Merge branch 'selftests/bpf: Various sockmap-related fixes'

Michal Luczaj says:

====================
Series takes care of few bugs and missing features with the aim to improve
the test coverage of sockmap/sockhash.

Last patch is a create_pair() rewrite making use of
__attribute__((cleanup)) to handle socket fd lifetime.

---
Changes in v2:
- Rebase on bpf-next (Jakub)
- Use cleanup helpers from kernel's cleanup.h (Jakub)
- Fix subject of patch 3, rephrase patch 4, use correct prefix
- Link to v1: https://lore.kernel.org/r/[email protected]

Changes in v1:
- No declarations in function body (Jakub)
- Don't touch output arguments until function succeeds (Jakub)
- Link to v0: https://lore.kernel.org/netdev/[email protected]/
====================

Signed-off-by: Martin KaFai Lau <[email protected]>

Author: Martin KaFai Lau

tools/testing/selftests/bpf/prog_tests/sockmap_basic.c

@@ -451,11 +451,11 @@ static void test_sockmap_progs_query(enum bpf_attach_type attach_type)
 #define MAX_EVENTS 10
 static void test_sockmap_skb_verdict_shutdown(void)
 {
+	int n, err, map, verdict, c1 = -1, p1 = -1;
 	struct epoll_event ev, events[MAX_EVENTS];
-	int n, err, map, verdict, s, c1 = -1, p1 = -1;
 	struct test_sockmap_pass_prog *skel;
-	int epollfd;
 	int zero = 0;
+	int epollfd;
 	char b;
 
 	skel = test_sockmap_pass_prog__open_and_load();
@@ -469,10 +469,7 @@ static void test_sockmap_skb_verdict_shutdown(void)
 	if (!ASSERT_OK(err, "bpf_prog_attach"))
 		goto out;
 
-	s = socket_loopback(AF_INET, SOCK_STREAM);
-	if (s < 0)
-		goto out;
-	err = create_pair(s, AF_INET, SOCK_STREAM, &c1, &p1);
+	err = create_pair(AF_INET, SOCK_STREAM, &c1, &p1);
 	if (err < 0)
 		goto out;
 
@@ -506,8 +503,8 @@ static void test_sockmap_skb_verdict_shutdown(void)
 
 static void test_sockmap_skb_verdict_fionread(bool pass_prog)
 {
+	int err, map, verdict, c0 = -1, c1 = -1, p0 = -1, p1 = -1;
 	int expected, zero = 0, sent, recvd, avail;
-	int err, map, verdict, s, c0 = -1, c1 = -1, p0 = -1, p1 = -1;
 	struct test_sockmap_pass_prog *pass = NULL;
 	struct test_sockmap_drop_prog *drop = NULL;
 	char buf[256] = "0123456789";
@@ -534,11 +531,8 @@ static void test_sockmap_skb_verdict_fionread(bool pass_prog)
 	if (!ASSERT_OK(err, "bpf_prog_attach"))
 		goto out;
 
-	s = socket_loopback(AF_INET, SOCK_STREAM);
-	if (!ASSERT_GT(s, -1, "socket_loopback(s)"))
-		goto out;
-	err = create_socket_pairs(s, AF_INET, SOCK_STREAM, &c0, &c1, &p0, &p1);
-	if (!ASSERT_OK(err, "create_socket_pairs(s)"))
+	err = create_socket_pairs(AF_INET, SOCK_STREAM, &c0, &c1, &p0, &p1);
+	if (!ASSERT_OK(err, "create_socket_pairs()"))
 		goto out;
 
 	err = bpf_map_update_elem(map, &zero, &c1, BPF_NOEXIST);
@@ -570,16 +564,12 @@ static void test_sockmap_skb_verdict_fionread(bool pass_prog)
 
 static void test_sockmap_skb_verdict_peek_helper(int map)
 {
-	int err, s, c1, p1, zero = 0, sent, recvd, avail;
+	int err, c1, p1, zero = 0, sent, recvd, avail;
 	char snd[256] = "0123456789";
 	char rcv[256] = "0";
 
-	s = socket_loopback(AF_INET, SOCK_STREAM);
-	if (!ASSERT_GT(s, -1, "socket_loopback(s)"))
-		return;
-
-	err = create_pair(s, AF_INET, SOCK_STREAM, &c1, &p1);
-	if (!ASSERT_OK(err, "create_pairs(s)"))
+	err = create_pair(AF_INET, SOCK_STREAM, &c1, &p1);
+	if (!ASSERT_OK(err, "create_pair()"))
 		return;
 
 	err = bpf_map_update_elem(map, &zero, &c1, BPF_NOEXIST);

tools/testing/selftests/bpf/prog_tests/sockmap_helpers.h

@@ -3,6 +3,9 @@
 
 #include <linux/vm_sockets.h>
 
+/* include/linux/net.h */
+#define SOCK_TYPE_MASK 0xf
+
 #define IO_TIMEOUT_SEC 30
 #define MAX_STRERR_LEN 256
 #define MAX_TEST_NAME 80
@@ -14,6 +17,17 @@
 
 #define __always_unused	__attribute__((__unused__))
 
+/* include/linux/cleanup.h */
+#define __get_and_null(p, nullvalue)                                           \
+	({                                                                     \
+		__auto_type __ptr = &(p);                                      \
+		__auto_type __val = *__ptr;                                    \
+		*__ptr = nullvalue;                                            \
+		__val;                                                         \
+	})
+
+#define take_fd(fd) __get_and_null(fd, -EBADF)
+
 #define _FAIL(errnum, fmt...)                                                  \
 	({                                                                     \
 		error_at_line(0, (errnum), __func__, __LINE__, fmt);           \
@@ -179,6 +193,14 @@
 		__ret;                                                         \
 	})
 
+static inline void close_fd(int *fd)
+{
+	if (*fd >= 0)
+		xclose(*fd);
+}
+
+#define __close_fd __attribute__((cleanup(close_fd)))
+
 static inline int poll_connect(int fd, unsigned int timeout_sec)
 {
 	struct timeval timeout = { .tv_sec = timeout_sec };
@@ -312,54 +334,6 @@ static inline int add_to_sockmap(int sock_mapfd, int fd1, int fd2)
 	return xbpf_map_update_elem(sock_mapfd, &key, &value, BPF_NOEXIST);
 }
 
-static inline int create_pair(int s, int family, int sotype, int *c, int *p)
-{
-	struct sockaddr_storage addr;
-	socklen_t len;
-	int err = 0;
-
-	len = sizeof(addr);
-	err = xgetsockname(s, sockaddr(&addr), &len);
-	if (err)
-		return err;
-
-	*c = xsocket(family, sotype, 0);
-	if (*c < 0)
-		return errno;
-	err = xconnect(*c, sockaddr(&addr), len);
-	if (err) {
-		err = errno;
-		goto close_cli0;
-	}
-
-	*p = xaccept_nonblock(s, NULL, NULL);
-	if (*p < 0) {
-		err = errno;
-		goto close_cli0;
-	}
-	return err;
-close_cli0:
-	close(*c);
-	return err;
-}
-
-static inline int create_socket_pairs(int s, int family, int sotype,
-				      int *c0, int *c1, int *p0, int *p1)
-{
-	int err;
-
-	err = create_pair(s, family, sotype, c0, p0);
-	if (err)
-		return err;
-
-	err = create_pair(s, family, sotype, c1, p1);
-	if (err) {
-		close(*c0);
-		close(*p0);
-	}
-	return err;
-}
-
 static inline int enable_reuseport(int s, int progfd)
 {
 	int err, one = 1;
@@ -412,5 +386,84 @@ static inline int socket_loopback(int family, int sotype)
 	return socket_loopback_reuseport(family, sotype, -1);
 }
 
+static inline int create_pair(int family, int sotype, int *p0, int *p1)
+{
+	__close_fd int s, c = -1, p = -1;
+	struct sockaddr_storage addr;
+	socklen_t len = sizeof(addr);
+	int err;
+
+	s = socket_loopback(family, sotype);
+	if (s < 0)
+		return s;
+
+	err = xgetsockname(s, sockaddr(&addr), &len);
+	if (err)
+		return err;
+
+	c = xsocket(family, sotype, 0);
+	if (c < 0)
+		return c;
+
+	err = connect(c, sockaddr(&addr), len);
+	if (err) {
+		if (errno != EINPROGRESS) {
+			FAIL_ERRNO("connect");
+			return err;
+		}
+
+		err = poll_connect(c, IO_TIMEOUT_SEC);
+		if (err) {
+			FAIL_ERRNO("poll_connect");
+			return err;
+		}
+	}
+
+	switch (sotype & SOCK_TYPE_MASK) {
+	case SOCK_DGRAM:
+		err = xgetsockname(c, sockaddr(&addr), &len);
+		if (err)
+			return err;
+
+		err = xconnect(s, sockaddr(&addr), len);
+		if (err)
+			return err;
+
+		*p0 = take_fd(s);
+		break;
+	case SOCK_STREAM:
+	case SOCK_SEQPACKET:
+		p = xaccept_nonblock(s, NULL, NULL);
+		if (p < 0)
+			return p;
+
+		*p0 = take_fd(p);
+		break;
+	default:
+		FAIL("Unsupported socket type %#x", sotype);
+		return -EOPNOTSUPP;
+	}
+
+	*p1 = take_fd(c);
+	return 0;
+}
+
+static inline int create_socket_pairs(int family, int sotype, int *c0, int *c1,
+				      int *p0, int *p1)
+{
+	int err;
+
+	err = create_pair(family, sotype, c0, p0);
+	if (err)
+		return err;
+
+	err = create_pair(family, sotype, c1, p1);
+	if (err) {
+		close(*c0);
+		close(*p0);
+	}
+
+	return err;
+}
 
 #endif // __SOCKMAP_HELPERS__