[PATCH v2 2/2] selftests: Add udp_repair test

[Bui Quang Minh <minhquangbui99@gmail.com>]

This is a simple test for UDP_REPAIR in 3 cases:
 - Socket is an udp4 socket
 - Socket is an udp6 socket with pending ipv4 packets
 - Socket is an udp6 socket with pending ipv6 packets

Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
---
 tools/testing/selftests/net/.gitignore   |   1 +
 tools/testing/selftests/net/Makefile     |   1 +
 tools/testing/selftests/net/udp_repair.c | 218 +++++++++++++++++++++++
 3 files changed, 220 insertions(+)
 create mode 100644 tools/testing/selftests/net/udp_repair.c

diff --git a/tools/testing/selftests/net/.gitignore b/tools/testing/selftests/net/.gitignore
index 19deb9cdf72f..c9daab1721d5 100644
--- a/tools/testing/selftests/net/.gitignore
+++ b/tools/testing/selftests/net/.gitignore
@@ -31,3 +31,4 @@ rxtimestamp
 timestamping
 txtimestamp
 so_netns_cookie
+udp_repair
diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index 4f9f73e7a299..602f798c8880 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -42,6 +42,7 @@ TEST_GEN_FILES += gro
 TEST_GEN_PROGS = reuseport_bpf reuseport_bpf_cpu reuseport_bpf_numa
 TEST_GEN_PROGS += reuseport_dualstack reuseaddr_conflict tls
 TEST_GEN_FILES += toeplitz
+TEST_GEN_PROGS += udp_repair
 
 TEST_FILES := settings
 
diff --git a/tools/testing/selftests/net/udp_repair.c b/tools/testing/selftests/net/udp_repair.c
new file mode 100644
index 000000000000..1b2c53129c71
--- /dev/null
+++ b/tools/testing/selftests/net/udp_repair.c
@@ -0,0 +1,218 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <string.h>
+#include <unistd.h>
+#include <error.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <netinet/udp.h>
+
+#define PORT 5000
+#define BUF_SIZE 256
+
+#define UDP_REPAIR	2
+
+char send_buf[BUF_SIZE];
+struct udp_dump {
+	union {
+		struct sockaddr_in addr_v4;
+		struct sockaddr_in6 addr_v6;
+	};
+	char buf[BUF_SIZE];
+};
+
+struct sockaddr_in addr_v4;
+struct sockaddr_in6 addr_v6;
+
+int udp_server(int is_udp4)
+{
+	int sock, ret;
+	unsigned short family;
+	struct sockaddr *server_addr;
+	unsigned int addr_len;
+
+	if (is_udp4) {
+		family = AF_INET;
+		server_addr = (struct sockaddr *) &addr_v4;
+		addr_len = sizeof(addr_v4);
+	} else {
+		family = AF_INET6;
+		server_addr = (struct sockaddr *) &addr_v6;
+		addr_len = sizeof(addr_v6);
+	}
+
+	sock = socket(family, SOCK_DGRAM, IPPROTO_UDP);
+	if (sock < 0)
+		error(1, errno, "socket server");
+
+	ret = bind(sock, server_addr, addr_len);
+	if (ret < 0)
+		error(1, errno, "bind server socket");
+
+	return sock;
+}
+
+void server_recv(int sock)
+{
+	char recv_buf[BUF_SIZE];
+	int ret;
+
+	ret = recv(sock, recv_buf, sizeof(recv_buf), 0);
+	if (ret < 0)
+		error(1, errno, "recv in server");
+
+	if (memcmp(recv_buf, send_buf, BUF_SIZE))
+		error(1, 0, "recv: data mismatch");
+}
+
+int create_corked_udp_client(int is_udp4)
+{
+	int sock, ret, val = 1;
+	unsigned short family = is_udp4 ? AF_INET : AF_INET6;
+
+	sock = socket(family, SOCK_DGRAM, IPPROTO_UDP);
+	if (sock < 0)
+		error(1, errno, "socket client");
+
+	ret = setsockopt(sock, SOL_UDP, UDP_CORK, &val, sizeof(val));
+	if (ret < 0)
+		error(1, errno, "setsockopt cork udp");
+
+	return sock;
+}
+
+struct udp_dump *checkpoint(int sock, int is_udp4)
+{
+	int ret, val;
+	unsigned int addr_len;
+	struct udp_dump *dump;
+	struct sockaddr *addr;
+
+	dump = malloc(sizeof(*dump));
+	if (!dump)
+		error(1, 0, "malloc");
+
+	if (is_udp4) {
+		addr = (struct sockaddr *) &dump->addr_v4;
+		addr_len = sizeof(dump->addr_v4);
+	} else {
+		addr = (struct sockaddr *) &dump->addr_v6;
+		addr_len = sizeof(dump->addr_v6);
+	}
+
+	val = 1;
+	ret = setsockopt(sock, SOL_UDP, UDP_REPAIR, &val, sizeof(val));
+	if (ret < 0)
+		error(1, errno, "setsockopt udp_repair");
+
+	val = 0;
+	ret = setsockopt(sock, SOL_SOCKET, SO_PEEK_OFF, &val, sizeof(val));
+	if (ret < 0)
+		error(1, errno, "setsockopt so_peek_off");
+
+	ret = recvfrom(sock, dump->buf, BUF_SIZE / 2, MSG_PEEK,
+		       addr, &addr_len);
+	if (ret < 0)
+		error(1, errno, "dumping send queue");
+
+	ret = recvfrom(sock, dump->buf + BUF_SIZE / 2,
+		       BUF_SIZE - BUF_SIZE / 2, MSG_PEEK,
+		       addr, &addr_len);
+	if (ret < 0)
+		error(1, errno, "dumping send queue");
+
+	if (memcmp(dump->buf, send_buf, BUF_SIZE))
+		error(1, 0, "dump: data mismatch");
+
+	return dump;
+}
+
+void restore(int sock, struct udp_dump *dump, int is_udp4)
+{
+	struct sockaddr *addr;
+	int val;
+	unsigned int addr_len;
+
+	if (is_udp4) {
+		addr = (struct sockaddr *) &dump->addr_v4;
+		addr_len = sizeof(dump->addr_v4);
+	} else {
+		addr = (struct sockaddr *) &dump->addr_v6;
+		addr_len = sizeof(dump->addr_v6);
+	}
+
+	if (sendto(sock, dump->buf, BUF_SIZE, 0, addr, addr_len) < 0)
+		error(1, errno, "send data");
+
+	val = 0;
+	if (setsockopt(sock, SOL_UDP, UDP_CORK, &val, sizeof(val)) < 0)
+		error(1, errno, "setsockopt un-cork udp");
+}
+
+void run_test(int is_udp4_sock, int is_udp4_packet)
+{
+	int server_sock, client_sock, ret, val;
+	struct udp_dump *dump;
+	struct sockaddr *addr;
+	unsigned int addr_len;
+
+	if (is_udp4_packet) {
+		addr = (struct sockaddr *) &addr_v4;
+		addr_len = sizeof(addr_v4);
+	} else {
+		addr = (struct sockaddr *) &addr_v6;
+		addr_len = sizeof(addr_v6);
+	}
+
+	server_sock = udp_server(is_udp4_packet);
+	client_sock = create_corked_udp_client(is_udp4_sock);
+
+	ret = sendto(client_sock, send_buf, sizeof(send_buf), 0,
+	       addr, addr_len);
+	if (ret < 0)
+		error(1, errno, "send data");
+
+	dump = checkpoint(client_sock, is_udp4_sock);
+	close(client_sock);
+
+	client_sock = create_corked_udp_client(is_udp4_sock);
+	restore(client_sock, dump, is_udp4_sock);
+
+	val = 0;
+	setsockopt(client_sock, SOL_UDP, UDP_CORK, &val, sizeof(val));
+	server_recv(server_sock);
+
+	close(server_sock);
+	close(client_sock);
+}
+
+void init(void)
+{
+	addr_v4.sin_family	= AF_INET;
+	addr_v4.sin_port	= htons(PORT);
+	addr_v4.sin_addr.s_addr	= inet_addr("127.0.0.1");
+
+	addr_v6.sin6_family	= AF_INET6;
+	addr_v6.sin6_port	= htons(PORT);
+	inet_pton(AF_INET6, "::1", &addr_v6.sin6_addr);
+
+	memset(send_buf, 'A', BUF_SIZE / 2);
+	memset(send_buf + BUF_SIZE / 2, 'B', BUF_SIZE - BUF_SIZE / 2);
+}
+
+int main(void)
+{
+	init();
+	fprintf(stderr, "Test udp4 socket\n");
+	run_test(1, 1);
+	fprintf(stderr, "Test udp6 socket sending udp4 packet\n");
+	run_test(0, 1);
+	fprintf(stderr, "Test udp6 socket sending udp6 packet\n");
+	run_test(0, 0);
+	fprintf(stderr, "Ok\n");
+	return 0;
+}
-- 
2.17.1