Add test for dumping\restoring unnamed unix sockets.

* Added test for dumping\restoring of unnamed unix sockets.
  Also test added to test/Makefile. Use make run for launch.

* Cleanup env after call run.sh in test/libcriu.
Signed-off-by: Artem Kuzmitskiy <artem.kuzmitskiy@lge.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/Makefile

@@ -13,7 +13,7 @@ all:
 
 .PHONY: all
 
-TESTS = unix-callback mem-snap rpc libcriu mounts/ext security pipes crit
+TESTS = unix-callback mem-snap rpc libcriu mounts/ext security pipes crit socketpairs
 
 other: .FORCE
 	for t in $(TESTS); do			\

test/libcriu/run.sh

@@ -43,5 +43,6 @@ run_test test_errno
 
 echo "== Stopping service"
 kill -TERM $(cat wdir/s/pidfile)
+unlink libcriu.so.1
 [ $RESULT -eq 0 ] && echo "Success" || echo "FAIL"
 exit $RESULT

test/socketpairs/Makefile

+CFLAGS += -Wall
+socketpair: socketpair.c
+clean:
+	rm -f socketpair
+run: socketpair
+	./socketpair  &&		\
+	./socketpair -v &&		\
+	./socketpair -m4 &&		\
+	true

test/socketpairs/socketpair.c

+/*
+ * A simple demo/test program using criu's --inherit-fd command line
+ * option to restore a process with an external unix socket.
+ * Extending inherit's logic to unix sockets created by socketpair(..) syscall.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <time.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/wait.h>
+#include <sys/prctl.h>
+#include <sys/socket.h>
+
+typedef void (*sighandler_t)(int);
+typedef unsigned long ulong;
+
+/* colors */
+#define CS_PARENT 		"\033[00;32m"
+#define CS_CHILD 		"\033[00;33m"
+#define CS_DUMP 		"\033[00;34m"
+#define CS_RESTORE 		"\033[00;35m"
+#define CE			"\033[0m"
+
+#define die(fmt, ...) do { \
+	fprintf(stderr, fmt ": %m\n", __VA_ARGS__); \
+	if (getpid() == parent_pid) { \
+		(void)kill(0, 9); \
+		exit(1); \
+	} \
+	_exit(1); \
+} while (0)
+
+#define READ_FD		0	/* pipe read fd */
+#define WRITE_FD	1	/* pipe write fd */
+#define CLASH_FD	3	/* force inherit fd clash */
+
+#define MAX_FORKS	3	/* child, checkpoint, restore */
+
+#define CRIU_BINARY		"../../criu"
+#define IMG_DIR			"images"
+#define DUMP_LOG_FILE		"dump.log"
+#define RESTORE_LOG_FILE	"restore.log"
+#define RESTORE_PID_FILE	"restore.pid"
+#define INHERIT_FD_OPTION	"--inherit-fd"
+#define OLD_LOG_FILE		"/tmp/oldlog"
+#define NEW_LOG_FILE		"/tmp/newlog"
+
+/*
+ * Command line options (see usage()).
+ */
+
+char *cli_flags = "hm:nv";
+int max_msgs = 10;
+int vflag;
+int nflag;
+
+char pid_number[8];
+char inh_unixsk_opt[16];
+char inh_unixsk_arg[64];
+char external_sk_ino[32];
+
+char *dump_argv[] = {
+	"criu", "dump",
+	"-D", IMG_DIR, "-o", DUMP_LOG_FILE,
+	"-v4",
+	external_sk_ino,
+	"-t", pid_number,
+	NULL
+};
+
+char *restore_argv[] = {
+	"criu", "restore", "-d",
+	"-D", IMG_DIR, "-o", RESTORE_LOG_FILE,
+	"--pidfile", RESTORE_PID_FILE,
+	"-v4", "-x",
+	inh_unixsk_opt, inh_unixsk_arg,
+	NULL
+};
+
+int max_forks;
+int parent_pid;
+int child_pid;
+int criu_dump_pid;
+int criu_restore_pid;
+
+/* prototypes */
+void chld_handler(int signum);
+int parent(int *socketfd, const char *ino_child_sk);
+int child(int *socketfd, int dupfd, int newfd);
+void checkpoint_child(int child_pid, int *old_socket_namefd);
+void restore_child(int *new_socketfd, const char *old_socket_name);
+void write_to_fd(int fd, char *name, int i, int newline);
+void ls_proc_fd(int fd);
+char *socket_name(int fd);
+ino_t socket_inode(int fd);
+char *who(pid_t pid);
+void socketpair_safe(int socketfd[2]);
+pid_t fork_safe(void);
+void signal_safe(int signum, sighandler_t handler);
+int open_safe(char *pathname, int flags);
+void close_safe(int fd);
+void write_safe(int fd, char *buf, int count);
+int read_safe(int fd, char *buf, int count);
+int dup_safe(int oldfd);
+void move_fd(int oldfd, int newfd);
+void mkdir_safe(char *dirname, int mode);
+void unlink_safe(char *pathname);
+void execv_safe(char *path, char *argv[], int ls);
+pid_t waitpid_safe(pid_t pid, int *status, int options, int id);
+void prctl_safe(int option, ulong arg2, ulong arg3, ulong arg4, ulong arg5);
+int dup2_safe(int oldfd, int newfd);
+
+void usage(char *cmd)
+{
+	printf("Usage: %s [%s]\n", cmd, cli_flags);
+	printf("-h\tprint this help and exit\n");
+	printf("-m\tcount of send messages (by default 10 will send from child) \n");
+	printf("-n\tdo not use the %s option\n", INHERIT_FD_OPTION);
+	printf("-v\tverbose mode (list contents of /proc/<pid>/fd)\n");
+}
+
+int main(int argc, char *argv[])
+{
+	int ret;
+	int opt;
+	int socketfd[2];
+
+	while ((opt = getopt(argc, argv, cli_flags)) != -1) {
+		switch (opt) {
+		case 'h':
+			usage(argv[0]);
+			return 0;
+		case 'm':
+			max_msgs = atoi(optarg);
+			break;
+		case 'n':
+			nflag++;
+			break;
+		case 'v':
+			vflag++;
+			break;
+		case '?':
+			if ('m' == optopt)
+				fprintf (stderr, "Option -%c requires an argument.\n", optopt);
+			else
+			fprintf (
+				stderr,
+				"Unknown option character `\\x%x'.\n",
+				optopt);
+			return 1;
+		default:
+			usage(argv[0]);
+			return 1;
+		}
+	}
+
+	setbuf(stdout, NULL);
+	setbuf(stderr, NULL);
+	mkdir_safe(IMG_DIR, 0700);
+
+	socketpair_safe(socketfd);
+	child_pid = fork_safe();
+	if (child_pid > 0) {
+		parent_pid = getpid();
+
+		signal_safe(SIGCHLD, chld_handler);
+		prctl_safe(PR_SET_CHILD_SUBREAPER, 1, 0, 0, 0);
+
+		snprintf(external_sk_ino, sizeof(external_sk_ino), "--ext-unix-sk=%u",
+			(unsigned int)socket_inode(socketfd[WRITE_FD]));
+
+		char unix_sk_ino[32] = {0};
+		strcpy(unix_sk_ino, socket_name(socketfd[WRITE_FD]));
+		close_safe(socketfd[WRITE_FD]);
+		ret = parent(socketfd, unix_sk_ino);
+	} else {
+		/* child */
+		int dupfd = -1;
+		int openfd = -1;
+		int logfd;
+
+		child_pid = getpid();
+
+		close_safe(socketfd[READ_FD]);
+		setsid();
+		logfd = open_safe(OLD_LOG_FILE, O_WRONLY | O_APPEND | O_CREAT);
+		dup2_safe(logfd, 1);
+		dup2_safe(logfd, 2);
+		close(logfd);
+		close(0);
+
+		ret = child(socketfd, dupfd, openfd);
+	}
+
+	return ret;
+}
+
+/*
+ * Parent reads message from its pipe with the child.
+ * After a couple of messages, it checkpoints the child
+ * which causes the child to exit.  Parent then creates
+ * a new pipe and restores the child.
+ */
+int parent(int *socketfd, const char *ino_child_sk)
+{
+	char buf[32];
+	int nread;
+
+	nread = 0;
+	while (max_forks <= MAX_FORKS) {
+		if (read_safe(socketfd[READ_FD], buf, sizeof buf) == 0)
+			continue;
+		nread++;
+		if (vflag && nread == 1)
+			ls_proc_fd(-1);
+
+		printf(
+			"%s read %s from %s\n",
+			who(0), buf,
+			socket_name(socketfd[READ_FD]));
+
+
+		if (nread == (max_msgs / 2)) {
+			checkpoint_child(child_pid, socketfd);
+
+			if (!nflag) {
+				close_safe(socketfd[READ_FD]);
+
+				/* create a new one */
+				printf("%s creating a new socket\n", who(0));
+				socketpair_safe(socketfd);
+			}
+
+			restore_child(socketfd, ino_child_sk);
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Child sends a total of max_messages messages to its
+ * parent, half before checkpoint and half after restore.
+ */
+int child(int *socketfd, int dupfd, int openfd)
+{
+	int i;
+	int fd;
+	int num_wfds;
+	struct timespec req = { 1, 0 };
+
+	/*
+	 * Count the number of pipe descriptors we'll be
+	 * writing to.  At least 1 (for socketfd[WRITE_FD])
+	 * and at most 3.
+	 */
+	num_wfds = 1;
+	if (dupfd >= 0)
+		num_wfds++;
+	if (openfd >= 0)
+		num_wfds++;
+
+	for (i = 0; i < max_msgs; i++) {
+		/* print first time and after checkpoint */
+		if (vflag && (i == 0 || i == (max_msgs / 2)))
+			ls_proc_fd(-1);
+
+		switch (i % num_wfds) {
+			case 0: fd = socketfd[WRITE_FD]; break;
+			case 1: fd = openfd; break;
+			case 2: fd = openfd; break;
+		}
+
+		write_to_fd(fd, socket_name(socketfd[WRITE_FD]), i+1, 0);
+		/*
+		 * Since sleep will be interrupted by C/R, make sure
+		 * to sleep an entire second to minimize the chance of
+		 * writing before criu restore has exited.  If criu is
+		 * still around and we write to a broken pipe, we'll be
+		 * killed but SIGCHLD will be delivered to criu instead
+		 * of parent.
+		 */
+		while (nanosleep(&req, NULL))
+			;
+		printf("\n");
+	}
+
+	return 0;
+}
+
+void chld_handler(int signum)
+{
+	int status;
+	pid_t pid;
+
+	pid = waitpid_safe(-1, &status, WNOHANG, 1);
+	if (WIFEXITED(status))
+		status = WEXITSTATUS(status);
+	if (pid == child_pid) {
+		printf("%s %s exited with status %d\n", who(0),
+			who(pid), status);
+		/* if child exited successfully, we're done */
+		if (status == 0)
+			exit(0);
+		/* checkpoint kills the child */
+		if (status != 9)
+			exit(status);
+	}
+}
+
+void checkpoint_child(int child_pid, int *socketfd)
+{
+	/* prepare -t <pid> */
+	snprintf(pid_number, sizeof pid_number, "%d", child_pid);
+
+	criu_dump_pid = fork_safe();
+	if (criu_dump_pid > 0) {
+		int status;
+		pid_t pid;
+
+		pid = waitpid_safe(criu_dump_pid, &status, 0, 2);
+		if (WIFEXITED(status))
+			status = WEXITSTATUS(status);
+		printf("%s %s exited with status %d\n", who(0),
+			who(pid), status);
+		if (status)
+			exit(status);
+	} else {
+		close(socketfd[READ_FD]);
+		criu_dump_pid = getpid();
+		execv_safe(CRIU_BINARY, dump_argv, 0);
+	}
+}
+
+void restore_child(int *new_socketfd, const char *old_sock_name)
+{
+	char buf[64];
+
+	criu_restore_pid = fork_safe();
+	if (criu_restore_pid > 0) {
+		int status;
+		pid_t pid;
+
+		if (!nflag)
+			close_safe(new_socketfd[WRITE_FD]);
+
+		pid = waitpid_safe(criu_restore_pid, &status, 0, 3);
+		if (WIFEXITED(status))
+			status = WEXITSTATUS(status);
+
+		printf("%s %s exited with status %d\n", who(0),
+			who(pid), status);
+
+		if (status)
+			exit(status);
+	} else {
+		criu_restore_pid = getpid();
+
+		if (!nflag) {
+			close_safe(new_socketfd[READ_FD]);
+			move_fd(new_socketfd[WRITE_FD], CLASH_FD);
+
+			/* --inherit-fd fd[CLASH_FD]:socket[xxxxxx] */
+			snprintf(inh_unixsk_opt, sizeof inh_unixsk_opt,
+				"%s", INHERIT_FD_OPTION);
+			snprintf(inh_unixsk_arg, sizeof inh_unixsk_arg, "fd[%d]:%s",
+				CLASH_FD, old_sock_name);
+
+			restore_argv[11] = inh_unixsk_opt;
+			restore_argv[13] = NULL;
+		} else
+			restore_argv[11] = NULL;
+
+		snprintf(buf, sizeof buf, "%s/%s", IMG_DIR, RESTORE_PID_FILE);
+		unlink_safe(buf);
+		execv_safe(CRIU_BINARY, restore_argv, 1);
+	}
+}
+
+void write_to_fd(int fd, char *name, int i, int newline)
+{
+	int n;
+	char buf[16];	/* fit "hello d\n" for small d */
+
+	n = snprintf(buf, sizeof buf, "hello %d", i);
+
+	printf("%s writing %s to %s via fd %d\n", who(0), buf, name, fd);
+
+	if (newline) {
+		buf[n++] = '\n';
+		buf[n] = '\0';
+	}
+	write_safe(fd, buf, strlen(buf));
+}
+
+void ls_proc_fd(int fd)
+{
+	char cmd[128];
+
+	if (fd == -1)
+		snprintf(cmd, sizeof cmd, "ls -l /proc/%d/fd", getpid());
+	else
+		snprintf(cmd, sizeof cmd, "ls -l /proc/%d/fd/%d", getpid(), fd);
+	printf("%s %s\n", who(0), cmd);
+	system(cmd);
+}
+
+char *socket_name(int fd)
+{
+	static char sock_name[64];
+	char path[64];
+
+	snprintf(path, sizeof path, "/proc/self/fd/%d", fd);
+	if (readlink(path, sock_name, sizeof sock_name) == -1)
+		die("readlink: path=%s", path);
+	return sock_name;
+}
+
+ino_t socket_inode(int fd)
+{
+         struct stat sbuf;
+
+         if (fstat(fd, &sbuf) == -1)
+                 die("fstat: fd=%i", fd);
+
+         return sbuf.st_ino;
+}
+
+/*
+ * Use two buffers to support two calls to
+ * this function in a printf argument list.
+ */
+char *who(pid_t pid)
+{
+	static char pidstr1[64];
+	static char pidstr2[64];
+	static char *cp;
+	char *np;
+	char *ep;
+	int p;
+
+	p = pid ? pid : getpid();
+	if (p == parent_pid) {
+		np = "parent";
+		ep = CS_PARENT;
+	} else if (p == child_pid) {
+		np = "child";
+		ep = CS_CHILD;
+	} else if (p == criu_dump_pid) {
+		np = "dump";
+		ep = CS_DUMP;
+	} else if (p == criu_restore_pid) {
+		np = "restore";
+		ep = CS_RESTORE;
+	} else
+		np = "???";
+
+	cp = (cp == pidstr1) ? pidstr2 : pidstr1;
+	snprintf(cp, sizeof pidstr1, "%s[%s %d]", pid ? "" : ep, np, p);
+	return cp;
+}
+
+void socketpair_safe(int socketfd[2])
+{
+	if (socketpair(AF_UNIX, SOCK_STREAM, 0, socketfd) == -1)
+		die("socketpair %p", socketfd);
+}
+
+pid_t fork_safe(void)
+{
+	pid_t pid;
+
+	if ((pid = fork()) == -1)
+		die("fork: pid=%d", pid);
+	max_forks++;
+	return pid;
+}
+
+void signal_safe(int signum, sighandler_t handler)
+{
+	if (signal(signum, handler) == SIG_ERR)
+		die("signal: signum=%d", signum);
+}
+
+int open_safe(char *pathname, int flags)
+{
+	int fd;
+
+	if ((fd = open(pathname, flags, 0777)) == -1)
+		die("open: pathname=%s", pathname);
+	return fd;
+}
+
+void close_safe(int fd)
+{
+	if (close(fd) == -1)
+		die("close: fd=%d", fd);
+}
+
+void write_safe(int fd, char *buf, int count)
+{
+	if (write(fd, buf, count) != count) {
+		die("write: fd=%d buf=\"%s\" count=%d errno=%d",
+			fd, buf, count, errno);
+	}
+}
+
+int read_safe(int fd, char *buf, int count)
+{
+	int n;
+
+	if ((n = read(fd, buf, count)) < 0)
+		die("read: fd=%d count=%d", fd, count);
+	buf[n] = '\0';
+	return n;
+}
+
+int dup_safe(int oldfd)
+{
+	int newfd;
+
+	if ((newfd = dup(oldfd)) == -1)
+		die("dup: oldfd=%d", oldfd);
+	return newfd;
+}
+
+int dup2_safe(int oldfd, int newfd)
+{
+	if (dup2(oldfd, newfd) != newfd)
+		die("dup2: oldfd=%d newfd=%d", oldfd, newfd);
+	return newfd;
+}
+
+void move_fd(int oldfd, int newfd)
+{
+	if (oldfd != newfd) {
+		dup2_safe(oldfd, newfd);
+		close_safe(oldfd);
+	}
+}
+
+void mkdir_safe(char *dirname, int mode)
+{
+	if (mkdir(dirname, mode) == -1 && errno != EEXIST)
+		die("mkdir dirname=%s mode=0x%x\n", dirname, mode);
+}
+
+void unlink_safe(char *pathname)
+{
+	if (unlink(pathname) == -1 && errno != ENOENT) {
+		die("unlink: pathname=%s\n", pathname);
+	}
+}
+
+void execv_safe(char *path, char *argv[], int ls)
+{
+	int i;
+	struct timespec req = { 0, 1000000 };
+
+	printf("\n%s ", who(0));
+	for (i = 0; argv[i] != NULL; i++)
+		printf("%s ", argv[i]);
+	printf("\n");
+
+	/* give parent a chance to wait for us */
+	while (nanosleep(&req, NULL))
+		;
+
+	if (vflag && ls)
+		ls_proc_fd(-1);
+
+	execv(path, argv);
+	die("execv: path=%s", path);
+}
+
+pid_t waitpid_safe(pid_t pid, int *status, int options, int id)
+{
+	pid_t p;
+
+	p = waitpid(pid, status, options);
+	if (p == -1)
+		fprintf(stderr, "waitpid pid=%d id=%d %m\n", pid, id);
+	return p;
+}
+
+void prctl_safe(int option, ulong arg2, ulong arg3, ulong arg4, ulong arg5)
+{
+	if (prctl(option, arg2, arg3, arg4, arg5) == -1)
+		die("prctl: option=0x%x", option);
+}