diff options
| -rw-r--r-- | networking/udhcp/Kbuild | 3 | ||||
| -rw-r--r-- | networking/udhcp/dhcpd.c | 265 | ||||
| -rw-r--r-- | networking/udhcp/dhcpd.h | 8 | ||||
| -rw-r--r-- | networking/udhcp/serverpacket.c | 283 |
4 files changed, 263 insertions, 296 deletions
diff --git a/networking/udhcp/Kbuild b/networking/udhcp/Kbuild index d1d3567..138a950 100644 --- a/networking/udhcp/Kbuild +++ b/networking/udhcp/Kbuild @@ -17,8 +17,7 @@ lib-$(CONFIG_UDHCPC) += dhcpc.o clientpacket.o clientsocket.o \ UDHCPC_NEEDS_ARPING-$(CONFIG_FEATURE_UDHCPC_ARPING) = y lib-$(UDHCPC_NEEDS_ARPING-y) += arpping.o -lib-$(CONFIG_UDHCPD) += dhcpd.o arpping.o files.o leases.o \ - serverpacket.o static_leases.o +lib-$(CONFIG_UDHCPD) += dhcpd.o arpping.o files.o leases.o static_leases.o lib-$(CONFIG_DUMPLEASES) += dumpleases.o lib-$(CONFIG_DHCPRELAY) += dhcprelay.o diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c index dc5d9ff..26fb304 100644 --- a/networking/udhcp/dhcpd.c +++ b/networking/udhcp/dhcpd.c @@ -1,13 +1,24 @@ /* 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. + * 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 <syslog.h> @@ -17,6 +28,254 @@ #include "options.h" +/* send a packet to gateway_nip using the kernel ip stack */ +static int send_packet_to_relay(struct dhcp_packet *dhcp_pkt) +{ + log1("Forwarding packet to relay"); + + return udhcp_send_kernel_packet(dhcp_pkt, + server_config.server_nip, SERVER_PORT, + dhcp_pkt->gateway_nip, SERVER_PORT); +} + +/* send a packet to a specific mac address and ip address by creating our own ip packet */ +static int send_packet_to_client(struct dhcp_packet *dhcp_pkt, int force_broadcast) +{ + const uint8_t *chaddr; + uint32_t ciaddr; + + // Was: + //if (force_broadcast) { /* broadcast */ } + //else if (dhcp_pkt->ciaddr) { /* unicast to dhcp_pkt->ciaddr */ } + //else if (dhcp_pkt->flags & htons(BROADCAST_FLAG)) { /* broadcast */ } + //else { /* unicast to dhcp_pkt->yiaddr */ } + // But this is wrong: yiaddr is _our_ idea what client's IP is + // (for example, from lease file). Client may not know that, + // and may not have UDP socket listening on that IP! + // We should never unicast to dhcp_pkt->yiaddr! + // dhcp_pkt->ciaddr, OTOH, comes from client's request packet, + // and can be used. + + if (force_broadcast + || (dhcp_pkt->flags & htons(BROADCAST_FLAG)) + || !dhcp_pkt->ciaddr + ) { + log1("Broadcasting packet to client"); + ciaddr = INADDR_BROADCAST; + chaddr = MAC_BCAST_ADDR; + } else { + log1("Unicasting packet to client ciaddr"); + ciaddr = dhcp_pkt->ciaddr; + chaddr = dhcp_pkt->chaddr; + } + + return udhcp_send_raw_packet(dhcp_pkt, + /*src*/ server_config.server_nip, SERVER_PORT, + /*dst*/ ciaddr, CLIENT_PORT, chaddr, + server_config.ifindex); +} + +/* send a dhcp packet, if force broadcast is set, the packet will be broadcast to the client */ +static int send_packet(struct dhcp_packet *dhcp_pkt, int force_broadcast) +{ + if (dhcp_pkt->gateway_nip) + return send_packet_to_relay(dhcp_pkt); + return send_packet_to_client(dhcp_pkt, force_broadcast); +} + +static void init_packet(struct dhcp_packet *packet, struct dhcp_packet *oldpacket, char type) +{ + udhcp_init_header(packet, type); + packet->xid = oldpacket->xid; + memcpy(packet->chaddr, oldpacket->chaddr, sizeof(oldpacket->chaddr)); + packet->flags = oldpacket->flags; + packet->gateway_nip = oldpacket->gateway_nip; + packet->ciaddr = oldpacket->ciaddr; + add_simple_option(packet->options, DHCP_SERVER_ID, server_config.server_nip); +} + +/* add in the bootp options */ +static void add_bootp_options(struct dhcp_packet *packet) +{ + packet->siaddr_nip = server_config.siaddr_nip; + if (server_config.sname) + strncpy((char*)packet->sname, server_config.sname, sizeof(packet->sname) - 1); + if (server_config.boot_file) + strncpy((char*)packet->file, server_config.boot_file, sizeof(packet->file) - 1); +} + +static uint32_t select_lease_time(struct dhcp_packet *packet) +{ + uint32_t lease_time_sec = server_config.max_lease_sec; + uint8_t *lease_time_opt = get_option(packet, DHCP_LEASE_TIME); + if (lease_time_opt) { + move_from_unaligned32(lease_time_sec, lease_time_opt); + lease_time_sec = ntohl(lease_time_sec); + if (lease_time_sec > server_config.max_lease_sec) + lease_time_sec = server_config.max_lease_sec; + if (lease_time_sec < server_config.min_lease_sec) + lease_time_sec = server_config.min_lease_sec; + } + return lease_time_sec; +} + +/* send a DHCP OFFER to a DHCP DISCOVER */ +static int send_offer(struct dhcp_packet *oldpacket) +{ + struct dhcp_packet packet; + uint32_t req_nip; + uint32_t lease_time_sec = server_config.max_lease_sec; + uint32_t static_lease_ip; + uint8_t *req_ip_opt; + const char *p_host_name; + struct option_set *curr; + struct in_addr addr; + + init_packet(&packet, oldpacket, DHCPOFFER); + + static_lease_ip = get_static_nip_by_mac(server_config.static_leases, oldpacket->chaddr); + + /* ADDME: if static, short circuit */ + if (!static_lease_ip) { + struct dyn_lease *lease; + + lease = find_lease_by_mac(oldpacket->chaddr); + /* The client is in our lease/offered table */ + if (lease) { + signed_leasetime_t tmp = lease->expires - time(NULL); + if (tmp >= 0) + lease_time_sec = tmp; + packet.yiaddr = lease->lease_nip; + } + /* Or the client has requested an IP */ + else if ((req_ip_opt = get_option(oldpacket, DHCP_REQUESTED_IP)) != NULL + /* (read IP) */ + && (move_from_unaligned32(req_nip, req_ip_opt), 1) + /* and the IP is in the lease range */ + && ntohl(req_nip) >= server_config.start_ip + && ntohl(req_nip) <= server_config.end_ip + /* and is not already taken/offered */ + && (!(lease = find_lease_by_nip(req_nip)) + /* or its taken, but expired */ + || is_expired_lease(lease)) + ) { + packet.yiaddr = req_nip; + } + /* Otherwise, find a free IP */ + else { + packet.yiaddr = find_free_or_expired_nip(oldpacket->chaddr); + } + + if (!packet.yiaddr) { + bb_error_msg("no IP addresses to give - OFFER abandoned"); + return -1; + } + p_host_name = (const char*) get_option(oldpacket, DHCP_HOST_NAME); + if (add_lease(packet.chaddr, packet.yiaddr, + server_config.offer_time, + p_host_name, + p_host_name ? (unsigned char)p_host_name[OPT_LEN - OPT_DATA] : 0 + ) == 0 + ) { + bb_error_msg("lease pool is full - OFFER abandoned"); + return -1; + } + lease_time_sec = select_lease_time(oldpacket); + } else { + /* It is a static lease... use it */ + packet.yiaddr = static_lease_ip; + } + + add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_sec)); + + curr = server_config.options; + while (curr) { + if (curr->data[OPT_CODE] != DHCP_LEASE_TIME) + add_option_string(packet.options, curr->data); + curr = curr->next; + } + + add_bootp_options(&packet); + + addr.s_addr = packet.yiaddr; + bb_info_msg("Sending OFFER of %s", inet_ntoa(addr)); + return send_packet(&packet, 0); +} + +static int send_NAK(struct dhcp_packet *oldpacket) +{ + struct dhcp_packet packet; + + init_packet(&packet, oldpacket, DHCPNAK); + + log1("Sending NAK"); + return send_packet(&packet, 1); +} + +static int send_ACK(struct dhcp_packet *oldpacket, uint32_t yiaddr) +{ + struct dhcp_packet packet; + struct option_set *curr; + uint32_t lease_time_sec; + struct in_addr addr; + const char *p_host_name; + + init_packet(&packet, oldpacket, DHCPACK); + packet.yiaddr = yiaddr; + + lease_time_sec = select_lease_time(oldpacket); + + add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_sec)); + + curr = server_config.options; + while (curr) { + if (curr->data[OPT_CODE] != DHCP_LEASE_TIME) + add_option_string(packet.options, curr->data); + curr = curr->next; + } + + add_bootp_options(&packet); + + addr.s_addr = packet.yiaddr; + bb_info_msg("Sending ACK to %s", inet_ntoa(addr)); + + if (send_packet(&packet, 0) < 0) + return -1; + + p_host_name = (const char*) get_option(oldpacket, DHCP_HOST_NAME); + add_lease(packet.chaddr, packet.yiaddr, + lease_time_sec, + p_host_name, + p_host_name ? (unsigned char)p_host_name[OPT_LEN - OPT_DATA] : 0 + ); + if (ENABLE_FEATURE_UDHCPD_WRITE_LEASES_EARLY) { + /* rewrite the file with leases at every new acceptance */ + write_leases(); + } + + return 0; +} + +static int send_inform(struct dhcp_packet *oldpacket) +{ + struct dhcp_packet packet; + struct option_set *curr; + + init_packet(&packet, oldpacket, DHCPACK); + + curr = server_config.options; + while (curr) { + if (curr->data[OPT_CODE] != DHCP_LEASE_TIME) + add_option_string(packet.options, curr->data); + curr = curr->next; + } + + add_bootp_options(&packet); + + return send_packet(&packet, 0); +} + + /* globals */ struct dyn_lease *g_leases; /* struct server_config_t server_config is in bb_common_bufsiz1 */ diff --git a/networking/udhcp/dhcpd.h b/networking/udhcp/dhcpd.h index db2d1c7..b55fd6c 100644 --- a/networking/udhcp/dhcpd.h +++ b/networking/udhcp/dhcpd.h @@ -124,14 +124,6 @@ void log_static_leases(struct static_lease **st_lease_pp) FAST_FUNC; #endif -/*** serverpacket.h ***/ - -int send_offer(struct dhcp_packet *oldpacket) FAST_FUNC; -int send_NAK(struct dhcp_packet *oldpacket) FAST_FUNC; -int send_ACK(struct dhcp_packet *oldpacket, uint32_t yiaddr) FAST_FUNC; -int send_inform(struct dhcp_packet *oldpacket) FAST_FUNC; - - /*** files.h ***/ void read_config(const char *file) FAST_FUNC; diff --git a/networking/udhcp/serverpacket.c b/networking/udhcp/serverpacket.c deleted file mode 100644 index b48e415..0000000 --- a/networking/udhcp/serverpacket.c +++ /dev/null @@ -1,283 +0,0 @@ -/* vi: set sw=4 ts=4: */ -/* serverpacket.c - * - * Construct and send DHCP server packets - * - * 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 "common.h" -#include "dhcpc.h" -#include "dhcpd.h" -#include "options.h" - - -/* send a packet to gateway_nip using the kernel ip stack */ -static int send_packet_to_relay(struct dhcp_packet *dhcp_pkt) -{ - log1("Forwarding packet to relay"); - - return udhcp_send_kernel_packet(dhcp_pkt, - server_config.server_nip, SERVER_PORT, - dhcp_pkt->gateway_nip, SERVER_PORT); -} - - -/* send a packet to a specific mac address and ip address by creating our own ip packet */ -static int send_packet_to_client(struct dhcp_packet *dhcp_pkt, int force_broadcast) -{ - const uint8_t *chaddr; - uint32_t ciaddr; - - // Was: - //if (force_broadcast) { /* broadcast */ } - //else if (dhcp_pkt->ciaddr) { /* unicast to dhcp_pkt->ciaddr */ } - //else if (dhcp_pkt->flags & htons(BROADCAST_FLAG)) { /* broadcast */ } - //else { /* unicast to dhcp_pkt->yiaddr */ } - // But this is wrong: yiaddr is _our_ idea what client's IP is - // (for example, from lease file). Client may not know that, - // and may not have UDP socket listening on that IP! - // We should never unicast to dhcp_pkt->yiaddr! - // dhcp_pkt->ciaddr, OTOH, comes from client's request packet, - // and can be used. - - if (force_broadcast - || (dhcp_pkt->flags & htons(BROADCAST_FLAG)) - || !dhcp_pkt->ciaddr - ) { - log1("Broadcasting packet to client"); - ciaddr = INADDR_BROADCAST; - chaddr = MAC_BCAST_ADDR; - } else { - log1("Unicasting packet to client ciaddr"); - ciaddr = dhcp_pkt->ciaddr; - chaddr = dhcp_pkt->chaddr; - } - - return udhcp_send_raw_packet(dhcp_pkt, - /*src*/ server_config.server_nip, SERVER_PORT, - /*dst*/ ciaddr, CLIENT_PORT, chaddr, - server_config.ifindex); -} - - -/* send a dhcp packet, if force broadcast is set, the packet will be broadcast to the client */ -static int send_packet(struct dhcp_packet *dhcp_pkt, int force_broadcast) -{ - if (dhcp_pkt->gateway_nip) - return send_packet_to_relay(dhcp_pkt); - return send_packet_to_client(dhcp_pkt, force_broadcast); -} - - -static void init_packet(struct dhcp_packet *packet, struct dhcp_packet *oldpacket, char type) -{ - udhcp_init_header(packet, type); - packet->xid = oldpacket->xid; - memcpy(packet->chaddr, oldpacket->chaddr, sizeof(oldpacket->chaddr)); - packet->flags = oldpacket->flags; - packet->gateway_nip = oldpacket->gateway_nip; - packet->ciaddr = oldpacket->ciaddr; - add_simple_option(packet->options, DHCP_SERVER_ID, server_config.server_nip); -} - - -/* add in the bootp options */ -static void add_bootp_options(struct dhcp_packet *packet) -{ - packet->siaddr_nip = server_config.siaddr_nip; - if (server_config.sname) - strncpy((char*)packet->sname, server_config.sname, sizeof(packet->sname) - 1); - if (server_config.boot_file) - strncpy((char*)packet->file, server_config.boot_file, sizeof(packet->file) - 1); -} - - -static uint32_t select_lease_time(struct dhcp_packet *packet) -{ - uint32_t lease_time_sec = server_config.max_lease_sec; - uint8_t *lease_time_opt = get_option(packet, DHCP_LEASE_TIME); - if (lease_time_opt) { - move_from_unaligned32(lease_time_sec, lease_time_opt); - lease_time_sec = ntohl(lease_time_sec); - if (lease_time_sec > server_config.max_lease_sec) - lease_time_sec = server_config.max_lease_sec; - if (lease_time_sec < server_config.min_lease_sec) - lease_time_sec = server_config.min_lease_sec; - } - return lease_time_sec; -} - - -/* send a DHCP OFFER to a DHCP DISCOVER */ -int FAST_FUNC send_offer(struct dhcp_packet *oldpacket) -{ - struct dhcp_packet packet; - uint32_t req_nip; - uint32_t lease_time_sec = server_config.max_lease_sec; - uint32_t static_lease_ip; - uint8_t *req_ip_opt; - const char *p_host_name; - struct option_set *curr; - struct in_addr addr; - - init_packet(&packet, oldpacket, DHCPOFFER); - - static_lease_ip = get_static_nip_by_mac(server_config.static_leases, oldpacket->chaddr); - - /* ADDME: if static, short circuit */ - if (!static_lease_ip) { - struct dyn_lease *lease; - - lease = find_lease_by_mac(oldpacket->chaddr); - /* The client is in our lease/offered table */ - if (lease) { - signed_leasetime_t tmp = lease->expires - time(NULL); - if (tmp >= 0) - lease_time_sec = tmp; - packet.yiaddr = lease->lease_nip; - } - /* Or the client has requested an IP */ - else if ((req_ip_opt = get_option(oldpacket, DHCP_REQUESTED_IP)) != NULL - /* (read IP) */ - && (move_from_unaligned32(req_nip, req_ip_opt), 1) - /* and the IP is in the lease range */ - && ntohl(req_nip) >= server_config.start_ip - && ntohl(req_nip) <= server_config.end_ip - /* and is not already taken/offered */ - && (!(lease = find_lease_by_nip(req_nip)) - /* or its taken, but expired */ - || is_expired_lease(lease)) - ) { - packet.yiaddr = req_nip; - } - /* Otherwise, find a free IP */ - else { - packet.yiaddr = find_free_or_expired_nip(oldpacket->chaddr); - } - - if (!packet.yiaddr) { - bb_error_msg("no IP addresses to give - OFFER abandoned"); - return -1; - } - p_host_name = (const char*) get_option(oldpacket, DHCP_HOST_NAME); - if (add_lease(packet.chaddr, packet.yiaddr, - server_config.offer_time, - p_host_name, - p_host_name ? (unsigned char)p_host_name[OPT_LEN - OPT_DATA] : 0 - ) == 0 - ) { - bb_error_msg("lease pool is full - OFFER abandoned"); - return -1; - } - lease_time_sec = select_lease_time(oldpacket); - } else { - /* It is a static lease... use it */ - packet.yiaddr = static_lease_ip; - } - - add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_sec)); - - curr = server_config.options; - while (curr) { - if (curr->data[OPT_CODE] != DHCP_LEASE_TIME) - add_option_string(packet.options, curr->data); - curr = curr->next; - } - - add_bootp_options(&packet); - - addr.s_addr = packet.yiaddr; - bb_info_msg("Sending OFFER of %s", inet_ntoa(addr)); - return send_packet(&packet, 0); -} - - -int FAST_FUNC send_NAK(struct dhcp_packet *oldpacket) -{ - struct dhcp_packet packet; - - init_packet(&packet, oldpacket, DHCPNAK); - - log1("Sending NAK"); - return send_packet(&packet, 1); -} - - -int FAST_FUNC send_ACK(struct dhcp_packet *oldpacket, uint32_t yiaddr) -{ - struct dhcp_packet packet; - struct option_set *curr; - uint32_t lease_time_sec; - struct in_addr addr; - const char *p_host_name; - - init_packet(&packet, oldpacket, DHCPACK); - packet.yiaddr = yiaddr; - - lease_time_sec = select_lease_time(oldpacket); - - add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_sec)); - - curr = server_config.options; - while (curr) { - if (curr->data[OPT_CODE] != DHCP_LEASE_TIME) - add_option_string(packet.options, curr->data); - curr = curr->next; - } - - add_bootp_options(&packet); - - addr.s_addr = packet.yiaddr; - bb_info_msg("Sending ACK to %s", inet_ntoa(addr)); - - if (send_packet(&packet, 0) < 0) - return -1; - - p_host_name = (const char*) get_option(oldpacket, DHCP_HOST_NAME); - add_lease(packet.chaddr, packet.yiaddr, - lease_time_sec, - p_host_name, - p_host_name ? (unsigned char)p_host_name[OPT_LEN - OPT_DATA] : 0 - ); - if (ENABLE_FEATURE_UDHCPD_WRITE_LEASES_EARLY) { - /* rewrite the file with leases at every new acceptance */ - write_leases(); - } - - return 0; -} - - -int FAST_FUNC send_inform(struct dhcp_packet *oldpacket) -{ - struct dhcp_packet packet; - struct option_set *curr; - - init_packet(&packet, oldpacket, DHCPACK); - - curr = server_config.options; - while (curr) { - if (curr->data[OPT_CODE] != DHCP_LEASE_TIME) - add_option_string(packet.options, curr->data); - curr = curr->next; - } - - add_bootp_options(&packet); - - return send_packet(&packet, 0); -} |