1 files changed, 226 insertions, 0 deletions

diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c
new file mode 100644
index 000000000..74380367f
--- /dev/null
+++ b/networking/udhcp/dhcpd.c
@@ -0,0 +1,226 @@
+/* vi: set sw=4 ts=4: */
+/* 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
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include "common.h"
+#include "dhcpd.h"
+#include "options.h"
+
+
+/* globals */
+struct dhcpOfferedAddr *leases;
+struct server_config_t server_config;
+
+
+int udhcpd_main(int argc, char *argv[])
+{
+        fd_set rfds;
+        struct timeval tv;
+        int server_socket = -1, bytes, retval, max_sock;
+        struct dhcpMessage packet;
+        uint8_t *state, *server_id, *requested;
+        uint32_t server_id_align, requested_align, static_lease_ip;
+        unsigned long timeout_end, num_ips;
+        struct option_set *option;
+        struct dhcpOfferedAddr *lease, static_lease;
+
+        read_config(argc < 2 ? DHCPD_CONF_FILE : argv[1]);
+
+        /* Start the log, sanitize fd's, and write a pid file */
+        udhcp_start_log_and_pid(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 */
+        num_ips = ntohl(server_config.end) - ntohl(server_config.start) + 1;
+        if (server_config.max_leases > num_ips) {
+                bb_error_msg("max_leases value (%lu) not sane, "
+                        "setting to %lu instead",
+                        server_config.max_leases, num_ips);
+                server_config.max_leases = num_ips;
+        }
+
+        leases = xzalloc(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;
+
+        if (!ENABLE_FEATURE_UDHCP_DEBUG)
+                udhcp_background(server_config.pidfile); /* hold lock during fork. */
+
+        /* 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) {
+                        server_socket = listen_socket(INADDR_ANY, SERVER_PORT, server_config.interface);
+                        if (server_socket < 0) {
+                                bb_perror_msg("FATAL: cannot create server socket");
+                                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("error on select");
+                        continue;
+                }
+
+                switch (udhcp_sp_read(&rfds)) {
+                case SIGUSR1:
+                        bb_info_msg("Received a SIGUSR1");
+                        write_leases();
+                        /* why not just reset the timeout, eh */
+                        timeout_end = time(0) + server_config.auto_time;
+                        continue;
+                case SIGTERM:
+                        bb_info_msg("Received a SIGTERM");
+                        return 0;
+                case 0: break;          /* no signal */
+                default: continue;      /* signal or error (probably EINTR) */
+                }
+
+                if ((bytes = udhcp_get_packet(&packet, server_socket)) < 0) { /* this waits for a packet - idle */
+                        if (bytes == -1 && errno != EINTR) {
+                                DEBUG("error on read, %s, reopening socket", strerror(errno));
+                                close(server_socket);
+                                server_socket = -1;
+                        }
+                        continue;
+                }
+
+                if ((state = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) {
+                        bb_error_msg("cannot 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) {
+                        bb_info_msg("Found static lease: %x", 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("Received DISCOVER");
+
+                        if (sendOffer(&packet) < 0) {
+                                bb_error_msg("send OFFER failed");
+                        }
+                        break;
+                case DHCPREQUEST:
+                        DEBUG("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("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("Received DECLINE");
+                        if (lease) {
+                                memset(lease->chaddr, 0, 16);
+                                lease->expires = time(0) + server_config.decline_time;
+                        }
+                        break;
+                case DHCPRELEASE:
+                        DEBUG("Received RELEASE");
+                        if (lease) lease->expires = time(0);
+                        break;
+                case DHCPINFORM:
+                        DEBUG("Received INFORM");
+                        send_inform(&packet);
+                        break;
+                default:
+                        bb_info_msg("Unsupported DHCP message (%02x) - ignoring", state[0]);
+                }
+        }
+
+        return 0;
+}