1// SPDX-License-Identifier: GPL-2.0
2
3#define _GNU_SOURCE
4
5#include <errno.h>
6#include <fcntl.h>
7#include <stdio.h>
8#include <stdlib.h>
9#include <string.h>
10#include <unistd.h>
11#include <linux/if.h>
12#include <linux/if_tun.h>
13#include <linux/netlink.h>
14#include <linux/rtnetlink.h>
15#include <sys/ioctl.h>
16#include <sys/socket.h>
17
18#include "../kselftest_harness.h"
19
20static int tun_attach(int fd, char *dev)
21{
22	struct ifreq ifr;
23
24	memset(&ifr, 0, sizeof(ifr));
25	strcpy(ifr.ifr_name, dev);
26	ifr.ifr_flags = IFF_ATTACH_QUEUE;
27
28	return ioctl(fd, TUNSETQUEUE, (void *) &ifr);
29}
30
31static int tun_detach(int fd, char *dev)
32{
33	struct ifreq ifr;
34
35	memset(&ifr, 0, sizeof(ifr));
36	strcpy(ifr.ifr_name, dev);
37	ifr.ifr_flags = IFF_DETACH_QUEUE;
38
39	return ioctl(fd, TUNSETQUEUE, (void *) &ifr);
40}
41
42static int tun_alloc(char *dev)
43{
44	struct ifreq ifr;
45	int fd, err;
46
47	fd = open("/dev/net/tun", O_RDWR);
48	if (fd < 0) {
49		fprintf(stderr, "can't open tun: %s\n", strerror(errno));
50		return fd;
51	}
52
53	memset(&ifr, 0, sizeof(ifr));
54	strcpy(ifr.ifr_name, dev);
55	ifr.ifr_flags = IFF_TAP | IFF_NAPI | IFF_MULTI_QUEUE;
56
57	err = ioctl(fd, TUNSETIFF, (void *) &ifr);
58	if (err < 0) {
59		fprintf(stderr, "can't TUNSETIFF: %s\n", strerror(errno));
60		close(fd);
61		return err;
62	}
63	strcpy(dev, ifr.ifr_name);
64	return fd;
65}
66
67static int tun_delete(char *dev)
68{
69	struct {
70		struct nlmsghdr  nh;
71		struct ifinfomsg ifm;
72		unsigned char    data[64];
73	} req;
74	struct rtattr *rta;
75	int ret, rtnl;
76
77	rtnl = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
78	if (rtnl < 0) {
79		fprintf(stderr, "can't open rtnl: %s\n", strerror(errno));
80		return 1;
81	}
82
83	memset(&req, 0, sizeof(req));
84	req.nh.nlmsg_len = NLMSG_ALIGN(NLMSG_LENGTH(sizeof(req.ifm)));
85	req.nh.nlmsg_flags = NLM_F_REQUEST;
86	req.nh.nlmsg_type = RTM_DELLINK;
87
88	req.ifm.ifi_family = AF_UNSPEC;
89
90	rta = (struct rtattr *)(((char *)&req) + NLMSG_ALIGN(req.nh.nlmsg_len));
91	rta->rta_type = IFLA_IFNAME;
92	rta->rta_len = RTA_LENGTH(IFNAMSIZ);
93	req.nh.nlmsg_len += rta->rta_len;
94	memcpy(RTA_DATA(rta), dev, IFNAMSIZ);
95
96	ret = send(rtnl, &req, req.nh.nlmsg_len, 0);
97	if (ret < 0)
98		fprintf(stderr, "can't send: %s\n", strerror(errno));
99	ret = (unsigned int)ret != req.nh.nlmsg_len;
100
101	close(rtnl);
102	return ret;
103}
104
105FIXTURE(tun)
106{
107	char ifname[IFNAMSIZ];
108	int fd, fd2;
109};
110
111FIXTURE_SETUP(tun)
112{
113	memset(self->ifname, 0, sizeof(self->ifname));
114
115	self->fd = tun_alloc(self->ifname);
116	ASSERT_GE(self->fd, 0);
117
118	self->fd2 = tun_alloc(self->ifname);
119	ASSERT_GE(self->fd2, 0);
120}
121
122FIXTURE_TEARDOWN(tun)
123{
124	if (self->fd >= 0)
125		close(self->fd);
126	if (self->fd2 >= 0)
127		close(self->fd2);
128}
129
130TEST_F(tun, delete_detach_close) {
131	EXPECT_EQ(tun_delete(self->ifname), 0);
132	EXPECT_EQ(tun_detach(self->fd, self->ifname), -1);
133	EXPECT_EQ(errno, 22);
134}
135
136TEST_F(tun, detach_delete_close) {
137	EXPECT_EQ(tun_detach(self->fd, self->ifname), 0);
138	EXPECT_EQ(tun_delete(self->ifname), 0);
139}
140
141TEST_F(tun, detach_close_delete) {
142	EXPECT_EQ(tun_detach(self->fd, self->ifname), 0);
143	close(self->fd);
144	self->fd = -1;
145	EXPECT_EQ(tun_delete(self->ifname), 0);
146}
147
148TEST_F(tun, reattach_delete_close) {
149	EXPECT_EQ(tun_detach(self->fd, self->ifname), 0);
150	EXPECT_EQ(tun_attach(self->fd, self->ifname), 0);
151	EXPECT_EQ(tun_delete(self->ifname), 0);
152}
153
154TEST_F(tun, reattach_close_delete) {
155	EXPECT_EQ(tun_detach(self->fd, self->ifname), 0);
156	EXPECT_EQ(tun_attach(self->fd, self->ifname), 0);
157	close(self->fd);
158	self->fd = -1;
159	EXPECT_EQ(tun_delete(self->ifname), 0);
160}
161
162TEST_HARNESS_MAIN
163