[PATCH 1/3] lib: Add tst_fd_iterate()

[Cyril Hrubis <chrubis@suse.cz>]

Which allows us to call a function on bunch of different file
descriptors.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
---
 include/tst_fd.h   |  39 +++++++++++++++
 include/tst_test.h |   1 +
 lib/tst_fd.c       | 116 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 156 insertions(+)
 create mode 100644 include/tst_fd.h
 create mode 100644 lib/tst_fd.c

diff --git a/include/tst_fd.h b/include/tst_fd.h
new file mode 100644
index 000000000..711e043dd
--- /dev/null
+++ b/include/tst_fd.h
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+/*
+ * Copyright (C) 2023 Cyril Hrubis <chrubis@suse.cz>
+ */
+
+#ifndef TST_FD_H__
+#define TST_FD_H__
+
+enum tst_fd_type {
+	TST_FD_FILE,
+	TST_FD_DIR,
+	TST_FD_DEV_ZERO,
+	TST_FD_PROC_MAPS,
+	TST_FD_PIPE_IN,
+	TST_FD_PIPE_OUT,
+	TST_FD_UNIX_SOCK,
+	TST_FD_INET_SOCK,
+	TST_FD_IO_URING,
+	TST_FD_BPF_MAP,
+	TST_FD_MAX,
+};
+
+struct tst_fd {
+	enum tst_fd_type type;
+	int fd;
+};
+
+/*
+ * Iterates over all fd types and calls the run_test function for each of them.
+ */
+void tst_fd_iterate(void (*run_test)(struct tst_fd *fd));
+
+/*
+ * Returns human readable name for the file descriptor type.
+ */
+const char *tst_fd_desc(struct tst_fd *fd);
+
+#endif /* TST_FD_H__ */
diff --git a/include/tst_test.h b/include/tst_test.h
index 75c2109b9..5eee36bac 100644
--- a/include/tst_test.h
+++ b/include/tst_test.h
@@ -44,6 +44,7 @@
 #include "tst_taint.h"
 #include "tst_memutils.h"
 #include "tst_arch.h"
+#include "tst_fd.h"
 
 /*
  * Reports testcase result.
diff --git a/lib/tst_fd.c b/lib/tst_fd.c
new file mode 100644
index 000000000..7b6cb767e
--- /dev/null
+++ b/lib/tst_fd.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+/*
+ * Copyright (C) 2023 Cyril Hrubis <chrubis@suse.cz>
+ */
+
+#define TST_NO_DEFAULT_MAIN
+
+#include "tst_test.h"
+#include "tst_safe_macros.h"
+#include "lapi/io_uring.h"
+#include "lapi/bpf.h"
+
+#include "tst_fd.h"
+
+const char *tst_fd_desc(struct tst_fd *fd)
+{
+	switch (fd->type) {
+	case TST_FD_FILE:
+		return "regular file";
+	case TST_FD_DIR:
+		return "directory";
+	case TST_FD_DEV_ZERO:
+		return "/dev/zero";
+	case TST_FD_PROC_MAPS:
+		return "/proc/self/maps";
+	case TST_FD_PIPE_IN:
+		return "pipe read end";
+	case TST_FD_PIPE_OUT:
+		return "pipe write end";
+	case TST_FD_UNIX_SOCK:
+		return "unix socket";
+	case TST_FD_INET_SOCK:
+		return "inet socket";
+	case TST_FD_IO_URING:
+		return "io_uring";
+	case TST_FD_BPF_MAP:
+		return "bpf map";
+	case TST_FD_MAX:
+	break;
+	}
+
+	return "invalid";
+}
+
+void tst_fd_iterate(void (*run_test)(struct tst_fd *fd))
+{
+	enum tst_fd_type i;
+	struct tst_fd fd;
+	int pipe[2];
+	struct io_uring_params uring_params = {};
+	union bpf_attr array_attr = {
+		.map_type = BPF_MAP_TYPE_ARRAY,
+		.key_size = 4,
+		.value_size = 8,
+		.max_entries = 1,
+	};
+
+	SAFE_PIPE(pipe);
+
+	for (i = 0; i < TST_FD_MAX; i++) {
+		fd.type = i;
+
+		switch (i) {
+		case TST_FD_FILE:
+			fd.fd = SAFE_OPEN("fd_file", O_RDWR | O_CREAT);
+			SAFE_UNLINK("fd_file");
+		break;
+		case TST_FD_DIR:
+			SAFE_MKDIR("fd_dir", 0700);
+			fd.fd = SAFE_OPEN("fd_dir", O_DIRECTORY);
+			SAFE_RMDIR("fd_dir");
+		break;
+		case TST_FD_DEV_ZERO:
+			fd.fd = SAFE_OPEN("/dev/zero", O_RDONLY);
+		break;
+		case TST_FD_PROC_MAPS:
+			fd.fd = SAFE_OPEN("/proc/self/maps", O_RDONLY);
+		break;
+		case TST_FD_PIPE_IN:
+			fd.fd = pipe[0];
+		break;
+		case TST_FD_PIPE_OUT:
+			fd.fd = pipe[1];
+		break;
+		case TST_FD_UNIX_SOCK:
+			fd.fd = SAFE_SOCKET(AF_UNIX, SOCK_STREAM, 0);
+		break;
+		case TST_FD_INET_SOCK:
+			fd.fd = SAFE_SOCKET(AF_INET, SOCK_STREAM, 0);
+		break;
+		case TST_FD_IO_URING:
+			fd.fd = io_uring_setup(1, &uring_params);
+			if (fd.fd < 0) {
+				tst_res(TCONF | TERRNO,
+					"Skipping %s", tst_fd_desc(&fd));
+				continue;
+			}
+		break;
+		case TST_FD_BPF_MAP:
+			fd.fd = bpf(BPF_MAP_CREATE, &array_attr, sizeof(array_attr));
+			if (fd.fd < 0) {
+				tst_res(TCONF | TERRNO,
+					"Skipping %s", tst_fd_desc(&fd));
+				continue;
+			}
+		break;
+		case TST_FD_MAX:
+		break;
+		}
+
+		run_test(&fd);
+
+		SAFE_CLOSE(fd.fd);
+	}
+}
-- 
2.41.0