[PATCH v5 4/4] DO NOT MERGE: Tests for new eventfd_link module

[Pavel Boldin <pboldin@mirantis.com>]

To use:
1. Compile and load the new eventfd_link module (as root):
 # (cd lib/librte_vhost/eventfd_link; make; insmod ./eventfd_link.ko)
2. Compile the test program:
 $ make -C test_eventfd_copy
3. Run it as root:
 # sudo ./test_eventfd_copy/test_eventfd_copy --check
 Stealing FD OK
---
 test_eventfd_copy/Makefile            |   8 ++
 test_eventfd_copy/rte_log.h           |   2 +
 test_eventfd_copy/test_eventfd_copy.c | 248 ++++++++++++++++++++++++++++++++++
 test_eventfd_copy/vhost-net.h         |   0
 4 files changed, 258 insertions(+)
 create mode 100644 test_eventfd_copy/Makefile
 create mode 100644 test_eventfd_copy/rte_log.h
 create mode 100644 test_eventfd_copy/test_eventfd_copy.c
 create mode 100644 test_eventfd_copy/vhost-net.h

diff --git a/test_eventfd_copy/Makefile b/test_eventfd_copy/Makefile
new file mode 100644
index 0000000..99b3ae3
--- /dev/null
+++ b/test_eventfd_copy/Makefile
@@ -0,0 +1,8 @@
+
+
+test_eventfd_copy: test_eventfd_copy.c \
+                   ../lib/librte_vhost/vhost_cuse/eventfd_copy.c
+	gcc -o $@ $^ \
+	    -I . \
+	    -I ../lib/librte_vhost/ \
+            -I ../lib/librte_vhost/vhost_cuse/
diff --git a/test_eventfd_copy/rte_log.h b/test_eventfd_copy/rte_log.h
new file mode 100644
index 0000000..ffc64c9
--- /dev/null
+++ b/test_eventfd_copy/rte_log.h
@@ -0,0 +1,2 @@
+
+#define RTE_LOG(...)
diff --git a/test_eventfd_copy/test_eventfd_copy.c b/test_eventfd_copy/test_eventfd_copy.c
new file mode 100644
index 0000000..9dfa414
--- /dev/null
+++ b/test_eventfd_copy/test_eventfd_copy.c
@@ -0,0 +1,248 @@
+/*-
+ *   BSD LICENSE
+ *   Copyright(c) 2015 Mirantis Inc. All rights reserved.
+ *   Based on `eventfd_copy.c` from the Intel's DPDK
+
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <unistd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/eventfd.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "eventfd_copy.h"
+
+static void
+usage()
+{
+	fprintf(stderr,
+"test_eventfd_copy (--file-nr [number] | --check)\n"
+"\t--file-nr\tchecks that there is no `struct file' leakage by ensuring that\n"
+"\t\t\t `/proc/sys/fs/file-nr' value is not growing while `eventfd_copy'ing\n"
+"\t\t\t number times (default is 100000)\n"
+"\t--check\t\tchecks that the `fd' is moved correctly\n");
+}
+
+static int
+read_proc_file_nr()
+{
+	int fd, ret;
+	char buf[1024];
+	fd = open("/proc/sys/fs/file-nr", O_RDONLY);
+	if (fd < 0) {
+		perror("open file-nr");
+		return -1;
+	}
+
+	if (read(fd, buf, 1024) < 0) {
+		perror("read");
+		close(fd);
+		return -1;
+	}
+
+	ret = atoi(buf);
+
+	close(fd);
+
+	return ret;
+}
+
+static int
+check_file_nr(int count)
+{
+        pid_t pid;
+	int i, fd;
+
+	pid = getpid();
+
+	fprintf(stderr, "dummy eventfd_copy check for %d file(s)\n", count);
+	fprintf(stdout, "file-nr before: %d\n", read_proc_file_nr());
+        for (i = 0; i < count; ++i) {
+                fd = eventfd_copy(2, pid);
+                if (fd < 0)
+			return 1;
+                close(fd);
+        }
+	fprintf(stdout, "file-nr after: %d\n", read_proc_file_nr());
+
+	return 0;
+}
+
+
+#define FD_TO_LINK 42
+#define SALT	"The Life, the Universe and everything"
+
+/* checks link:
+   0. opens a pipe
+   1. forks
+   2. child opens tempfile
+   3. child dups tempfile fd to fd=42
+   4. child writes salt to the tempfile
+   5. child notifies parent by writing to a pipe
+   6. parent steals child fd
+   7. parent kills child
+   8. parent checks file content
+   9. parent removes tempfile
+ */
+static int
+check_link(void)
+{
+	pid_t cpid;
+	int pipefd[2];
+	char buf;
+
+	if (pipe(pipefd) < 0) {
+		perror("pipe");
+		return 1;
+	}
+
+	cpid = fork();
+	if (cpid == -1) {
+		perror("fork");
+		return 1;
+	}
+
+	if (cpid) {
+		int stolen_fd, ret = 1;
+		char buf[1024], tmpfname[1024] = "";
+
+		close(pipefd[1]);
+
+		if ((ret = read(pipefd[0], tmpfname, 1024)) < 0) {
+			perror("read pipefd");
+			goto parent_out;
+		}
+		close(pipefd[0]);
+
+		stolen_fd = eventfd_copy(FD_TO_LINK, cpid);
+		if (stolen_fd < 0) {
+			goto parent_out;
+		}
+
+		if (lseek(stolen_fd, 0, SEEK_SET) < 0) {
+			perror("lseek");
+			goto parent_out;
+		}
+
+		if (read(stolen_fd, buf, 1024) < 0) {
+			perror("read stolen salt");
+			goto parent_out;
+		}
+
+		if (strcmp(buf, SALT)) {
+			fprintf(stdout, "Stealing FD failed\n");
+		}
+		else {
+			fprintf(stdout, "Stealing FD OK\n");
+		}
+
+		close(stolen_fd);
+
+		ret = 0;
+parent_out:
+		if (tmpfname[0])
+			unlink(tmpfname);
+		kill(cpid, SIGKILL);
+		wait(NULL);
+		return ret;
+	}
+
+	if (cpid == 0) {
+		int fd;
+		char fname[] = "/tmp/linkXXXXXX";
+
+		close(pipefd[0]);
+
+		fd = mkstemp(fname);
+		if (fd < 0) {
+			perror("mkstemp");
+			return 1;
+		}
+
+		if (dup2(fd, FD_TO_LINK) < 0) {
+			perror("dup2");
+			close(fd);
+			return 1;
+		}
+
+		close(fd);
+
+		if (write(FD_TO_LINK, (void*)SALT, strlen(SALT)) < 0) {
+			perror("write salt");
+			return 1;
+		}
+
+		fsync(FD_TO_LINK);
+
+		if (write(pipefd[1], fname, strlen(fname)) < 0) {
+			perror("write pipe");
+			return 1;
+		}
+
+		close(pipefd[1]);
+
+		while (1) {
+			sleep(1);
+		}
+
+		return 0;
+	}
+}
+
+int
+main(int argc, const char** argv)
+{
+	if (argc < 2) {
+		usage();
+		return 0;
+	}
+
+	if (!strcmp(argv[1], "--file-nr")) {
+		int count = 100000;
+		if (argc >= 3)
+			count = atoi(argv[2]);
+		return check_file_nr(count);
+	}
+
+	if (!strcmp(argv[1], "--check")) {
+		return check_link();
+	}
+
+err:
+	usage();
+	return 1;
+}
diff --git a/test_eventfd_copy/vhost-net.h b/test_eventfd_copy/vhost-net.h
new file mode 100644
index 0000000..e69de29
-- 
1.9.1