X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Froute.c;h=89271ba876168cdeb8a73e918386300449015da9;hp=ff84ee985864ea5a25c88448d7cc788d947c49b2;hb=30c0381d71d333a99f6c83ff9d03ef4a0857f423;hpb=6f9f6779e6bd1dd7bb795b42dad550863a386ca8 diff --git a/src/route.c b/src/route.c index ff84ee98..89271ba8 100644 --- a/src/route.c +++ b/src/route.c @@ -17,7 +17,7 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: route.c,v 1.1.2.46 2002/09/09 22:33:16 guus Exp $ + $Id: route.c,v 1.1.2.56 2003/07/07 11:11:33 guus Exp $ */ #include "config.h" @@ -36,12 +36,15 @@ #ifdef HAVE_NETINET_IN_SYSTM_H #include #endif +#include +#include +#ifdef HAVE_NETINET_IP6_H #include #include +#endif #include #include #include -#include #include #ifdef HAVE_INTTYPES_H #include @@ -55,19 +58,66 @@ #include "route.h" #include "protocol.h" #include "device.h" +#include "logger.h" #include "system.h" +/* Missing definitions */ + #ifndef ETHER_ADDR_LEN #define ETHER_ADDR_LEN 6 #endif +#ifndef ICMP_DEST_UNREACH +#define ICMP_DEST_UNREACH 3 +#endif + +#ifndef ICMP_NET_UNKNOWN +#define ICMP_NET_UNKNOWN 6 +#endif + +#ifndef ICMP_NET_UNREACH +#define ICMP_NET_UNREACH 0 +#endif + int routing_mode = RMODE_ROUTER; int priorityinheritance = 0; int macexpire = 600; -subnet_t mymac; +int overwrite_mac = 0; +static mac_t mymac = {{0xFE, 0xFD, 0, 0, 0, 0}}; + +/* RFC 1071 */ -void learn_mac(mac_t *address) +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; @@ -80,8 +130,7 @@ 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"), + logger(DEBUG_TRAFFIC, 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]); @@ -114,8 +163,7 @@ void age_mac(void) 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"), + logger(DEBUG_TRAFFIC, 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]); @@ -131,7 +179,7 @@ void age_mac(void) } } -node_t *route_mac(vpn_packet_t *packet) +static node_t *route_mac(vpn_packet_t *packet) { subnet_t *subnet; @@ -151,7 +199,68 @@ node_t *route_mac(vpn_packet_t *packet) 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; @@ -163,19 +272,89 @@ node_t *route_ipv4(vpn_packet_t *packet) 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"), + logger(DEBUG_TRAFFIC, 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; @@ -184,8 +363,7 @@ node_t *route_ipv6(vpn_packet_t *packet) 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"), + logger(DEBUG_TRAFFIC, 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]), @@ -194,28 +372,20 @@ node_t *route_ipv6(vpn_packet_t *packet) 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++); - - while(checksum >> 16) - checksum = (checksum & 0xFFFF) + (checksum >> 16); - - return checksum ^ 0xFFFF; -} +/* 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; @@ -227,7 +397,7 @@ void route_neighborsol(vpn_packet_t *packet) 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(); @@ -238,15 +408,14 @@ void route_neighborsol(vpn_packet_t *packet) /* 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")); - } + logger(DEBUG_TRAFFIC, LOG_WARNING, _("Cannot route packet: received unknown type neighbor solicitation request")); return; } @@ -255,17 +424,15 @@ void route_neighborsol(vpn_packet_t *packet) 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")); + logger(DEBUG_TRAFFIC, LOG_WARNING, _("Cannot route packet: checksum error for neighbor solicitation request")); return; } @@ -274,8 +441,7 @@ void route_neighborsol(vpn_packet_t *packet) 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"), + logger(DEBUG_TRAFFIC, 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]), @@ -284,7 +450,6 @@ void route_neighborsol(vpn_packet_t *packet) 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; } @@ -317,20 +482,21 @@ void route_neighborsol(vpn_packet_t *packet) 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; @@ -340,7 +506,8 @@ void route_arp(vpn_packet_t *packet) /* 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). @@ -353,9 +520,7 @@ 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")); - } + logger(DEBUG_TRAFFIC, LOG_WARNING, _("Cannot route packet: received unknown type ARP request")); return; } @@ -364,12 +529,9 @@ 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"), + logger(DEBUG_TRAFFIC, 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; } @@ -422,8 +584,7 @@ void route_outgoing(vpn_packet_t *packet) return; default: - if(debug_lvl >= DEBUG_TRAFFIC) - syslog(LOG_WARNING, _("Cannot route packet: unknown type %hx"), type); + logger(DEBUG_TRAFFIC, LOG_WARNING, _("Cannot route packet: unknown type %hx"), type); return; } if(n) @@ -469,7 +630,8 @@ void route_incoming(node_t *source, vpn_packet_t *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);