Better length checks.
[tinc] / src / route.c
index 571b1ba..e9e07f6 100644 (file)
@@ -1,7 +1,7 @@
 /*
     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 1.1.2.50 2003/06/11 19:28:35 guus Exp $
+    $Id: route.c,v 1.1.2.66 2003/10/01 09:14:01 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
-#include <netinet/ip.h>
+#ifdef HAVE_NETINET_IP_ICMP_H
 #include <netinet/ip_icmp.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 "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"
 
-#include "system.h"
-
-#ifndef ETHER_ADDR_LEN
-#define ETHER_ADDR_LEN 6
-#endif
-
-int routing_mode = RMODE_ROUTER;
-int priorityinheritance = 0;
+rmode_t routing_mode = RMODE_ROUTER;
+bool priorityinheritance = false;
 int macexpire = 600;
-int overwrite_mac = 0;
-mac_t mymac = {0xFE, 0xFD, 0, 0, 0, 0};
+bool overwrite_mac = false;
+mac_t mymac = {{0xFE, 0xFD, 0, 0, 0, 0}};
 
 /* RFC 1071 */
 
-uint16_t inet_checksum(void *data, int len, uint16_t prevsum)
+static uint16_t inet_checksum(void *data, int len, uint16_t prevsum)
 {
        uint16_t *p = data;
        uint32_t checksum = prevsum ^ 0xFFFF;
@@ -91,17 +78,17 @@ uint16_t inet_checksum(void *data, int len, uint16_t prevsum)
        return ~checksum;
 }
 
-int ratelimit(void) {
+static bool ratelimit(void) {
        static time_t lasttime = 0;
        
        if(lasttime == now)
-               return 1;
+               return true;
 
        lasttime = now;
-       return 0;
+       return false;
 }
        
-void learn_mac(mac_t *address)
+static void learn_mac(mac_t *address)
 {
        subnet_t *subnet;
        avl_node_t *node;
@@ -114,8 +101,7 @@ void learn_mac(mac_t *address)
        /* 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]);
 
@@ -127,7 +113,7 @@ void learn_mac(mac_t *address)
                /* And tell all other tinc daemons it's our MAC */
 
                for(node = connection_tree->head; node; node = node->next) {
-                       c = (connection_t *) node->data;
+                       c = node->data;
                        if(c->status.active)
                                send_add_subnet(c, subnet);
                }
@@ -146,16 +132,15 @@ void age_mac(void)
 
        for(node = myself->subnet_tree->head; node; node = next) {
                next = node->next;
-               s = (subnet_t *) node->data;
+               s = 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]);
 
                        for(node2 = connection_tree->head; node2; node2 = node2->next) {
-                               c = (connection_t *) node2->data;
+                               c = node2->data;
                                if(c->status.active)
                                        send_del_subnet(c, s);
                        }
@@ -165,7 +150,7 @@ void age_mac(void)
        }
 }
 
-node_t *route_mac(vpn_packet_t *packet)
+static node_t *route_mac(vpn_packet_t *packet)
 {
        subnet_t *subnet;
 
@@ -187,7 +172,7 @@ node_t *route_mac(vpn_packet_t *packet)
 
 /* RFC 792 */
 
-void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code)
+static void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code)
 {
        struct ip *hdr;
        struct icmp *icmp;
@@ -210,8 +195,8 @@ void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code)
        memcpy(&ip_dst, &hdr->ip_dst, 4);
        oldlen = packet->len - 14;
        
-       if(oldlen >= IP_MSS - sizeof(*hdr) - sizeof(struct icmphdr))
-               oldlen = IP_MSS - sizeof(*hdr) - sizeof(struct icmphdr);
+       if(oldlen >= IP_MSS - sizeof(*hdr) - sizeof(*icmp))
+               oldlen = IP_MSS - sizeof(*hdr) - sizeof(*icmp);
        
        /* Copy first part of original contents to ICMP message */
        
@@ -246,7 +231,7 @@ void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code)
        write_packet(packet);
 }
 
-node_t *route_ipv4(vpn_packet_t *packet)
+static node_t *route_ipv4(vpn_packet_t *packet)
 {
        subnet_t *subnet;
 
@@ -255,14 +240,12 @@ node_t *route_ipv4(vpn_packet_t *packet)
        if(priorityinheritance)
                packet->priority = packet->data[15];
 
-       subnet = lookup_subnet_ipv4((ipv4_t *) & packet->data[30]);
+       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;
@@ -276,7 +259,7 @@ node_t *route_ipv4(vpn_packet_t *packet)
 
 /* RFC 2463 */
 
-void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code)
+static void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code)
 {
        struct ip6_hdr *hdr;
        struct icmp6_hdr *icmp;
@@ -342,26 +325,24 @@ void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code)
        write_packet(packet);
 }
 
-node_t *route_ipv6(vpn_packet_t *packet)
+static node_t *route_ipv6(vpn_packet_t *packet)
 {
        subnet_t *subnet;
 
        cp();
 
-       subnet = lookup_subnet_ipv6((ipv6_t *) & packet->data[38]);
+       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"),
-                                  ntohs(*(uint16_t *) & packet->data[38]),
-                                  ntohs(*(uint16_t *) & packet->data[40]),
-                                  ntohs(*(uint16_t *) & packet->data[42]),
-                                  ntohs(*(uint16_t *) & packet->data[44]),
-                                  ntohs(*(uint16_t *) & packet->data[46]),
-                                  ntohs(*(uint16_t *) & packet->data[48]),
-                                  ntohs(*(uint16_t *) & packet->data[50]),
-                                  ntohs(*(uint16_t *) & packet->data[52]));
-               }
+               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[44]),
+                                  ntohs(*(uint16_t *) &packet->data[46]),
+                                  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;
@@ -369,13 +350,13 @@ node_t *route_ipv6(vpn_packet_t *packet)
 
        if(!subnet->owner->status.reachable)
                route_ipv6_unreachable(packet, ICMP6_DST_UNREACH_NOROUTE);
-
+       
        return subnet->owner;
 }
 
 /* RFC 2461 */
 
-void route_neighborsol(vpn_packet_t *packet)
+static void route_neighborsol(vpn_packet_t *packet)
 {
        struct ip6_hdr *hdr;
        struct nd_neighbor_solicit *ns;
@@ -405,9 +386,7 @@ void route_neighborsol(vpn_packet_t *packet)
 
        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;
        }
 
@@ -424,27 +403,24 @@ void route_neighborsol(vpn_packet_t *packet)
        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;
        }
 
        /* Check if the IPv6 address exists on the VPN */
 
-       subnet = lookup_subnet_ipv6((ipv6_t *) & ns->nd_ns_target);
+       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"),
-                                  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)[3]),
-                                  ntohs(((uint16_t *) & ns->nd_ns_target)[4]),
-                                  ntohs(((uint16_t *) & ns->nd_ns_target)[5]),
-                                  ntohs(((uint16_t *) & ns->nd_ns_target)[6]),
-                                  ntohs(((uint16_t *) & ns->nd_ns_target)[7]));
-               }
+               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)[3]),
+                                  ntohs(((uint16_t *) &ns->nd_ns_target)[4]),
+                                  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;
        }
@@ -491,7 +467,7 @@ void route_neighborsol(vpn_packet_t *packet)
 
 /* RFC 826 */
 
-void route_arp(vpn_packet_t *packet)
+static void route_arp(vpn_packet_t *packet)
 {
        struct ether_arp *arp;
        subnet_t *subnet;
@@ -515,9 +491,7 @@ void route_arp(vpn_packet_t *packet)
 
        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;
        }
 
@@ -526,12 +500,9 @@ void route_arp(vpn_packet_t *packet)
        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;
        }
 
@@ -561,6 +532,11 @@ void route_outgoing(vpn_packet_t *packet)
 
        cp();
 
+       if(packet->len < 14) {
+               ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
+               return;
+       }
+
        /* FIXME: multicast? */
 
        switch (routing_mode) {
@@ -568,11 +544,21 @@ void route_outgoing(vpn_packet_t *packet)
                        type = ntohs(*((uint16_t *)(&packet->data[12])));
                        switch (type) {
                                case 0x0800:
+                                       if(packet->len < 34) {
+                                               ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
+                                               return;
+                                       }
+
                                        n = route_ipv4(packet);
                                        break;
 
                                case 0x86DD:
-                                       if(packet->data[20] == IPPROTO_ICMPV6 && packet->data[54] == ND_NEIGHBOR_SOLICIT) {
+                                       if(packet->len < 54) {
+                                               ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
+                                               return;
+                                       }
+
+                                       if(packet->data[20] == IPPROTO_ICMPV6 && packet->len >= 62 && packet->data[54] == ND_NEIGHBOR_SOLICIT) {
                                                route_neighborsol(packet);
                                                return;
                                        }
@@ -580,12 +566,16 @@ void route_outgoing(vpn_packet_t *packet)
                                        break;
 
                                case 0x0806:
+                                       if(packet->len < 42) {
+                                               ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
+                                               return;
+                                       }
+
                                        route_arp(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)
@@ -608,6 +598,12 @@ void route_outgoing(vpn_packet_t *packet)
 
 void route_incoming(node_t *source, vpn_packet_t *packet)
 {
+       if(packet->len < 14) {
+               ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got too short packet from %s (%s)"),
+                                       source->name, source->hostname);
+               return;
+       }
+
        switch (routing_mode) {
                case RMODE_ROUTER:
                        {
@@ -617,10 +613,20 @@ void route_incoming(node_t *source, vpn_packet_t *packet)
                                type = ntohs(*((uint16_t *)(&packet->data[12])));
                                switch (type) {
                                        case 0x0800:
+                                               if(packet->len < 34) {
+                                                       ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
+                                                       return;
+                                               }
+
                                                n = route_ipv4(packet);
                                                break;
 
                                        case 0x86DD:
+                                               if(packet->len < 54) {
+                                                       ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet"));
+                                                       return;
+                                               }
+
                                                n = route_ipv6(packet);
                                                break;