Reformat all code using astyle.
[tinc] / src / route.c
index ef68759..7530e42 100644 (file)
@@ -2,7 +2,7 @@
     route.c -- routing
     Copyright (C) 2000-2005 Ivo Timmermans,
                   2000-2017 Guus Sliepen <guus@tinc-vpn.org>
-                 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;
+               }
 
-                       return true;
+               packet->data[ethlen + 7]--;
 
-               default:
-                       return true;
+               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 +616,37 @@ 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)
+       if(!subnet->owner->status.reachable) {
                return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_UNREACH);
+       }
 
-       if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself)
+       if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself) {
                return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+       }
 
        if(decrement_ttl && source != myself && subnet->owner != myself)
-               if(!do_decrement_ttl(source, packet))
+               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 +654,14 @@ 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)
+
+       if(directonly && subnet->owner != via) {
                return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
+       }
 
        if(via && packet->len > MAX(via->mtu, 590) && via != myself) {
                ifdebug(TRAFFIC) logger(LOG_INFO, "Packet for %s (%s) length %d larger than MTU %d", subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu);
+
                if(packet->data[20] & 0x40) {
                        packet->len = MAX(via->mtu, 590);
                        route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED);
@@ -618,22 +673,24 @@ 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 +703,15 @@ 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 +722,33 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
                return;
        }
 
-       if(!subnet->owner->status.reachable)
+       if(!subnet->owner->status.reachable) {
                return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE);
+       }
 
-       if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself)
+       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))
+               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)
+
+       if(directonly && subnet->owner != via) {
                return route_ipv6_unreachable(source, packet, ether_size, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
+       }
 
        if(via && packet->len > MAX(via->mtu, 1294) && via != myself) {
                ifdebug(TRAFFIC) logger(LOG_INFO, "Packet for %s (%s) length %d larger than MTU %d", subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu);
@@ -696,7 +758,7 @@ static void route_ipv6_unicast(node_t *source, vpn_packet_t *packet) {
        }
 
        clamp_mss(source, via, packet);
+
        send_packet(subnet->owner, packet);
 }
 
@@ -711,17 +773,18 @@ 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 +794,21 @@ 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 +817,20 @@ 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 +847,64 @@ 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 +916,29 @@ 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 +948,9 @@ 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 +959,9 @@ 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 +970,7 @@ 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 +981,31 @@ 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 +1042,33 @@ 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 +1085,7 @@ 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 +1095,7 @@ static void route_mac(node_t *source, vpn_packet_t *packet) {
        }
 
        clamp_mss(source, via, packet);
+
        send_packet(subnet->owner, packet);
 }
 
@@ -1015,40 +1105,40 @@ 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;
        }
 }