diff mbox series

[bpf-next,v4,6/7] selftests/bpf: verify ca_name of struct mptcp_sock

Message ID 20220513224827.662254-7-mathew.j.martineau@linux.intel.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpf: mptcp: Support for mptcp_sock | expand

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Context Check Description
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 7 maintainers not CCed: kafai@fb.com john.fastabend@gmail.com shuah@kernel.org yhs@fb.com kpsingh@kernel.org linux-kselftest@vger.kernel.org songliubraving@fb.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 112 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-1 success Logs for Kernel LATEST on ubuntu-latest with gcc
bpf/vmtest-bpf-next-VM_Test-2 success Logs for Kernel LATEST on ubuntu-latest with llvm-15
bpf/vmtest-bpf-next-VM_Test-3 success Logs for Kernel LATEST on z15 with gcc

Commit Message

Mat Martineau May 13, 2022, 10:48 p.m. UTC 
From: Geliang Tang <geliang.tang@suse.com>

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)

Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
---
 tools/testing/selftests/bpf/bpf_tcp_helpers.h |  5 +++
 .../testing/selftests/bpf/prog_tests/mptcp.c  | 34 +++++++++++++++++++
 .../testing/selftests/bpf/progs/mptcp_sock.c  |  4 +++
 3 files changed, 43 insertions(+)
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/bpf_tcp_helpers.h b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
index 422491872619..c38c66d5c1e6 100644
--- 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
diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
index ac98aa314123..2ff7f18ea0ce 100644
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -6,10 +6,15 @@ 
 #include "cgroup_helpers.h"
 #include "network_helpers.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 char monitor_log_path[64];
@@ -75,17 +80,40 @@  static __u32 get_msk_token(void)
 	return token;
 }
 
+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)
 {
 	char *msg = "MPTCP subflow socket";
 	int err, cfd = client_fd;
 	struct mptcp_storage val;
+	char ca_name[TCP_CA_NAME_MAX];
 	__u32 token;
 
 	token = get_msk_token();
 	if (!ASSERT_GT(token, 0, "Unexpected 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;
@@ -108,6 +136,12 @@  static int verify_msk(int map_fd, int client_fd)
 		err++;
 	}
 
+	if (strncmp(val.ca_name, ca_name, TCP_CA_NAME_MAX)) {
+		log_err("Unexpected mptcp_sock.ca_name %s != %s",
+			val.ca_name, ca_name);
+		err++;
+	}
+
 	return err;
 }
 
diff --git a/tools/testing/selftests/bpf/progs/mptcp_sock.c b/tools/testing/selftests/bpf/progs/mptcp_sock.c
index 4890130826c6..c36f2f6bd2f1 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_sock.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_sock.c
@@ -2,6 +2,7 @@ 
 /* Copyright (c) 2020, Tessares SA. */
 /* Copyright (c) 2022, SUSE. */
 
+#include <string.h>
 #include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>
 #include "bpf_tcp_helpers.h"
@@ -13,6 +14,7 @@  struct mptcp_storage {
 	__u32 invoked;
 	__u32 is_mptcp;
 	__u32 token;
+	char ca_name[TCP_CA_NAME_MAX];
 };
 
 struct {
@@ -51,6 +53,7 @@  int _sockops(struct bpf_sock_ops *ctx)
 			return 1;
 
 		storage->token = 0;
+		bzero(storage->ca_name, TCP_CA_NAME_MAX);
 	} else {
 		if (!CONFIG_MPTCP)
 			return 1;
@@ -65,6 +68,7 @@  int _sockops(struct bpf_sock_ops *ctx)
 			return 1;
 
 		storage->token = msk->token;
+		memcpy(storage->ca_name, msk->ca_name, TCP_CA_NAME_MAX);
 	}
 	storage->invoked++;
 	storage->is_mptcp = is_mptcp;