Adding selftests for new added functionality to call bpf_setsockopt and
bpf_getsockopt from setsockopt BPF programs
Test Details:
1. BPF Program
Checks for changes in IPV6_TCLASS(SOL_IPV6) via setsockopt
If the cca for the socket is not cubic do nothing
If the newly set value for IPV6_TCLASS is 45 (0x2d) (as per our usecase)
then change the cc from cubic to reno
2. User Space Program
Creates an AF_INET6 socket and set the cca for that to be "cubic"
Attach the program and set the IPV6_TCLASS to 0x2d using setsockopt
Verify the cca for the socket changed to reno
Signed-off-by: Prankur gupta <prankgup@xxxxxx>
---
tools/testing/selftests/bpf/bpf_tcp_helpers.h | 18 +++++
.../bpf/prog_tests/sockopt_qos_to_cc.c | 70 +++++++++++++++++++
.../selftests/bpf/progs/sockopt_qos_to_cc.c | 39 +++++++++++
3 files changed, 127 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/sockopt_qos_to_cc.c
create mode 100644 tools/testing/selftests/bpf/progs/sockopt_qos_to_cc.c
diff --git a/tools/testing/selftests/bpf/bpf_tcp_helpers.h b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
index 029589c008c9..c9f9bdad60c7 100644
--- a/tools/testing/selftests/bpf/bpf_tcp_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
@@ -12,6 +12,10 @@
SEC("struct_ops/"#name) \
BPF_PROG(name, args)
+#ifndef SOL_TCP
+#define SOL_TCP 6
+#endif
+
#define tcp_jiffies32 ((__u32)bpf_jiffies64())
struct sock_common {
@@ -203,6 +207,20 @@ static __always_inline bool tcp_is_cwnd_limited(const struct sock *sk)
return !!BPF_CORE_READ_BITFIELD(tp, is_cwnd_limited);
}
+static __always_inline bool tcp_cc_eq(const char *a, const char *b)
+{
+ int i;
+
+ for (i = 0; i < TCP_CA_NAME_MAX; i++) {
+ if (a[i] != b[i])
+ return false;
+ if (!a[i])
+ break;
+ }
+
+ return true;
+}
+
extern __u32 tcp_slow_start(struct tcp_sock *tp, __u32 acked) __ksym;
extern void tcp_cong_avoid_ai(struct tcp_sock *tp, __u32 w, __u32 acked) __ksym;
diff --git a/tools/testing/selftests/bpf/prog_tests/sockopt_qos_to_cc.c b/tools/testing/selftests/bpf/prog_tests/sockopt_qos_to_cc.c
new file mode 100644
index 000000000000..6b53b3cb8dad
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/sockopt_qos_to_cc.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+#include <test_progs.h>
+#include <netinet/tcp.h>
+#include "sockopt_qos_to_cc.skel.h"
+
+static void run_setsockopt_test(int cg_fd, int sock_fd)
+{
+ socklen_t optlen;
+ char cc[16]; /* TCP_CA_NAME_MAX */
+ int buf;
+ int err = -1;
+
+ buf = 0x2D;
+ err = setsockopt(sock_fd, SOL_IPV6, IPV6_TCLASS, &buf, sizeof(buf));
+ if (!ASSERT_OK(err, "setsockopt(sock_fd, IPV6_TCLASS)"))
+ return;
+
+ /* Verify the setsockopt cc change */
+ optlen = sizeof(cc);
+ err = getsockopt(sock_fd, SOL_TCP, TCP_CONGESTION, cc, &optlen);
+ if (!ASSERT_OK(err, "getsockopt(sock_fd, TCP_CONGESTION)"))
+ return;
+
+ if (!ASSERT_STREQ(cc, "reno", "getsockopt(sock_fd, TCP_CONGESTION)"))
+ return;
+}
+
+void test_sockopt_qos_to_cc(void)
+{
+ struct sockopt_qos_to_cc *skel;
+ char cc_cubic[16] = "cubic"; /* TCP_CA_NAME_MAX */
+ int cg_fd = -1;
+ int sock_fd = -1;
+ int err;
+
+ cg_fd = test__join_cgroup("/sockopt_qos_to_cc");
+ if (!ASSERT_GE(cg_fd, 0, "cg-join(sockopt_qos_to_cc)"))
+ return;
+
+ skel = sockopt_qos_to_cc__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "skel"))
+ goto done;
+
+ sock_fd = socket(AF_INET6, SOCK_STREAM, 0);
+ if (!ASSERT_GE(sock_fd, 0, "v6 socket open"))
+ goto done;
+
+ err = setsockopt(sock_fd, SOL_TCP, TCP_CONGESTION, &cc_cubic,
+ sizeof(cc_cubic));
+ if (!ASSERT_OK(err, "setsockopt(sock_fd, TCP_CONGESTION)"))
+ goto done;
+
+ skel->links.sockopt_qos_to_cc =
+ bpf_program__attach_cgroup(skel->progs.sockopt_qos_to_cc,
+ cg_fd);
+ if (!ASSERT_OK_PTR(skel->links.sockopt_qos_to_cc,
+ "prog_attach(sockopt_qos_to_cc)"))
+ goto done;
+
+ run_setsockopt_test(cg_fd, sock_fd);
+
+done:
+ if (sock_fd != -1)
+ close(sock_fd);
+ if (cg_fd != -1)
+ close(cg_fd);
+ /* destroy can take null and error pointer */
+ sockopt_qos_to_cc__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/sockopt_qos_to_cc.c b/tools/testing/selftests/bpf/progs/sockopt_qos_to_cc.c
new file mode 100644
index 000000000000..1bce83b6e3a7
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/sockopt_qos_to_cc.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+#include <string.h>
+#include <linux/tcp.h>
+#include <netinet/in.h>
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_tcp_helpers.h"
+
+char _license[] SEC("license") = "GPL";
+
+SEC("cgroup/setsockopt")
+int sockopt_qos_to_cc(struct bpf_sockopt *ctx)
+{
+ void *optval_end = ctx->optval_end;
+ int *optval = ctx->optval;
+ char buf[TCP_CA_NAME_MAX];
+ char cc_reno[TCP_CA_NAME_MAX] = "reno";
+ char cc_cubic[TCP_CA_NAME_MAX] = "cubic";
+
+ if (ctx->level != SOL_IPV6 || ctx->optname != IPV6_TCLASS)
+ return 1;
+
+ if (optval + 1 > optval_end)
+ return 0; /* EPERM, bounds check */
+
+ if (bpf_getsockopt(ctx->sk, SOL_TCP, TCP_CONGESTION, &buf, sizeof(buf)))
+ return 0;
+
+ if (!tcp_cc_eq(buf, cc_cubic))
+ return 0;
+
+ if (*optval == 0x2d) {
+ if (bpf_setsockopt(ctx->sk, SOL_TCP, TCP_CONGESTION, &cc_reno,
+ sizeof(cc_reno)))
+ return 0;
+ }
+ return 1;
+}
--
2.30.2
