diff options
Diffstat (limited to 'Semestr 4/sieci/pracownia2/router.c')
-rw-r--r-- | Semestr 4/sieci/pracownia2/router.c | 212 |
1 files changed, 0 insertions, 212 deletions
diff --git a/Semestr 4/sieci/pracownia2/router.c b/Semestr 4/sieci/pracownia2/router.c deleted file mode 100644 index 79754b3..0000000 --- a/Semestr 4/sieci/pracownia2/router.c +++ /dev/null @@ -1,212 +0,0 @@ -#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 <poll.h> -#include <time.h> -#include <unistd.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) -#define NS_TO_MS(X) ((long)(X) / (long)1000000) -#define S_TO_MS(X) ((long)(X) * (long)1000) - -struct router_addr { - struct in_addr addr; - uint16_t distance; - uint8_t netmask; -}; - -struct in_addr get_broadcast_address(struct router_addr ra) { - struct in_addr result = ra.addr; - /* bitshift by more than 31 is UB */ - if (ra.netmask < 32) { - result.s_addr |= ~((1<<ra.netmask) - 1); - } - return result; -} - -void pretty_print(struct router_addr ra) { - char ip_addr[20]; - inet_ntop(AF_INET, &ra.addr, ip_addr, sizeof(ip_addr)); - printf("%s/%d distance %d\n", ip_addr, ra.netmask, ra.distance); -} - -/* converts string of IP with netmask in CIDR notation to router_addr */ -struct router_addr stora(char *str) { - struct router_addr result; - char addr[20]; - size_t ip_preffix = strcspn(str, "/"); - - strncpy(addr, str, strlen(str)); - addr[ip_preffix] = 0; - inet_pton(AF_INET, addr, &(result.addr)); - result.netmask = atoi(str + ip_preffix + 1); - return result; -} - -int get_socket() { - int sockfd = socket(AF_INET, SOCK_DGRAM, 0); - if (sockfd < 0) { - fprintf(stderr, "Socket error: %s\n", strerror(errno)); - exit(EXIT_FAILURE); - } - return sockfd; -} - -void bind_to_port(int sockfd, uint16_t port) { - struct sockaddr_in server_address; - bzero(&server_address, sizeof(server_address)); - server_address.sin_family = AF_INET; - server_address.sin_port = htons(port); - server_address.sin_addr.s_addr = htonl(INADDR_ANY); - if (bind(sockfd, (struct sockaddr*)&server_address, sizeof(server_address)) < 0) { - fprintf(stderr, "Bind error: %s\n", strerror(errno)); - exit(EXIT_FAILURE); - } - - int broadcastPermission = 1; - setsockopt (sockfd, SOL_SOCKET, SO_BROADCAST, (void *)&broadcastPermission, sizeof(broadcastPermission)); -} - -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; -} - -long get_time_interval(struct timespec start, struct timespec finish) { - return S_TO_MS(finish.tv_sec - start.tv_sec) + NS_TO_MS(finish.tv_nsec - start.tv_nsec); -} - -int poll_modify_timeout(struct pollfd *fds, nfds_t nfd, int *timeout) { - if (*timeout < 0) { - fprintf(stderr, "poll_modify_timeout: timeout is negative.\n"); - exit(EXIT_FAILURE); - } - - struct timespec start; - clock_gettime(CLOCK_REALTIME, &start); - int result = poll(fds, nfd, *timeout); - - if (result == -1) { - fprintf(stderr, "poll error: %s\n", strerror(errno)); - exit(EXIT_FAILURE); - } - if (result == 0) { - *timeout = 0; - return 0; - } - struct timespec finish; - clock_gettime(CLOCK_REALTIME, &finish); - *timeout -= get_time_interval(start, finish); - printf("Timeout: %dms, time waiting: %ldms.\n", *timeout, get_time_interval(start, finish)); - return result; -} - -/* For debug purposes only */ -void recv_and_print(int sockfd, int networks_number, struct router_addr *networks) { - struct sockaddr_in sender; - socklen_t sender_len = sizeof(sender); - uint8_t buffer[IP_MAXPACKET + 1]; - ssize_t datagram_len = recvfrom(sockfd, buffer, IP_MAXPACKET, 0, - (struct sockaddr*)&sender, &sender_len); - if (datagram_len < 0) { - fprintf(stderr, "recvfrom error: %s\n", strerror(errno)); - exit(EXIT_FAILURE); - } - for (int i = 0; i < networks_number; i++) { - if (networks[i].addr.s_addr == sender.sin_addr.s_addr) { - return; - } - } - - char sender_ip_str[20]; - inet_ntop(AF_INET, &(sender.sin_addr), sender_ip_str, sizeof(sender_ip_str)); - printf("Received UDP packet from IP address: %s, port %d\n", - sender_ip_str, ntohs(sender.sin_port)); - - buffer[datagram_len] = 0; - printf("%ld-byte message: +%s+\n", datagram_len, buffer); - -} - -void listen_for_routers(int sockfd, int timeout, int networks_number, struct router_addr *netowrks) { - printf("Listening for %dms.\n", timeout); - struct pollfd fds; - fds.fd = sockfd; - fds.events = POLLIN; - fds.revents = 0; - while (poll_modify_timeout(&fds, 1, &timeout)) { - printf("Poll returned, remaining timeout: %dms.\n", timeout); - recv_and_print(sockfd, networks_number, netowrks); - } - printf("Finished listening\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)); - // return EXIT_FAILURE; - } -} - -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"); -} - -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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