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#include "common.h"
#include <stdarg.h>
#include <errno.h>
#include <signal.h>
#include <sys/wait.h>
#include <arpa/inet.h>
static pid_t latency_pid = -1;
bool
latency_running(void)
{
int socktrue = 1;
sockaddr_all addr;
int sock = socket(AF_INET, SOCK_DGRAM, 0);
assert(sock >= 0);
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (const void *) &socktrue, sizeof(socktrue));
setup_addr(&addr, "192.168.127.2", 0);
bool res;
if (bind(sock, &addr.generic, sizeof(addr)) == 0) {
res = true;
} else {
assert(errno == EADDRNOTAVAIL);
res = false;
}
close(sock);
return res;
}
void
launch_latency(const char *fmt, ...)
{
assert(latency_pid == -1);
while (latency_running()) {
system("killall latency > /dev/null 2> /dev/null");
usleep(2000);
}
char cmd[1024];
va_list ap;
strcpy(cmd, "exec ../latency ");
size_t cmd_len = strlen(cmd);
va_start(ap, fmt);
vsnprintf(cmd + cmd_len, sizeof(cmd) - cmd_len, fmt, ap);
va_end(ap);
printf("starting %s\n", cmd);
latency_pid = fork();
assert(latency_pid != -1);
if (latency_pid == 0) {
execlp("sh", "sh", "-c", cmd, NULL);
kill(getpid(), SIGKILL);
exit(1);
}
int count;
while (!latency_running()) {
usleep(2000);
assert(++count < 100);
}
usleep(50000);
}
static void
handle_alarm(int sig)
{
}
void
kill_latency(void)
{
assert(latency_pid != -1);
kill(latency_pid, SIGTERM);
// handle some timeout
signal(SIGALRM, handle_alarm);
alarm(1);
int status;
pid_t pid = waitpid(latency_pid, &status, 0);
alarm(0);
signal(SIGALRM, SIG_DFL);
assert(pid == latency_pid);
assert(WIFEXITED(status));
assert(WEXITSTATUS(status) == 0);
latency_pid = -1;
}
void
setup_addr(sockaddr_all *addr, const char *ip, int port)
{
struct in_addr inet;
assert(inet_aton(ip, &inet) == 1);
addr->inet.sin_family = AF_INET;
addr->inet.sin_addr = inet;
addr->inet.sin_port = htons(port);
}
void
create_udp_pair(int socks[2])
{
int sock;
int socktrue = 1;
sockaddr_all addr;
socklen_t addr_len;
int ports[2];
sock = socket(AF_INET, SOCK_DGRAM, 0);
assert(sock >= 0);
socks[0] = sock;
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (const void *) &socktrue, sizeof(socktrue));
setup_addr(&addr, "192.168.127.0", 0);
assert(bind(sock, &addr.generic, sizeof(addr)) == 0);
addr_len = sizeof(addr);
assert(getsockname(sock, &addr.generic, &addr_len) == 0);
ports[0] = ntohs(addr.inet.sin_port);
sock = socket(AF_INET, SOCK_DGRAM, 0);
assert(sock >= 0);
socks[1] = sock;
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (const void *) &socktrue, sizeof(socktrue));
setup_addr(&addr, "192.168.127.2", 0);
assert(bind(sock, &addr.generic, sizeof(addr)) == 0);
addr_len = sizeof(addr);
assert(getsockname(sock, &addr.generic, &addr_len) == 0);
ports[1] = ntohs(addr.inet.sin_port);
// make a pair from the above ones
setup_addr(&addr, "192.168.127.1", ports[1]);
assert(connect(socks[0], &addr.generic, sizeof(addr)) == 0);
setup_addr(&addr, "192.168.127.3", ports[0]);
assert(connect(socks[1], &addr.generic, sizeof(addr)) == 0);
}
void
close_udp_pair(int socks[2])
{
close(socks[0]);
close(socks[1]);
socks[0] = socks[1] = -1;
}
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