X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Froute.c;h=bacfa626eda5ad8dcbfc1b860bde35d3ba255c01;hp=0123107e4acabc444efbc8767d07410a26939396;hb=4a5c12ec97fa1e82aae2d327fdc648e5203eb478;hpb=134dc8995b296b0bd8b346617c705204b0f3125c diff --git a/src/route.c b/src/route.c index 0123107e..bacfa626 100644 --- a/src/route.c +++ b/src/route.c @@ -1,7 +1,8 @@ /* route.c -- routing Copyright (C) 2000-2005 Ivo Timmermans, - 2000-2006 Guus Sliepen + 2000-2014 Guus Sliepen + 2015 Vittorio Gambaletta 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 @@ -13,11 +14,9 @@ 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. - - $Id$ + 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., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "system.h" @@ -35,6 +34,10 @@ #include "utils.h" rmode_t routing_mode = RMODE_ROUTER; +fmode_t forwarding_mode = FMODE_INTERNAL; +bmode_t broadcast_mode = BMODE_MST; +bool decrement_ttl = false; +bool directonly = false; bool priorityinheritance = false; int macexpire = 600; bool overwrite_mac = false; @@ -51,10 +54,13 @@ static const size_t icmp6_size = sizeof(struct icmp6_hdr); static const size_t ns_size = sizeof(struct nd_neighbor_solicit); static const size_t opt_size = sizeof(struct nd_opt_hdr); +#ifndef MAX +#define MAX(a, b) ((a) > (b) ? (a) : (b)) +#endif + /* RFC 1071 */ -static 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; @@ -77,127 +83,35 @@ static bool ratelimit(int frequency) { static int count = 0; if(lasttime == now) { - if(++count > frequency) + if(count >= frequency) return true; } else { lasttime = now; count = 0; } + count++; return false; } static bool checklength(node_t *source, vpn_packet_t *packet, length_t length) { if(packet->len < length) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got too short packet from %s (%s)"), source->name, source->hostname); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Got too short packet from %s (%s)", source->name, source->hostname); return false; } else return true; } - -static void learn_mac(mac_t *address) -{ - subnet_t *subnet; - avl_node_t *node; - connection_t *c; - - cp(); - - subnet = lookup_subnet_mac(address); - - /* If we don't know this MAC address yet, store it */ - - if(!subnet) { - 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]); - - subnet = new_subnet(); - subnet->type = SUBNET_MAC; - subnet->expires = now + macexpire; - subnet->net.mac.address = *address; - subnet_add(myself, subnet); - - /* And tell all other tinc daemons it's our MAC */ - - for(node = connection_tree->head; node; node = node->next) { - c = node->data; - if(c->status.active) - send_add_subnet(c, subnet); - } - } - if(subnet->expires) - subnet->expires = now + macexpire; -} - -void age_subnets(void) -{ - subnet_t *s; - connection_t *c; - avl_node_t *node, *next, *node2; - - cp(); - - for(node = myself->subnet_tree->head; node; node = next) { - next = node->next; - s = node->data; - if(s->expires && s->expires < now) { - ifdebug(TRAFFIC) { - char netstr[MAXNETSTR]; - if(net2str(netstr, sizeof netstr, s)) - logger(LOG_INFO, _("Subnet %s expired"), netstr); - } - - for(node2 = connection_tree->head; node2; node2 = node2->next) { - c = node2->data; - if(c->status.active) - send_del_subnet(c, s); - } - - subnet_del(myself, s); - } - } -} - -static void route_mac(node_t *source, vpn_packet_t *packet) -{ - subnet_t *subnet; - mac_t dest; - - cp(); - - - /* Learn source address */ - - if(source == myself) { - mac_t src; - memcpy(&src, &packet->data[6], sizeof src); - learn_mac(&src); - } - - /* Lookup destination address */ - - memcpy(&dest, &packet->data[0], sizeof dest); - subnet = lookup_subnet_mac(&dest); - - if(!subnet) { - broadcast_packet(source, packet); - return; - } - - if(subnet->owner == source) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Packet looping back to %s (%s)!"), source->name, source->hostname); - return; - } - - send_packet(subnet->owner, packet); +static void swap_mac_addresses(vpn_packet_t *packet) { + mac_t tmp; + memcpy(&tmp, &packet->data[0], sizeof tmp); + memcpy(&packet->data[0], &packet->data[6], sizeof tmp); + memcpy(&packet->data[6], &tmp, sizeof tmp); } /* RFC 792 */ -static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t type, uint8_t code) -{ +static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) { struct ip ip = {0}; struct icmp icmp = {0}; @@ -208,7 +122,9 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t if(ratelimit(3)) return; - cp(); + /* Swap Ethernet source and destination addresses */ + + swap_mac_addresses(packet); /* Copy headers from packet into properly aligned structs on the stack */ @@ -219,6 +135,27 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t ip_src = ip.ip_src; ip_dst = ip.ip_dst; + /* Try to reply with an IP address assigned to the local machine */ + + if (type == ICMP_TIME_EXCEEDED && code == ICMP_EXC_TTL) { + int sockfd = socket(AF_INET, SOCK_DGRAM, 0); + if (sockfd != -1) { + struct sockaddr_in addr; + memset(&addr, 0, sizeof(addr)); + addr.sin_family = AF_INET; + addr.sin_addr = ip.ip_src; + if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) { + memset(&addr, 0, sizeof(addr)); + addr.sin_family = AF_INET; + socklen_t addrlen = sizeof(addr); + if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) { + ip_dst = addr.sin_addr; + } + } + close(sockfd); + } + } + oldlen = packet->len - ether_size; if(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) @@ -266,17 +203,319 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t send_packet(source, packet); } +/* RFC 2463 */ + +static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) { + struct ip6_hdr ip6; + struct icmp6_hdr icmp6 = {0}; + 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(3)) + return; + + /* Swap Ethernet source and destination addresses */ + + swap_mac_addresses(packet); + + /* Copy headers from packet to structs on the stack */ + + memcpy(&ip6, packet->data + ether_size, ip6_size); + + /* Remember original source and destination */ + + pseudo.ip6_src = ip6.ip6_dst; + pseudo.ip6_dst = ip6.ip6_src; + + /* Try to reply with an IP address assigned to the local machine */ + + if (type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT) { + int sockfd = socket(AF_INET6, SOCK_DGRAM, 0); + if (sockfd != -1) { + struct sockaddr_in6 addr; + memset(&addr, 0, sizeof(addr)); + addr.sin6_family = AF_INET6; + addr.sin6_addr = ip6.ip6_src; + if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) { + memset(&addr, 0, sizeof(addr)); + addr.sin6_family = AF_INET6; + socklen_t addrlen = sizeof(addr); + if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) { + pseudo.ip6_src = addr.sin6_addr; + } + } + close(sockfd); + } + } + + pseudo.length = packet->len - ether_size; + + if(type == ICMP6_PACKET_TOO_BIG) + icmp6.icmp6_mtu = htonl(pseudo.length); + + if(pseudo.length >= IP_MSS - ip6_size - icmp6_size) + pseudo.length = IP_MSS - ip6_size - icmp6_size; + + /* Copy first part of original contents to ICMP message */ + + memmove(packet->data + ether_size + ip6_size + icmp6_size, packet->data + ether_size, pseudo.length); + + /* Fill in IPv6 header */ + + ip6.ip6_flow = htonl(0x60000000UL); + ip6.ip6_plen = htons(icmp6_size + pseudo.length); + ip6.ip6_nxt = IPPROTO_ICMPV6; + ip6.ip6_hlim = 255; + ip6.ip6_src = pseudo.ip6_src; + ip6.ip6_dst = pseudo.ip6_dst; + + /* Fill in ICMP header */ + + icmp6.icmp6_type = type; + icmp6.icmp6_code = code; + icmp6.icmp6_cksum = 0; + + /* Create pseudo header */ + + pseudo.length = htonl(icmp6_size + pseudo.length); + pseudo.next = htonl(IPPROTO_ICMPV6); + + /* Generate checksum */ + + checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); + checksum = inet_checksum(&icmp6, icmp6_size, checksum); + checksum = inet_checksum(packet->data + ether_size + ip6_size + icmp6_size, ntohl(pseudo.length) - icmp6_size, checksum); + + icmp6.icmp6_cksum = checksum; + + /* Copy structs on stack back to packet */ + + memcpy(packet->data + ether_size, &ip6, ip6_size); + memcpy(packet->data + ether_size + ip6_size, &icmp6, icmp6_size); + + packet->len = ether_size + ip6_size + ntohl(pseudo.length); + + send_packet(source, packet); +} + +static bool do_decrement_ttl(node_t *source, vpn_packet_t *packet) { + uint16_t type = packet->data[12] << 8 | packet->data[13]; + length_t ethlen = ether_size; + + if(type == ETH_P_8021Q) { + type = packet->data[16] << 8 | packet->data[17]; + ethlen += 4; + } + + switch (type) { + case ETH_P_IP: + if(!checklength(source, packet, ethlen + ip_size)) + return false; + + if(packet->data[ethlen + 8] <= 1) { + if(packet->data[ethlen + 11] != IPPROTO_ICMP || packet->data[ethlen + 32] != ICMP_TIME_EXCEEDED) + route_ipv4_unreachable(source, packet, ethlen, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL); + return false; + } + + uint16_t old = packet->data[ethlen + 8] << 8 | packet->data[ethlen + 9]; + packet->data[ethlen + 8]--; + uint16_t new = packet->data[ethlen + 8] << 8 | packet->data[ethlen + 9]; + + uint32_t checksum = packet->data[ethlen + 10] << 8 | packet->data[ethlen + 11]; + checksum += old + (~new & 0xFFFF); + while(checksum >> 16) + checksum = (checksum & 0xFFFF) + (checksum >> 16); + packet->data[ethlen + 10] = checksum >> 8; + packet->data[ethlen + 11] = checksum & 0xff; + + return true; + + case ETH_P_IPV6: + if(!checklength(source, packet, ethlen + ip6_size)) + return false; + + if(packet->data[ethlen + 7] <= 1) { + if(packet->data[ethlen + 6] != IPPROTO_ICMPV6 || packet->data[ethlen + 40] != ICMP6_TIME_EXCEEDED) + route_ipv6_unreachable(source, packet, ethlen, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT); + return false; + } + + packet->data[ethlen + 7]--; + + return true; + + default: + return true; + } +} + +static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *packet) { + if(!source || !via || !(via->options & OPTION_CLAMP_MSS)) + return; + + uint16_t mtu = source->mtu; + if(via != myself && via->mtu < mtu) + mtu = via->mtu; + + /* Find TCP header */ + int start = ether_size; + uint16_t type = packet->data[12] << 8 | packet->data[13]; + + if(type == ETH_P_8021Q) { + start += 4; + type = packet->data[16] << 8 | packet->data[17]; + } + + if(type == ETH_P_IP && packet->data[start + 9] == 6) + start += (packet->data[start] & 0xf) * 4; + else if(type == ETH_P_IPV6 && packet->data[start + 6] == 6) + start += 40; + else + return; + + if(packet->len <= start + 20) + return; + + /* Use data offset field to calculate length of options field */ + int len = ((packet->data[start + 12] >> 4) - 5) * 4; + + if(packet->len < start + 20 + len) + return; + + /* Search for MSS option header */ + for(int i = 0; i < len;) { + if(packet->data[start + 20 + i] == 0) + break; + + if(packet->data[start + 20 + i] == 1) { + i++; + continue; + } + + if(i > len - 2 || i > len - packet->data[start + 21 + i]) + break; + + if(packet->data[start + 20 + i] != 2) { + if(packet->data[start + 21 + i] < 2) + break; + i += packet->data[start + 21 + i]; + continue; + } + + if(packet->data[start + 21] != 4) + break; + + /* Found it */ + uint16_t oldmss = packet->data[start + 22 + i] << 8 | packet->data[start + 23 + i]; + uint16_t newmss = mtu - start - 20; + uint32_t csum = packet->data[start + 16] << 8 | packet->data[start + 17]; + + if(oldmss <= newmss) + break; + + ifdebug(TRAFFIC) logger(LOG_INFO, "Clamping MSS of packet from %s to %s to %d", source->name, via->name, newmss); + + /* Update the MSS value and the checksum */ + packet->data[start + 22 + i] = newmss >> 8; + packet->data[start + 23 + i] = newmss & 0xff; + csum ^= 0xffff; + csum += oldmss ^ 0xffff; + csum += newmss; + csum = (csum & 0xffff) + (csum >> 16); + csum += csum >> 16; + csum ^= 0xffff; + packet->data[start + 16] = csum >> 8; + packet->data[start + 17] = csum; + break; + } +} + +static void learn_mac(mac_t *address) { + subnet_t *subnet; + avl_node_t *node; + connection_t *c; + + subnet = lookup_subnet_mac(myself, address); + + /* If we don't know this MAC address yet, store it */ + + if(!subnet) { + ifdebug(TRAFFIC) logger(LOG_INFO, "Learned new MAC address %x:%x:%x:%x:%x:%x", + address->x[0], address->x[1], address->x[2], address->x[3], + address->x[4], address->x[5]); + + subnet = new_subnet(); + subnet->type = SUBNET_MAC; + subnet->expires = now + macexpire; + subnet->net.mac.address = *address; + subnet->weight = 10; + subnet_add(myself, subnet); + subnet_update(myself, subnet, true); + + /* And tell all other tinc daemons it's our MAC */ + + for(node = connection_tree->head; node; node = node->next) { + c = node->data; + if(c->status.active) + send_add_subnet(c, subnet); + } + } + + if(subnet->expires) + subnet->expires = now + macexpire; +} + +void age_subnets(void) { + subnet_t *s; + connection_t *c; + avl_node_t *node, *next, *node2; + + for(node = myself->subnet_tree->head; node; node = next) { + next = node->next; + s = node->data; + if(s->expires && s->expires <= now) { + ifdebug(TRAFFIC) { + char netstr[MAXNETSTR]; + if(net2str(netstr, sizeof netstr, s)) + logger(LOG_INFO, "Subnet %s expired", netstr); + } + + for(node2 = connection_tree->head; node2; node2 = node2->next) { + c = node2->data; + if(c->status.active) + send_del_subnet(c, s); + } + + subnet_update(myself, s, false); + subnet_del(myself, s); + } + } +} + +static void route_broadcast(node_t *source, vpn_packet_t *packet) { + if(decrement_ttl && source != myself) + if(!do_decrement_ttl(source, packet)) + return; + + broadcast_packet(source, packet); +} + /* RFC 791 */ -static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet) { +static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet, length_t ether_size) { struct ip ip; vpn_packet_t fragment; int len, maxlen, todo; uint8_t *offset; uint16_t ip_off, origf; - cp(); - memcpy(&ip, packet->data + ether_size, ip_size); fragment.priority = packet->priority; @@ -286,11 +525,11 @@ static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet) { todo = ntohs(ip.ip_len) - ip_size; if(ether_size + ip_size + todo != packet->len) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Length of packet (%d) doesn't match length in IPv4 header (%zd)"), packet->len, ether_size + ip_size + todo); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Length of packet (%d) doesn't match length in IPv4 header (%d)", packet->len, (int)(ether_size + ip_size + todo)); return; } - ifdebug(TRAFFIC) logger(LOG_INFO, _("Fragmenting packet of %d bytes to %s (%s)"), packet->len, dest->name, dest->hostname); + ifdebug(TRAFFIC) logger(LOG_INFO, "Fragmenting packet of %d bytes to %s (%s)", packet->len, dest->name, dest->hostname); offset = packet->data + ether_size + ip_size; maxlen = (dest->mtu - ether_size - ip_size) & ~0x7; @@ -318,159 +557,95 @@ static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet) { } } -static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) -{ +static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) { subnet_t *subnet; node_t *via; ipv4_t dest; - cp(); - memcpy(&dest, &packet->data[30], sizeof dest); subnet = lookup_subnet_ipv4(&dest); if(!subnet) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet from %s (%s): unknown IPv4 destination address %d.%d.%d.%d"), + ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet from %s (%s): unknown IPv4 destination address %d.%d.%d.%d", source->name, source->hostname, dest.x[0], dest.x[1], dest.x[2], dest.x[3]); - route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNKNOWN); + route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_UNKNOWN); return; } if(subnet->owner == source) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Packet looping back to %s (%s)!"), source->name, source->hostname); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname); return; } if(!subnet->owner->status.reachable) - route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNREACH); + return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_UNREACH); + + if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) + return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO); + + if(decrement_ttl && source != myself && subnet->owner != myself) + if(!do_decrement_ttl(source, packet)) + return; if(priorityinheritance) packet->priority = packet->data[15]; via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via; + + if(via == source) { + ifdebug(TRAFFIC) logger(LOG_ERR, "Routing loop for packet from %s (%s)!", source->name, source->hostname); + return; + } - if(via && packet->len > via->mtu && via != myself) { - ifdebug(TRAFFIC) logger(LOG_INFO, _("Packet for %s (%s) length %d larger than MTU %d"), subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu); + if(directonly && subnet->owner != via) + return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO); + + if(via && packet->len > MAX(via->mtu, 590) && via != myself) { + ifdebug(TRAFFIC) logger(LOG_INFO, "Packet for %s (%s) length %d larger than MTU %d", subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu); if(packet->data[20] & 0x40) { - packet->len = via->mtu; - route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED); + packet->len = MAX(via->mtu, 590); + route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED); } else { - fragment_ipv4_packet(via, packet); + fragment_ipv4_packet(via, packet, ether_size); } return; } + clamp_mss(source, via, packet); + send_packet(subnet->owner, packet); } -static void route_ipv4(node_t *source, vpn_packet_t *packet) -{ - cp(); - +static void route_ipv4(node_t *source, vpn_packet_t *packet) { if(!checklength(source, packet, ether_size + ip_size)) return; - route_ipv4_unicast(source, packet); + if(broadcast_mode && (((packet->data[30] & 0xf0) == 0xe0) || ( + packet->data[30] == 255 && + packet->data[31] == 255 && + packet->data[32] == 255 && + packet->data[33] == 255))) + route_broadcast(source, packet); + else + route_ipv4_unicast(source, packet); } -/* RFC 2463 */ - -static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, uint8_t type, uint8_t code) -{ - struct ip6_hdr ip6; - struct icmp6_hdr icmp6 = {0}; - 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(3)) - return; - - cp(); - - /* Copy headers from packet to structs on the stack */ - - memcpy(&ip6, packet->data + ether_size, ip6_size); - - /* Remember original source and destination */ - - pseudo.ip6_src = ip6.ip6_dst; - pseudo.ip6_dst = ip6.ip6_src; - - pseudo.length = packet->len - ether_size; - - if(type == ICMP6_PACKET_TOO_BIG) - icmp6.icmp6_mtu = htonl(pseudo.length); - - if(pseudo.length >= IP_MSS - ip6_size - icmp6_size) - pseudo.length = IP_MSS - ip6_size - icmp6_size; - - /* Copy first part of original contents to ICMP message */ - - memmove(packet->data + ether_size + ip6_size + icmp6_size, packet->data + ether_size, pseudo.length); - - /* Fill in IPv6 header */ - - ip6.ip6_flow = htonl(0x60000000UL); - ip6.ip6_plen = htons(icmp6_size + pseudo.length); - ip6.ip6_nxt = IPPROTO_ICMPV6; - ip6.ip6_hlim = 255; - ip6.ip6_src = pseudo.ip6_src; - ip6.ip6_dst = pseudo.ip6_dst; - - /* Fill in ICMP header */ - - icmp6.icmp6_type = type; - icmp6.icmp6_code = code; - icmp6.icmp6_cksum = 0; - - /* Create pseudo header */ - - pseudo.length = htonl(icmp6_size + pseudo.length); - pseudo.next = htonl(IPPROTO_ICMPV6); - - /* Generate checksum */ - - checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); - checksum = inet_checksum(&icmp6, icmp6_size, checksum); - checksum = inet_checksum(packet->data + ether_size + ip6_size + icmp6_size, ntohl(pseudo.length) - icmp6_size, checksum); - - icmp6.icmp6_cksum = checksum; - - /* Copy structs on stack back to packet */ - - memcpy(packet->data + ether_size, &ip6, ip6_size); - memcpy(packet->data + ether_size + ip6_size, &icmp6, icmp6_size); - - packet->len = ether_size + ip6_size + ntohl(pseudo.length); - - send_packet(source, packet); -} - -static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) -{ +static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) { subnet_t *subnet; node_t *via; ipv6_t dest; - cp(); - memcpy(&dest, &packet->data[38], sizeof dest); subnet = lookup_subnet_ipv6(&dest); if(!subnet) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet from %s (%s): unknown IPv6 destination address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"), + ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet from %s (%s): unknown IPv6 destination address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx", source->name, source->hostname, ntohs(dest.x[0]), ntohs(dest.x[1]), @@ -481,39 +656,56 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) ntohs(dest.x[6]), ntohs(dest.x[7])); - route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR); + route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR); return; } if(subnet->owner == source) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Packet looping back to %s (%s)!"), source->name, source->hostname); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname); return; } if(!subnet->owner->status.reachable) - route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE); + return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE); + + if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) + return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN); + + if(decrement_ttl && source != myself && subnet->owner != myself) + if(!do_decrement_ttl(source, packet)) + return; via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via; - if(via && packet->len > via->mtu && via != myself) { - ifdebug(TRAFFIC) logger(LOG_INFO, _("Packet for %s (%s) length %d larger than MTU %d"), subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu); - packet->len = via->mtu; - route_ipv6_unreachable(source, packet, ICMP6_PACKET_TOO_BIG, 0); + if(via == source) { + ifdebug(TRAFFIC) logger(LOG_ERR, "Routing loop for packet from %s (%s)!", source->name, source->hostname); + return; + } + + if(directonly && subnet->owner != via) + return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN); + + if(via && packet->len > MAX(via->mtu, 1294) && via != myself) { + ifdebug(TRAFFIC) logger(LOG_INFO, "Packet for %s (%s) length %d larger than MTU %d", subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu); + packet->len = MAX(via->mtu, 1294); + route_ipv6_unreachable(source, packet, ether_size, ICMP6_PACKET_TOO_BIG, 0); return; } + clamp_mss(source, via, packet); + send_packet(subnet->owner, packet); } /* RFC 2461 */ -static void route_neighborsol(node_t *source, vpn_packet_t *packet) -{ +static void route_neighborsol(node_t *source, vpn_packet_t *packet) { struct ip6_hdr ip6; struct nd_neighbor_solicit ns; struct nd_opt_hdr opt; subnet_t *subnet; uint16_t checksum; + bool has_opt; struct { struct in6_addr ip6_src; /* source address */ @@ -522,13 +714,13 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) uint32_t next; } pseudo; - cp(); - - if(!checklength(source, packet, ether_size + ip6_size + ns_size + opt_size + ETH_ALEN)) + if(!checklength(source, packet, ether_size + ip6_size + ns_size)) return; + has_opt = packet->len >= ether_size + ip6_size + ns_size + opt_size + ETH_ALEN; + if(source != myself) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got neighbor solicitation request from %s (%s) while in router mode!"), source->name, source->hostname); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Got neighbor solicitation request from %s (%s) while in router mode!", source->name, source->hostname); return; } @@ -536,7 +728,8 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) memcpy(&ip6, packet->data + ether_size, ip6_size); memcpy(&ns, packet->data + ether_size + ip6_size, ns_size); - memcpy(&opt, packet->data + ether_size + ip6_size + ns_size, opt_size); + if(has_opt) + memcpy(&opt, packet->data + ether_size + ip6_size + ns_size, opt_size); /* First, snatch the source address from the neighbor solicitation packet */ @@ -546,8 +739,8 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) /* 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) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type neighbor solicitation request")); + (has_opt && opt.nd_opt_type != ND_OPT_SOURCE_LINKADDR)) { + ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet: received unknown type neighbor solicitation request"); return; } @@ -555,18 +748,23 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) pseudo.ip6_src = ip6.ip6_src; pseudo.ip6_dst = ip6.ip6_dst; - pseudo.length = htonl(ns_size + opt_size + ETH_ALEN); + if(has_opt) + pseudo.length = htonl(ns_size + opt_size + ETH_ALEN); + else + pseudo.length = htonl(ns_size); pseudo.next = htonl(IPPROTO_ICMPV6); /* Generate checksum */ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); checksum = inet_checksum(&ns, ns_size, checksum); - checksum = inet_checksum(&opt, opt_size, checksum); - checksum = inet_checksum(packet->data + ether_size + ip6_size + ns_size + opt_size, ETH_ALEN, checksum); + if(has_opt) { + checksum = inet_checksum(&opt, opt_size, checksum); + checksum = inet_checksum(packet->data + ether_size + ip6_size + ns_size + opt_size, ETH_ALEN, checksum); + } if(checksum) { - ifdebug(TRAFFIC) logger(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; } @@ -575,7 +773,7 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) subnet = lookup_subnet_ipv6((ipv6_t *) &ns.nd_ns_target); if(!subnet) { - ifdebug(TRAFFIC) logger(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]), @@ -593,6 +791,10 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) if(subnet->owner == myself) return; /* silently ignore */ + if(decrement_ttl) + if(!do_decrement_ttl(source, packet)) + return; + /* Create neighbor advertation reply */ memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN); /* copy destination address */ @@ -601,7 +803,8 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) ip6.ip6_dst = ip6.ip6_src; /* swap destination and source protocoll address */ ip6.ip6_src = ns.nd_ns_target; - memcpy(packet->data + ether_size + ip6_size + ns_size + opt_size, packet->data + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */ + if(has_opt) + memcpy(packet->data + ether_size + ip6_size + ns_size + opt_size, packet->data + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */ ns.nd_ns_cksum = 0; ns.nd_ns_type = ND_NEIGHBOR_ADVERT; @@ -612,15 +815,20 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) pseudo.ip6_src = ip6.ip6_src; pseudo.ip6_dst = ip6.ip6_dst; - pseudo.length = htonl(ns_size + opt_size + ETH_ALEN); + if(has_opt) + pseudo.length = htonl(ns_size + opt_size + ETH_ALEN); + else + pseudo.length = htonl(ns_size); pseudo.next = htonl(IPPROTO_ICMPV6); /* Generate checksum */ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); checksum = inet_checksum(&ns, ns_size, checksum); - checksum = inet_checksum(&opt, opt_size, checksum); - checksum = inet_checksum(packet->data + ether_size + ip6_size + ns_size + opt_size, ETH_ALEN, checksum); + if(has_opt) { + checksum = inet_checksum(&opt, opt_size, checksum); + checksum = inet_checksum(packet->data + ether_size + ip6_size + ns_size + opt_size, ETH_ALEN, checksum); + } ns.nd_ns_hdr.icmp6_cksum = checksum; @@ -628,15 +836,13 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) memcpy(packet->data + ether_size, &ip6, ip6_size); memcpy(packet->data + ether_size + ip6_size, &ns, ns_size); - memcpy(packet->data + ether_size + ip6_size + ns_size, &opt, opt_size); + if(has_opt) + memcpy(packet->data + ether_size + ip6_size + ns_size, &opt, opt_size); send_packet(source, packet); } -static void route_ipv6(node_t *source, vpn_packet_t *packet) -{ - cp(); - +static void route_ipv6(node_t *source, vpn_packet_t *packet) { if(!checklength(source, packet, ether_size + ip6_size)) return; @@ -645,24 +851,24 @@ static void route_ipv6(node_t *source, vpn_packet_t *packet) return; } - route_ipv6_unicast(source, packet); + if(broadcast_mode && packet->data[38] == 255) + route_broadcast(source, packet); + else + route_ipv6_unicast(source, packet); } /* RFC 826 */ -static void route_arp(node_t *source, vpn_packet_t *packet) -{ +static void route_arp(node_t *source, vpn_packet_t *packet) { struct ether_arp arp; subnet_t *subnet; struct in_addr addr; - cp(); - if(!checklength(source, packet, ether_size + arp_size)) return; if(source != myself) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got ARP request from %s (%s) while in router mode!"), source->name, source->hostname); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Got ARP request from %s (%s) while in router mode!", source->name, source->hostname); return; } @@ -679,7 +885,7 @@ static void route_arp(node_t *source, vpn_packet_t *packet) if(ntohs(arp.arp_hrd) != ARPHRD_ETHER || ntohs(arp.arp_pro) != ETH_P_IP || arp.arp_hln != ETH_ALEN || arp.arp_pln != sizeof(addr) || ntohs(arp.arp_op) != ARPOP_REQUEST) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type ARP request")); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet: received unknown type ARP request"); return; } @@ -688,7 +894,7 @@ static void route_arp(node_t *source, vpn_packet_t *packet) subnet = lookup_subnet_ipv4((ipv4_t *) &arp.arp_tpa); if(!subnet) { - ifdebug(TRAFFIC) logger(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; @@ -699,6 +905,10 @@ static void route_arp(node_t *source, vpn_packet_t *packet) if(subnet->owner == myself) return; /* silently ignore */ + if(decrement_ttl) + if(!do_decrement_ttl(source, packet)) + return; + memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN); /* copy destination address */ packet->data[ETH_ALEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */ @@ -717,9 +927,86 @@ static void route_arp(node_t *source, vpn_packet_t *packet) send_packet(source, packet); } -void route(node_t *source, vpn_packet_t *packet) -{ - cp(); +static void route_mac(node_t *source, vpn_packet_t *packet) { + subnet_t *subnet; + mac_t dest; + + /* Learn source address */ + + if(source == myself) { + mac_t src; + memcpy(&src, &packet->data[6], sizeof src); + learn_mac(&src); + } + + /* Lookup destination address */ + + memcpy(&dest, &packet->data[0], sizeof dest); + subnet = lookup_subnet_mac(NULL, &dest); + + if(!subnet) { + route_broadcast(source, packet); + return; + } + + if(subnet->owner == source) { + ifdebug(TRAFFIC) logger(LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname); + return; + } + + if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) + return; + + if(decrement_ttl && source != myself && subnet->owner != myself) + if(!do_decrement_ttl(source, packet)) + return; + + uint16_t type = packet->data[12] << 8 | packet->data[13]; + + if(priorityinheritance && type == ETH_P_IP && packet->len >= ether_size + ip_size) + packet->priority = packet->data[15]; + + // Handle packets larger than PMTU + + node_t *via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via; + + if(directonly && subnet->owner != via) + return; + + if(via && packet->len > via->mtu && via != myself) { + ifdebug(TRAFFIC) logger(LOG_INFO, "Packet for %s (%s) length %d larger than MTU %d", subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu); + length_t ethlen = 14; + + if(type == ETH_P_8021Q) { + type = packet->data[16] << 8 | packet->data[17]; + ethlen += 4; + } + + if(type == ETH_P_IP && packet->len > 576 + ethlen) { + if(packet->data[6 + ethlen] & 0x40) { + packet->len = via->mtu; + route_ipv4_unreachable(source, packet, ethlen, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED); + } else { + fragment_ipv4_packet(via, packet, ethlen); + } + return; + } else if(type == ETH_P_IPV6 && packet->len > 1280 + ethlen) { + packet->len = via->mtu; + route_ipv6_unreachable(source, packet, ethlen, ICMP6_PACKET_TOO_BIG, 0); + return; + } + } + + clamp_mss(source, via, packet); + + send_packet(subnet->owner, packet); +} + +void route(node_t *source, vpn_packet_t *packet) { + if(forwarding_mode == FMODE_KERNEL && source != myself) { + send_packet(myself, packet); + return; + } if(!checklength(source, packet, ether_size)) return; @@ -727,9 +1014,8 @@ void route(node_t *source, vpn_packet_t *packet) switch (routing_mode) { case RMODE_ROUTER: { - uint16_t type; + uint16_t type = packet->data[12] << 8 | packet->data[13]; - type = ntohs(*((uint16_t *)(&packet->data[12]))); switch (type) { case ETH_P_ARP: route_arp(source, packet); @@ -744,7 +1030,7 @@ void route(node_t *source, vpn_packet_t *packet) break; default: - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet from %s (%s): unknown type %hx"), source->name, source->hostname, type); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet from %s (%s): unknown type %hx", source->name, source->hostname, type); break; } } @@ -755,7 +1041,7 @@ void route(node_t *source, vpn_packet_t *packet) break; case RMODE_HUB: - broadcast_packet(source, packet); + route_broadcast(source, packet); break; } }