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 30 static inline int netns_create(void) 31 { 32 return system("ip netns add " NETNS); 33 } 34 35 static inline int netns_delete(void) 36 { 37 return system("ip netns del " NETNS ">/dev/null 2>&1"); 38 } 39 40 static 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 */ 71 static 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 89 typedef 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 */ 99 static 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