summaryrefslogtreecommitdiff
path: root/networking/udhcp/dhcpd.c
diff options
context:
space:
mode:
Diffstat (limited to 'networking/udhcp/dhcpd.c')
-rw-r--r--networking/udhcp/dhcpd.c287
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;
+}
+
generated by cgit v1.1 at 2024-12-28 16:58:35 +0000