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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LWT_HELPERS_H
#define __LWT_HELPERS_H
#include <time.h>
#include <net/if.h>
#include <linux/if_tun.h>
#include <linux/icmp.h>
#include "test_progs.h"
#define log_err(MSG, ...) \
fprintf(stderr, "(%s:%d: errno: %s) " MSG "\n", \
__FILE__, __LINE__, strerror(errno), ##__VA_ARGS__)
#define RUN_TEST(name) \
({ \
if (test__start_subtest(#name)) \
if (ASSERT_OK(netns_create(), "netns_create")) { \
struct nstoken *token = open_netns(NETNS); \
if (ASSERT_OK_PTR(token, "setns")) { \
test_ ## name(); \
close_netns(token); \
} \
netns_delete(); \
} \
})
#define NETNS "ns_lwt"
static inline int netns_create(void)
{
return system("ip netns add " NETNS);
}
static inline int netns_delete(void)
{
return system("ip netns del " NETNS ">/dev/null 2>&1");
}
static int open_tuntap(const char *dev_name, bool need_mac)
{
int err = 0;
struct ifreq ifr;
int fd = open("/dev/net/tun", O_RDWR);
if (!ASSERT_GT(fd, 0, "open(/dev/net/tun)"))
return -1;
ifr.ifr_flags = IFF_NO_PI | (need_mac ? IFF_TAP : IFF_TUN);
strncpy(ifr.ifr_name, dev_name, IFNAMSIZ - 1);
ifr.ifr_name[IFNAMSIZ - 1] = '\0';
err = ioctl(fd, TUNSETIFF, &ifr);
if (!ASSERT_OK(err, "ioctl(TUNSETIFF)")) {
close(fd);
return -1;
}
err = fcntl(fd, F_SETFL, O_NONBLOCK);
if (!ASSERT_OK(err, "fcntl(O_NONBLOCK)")) {
close(fd);
return -1;
}
return fd;
}
#define ICMP_PAYLOAD_SIZE 100
/* Match an ICMP packet with payload len ICMP_PAYLOAD_SIZE */
static int __expect_icmp_ipv4(char *buf, ssize_t len)
{
struct iphdr *ip = (struct iphdr *)buf;
struct icmphdr *icmp = (struct icmphdr *)(ip + 1);
ssize_t min_header_len = sizeof(*ip) + sizeof(*icmp);
if (len < min_header_len)
return -1;
if (ip->protocol != IPPROTO_ICMP)
return -1;
if (icmp->type != ICMP_ECHO)
return -1;
return len == ICMP_PAYLOAD_SIZE + min_header_len;
}
typedef int (*filter_t) (char *, ssize_t);
/* wait_for_packet - wait for a packet that matches the filter
*
* @fd: tun fd/packet socket to read packet
* @filter: filter function, returning 1 if matches
* @timeout: timeout to wait for the packet
*
* Returns 1 if a matching packet is read, 0 if timeout expired, -1 on error.
*/
static int wait_for_packet(int fd, filter_t filter, struct timeval *timeout)
{
char buf[4096];
int max_retry = 5; /* in case we read some spurious packets */
fd_set fds;
FD_ZERO(&fds);
while (max_retry--) {
/* Linux modifies timeout arg... So make a copy */
struct timeval copied_timeout = *timeout;
ssize_t ret = -1;
FD_SET(fd, &fds);
ret = select(1 + fd, &fds, NULL, NULL, &copied_timeout);
if (ret <= 0) {
if (errno == EINTR)
continue;
else if (errno == EAGAIN || ret == 0)
return 0;
log_err("select failed");
return -1;
}
ret = read(fd, buf, sizeof(buf));
if (ret <= 0) {
log_err("read(dev): %ld", ret);
return -1;
}
if (filter && filter(buf, ret) > 0)
return 1;
}
return 0;
}
#endif /* __LWT_HELPERS_H */
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