added full udhcp integration

1 files changed, 287 insertions, 0 deletions

diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c
new file mode 100644
index 0000000..6c16dfe
--- /dev/null
+++ b/networking/udhcp/dhcpd.c
@@ -0,0 +1,287 @@
+/* dhcpd.c
+ *
+ * udhcp Server
+ * Copyright (C) 1999 Matthew Ramsay <matthewr@moreton.com.au>
+ *			Chris Trew <ctrew@moreton.com.au>
+ *
+ * Rewrite by Russ Dill <Russ.Dill@asu.edu> 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 <fcntl.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <signal.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <time.h>
+#include <sys/time.h>
+
+#include "debug.h"
+#include "dhcpd.h"
+#include "arpping.h"
+#include "socket.h"
+#include "options.h"
+#include "files.h"
+#include "leases.h"
+#include "packet.h"
+#include "serverpacket.h"
+#include "pidfile.h"
+
+
+/* globals */
+struct dhcpOfferedAddr *leases;
+struct server_config_t server_config;
+static int signal_pipe[2];
+
+/* Exit and cleanup */
+static void exit_server(int retval)
+{
+	pidfile_delete(server_config.pidfile);
+	CLOSE_LOG();
+	exit(retval);
+}
+
+
+/* Signal handler */
+static void signal_handler(int sig)
+{
+	if (send(signal_pipe[1], &sig, sizeof(sig), MSG_DONTWAIT) < 0) {
+		LOG(LOG_ERR, "Could not send signal: %s", 
+			strerror(errno));
+	}
+}
+
+
+#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;
+	unsigned char *state;
+	unsigned char *server_id, *requested;
+	u_int32_t server_id_align, requested_align;
+	unsigned long timeout_end;
+	struct option_set *option;
+	struct dhcpOfferedAddr *lease;
+	int pid_fd;
+	int max_sock;
+	int sig;
+	
+	OPEN_LOG("udhcpd");
+	LOG(LOG_INFO, "udhcp server (v%s) started", VERSION);
+
+	memset(&server_config, 0, sizeof(struct server_config_t));
+	
+	if (argc < 2)
+		read_config(DHCPD_CONF_FILE);
+	else read_config(argv[1]);
+
+	pid_fd = pidfile_acquire(server_config.pidfile);
+	pidfile_write_release(pid_fd);
+
+	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;
+	
+	leases = malloc(sizeof(struct dhcpOfferedAddr) * server_config.max_leases);
+	memset(leases, 0, sizeof(struct dhcpOfferedAddr) * server_config.max_leases);
+	read_leases(server_config.lease_file);
+
+	if (read_interface(server_config.interface, &server_config.ifindex,
+			   &server_config.server, server_config.arp) < 0)
+		exit_server(1);
+
+#ifndef DEBUGGING
+	pid_fd = pidfile_acquire(server_config.pidfile); /* hold lock during fork. */
+	if (daemon(0, 0) == -1) {
+		perror("fork");
+		exit_server(1);
+	}
+	pidfile_write_release(pid_fd);
+#endif
+
+
+	socketpair(AF_UNIX, SOCK_STREAM, 0, signal_pipe);
+	signal(SIGUSR1, signal_handler);
+	signal(SIGTERM, signal_handler);
+
+	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, %s", strerror(errno));
+				exit_server(0);
+			}			
+
+		FD_ZERO(&rfds);
+		FD_SET(server_socket, &rfds);
+		FD_SET(signal_pipe[0], &rfds);
+		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) {
+			max_sock = server_socket > signal_pipe[0] ? server_socket : signal_pipe[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;
+		}
+		
+		if (FD_ISSET(signal_pipe[0], &rfds)) {
+			if (read(signal_pipe[0], &sig, sizeof(sig)) < 0)
+				continue; /* probably just EINTR */
+			switch (sig) {
+			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");
+				exit_server(0);
+			}
+		}
+
+		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, %s, reopening socket", strerror(errno));
+				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;
+		}
+		
+		/* ADDME: look for a static lease */
+		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) { /*ADDME: or static 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;
+}
+