1 files changed, 92 insertions, 0 deletions
diff --git a/doc/migration/source.c b/doc/migration/source.c
new file mode 100644
index 0000000..d44ebf1
--- /dev/null
+++ b/doc/migration/source.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+/* PASST - Plug A Simple Socket Transport
+ *  for qemu/UNIX domain socket mode
+ *
+ * PASTA - Pack A Subtle Tap Abstraction
+ *  for network namespace/tap device mode
+ *
+ * doc/migration/source.c - Mock of TCP migration source, use with passt-repair
+ *
+ * Copyright (c) 2025 Red Hat GmbH
+ * Author: Stefano Brivio <sbrivio@redhat.com>
+ */
+
+#include <arpa/inet.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <unistd.h>
+#include <netdb.h>
+#include <netinet/tcp.h>
+
+int main(int argc, char **argv)
+{
+	struct sockaddr_in a = { AF_INET, htons(atoi(argv[3])), { 0 }, { 0 } };
+	struct addrinfo hints = { 0, AF_UNSPEC, SOCK_STREAM, 0, 0,
+				  NULL, NULL, NULL };
+	struct sockaddr_un a_helper = { AF_UNIX, { 0 } };
+	int seq, s, s_helper;
+	int8_t cmd;
+	struct iovec iov = { &cmd, sizeof(cmd) };
+	char buf[CMSG_SPACE(sizeof(int))];
+	struct msghdr msg = { NULL, 0, &iov, 1, buf, sizeof(buf), 0 };
+	struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
+	socklen_t seqlen = sizeof(int);
+	struct addrinfo *r;
+
+	(void)argc;
+
+	if (argc != 5) {
+		fprintf(stderr, "%s DST_ADDR DST_PORT SRC_PORT HELPER_PATH\n",
+			argv[0]);
+		return -1;
+	}
+
+	strcpy(a_helper.sun_path, argv[4]);
+	getaddrinfo(argv[1], argv[2], &hints, &r);
+
+	/* Connect socket to server and send some data */
+	s = socket(r->ai_family, SOCK_STREAM, IPPROTO_TCP);
+	setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &((int){ 1 }), sizeof(int));
+	bind(s, (struct sockaddr *)&a, sizeof(a));
+	connect(s, r->ai_addr, r->ai_addrlen);
+	send(s, "before migration\n", sizeof("before migration\n"), 0);
+
+	/* Wait for helper */
+	s_helper = socket(AF_UNIX, SOCK_STREAM, 0);
+	unlink(a_helper.sun_path);
+	bind(s_helper, (struct sockaddr *)&a_helper, sizeof(a_helper));
+	listen(s_helper, 1);
+	s_helper = accept(s_helper, NULL, NULL);
+
+	/* Set up message for helper, with socket */
+	cmsg->cmsg_level = SOL_SOCKET;
+	cmsg->cmsg_type = SCM_RIGHTS;
+	cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+	memcpy(CMSG_DATA(cmsg), &s, sizeof(s));
+
+	/* Send command to helper: turn repair mode on, wait for reply */
+	cmd = TCP_REPAIR_ON;
+	sendmsg(s_helper, &msg, 0);
+	recv(s_helper, &((int8_t){ 0 }), 1, 0);
+
+	/* Terminate helper */
+	close(s_helper);
+
+	/* Get sending sequence */
+	seq = TCP_SEND_QUEUE;
+	setsockopt(s, SOL_TCP, TCP_REPAIR_QUEUE, &seq, sizeof(seq));
+	getsockopt(s, SOL_TCP, TCP_QUEUE_SEQ, &seq, &seqlen);
+	fprintf(stdout, "%u ", seq);
+
+	/* Get receiving sequence */
+	seq = TCP_RECV_QUEUE;
+	setsockopt(s, SOL_TCP, TCP_REPAIR_QUEUE, &seq, sizeof(seq));
+	getsockopt(s, SOL_TCP, TCP_QUEUE_SEQ, &seq, &seqlen);
+	fprintf(stdout, "%u\n", seq);
+}