zdtm: Check full tcp buffers with custom sizes (v2)

* Increase sizes of tcp rcv and snd bufffers
* Fill buffers
* Dump/Restore
* Check, that all data were restored

This test reproduces a problem from buf #2411

v2: don't use test_waitsig() in external processes, because they
   can be out of this pid name-space.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm/live/static/Makefile

@@ -45,6 +45,7 @@ TST_NOFILE	=				\
 		socket_queues			\
 		socket_queues02			\
 		socket-tcp			\
+		socket-tcpbuf			\
 		sock_opts00			\
 		sock_opts01			\
 		ipc_namespace			\

test/zdtm/live/static/socket-tcpbuf.c

+#include "zdtmtst.h"
+
+const char *test_doc = "Check full tcp buffers with custom sizes\n";
+const char *test_author = "Andrey Vagin <avagin@parallels.com";
+
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+
+static int port = 8880;
+
+#define BUF_SIZE 4096
+#define TCP_MAX_BUF (100 << 20)
+
+static int fill_sock_buf(int fd)
+{
+	int flags;
+	int size;
+	int ret;
+
+	flags = fcntl(fd, F_GETFL, 0);
+	if (flags == -1) {
+		err("Can't get flags");
+		return -1;
+	}
+	if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) {
+		err("Can't set flags");
+		return -1;
+	}
+
+	size = 0;
+	while (1) {
+		char zdtm[] = "zdtm test packet";
+		ret = write(fd, zdtm, sizeof(zdtm));
+		if (ret == -1) {
+			if (errno == EAGAIN)
+				break;
+			err("write");
+			return -1;
+		}
+		size += ret;
+	}
+
+	if (fcntl(fd, F_SETFL, flags) == -1) {
+		err("Can't set flags");
+		return -1;
+	}
+
+	test_msg("snd_size = %d\n", size);
+
+	return size;
+}
+
+static int clean_sk_buf(fd)
+{
+	int size, ret;
+	char buf[BUF_SIZE];
+
+	size = 0;
+	while (1) {
+		ret = read(fd, buf, sizeof(buf));
+		if (ret == -1) {
+			err("read");
+			return -11;
+		}
+
+		if (ret == 0)
+			break;
+
+		size += ret;
+	}
+
+	test_msg("rcv_size = %d\n", size);
+
+	return size;
+}
+
+int main(int argc, char **argv)
+{
+	int fd, fd_s, ctl_fd;
+	pid_t extpid;
+	int pfd[2];
+	int sk_bsize;
+	int ret, snd_size, rcv_size;
+
+	if (pipe(pfd)) {
+		err("pipe() failed");
+		return 1;
+	}
+
+	extpid = fork();
+	if (extpid < 0) {
+		err("fork() failed");
+		return 1;
+	} else if (extpid == 0) {
+		int size;
+		char c;
+
+		test_ext_init(argc, argv);
+
+		close(pfd[1]);
+		if (read(pfd[0], &port, sizeof(port)) != sizeof(port)) {
+			err("Can't read port\n");
+			return 1;
+		}
+
+		fd = tcp_init_client("127.0.0.1", port);
+		if (fd < 0)
+			return 1;
+
+		ctl_fd = tcp_init_client("127.0.0.1", port);
+		if (fd < 0)
+			return 1;
+
+		size = fill_sock_buf(fd);
+		if (size <= 0)
+			return 1;
+
+		if (write(ctl_fd, &size, sizeof(size)) != sizeof(size)) {
+			err("write");
+			return 1;
+		}
+
+		if (read(ctl_fd, &c, 1) != 0) {
+			err("read");
+			return 1;
+		}
+
+		if (shutdown(fd, SHUT_WR) == -1) {
+			err("shutdown");
+			return 1;
+		}
+
+		size = clean_sk_buf(fd);
+		if (size < 0)
+			return 1;
+
+		write(ctl_fd, &size, sizeof(size));
+		close(fd);
+
+		return 0;
+	}
+
+	test_init(argc, argv);
+
+	if ((fd_s = tcp_init_server(&port)) < 0) {
+		err("initializing server failed");
+		return 1;
+	}
+
+	close(pfd[0]);
+	if (write(pfd[1], &port, sizeof(port)) != sizeof(port)) {
+		err("Can't send port");
+		return 1;
+	}
+	close(pfd[1]);
+
+	/*
+	 * parent is server of TCP connection
+	 */
+	fd = tcp_accept_server(fd_s);
+	if (fd < 0) {
+		err("can't accept client connection %m");
+		return 1;
+	}
+
+	ctl_fd = tcp_accept_server(fd_s);
+	if (ctl_fd < 0) {
+		err("can't accept client connection %m");
+		return 1;
+	}
+
+	sk_bsize = TCP_MAX_BUF;
+	if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF,
+			&sk_bsize, sizeof(sk_bsize)) == -1) {
+		err("Can't set snd buf");
+		return 1;
+	}
+
+	sk_bsize = TCP_MAX_BUF;
+	if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF,
+			&sk_bsize, sizeof(sk_bsize)) == -1) {
+		err("Can't set snd buf");
+		return 1;
+	}
+
+	snd_size = fill_sock_buf(fd);
+	if (snd_size <= 0)
+		return 1;
+
+	if (read(ctl_fd, &ret, sizeof(ret)) != sizeof(ret)) {
+		err("read");
+		return 1;
+	}
+
+	test_daemon();
+	test_waitsig();
+
+	if (shutdown(ctl_fd, SHUT_WR) == -1) {
+		err("shutdown");
+		return 1;
+	}
+
+	if (shutdown(fd, SHUT_WR) == -1) {
+		err("shutdown");
+		return 1;
+	}
+
+	rcv_size = clean_sk_buf(fd);
+
+	if (ret != rcv_size) {
+		fail("The child sent %d bytes, but the parent recieved %d bytes\n", rcv_size, ret);
+		return 1;
+	}
+
+	if (read(ctl_fd, &ret, sizeof(ret)) != sizeof(ret)) {
+		err("read");
+		return 1;
+	}
+
+	if (ret != snd_size) {
+		fail("The parent sent %d bytes, but the child recieved %d bytes\n", snd_size, ret);
+		return 1;
+	}
+
+	pass();
+	return 0;
+}