/*
route.c -- routing
Copyright (C) 2000-2005 Ivo Timmermans,
- 2000-2009 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2017 Guus Sliepen <guus@tinc-vpn.org>
+ 2015-2016 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
#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;
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);
-#define max(a, b) ((a) > (b) ? (a) : (b))
+
+#ifndef MAX
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#endif
/* RFC 1071 */
checksum += *p++;
len -= 2;
}
-
- if(len)
+
+ if(len) {
checksum += *(uint8_t *)p;
+ }
- while(checksum >> 16)
+ while(checksum >> 16) {
checksum = (checksum & 0xFFFF) + (checksum >> 16);
+ }
return ~checksum;
}
static bool ratelimit(int frequency) {
static time_t lasttime = 0;
static int count = 0;
-
+
if(lasttime == now) {
- if(++count > frequency)
+ if(count >= frequency) {
return true;
+ }
} else {
lasttime = now;
count = 0;
}
+ count++;
return false;
}
if(packet->len < length) {
ifdebug(TRAFFIC) logger(LOG_WARNING, "Got too short packet from %s (%s)", source->name, source->hostname);
return false;
- } else
+ } else {
return true;
+ }
+}
+
+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, length_t ether_size, uint8_t type, uint8_t code) {
+ struct ip ip = {0};
+ struct icmp icmp = {0};
+
+ struct in_addr ip_src;
+ struct in_addr ip_dst;
+ uint32_t oldlen;
+
+ if(ratelimit(3)) {
+ return;
+ }
+
+ /* Swap Ethernet source and destination addresses */
+
+ swap_mac_addresses(packet);
+
+ /* Copy headers from packet into properly aligned structs on the stack */
+
+ memcpy(&ip, packet->data + ether_size, ip_size);
+
+ /* Remember original source and destination */
+
+ 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) {
+ icmp.icmp_nextmtu = htons(packet->len - ether_size);
+ }
+
+ if(oldlen >= IP_MSS - ip_size - icmp_size) {
+ oldlen = IP_MSS - ip_size - icmp_size;
+ }
+
+ /* Copy first part of original contents to ICMP message */
+
+ memmove(packet->data + ether_size + ip_size + icmp_size, packet->data + ether_size, oldlen);
+
+ /* Fill in IPv4 header */
+
+ ip.ip_v = 4;
+ ip.ip_hl = ip_size / 4;
+ ip.ip_tos = 0;
+ ip.ip_len = htons(ip_size + icmp_size + oldlen);
+ ip.ip_id = 0;
+ ip.ip_off = 0;
+ ip.ip_ttl = 255;
+ ip.ip_p = IPPROTO_ICMP;
+ ip.ip_sum = 0;
+ ip.ip_src = ip_dst;
+ ip.ip_dst = ip_src;
+
+ ip.ip_sum = inet_checksum(&ip, ip_size, ~0);
+
+ /* Fill in ICMP header */
+
+ icmp.icmp_type = type;
+ icmp.icmp_code = code;
+ icmp.icmp_cksum = 0;
+
+ icmp.icmp_cksum = inet_checksum(&icmp, icmp_size, ~0);
+ icmp.icmp_cksum = inet_checksum(packet->data + ether_size + ip_size + icmp_size, oldlen, icmp.icmp_cksum);
+
+ /* Copy structs on stack back to packet */
+
+ memcpy(packet->data + ether_size, &ip, ip_size);
+ memcpy(packet->data + ether_size + ip_size, &icmp, icmp_size);
+
+ packet->len = ether_size + ip_size + icmp_size + oldlen;
+
+ send_packet(source, packet);
}
-void clamp_mss(node_t *source, node_t *via, vpn_packet_t *packet) {
- int i;
- int len = ((packet->data[46] >> 4) - 5) * 4;
+/* 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[54 + i] == 0)
+ if(packet->data[start + 20 + i] == 0) {
break;
+ }
- if(packet->data[54 + i] == 1) {
+ if(packet->data[start + 20 + i] == 1) {
i++;
continue;
}
- if(i > len - 2 || i > len - packet->data[55 + i])
+ if(i > len - 2 || i > len - packet->data[start + 21 + i]) {
break;
+ }
- if(packet->data[54 + i] != 2) {
- if(packet->data[55 + i] < 2)
+ if(packet->data[start + 20 + i] != 2) {
+ if(packet->data[start + 21 + i] < 2) {
break;
- i += packet->data[55 + i];
+ }
+
+ i += packet->data[start + 21 + i];
continue;
}
- if(packet->data[55] != 4)
+ if(packet->data[start + 21] != 4) {
break;
+ }
- uint16_t oldmss = packet->data[56 + i] << 8 | packet->data[57 + i];
- uint16_t newmss = via->mtu - 54;
- uint16_t csum = packet->data[50] << 8 | packet->data[51];
+ /* 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)
+ if(oldmss <= newmss) {
break;
-
+ }
+
ifdebug(TRAFFIC) logger(LOG_INFO, "Clamping MSS of packet from %s to %s to %d", source->name, via->name, newmss);
- packet->data[56 + i] = newmss >> 8;
- packet->data[57 + i] = newmss & 0xff;
+ /* 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;
+ csum += oldmss ^ 0xffff;
csum += newmss;
+ csum = (csum & 0xffff) + (csum >> 16);
+ csum += csum >> 16;
csum ^= 0xffff;
- packet->data[50] = csum >> 8;
- packet->data[51] = csum & 0xff;
+ packet->data[start + 16] = csum >> 8;
+ packet->data[start + 17] = csum;
break;
}
}
-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);
-}
-
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) {
- 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]);
+ 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->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)
+
+ if(c->status.active) {
send_add_subnet(c, subnet);
+ }
}
}
- if(subnet->expires)
+ if(subnet->expires) {
subnet->expires = now + macexpire;
+ }
}
void age_subnets(void) {
for(node = myself->subnet_tree->head; node; node = next) {
next = node->next;
s = node->data;
- if(s->expires && s->expires < now) {
+
+ if(s->expires && s->expires <= now) {
ifdebug(TRAFFIC) {
char netstr[MAXNETSTR];
- if(net2str(netstr, sizeof netstr, s))
+
+ 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)
+
+ if(c->status.active) {
send_del_subnet(c, s);
+ }
}
+ subnet_update(myself, s, false);
subnet_del(myself, s);
}
}
}
-/* RFC 792 */
-
-static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t type, uint8_t code) {
- struct ip ip = {0};
- struct icmp icmp = {0};
-
- struct in_addr ip_src;
- struct in_addr ip_dst;
- uint32_t oldlen;
-
- if(ratelimit(3))
- return;
-
- /* Swap Ethernet source and destination addresses */
-
- swap_mac_addresses(packet);
-
- /* Copy headers from packet into properly aligned structs on the stack */
-
- memcpy(&ip, packet->data + ether_size, ip_size);
-
- /* Remember original source and destination */
-
- ip_src = ip.ip_src;
- ip_dst = ip.ip_dst;
-
- oldlen = packet->len - ether_size;
-
- if(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
- icmp.icmp_nextmtu = htons(packet->len - ether_size);
-
- if(oldlen >= IP_MSS - ip_size - icmp_size)
- oldlen = IP_MSS - ip_size - icmp_size;
-
- /* Copy first part of original contents to ICMP message */
-
- memmove(packet->data + ether_size + ip_size + icmp_size, packet->data + ether_size, oldlen);
-
- /* Fill in IPv4 header */
-
- ip.ip_v = 4;
- ip.ip_hl = ip_size / 4;
- ip.ip_tos = 0;
- ip.ip_len = htons(ip_size + icmp_size + oldlen);
- ip.ip_id = 0;
- ip.ip_off = 0;
- ip.ip_ttl = 255;
- ip.ip_p = IPPROTO_ICMP;
- ip.ip_sum = 0;
- ip.ip_src = ip_dst;
- ip.ip_dst = ip_src;
-
- ip.ip_sum = inet_checksum(&ip, ip_size, ~0);
-
- /* Fill in ICMP header */
-
- icmp.icmp_type = type;
- icmp.icmp_code = code;
- icmp.icmp_cksum = 0;
-
- icmp.icmp_cksum = inet_checksum(&icmp, icmp_size, ~0);
- icmp.icmp_cksum = inet_checksum(packet->data + ether_size + ip_size + icmp_size, oldlen, icmp.icmp_cksum);
-
- /* Copy structs on stack back to packet */
-
- memcpy(packet->data + ether_size, &ip, ip_size);
- memcpy(packet->data + ether_size + ip_size, &icmp, icmp_size);
-
- packet->len = ether_size + ip_size + icmp_size + oldlen;
+static void route_broadcast(node_t *source, vpn_packet_t *packet) {
+ if(decrement_ttl && source != myself)
+ if(!do_decrement_ttl(source, packet)) {
+ return;
+ }
- send_packet(source, packet);
+ 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;
-
+
memcpy(&ip, packet->data + ether_size, ip_size);
fragment.priority = packet->priority;
- if(ip.ip_hl != ip_size / 4)
+ if(ip.ip_hl != ip_size / 4) {
return;
-
+ }
+
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;
}
ip_off = ntohs(ip.ip_off);
origf = ip_off & ~IP_OFFMASK;
ip_off &= IP_OFFMASK;
-
+
while(todo) {
len = todo > maxlen ? maxlen : todo;
memcpy(fragment.data + ether_size + ip_size, offset, len);
send_packet(dest, &fragment);
ip_off += len / 8;
- }
+ }
}
static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
node_t *via;
ipv4_t dest;
- memcpy(&dest, &packet->data[30], sizeof dest);
+ 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",
- source->name, source->hostname,
- dest.x[0],
- dest.x[1],
- dest.x[2],
- dest.x[3]);
+ 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);
return;
}
- if(!subnet->owner->status.reachable)
- route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNREACH);
+ if(!subnet->owner->status.reachable) {
+ route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_UNREACH);
+ return;
+ }
+
+ if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) {
+ route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+ return;
+ }
+
+ if(decrement_ttl && source != myself && subnet->owner != myself)
+ if(!do_decrement_ttl(source, packet)) {
+ return;
+ }
- if(priorityinheritance)
+ if(priorityinheritance) {
packet->priority = packet->data[15];
+ }
via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
-
- if(via && packet->len > max(via->mtu, 590) && via != myself) {
+
+ 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) {
+ route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+ return;
+ }
+
+ 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 = max(via->mtu, 590);
- 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;
}
- if(via && via != myself && packet->data[23] == 6 && packet->len >= 58 && (packet->data[46] >> 4) > 5)
- clamp_mss(source, via, packet);
-
+ clamp_mss(source, via, packet);
+
send_packet(subnet->owner, packet);
}
static void route_ipv4(node_t *source, vpn_packet_t *packet) {
- if(!checklength(source, packet, ether_size + ip_size))
+ if(!checklength(source, packet, ether_size + ip_size)) {
return;
+ }
- if(((packet->data[30] & 0xf0) == 0xe0) || (
- packet->data[30] == 255 &&
- packet->data[31] == 255 &&
- packet->data[32] == 255 &&
- packet->data[33] == 255))
- broadcast_packet(source, packet);
- else
+ 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;
-
- /* 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;
-
- 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) {
node_t *via;
ipv6_t dest;
- memcpy(&dest, &packet->data[38], sizeof dest);
+ 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",
- source->name, source->hostname,
- ntohs(dest.x[0]),
- ntohs(dest.x[1]),
- ntohs(dest.x[2]),
- ntohs(dest.x[3]),
- ntohs(dest.x[4]),
- ntohs(dest.x[5]),
- ntohs(dest.x[6]),
- ntohs(dest.x[7]));
-
- route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR);
+ source->name, source->hostname,
+ ntohs(dest.x[0]),
+ ntohs(dest.x[1]),
+ ntohs(dest.x[2]),
+ ntohs(dest.x[3]),
+ ntohs(dest.x[4]),
+ ntohs(dest.x[5]),
+ ntohs(dest.x[6]),
+ ntohs(dest.x[7]));
+
+ route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR);
return;
}
return;
}
- if(!subnet->owner->status.reachable)
- route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE);
+ if(!subnet->owner->status.reachable) {
+ route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE);
+ return;
+ }
+
+ if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) {
+ route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+ return;
+ }
+
+ if(decrement_ttl && source != myself && subnet->owner != myself) {
+ if(!do_decrement_ttl(source, packet)) {
+ return;
+ }
+ }
+
+ if(priorityinheritance) {
+ packet->priority = ((packet->data[14] & 0x0f) << 4) | (packet->data[15] >> 4);
+ }
via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
-
- if(via && packet->len > max(via->mtu, 1294) && via != myself) {
+
+ 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) {
+ route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+ return;
+ }
+
+ 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, ICMP6_PACKET_TOO_BIG, 0);
+ 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);
}
bool has_opt;
struct {
- struct in6_addr ip6_src; /* source address */
- struct in6_addr ip6_dst; /* destination address */
+ struct in6_addr ip6_src; /* source address */
+ struct in6_addr ip6_dst; /* destination address */
uint32_t length;
uint32_t next;
} pseudo;
- if(!checklength(source, packet, ether_size + ip6_size + ns_size))
+ 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);
return;
memcpy(&ip6, packet->data + ether_size, ip6_size);
memcpy(&ns, packet->data + ether_size + ip6_size, ns_size);
- if(has_opt)
+
+ 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 */
- if(overwrite_mac)
+ if(overwrite_mac) {
memcpy(mymac.x, packet->data + ETH_ALEN, ETH_ALEN);
+ }
/* Check if this is a valid neighbor solicitation request */
if(ns.nd_ns_hdr.icmp6_type != ND_NEIGHBOR_SOLICIT ||
- (has_opt && opt.nd_opt_type != ND_OPT_SOURCE_LINKADDR)) {
+ (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;
}
pseudo.ip6_src = ip6.ip6_src;
pseudo.ip6_dst = ip6.ip6_dst;
- if(has_opt)
+
+ if(has_opt) {
pseudo.length = htonl(ns_size + opt_size + ETH_ALEN);
- else
+ } 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);
+
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(!subnet) {
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]));
+ 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;
}
/* Check if it is for our own subnet */
- if(subnet->owner == myself)
- return; /* silently ignore */
+ 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 */
- packet->data[ETH_ALEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */
+ 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 */
- ip6.ip6_dst = ip6.ip6_src; /* swap destination and source protocoll address */
+ ip6.ip6_dst = ip6.ip6_src; /* swap destination and source protocoll address */
ip6.ip6_src = ns.nd_ns_target;
- 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 */
+ 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;
- ns.nd_ns_reserved = htonl(0x40000000UL); /* Set solicited flag */
+ ns.nd_ns_reserved = htonl(0x40000000UL); /* Set solicited flag */
opt.nd_opt_type = ND_OPT_TARGET_LINKADDR;
/* Create pseudo header */
pseudo.ip6_src = ip6.ip6_src;
pseudo.ip6_dst = ip6.ip6_dst;
- if(has_opt)
+
+ if(has_opt) {
pseudo.length = htonl(ns_size + opt_size + ETH_ALEN);
- else
+ } 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);
+
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);
memcpy(packet->data + ether_size, &ip6, ip6_size);
memcpy(packet->data + ether_size + ip6_size, &ns, ns_size);
- if(has_opt)
+
+ 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) {
- if(!checklength(source, packet, ether_size + ip6_size))
+ if(!checklength(source, packet, ether_size + ip6_size)) {
return;
+ }
if(packet->data[20] == IPPROTO_ICMPV6 && checklength(source, packet, ether_size + ip6_size + icmp6_size) && packet->data[54] == ND_NEIGHBOR_SOLICIT) {
route_neighborsol(source, packet);
return;
}
- if(packet->data[38] == 255)
- broadcast_packet(source, packet);
- else
+ if(broadcast_mode && packet->data[38] == 255) {
+ route_broadcast(source, packet);
+ } else {
route_ipv6_unicast(source, packet);
+ }
}
/* RFC 826 */
subnet_t *subnet;
struct in_addr addr;
- if(!checklength(source, packet, ether_size + arp_size))
+ 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);
/* First, snatch the source address from the ARP packet */
- if(overwrite_mac)
+ if(overwrite_mac) {
memcpy(mymac.x, packet->data + ETH_ALEN, ETH_ALEN);
+ }
/* Copy headers from packet to structs on the stack */
/* Check if this is a valid ARP request */
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) {
+ 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");
return;
}
if(!subnet) {
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]);
+ arp.arp_tpa[0], arp.arp_tpa[1], arp.arp_tpa[2],
+ arp.arp_tpa[3]);
return;
}
/* Check if it is for our own subnet */
- if(subnet->owner == myself)
- return; /* silently ignore */
+ if(subnet->owner == myself) {
+ return; /* silently ignore */
+ }
- 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 */
+ if(decrement_ttl)
+ if(!do_decrement_ttl(source, packet)) {
+ return;
+ }
- memcpy(&addr, arp.arp_tpa, sizeof(addr)); /* save protocol addr */
- memcpy(arp.arp_tpa, arp.arp_spa, sizeof(addr)); /* swap destination and source protocol address */
- memcpy(arp.arp_spa, &addr, sizeof(addr)); /* ... */
+ 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 */
- memcpy(arp.arp_tha, arp.arp_sha, ETH_ALEN); /* set target hard/proto addr */
- memcpy(arp.arp_sha, packet->data + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */
+ memcpy(&addr, arp.arp_tpa, sizeof(addr)); /* save protocol addr */
+ memcpy(arp.arp_tpa, arp.arp_spa, sizeof(addr)); /* swap destination and source protocol address */
+ memcpy(arp.arp_spa, &addr, sizeof(addr)); /* ... */
+
+ memcpy(arp.arp_tha, arp.arp_sha, ETH_ALEN); /* set target hard/proto addr */
+ memcpy(arp.arp_sha, packet->data + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */
arp.arp_op = htons(ARPOP_REPLY);
/* Copy structs on stack back to packet */
if(source == myself) {
mac_t src;
- memcpy(&src, &packet->data[6], sizeof src);
+ memcpy(&src, &packet->data[6], sizeof(src));
learn_mac(&src);
}
/* Lookup destination address */
- memcpy(&dest, &packet->data[0], sizeof dest);
+ memcpy(&dest, &packet->data[0], sizeof(dest));
subnet = lookup_subnet_mac(NULL, &dest);
if(!subnet) {
- broadcast_packet(source, packet);
+ route_broadcast(source, packet);
return;
}
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) {
+ if(type == ETH_P_IP && packet->len >= ether_size + ip_size) {
+ packet->priority = packet->data[15];
+ } else if(type == ETH_P_IPV6 && packet->len >= ether_size + ip6_size) {
+ packet->priority = ((packet->data[14] & 0x0f) << 4) | (packet->data[15] >> 4);
+ }
+ }
+
// 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);
- uint16_t type = packet->data[12] << 8 | packet->data[13];
- if(type == ETH_P_IP && packet->len > 590) {
- if(packet->data[20] & 0x40) {
+ 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, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED);
+ route_ipv4_unreachable(source, packet, ethlen, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED);
} else {
- fragment_ipv4_packet(via, packet);
+ fragment_ipv4_packet(via, packet, ethlen);
}
+
return;
- } else if(type == ETH_P_IPV6 && packet->len > 1294) {
+ } else if(type == ETH_P_IPV6 && packet->len > 1280 + ethlen) {
packet->len = via->mtu;
- route_ipv6_unreachable(source, packet, ICMP6_PACKET_TOO_BIG, 0);
+ route_ipv6_unreachable(source, packet, ethlen, ICMP6_PACKET_TOO_BIG, 0);
return;
}
}
- if(via && via != myself && (packet->data[12] << 8 | packet->data[13]) == ETH_P_IP && packet->len >= 58 && packet->data[23] == 6 && (packet->data[46] >> 4) > 5)
- clamp_mss(source, via, packet);
-
+ clamp_mss(source, via, packet);
+
send_packet(subnet->owner, packet);
}
void route(node_t *source, vpn_packet_t *packet) {
- if(!checklength(source, packet, ether_size))
+ if(forwarding_mode == FMODE_KERNEL && source != myself) {
+ send_packet(myself, packet);
return;
+ }
- switch (routing_mode) {
- case RMODE_ROUTER:
- {
- uint16_t type = packet->data[12] << 8 | packet->data[13];
-
- switch (type) {
- case ETH_P_ARP:
- route_arp(source, packet);
- break;
+ if(!checklength(source, packet, ether_size)) {
+ return;
+ }
- case ETH_P_IP:
- route_ipv4(source, packet);
- break;
+ switch(routing_mode) {
+ case RMODE_ROUTER: {
+ uint16_t type = packet->data[12] << 8 | packet->data[13];
- case ETH_P_IPV6:
- route_ipv6(source, packet);
- break;
+ switch(type) {
+ case ETH_P_ARP:
+ route_arp(source, packet);
+ break;
- default:
- ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet from %s (%s): unknown type %hx", source->name, source->hostname, type);
- break;
- }
- }
+ case ETH_P_IP:
+ route_ipv4(source, packet);
break;
- case RMODE_SWITCH:
- route_mac(source, packet);
+ case ETH_P_IPV6:
+ route_ipv6(source, packet);
break;
- case RMODE_HUB:
- broadcast_packet(source, packet);
+ default:
+ ifdebug(TRAFFIC) logger(LOG_WARNING, "Cannot route packet from %s (%s): unknown type %hx", source->name, source->hostname, type);
break;
+ }
+ }
+ break;
+
+ case RMODE_SWITCH:
+ route_mac(source, packet);
+ break;
+
+ case RMODE_HUB:
+ route_broadcast(source, packet);
+ break;
}
}
projects / tinc / blobdiff