checksum += *p++;
len -= 2;
}
-
+
if(len)
checksum += *(uint8_t *)p;
static time_t lasttime = 0;
static int count = 0;
time_t now = time(NULL);
-
+
if(lasttime == now) {
if(count >= frequency)
return true;
if(oldmss <= newmss)
break;
-
+
logger(DEBUG_TRAFFIC, LOG_INFO, "Clamping MSS of packet from %s to %s to %d", source->name, via->name, newmss);
/* Update the MSS value and the checksum */
memcpy(&packet->data[0], &packet->data[6], sizeof tmp);
memcpy(&packet->data[6], &tmp, sizeof tmp);
}
-
+
static void age_subnets(int fd, short events, void *data) {
bool left = false;
time_t now = time(NULL);
static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, uint8_t type, uint8_t code) {
struct ip ip = {0};
struct icmp icmp = {0};
-
+
struct in_addr ip_src;
struct in_addr ip_dst;
uint32_t oldlen;
if(ratelimit(3))
return;
-
+
/* Swap Ethernet source and destination addresses */
swap_mac_addresses(packet);
memcpy(&ip, packet->data + ether_size, ip_size);
/* Remember original source and destination */
-
+
ip_src = ip.ip_src;
ip_dst = ip.ip_dst;
if(oldlen >= IP_MSS - ip_size - icmp_size)
oldlen = IP_MSS - ip_size - icmp_size;
-
+
/* Copy first part of original contents to ICMP message */
-
+
memmove(packet->data + ether_size + ip_size + icmp_size, packet->data + ether_size, oldlen);
/* Fill in IPv4 header */
-
+
ip.ip_v = 4;
ip.ip_hl = ip_size / 4;
ip.ip_tos = 0;
ip.ip_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);
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);
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)
return;
-
+
todo = ntohs(ip.ip_len) - ip_size;
if(ether_size + ip_size + todo != packet->len) {
ip_off = ntohs(ip.ip_off);
origf = ip_off & ~IP_OFFMASK;
ip_off &= IP_OFFMASK;
-
+
while(todo) {
len = todo > maxlen ? maxlen : todo;
memcpy(fragment.data + ether_size + ip_size, offset, len);
send_packet(dest, &fragment);
ip_off += len / 8;
- }
+ }
}
static void route_ipv4_unicast(node_t *source, vpn_packet_t *packet) {
route_ipv4_unreachable(source, packet, ICMP_DEST_UNREACH, ICMP_NET_UNKNOWN);
return;
}
-
+
if(subnet->owner == source) {
logger(DEBUG_TRAFFIC, LOG_WARNING, "Packet looping back to %s (%s)!", source->name, source->hostname);
return;
logger(DEBUG_TRAFFIC, 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, ICMP_DEST_UNREACH, ICMP_NET_ANO);
}
clamp_mss(source, via, packet);
-
+
send_packet(subnet->owner, packet);
}
static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, uint8_t type, uint8_t code) {
struct ip6_hdr ip6;
struct icmp6_hdr icmp6 = {0};
- uint16_t checksum;
+ 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))
return;
-
+
/* Swap Ethernet source and destination addresses */
swap_mac_addresses(packet);
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;
if(type == ICMP6_PACKET_TOO_BIG)
icmp6.icmp6_mtu = htonl(pseudo.length);
-
+
if(pseudo.length >= IP_MSS - ip6_size - icmp6_size)
pseudo.length = IP_MSS - ip6_size - icmp6_size;
-
+
/* Copy first part of original contents to ICMP message */
-
+
memmove(packet->data + ether_size + ip6_size + icmp6_size, packet->data + ether_size, pseudo.length);
/* Fill in IPv6 header */
-
+
ip6.ip6_flow = htonl(0x60000000UL);
ip6.ip6_plen = htons(icmp6_size + pseudo.length);
ip6.ip6_nxt = IPPROTO_ICMPV6;
ip6.ip6_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);
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);
}
return route_ipv6_unreachable(source, packet, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
-
+
if(via == source) {
logger(DEBUG_TRAFFIC, 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, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADMIN);
}
clamp_mss(source, via, packet);
-
+
send_packet(subnet->owner, packet);
}
bool has_opt;
struct {
- struct in6_addr ip6_src; /* source address */
- struct in6_addr ip6_dst; /* destination address */
+ struct in6_addr ip6_src;
+ struct in6_addr ip6_dst;
uint32_t length;
uint32_t next;
} pseudo;
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) {
logger(DEBUG_TRAFFIC, LOG_WARNING, "Got neighbor solicitation request from %s (%s) while in router mode!", source->name, source->hostname);
return;
/* Check if it is for our own subnet */
if(subnet->owner == myself)
- return; /* silently ignore */
+ return; /* silently ignore */
/* 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 */
+ 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 */
/* Check if it is for our own subnet */
if(subnet->owner == myself)
- return; /* silently ignore */
+ return; /* silently ignore */
- memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN); /* copy destination address */
- packet->data[ETH_ALEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */
+ 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 */
if(directonly && subnet->owner != via)
return;
-
+
if(via && packet->len > via->mtu && via != myself) {
logger(DEBUG_TRAFFIC, LOG_INFO, "Packet for %s (%s) length %d larger than MTU %d", subnet->owner->name, subnet->owner->hostname, packet->len, via->mtu);
uint16_t type = packet->data[12] << 8 | packet->data[13];
}
clamp_mss(source, via, packet);
-
+
send_packet(subnet->owner, packet);
}
if(!do_decrement_ttl(source, packet))
return;
+ uint16_t type = packet->data[12] << 8 | packet->data[13];
+
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;
-
- case ETH_P_IPV6:
- route_ipv6(source, packet);
- break;
-
- default:
- logger(DEBUG_TRAFFIC, LOG_WARNING, "Cannot route packet from %s (%s): unknown type %hx", source->name, source->hostname, type);
- break;
- }
+ switch (type) {
+ case ETH_P_ARP:
+ route_arp(source, packet);
+ break;
+
+ case ETH_P_IP:
+ route_ipv4(source, packet);
+ break;
+
+ case ETH_P_IPV6:
+ route_ipv6(source, packet);
+ break;
+
+ default:
+ logger(DEBUG_TRAFFIC, LOG_WARNING, "Cannot route packet from %s (%s): unknown type %hx", source->name, source->hostname, type);
+ break;
}
break;