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/icmp.h>
9
10 #include "test_progs.h"
11
12 #define log_err(MSG, ...) \
13 fprintf(stderr, "(%s:%d: errno: %s) " MSG "\n", \
14 __FILE__, __LINE__, strerror(errno), ##__VA_ARGS__)
15
16 #define RUN_TEST(name) \
17 ({ \
18 if (test__start_subtest(#name)) \
19 if (ASSERT_OK(netns_create(), "netns_create")) { \
20 struct nstoken *token = open_netns(NETNS); \
21 if (ASSERT_OK_PTR(token, "setns")) { \
22 test_ ## name(); \
23 close_netns(token); \
24 } \
25 netns_delete(); \
26 } \
27 })
28
netns_create(void)29 static inline int netns_create(void)
30 {
31 return system("ip netns add " NETNS);
32 }
33
netns_delete(void)34 static inline int netns_delete(void)
35 {
36 return system("ip netns del " NETNS ">/dev/null 2>&1");
37 }
38
39 #define ICMP_PAYLOAD_SIZE 100
40
41 /* Match an ICMP packet with payload len ICMP_PAYLOAD_SIZE */
__expect_icmp_ipv4(char * buf,ssize_t len)42 static int __expect_icmp_ipv4(char *buf, ssize_t len)
43 {
44 struct iphdr *ip = (struct iphdr *)buf;
45 struct icmphdr *icmp = (struct icmphdr *)(ip + 1);
46 ssize_t min_header_len = sizeof(*ip) + sizeof(*icmp);
47
48 if (len < min_header_len)
49 return -1;
50
51 if (ip->protocol != IPPROTO_ICMP)
52 return -1;
53
54 if (icmp->type != ICMP_ECHO)
55 return -1;
56
57 return len == ICMP_PAYLOAD_SIZE + min_header_len;
58 }
59
60 typedef int (*filter_t) (char *, ssize_t);
61
62 /* wait_for_packet - wait for a packet that matches the filter
63 *
64 * @fd: tun fd/packet socket to read packet
65 * @filter: filter function, returning 1 if matches
66 * @timeout: timeout to wait for the packet
67 *
68 * Returns 1 if a matching packet is read, 0 if timeout expired, -1 on error.
69 */
wait_for_packet(int fd,filter_t filter,struct timeval * timeout)70 static int wait_for_packet(int fd, filter_t filter, struct timeval *timeout)
71 {
72 char buf[4096];
73 int max_retry = 5; /* in case we read some spurious packets */
74 fd_set fds;
75
76 FD_ZERO(&fds);
77 while (max_retry--) {
78 /* Linux modifies timeout arg... So make a copy */
79 struct timeval copied_timeout = *timeout;
80 ssize_t ret = -1;
81
82 FD_SET(fd, &fds);
83
84 ret = select(1 + fd, &fds, NULL, NULL, &copied_timeout);
85 if (ret <= 0) {
86 if (errno == EINTR)
87 continue;
88 else if (errno == EAGAIN || ret == 0)
89 return 0;
90
91 log_err("select failed");
92 return -1;
93 }
94
95 ret = read(fd, buf, sizeof(buf));
96
97 if (ret <= 0) {
98 log_err("read(dev): %ld", ret);
99 return -1;
100 }
101
102 if (filter && filter(buf, ret) > 0)
103 return 1;
104 }
105
106 return 0;
107 }
108
109 #endif /* __LWT_HELPERS_H */
110