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https://code.semirocket.science/wrapsix
synced 2024-09-19 23:11:04 +03:00
Recognising NDP packets and packets to be wrapped
Cleaned the code a little bit
This commit is contained in:
xHire
parent
4bc68edce5
commit
322eeabefb
4
TODO
4
TODO
@ -31,4 +31,6 @@
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- create some home web page (may be a wiki?)
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== PostFinal stage ==
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- rewrite to C :c)
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- optimise
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- translation_ip.c -> don't translate IPv6 to IPv4 through a string
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- rewrite DNS wrapping resolver into C
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@ -3,39 +3,39 @@
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void process_packet6(u_char *args, const struct pcap_pkthdr *header, const u_char *packet)
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{
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static int count = 1; /* packet counter */
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const struct s_ethernet *ethernet; /* the ethernet header */
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const struct s_ip6 *ip; /* the IP header */
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const unsigned char *payload; /* packet payload */
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/* declare pointers to packet headers */
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const struct s_ethernet *ethernet; /* The ethernet header [1] */
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const struct s_ip6 *ip; /* The IP header */
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const unsigned char *payload; /* Packet payload */
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printf("\nPacket number %d:\n", count);
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count++;
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struct in6_addr ip6addr_wrapsix;
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struct in6_addr ip6addr_ndp_multicast;
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/* define ethernet header */
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ethernet = (struct s_ethernet*) (packet);
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/* define/compute ip header offset */
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/* define/compute IP header offset */
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ip = (struct s_ip6*) (packet + SIZE_ETHERNET);
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/* define/compute IP payload offset */
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payload = packet + SIZE_ETHERNET + SIZE_IP6;
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/* print source and destination IP addresses */
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char ip6addr[INET6_ADDRSTRLEN];
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inet_ntop(AF_INET6, &ip->ip_src, ip6addr, sizeof(ip6addr));
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printf(" From: %s\n", ip6addr);
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/* keep the following line as the last one inet_ntop! */
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inet_ntop(AF_INET6, &ip->ip_dest, ip6addr, sizeof(ip6addr));
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printf(" To: %s\n", ip6addr);
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/* check if this packet is ours - hardcoded for now */
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char wsaddr[INET6_ADDRSTRLEN] = "fc00:1::4d4b:4c03";
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if (strcmp(wsaddr, ip6addr) != 0) {
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printf("==> This packet is not ours! <==\n");
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/* check if this packet is ours - partially hardcoded for now */
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inet_pton(AF_INET6, "fc00:1::", &ip6addr_wrapsix);
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inet_pton(AF_INET6, "ff02::1:ff00:0", &ip6addr_ndp_multicast);
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/* check for our prefix || NDP */
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if (memcmp(&ip6addr_wrapsix, &ip->ip_dest, 12) != 0
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&& memcmp(&ip6addr_ndp_multicast, &ip->ip_dest, 13) != 0) {
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printf("==> This packet is not ours! And it's not NDP! <==\n");
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return;
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}
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/* DEBUG: print source and destination IP addresses */
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char ip6addr[INET6_ADDRSTRLEN];
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inet_ntop(AF_INET6, &ip->ip_src, ip6addr, sizeof(ip6addr));
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printf("\n From: %s\n", ip6addr);
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inet_ntop(AF_INET6, &ip->ip_dest, ip6addr, sizeof(ip6addr));
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printf(" To: %s\n", ip6addr);
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/* determine protocol */
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switch (ip->next_header) {
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case IPPROTO_TCP:
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@ -56,83 +56,82 @@ void process_packet6(u_char *args, const struct pcap_pkthdr *header, const u_cha
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return;
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}
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void process_icmp6(struct s_ip6 *ip, const unsigned char *payload)
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void process_icmp6(const struct s_ip6 *ip, const unsigned char *payload)
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{
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struct s_icmp *icmp;
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struct in_addr ip4_addr;
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unsigned char *icmp_data;
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const unsigned char *icmp_data;
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unsigned char *icmp_packet;
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int packet_size;
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/* extract the ICMP header */
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/* define ICMP header */
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icmp = (struct s_icmp *) (payload);
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icmp_data = (unsigned char *) (payload + sizeof(icmp));
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/* define/compute ICMP data offset */
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icmp_data = (unsigned char *) (payload + sizeof(struct s_icmp));
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/* the checksum has to be zeros before we have data for its computation */
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icmp->checksum = 0;
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/* create one big ICMP packet */
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packet_size = htons(ip->len);
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icmp_packet = (unsigned char *) malloc(packet_size);
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if (icmp_packet == NULL) {
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fprintf(stderr, "Fatal error! Lack of free memory!\n");
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exit(EXIT_FAILURE);
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}
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/* decide what type of ICMP we have */
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switch (icmp->type) {
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/* NDP */
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case ICMP6_NDP_NS:
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printf(" ICMP: [NDP] Neighbor Solicitation\n");
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break;
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case ICMP6_NDP_NA:
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printf(" ICMP: [NDP] Neighbor Advertisement\n");
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break;
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case ICMP6_NDP_RS:
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printf(" ICMP: [NDP] Router Solicitation\n");
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break;
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case ICMP6_NDP_RA:
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printf(" ICMP: [NDP] Router Advertisement\n");
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break;
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case ICMP6_NDP_RM:
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printf(" ICMP: [NDP] Redirect Message\n");
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return;
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break;
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/* ping */
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case ICMP6_ECHO_REQUEST:
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printf(" ICMP: Echo Request\n");
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packet_size = htons(ip->len);
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icmp_packet = (unsigned char *) malloc(packet_size);
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if (icmp_packet == NULL) {
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fprintf(stderr, "Fatal error! Lack of free memory!\n");
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exit(EXIT_FAILURE);
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}
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/* DEBUG */
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struct s_icmp_ping *icmp_ping = (struct s_icmp_ping *) icmp_data;
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icmp->type = ICMP4_ECHO_REQUEST;
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icmp->code = 0;
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icmp->checksum = 0;
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printf("[id;seq]:[0x%x;0x%x]\n", htons(icmp_ping->id), htons(icmp_ping->seq));
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memcpy(icmp_packet, icmp, sizeof(struct s_icmp));
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memcpy(icmp_packet + sizeof(struct s_icmp), icmp_data, packet_size - sizeof(struct s_icmp));
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// compute the checksum :c)
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icmp->checksum = checksum(icmp_packet, packet_size);
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// copy this structure again - because of the checksum
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memcpy(icmp_packet, icmp, sizeof(struct s_icmp));
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/* fill into the header known statements */
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icmp->type = ICMP4_ECHO_REQUEST;
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icmp->code = 0;
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break;
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case ICMP6_ECHO_REPLY:
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printf(" ICMP: Echo Reply\n");
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return;
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break;
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/* nothing interesting */
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default:
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printf(" ICMP: unknown: %d/0x%x\n", icmp->type, icmp->type);
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return;
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break;
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}
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/* where to send this ICMP */
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/* copy data into the packet */
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memcpy(icmp_packet, icmp, sizeof(struct s_icmp));
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memcpy(icmp_packet + sizeof(struct s_icmp), icmp_data,
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packet_size - sizeof(struct s_icmp));
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/* compute the checksum */
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icmp->checksum = checksum(icmp_packet, packet_size);
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/* copy this structure again - because of the checksum */
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memcpy(icmp_packet, icmp, sizeof(struct s_icmp));
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/* decide where to send this ICMP */
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ip4_addr = ipaddr_6to4((struct in6_addr) ip->ip_dest);
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printf(" Send to: %s\n", inet_ntoa(ip4_addr));
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/* send */
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send_there(ip4_addr, ip->hop_limit, IPPROTO_ICMP, icmp_packet, packet_size);
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/* free allocated memory */
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free(icmp_packet);
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icmp_packet = NULL;
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@ -1,14 +1,14 @@
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#include "wrapper.h"
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#include "translate_ip.h"
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struct in_addr ipaddr_6to4(struct in6_addr ip6_addr)
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struct in_addr ipaddr_6to4(const struct in6_addr ip6_addr)
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{
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struct ip6addr_ip4part *addr;
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struct in_addr ip4_addr;
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char ip4_str[15];
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/* "parse" the IPv6 addres */
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addr = (struct ip6addr_ip4part *)(&ip6_addr);
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/* define the IPv6 address */
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addr = (struct ip6addr_ip4part *) (&ip6_addr);
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/* build IPv4 address */
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sprintf(ip4_str, "%d.%d.%d.%d", addr->a, addr->b, addr->c, addr->d);
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@ -9,7 +9,7 @@ struct ip6addr_ip4part {
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unsigned char d;
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};
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struct in_addr ipaddr_6to4(struct in6_addr ip6_addr);
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struct in_addr ipaddr_6to4(const struct in6_addr ip6_addr);
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//in6_addr ipaddr_4to6(in_addr ip_addr);
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#endif
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@ -69,6 +69,16 @@ struct s_icmp_ping {
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unsigned short seq; /* 16 b; sequence value for ECHO REPLY */
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};
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/* ICMPv6 - NDP NS structure */
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struct s_icmp_ndp_ns {
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unsigned int zeros; /* 32 b; reserved section */
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struct in6_addr target; /* 128 b; target IP address */
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};
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struct s_icmp_ndp_option {
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unsigned char type; /* 8 b; type of the option */
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unsigned char len; /* 8 b; length of the option (including this header!) */
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};
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/* ICMP types */
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#define ICMP4_ECHO_REQUEST 0x8
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#define ICMP4_ECHO_REPLY 0x0
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@ -84,7 +94,7 @@ struct s_icmp_ping {
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/* Prototypes */
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void process_packet6(u_char *args, const struct pcap_pkthdr *header, const u_char *packet);
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void process_icmp6(struct s_ip6 *ip, const unsigned char *payload);
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void process_icmp6(const struct s_ip6 *ip, const unsigned char *payload);
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void send_there(struct in_addr ip4_addr, unsigned char ttl, unsigned int type, unsigned char *payload, unsigned int paylen);
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