Import Upstream version 1.0.27
This commit is contained in:
Guus Sliepen
parent
b33a93f7f6
commit
eed44cd331
44 changed files with 1672 additions and 932 deletions
509
src/route.c
509
src/route.c
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@ -2,6 +2,7 @@
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route.c -- routing
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Copyright (C) 2000-2005 Ivo Timmermans,
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2000-2014 Guus Sliepen <guus@tinc-vpn.org>
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2015 Vittorio Gambaletta
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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@ -101,6 +102,260 @@ static bool checklength(node_t *source, vpn_packet_t *packet, length_t length) {
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return true;
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}
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static void swap_mac_addresses(vpn_packet_t *packet) {
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mac_t tmp;
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memcpy(&tmp, &packet->data[0], sizeof tmp);
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memcpy(&packet->data[0], &packet->data[6], sizeof tmp);
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memcpy(&packet->data[6], &tmp, sizeof tmp);
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}
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/* RFC 792 */
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static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) {
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struct ip ip = {0};
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struct icmp icmp = {0};
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struct in_addr ip_src;
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struct in_addr ip_dst;
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uint32_t oldlen;
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if(ratelimit(3))
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return;
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/* Swap Ethernet source and destination addresses */
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swap_mac_addresses(packet);
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/* Copy headers from packet into properly aligned structs on the stack */
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memcpy(&ip, packet->data + ether_size, ip_size);
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/* Remember original source and destination */
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ip_src = ip.ip_src;
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ip_dst = ip.ip_dst;
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/* Try to reply with an IP address assigned to the local machine */
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if (type == ICMP_TIME_EXCEEDED && code == ICMP_EXC_TTL) {
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int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
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if (sockfd != -1) {
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struct sockaddr_in addr;
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memset(&addr, 0, sizeof(addr));
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addr.sin_family = AF_INET;
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addr.sin_addr = ip.ip_src;
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if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) {
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memset(&addr, 0, sizeof(addr));
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addr.sin_family = AF_INET;
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socklen_t addrlen = sizeof(addr);
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if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) {
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ip_dst = addr.sin_addr;
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}
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}
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close(sockfd);
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}
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}
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oldlen = packet->len - ether_size;
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if(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
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icmp.icmp_nextmtu = htons(packet->len - ether_size);
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if(oldlen >= IP_MSS - ip_size - icmp_size)
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oldlen = IP_MSS - ip_size - icmp_size;
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/* Copy first part of original contents to ICMP message */
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memmove(packet->data + ether_size + ip_size + icmp_size, packet->data + ether_size, oldlen);
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/* Fill in IPv4 header */
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ip.ip_v = 4;
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ip.ip_hl = ip_size / 4;
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ip.ip_tos = 0;
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ip.ip_len = htons(ip_size + icmp_size + oldlen);
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ip.ip_id = 0;
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ip.ip_off = 0;
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ip.ip_ttl = 255;
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ip.ip_p = IPPROTO_ICMP;
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ip.ip_sum = 0;
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ip.ip_src = ip_dst;
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ip.ip_dst = ip_src;
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ip.ip_sum = inet_checksum(&ip, ip_size, ~0);
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/* Fill in ICMP header */
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icmp.icmp_type = type;
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icmp.icmp_code = code;
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icmp.icmp_cksum = 0;
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icmp.icmp_cksum = inet_checksum(&icmp, icmp_size, ~0);
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icmp.icmp_cksum = inet_checksum(packet->data + ether_size + ip_size + icmp_size, oldlen, icmp.icmp_cksum);
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/* Copy structs on stack back to packet */
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memcpy(packet->data + ether_size, &ip, ip_size);
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memcpy(packet->data + ether_size + ip_size, &icmp, icmp_size);
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packet->len = ether_size + ip_size + icmp_size + oldlen;
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send_packet(source, packet);
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}
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/* RFC 2463 */
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static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) {
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struct ip6_hdr ip6;
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struct icmp6_hdr icmp6 = {0};
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uint16_t checksum;
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struct {
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struct in6_addr ip6_src; /* source address */
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struct in6_addr ip6_dst; /* destination address */
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uint32_t length;
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uint32_t next;
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} pseudo;
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if(ratelimit(3))
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return;
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/* Swap Ethernet source and destination addresses */
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swap_mac_addresses(packet);
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/* Copy headers from packet to structs on the stack */
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memcpy(&ip6, packet->data + ether_size, ip6_size);
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/* Remember original source and destination */
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pseudo.ip6_src = ip6.ip6_dst;
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pseudo.ip6_dst = ip6.ip6_src;
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/* Try to reply with an IP address assigned to the local machine */
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if (type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT) {
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int sockfd = socket(AF_INET6, SOCK_DGRAM, 0);
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if (sockfd != -1) {
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struct sockaddr_in6 addr;
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memset(&addr, 0, sizeof(addr));
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addr.sin6_family = AF_INET6;
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addr.sin6_addr = ip6.ip6_src;
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if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) {
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memset(&addr, 0, sizeof(addr));
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addr.sin6_family = AF_INET6;
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socklen_t addrlen = sizeof(addr);
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if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) {
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pseudo.ip6_src = addr.sin6_addr;
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}
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}
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close(sockfd);
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}
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}
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pseudo.length = packet->len - ether_size;
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if(type == ICMP6_PACKET_TOO_BIG)
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icmp6.icmp6_mtu = htonl(pseudo.length);
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if(pseudo.length >= IP_MSS - ip6_size - icmp6_size)
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pseudo.length = IP_MSS - ip6_size - icmp6_size;
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/* Copy first part of original contents to ICMP message */
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memmove(packet->data + ether_size + ip6_size + icmp6_size, packet->data + ether_size, pseudo.length);
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/* Fill in IPv6 header */
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ip6.ip6_flow = htonl(0x60000000UL);
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ip6.ip6_plen = htons(icmp6_size + pseudo.length);
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ip6.ip6_nxt = IPPROTO_ICMPV6;
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ip6.ip6_hlim = 255;
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ip6.ip6_src = pseudo.ip6_src;
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ip6.ip6_dst = pseudo.ip6_dst;
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/* Fill in ICMP header */
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icmp6.icmp6_type = type;
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icmp6.icmp6_code = code;
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icmp6.icmp6_cksum = 0;
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/* Create pseudo header */
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pseudo.length = htonl(icmp6_size + pseudo.length);
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pseudo.next = htonl(IPPROTO_ICMPV6);
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/* Generate checksum */
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checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
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checksum = inet_checksum(&icmp6, icmp6_size, checksum);
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checksum = inet_checksum(packet->data + ether_size + ip6_size + icmp6_size, ntohl(pseudo.length) - icmp6_size, checksum);
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icmp6.icmp6_cksum = checksum;
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/* Copy structs on stack back to packet */
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memcpy(packet->data + ether_size, &ip6, ip6_size);
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memcpy(packet->data + ether_size + ip6_size, &icmp6, icmp6_size);
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packet->len = ether_size + ip6_size + ntohl(pseudo.length);
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send_packet(source, packet);
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}
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static bool do_decrement_ttl(node_t *source, vpn_packet_t *packet) {
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uint16_t type = packet->data[12] << 8 | packet->data[13];
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length_t ethlen = ether_size;
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if(type == ETH_P_8021Q) {
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type = packet->data[16] << 8 | packet->data[17];
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ethlen += 4;
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}
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switch (type) {
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case ETH_P_IP:
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if(!checklength(source, packet, ethlen + ip_size))
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return false;
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if(packet->data[ethlen + 8] <= 1) {
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if(packet->data[ethlen + 11] != IPPROTO_ICMP || packet->data[ethlen + 32] != ICMP_TIME_EXCEEDED)
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route_ipv4_unreachable(source, packet, ethlen, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL);
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return false;
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}
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uint16_t old = packet->data[ethlen + 8] << 8 | packet->data[ethlen + 9];
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packet->data[ethlen + 8]--;
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uint16_t new = packet->data[ethlen + 8] << 8 | packet->data[ethlen + 9];
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uint32_t checksum = packet->data[ethlen + 10] << 8 | packet->data[ethlen + 11];
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checksum += old + (~new & 0xFFFF);
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while(checksum >> 16)
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checksum = (checksum & 0xFFFF) + (checksum >> 16);
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packet->data[ethlen + 10] = checksum >> 8;
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packet->data[ethlen + 11] = checksum & 0xff;
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return true;
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case ETH_P_IPV6:
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if(!checklength(source, packet, ethlen + ip6_size))
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return false;
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if(packet->data[ethlen + 7] <= 1) {
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if(packet->data[ethlen + 6] != IPPROTO_ICMPV6 || packet->data[ethlen + 40] != ICMP6_TIME_EXCEEDED)
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route_ipv6_unreachable(source, packet, ethlen, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT);
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return false;
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}
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packet->data[ethlen + 7]--;
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return true;
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default:
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return true;
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}
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}
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static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *packet) {
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if(!source || !via || !(via->options & OPTION_CLAMP_MSS))
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return;
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@ -160,7 +415,7 @@ static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *pac
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/* Found it */
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uint16_t oldmss = packet->data[start + 22 + i] << 8 | packet->data[start + 23 + i];
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uint16_t newmss = mtu - start - 20;
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uint16_t csum = packet->data[start + 16] << 8 | packet->data[start + 17];
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uint32_t csum = packet->data[start + 16] << 8 | packet->data[start + 17];
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if(oldmss <= newmss)
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break;
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@ -171,21 +426,16 @@ static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *pac
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packet->data[start + 22 + i] = newmss >> 8;
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packet->data[start + 23 + i] = newmss & 0xff;
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csum ^= 0xffff;
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csum -= oldmss;
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csum += oldmss ^ 0xffff;
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csum += newmss;
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csum = (csum & 0xffff) + (csum >> 16);
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csum += csum >> 16;
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csum ^= 0xffff;
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packet->data[start + 16] = csum >> 8;
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packet->data[start + 17] = csum & 0xff;
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packet->data[start + 17] = csum;
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break;
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}
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}
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static void swap_mac_addresses(vpn_packet_t *packet) {
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mac_t tmp;
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memcpy(&tmp, &packet->data[0], sizeof tmp);
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memcpy(&packet->data[0], &packet->data[6], sizeof tmp);
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memcpy(&packet->data[6], &tmp, sizeof tmp);
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}
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static void learn_mac(mac_t *address) {
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subnet_t *subnet;
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@ -249,77 +499,12 @@ void age_subnets(void) {
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}
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}
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/* RFC 792 */
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static void route_broadcast(node_t *source, vpn_packet_t *packet) {
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if(decrement_ttl && source != myself)
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if(!do_decrement_ttl(source, packet))
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return;
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static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) {
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struct ip ip = {0};
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struct icmp icmp = {0};
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struct in_addr ip_src;
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struct in_addr ip_dst;
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uint32_t oldlen;
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if(ratelimit(3))
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return;
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/* Swap Ethernet source and destination addresses */
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swap_mac_addresses(packet);
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/* Copy headers from packet into properly aligned structs on the stack */
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memcpy(&ip, packet->data + ether_size, ip_size);
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/* Remember original source and destination */
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ip_src = ip.ip_src;
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ip_dst = ip.ip_dst;
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oldlen = packet->len - ether_size;
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if(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
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icmp.icmp_nextmtu = htons(packet->len - ether_size);
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if(oldlen >= IP_MSS - ip_size - icmp_size)
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oldlen = IP_MSS - ip_size - icmp_size;
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/* Copy first part of original contents to ICMP message */
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memmove(packet->data + ether_size + ip_size + icmp_size, packet->data + ether_size, oldlen);
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/* Fill in IPv4 header */
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ip.ip_v = 4;
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ip.ip_hl = ip_size / 4;
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ip.ip_tos = 0;
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ip.ip_len = htons(ip_size + icmp_size + oldlen);
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ip.ip_id = 0;
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ip.ip_off = 0;
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ip.ip_ttl = 255;
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ip.ip_p = IPPROTO_ICMP;
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ip.ip_sum = 0;
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ip.ip_src = ip_dst;
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ip.ip_dst = ip_src;
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ip.ip_sum = inet_checksum(&ip, ip_size, ~0);
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/* Fill in ICMP header */
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icmp.icmp_type = type;
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icmp.icmp_code = code;
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icmp.icmp_cksum = 0;
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icmp.icmp_cksum = inet_checksum(&icmp, icmp_size, ~0);
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icmp.icmp_cksum = inet_checksum(packet->data + ether_size + ip_size + icmp_size, oldlen, icmp.icmp_cksum);
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/* Copy structs on stack back to packet */
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memcpy(packet->data + ether_size, &ip, ip_size);
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memcpy(packet->data + ether_size + ip_size, &icmp, icmp_size);
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packet->len = ether_size + ip_size + icmp_size + oldlen;
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send_packet(source, packet);
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broadcast_packet(source, packet);
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}
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/* RFC 791 */
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@ -403,6 +588,10 @@ static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
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if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself)
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return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
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if(decrement_ttl && source != myself && subnet->owner != myself)
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if(!do_decrement_ttl(source, packet))
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return;
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if(priorityinheritance)
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packet->priority = packet->data[15];
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@ -442,91 +631,11 @@ static void route_ipv4(node_t *source, vpn_packet_t *packet) {
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packet->data[31] == 255 &&
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packet->data[32] == 255 &&
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packet->data[33] == 255)))
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broadcast_packet(source, packet);
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route_broadcast(source, packet);
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else
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route_ipv4_unicast(source, packet);
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}
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/* RFC 2463 */
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static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) {
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struct ip6_hdr ip6;
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struct icmp6_hdr icmp6 = {0};
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uint16_t checksum;
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struct {
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struct in6_addr ip6_src; /* source address */
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struct in6_addr ip6_dst; /* destination address */
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uint32_t length;
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uint32_t next;
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} pseudo;
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if(ratelimit(3))
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return;
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/* Swap Ethernet source and destination addresses */
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swap_mac_addresses(packet);
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/* Copy headers from packet to structs on the stack */
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memcpy(&ip6, packet->data + ether_size, ip6_size);
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/* Remember original source and destination */
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pseudo.ip6_src = ip6.ip6_dst;
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pseudo.ip6_dst = ip6.ip6_src;
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pseudo.length = packet->len - ether_size;
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if(type == ICMP6_PACKET_TOO_BIG)
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icmp6.icmp6_mtu = htonl(pseudo.length);
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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) {
|
||||
subnet_t *subnet;
|
||||
node_t *via;
|
||||
|
|
@ -562,6 +671,10 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
|
|||
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 == source) {
|
||||
|
|
@ -678,6 +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 */
|
||||
|
|
@ -735,7 +852,7 @@ static void route_ipv6(node_t *source, vpn_packet_t *packet) {
|
|||
}
|
||||
|
||||
if(broadcast_mode && packet->data[38] == 255)
|
||||
broadcast_packet(source, packet);
|
||||
route_broadcast(source, packet);
|
||||
else
|
||||
route_ipv6_unicast(source, packet);
|
||||
}
|
||||
|
|
@ -788,6 +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 */
|
||||
|
||||
|
|
@ -824,7 +945,7 @@ static void route_mac(node_t *source, vpn_packet_t *packet) {
|
|||
subnet = lookup_subnet_mac(NULL, &dest);
|
||||
|
||||
if(!subnet) {
|
||||
broadcast_packet(source, packet);
|
||||
route_broadcast(source, packet);
|
||||
return;
|
||||
}
|
||||
|
||||
|
|
@ -836,6 +957,10 @@ static void route_mac(node_t *source, vpn_packet_t *packet) {
|
|||
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)
|
||||
|
|
@ -877,58 +1002,6 @@ static void route_mac(node_t *source, vpn_packet_t *packet) {
|
|||
send_packet(subnet->owner, 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;
|
||||
}
|
||||
}
|
||||
|
||||
void route(node_t *source, vpn_packet_t *packet) {
|
||||
if(forwarding_mode == FMODE_KERNEL && source != myself) {
|
||||
send_packet(myself, packet);
|
||||
|
|
@ -938,10 +1011,6 @@ void route(node_t *source, vpn_packet_t *packet) {
|
|||
if(!checklength(source, packet, ether_size))
|
||||
return;
|
||||
|
||||
if(decrement_ttl && source != myself)
|
||||
if(!do_decrement_ttl(source, packet))
|
||||
return;
|
||||
|
||||
switch (routing_mode) {
|
||||
case RMODE_ROUTER:
|
||||
{
|
||||
|
|
@ -972,7 +1041,7 @@ void route(node_t *source, vpn_packet_t *packet) {
|
|||
break;
|
||||
|
||||
case RMODE_HUB:
|
||||
broadcast_packet(source, packet);
|
||||
route_broadcast(source, packet);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue