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#include <stdio.h>
#include <errno.h>
#include <strings.h>
#include <string.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include "router_addr.h"
#include "utils.h"
#define SERVER_PORT 54321
#define TURN_LEN_S 5
#define TURN_LEN_MS (1000 * TURN_LEN_S)
#define TURN_LEN_US (1000000 * TURN_LEN_S)
uint16_t read_configuration(struct router_addr** networks) {
uint16_t n;
scanf("%hd", &n);
*networks = malloc(n * sizeof(struct router_addr));
for (int i = 0; i < n; i++) {
char addr[20];
char _dist[10];
uint16_t dist;
scanf(" %s %s %hd", addr, _dist, &dist);
(*networks)[i] = stora(addr);
(*networks)[i].distance = dist;
}
return n;
}
void listen_for_routers(int sockfd, int timeout, int networks_number, struct router_addr *netowrks) {
printf("Listening for %dms.\n", timeout);
while (poll_socket_modify_timeout(sockfd, &timeout)) {
printf("Poll returned, remaining timeout: %dms.\n", timeout);
recv_and_print(sockfd, networks_number, netowrks);
}
printf("Finished listening\n\n");
}
int send_distance_vector(int sockfd, struct in_addr network) {
struct sockaddr_in network_address;
bzero (&network_address, sizeof(network_address));
network_address.sin_family = AF_INET;
network_address.sin_port = htons(SERVER_PORT);
network_address.sin_addr = network;
char* message = "Hello server! My name is S1\n";
ssize_t message_len = strlen(message);
int result;
char addr[20];
inet_ntop(AF_INET, &network, addr, sizeof(addr));
printf("Sending datagram to %s\n", addr);
if ((result = sendto(sockfd, message, message_len, 0, (struct sockaddr*) &network_address, sizeof(network_address))) != message_len) {
fprintf(stderr, "sendto error: %s\n", strerror(errno));
}
}
void propagate_distance_vector(int sockfd, int networks_number, struct router_addr *networks) {
printf("Propagating distance vector\n");
for (int i = 0; i < networks_number; i++) {
struct in_addr broadcast_address = get_broadcast_address(networks[i]);
send_distance_vector(sockfd, broadcast_address);
}
printf("Distance vector propagated.\n\n");
}
void router_loop(int sockfd, int networks_number, struct router_addr *networks) {
printf("Starting the router loop...\n");
for (;;) {
listen_for_routers(sockfd, TURN_LEN_MS, networks_number, networks);
propagate_distance_vector(sockfd, networks_number, networks);
}
}
int main() {
struct router_addr* networks;
int n = read_configuration(&networks);
for (int i = 0; i < n; i++) {
pretty_print(networks[i]);
}
int sockfd = get_socket();
bind_to_port(sockfd, SERVER_PORT);
router_loop(sockfd, n, networks);
close(sockfd);
free(networks);
}
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