An access controller for man doors at our facility. It receives Wiegand signals from a keypad/card reader and activates a relay to open the door. Access codes are stored in EEPROM. The active code list is updated from TFTP on a local server.
Dependencies: 24LCxx_I2C CardReader USBHOST
DHCPOptions.cpp
- Committer:
- acesrobertm
- Date:
- 2017-09-25
- Revision:
- 0:a56239ae90c2
File content as of revision 0:a56239ae90c2:
#include "DHCPOptions.h" int DHCPOptions::getOptions(char* tftp_server, const char* mac_address, const uint32_t timeout) { char mac_bin[DHCP_CHADDR_SIZE + 1] = {0}; // Initialize the hardware address array to zeros. int bind_result; DHCPPacket pkt, rec_pkt; // Generate binary version of the MAC string. macStrToBin(mac_bin, mac_address); SocketAddress dhcp_addr(DHCP_BROADCAST_ADDRESS, DHCP_SERVER_PORT); m_sock.open(m_eth); m_sock.set_timeout(timeout); bind_result = m_sock.bind(DHCP_CLIENT_PORT); if (bind_result < 0) { printf("DHCP Port Binding Failed: %d\n", bind_result); return -1; // DHCP port bind failed. } // Construct a DHCP DISCOVER packet pkt.op = DHCP_OP_REQUEST; pkt.htype = DHCP_HTYPE; pkt.hlen = DHCP_HLEN; pkt.hops = DHCP_HOPS; pkt.xid = htonl(rand()); pkt.secs = htons(DHCP_SECS); pkt.flags = htons(DHCP_FLAGS); pkt.ciaddr = htonl(DHCP_CIADDR); pkt.yiaddr = htonl(DHCP_YIADDR); pkt.siaddr = htonl(DHCP_SIADDR); pkt.giaddr = htonl(DHCP_GIADDR); // MAC address with padding - 16 bytes total memcpy(pkt.chaddr, mac_bin, DHCP_CHADDR_SIZE); memset(pkt.sname, 0, DHCP_SNAME_SIZE); memset(pkt.file, 0, DHCP_FILE_SIZE); // Options List pkt.magic = htonl(DHCP_MAGIC_COOKIE); pkt.op_mtype = 53; pkt.mtype_len = 1; pkt.mtype = 1; char discover_options[] = {DHCP_PREQLIST, 1, DHCP_OPTION_TFTPSERVER, DHCP_OPTION_STOP}; memcpy(pkt.options, discover_options, sizeof(discover_options)); // Send read request int bytes_sent = m_sock.sendto(dhcp_addr, (char*)&pkt, sizeof(DHCPPacket)); if (bytes_sent < 0) { printf("DHCP Discover Failed: %d\n", bytes_sent); return -2; // DHCP Discover send failed. } else { //printf("Sent: %d\n", bytes_sent); } // Get data packet from the DHCP server int bytes_received = m_sock.recvfrom(&dhcp_addr, (char*)&rec_pkt, sizeof(DHCPPacket)); if (bytes_received < 0) { printf("DHCP Offer Failed: %d\n", bytes_received); return -3; // UDP packet recevie failed. } else { //printf("Received: %d\n", bytes_received); } if (decodeOptions(tftp_server, rec_pkt) < 0) { printf("Failed to find the TFTP server option.\n"); return -4; // Failed to find the TFTP server name option from the DHCP offer response packet. } m_sock.close(); return 0; } int DHCPOptions::decodeOptions(char* tftp_server, DHCPPacket& pkt) { char* dhcp_options = pkt.options; int optionIndex = 0; int optionLength = 0; while (optionIndex < DHCP_OPTIONS_SIZE && dhcp_options[optionIndex] != DHCP_OPTION_STOP) { // Get the length of the current DHCP option field. optionLength = dhcp_options[optionIndex + 1]; // Check for the TFTP server option code. if (dhcp_options[optionIndex] == DHCP_OPTION_TFTPSERVER) { // Copy the TFTP server string to the output string. memcpy(tftp_server, dhcp_options + optionIndex + 2, optionLength); return 0; } // Move to the next option. optionIndex += 2 + optionLength; } return -1; // Failed to find the DHCP option. } int DHCPOptions::macStrToBin(char* macBin, const char* macStr) { if (strlen(macStr) != MAC_STRING_LENGTH) { return -1; // Invalid MAC string } else { for (int byteIndex = 0; byteIndex < 6; byteIndex++) { macBin[byteIndex] = (charToNum(macStr[byteIndex * 3]) * 16) + charToNum(macStr[(byteIndex * 3) + 1]); } } return 0; } unsigned char DHCPOptions::charToNum(const char input) { if(input >= '0' && input <= '9') { return input - '0'; } if(input >= 'A' && input <= 'F') { return input - 'A' + 10; } if(input >= 'a' && input <= 'f') { return input - 'a' + 10; } return 0; }