Re: [PATCH 25/31] selftests/net: Add TCP-AO library

From: Shuah Khan
Date: Tue Aug 23 2022 - 13:49:23 EST


On 8/18/22 10:59 AM, Dmitry Safonov wrote:
Provide functions to create selftests dedicated to TCP-AO.
They can run in parallel, as they use temporary net namespaces.
They can be very specific to the feature being tested.
This will allow to create a lot of TCP-AO tests, without complicating
one binary with many --options and to create scenarios, that are
hard to put in bash script that uses one binary.

Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx>
---
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/net/tcp_ao/.gitignore | 2 +
tools/testing/selftests/net/tcp_ao/Makefile | 45 +++
tools/testing/selftests/net/tcp_ao/connect.c | 81 +++++
.../testing/selftests/net/tcp_ao/lib/aolib.h | 333 +++++++++++++++++
.../selftests/net/tcp_ao/lib/netlink.c | 341 ++++++++++++++++++
tools/testing/selftests/net/tcp_ao/lib/proc.c | 267 ++++++++++++++
.../testing/selftests/net/tcp_ao/lib/setup.c | 297 +++++++++++++++
tools/testing/selftests/net/tcp_ao/lib/sock.c | 294 +++++++++++++++
.../testing/selftests/net/tcp_ao/lib/utils.c | 30 ++
10 files changed, 1691 insertions(+)
create mode 100644 tools/testing/selftests/net/tcp_ao/.gitignore
create mode 100644 tools/testing/selftests/net/tcp_ao/Makefile
create mode 100644 tools/testing/selftests/net/tcp_ao/connect.c
create mode 100644 tools/testing/selftests/net/tcp_ao/lib/aolib.h
create mode 100644 tools/testing/selftests/net/tcp_ao/lib/netlink.c
create mode 100644 tools/testing/selftests/net/tcp_ao/lib/proc.c
create mode 100644 tools/testing/selftests/net/tcp_ao/lib/setup.c
create mode 100644 tools/testing/selftests/net/tcp_ao/lib/sock.c
create mode 100644 tools/testing/selftests/net/tcp_ao/lib/utils.c

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 10b34bb03bc1..2a3b15a13ccb 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -46,6 +46,7 @@ TARGETS += net
TARGETS += net/af_unix
TARGETS += net/forwarding
TARGETS += net/mptcp
+TARGETS += net/tcp_ao

Please look into a wayto invoke all of them instead of adding individual
net/* to the main Makefile. This list seems to be growing. :)

TARGETS += netfilter
TARGETS += nsfs
TARGETS += pidfd

[snip]

+
+__attribute__((__format__(__printf__, 2, 3)))
+static inline void __test_print(void (*fn)(const char *), const char *fmt, ...)
+{
+#define TEST_MSG_BUFFER_SIZE 4096
+ char buf[TEST_MSG_BUFFER_SIZE];
+ va_list arg;
+
+ va_start(arg, fmt);
+ vsnprintf(buf, sizeof(buf), fmt, arg);
+ va_end(arg);
+ fn(buf);
+}
+

Is there a reason add these instead of using kselftest_* print
functions?

+#define test_print(fmt, ...) \
+ __test_print(__test_msg, "%ld[%s:%u] " fmt "\n", \
+ syscall(SYS_gettid), \
+ __FILE__, __LINE__, ##__VA_ARGS__)
+
+#define test_ok(fmt, ...) \
+ __test_print(__test_ok, fmt "\n", ##__VA_ARGS__)
+
+#define test_fail(fmt, ...) \
+do { \
+ if (errno) \
+ __test_print(__test_fail, fmt ": %m\n", ##__VA_ARGS__); \
+ else \
+ __test_print(__test_fail, fmt "\n", ##__VA_ARGS__); \
+ test_failed(); \
+} while(0)
+
+#define KSFT_FAIL 1
+#define test_error(fmt, ...) \
+do { \
+ if (errno) \
+ __test_print(__test_error, "%ld[%s:%u] " fmt ": %m\n", \
+ syscall(SYS_gettid), __FILE__, __LINE__, \
+ ##__VA_ARGS__); \
+ else \
+ __test_print(__test_error, "%ld[%s:%u] " fmt "\n", \
+ syscall(SYS_gettid), __FILE__, __LINE__, \
+ ##__VA_ARGS__); \
+ exit(KSFT_FAIL); \
+} while(0)
+

Is there a reason add these instead of using kselftest_* print
functions?

+ * Timeout on syscalls where failure is not expected.
+ * You may want to rise it if the test machine is very busy.
+ */
+#ifndef TEST_TIMEOUT_SEC
+#define TEST_TIMEOUT_SEC 5
+#endif
+

Where is the TEST_TIMEOUT_SEC usually defined? Does this come
from shell wrapper that runs this test? Can we add a message before
starting the test print the timeout used?

+/*
+ * Timeout on connect() where a failure is expected.
+ * If set to 0 - kernel will try to retransmit SYN number of times, set in
+ * /proc/sys/net/ipv4/tcp_syn_retries
+ * By default set to 1 to make tests pass faster on non-busy machine.
+ */
+#ifndef TEST_RETRANSMIT_SEC
+#define TEST_RETRANSMIT_SEC 1
+#endif
+

Where would this TEST_RETRANSMIT_SEC defined usually?

+
+static inline int _test_connect_socket(int sk, const union tcp_addr taddr,
+ unsigned port, time_t timeout)
+{
+#ifdef IPV6_TEST
+ struct sockaddr_in6 addr = {
+ .sin6_family = AF_INET6,
+ .sin6_port = htons(port),
+ .sin6_addr = taddr.a6,
+ };
+#else
+ struct sockaddr_in addr = {
+ .sin_family = AF_INET,
+ .sin_port = htons(port),
+ .sin_addr = taddr.a4,
+ };
+#endif

Why do we defined these here - are they also defined in a kernel
header?

+ return __test_connect_socket(sk, (void *)&addr, sizeof(addr), timeout);
+}
+
+static inline int test_connect_socket(int sk,
+ const union tcp_addr taddr, unsigned port)
+{
+ return _test_connect_socket(sk, taddr, port, TEST_TIMEOUT_SEC);
+}
+
+extern int test_prepare_ao_sockaddr(struct tcp_ao *ao,
+ const char *alg, uint16_t flags,
+ void *addr, size_t addr_sz, uint8_t prefix,
+ uint8_t sndid, uint8_t rcvid, uint8_t maclen,
+ uint8_t keyflags, uint8_t keylen, const char *key);
+
+static inline int test_prepare_ao(struct tcp_ao *ao,
+ const char *alg, uint16_t flags,
+ union tcp_addr in_addr, uint8_t prefix,
+ uint8_t sndid, uint8_t rcvid, uint8_t maclen,
+ uint8_t keyflags, uint8_t keylen, const char *key)
+{
+#ifdef IPV6_TEST
+ struct sockaddr_in6 addr = {
+ .sin6_family = AF_INET6,
+ .sin6_port = 0,
+ .sin6_addr = in_addr.a6,
+ };
+#else
+ struct sockaddr_in addr = {
+ .sin_family = AF_INET,
+ .sin_port = 0,
+ .sin_addr = in_addr.a4,
+ };
+#endif
+

Same question here. In general having these ifdefs isn't ideal without
a good reason.

+ return test_prepare_ao_sockaddr(ao, alg, flags,
+ (void *)&addr, sizeof(addr), prefix, sndid, rcvid,
+ maclen, keyflags, keylen, key);
+}
+
+static inline int test_prepare_def_ao(struct tcp_ao *ao,
+ const char *key, uint16_t flags,
+ union tcp_addr in_addr, uint8_t prefix,
+ uint8_t sndid, uint8_t rcvid)
+{
+ if (prefix > DEFAULT_TEST_PREFIX)
+ prefix = DEFAULT_TEST_PREFIX;
+
+ return test_prepare_ao(ao, DEFAULT_TEST_ALGO, flags, in_addr,
+ prefix, sndid, rcvid, 0, 0, strlen(key), key);
+}
+
+extern int test_get_one_ao(int sk, struct tcp_ao_getsockopt *out,
+ uint16_t flags, void *addr, size_t addr_sz,
+ uint8_t prefix, uint8_t sndid, uint8_t rcvid);
+extern int test_cmp_getsockopt_setsockopt(const struct tcp_ao *a,
+ const struct tcp_ao_getsockopt *b);
+
+static inline int test_verify_socket_ao(int sk, struct tcp_ao *ao)
+{
+ struct tcp_ao_getsockopt tmp;
+ int err;
+
+ err = test_get_one_ao(sk, &tmp, 0, &ao->tcpa_addr,
+ sizeof(ao->tcpa_addr), ao->tcpa_prefix,
+ ao->tcpa_sndid, ao->tcpa_rcvid);
+ if (err)
+ return err;

Is this always an error or could this a skip if dependencies aren't
met to run the test? This is a global comment for all error cases.

+
+ return test_cmp_getsockopt_setsockopt(ao, &tmp);
+}
+
+static inline int test_set_ao(int sk, const char *key, uint16_t flags,
+ union tcp_addr in_addr, uint8_t prefix,
+ uint8_t sndid, uint8_t rcvid)
+{
+ struct tcp_ao tmp;
+ int err;
+
+ err = test_prepare_def_ao(&tmp, key, flags, in_addr,
+ prefix, sndid, rcvid);
+ if (err)
+ return err;

Same comment as above here.

+
+ if (setsockopt(sk, IPPROTO_TCP, TCP_AO, &tmp, sizeof(tmp)) < 0)
+ return -errno;
+
+ return test_verify_socket_ao(sk, &tmp);
+}
+
+extern ssize_t test_server_run(int sk, ssize_t quota, time_t timeout_sec);
+extern ssize_t test_client_loop(int sk, char *buf, size_t buf_sz,
+ const size_t msg_len, time_t timeout_sec);
+extern int test_client_verify(int sk, const size_t msg_len, const size_t nr,
+ time_t timeout_sec);
+
+struct netstat;
+extern struct netstat *netstat_read(void);
+extern void netstat_free(struct netstat *ns);
+extern void netstat_print_diff(struct netstat *nsa, struct netstat *nsb);
+extern uint64_t netstat_get(struct netstat *ns,
+ const char *name, bool *not_found);
+
+static inline uint64_t netstat_get_one(const char *name, bool *not_found)
+{
+ struct netstat *ns = netstat_read();
+ uint64_t ret;
+
+ ret = netstat_get(ns, name, not_found);
+
+ netstat_free(ns);
+ return ret;
+}
+
+#endif /* _AOLIB_H_ */
diff --git a/tools/testing/selftests/net/tcp_ao/lib/netlink.c b/tools/testing/selftests/net/tcp_ao/lib/netlink.c
new file mode 100644
index 000000000000..f04757c921d0
--- /dev/null
+++ b/tools/testing/selftests/net/tcp_ao/lib/netlink.c
@@ -0,0 +1,341 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Original from tools/testing/selftests/net/ipsec.c */
+#include <linux/netlink.h>
+#include <linux/random.h>
+#include <linux/rtnetlink.h>
+#include <linux/veth.h>
+#include <net/if.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/socket.h>
+
+#include "aolib.h"
+
+#define MAX_PAYLOAD 2048

tools/testing/selftests/net/gro.c seem to define this as:

#define MAX_PAYLOAD (IP_MAXPACKET - sizeof(struct tcphdr) - sizeof(struct ipv6hdr))

Can you do the same instead of hard-coding?


+
+const struct sockaddr_in6 addr_any6 = {
+ .sin6_family = AF_INET6,
+};
+
+const struct sockaddr_in addr_any4 = {
+ .sin_family = AF_INET,
+};


A couple of things to look at closely. For some failures such as
memory allocation for the test or not being able to open a file

fnetstat = fopen("/proc/net/netstat", "r");

Is this a failure or missing config or not having the right permissions
to open the fail. All of these cases would be a SKIP and not a test fail.

thanks,
-- Shuah