along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: route.c,v 1.1.2.45 2002/09/09 21:25:07 guus Exp $
+ $Id: route.c,v 1.1.2.47 2003/03/29 21:51:21 guus Exp $
*/
#include "config.h"
#ifdef HAVE_NETINET_IN_SYSTM_H
#include <netinet/in_systm.h>
#endif
+#include <netinet/ip.h>
+#include <netinet/ip_icmp.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <netinet/if_ether.h>
int macexpire = 600;
subnet_t mymac;
-void learn_mac(mac_t * address)
+/* RFC 1071 */
+
+uint16_t inet_checksum(void *data, int len, uint16_t prevsum)
+{
+ uint16_t *p = data;
+ uint32_t checksum = prevsum ^ 0xFFFF;
+
+ len /= 2;
+
+ while(len--)
+ checksum += *p++;
+
+ while(checksum >> 16)
+ checksum = (checksum & 0xFFFF) + (checksum >> 16);
+
+ return ~checksum;
+}
+
+int ratelimit(void) {
+ static time_t lasttime = 0;
+
+ if(lasttime == now)
+ return 1;
+
+ lasttime = now;
+ return 0;
+}
+
+void learn_mac(mac_t *address)
{
subnet_t *subnet;
avl_node_t *node;
}
}
-node_t *route_mac(vpn_packet_t * packet)
+node_t *route_mac(vpn_packet_t *packet)
{
subnet_t *subnet;
/* Learn source address */
- learn_mac((mac_t *) (&packet->data[6]));
+ learn_mac((mac_t *)(&packet->data[6]));
/* Lookup destination address */
- subnet = lookup_subnet_mac((mac_t *) (&packet->data[0]));
+ subnet = lookup_subnet_mac((mac_t *)(&packet->data[0]));
if(subnet)
return subnet->owner;
return NULL;
}
-node_t *route_ipv4(vpn_packet_t * packet)
+/* RFC 792 */
+
+void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code)
+{
+ struct ip *hdr;
+ struct icmp *icmp;
+
+ struct in_addr ip_src;
+ struct in_addr ip_dst;
+ uint32_t oldlen;
+
+ if(ratelimit())
+ return;
+
+ cp();
+
+ hdr = (struct ip *)(packet->data + 14);
+ icmp = (struct icmp *)(packet->data + 14 + 20);
+
+ /* Remember original source and destination */
+
+ memcpy(&ip_src, &hdr->ip_src, 4);
+ memcpy(&ip_dst, &hdr->ip_dst, 4);
+ oldlen = packet->len - 14;
+
+ if(oldlen >= IP_MSS - sizeof(*hdr) - sizeof(struct icmphdr))
+ oldlen = IP_MSS - sizeof(*hdr) - sizeof(struct icmphdr);
+
+ /* Copy first part of original contents to ICMP message */
+
+ memmove(&icmp->icmp_ip, hdr, oldlen);
+
+ /* Fill in IPv4 header */
+
+ hdr->ip_v = 4;
+ hdr->ip_hl = sizeof(*hdr) / 4;
+ hdr->ip_tos = 0;
+ hdr->ip_len = htons(20 + 8 + oldlen);
+ hdr->ip_id = 0;
+ hdr->ip_off = 0;
+ hdr->ip_ttl = 255;
+ hdr->ip_p = IPPROTO_ICMP;
+ hdr->ip_sum = 0;
+ memcpy(&hdr->ip_src, &ip_dst, 4);
+ memcpy(&hdr->ip_dst, &ip_src, 4);
+
+ hdr->ip_sum = inet_checksum(hdr, 20, ~0);
+
+ /* Fill in ICMP header */
+
+ icmp->icmp_type = ICMP_DEST_UNREACH;
+ icmp->icmp_code = code;
+ icmp->icmp_cksum = 0;
+
+ icmp->icmp_cksum = inet_checksum(icmp, 8 + oldlen, ~0);
+
+ packet->len = 14 + 20 + 8 + oldlen;
+
+ write_packet(packet);
+}
+
+node_t *route_ipv4(vpn_packet_t *packet)
{
subnet_t *subnet;
packet->data[33]);
}
+ route_ipv4_unreachable(packet, ICMP_NET_UNKNOWN);
return NULL;
}
+
+ if(!subnet->owner->status.reachable)
+ route_ipv4_unreachable(packet, ICMP_NET_UNREACH);
return subnet->owner;
}
-node_t *route_ipv6(vpn_packet_t * packet)
+/* RFC 2463 */
+
+void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code)
+{
+ struct ip6_hdr *hdr;
+ struct icmp6_hdr *icmp;
+ uint16_t checksum;
+
+ struct {
+ struct in6_addr ip6_src; /* source address */
+ struct in6_addr ip6_dst; /* destination address */
+ uint32_t length;
+ uint32_t next;
+ } pseudo;
+
+ if(ratelimit())
+ return;
+
+ cp();
+
+ hdr = (struct ip6_hdr *)(packet->data + 14);
+ icmp = (struct icmp6_hdr *)(packet->data + 14 + sizeof(*hdr));
+
+ /* Remember original source and destination */
+
+ memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
+ memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
+ pseudo.length = ntohs(hdr->ip6_plen) + sizeof(*hdr);
+
+ if(pseudo.length >= IP_MSS - sizeof(*hdr) - sizeof(*icmp))
+ pseudo.length = IP_MSS - sizeof(*hdr) - sizeof(*icmp);
+
+ /* Copy first part of original contents to ICMP message */
+
+ memmove(((char *)icmp) + sizeof(*icmp), hdr, pseudo.length);
+
+ /* Fill in IPv6 header */
+
+ hdr->ip6_flow = htonl(0x60000000UL);
+ hdr->ip6_plen = htons(sizeof(*icmp) + pseudo.length);
+ hdr->ip6_nxt = IPPROTO_ICMPV6;
+ hdr->ip6_hlim = 255;
+ memcpy(&hdr->ip6_dst, &pseudo.ip6_src, 16);
+ memcpy(&hdr->ip6_src, &pseudo.ip6_dst, 16);
+
+ /* Fill in ICMP header */
+
+ icmp->icmp6_type = ICMP6_DST_UNREACH;
+ icmp->icmp6_code = code;
+ icmp->icmp6_cksum = 0;
+
+ /* Create pseudo header */
+
+ memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
+ memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
+ pseudo.length = htonl(sizeof(*icmp) + pseudo.length);
+ pseudo.next = htonl(IPPROTO_ICMPV6);
+
+ /* Generate checksum */
+
+ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
+ checksum = inet_checksum(icmp, ntohl(pseudo.length), checksum);
+
+ icmp->icmp6_cksum = checksum;
+
+ packet->len = 14 + sizeof(*hdr) + ntohl(pseudo.length);
+
+ write_packet(packet);
+}
+
+node_t *route_ipv6(vpn_packet_t *packet)
{
subnet_t *subnet;
ntohs(*(uint16_t *) & packet->data[50]),
ntohs(*(uint16_t *) & packet->data[52]));
}
+ route_ipv6_unreachable(packet, ICMP6_DST_UNREACH_ADDR);
return NULL;
}
+ if(!subnet->owner->status.reachable)
+ route_ipv6_unreachable(packet, ICMP6_DST_UNREACH_NOROUTE);
+
return subnet->owner;
}
-uint16_t inet_checksum(uint16_t * data, int len, uint16_t prevsum)
-{
- uint32_t checksum = prevsum ^ 0xFFFF;
-
- while(len--)
- checksum += ntohs(*data++);
-
- while(checksum >> 16)
- checksum = (checksum & 0xFFFF) + (checksum >> 16);
+/* RFC 2461 */
- return checksum ^ 0xFFFF;
-}
-
-void route_neighborsol(vpn_packet_t * packet)
+void route_neighborsol(vpn_packet_t *packet)
{
struct ip6_hdr *hdr;
struct nd_neighbor_solicit *ns;
struct in6_addr ip6_src; /* source address */
struct in6_addr ip6_dst; /* destination address */
uint32_t length;
- uint8_t junk[4];
+ uint32_t next;
} pseudo;
cp();
- hdr = (struct ip6_hdr *) (packet->data + 14);
- ns = (struct nd_neighbor_solicit *) (packet->data + 14 + sizeof(*hdr));
- opt = (struct nd_opt_hdr *) (packet->data + 14 + sizeof(*hdr) + sizeof(*ns));
+ hdr = (struct ip6_hdr *)(packet->data + 14);
+ ns = (struct nd_neighbor_solicit *)(packet->data + 14 + sizeof(*hdr));
+ opt = (struct nd_opt_hdr *)(packet->data + 14 + sizeof(*hdr) + sizeof(*ns));
/* First, snatch the source address from the neighbor solicitation packet */
memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6);
- pseudo.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0;
- pseudo.junk[3] = IPPROTO_ICMPV6;
+ pseudo.next = htonl(IPPROTO_ICMPV6);
/* Generate checksum */
- checksum = inet_checksum((uint16_t *) & pseudo, sizeof(pseudo) / 2, ~0);
- checksum = inet_checksum((uint16_t *) ns, sizeof(*ns) / 2 + 4, checksum);
+ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
+ checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum);
if(checksum) {
if(debug_lvl >= DEBUG_TRAFFIC)
memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6);
- pseudo.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0;
- pseudo.junk[3] = IPPROTO_ICMPV6;
+ pseudo.next = htonl(IPPROTO_ICMPV6);
/* Generate checksum */
- checksum = inet_checksum((uint16_t *) & pseudo, sizeof(pseudo) / 2, ~0);
- checksum = inet_checksum((uint16_t *) ns, sizeof(*ns) / 2 + 4, checksum);
+ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
+ checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum);
- ns->nd_ns_hdr.icmp6_cksum = htons(checksum);
+ ns->nd_ns_hdr.icmp6_cksum = checksum;
write_packet(packet);
}
-void route_arp(vpn_packet_t * packet)
+/* RFC 826 */
+
+void route_arp(vpn_packet_t *packet)
{
struct ether_arp *arp;
subnet_t *subnet;
Most of the code here is taken from choparp.c by Takamichi Tateoka (tree@mma.club.uec.ac.jp)
*/
- arp = (struct ether_arp *) (packet->data + 14);
+ arp = (struct ether_arp *)(packet->data + 14);
/* Check if this is a valid ARP request */
write_packet(packet);
}
-void route_outgoing(vpn_packet_t * packet)
+void route_outgoing(vpn_packet_t *packet)
{
uint16_t type;
node_t *n = NULL;
switch (routing_mode) {
case RMODE_ROUTER:
- type = ntohs(*((uint16_t *) (&packet->data[12])));
+ type = ntohs(*((uint16_t *)(&packet->data[12])));
switch (type) {
case 0x0800:
n = route_ipv4(packet);
}
}
-void route_incoming(node_t * source, vpn_packet_t * packet)
+void route_incoming(node_t *source, vpn_packet_t *packet)
{
switch (routing_mode) {
case RMODE_ROUTER:
node_t *n = NULL;
uint16_t type;
- type = ntohs(*((uint16_t *) (&packet->data[12])));
+ type = ntohs(*((uint16_t *)(&packet->data[12])));
switch (type) {
case 0x0800:
n = route_ipv4(packet);
{
subnet_t *subnet;
- subnet = lookup_subnet_mac((mac_t *) (&packet->data[0]));
+ subnet = lookup_subnet_mac((mac_t *)(&packet->data[0]));
if(subnet) {
if(subnet->owner == myself)
projects / tinc / blobdiff