/*
route.c -- routing
- Copyright (C) 2000-2002 Ivo Timmermans <ivo@o2w.nl>,
- 2000-2002 Guus Sliepen <guus@sliepen.eu.org>
+ Copyright (C) 2000-2003 Ivo Timmermans <ivo@o2w.nl>,
+ 2000-2003 Guus Sliepen <guus@sliepen.eu.org>
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
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: route.c,v 1.1.2.45 2002/09/09 21:25:07 guus Exp $
+ $Id: route.c,v 1.1.2.61 2003/07/18 12:21:03 guus Exp $
*/
-#include "config.h"
+#include "system.h"
-#ifdef HAVE_SYS_PARAM_H
-#include <sys/param.h>
-#endif
-#include <sys/socket.h>
-#include <netinet/in.h>
-#ifdef HAVE_NET_IF_H
-#include <net/if.h>
-#endif
#ifdef HAVE_NET_ETHERNET_H
#include <net/ethernet.h>
#endif
-#ifdef HAVE_NETINET_IN_SYSTM_H
-#include <netinet/in_systm.h>
+#ifdef HAVE_NET_IF_ARP_H
+#include <net/if_arp.h>
#endif
+#ifdef HAVE_NETINET_IP_ICMP_H
+#include <netinet/ip_icmp.h>
+#endif
+#ifdef HAVE_NETINET_IP6_H
#include <netinet/ip6.h>
+#endif
+#ifdef HAVE_NETINET_ICMP6_H
#include <netinet/icmp6.h>
+#endif
+#ifdef HAVE_NETINET_IF_ETHER_H
#include <netinet/if_ether.h>
-#include <utils.h>
-#include <xalloc.h>
-#include <syslog.h>
-#include <string.h>
-#ifdef HAVE_INTTYPES_H
-#include <inttypes.h>
#endif
-#include <avl_tree.h>
-
-#include "net.h"
+#include "avl_tree.h"
#include "connection.h"
-#include "subnet.h"
-#include "route.h"
-#include "protocol.h"
#include "device.h"
-
-#include "system.h"
-
-#ifndef ETHER_ADDR_LEN
-#define ETHER_ADDR_LEN 6
-#endif
+#include "ethernet.h"
+#include "ipv4.h"
+#include "ipv6.h"
+#include "logger.h"
+#include "net.h"
+#include "protocol.h"
+#include "route.h"
+#include "subnet.h"
+#include "utils.h"
int routing_mode = RMODE_ROUTER;
int priorityinheritance = 0;
int macexpire = 600;
-subnet_t mymac;
+int overwrite_mac = 0;
+mac_t mymac = {{0xFE, 0xFD, 0, 0, 0, 0}};
-void learn_mac(mac_t * address)
+/* RFC 1071 */
+
+static uint16_t inet_checksum(void *data, int len, uint16_t prevsum)
+{
+ uint16_t *p = data;
+ uint32_t checksum = prevsum ^ 0xFFFF;
+
+ while(len >= 2) {
+ checksum += *p++;
+ len -= 2;
+ }
+
+ if(len)
+ checksum += *(unsigned char *)p;
+
+ while(checksum >> 16)
+ checksum = (checksum & 0xFFFF) + (checksum >> 16);
+
+ return ~checksum;
+}
+
+static int ratelimit(void) {
+ static time_t lasttime = 0;
+
+ if(lasttime == now)
+ return 1;
+
+ lasttime = now;
+ return 0;
+}
+
+static void learn_mac(mac_t *address)
{
subnet_t *subnet;
avl_node_t *node;
/* If we don't know this MAC address yet, store it */
if(!subnet || subnet->owner != myself) {
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_INFO, _("Learned new MAC address %hx:%hx:%hx:%hx:%hx:%hx"),
+ ifdebug(TRAFFIC) logger(LOG_INFO, _("Learned new MAC address %hx:%hx:%hx:%hx:%hx:%hx"),
address->x[0], address->x[1], address->x[2], address->x[3],
address->x[4], address->x[5]);
next = node->next;
s = (subnet_t *) node->data;
if(s->type == SUBNET_MAC && s->net.mac.lastseen && s->net.mac.lastseen + macexpire < now) {
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_INFO, _("MAC address %hx:%hx:%hx:%hx:%hx:%hx expired"),
+ ifdebug(TRAFFIC) logger(LOG_INFO, _("MAC address %hx:%hx:%hx:%hx:%hx:%hx expired"),
s->net.mac.address.x[0], s->net.mac.address.x[1],
s->net.mac.address.x[2], s->net.mac.address.x[3],
s->net.mac.address.x[4], s->net.mac.address.x[5]);
}
}
-node_t *route_mac(vpn_packet_t * packet)
+static node_t *route_mac(vpn_packet_t *packet)
{
subnet_t *subnet;
/* Learn source address */
- learn_mac((mac_t *) (&packet->data[6]));
+ learn_mac((mac_t *)(&packet->data[6]));
/* Lookup destination address */
- subnet = lookup_subnet_mac((mac_t *) (&packet->data[0]));
+ subnet = lookup_subnet_mac((mac_t *)(&packet->data[0]));
if(subnet)
return subnet->owner;
return NULL;
}
-node_t *route_ipv4(vpn_packet_t * packet)
+/* RFC 792 */
+
+static void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code)
+{
+ struct ip *hdr;
+ struct icmp *icmp;
+
+ struct in_addr ip_src;
+ struct in_addr ip_dst;
+ uint32_t oldlen;
+
+ if(ratelimit())
+ return;
+
+ cp();
+
+ hdr = (struct ip *)(packet->data + 14);
+ icmp = (struct icmp *)(packet->data + 14 + 20);
+
+ /* Remember original source and destination */
+
+ memcpy(&ip_src, &hdr->ip_src, 4);
+ memcpy(&ip_dst, &hdr->ip_dst, 4);
+ oldlen = packet->len - 14;
+
+ if(oldlen >= IP_MSS - sizeof(*hdr) - sizeof(*icmp))
+ oldlen = IP_MSS - sizeof(*hdr) - sizeof(*icmp);
+
+ /* Copy first part of original contents to ICMP message */
+
+ memmove(&icmp->icmp_ip, hdr, oldlen);
+
+ /* Fill in IPv4 header */
+
+ hdr->ip_v = 4;
+ hdr->ip_hl = sizeof(*hdr) / 4;
+ hdr->ip_tos = 0;
+ hdr->ip_len = htons(20 + 8 + oldlen);
+ hdr->ip_id = 0;
+ hdr->ip_off = 0;
+ hdr->ip_ttl = 255;
+ hdr->ip_p = IPPROTO_ICMP;
+ hdr->ip_sum = 0;
+ memcpy(&hdr->ip_src, &ip_dst, 4);
+ memcpy(&hdr->ip_dst, &ip_src, 4);
+
+ hdr->ip_sum = inet_checksum(hdr, 20, ~0);
+
+ /* Fill in ICMP header */
+
+ icmp->icmp_type = ICMP_DEST_UNREACH;
+ icmp->icmp_code = code;
+ icmp->icmp_cksum = 0;
+
+ icmp->icmp_cksum = inet_checksum(icmp, 8 + oldlen, ~0);
+
+ packet->len = 14 + 20 + 8 + oldlen;
+
+ write_packet(packet);
+}
+
+static node_t *route_ipv4(vpn_packet_t *packet)
{
subnet_t *subnet;
subnet = lookup_subnet_ipv4((ipv4_t *) & packet->data[30]);
if(!subnet) {
- if(debug_lvl >= DEBUG_TRAFFIC) {
- syslog(LOG_WARNING, _("Cannot route packet: unknown IPv4 destination address %d.%d.%d.%d"),
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: unknown IPv4 destination address %d.%d.%d.%d"),
packet->data[30], packet->data[31], packet->data[32],
packet->data[33]);
- }
+ route_ipv4_unreachable(packet, ICMP_NET_UNKNOWN);
return NULL;
}
+
+ if(!subnet->owner->status.reachable)
+ route_ipv4_unreachable(packet, ICMP_NET_UNREACH);
return subnet->owner;
}
-node_t *route_ipv6(vpn_packet_t * packet)
+/* RFC 2463 */
+
+static void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code)
+{
+ struct ip6_hdr *hdr;
+ struct icmp6_hdr *icmp;
+ uint16_t checksum;
+
+ struct {
+ struct in6_addr ip6_src; /* source address */
+ struct in6_addr ip6_dst; /* destination address */
+ uint32_t length;
+ uint32_t next;
+ } pseudo;
+
+ if(ratelimit())
+ return;
+
+ cp();
+
+ hdr = (struct ip6_hdr *)(packet->data + 14);
+ icmp = (struct icmp6_hdr *)(packet->data + 14 + sizeof(*hdr));
+
+ /* Remember original source and destination */
+
+ memcpy(&pseudo.ip6_src, &hdr->ip6_dst, 16);
+ memcpy(&pseudo.ip6_dst, &hdr->ip6_src, 16);
+ pseudo.length = ntohs(hdr->ip6_plen) + sizeof(*hdr);
+
+ if(pseudo.length >= IP_MSS - sizeof(*hdr) - sizeof(*icmp))
+ pseudo.length = IP_MSS - sizeof(*hdr) - sizeof(*icmp);
+
+ /* Copy first part of original contents to ICMP message */
+
+ memmove(((char *)icmp) + sizeof(*icmp), hdr, pseudo.length);
+
+ /* Fill in IPv6 header */
+
+ hdr->ip6_flow = htonl(0x60000000UL);
+ hdr->ip6_plen = htons(sizeof(*icmp) + pseudo.length);
+ hdr->ip6_nxt = IPPROTO_ICMPV6;
+ hdr->ip6_hlim = 255;
+ memcpy(&hdr->ip6_dst, &pseudo.ip6_dst, 16);
+ memcpy(&hdr->ip6_src, &pseudo.ip6_src, 16);
+
+ /* Fill in ICMP header */
+
+ icmp->icmp6_type = ICMP6_DST_UNREACH;
+ icmp->icmp6_code = code;
+ icmp->icmp6_cksum = 0;
+
+ /* Create pseudo header */
+
+ pseudo.length = htonl(sizeof(*icmp) + pseudo.length);
+ pseudo.next = htonl(IPPROTO_ICMPV6);
+
+ /* Generate checksum */
+
+ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
+ checksum = inet_checksum(icmp, ntohl(pseudo.length), checksum);
+
+ icmp->icmp6_cksum = checksum;
+
+ packet->len = 14 + sizeof(*hdr) + ntohl(pseudo.length);
+
+ write_packet(packet);
+}
+
+static node_t *route_ipv6(vpn_packet_t *packet)
{
subnet_t *subnet;
subnet = lookup_subnet_ipv6((ipv6_t *) & packet->data[38]);
if(!subnet) {
- if(debug_lvl >= DEBUG_TRAFFIC) {
- syslog(LOG_WARNING, _("Cannot route packet: unknown IPv6 destination address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"),
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: unknown IPv6 destination address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"),
ntohs(*(uint16_t *) & packet->data[38]),
ntohs(*(uint16_t *) & packet->data[40]),
ntohs(*(uint16_t *) & packet->data[42]),
ntohs(*(uint16_t *) & packet->data[48]),
ntohs(*(uint16_t *) & packet->data[50]),
ntohs(*(uint16_t *) & packet->data[52]));
- }
+ route_ipv6_unreachable(packet, ICMP6_DST_UNREACH_ADDR);
return NULL;
}
+ if(!subnet->owner->status.reachable)
+ route_ipv6_unreachable(packet, ICMP6_DST_UNREACH_NOROUTE);
+
return subnet->owner;
}
-uint16_t inet_checksum(uint16_t * data, int len, uint16_t prevsum)
-{
- uint32_t checksum = prevsum ^ 0xFFFF;
-
- while(len--)
- checksum += ntohs(*data++);
+/* RFC 2461 */
- while(checksum >> 16)
- checksum = (checksum & 0xFFFF) + (checksum >> 16);
-
- return checksum ^ 0xFFFF;
-}
-
-void route_neighborsol(vpn_packet_t * packet)
+static void route_neighborsol(vpn_packet_t *packet)
{
struct ip6_hdr *hdr;
struct nd_neighbor_solicit *ns;
struct in6_addr ip6_src; /* source address */
struct in6_addr ip6_dst; /* destination address */
uint32_t length;
- uint8_t junk[4];
+ uint32_t next;
} pseudo;
cp();
- hdr = (struct ip6_hdr *) (packet->data + 14);
- ns = (struct nd_neighbor_solicit *) (packet->data + 14 + sizeof(*hdr));
- opt = (struct nd_opt_hdr *) (packet->data + 14 + sizeof(*hdr) + sizeof(*ns));
+ hdr = (struct ip6_hdr *)(packet->data + 14);
+ ns = (struct nd_neighbor_solicit *)(packet->data + 14 + sizeof(*hdr));
+ opt = (struct nd_opt_hdr *)(packet->data + 14 + sizeof(*hdr) + sizeof(*ns));
/* First, snatch the source address from the neighbor solicitation packet */
- memcpy(mymac.net.mac.address.x, packet->data + 6, 6);
+ if(overwrite_mac)
+ memcpy(mymac.x, packet->data + 6, 6);
/* Check if this is a valid neighbor solicitation request */
if(ns->nd_ns_hdr.icmp6_type != ND_NEIGHBOR_SOLICIT ||
opt->nd_opt_type != ND_OPT_SOURCE_LINKADDR) {
- if(debug_lvl > DEBUG_TRAFFIC) {
- syslog(LOG_WARNING, _("Cannot route packet: received unknown type neighbor solicitation request"));
- }
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type neighbor solicitation request"));
return;
}
memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6);
- pseudo.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0;
- pseudo.junk[3] = IPPROTO_ICMPV6;
+ pseudo.next = htonl(IPPROTO_ICMPV6);
/* Generate checksum */
- checksum = inet_checksum((uint16_t *) & pseudo, sizeof(pseudo) / 2, ~0);
- checksum = inet_checksum((uint16_t *) ns, sizeof(*ns) / 2 + 4, checksum);
+ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
+ checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum);
if(checksum) {
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_WARNING, _("Cannot route packet: checksum error for neighbor solicitation request"));
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: checksum error for neighbor solicitation request"));
return;
}
subnet = lookup_subnet_ipv6((ipv6_t *) & ns->nd_ns_target);
if(!subnet) {
- if(debug_lvl >= DEBUG_TRAFFIC) {
- syslog(LOG_WARNING, _("Cannot route packet: neighbor solicitation request for unknown address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"),
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: neighbor solicitation request for unknown address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"),
ntohs(((uint16_t *) & ns->nd_ns_target)[0]),
ntohs(((uint16_t *) & ns->nd_ns_target)[1]),
ntohs(((uint16_t *) & ns->nd_ns_target)[2]),
ntohs(((uint16_t *) & ns->nd_ns_target)[5]),
ntohs(((uint16_t *) & ns->nd_ns_target)[6]),
ntohs(((uint16_t *) & ns->nd_ns_target)[7]));
- }
return;
}
memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6);
- pseudo.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0;
- pseudo.junk[3] = IPPROTO_ICMPV6;
+ pseudo.next = htonl(IPPROTO_ICMPV6);
/* Generate checksum */
- checksum = inet_checksum((uint16_t *) & pseudo, sizeof(pseudo) / 2, ~0);
- checksum = inet_checksum((uint16_t *) ns, sizeof(*ns) / 2 + 4, checksum);
+ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
+ checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum);
- ns->nd_ns_hdr.icmp6_cksum = htons(checksum);
+ ns->nd_ns_hdr.icmp6_cksum = checksum;
write_packet(packet);
}
-void route_arp(vpn_packet_t * packet)
+/* RFC 826 */
+
+static void route_arp(vpn_packet_t *packet)
{
struct ether_arp *arp;
subnet_t *subnet;
/* First, snatch the source address from the ARP packet */
- memcpy(mymac.net.mac.address.x, packet->data + 6, 6);
+ if(overwrite_mac)
+ memcpy(mymac.x, packet->data + 6, 6);
/* This routine generates replies to ARP requests.
You don't need to set NOARP flag on the interface anymore (which is broken on FreeBSD).
Most of the code here is taken from choparp.c by Takamichi Tateoka (tree@mma.club.uec.ac.jp)
*/
- arp = (struct ether_arp *) (packet->data + 14);
+ arp = (struct ether_arp *)(packet->data + 14);
/* Check if this is a valid ARP request */
if(ntohs(arp->arp_hrd) != ARPHRD_ETHER || ntohs(arp->arp_pro) != ETHERTYPE_IP ||
arp->arp_hln != ETHER_ADDR_LEN || arp->arp_pln != 4 || ntohs(arp->arp_op) != ARPOP_REQUEST) {
- if(debug_lvl > DEBUG_TRAFFIC) {
- syslog(LOG_WARNING, _("Cannot route packet: received unknown type ARP request"));
- }
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type ARP request"));
return;
}
subnet = lookup_subnet_ipv4((ipv4_t *) arp->arp_tpa);
if(!subnet) {
- if(debug_lvl >= DEBUG_TRAFFIC) {
- syslog(LOG_WARNING, _("Cannot route packet: ARP request for unknown address %d.%d.%d.%d"),
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: ARP request for unknown address %d.%d.%d.%d"),
arp->arp_tpa[0], arp->arp_tpa[1], arp->arp_tpa[2],
arp->arp_tpa[3]);
- }
-
return;
}
write_packet(packet);
}
-void route_outgoing(vpn_packet_t * packet)
+void route_outgoing(vpn_packet_t *packet)
{
uint16_t type;
node_t *n = NULL;
switch (routing_mode) {
case RMODE_ROUTER:
- type = ntohs(*((uint16_t *) (&packet->data[12])));
+ type = ntohs(*((uint16_t *)(&packet->data[12])));
switch (type) {
case 0x0800:
n = route_ipv4(packet);
return;
default:
- if(debug_lvl >= DEBUG_TRAFFIC)
- syslog(LOG_WARNING, _("Cannot route packet: unknown type %hx"), type);
+ ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: unknown type %hx"), type);
return;
}
if(n)
}
}
-void route_incoming(node_t * source, vpn_packet_t * packet)
+void route_incoming(node_t *source, vpn_packet_t *packet)
{
switch (routing_mode) {
case RMODE_ROUTER:
node_t *n = NULL;
uint16_t type;
- type = ntohs(*((uint16_t *) (&packet->data[12])));
+ type = ntohs(*((uint16_t *)(&packet->data[12])));
switch (type) {
case 0x0800:
n = route_ipv4(packet);
if(n) {
if(n == myself) {
- memcpy(packet->data, mymac.net.mac.address.x, 6);
+ if(overwrite_mac)
+ memcpy(packet->data, mymac.x, 6);
write_packet(packet);
} else
send_packet(n, packet);
{
subnet_t *subnet;
- subnet = lookup_subnet_mac((mac_t *) (&packet->data[0]));
+ subnet = lookup_subnet_mac((mac_t *)(&packet->data[0]));
if(subnet) {
if(subnet->owner == myself)
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