1/* SPDX-License-Identifier: GPL-2.0 */
2
3#ifndef __LWT_HELPERS_H
4#define __LWT_HELPERS_H
5
6#include <time.h>
7#include <net/if.h>
8#include <linux/if_tun.h>
9#include <linux/icmp.h>
10
11#include "test_progs.h"
12
13#define log_err(MSG, ...) \
14	fprintf(stderr, "(%s:%d: errno: %s) " MSG "\n", \
15		__FILE__, __LINE__, strerror(errno), ##__VA_ARGS__)
16
17#define RUN_TEST(name)                                                        \
18	({                                                                    \
19		if (test__start_subtest(#name))                               \
20			if (ASSERT_OK(netns_create(), "netns_create")) {      \
21				struct nstoken *token = open_netns(NETNS);    \
22				if (ASSERT_OK_PTR(token, "setns")) {          \
23					test_ ## name();                      \
24					close_netns(token);                   \
25				}                                             \
26				netns_delete();                               \
27			}                                                     \
28	})
29
30static inline int netns_create(void)
31{
32	return system("ip netns add " NETNS);
33}
34
35static inline int netns_delete(void)
36{
37	return system("ip netns del " NETNS ">/dev/null 2>&1");
38}
39
40static int open_tuntap(const char *dev_name, bool need_mac)
41{
42	int err = 0;
43	struct ifreq ifr;
44	int fd = open("/dev/net/tun", O_RDWR);
45
46	if (!ASSERT_GT(fd, 0, "open(/dev/net/tun)"))
47		return -1;
48
49	ifr.ifr_flags = IFF_NO_PI | (need_mac ? IFF_TAP : IFF_TUN);
50	strncpy(ifr.ifr_name, dev_name, IFNAMSIZ - 1);
51	ifr.ifr_name[IFNAMSIZ - 1] = '\0';
52
53	err = ioctl(fd, TUNSETIFF, &ifr);
54	if (!ASSERT_OK(err, "ioctl(TUNSETIFF)")) {
55		close(fd);
56		return -1;
57	}
58
59	err = fcntl(fd, F_SETFL, O_NONBLOCK);
60	if (!ASSERT_OK(err, "fcntl(O_NONBLOCK)")) {
61		close(fd);
62		return -1;
63	}
64
65	return fd;
66}
67
68#define ICMP_PAYLOAD_SIZE     100
69
70/* Match an ICMP packet with payload len ICMP_PAYLOAD_SIZE */
71static int __expect_icmp_ipv4(char *buf, ssize_t len)
72{
73	struct iphdr *ip = (struct iphdr *)buf;
74	struct icmphdr *icmp = (struct icmphdr *)(ip + 1);
75	ssize_t min_header_len = sizeof(*ip) + sizeof(*icmp);
76
77	if (len < min_header_len)
78		return -1;
79
80	if (ip->protocol != IPPROTO_ICMP)
81		return -1;
82
83	if (icmp->type != ICMP_ECHO)
84		return -1;
85
86	return len == ICMP_PAYLOAD_SIZE + min_header_len;
87}
88
89typedef int (*filter_t) (char *, ssize_t);
90
91/* wait_for_packet - wait for a packet that matches the filter
92 *
93 * @fd: tun fd/packet socket to read packet
94 * @filter: filter function, returning 1 if matches
95 * @timeout: timeout to wait for the packet
96 *
97 * Returns 1 if a matching packet is read, 0 if timeout expired, -1 on error.
98 */
99static int wait_for_packet(int fd, filter_t filter, struct timeval *timeout)
100{
101	char buf[4096];
102	int max_retry = 5; /* in case we read some spurious packets */
103	fd_set fds;
104
105	FD_ZERO(&fds);
106	while (max_retry--) {
107		/* Linux modifies timeout arg... So make a copy */
108		struct timeval copied_timeout = *timeout;
109		ssize_t ret = -1;
110
111		FD_SET(fd, &fds);
112
113		ret = select(1 + fd, &fds, NULL, NULL, &copied_timeout);
114		if (ret <= 0) {
115			if (errno == EINTR)
116				continue;
117			else if (errno == EAGAIN || ret == 0)
118				return 0;
119
120			log_err("select failed");
121			return -1;
122		}
123
124		ret = read(fd, buf, sizeof(buf));
125
126		if (ret <= 0) {
127			log_err("read(dev): %ld", ret);
128			return -1;
129		}
130
131		if (filter && filter(buf, ret) > 0)
132			return 1;
133	}
134
135	return 0;
136}
137
138#endif /* __LWT_HELPERS_H */
139