non-regular.c

// SPDX-License-Identifier: GPL-2.0+
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include <sys/types.h>

#include "../kselftest_harness.h"

/* Remove a file, ignoring the result if it didn't exist. */
void rm(struct __test_metadata *_metadata, const char *pathname,
	int is_dir)
{
	int rc;

	if (is_dir)
		rc = rmdir(pathname);
	else
		rc = unlink(pathname);

	if (rc < 0) {
		ASSERT_EQ(errno, ENOENT) {
			TH_LOG("Not ENOENT: %s", pathname);
		}
	} else {
		ASSERT_EQ(rc, 0) {
			TH_LOG("Failed to remove: %s", pathname);
		}
	}
}

FIXTURE(file) {
	char *pathname;
	int is_dir;
};

FIXTURE_VARIANT(file)
{
	const char *name;
	int expected;
	int is_dir;
	void (*setup)(struct __test_metadata *_metadata,
		      FIXTURE_DATA(file) *self,
		      const FIXTURE_VARIANT(file) *variant);
	int major, minor, mode; /* for mknod() */
};

void setup_link(struct __test_metadata *_metadata,
		FIXTURE_DATA(file) *self,
		const FIXTURE_VARIANT(file) *variant)
{
	const char * const paths[] = {
		"/bin/true",
		"/usr/bin/true",
	};
	int i;

	for (i = 0; i < ARRAY_SIZE(paths); i++) {
		if (access(paths[i], X_OK) == 0) {
			ASSERT_EQ(symlink(paths[i], self->pathname), 0);
			return;
		}
	}
	ASSERT_EQ(1, 0) {
		TH_LOG("Could not find viable 'true' binary");
	}
}

FIXTURE_VARIANT_ADD(file, S_IFLNK)
{
	.name = "S_IFLNK",
	.expected = ELOOP,
	.setup = setup_link,
};

void setup_dir(struct __test_metadata *_metadata,
	       FIXTURE_DATA(file) *self,
	       const FIXTURE_VARIANT(file) *variant)
{
	ASSERT_EQ(mkdir(self->pathname, 0755), 0);
}

FIXTURE_VARIANT_ADD(file, S_IFDIR)
{
	.name = "S_IFDIR",
	.is_dir = 1,
	.expected = EACCES,
	.setup = setup_dir,
};

void setup_node(struct __test_metadata *_metadata,
		FIXTURE_DATA(file) *self,
		const FIXTURE_VARIANT(file) *variant)
{
	dev_t dev;
	int rc;

	dev = makedev(variant->major, variant->minor);
	rc = mknod(self->pathname, 0755 | variant->mode, dev);
	ASSERT_EQ(rc, 0) {
		if (errno == EPERM)
			SKIP(return, "Please run as root; cannot mknod(%s)",
				variant->name);
	}
}

FIXTURE_VARIANT_ADD(file, S_IFBLK)
{
	.name = "S_IFBLK",
	.expected = EACCES,
	.setup = setup_node,
	/* /dev/loop0 */
	.major = 7,
	.minor = 0,
	.mode = S_IFBLK,
};

FIXTURE_VARIANT_ADD(file, S_IFCHR)
{
	.name = "S_IFCHR",
	.expected = EACCES,
	.setup = setup_node,
	/* /dev/zero */
	.major = 1,
	.minor = 5,
	.mode = S_IFCHR,
};

void setup_fifo(struct __test_metadata *_metadata,
		FIXTURE_DATA(file) *self,
		const FIXTURE_VARIANT(file) *variant)
{
	ASSERT_EQ(mkfifo(self->pathname, 0755), 0);
}

FIXTURE_VARIANT_ADD(file, S_IFIFO)
{
	.name = "S_IFIFO",
	.expected = EACCES,
	.setup = setup_fifo,
};

FIXTURE_SETUP(file)
{
	ASSERT_GT(asprintf(&self->pathname, "%s.test", variant->name), 6);
	self->is_dir = variant->is_dir;

	rm(_metadata, self->pathname, variant->is_dir);
	variant->setup(_metadata, self, variant);
}

FIXTURE_TEARDOWN(file)
{
	rm(_metadata, self->pathname, self->is_dir);
}

TEST_F(file, exec_errno)
{
	char * const argv[2] = { (char * const)self->pathname, NULL };

	EXPECT_LT(execv(argv[0], argv), 0);
	EXPECT_EQ(errno, variant->expected);
}

/* S_IFSOCK */
FIXTURE(sock)
{
	int fd;
};

FIXTURE_SETUP(sock)
{
	self->fd = socket(AF_INET, SOCK_STREAM, 0);
	ASSERT_GE(self->fd, 0);
}

FIXTURE_TEARDOWN(sock)
{
	if (self->fd >= 0)
		ASSERT_EQ(close(self->fd), 0);
}

TEST_F(sock, exec_errno)
{
	char * const argv[2] = { " magic socket ", NULL };
	char * const envp[1] = { NULL };

	EXPECT_LT(fexecve(self->fd, argv, envp), 0);
	EXPECT_EQ(errno, EACCES);
}

TEST_HARNESS_MAIN