test: Add test for self dump

It's derived from test.c, but is more self-contained
and explicitly checks for both C and R results.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/libcriu/Makefile

-all: build/test test_sub
+all: build/test test_sub test_self
 .PHONY: all
 
 run: all
@@ -10,6 +10,12 @@ test_sub: test_sub.o
 test_sub.o: test_sub.c
 	gcc -c $^ -I ../../lib -o $@
 
+test_self: test_self.o
+	gcc $^ -L ../../lib -lcriu -o $@
+
+test_self.o: test_self.c
+	gcc -c $^ -I ../../lib -o $@
+
 build/test: build/test.o
 	gcc $^ -L ../../lib -lcriu -o $@
 
@@ -17,5 +23,5 @@ build/test.o: test.c
 	gcc -c $^ -I ../../lib -o $@
 
 clean:
-	rm -rf build test_sub test_sub.o
+	rm -rf build test_sub test_sub.o test_self test_sub.o
 .PHONY: clean

test/libcriu/test_self.c

+#include "criu.h"
+#include <unistd.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <errno.h>
+#include <signal.h>
+#include <sys/wait.h>
+
+static void what_err_ret_mean(ret)
+{
+	/* NOTE: errno is set by libcriu */
+	switch (ret) {
+	case -EBADE:
+		perror("RPC has returned fail");
+		break;
+	case -ECONNREFUSED:
+		perror("Unable to connect to CRIU");
+		break;
+	case -ECOMM:
+		perror("Unable to send/recv msg to/from CRIU");
+		break;
+	case -EINVAL:
+		perror("CRIU doesn't support this type of request."
+		       "You should probably update CRIU");
+		break;
+	case -EBADMSG:
+		perror("Unexpected response from CRIU."
+		       "You should probably update CRIU");
+		break;
+	default:
+		perror("Unknown error type code."
+		       "You should probably update CRIU");
+	}
+}
+
+static inline int chk_exit(int status, int want)
+{
+	if (WIFEXITED(status)) {
+		if (WEXITSTATUS(status) == want) {
+			printf("   `- Success\n");
+			return 0;
+		}
+
+		printf("   `- FAIL (exit %d)\n", WEXITSTATUS(status));
+	} else if (WIFSIGNALED(status))
+		printf("   `- FAIL (die %d)\n", WTERMSIG(status));
+	else
+		printf("   `- FAIL (%#x)\n", status);
+
+	return 1;
+}
+
+#define SUCC_DUMP_ECODE	41
+#define SUCC_RSTR_ECODE	43
+
+int main(int argc, char *argv[])
+{
+	int ret, fd, pid;
+
+	fd = open(argv[2], O_DIRECTORY);
+	if (fd < 0) {
+		perror("Can't open images dir");
+		return 1;
+	}
+
+	criu_init_opts();
+	criu_set_service_address(argv[1]);
+	criu_set_images_dir_fd(fd);
+	criu_set_log_level(4);
+
+	printf("--- Start child ---\n");
+	pid = fork();
+	if (pid < 0) {
+		perror("Can't");
+		return 1;
+	}
+
+	if (!pid) {
+		/*
+		 * Child process -- dump itself, then
+		 * parent would restore us.
+		 */
+
+		close(0);
+		close(1);
+		close(2);
+		if (setsid() < 0)
+			exit(1);
+
+		criu_set_log_file("dump.log");
+		criu_set_leave_running(true);
+		ret = criu_dump();
+		if (ret < 0) {
+			what_err_ret_mean(ret);
+			exit(1);
+		}
+
+		if (ret == 0)
+			ret = SUCC_DUMP_ECODE; /* dumped OK */
+		else if (ret == 1)
+			ret = SUCC_RSTR_ECODE; /* restored OK */
+		else
+			ret = 1;
+
+		exit(ret);
+	}
+
+	printf("--- Wait for self-dump ---\n");
+	if (waitpid(pid, &ret, 0) < 0) {
+		perror("Can't wait child");
+		goto errk;
+	}
+
+	if (chk_exit(ret, SUCC_DUMP_ECODE))
+		goto errk;
+
+	printf("--- Restore ---\n");
+	criu_set_log_file("restore.log");
+
+	pid = criu_restore_child();
+	if (pid <= 0) {
+		what_err_ret_mean(pid);
+		goto err;
+	}
+
+	if (waitpid(pid, &ret, 0) < 0) {
+		perror("Can't wait rchild");
+		goto errk;
+	}
+
+	return chk_exit(ret, SUCC_RSTR_ECODE);
+
+errk:
+	kill(pid, SIGKILL);
+err:
+	return 1;
+
+}