From: Geliang Tang <geliang.tang@suse.com>
Date: Thu, 19 May 2022 16:30:15 -0700
Subject: selftests/bpf: Verify ca_name of struct mptcp_sock
Patch-mainline: v5.19-rc1
Git-commit: ccc090f469000fd757049028eeb0dff43013f7c1
References: jsc#PED-1377
This patch verifies another member of struct mptcp_sock, ca_name. Add a
new function get_msk_ca_name() to read the sysctl tcp_congestion_control
and verify it in verify_msk().
v3: Access the sysctl through the filesystem to avoid compatibility
issues with the busybox sysctl command.
v4: use ASSERT_* instead of CHECK_FAIL (Andrii)
v5: use ASSERT_STRNEQ() instead of strncmp() (Andrii)
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Link: https://lore.kernel.org/bpf/20220519233016.105670-7-mathew.j.martineau@linux.intel.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/testing/selftests/bpf/bpf_tcp_helpers.h | 5 ++++
tools/testing/selftests/bpf/prog_tests/mptcp.c | 31 +++++++++++++++++++++++++
tools/testing/selftests/bpf/progs/mptcp_sock.c | 3 ++
3 files changed, 39 insertions(+)
--- a/tools/testing/selftests/bpf/bpf_tcp_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
@@ -16,6 +16,10 @@ BPF_PROG(name, args)
#define SOL_TCP 6
#endif
+#ifndef TCP_CA_NAME_MAX
+#define TCP_CA_NAME_MAX 16
+#endif
+
#define tcp_jiffies32 ((__u32)bpf_jiffies64())
struct sock_common {
@@ -230,6 +234,7 @@ struct mptcp_sock {
struct inet_connection_sock sk;
__u32 token;
+ char ca_name[TCP_CA_NAME_MAX];
} __attribute__((preserve_access_index));
#endif
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -7,10 +7,15 @@
#include "network_helpers.h"
#include "mptcp_sock.skel.h"
+#ifndef TCP_CA_NAME_MAX
+#define TCP_CA_NAME_MAX 16
+#endif
+
struct mptcp_storage {
__u32 invoked;
__u32 is_mptcp;
__u32 token;
+ char ca_name[TCP_CA_NAME_MAX];
};
static int verify_tsk(int map_fd, int client_fd)
@@ -31,14 +36,37 @@ static int verify_tsk(int map_fd, int cl
return err;
}
+static void get_msk_ca_name(char ca_name[])
+{
+ size_t len;
+ int fd;
+
+ fd = open("/proc/sys/net/ipv4/tcp_congestion_control", O_RDONLY);
+ if (!ASSERT_GE(fd, 0, "failed to open tcp_congestion_control"))
+ return;
+
+ len = read(fd, ca_name, TCP_CA_NAME_MAX);
+ if (!ASSERT_GT(len, 0, "failed to read ca_name"))
+ goto err;
+
+ if (len > 0 && ca_name[len - 1] == '\n')
+ ca_name[len - 1] = '\0';
+
+err:
+ close(fd);
+}
+
static int verify_msk(int map_fd, int client_fd, __u32 token)
{
+ char ca_name[TCP_CA_NAME_MAX];
int err, cfd = client_fd;
struct mptcp_storage val;
if (!ASSERT_GT(token, 0, "invalid token"))
return -1;
+ get_msk_ca_name(ca_name);
+
err = bpf_map_lookup_elem(map_fd, &cfd, &val);
if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
return err;
@@ -52,6 +80,9 @@ static int verify_msk(int map_fd, int cl
if (!ASSERT_EQ(val.token, token, "unexpected token"))
err++;
+ if (!ASSERT_STRNEQ(val.ca_name, ca_name, TCP_CA_NAME_MAX, "unexpected ca_name"))
+ err++;
+
return err;
}
--- a/tools/testing/selftests/bpf/progs/mptcp_sock.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_sock.c
@@ -13,6 +13,7 @@ struct mptcp_storage {
__u32 invoked;
__u32 is_mptcp;
__u32 token;
+ char ca_name[TCP_CA_NAME_MAX];
};
struct {
@@ -51,6 +52,7 @@ int _sockops(struct bpf_sock_ops *ctx)
return 1;
storage->token = 0;
+ __builtin_memset(storage->ca_name, 0, TCP_CA_NAME_MAX);
} else {
msk = bpf_skc_to_mptcp_sock(sk);
if (!msk)
@@ -62,6 +64,7 @@ int _sockops(struct bpf_sock_ops *ctx)
return 1;
storage->token = msk->token;
+ __builtin_memcpy(storage->ca_name, msk->ca_name, TCP_CA_NAME_MAX);
}
storage->invoked++;
storage->is_mptcp = is_mptcp;