/* Mac-Telnet - Connect to RouterOS routers via MAC address Copyright (C) 2010, Håkon Nessjøen This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include #include #include #include #include #include "mactelnet.h" #include "config.h" int main(int argc, char **argv) { int sock,result; int optval = 1; struct sockaddr_in si_me, si_remote; unsigned char buff[MT_PACKET_LEN]; unsigned short nameLen = 0; unsigned char name[MT_MNDP_MAX_NAME_LENGTH + 1]; unsigned char mac[ETH_ALEN]; /* Open a UDP socket handle */ sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); /* Set initialize address/port */ memset((char *) &si_me, 0, sizeof(si_me)); si_me.sin_family = AF_INET; si_me.sin_port = htons(MT_MNDP_PORT); si_me.sin_addr.s_addr = htonl(INADDR_ANY); /* Bind to specified address/port */ if (bind(sock, (struct sockaddr *)&si_me, sizeof(si_me))==-1) { fprintf(stderr, "Error binding to %s:%d\n", inet_ntoa(si_me.sin_addr), MT_MNDP_PORT); return 1; } /* Write informative message to STDERR to make it easier to use the output in simple scripts */ fprintf(stderr, "Searching for MikroTik routers... Abort with CTRL+C.\n"); /* Set the socket to allow sending broadcast packets */ if (setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &optval, sizeof (optval))==-1) { fprintf(stderr, "Unable to send broadcast packets: Operating in receive only mode.\n"); } else { /* Request routers identify themselves */ unsigned int message = 0; memset((char *) &si_remote, 0, sizeof(si_remote)); si_remote.sin_family = AF_INET; si_remote.sin_port = htons(MT_MNDP_PORT); si_remote.sin_addr.s_addr = htonl(INADDR_BROADCAST); if (sendto (sock, &message, sizeof (message), 0, (struct sockaddr *)&si_remote, sizeof(si_remote))==-1) { fprintf(stderr, "Unable to send broadcast packet: Operating in receive only mode.\n"); } } while(1) { /* Wait for a UDP packet */ result = recvfrom(sock, buff, MT_PACKET_LEN, 0, 0, 0); if (result < 0) { fprintf(stderr, "Error occured. aborting\n"); exit(1); } /* Check for valid packet length */ if (result < 18) { continue; } /* Fetch length of Identifier string */ memcpy(&nameLen, buff+16,2); nameLen = (nameLen >> 8) | ((nameLen&0xff)<<8); /* Enforce maximum name length */ nameLen = nameLen < sizeof(name) ? nameLen : MT_MNDP_MAX_NAME_LENGTH; /* Read Identifier string */ memcpy(&name, buff+18, nameLen); /* Append zero */ name[nameLen] = 0; /* Read source MAC address */ memcpy(&mac, buff+8, ETH_ALEN); /* Print it */ printf("%17s %s\n", ether_ntoa((struct ether_addr *)mac), name); } /* We'll never get here.. */ return 0; }