X-Git-Url: https://git.librecmc.org/?p=oweals%2Ftinc.git;a=blobdiff_plain;f=src%2Froute.c;h=3e86b40da011e5232a47caf747831c85a8ab121c;hp=ef6875955976ef7cafef22fdeb8c2bbfce498e11;hb=99763e34d52fcfe76b0bb9c7f3a17ace51cfdbfc;hpb=985d19caf20058db3c764f0f6fbeafa8bcc59fcc diff --git a/src/route.c b/src/route.c index ef68759..3e86b40 100644 --- a/src/route.c +++ b/src/route.c @@ -2,7 +2,7 @@ route.c -- routing Copyright (C) 2000-2005 Ivo Timmermans, 2000-2017 Guus Sliepen - 2015-2016 Vittorio Gambaletta + 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 @@ -68,12 +68,14 @@ static uint16_t inet_checksum(void *data, int len, uint16_t prevsum) { 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; } @@ -81,10 +83,11 @@ static uint16_t inet_checksum(void *data, int len, uint16_t prevsum) { 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; @@ -98,8 +101,9 @@ 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); return false; - } else + } else { return true; + } } static void swap_mac_addresses(vpn_packet_t *packet) { @@ -114,14 +118,15 @@ static void swap_mac_addresses(vpn_packet_t *packet) { 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)) + if(ratelimit(3)) { return; - + } + /* Swap Ethernet source and destination addresses */ swap_mac_addresses(packet); @@ -131,45 +136,51 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_ 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) { + if(type == ICMP_TIME_EXCEEDED && code == ICMP_EXC_TTL) { int sockfd = socket(AF_INET, SOCK_DGRAM, 0); - if (sockfd != -1) { + + 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))) { + + 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)) { + + 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) + 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) + 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; @@ -183,13 +194,13 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_ 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); @@ -197,7 +208,7 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_ 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); @@ -208,18 +219,19 @@ static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_ 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; + uint16_t checksum; 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(ratelimit(3)) + if(ratelimit(3)) { return; - + } + /* Swap Ethernet source and destination addresses */ swap_mac_addresses(packet); @@ -229,45 +241,51 @@ static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, length_ 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) { + if(type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT) { int sockfd = socket(AF_INET6, SOCK_DGRAM, 0); - if (sockfd != -1) { + + 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))) { + + 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)) { + + 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) + if(type == ICMP6_PACKET_TOO_BIG) { icmp6.icmp6_mtu = htonl(pseudo.length); - - if(pseudo.length >= IP_MSS - ip6_size - icmp6_size) + } + + 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; @@ -276,18 +294,18 @@ static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, length_ 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); @@ -298,9 +316,9 @@ static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, length_ 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); } @@ -313,56 +331,68 @@ static bool do_decrement_ttl(node_t *source, vpn_packet_t *packet) { ethlen += 4; } - switch (type) { - case ETH_P_IP: - if(!checklength(source, packet, ethlen + ip_size)) - return false; + 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; + 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); } - 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]; + return false; + } - 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; + 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]; - return true; + uint32_t checksum = packet->data[ethlen + 10] << 8 | packet->data[ethlen + 11]; + checksum += old + (~new & 0xFFFF); - case ETH_P_IPV6: - if(!checklength(source, packet, ethlen + ip6_size)) - return false; + while(checksum >> 16) { + checksum = (checksum & 0xFFFF) + (checksum >> 16); + } + + packet->data[ethlen + 10] = checksum >> 8; + packet->data[ethlen + 11] = checksum & 0xff; - 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; + 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); } - packet->data[ethlen + 7]--; + return false; + } + + packet->data[ethlen + 7]--; - return true; + return true; - default: - 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)) + if(!source || !via || !(via->options & OPTION_CLAMP_MSS)) { return; + } uint16_t mtu = source->mtu; - if(via != myself && via->mtu < mtu) + + if(via != myself && via->mtu < mtu) { mtu = via->mtu; + } /* Find TCP header */ int start = ether_size; @@ -373,53 +403,62 @@ static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *pac type = packet->data[16] << 8 | packet->data[17]; } - if(type == ETH_P_IP && packet->data[start + 9] == 6) + 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) + } else if(type == ETH_P_IPV6 && packet->data[start + 6] == 6) { start += 40; - else + } else { return; + } - if(packet->len <= start + 20) + 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) + 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) + 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]) + 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) + if(packet->data[start + 21 + i] < 2) { break; + } + i += packet->data[start + 21 + i]; continue; } - if(packet->data[start + 21] != 4) + 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) + 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 */ @@ -436,7 +475,7 @@ static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *pac break; } } - + static void learn_mac(mac_t *address) { subnet_t *subnet; avl_node_t *node; @@ -448,8 +487,8 @@ static void learn_mac(mac_t *address) { 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]); + 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; @@ -463,13 +502,16 @@ static void learn_mac(mac_t *address) { 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) { @@ -480,17 +522,22 @@ 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) { 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); @@ -501,8 +548,9 @@ void age_subnets(void) { static void route_broadcast(node_t *source, vpn_packet_t *packet) { if(decrement_ttl && source != myself) - if(!do_decrement_ttl(source, packet)) + if(!do_decrement_ttl(source, packet)) { return; + } broadcast_packet(source, packet); } @@ -515,13 +563,14 @@ static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet, length_t et 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) { @@ -536,7 +585,7 @@ static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet, length_t et 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); @@ -554,7 +603,7 @@ static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet, length_t et send_packet(dest, &fragment); ip_off += len / 8; - } + } } static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) { @@ -567,33 +616,39 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) { 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, 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) - return route_ipv4_unreachable(source, packet, ether_size, 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) - return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO); + 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)) + 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; @@ -601,12 +656,15 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) { ifdebug(TRAFFIC) logger(LOG_ERR, "Routing loop for packet from %s (%s)!", source->name, source->hostname); return; } - - if(directonly && subnet->owner != via) - return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO); + + 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, ether_size, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED); @@ -618,22 +676,24 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *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(broadcast_mode && (((packet->data[30] & 0xf0) == 0xe0) || ( - packet->data[30] == 255 && - packet->data[31] == 255 && - packet->data[32] == 255 && - packet->data[33] == 255))) + packet->data[30] == 255 && + packet->data[31] == 255 && + packet->data[32] == 255 && + packet->data[33] == 255))) { route_broadcast(source, packet); - else + } else { route_ipv4_unicast(source, packet); + } } static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) { @@ -646,15 +706,15 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) { 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])); + 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; @@ -665,28 +725,37 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) { return; } - if(!subnet->owner->status.reachable) - return route_ipv6_unreachable(source, packet, ether_size, 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) - return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN); + 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)) + if(decrement_ttl && source != myself && subnet->owner != myself) { + if(!do_decrement_ttl(source, packet)) { return; + } + } - if(priorityinheritance) + 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 == 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(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); @@ -696,7 +765,7 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) { } clamp_mss(source, via, packet); - + send_packet(subnet->owner, packet); } @@ -711,17 +780,18 @@ static void route_neighborsol(node_t *source, vpn_packet_t *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; @@ -731,18 +801,21 @@ 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); - 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; } @@ -751,16 +824,20 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) { 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); @@ -777,57 +854,64 @@ static void route_neighborsol(node_t *source, vpn_packet_t *packet) { 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)) + 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); @@ -839,25 +923,29 @@ 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); - 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(broadcast_mode && packet->data[38] == 255) + if(broadcast_mode && packet->data[38] == 255) { route_broadcast(source, packet); - else + } else { route_ipv6_unicast(source, packet); + } } /* RFC 826 */ @@ -867,8 +955,9 @@ static void route_arp(node_t *source, vpn_packet_t *packet) { 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); @@ -877,8 +966,9 @@ static void route_arp(node_t *source, vpn_packet_t *packet) { /* 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 */ @@ -887,7 +977,7 @@ static void route_arp(node_t *source, vpn_packet_t *packet) { /* 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; } @@ -898,29 +988,31 @@ static void route_arp(node_t *source, vpn_packet_t *packet) { 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 */ + } if(decrement_ttl) - if(!do_decrement_ttl(source, packet)) + 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 */ + 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(&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(&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 */ + 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 */ @@ -957,29 +1049,33 @@ static void route_mac(node_t *source, vpn_packet_t *packet) { return; } - if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) + 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)) + 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) + 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) + } 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) + 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; @@ -996,6 +1092,7 @@ static void route_mac(node_t *source, vpn_packet_t *packet) { } else { fragment_ipv4_packet(via, packet, ethlen); } + return; } else if(type == ETH_P_IPV6 && packet->len > 1280 + ethlen) { packet->len = via->mtu; @@ -1005,7 +1102,7 @@ static void route_mac(node_t *source, vpn_packet_t *packet) { } clamp_mss(source, via, packet); - + send_packet(subnet->owner, packet); } @@ -1015,40 +1112,40 @@ void route(node_t *source, vpn_packet_t *packet) { return; } - if(!checklength(source, packet, ether_size)) + if(!checklength(source, packet, ether_size)) { 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; - - 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: - route_broadcast(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; } }