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/*
* Dummy server sending alternating bytes to all clients.
*
* This program can be used to trigger mobility events in the hICN forwarder, to
* switch from WiFi to LTE and back, at regular intervals.
*
* Test server using nc: nc -4kvul localhost 9533
*/
#include <arpa/inet.h> // inet_ntop
#include <errno.h> // EINTR,. ..
#include <netinet/in.h> // INET_ADDRSTRLEN, INET6_ADDRSTRLEN
#include <stdio.h>
#include <inttypes.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/timerfd.h>
#include <sys/un.h> // sockaddr_un
#include <unistd.h> // fcntl
#include <fcntl.h> // fcntl
#define MS2US(x) (x * 1000)
/**
* \brief Main function
*/
int main(int argc, char **argv) {
int rc;
if (argc != 4) {
fprintf(stderr, "Usage: %s IP PORT INTERVAL\n", argv[0]);
fprintf(stderr, "\n");
fprintf(stderr, " IP Target hostname\n");
fprintf(stderr, " PORT Target port\n");
fprintf(stderr, " INTERVAL Interval between mobility events (in ms)\n");
fprintf(stderr, "\n");
exit(EXIT_FAILURE);
}
int interval = atoi(argv[3]);
int fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (fd < 0) {
perror("socket");
goto ERR_SOCKET;
}
struct sockaddr_in addr;
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = inet_addr(argv[1]);
addr.sin_port = htons(atoi(argv[2]));
if (connect(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
perror("connect");
goto ERR_CONNECT;
}
unsigned state = 0;
char buf[1];
for (;;) {
usleep(MS2US(interval));
buf[0] = state;
rc = send(fd, buf, 1, 0);
if (rc < 0) {
if (errno == ECONNREFUSED) {
continue;
}
perror("send");
goto ERR_SEND;
}
state = 1 - state;
}
close(fd);
exit(EXIT_SUCCESS);
ERR_SEND:
ERR_CONNECT:
close(fd);
ERR_SOCKET:
exit(EXIT_FAILURE);
}
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