/core/filter.c b/net/core/filter.c
index 9590877b0714..57b00c6cc8cc 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5544,11 +5544,24 @@ static int sol_tcp_sockopt(struct sock *sk, int optname,
KERNEL_SOCKPTR(optval), *optlen);
}
+static bool sk_allows_sol_ip_sockopt(struct sock *sk)
+{
+ switch (sk->sk_family) {
+ case AF_INET:
+ return true;
+ case AF_INET6:
+ /* Allow getting/setting sockopt for possible ipv4-mapped ipv6 socket. */
+ return sk->sk_type != SOCK_RAW && !ipv6_only_sock(sk);
+ default:
+ return false;
+ }
+}
+
static int sol_ip_sockopt(struct sock *sk, int optname,
char *optval, int *optlen,
bool getopt)
{
- if (sk->sk_family != AF_INET)
+ if (!sk_allows_sol_ip_sockopt(sk))
return -EINVAL;
switch (optname) {
--
2.54.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH bpf-next v4 2/2] selftests/bpf: Add test to verify the fix for bpf_setsockopt() helper
2026-06-13 16:24 [PATCH bpf-next v4 0/2] bpf: Fix bpf_get/setsockopt to tos for ipv4-mapped ipv6 socket Leon Hwang
2026-06-13 16:24 ` [PATCH bpf-next v4 1/2] " Leon Hwang
@ 2026-06-13 16:24 ` Leon Hwang
1 sibling, 0 replies; 4+ messages in thread
From: Leon Hwang @ 2026-06-13 16:24 UTC (permalink / raw)
To: bpf
Cc: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Eduard Zingerman, Kumar Kartikeya Dwivedi, Martin KaFai Lau,
Song Liu, Yonghong Song, Jiri Olsa, Emil Tsalapatis,
John Fastabend, Stanislav Fomichev, David S . Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, Simon Horman,
Shuah Khan, Leon Hwang, Ihor Solodrai, netdev, linux-kernel,
linux-kselftest, kernel-patches-bot
Verify the fix by:
1. Attach cgroup sockops prog.
2. Build a tcp connection using ipv4 addr in ipv6 socket.
3. Verify the return value of bpf_setsockopt() helper.
Assisted-by: Codex:gpt-5.5-xhigh
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
---
.../selftests/bpf/prog_tests/setget_sockopt.c | 78 +++++++++++++++++++
.../selftests/bpf/progs/setget_sockopt.c | 23 ++++++
2 files changed, 101 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/setget_sockopt.c b/tools/testing/selftests/bpf/prog_tests/setget_sockopt.c
index 77fe1bfb7504..4e91d9b615ce 100644
--- a/tools/testing/selftests/bpf/prog_tests/setget_sockopt.c
+++ b/tools/testing/selftests/bpf/prog_tests/setget_sockopt.c
@@ -199,6 +199,83 @@ static void test_nonstandard_opt(int family)
bpf_link__destroy(getsockopt_link);
}
+static int connect_to_v4mapped_v6_fd(int server_fd)
+{
+ struct sockaddr_storage addr;
+ struct sockaddr_in *addr4 = (void *)&addr;
+ socklen_t addrlen = sizeof(addr);
+ struct sockaddr_in6 addr6 = {};
+ int fd = -1, v6only = 0, err;
+
+ err = getsockname(server_fd, (struct sockaddr *)&addr, &addrlen);
+ if (!ASSERT_OK(err, "getsockname"))
+ return -1;
+
+ fd = socket(AF_INET6, SOCK_STREAM, 0);
+ if (!ASSERT_GE(fd, 0, "socket"))
+ return -1;
+
+ err = settimeo(fd, 0);
+ if (!ASSERT_OK(err, "settimeo"))
+ goto err_out;
+
+ err = setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &v6only, sizeof(v6only));
+ if (!ASSERT_OK(err, "clear_v6only"))
+ goto err_out;
+
+ addr6.sin6_family = AF_INET6;
+ addr6.sin6_port = addr4->sin_port;
+ addr6.sin6_addr.s6_addr[10] = 0xff;
+ addr6.sin6_addr.s6_addr[11] = 0xff;
+ memcpy(&addr6.sin6_addr.s6_addr[12], &addr4->sin_addr, sizeof(addr4->sin_addr));
+
+ err = connect(fd, (struct sockaddr *)&addr6, sizeof(addr6));
+ if (!ASSERT_OK(err, "connect"))
+ goto err_out;
+
+ return fd;
+
+err_out:
+ close(fd);
+ return -1;
+}
+
+static void test_v4mapped_v6_ip_tos(void)
+{
+ struct setget_sockopt__bss *bss = skel->bss;
+ int sfd = -1, fd = -1, got = 0, exp = 0x1c;
+ socklen_t optlen;
+
+ memset(bss, 0, sizeof(*bss));
+ bss->v4mapped_v6_ip_tos_enable = 1;
+ bss->v4mapped_v6_ip_tos_ret = -1;
+ bss->v4mapped_v6_ip_tos_val = exp;
+
+ sfd = start_server(AF_INET, SOCK_STREAM, addr4_str, 0, 0);
+ if (!ASSERT_GE(sfd, 0, "start_server"))
+ goto err_out;
+
+ fd = connect_to_v4mapped_v6_fd(sfd);
+ if (!ASSERT_GE(fd, 0, "connect_to_v4mapped_v6_fd"))
+ goto err_out;
+
+ ASSERT_GT(bss->v4mapped_v6_ip_tos_cnt, 0, "v4mapped_v6_ip_tos_cnt");
+ ASSERT_EQ(bss->v4mapped_v6_ip_tos_ret, 0, "v4mapped_v6_ip_tos_ret");
+
+ optlen = sizeof(got);
+ if (!ASSERT_OK(getsockopt(fd, SOL_IP, IP_TOS, &got, &optlen), "getsockopt_ip_tos"))
+ goto err_out;
+
+ ASSERT_EQ(got, exp, "ip_tos");
+
+err_out:
+ bss->v4mapped_v6_ip_tos_enable = 0;
+ if (fd >= 0)
+ close(fd);
+ if (sfd >= 0)
+ close(sfd);
+}
+
void test_setget_sockopt(void)
{
cg_fd = test__join_cgroup(CG_NAME);
@@ -238,6 +315,7 @@ void test_setget_sockopt(void)
test_ktls(AF_INET);
test_nonstandard_opt(AF_INET);
test_nonstandard_opt(AF_INET6);
+ test_v4mapped_v6_ip_tos();
done:
setget_sockopt__destroy(skel);
diff --git a/tools/testing/selftests/bpf/progs/setget_sockopt.c b/tools/testing/selftests/bpf/progs/setget_sockopt.c
index d330b1511979..636a7cd8e2fa 100644
--- a/tools/testing/selftests/bpf/progs/setget_sockopt.c
+++ b/tools/testing/selftests/bpf/progs/setget_sockopt.c
@@ -387,6 +387,24 @@ int _getsockopt(struct bpf_sockopt *ctx)
return 1;
}
+int v4mapped_v6_ip_tos_enable;
+int v4mapped_v6_ip_tos_ret;
+int v4mapped_v6_ip_tos_cnt;
+int v4mapped_v6_ip_tos_val;
+
+static void test_v4mapped_v6_ip_tos(struct bpf_sock_ops *skops)
+{
+ int tos = v4mapped_v6_ip_tos_val;
+
+ if (!v4mapped_v6_ip_tos_enable || skops->op != BPF_SOCK_OPS_TCP_CONNECT_CB)
+ return;
+ if (skops->family != AF_INET6)
+ return;
+
+ v4mapped_v6_ip_tos_cnt++;
+ v4mapped_v6_ip_tos_ret = bpf_setsockopt(skops, IPPROTO_IP, IP_TOS, &tos, sizeof(tos));
+}
+
SEC("sockops")
int skops_sockopt(struct bpf_sock_ops *skops)
{
@@ -401,6 +419,11 @@ int skops_sockopt(struct bpf_sock_ops *skops)
if (!sk)
return 1;
+ if (v4mapped_v6_ip_tos_enable) {
+ test_v4mapped_v6_ip_tos(skops);
+ return 1;
+ }
+
switch (skops->op) {
case BPF_SOCK_OPS_TCP_LISTEN_CB:
nr_listen += !(bpf_test_sockopt(skops, sk) ||
--
2.54.0
^ permalink raw reply related [flat|nested] 4+ messages in thread