- Speed up checksumming
- If a destination is not found in the subnet list or the destination node is unreachable, respond with an appropiate ICMP message.
This commit is contained in:
Guus Sliepen
parent
9792ba2cac
commit
7d21a8d1c7
1 changed files with 181 additions and 23 deletions
204
src/route.c
204
src/route.c
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@ -17,7 +17,7 @@
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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$Id: route.c,v 1.1.2.46 2002/09/09 22:33:16 guus Exp $
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$Id: route.c,v 1.1.2.47 2003/03/29 21:51:21 guus Exp $
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*/
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#include "config.h"
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@ -36,6 +36,8 @@
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#ifdef HAVE_NETINET_IN_SYSTM_H
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#include <netinet/in_systm.h>
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#endif
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#include <netinet/ip.h>
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#include <netinet/ip_icmp.h>
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#include <netinet/ip6.h>
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#include <netinet/icmp6.h>
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#include <netinet/if_ether.h>
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@ -67,6 +69,34 @@ int priorityinheritance = 0;
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int macexpire = 600;
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subnet_t mymac;
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/* RFC 1071 */
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uint16_t inet_checksum(void *data, int len, uint16_t prevsum)
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{
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uint16_t *p = data;
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uint32_t checksum = prevsum ^ 0xFFFF;
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len /= 2;
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while(len--)
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checksum += *p++;
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while(checksum >> 16)
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checksum = (checksum & 0xFFFF) + (checksum >> 16);
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return ~checksum;
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}
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int ratelimit(void) {
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static time_t lasttime = 0;
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if(lasttime == now)
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return 1;
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lasttime = now;
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return 0;
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}
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void learn_mac(mac_t *address)
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{
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subnet_t *subnet;
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@ -151,6 +181,67 @@ node_t *route_mac(vpn_packet_t *packet)
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return NULL;
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}
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/* RFC 792 */
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void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code)
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{
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struct ip *hdr;
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struct icmp *icmp;
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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())
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return;
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cp();
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hdr = (struct ip *)(packet->data + 14);
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icmp = (struct icmp *)(packet->data + 14 + 20);
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/* Remember original source and destination */
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memcpy(&ip_src, &hdr->ip_src, 4);
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memcpy(&ip_dst, &hdr->ip_dst, 4);
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oldlen = packet->len - 14;
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if(oldlen >= IP_MSS - sizeof(*hdr) - sizeof(struct icmphdr))
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oldlen = IP_MSS - sizeof(*hdr) - sizeof(struct icmphdr);
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/* Copy first part of original contents to ICMP message */
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memmove(&icmp->icmp_ip, hdr, oldlen);
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/* Fill in IPv4 header */
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hdr->ip_v = 4;
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hdr->ip_hl = sizeof(*hdr) / 4;
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hdr->ip_tos = 0;
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hdr->ip_len = htons(20 + 8 + oldlen);
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hdr->ip_id = 0;
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hdr->ip_off = 0;
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hdr->ip_ttl = 255;
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hdr->ip_p = IPPROTO_ICMP;
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hdr->ip_sum = 0;
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memcpy(&hdr->ip_src, &ip_dst, 4);
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memcpy(&hdr->ip_dst, &ip_src, 4);
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hdr->ip_sum = inet_checksum(hdr, 20, ~0);
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/* Fill in ICMP header */
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icmp->icmp_type = ICMP_DEST_UNREACH;
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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, 8 + oldlen, ~0);
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packet->len = 14 + 20 + 8 + oldlen;
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write_packet(packet);
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}
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node_t *route_ipv4(vpn_packet_t *packet)
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{
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subnet_t *subnet;
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@ -169,12 +260,86 @@ node_t *route_ipv4(vpn_packet_t *packet)
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packet->data[33]);
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}
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route_ipv4_unreachable(packet, ICMP_NET_UNKNOWN);
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return NULL;
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}
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if(!subnet->owner->status.reachable)
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route_ipv4_unreachable(packet, ICMP_NET_UNREACH);
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return subnet->owner;
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}
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/* RFC 2463 */
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void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code)
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{
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struct ip6_hdr *hdr;
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struct icmp6_hdr *icmp;
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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())
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return;
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cp();
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hdr = (struct ip6_hdr *)(packet->data + 14);
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icmp = (struct icmp6_hdr *)(packet->data + 14 + sizeof(*hdr));
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/* Remember original source and destination */
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memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
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memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
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pseudo.length = ntohs(hdr->ip6_plen) + sizeof(*hdr);
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if(pseudo.length >= IP_MSS - sizeof(*hdr) - sizeof(*icmp))
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pseudo.length = IP_MSS - sizeof(*hdr) - sizeof(*icmp);
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/* Copy first part of original contents to ICMP message */
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memmove(((char *)icmp) + sizeof(*icmp), hdr, pseudo.length);
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/* Fill in IPv6 header */
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hdr->ip6_flow = htonl(0x60000000UL);
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hdr->ip6_plen = htons(sizeof(*icmp) + pseudo.length);
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hdr->ip6_nxt = IPPROTO_ICMPV6;
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hdr->ip6_hlim = 255;
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memcpy(&hdr->ip6_dst, &pseudo.ip6_src, 16);
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memcpy(&hdr->ip6_src, &pseudo.ip6_dst, 16);
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/* Fill in ICMP header */
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icmp->icmp6_type = ICMP6_DST_UNREACH;
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icmp->icmp6_code = code;
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icmp->icmp6_cksum = 0;
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/* Create pseudo header */
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memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
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memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
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pseudo.length = htonl(sizeof(*icmp) + 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(icmp, ntohl(pseudo.length), checksum);
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icmp->icmp6_cksum = checksum;
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packet->len = 14 + sizeof(*hdr) + ntohl(pseudo.length);
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write_packet(packet);
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}
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node_t *route_ipv6(vpn_packet_t *packet)
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{
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subnet_t *subnet;
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@ -195,25 +360,18 @@ node_t *route_ipv6(vpn_packet_t *packet)
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ntohs(*(uint16_t *) & packet->data[50]),
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ntohs(*(uint16_t *) & packet->data[52]));
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}
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route_ipv6_unreachable(packet, ICMP6_DST_UNREACH_ADDR);
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return NULL;
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}
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if(!subnet->owner->status.reachable)
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route_ipv6_unreachable(packet, ICMP6_DST_UNREACH_NOROUTE);
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return subnet->owner;
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}
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uint16_t inet_checksum(uint16_t *data, int len, uint16_t prevsum)
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{
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uint32_t checksum = prevsum ^ 0xFFFF;
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while(len--)
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checksum += ntohs(*data++);
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while(checksum >> 16)
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checksum = (checksum & 0xFFFF) + (checksum >> 16);
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return checksum ^ 0xFFFF;
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}
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/* RFC 2461 */
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void route_neighborsol(vpn_packet_t *packet)
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{
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@ -227,7 +385,7 @@ void route_neighborsol(vpn_packet_t *packet)
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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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uint8_t junk[4];
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uint32_t next;
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} pseudo;
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cp();
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@ -255,13 +413,12 @@ void route_neighborsol(vpn_packet_t *packet)
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memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
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memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
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pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6);
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pseudo.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0;
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pseudo.junk[3] = IPPROTO_ICMPV6;
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pseudo.next = htonl(IPPROTO_ICMPV6);
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/* Generate checksum */
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checksum = inet_checksum((uint16_t *) & pseudo, sizeof(pseudo) / 2, ~0);
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checksum = inet_checksum((uint16_t *) ns, sizeof(*ns) / 2 + 4, checksum);
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checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
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checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum);
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if(checksum) {
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if(debug_lvl >= DEBUG_TRAFFIC)
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@ -317,19 +474,20 @@ void route_neighborsol(vpn_packet_t *packet)
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memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
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memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
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pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6);
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pseudo.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0;
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pseudo.junk[3] = IPPROTO_ICMPV6;
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pseudo.next = htonl(IPPROTO_ICMPV6);
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/* Generate checksum */
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checksum = inet_checksum((uint16_t *) & pseudo, sizeof(pseudo) / 2, ~0);
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checksum = inet_checksum((uint16_t *) ns, sizeof(*ns) / 2 + 4, checksum);
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checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0);
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checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum);
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ns->nd_ns_hdr.icmp6_cksum = htons(checksum);
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ns->nd_ns_hdr.icmp6_cksum = checksum;
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write_packet(packet);
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}
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/* RFC 826 */
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void route_arp(vpn_packet_t *packet)
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{
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struct ether_arp *arp;
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