70 lines
1.6 KiB
C
70 lines
1.6 KiB
C
#include <stdio.h>
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#include <arpa/inet.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <malloc.h>
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#include <netdb.h>
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#include <string.h>
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#include <sys/time.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <signal.h>
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#include <stdarg.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <time.h>
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#include "control.h"
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int new_packet(short type, char *packet)
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{
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int id = (time(NULL) ^ (rand() * 1024*1024));
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*(short *)(packet + 0) = ntohs(0x9012);
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*(short *)(packet + 2) = ntohs(type);
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*(int *)(packet + 6) = ntohl(id);
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return 10;
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}
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int send_packet(int sockfd, int dest_ip, int dest_port, char *packet, int len)
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{
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struct sockaddr_in addr;
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*(short *)(packet + 4) = ntohs(len);
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memset(&addr, 0, sizeof(addr));
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addr.sin_family = AF_INET;
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*(int*)&addr.sin_addr = htonl(dest_ip);
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addr.sin_port = htons(dest_port);
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if (sendto(sockfd, packet, len, 0, (void *) &addr, sizeof(addr)) < 0)
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{
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perror("sendto");
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return 0;
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}
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return 1;
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}
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int read_packet(int sockfd, char *packet)
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{
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struct sockaddr_in addr;
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int alen = sizeof(addr);
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memset(&addr, 0, sizeof(addr));
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return recvfrom(sockfd, packet, 1400, 0, (void *) &addr, &alen);
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}
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void dump_packet(char *packet, FILE *stream)
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{
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if (htons(*(short *)(packet + 0)) != 0x9012)
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{
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fprintf(stream, "Invalid packet identifier %x\n", htons(*(short *)(packet + 0)));
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return;
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}
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fprintf(stream, "Control packet:\n");
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fprintf(stream, " Type: %d\n", htons(*(short *)(packet + 2)));
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fprintf(stream, " Length: %d\n", htons(*(short *)(packet + 4)));
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fprintf(stream, " Identifier: %x\n", htonl(*(int *)(packet + 6)));
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fprintf(stream, "\n");
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}
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