X-Git-Url: https://git.grml.org/?a=blobdiff_plain;f=udhcp%2Fdhcpd.c;fp=udhcp%2Fdhcpd.c;h=767f9b013afd9dd99a4eae4ef0e324813097a71c;hb=d0c93c365e33f6970a0417dff7009a4a4fe2a3b1;hp=0000000000000000000000000000000000000000;hpb=184a9d3153e3fae4fa1ea20a186c12e9c0a83db2;p=grml-terminalserver.git diff --git a/udhcp/dhcpd.c b/udhcp/dhcpd.c new file mode 100644 index 0000000..767f9b0 --- /dev/null +++ b/udhcp/dhcpd.c @@ -0,0 +1,275 @@ +/* dhcpd.c + * + * udhcp Server + * Copyright (C) 1999 Matthew Ramsay + * Chris Trew + * + * Rewrite by Russ Dill July 2001 + * + * 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., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "dhcpd.h" +#include "arpping.h" +#include "socket.h" +#include "options.h" +#include "files.h" +#include "serverpacket.h" +#include "common.h" +#include "signalpipe.h" +#include "static_leases.h" + + +/* globals */ +struct dhcpOfferedAddr *leases; +struct server_config_t server_config; + + +#ifdef COMBINED_BINARY +int udhcpd_main(int argc, char *argv[]) +#else +int main(int argc, char *argv[]) +#endif +{ + fd_set rfds; + struct timeval tv; + int server_socket = -1; + int bytes, retval; + struct dhcpMessage packet; + uint8_t *state; + uint8_t *server_id, *requested; + uint32_t server_id_align, requested_align; + unsigned long timeout_end; + struct option_set *option; + struct dhcpOfferedAddr *lease; + struct dhcpOfferedAddr static_lease; + int max_sock; + unsigned long num_ips; + + uint32_t static_lease_ip; + + memset(&server_config, 0, sizeof(struct server_config_t)); + read_config(argc < 2 ? DHCPD_CONF_FILE : argv[1]); + + /* Start the log, sanitize fd's, and write a pid file */ + start_log_and_pid("udhcpd", server_config.pidfile); + + if ((option = find_option(server_config.options, DHCP_LEASE_TIME))) { + memcpy(&server_config.lease, option->data + 2, 4); + server_config.lease = ntohl(server_config.lease); + } + else server_config.lease = LEASE_TIME; + + /* Sanity check */ + // Let's try to fix http://bugs.debian.org/341139 (ericvb@debian.org - 16/12/05) + //num_ips = ntohl(server_config.end) - ntohl(server_config.start); + num_ips = ntohl(server_config.end) - ntohl(server_config.start) + 1; + if (server_config.max_leases > num_ips) { + LOG(LOG_ERR, "max_leases value (%lu) not sane, " + "setting to %lu instead", + server_config.max_leases, num_ips); + server_config.max_leases = num_ips; + } + + leases = xcalloc(server_config.max_leases, sizeof(struct dhcpOfferedAddr)); + read_leases(server_config.lease_file); + + if (read_interface(server_config.interface, &server_config.ifindex, + &server_config.server, server_config.arp) < 0) + return 1; + +#ifndef UDHCP_DEBUG + background(server_config.pidfile); /* hold lock during fork. */ +#endif + + /* Setup the signal pipe */ + udhcp_sp_setup(); + + timeout_end = time(0) + server_config.auto_time; + while(1) { /* loop until universe collapses */ + + if (server_socket < 0) + if ((server_socket = listen_socket(INADDR_ANY, SERVER_PORT, server_config.interface)) < 0) { + LOG(LOG_ERR, "FATAL: couldn't create server socket, %m"); + return 2; + } + + max_sock = udhcp_sp_fd_set(&rfds, server_socket); + if (server_config.auto_time) { + tv.tv_sec = timeout_end - time(0); + tv.tv_usec = 0; + } + if (!server_config.auto_time || tv.tv_sec > 0) { + retval = select(max_sock + 1, &rfds, NULL, NULL, + server_config.auto_time ? &tv : NULL); + } else retval = 0; /* If we already timed out, fall through */ + + if (retval == 0) { + write_leases(); + timeout_end = time(0) + server_config.auto_time; + continue; + } else if (retval < 0 && errno != EINTR) { + DEBUG(LOG_INFO, "error on select"); + continue; + } + + switch (udhcp_sp_read(&rfds)) { + case SIGUSR1: + LOG(LOG_INFO, "Received a SIGUSR1"); + write_leases(); + /* why not just reset the timeout, eh */ + timeout_end = time(0) + server_config.auto_time; + continue; + case SIGTERM: + LOG(LOG_INFO, "Received a SIGTERM"); + return 0; + case 0: break; /* no signal */ + default: continue; /* signal or error (probably EINTR) */ + } + + if ((bytes = get_packet(&packet, server_socket)) < 0) { /* this waits for a packet - idle */ + if (bytes == -1 && errno != EINTR) { + DEBUG(LOG_INFO, "error on read, %m, reopening socket"); + close(server_socket); + server_socket = -1; + } + continue; + } + + if ((state = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) { + DEBUG(LOG_ERR, "couldn't get option from packet, ignoring"); + continue; + } + + /* Look for a static lease */ + static_lease_ip = getIpByMac(server_config.static_leases, &packet.chaddr); + + if(static_lease_ip) + { + printf("Found static lease: %x\n", static_lease_ip); + + memcpy(&static_lease.chaddr, &packet.chaddr, 16); + static_lease.yiaddr = static_lease_ip; + static_lease.expires = 0; + + lease = &static_lease; + + } + else + { + lease = find_lease_by_chaddr(packet.chaddr); + } + + switch (state[0]) { + case DHCPDISCOVER: + DEBUG(LOG_INFO,"received DISCOVER"); + + if (sendOffer(&packet) < 0) { + LOG(LOG_ERR, "send OFFER failed"); + } + break; + case DHCPREQUEST: + DEBUG(LOG_INFO, "received REQUEST"); + + requested = get_option(&packet, DHCP_REQUESTED_IP); + server_id = get_option(&packet, DHCP_SERVER_ID); + + if (requested) memcpy(&requested_align, requested, 4); + if (server_id) memcpy(&server_id_align, server_id, 4); + + if (lease) { + if (server_id) { + /* SELECTING State */ + DEBUG(LOG_INFO, "server_id = %08x", ntohl(server_id_align)); + if (server_id_align == server_config.server && requested && + requested_align == lease->yiaddr) { + sendACK(&packet, lease->yiaddr); + } + } else { + if (requested) { + /* INIT-REBOOT State */ + if (lease->yiaddr == requested_align) + sendACK(&packet, lease->yiaddr); + else sendNAK(&packet); + } else { + /* RENEWING or REBINDING State */ + if (lease->yiaddr == packet.ciaddr) + sendACK(&packet, lease->yiaddr); + else { + /* don't know what to do!!!! */ + sendNAK(&packet); + } + } + } + + /* what to do if we have no record of the client */ + } else if (server_id) { + /* SELECTING State */ + + } else if (requested) { + /* INIT-REBOOT State */ + if ((lease = find_lease_by_yiaddr(requested_align))) { + if (lease_expired(lease)) { + /* probably best if we drop this lease */ + memset(lease->chaddr, 0, 16); + /* make some contention for this address */ + } else sendNAK(&packet); + } else if (requested_align < server_config.start || + requested_align > server_config.end) { + sendNAK(&packet); + } /* else remain silent */ + + } else { + /* RENEWING or REBINDING State */ + } + break; + case DHCPDECLINE: + DEBUG(LOG_INFO,"received DECLINE"); + if (lease) { + memset(lease->chaddr, 0, 16); + lease->expires = time(0) + server_config.decline_time; + } + break; + case DHCPRELEASE: + DEBUG(LOG_INFO,"received RELEASE"); + if (lease) lease->expires = time(0); + break; + case DHCPINFORM: + DEBUG(LOG_INFO,"received INFORM"); + send_inform(&packet); + break; + default: + LOG(LOG_WARNING, "unsupported DHCP message (%02x) -- ignoring", state[0]); + } + } + + return 0; +} +