/* Find TCP header */
int start = ether_size;
- uint16_t type = packet->data[12] << 8 | packet->data[13];
+ uint16_t type = DATA(packet)[12] << 8 | DATA(packet)[13];
if(type == ETH_P_8021Q) {
start += 4;
- type = packet->data[16] << 8 | packet->data[17];
+ type = DATA(packet)[16] << 8 | DATA(packet)[17];
}
- if(type == ETH_P_IP && packet->data[start + 9] == 6)
- start += (packet->data[start] & 0xf) * 4;
- else if(type == ETH_P_IPV6 && packet->data[start + 6] == 6)
+ if(type == ETH_P_IP && DATA(packet)[start + 9] == 6)
+ start += (DATA(packet)[start] & 0xf) * 4;
+ else if(type == ETH_P_IPV6 && DATA(packet)[start + 6] == 6)
start += 40;
else
return;
return;
/* Use data offset field to calculate length of options field */
- int len = ((packet->data[start + 12] >> 4) - 5) * 4;
+ int len = ((DATA(packet)[start + 12] >> 4) - 5) * 4;
if(packet->len < start + 20 + len)
return;
/* Search for MSS option header */
for(int i = 0; i < len;) {
- if(packet->data[start + 20 + i] == 0)
+ if(DATA(packet)[start + 20 + i] == 0)
break;
- if(packet->data[start + 20 + i] == 1) {
+ if(DATA(packet)[start + 20 + i] == 1) {
i++;
continue;
}
- if(i > len - 2 || i > len - packet->data[start + 21 + i])
+ if(i > len - 2 || i > len - DATA(packet)[start + 21 + i])
break;
- if(packet->data[start + 20 + i] != 2) {
- if(packet->data[start + 21 + i] < 2)
+ if(DATA(packet)[start + 20 + i] != 2) {
+ if(DATA(packet)[start + 21 + i] < 2)
break;
- i += packet->data[start + 21 + i];
+ i += DATA(packet)[start + 21 + i];
continue;
}
- if(packet->data[start + 21] != 4)
+ if(DATA(packet)[start + 21] != 4)
break;
/* Found it */
- uint16_t oldmss = packet->data[start + 22 + i] << 8 | packet->data[start + 23 + i];
+ uint16_t oldmss = DATA(packet)[start + 22 + i] << 8 | DATA(packet)[start + 23 + i];
uint16_t newmss = mtu - start - 20;
- uint16_t csum = packet->data[start + 16] << 8 | packet->data[start + 17];
+ uint32_t csum = DATA(packet)[start + 16] << 8 | DATA(packet)[start + 17];
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 */
- packet->data[start + 22 + i] = newmss >> 8;
- packet->data[start + 23 + i] = newmss & 0xff;
+ DATA(packet)[start + 22 + i] = newmss >> 8;
+ DATA(packet)[start + 23 + i] = newmss & 0xff;
csum ^= 0xffff;
- csum -= oldmss;
+ csum += oldmss ^ 0xffff;
csum += newmss;
+ csum = (csum & 0xffff) + (csum >> 16);
+ csum += csum >> 16;
csum ^= 0xffff;
- packet->data[start + 16] = csum >> 8;
- packet->data[start + 17] = csum & 0xff;
+ DATA(packet)[start + 16] = csum >> 8;
+ DATA(packet)[start + 17] = csum;
break;
}
}
static void swap_mac_addresses(vpn_packet_t *packet) {
mac_t tmp;
- memcpy(&tmp, &packet->data[0], sizeof tmp);
- memcpy(&packet->data[0], &packet->data[6], sizeof tmp);
- memcpy(&packet->data[6], &tmp, sizeof tmp);
+ memcpy(&tmp, &DATA(packet)[0], sizeof tmp);
+ memcpy(&DATA(packet)[0], &DATA(packet)[6], sizeof tmp);
+ memcpy(&DATA(packet)[6], &tmp, sizeof tmp);
}
static void age_subnets(void *data) {
struct in_addr ip_src;
struct in_addr ip_dst;
uint32_t oldlen;
+ int sockfd;
if(ratelimit(3))
return;
/* Copy headers from packet into properly aligned structs on the stack */
- memcpy(&ip, packet->data + ether_size, ip_size);
+ memcpy(&ip, DATA(packet) + 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 */
+
+ sockfd = socket(AF_INET, SOCK_DGRAM, 0);
+ if (sockfd != -1) {
+ struct sockaddr_in addr;
+ memset(&addr, 0, sizeof(addr));
+ addr.sin_family = AF_INET;
+ addr.sin_addr = ip.ip_src;
+ if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) {
+ memset(&addr, 0, sizeof(addr));
+ addr.sin_family = AF_INET;
+ socklen_t addrlen = sizeof(addr);
+ if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) {
+ ip_dst = addr.sin_addr;
+ }
+ }
+ close(sockfd);
+ }
+
oldlen = packet->len - ether_size;
if(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
/* Copy first part of original contents to ICMP message */
- memmove(packet->data + ether_size + ip_size + icmp_size, packet->data + ether_size, oldlen);
+ memmove(DATA(packet) + ether_size + ip_size + icmp_size, DATA(packet) + ether_size, oldlen);
/* Fill in IPv4 header */
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);
+ icmp.icmp_cksum = inet_checksum(DATA(packet) + ether_size + ip_size + icmp_size, oldlen, icmp.icmp_cksum);
/* Copy structs on stack back to packet */
- memcpy(packet->data + ether_size, &ip, ip_size);
- memcpy(packet->data + ether_size + ip_size, &icmp, icmp_size);
+ memcpy(DATA(packet) + ether_size, &ip, ip_size);
+ memcpy(DATA(packet) + ether_size + ip_size, &icmp, icmp_size);
packet->len = ether_size + ip_size + icmp_size + oldlen;
uint8_t *offset;
uint16_t ip_off, origf;
- memcpy(&ip, packet->data + ether_size, ip_size);
+ memcpy(&ip, DATA(packet) + ether_size, ip_size);
fragment.priority = packet->priority;
+ fragment.offset = DEFAULT_PACKET_OFFSET;
if(ip.ip_hl != ip_size / 4)
return;
logger(DEBUG_TRAFFIC, LOG_INFO, "Fragmenting packet of %d bytes to %s (%s)", packet->len, dest->name, dest->hostname);
- offset = packet->data + ether_size + ip_size;
+ offset = DATA(packet) + ether_size + ip_size;
maxlen = (dest->mtu - ether_size - ip_size) & ~0x7;
ip_off = ntohs(ip.ip_off);
origf = ip_off & ~IP_OFFMASK;
while(todo) {
len = todo > maxlen ? maxlen : todo;
- memcpy(fragment.data + ether_size + ip_size, offset, len);
+ memcpy(DATA(&fragment) + ether_size + ip_size, offset, len);
todo -= len;
offset += len;
ip.ip_off = htons(ip_off | origf | (todo ? IP_MF : 0));
ip.ip_sum = 0;
ip.ip_sum = inet_checksum(&ip, ip_size, ~0);
- memcpy(fragment.data, packet->data, ether_size);
- memcpy(fragment.data + ether_size, &ip, ip_size);
+ memcpy(DATA(&fragment), DATA(packet), ether_size);
+ memcpy(DATA(&fragment) + ether_size, &ip, ip_size);
fragment.len = ether_size + ip_size + len;
send_packet(dest, &fragment);
node_t *via;
ipv4_t dest;
- memcpy(&dest, &packet->data[30], sizeof dest);
+ memcpy(&dest, &DATA(packet)[30], sizeof dest);
subnet = lookup_subnet_ipv4(&dest);
if(!subnet) {
return route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_NET_ANO);
if(priorityinheritance)
- packet->priority = packet->data[15];
+ packet->priority = DATA(packet)[15];
via = (subnet->owner->via == myself) ? subnet->owner->nexthop : subnet->owner->via;
if(via && packet->len > MAX(via->mtu, 590) && 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);
- if(packet->data[20] & 0x40) {
+ if(DATA(packet)[20] & 0x40) {
packet->len = MAX(via->mtu, 590);
route_ipv4_unreachable(source, packet, ether_size, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED);
} else {
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;
+ int sockfd;
struct {
struct in6_addr ip6_src; /* source address */
/* Copy headers from packet to structs on the stack */
- memcpy(&ip6, packet->data + ether_size, ip6_size);
+ memcpy(&ip6, DATA(packet) + 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 */
+
+ sockfd = socket(AF_INET6, SOCK_DGRAM, 0);
+ if (sockfd != -1) {
+ struct sockaddr_in6 addr;
+ memset(&addr, 0, sizeof(addr));
+ addr.sin6_family = AF_INET6;
+ addr.sin6_addr = ip6.ip6_src;
+ if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) {
+ memset(&addr, 0, sizeof(addr));
+ addr.sin6_family = AF_INET6;
+ socklen_t addrlen = sizeof(addr);
+ if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) {
+ pseudo.ip6_src = addr.sin6_addr;
+ }
+ }
+ close(sockfd);
+ }
+
pseudo.length = packet->len - ether_size;
if(type == ICMP6_PACKET_TOO_BIG)
/* Copy first part of original contents to ICMP message */
- memmove(packet->data + ether_size + ip6_size + icmp6_size, packet->data + ether_size, pseudo.length);
+ memmove(DATA(packet) + ether_size + ip6_size + icmp6_size, DATA(packet) + ether_size, pseudo.length);
/* Fill in IPv6 header */
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);
+ checksum = inet_checksum(DATA(packet) + 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);
+ memcpy(DATA(packet) + ether_size, &ip6, ip6_size);
+ memcpy(DATA(packet) + ether_size + ip6_size, &icmp6, icmp6_size);
packet->len = ether_size + ip6_size + ntohl(pseudo.length);
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) {
+ if(DATA(packet)[20] == IPPROTO_ICMPV6 && checklength(source, packet, ether_size + ip6_size + icmp6_size) && DATA(packet)[54] == ND_NEIGHBOR_SOLICIT) {
route_neighborsol(source, packet);
return;
}
node_t *via;
ipv6_t dest;
- memcpy(&dest, &packet->data[38], sizeof dest);
+ memcpy(&dest, &DATA(packet)[38], sizeof dest);
subnet = lookup_subnet_ipv6(&dest);
if(!subnet) {
/* Copy headers from packet to structs on the stack */
- memcpy(&ip6, packet->data + ether_size, ip6_size);
- memcpy(&ns, packet->data + ether_size + ip6_size, ns_size);
+ memcpy(&ip6, DATA(packet) + ether_size, ip6_size);
+ memcpy(&ns, DATA(packet) + ether_size + ip6_size, ns_size);
if(has_opt)
- memcpy(&opt, packet->data + ether_size + ip6_size + ns_size, opt_size);
+ memcpy(&opt, DATA(packet) + ether_size + ip6_size + ns_size, opt_size);
/* First, snatch the source address from the neighbor solicitation packet */
if(overwrite_mac)
- memcpy(mymac.x, packet->data + ETH_ALEN, ETH_ALEN);
+ memcpy(mymac.x, DATA(packet) + ETH_ALEN, ETH_ALEN);
/* Check if this is a valid neighbor solicitation request */
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);
+ checksum = inet_checksum(DATA(packet) + ether_size + ip6_size + ns_size + opt_size, ETH_ALEN, checksum);
}
if(checksum) {
/* 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(DATA(packet), DATA(packet) + ETH_ALEN, ETH_ALEN); /* copy destination address */
+ DATA(packet)[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_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(DATA(packet) + ether_size + ip6_size + ns_size + opt_size, DATA(packet) + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */
ns.nd_ns_cksum = 0;
ns.nd_ns_type = ND_NEIGHBOR_ADVERT;
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);
+ checksum = inet_checksum(DATA(packet) + ether_size + ip6_size + ns_size + opt_size, ETH_ALEN, checksum);
}
ns.nd_ns_hdr.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, &ns, ns_size);
+ memcpy(DATA(packet) + ether_size, &ip6, ip6_size);
+ memcpy(DATA(packet) + ether_size + ip6_size, &ns, ns_size);
if(has_opt)
- memcpy(packet->data + ether_size + ip6_size + ns_size, &opt, opt_size);
+ memcpy(DATA(packet) + ether_size + ip6_size + ns_size, &opt, opt_size);
send_packet(source, packet);
}
/* First, snatch the source address from the ARP packet */
if(overwrite_mac)
- memcpy(mymac.x, packet->data + ETH_ALEN, ETH_ALEN);
+ memcpy(mymac.x, DATA(packet) + ETH_ALEN, ETH_ALEN);
/* Copy headers from packet to structs on the stack */
- memcpy(&arp, packet->data + ether_size, arp_size);
+ memcpy(&arp, DATA(packet) + ether_size, arp_size);
/* Check if this is a valid ARP request */
if(subnet->owner == myself)
return; /* silently ignore */
- memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN); /* copy destination address */
- packet->data[ETH_ALEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */
-
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_sha, DATA(packet) + ETH_ALEN, ETH_ALEN); /* set source hard/proto addr */
+ arp.arp_sha[ETH_ALEN - 1] ^= 0xFF; /* for consistency with route_packet() */
arp.arp_op = htons(ARPOP_REPLY);
/* Copy structs on stack back to packet */
- memcpy(packet->data + ether_size, &arp, arp_size);
+ memcpy(DATA(packet) + ether_size, &arp, arp_size);
send_packet(source, packet);
}
if(source == myself) {
mac_t src;
- memcpy(&src, &packet->data[6], sizeof src);
+ memcpy(&src, &DATA(packet)[6], sizeof src);
learn_mac(&src);
}
/* Lookup destination address */
- memcpy(&dest, &packet->data[0], sizeof dest);
+ memcpy(&dest, &DATA(packet)[0], sizeof dest);
subnet = lookup_subnet_mac(NULL, &dest);
if(!subnet || !subnet->owner) {
if(forwarding_mode == FMODE_OFF && source != myself && subnet->owner != myself)
return;
- uint16_t type = packet->data[12] << 8 | packet->data[13];
+ uint16_t type = DATA(packet)[12] << 8 | DATA(packet)[13];
if(priorityinheritance && type == ETH_P_IP && packet->len >= ether_size + ip_size)
- packet->priority = packet->data[15];
+ packet->priority = DATA(packet)[15];
// Handle packets larger than PMTU
length_t ethlen = 14;
if(type == ETH_P_8021Q) {
- type = packet->data[16] << 8 | packet->data[17];
+ type = DATA(packet)[16] << 8 | DATA(packet)[17];
ethlen += 4;
}
if(type == ETH_P_IP && packet->len > 576 + ethlen) {
- if(packet->data[6 + ethlen] & 0x40) {
+ if(DATA(packet)[6 + ethlen] & 0x40) {
packet->len = via->mtu;
route_ipv4_unreachable(source, packet, ethlen, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED);
} else {
len = c->outmaclength;
if(send_request(c, "%d %d %d", CONTROL, REQ_PCAP, len))
- send_meta(c, (char *)packet->data, len);
+ send_meta(c, (char *)DATA(packet), len);
}
}
static bool do_decrement_ttl(node_t *source, vpn_packet_t *packet) {
- uint16_t type = packet->data[12] << 8 | packet->data[13];
+ uint16_t type = DATA(packet)[12] << 8 | DATA(packet)[13];
length_t ethlen = ether_size;
if(type == ETH_P_8021Q) {
- type = packet->data[16] << 8 | packet->data[17];
+ type = DATA(packet)[16] << 8 | DATA(packet)[17];
ethlen += 4;
}
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)
+ if(DATA(packet)[ethlen + 8] <= 1) {
+ if(DATA(packet)[ethlen + 11] != IPPROTO_ICMP || DATA(packet)[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];
+ uint16_t old = DATA(packet)[ethlen + 8] << 8 | DATA(packet)[ethlen + 9];
+ DATA(packet)[ethlen + 8]--;
+ uint16_t new = DATA(packet)[ethlen + 8] << 8 | DATA(packet)[ethlen + 9];
- uint32_t checksum = packet->data[ethlen + 10] << 8 | packet->data[ethlen + 11];
+ uint32_t checksum = DATA(packet)[ethlen + 10] << 8 | DATA(packet)[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;
+ DATA(packet)[ethlen + 10] = checksum >> 8;
+ DATA(packet)[ethlen + 11] = checksum & 0xff;
return true;
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)
+ if(DATA(packet)[ethlen + 7] <= 1) {
+ if(DATA(packet)[ethlen + 6] != IPPROTO_ICMPV6 || DATA(packet)[ethlen + 40] != ICMP6_TIME_EXCEEDED)
route_ipv6_unreachable(source, packet, ethlen, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT);
return false;
}
- packet->data[ethlen + 7]--;
+ DATA(packet)[ethlen + 7]--;
return true;
if(!do_decrement_ttl(source, packet))
return;
- uint16_t type = packet->data[12] << 8 | packet->data[13];
+ uint16_t type = DATA(packet)[12] << 8 | DATA(packet)[13];
switch (routing_mode) {
case RMODE_ROUTER: