From c5fcf7179a83ef65c86c6a4a390029149e518649 Mon Sep 17 00:00:00 2001 From: Franciszek Malinka Date: Tue, 5 Oct 2021 21:49:54 +0200 Subject: Duzy commit ze smieciami --- Semestr 4/sieci/pracownia1/traceroute.c | 240 -------------------------------- 1 file changed, 240 deletions(-) delete mode 100644 Semestr 4/sieci/pracownia1/traceroute.c (limited to 'Semestr 4/sieci/pracownia1/traceroute.c') diff --git a/Semestr 4/sieci/pracownia1/traceroute.c b/Semestr 4/sieci/pracownia1/traceroute.c deleted file mode 100644 index 0e51c14..0000000 --- a/Semestr 4/sieci/pracownia1/traceroute.c +++ /dev/null @@ -1,240 +0,0 @@ -/* Pracownia programistyczna nr 1 - traceroute - * Imię i nazwisko: Franciszek Malinka - * Nr indeksu: 316093 - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#define MAX_TTL 30 -#define MESSAGES_PER_TTL 3 -#define NO_MESSAGES -1 -#define TOO_FEW_MESSAGES -2137 - -void print_as_bytes (unsigned char* buff, ssize_t length) -{ - for (ssize_t i = 0; i < length; i++, buff++) - printf ("%.2x ", *buff); -} - -void debug_received(uint8_t *buffer, struct sockaddr_in *sender, int packet_len) { - char ip_str[20]; - inet_ntop(AF_INET, &(sender->sin_addr), ip_str, sizeof(ip_str)); - - printf("IP packet with ICMP content from: %s\n", ip_str); - struct ip* ip_header = (struct ip*) buffer; - ssize_t ip_header_len = 4 * ip_header->ip_hl; - - printf ("IP header: "); - print_as_bytes (buffer, ip_header_len); - printf("\n"); - - printf ("IP data: "); - print_as_bytes (buffer + ip_header_len, packet_len - ip_header_len); - printf("\n\n"); -} - -struct sockaddr_in get_sockaddr_from_ip(char *ip) { - struct sockaddr_in sock; - bzero(&sock, sizeof(sock)); - sock.sin_family = AF_INET; - if (!inet_pton(AF_INET, ip, &sock.sin_addr)) { - fprintf(stderr, "Given ip is invalid: %s\n", ip); - exit(EXIT_FAILURE); - } - return sock; -} - -int create_raw_icmp_socket() { - int sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP); - if (sockfd < 0) { - fprintf(stderr, "socket error: %s\n", strerror(errno)); - exit(EXIT_FAILURE); - } - return sockfd; -} - -uint16_t compute_icmp_checksum(const void *buff, int length) -{ - uint32_t sum; - const uint16_t* ptr = buff; - assert (length % 2 == 0); - for (sum = 0; length > 0; length -= 2) - sum += *ptr++; - sum = (sum >> 16) + (sum & 0xffff); - return (uint16_t)(~(sum + (sum >> 16))); -} - -struct icmp create_icmp_header(uint16_t seq) { - struct icmp header; - header.icmp_type = ICMP_ECHO; - header.icmp_code = 0; - header.icmp_id = (uint16_t)getpid(); - header.icmp_seq = seq; - header.icmp_cksum = 0; - header.icmp_cksum = compute_icmp_checksum( - (uint16_t*)&header, sizeof(header)); - - return header; -} - -void send_icmp_packet(int sockfd, struct sockaddr_in *destination, int ttl) { - struct icmp header = create_icmp_header(ttl); - setsockopt(sockfd, IPPROTO_IP, IP_TTL, &ttl, sizeof(int)); - - ssize_t bytes_sent = sendto( - sockfd, - &header, - sizeof(header), - 0, - (struct sockaddr*)destination, - sizeof(*destination) - ); - if (bytes_sent == -1) { - fprintf(stderr, "Error while sending ICMP packet: %s\n", strerror(errno)); - exit(EXIT_FAILURE); - } -} - -/* Return ip address of the sender of recceived package */ -ssize_t recv_packet(int sockfd, struct sockaddr_in *sender, uint8_t *buffer) { - socklen_t sender_len = sizeof(*sender); - ssize_t packet_len = recvfrom(sockfd, buffer, IP_MAXPACKET, 0, - (struct sockaddr*)sender, &sender_len); - - if (packet_len == -1) { - fprintf(stderr, "Error while recieving a packet: %s\n", strerror(errno)); - exit(EXIT_FAILURE); - } - return packet_len; -} - -void send_icmp_requests(int sockfd, struct sockaddr_in *destination, int ttl, int tries) { - for (int i = 0; i < tries; i++) { - send_icmp_packet(sockfd, destination, ttl); - } -} - -int try_select(int sockfd, struct timeval *tv) { - fd_set descriptors; - FD_ZERO(&descriptors); - FD_SET(sockfd, &descriptors); - return select(sockfd+1, &descriptors, NULL, NULL, tv); -} - -void pretty_print_router(int ttl, struct in_addr *senders, float mean_wait_time, int messages_received) { - char ip_str[20]; - printf("%d.\t", ttl); - if (messages_received == 0) { - printf("*\n"); - } - else { - for (int i = 0; i < messages_received; i++) { - bool already_printed = false; - for (int j = 0; j < i; j++) { - if (senders[i].s_addr == senders[j].s_addr) { - already_printed = true; - break; - } - } - if (already_printed) continue; - inet_ntop(AF_INET, senders + i, ip_str, sizeof(ip_str)); - printf("%-15s ", ip_str); - } - if (messages_received < MESSAGES_PER_TTL) printf("\t???\n"); - else printf("\t%.2fms\n", mean_wait_time); - } -} - -// This function decapsulates important data from the IMCP replies -void get_important_data(uint8_t *buffer, uint8_t *code, uint16_t *id, uint16_t *seq) { - struct ip* ip_header = (struct ip*) buffer; - ssize_t offset = 4 * ip_header->ip_hl; - *code = ((struct icmp *)(buffer + offset))->icmp_type; - if (*code != ICMP_ECHOREPLY && *code != ICMP_TIMXCEED) { - return; - } else if (*code == ICMP_TIMXCEED) { - offset += ICMP_MINLEN; - offset += 4 * ((struct ip *)(buffer + offset))->ip_hl; - *seq = ((struct icmp *)(buffer + offset))->icmp_seq; - *id = ((struct icmp *)(buffer + offset))->icmp_id; - } else { - *seq = ((struct icmp *)(buffer + offset))->icmp_seq; - *id = ((struct icmp *)(buffer + offset))->icmp_id; - } -} - -// timeout in milliseconds -float get_replies(int sockfd, long timeout, int ttl, int *messages_received, struct in_addr *senders) { - struct sockaddr_in sender; - uint8_t buffer[IP_MAXPACKET]; - int ready; - long mean_wait_time = 0; - struct timeval tv; tv.tv_sec = timeout / 1000; tv.tv_usec = 0; - *messages_received = 0; - - while ((ready = try_select(sockfd, &tv))) { - if (ready < 0) { - fprintf(stderr, "Select error: %s\n", strerror(errno)); - exit(EXIT_FAILURE); - } - - recv_packet(sockfd, &sender, buffer); - uint8_t icmp_code = 0; - uint16_t seq = 0, id = 0; - - get_important_data(buffer, &icmp_code, &id, &seq); - if (seq == ttl) { - senders[(*messages_received)++] = sender.sin_addr; - mean_wait_time += timeout * 1000 - tv.tv_usec; - - if (*messages_received == MESSAGES_PER_TTL) break; - } - } - // changing from microseconds to miliseconds - return (float)mean_wait_time / 3.0 / 1000.0; -} - -// Core of the program. -void traceroute(struct sockaddr_in *destination) { - int sockfd = create_raw_icmp_socket(), messages_received = 0; - struct in_addr senders[MESSAGES_PER_TTL]; - - for (int ttl = 1; ttl <= MAX_TTL; ++ttl) { - send_icmp_requests(sockfd, destination, ttl, MESSAGES_PER_TTL); - float mean_wait_time = get_replies(sockfd, 1000, ttl, &messages_received, senders); - pretty_print_router(ttl, senders, mean_wait_time, messages_received); - - // what if our packet branched and we got to the destination faster by some path? - // we gotta make a loop, not an if - for (int i = 0; i < messages_received; i++) { - if (senders[i].s_addr == destination->sin_addr.s_addr) { - return; - } - } - } -} - -int main(int argc, char * argv[]) { - if (argc < 2) { - fprintf(stderr, "Usage:\n\t%s [host ip]\n", argv[0]); - return 1; - } - - struct sockaddr_in destination = get_sockaddr_from_ip(argv[1]); - fprintf(stdout, "traceroute to %s, %d hops max\n", argv[1], MAX_TTL); - traceroute(&destination); - - return 0; -} \ No newline at end of file -- cgit v1.2.3