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thc-ipv6-lib.c
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/*
* (c) 2019 by van Hauser / THC <[email protected]>
*
* THC IPv6 Attack Library
*
* Functions: see README
*
* The AGPL v3 license applies to this code, see the LICENSE file
*
*/
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <unistd.h>
#include <ctype.h>
/* network */
#include <netpacket/packet.h>
#include <net/if.h>
#include <net/ethernet.h>
#include <linux/if_ether.h>
#include <netinet/in.h>
#include <netinet/ether.h>
#include <signal.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
//#include <linux/if.h>
/* files */
#include <fcntl.h>
#include <sys/ioctl.h>
/* misc */
#include <time.h>
#include <errno.h>
/* libpcap */
#include <pcap.h>
#ifdef _HAVE_SSL
/* libssl */
#include <openssl/evp.h>
#include <openssl/sha.h>
#include <openssl/rsa.h>
#include <openssl/x509.h>
#include <openssl/err.h>
#endif
/* OS specifics */
#if defined(__APPLE__)
#include <libkern/OSByteOrder.h>
#define bswap_16 OSSwapInt16
#define bswap_32 OSSwapInt32
#define bswap_64 OSSwapInt64
#else
#include <byteswap.h>
#endif
#if !defined (SIOCGIFHWADDR)
#include <ifaddrs.h>
#include <net/if_dl.h>
#include <netinet/if_ether.h>
#else
#include <linux/if_ether.h>
#include <linux/netlink.h>
#endif
#include "thc-ipv6.h"
// we need this because the default sockaddr structure does not fit the maximum device name length on linux.
// why linux? why??
struct thcsockaddr {
u_short sa_family; /* address family */
char sa_data[16]; /* up to 16 bytes of direct address */
};
/***********************************************************/
// exported to external via thc-ipv6.h
int debug = 0;
int _thc_ipv6_showerrors = SHOW_LIBRARY_ERRORS;
int do_hdr_size = 0, do_hdr_vlan = 0;
// injection variables
#define _PPPOE_HDR_SIZE 22
#define _6IN4_HDR_SIZE 34
int do_6in4 = 0, do_pppoe = 0, do_hdr_off = 0;
char *do_hdr = NULL, *do_capture = NULL;
// other internal global vars
char default_interface[32] = "eth0";
int thc_socket = -1;
int _thc_ipv6_rawmode = 0;
void thc_ipv6_rawmode(int mode) {
_thc_ipv6_rawmode = mode;
if (mode != 0)
fprintf(stderr, "Warning: raw mode is not working in all tools\n");
}
void thc_ipv6_show_errors(int mode) {
_thc_ipv6_showerrors = mode;
}
unsigned char *thc_ipv6_dummymac() {
char *ptr = malloc(7);
if (ptr == NULL)
return NULL;
memset(ptr, 0xff, 6);
ptr[6] = 0;
return ptr;
}
int thc_pcap_function(char *interface, char *capture, char *function, int promisc, char *opt) {
pcap_t *pcap_link = NULL;
char errbuf[PCAP_ERRBUF_SIZE];
struct bpf_program fcode;
if (thc_socket < 0)
thc_socket = thc_open_ipv6();
if (do_pppoe || do_6in4 || do_hdr_vlan)
promisc = 1;
if (interface == NULL)
interface = default_interface;
if ((pcap_link = pcap_open_live(interface, 65535, promisc, -1, errbuf)) == NULL)
return -1;
if (do_pppoe || do_6in4 || do_hdr_vlan)
pcap_compile(pcap_link, &fcode, do_capture, 1, 0);
else
if (pcap_compile(pcap_link, &fcode, capture, 1, 0) < 0)
return -2;
pcap_setfilter(pcap_link, &fcode);
while(1) {
if (pcap_dispatch(pcap_link, 1, (pcap_handler) function, opt) < 0)
return -3;
usleep(10);
}
return -4; // never reached
}
pcap_t *thc_pcap_init(char *interface, char *capture) {
pcap_t *pcap_link = NULL;
char errbuf[PCAP_ERRBUF_SIZE];
struct bpf_program fcode;
int promisc = 0;
if (thc_socket < 0)
thc_socket = thc_open_ipv6();
if (do_pppoe || do_6in4 || do_hdr_vlan)
promisc = 1;
if (interface == NULL)
interface = default_interface;
if ((pcap_link = pcap_open_live(interface, 65535, promisc, -1, errbuf)) == NULL)
return NULL;
if (do_pppoe || do_6in4 || do_hdr_vlan)
pcap_compile(pcap_link, &fcode, do_capture, 1, 0);
else
if (pcap_compile(pcap_link, &fcode, capture, 1, 0) < 0)
return NULL;
pcap_setfilter(pcap_link, &fcode);
pcap_setnonblock(pcap_link, 1, errbuf);
return pcap_link;
}
pcap_t *thc_pcap_init_promisc(char *interface, unsigned char *capture) {
pcap_t *pcap_link = NULL;
char errbuf[PCAP_ERRBUF_SIZE];
struct bpf_program fcode;
if (thc_socket < 0)
thc_socket = thc_open_ipv6();
if (interface == NULL)
interface = default_interface;
if ((pcap_link = pcap_open_live(interface, 65535, 1, -1, errbuf)) == NULL)
return NULL;
if (do_pppoe || do_6in4 || do_hdr_vlan)
pcap_compile(pcap_link, &fcode, do_capture, 1, 0);
else
if (pcap_compile(pcap_link, &fcode, capture, 1, 0) < 0)
return NULL;
pcap_setfilter(pcap_link, &fcode);
pcap_setnonblock(pcap_link, 1, errbuf);
return pcap_link;
}
int thc_pcap_check(pcap_t * pcap_link, char *function, char *opt) {
if (pcap_link == NULL)
return -1;
return pcap_dispatch(pcap_link, 1, (pcap_handler) function, opt);
}
char *thc_pcap_close(pcap_t * pcap_link) {
if (pcap_link != NULL)
pcap_close(pcap_link);
return NULL;
}
/* wow, ugly, complicated work for something a standard linux library could do as well :-) */
void thc_notation2beauty(unsigned char *ipv6) {
char buf[40], buf2[40] = ":0:0:", *ptr, *ptr2 = NULL;
int i, j, k = 0, l = 0;
if (ipv6[39] != 0 || strlen(ipv6) != 39)
return;
memset(buf, 0, sizeof(buf));
// remove leading zeros from ipv6-input to buf, :0023: = :23:, :0000: = :0:
for (i = 0; i < 8; i++) {
ptr = ipv6 + i * 4 + i;
j = 0;
while (*ptr == '0' && j < 3) {
ptr++;
j++;
}
memcpy(&buf[k], ptr, 4 - j);
k += 4 - j;
buf[k++] = ':';
}
buf[k - 1] = 0;
// find the longest :0: chain
while ((ptr = strstr(buf, buf2)) != NULL) {
ptr2 = ptr;
strcat(buf2, "0:");
}
// if at least :0:0: is found, on the longest replace with ::, ptr2 shows where
if (ptr2 != NULL) {
buf2[strlen(buf2) - 2] = 0;
memset(ipv6, 0, 40);
// special case: 0000::....
if (buf + 1 == ptr2 && buf[0] == '0') {
ipv6[0] = ':';
l = -1;
} else
memcpy(ipv6, buf, ptr2 - buf + 1);
memcpy(ipv6 + (ptr2 - buf + 1 + l), ptr2 + strlen(buf2) - 1, strlen(buf) - (ptr2 - buf) - strlen(buf2) + 1);
// special case ....::0000
if (ipv6[strlen(ipv6) - 1] == '0' && ipv6[strlen(ipv6) - 2] == ':' && ptr2 - buf + 1 + strlen(buf2) == strlen(buf))
ipv6[strlen(ipv6) - 1] = 0;
} else
strcpy(ipv6, buf);
// if (strncmp(ipv6, "::ffff:", 7) == 0 && strlen(ipv6) <= 16) {
// printf("XXX beauty for ::ffff:123.123.132.123\n");
// }
}
unsigned char *thc_ipv62string(unsigned char *ipv6) {
char *string = malloc(33);
int a;
if (ipv6 != NULL && string != NULL) {
for (a = 0; a < 16; a++) {
if (ipv6[a] / 16 >= 10)
string[a * 2] = 'a' + ipv6[a] / 16 - 10;
else
string[a * 2] = '0' + ipv6[a] / 16;
if (ipv6[a] % 16 >= 10)
string[a * 2 + 1] = 'a' + ipv6[a] % 16 - 10;
else
string[a * 2 + 1] = '0' + ipv6[a] % 16;
}
string[32] = 0;
} else {
free(string);
return NULL;
}
return string;
}
unsigned char *thc_string2ipv6(unsigned char *string) {
unsigned char *ipv6 = malloc(16);
int a;
if (string != NULL && ipv6 != NULL) {
for (a = 0; a < 16; a++) {
ipv6[a] = (string[2 * a] >= 'a' ? 10 + string[2 * a] - 'a' : string[2 * a] - '0') * 16;
ipv6[a] += string[2 * a + 1] >= 'a' ? 10 + string[2 * a + 1] - 'a' : string[2 * a + 1] - '0';
}
} else {
free(ipv6);
return NULL;
}
return ipv6;
}
unsigned char *thc_string2notation(unsigned char *string) {
unsigned char *notation = malloc(40);
int a;
if (notation != NULL && string != NULL) {
for (a = 0; a < 8; a++) {
memcpy(notation + a * 5, string + a * 4, 4);
notation[4 + a * 5] = ':';
}
notation[39] = 0;
} else {
return NULL;
free(notation);
}
thc_notation2beauty(notation);
return notation;
}
unsigned char *thc_ipv62notation(unsigned char *ipv6) {
char *res, *ptr;
if (ipv6 == NULL)
return NULL;
if ((res = thc_ipv62string(ipv6)) == NULL)
return NULL;
ptr = thc_string2notation(res);
free(res);
return ptr;
}
int calculate_checksum(unsigned char *data, int data_len) {
int i = 0, checksum = 0;
if (debug)
thc_dump_data(data, data_len, "Checksum Packet Data");
while (i < data_len) {
if (i++ % 2 == 0)
checksum += *data++;
else
checksum += *data++ << 8;
}
checksum = (checksum & 0xffff) + (checksum >> 16);
checksum = htons(~checksum);
return checksum;
}
int checksum_pseudo_header(unsigned char *src, unsigned char *dst, unsigned char type, unsigned char *data, int length) {
unsigned char ptr[40 + length + 48];
int checksum;
if (((type != NXT_IP4 && type != NXT_ICMP4) && (src == NULL || dst == NULL)) || data == NULL || length < 0)
return -1;
if (length + 40 > 65535)
if (_thc_ipv6_showerrors)
fprintf(stderr, "Warning: checksums for packets > 65535 are unreliable due implementation differences on target platforms\n");
memset(&ptr, 0, 40 + length);
if (type == NXT_IP4 || type == NXT_IP4_RUDIMENTARY || type == NXT_ICMP4) {
memcpy(ptr, data, length);
checksum = calculate_checksum(ptr, length);
} else {
memcpy(&ptr[0], src, 16);
memcpy(&ptr[16], dst, 16);
ptr[34] = length / 256;
ptr[35] = length % 256;
ptr[39] = type;
if (data != NULL && length > 0)
memcpy(&ptr[40], data, length);
checksum = calculate_checksum(ptr, 40 + length);
}
/*if (length > 65495) {
printf("DEBUG length: %d, high: %d, low: %d, sum: %x\n", length, ptr[34], ptr[35], checksum);
printf("65535: %x\n", calculate_checksum(ptr, 65535));
printf("65536: %x\n", calculate_checksum(ptr, 65536));
printf("65535+40: %x\n", calculate_checksum(ptr, 65535 + 40));
printf("65535+40: %x\n", calculate_checksum(ptr, 65536 + 40));
}*/
if (type == NXT_UDP && checksum == 0)
checksum = 65535;
if (debug)
printf("Checksum: %d = %p, %p, %d, %p, %d\n", checksum, src, dst, type, data, length);
return checksum;
}
unsigned char *thc_resolve6(char *target) {
char *ret_addr, *ptr2, *ptr = target, tmp[264];
struct in6_addr glob_in6;
char *glob_addr = (char *) &glob_in6;
struct addrinfo glob_hints, *glob_result;
unsigned char out[64];
if (target == NULL)
return NULL;
if (index(target, '/') != NULL || *target == '[' || index(target, '%') != NULL) {
ptr = strncpy(tmp, target, sizeof(tmp) - 1);
tmp[sizeof(tmp) - 1] = 0;
if ((ptr2 = index(tmp, '/')) != NULL)
*ptr2 = 0;
if ((ptr2 = index(tmp, '%')) != NULL)
*ptr2 = 0;
if (*ptr == '[') {
ptr++;
if ((ptr2 = index(tmp, ']')) != NULL)
*ptr2 = 0;
}
}
memset(&glob_hints, 0, sizeof(glob_hints));
glob_hints.ai_family = AF_INET6;
if (getaddrinfo(ptr, NULL, &glob_hints, &glob_result) != 0)
return NULL;
if (getnameinfo(glob_result->ai_addr, glob_result->ai_addrlen, out, sizeof(out), NULL, 0, NI_NUMERICHOST) != 0)
return NULL;
if (inet_pton(AF_INET6, out, glob_addr) < 0)
return NULL;
if ((ret_addr = malloc(16)) == NULL)
return NULL;
memcpy(ret_addr, glob_in6.s6_addr, 16);
if (debug)
thc_dump_data(ret_addr, 16, "Target Resolve IPv6");
freeaddrinfo(glob_result);
return ret_addr;
}
int thc_get_mtu(char *interface) {
int s;
struct ifreq ifr;
static struct mtu_cache_entry {
char *intf;
int mtu;
} *mtu_cache = NULL;
static int mtu_cache_size = 0;
if (interface == NULL)
interface = default_interface;
/* lookup in the cache and save syscalls */
if (mtu_cache_size) {
int i;
for (i = 0; i < mtu_cache_size; i++) {
if (strcmp(interface, mtu_cache[i].intf) == 0)
return mtu_cache[i].mtu;
}
}
if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
return -1;
memset(&ifr, 0, sizeof(ifr));
snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", interface);
if (ioctl(s, SIOCGIFMTU, (int8_t *) & ifr) < 0) {
close(s);
return -1;
}
close(s);
if (debug)
printf("DEBUG: MTU %d\n", ifr.ifr_mtu);
/* Add MTU to the cache to avoid having to look it up again */
mtu_cache_size++;
mtu_cache = realloc(mtu_cache, mtu_cache_size * sizeof (*mtu_cache));
if (!mtu_cache)
exit(-1);
mtu_cache[mtu_cache_size-1].intf = strdup(interface);
mtu_cache[mtu_cache_size-1].mtu = ifr.ifr_mtu;
return ifr.ifr_mtu;
}
unsigned char *thc_get_own_mac(char *interface) {
int s;
struct ifreq ifr;
char *mac;
if (interface == NULL)
interface = default_interface;
if (_thc_ipv6_rawmode)
return thc_ipv6_dummymac();
#if !defined (SIOCGIFHWADDR)
struct ifaddrs *ifa, *ifx = NULL;
struct sockaddr_dl *dl;
getifaddrs(&ifa);
ifx = ifa;
if ((mac = malloc(6)) == NULL) {
perror("malloc");
return NULL;
}
while (ifa != NULL) {
dl = (struct sockaddr_dl *) ifa->ifa_addr;
if (debug)
thc_dump_data(dl->sdl_data, dl->sdl_nlen, "Interface loop");
if (dl->sdl_nlen > 0 && strncmp(interface, dl->sdl_data, dl->sdl_nlen) == 0) {
memcpy(mac, LLADDR(dl), 6);
break;
} else {
ifa = ifa->ifa_next;
}
}
if (ifa == NULL) {
freeifaddrs(ifx);
return NULL; // error: could not find requested interface.
} else {
freeifaddrs(ifx);
}
#else /* SIOCGIFHWADDR */
if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
return NULL;
memset(&ifr, 0, sizeof(ifr));
snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", interface);
if (ioctl(s, SIOCGIFHWADDR, (int8_t *) & ifr) < 0) {
close(s);
return NULL;
}
if ((mac = malloc(6)) == NULL) {
perror("malloc");
return NULL;
}
memcpy(mac, &ifr.ifr_hwaddr.sa_data, 6);
close(s);
#endif
if (debug)
thc_dump_data(mac, 6, "Own MAC address");
return mac;
}
unsigned char *thc_get_own_ipv6(char *interface, unsigned char *dst, int prefer) {
char *myipv6;
FILE *f;
unsigned char ipv6[36] = "", save[34] = "", tmpbuf[34], buf[1024], *tmpdst = NULL;
int a, b, c, done = 0, picky = 0, orig_prefer = prefer;
unsigned char tmpd, tmpb;
char bla[32];
if (interface == NULL)
interface = default_interface;
// -- we have a prefer setup, we should honor it
if (prefer != PREFER_GLOBAL && prefer != PREFER_LINK) {
if (dst != NULL) {
if (dst[0] == 0xff) {
if (dst[1] > 2)
prefer = PREFER_GLOBAL;
else
prefer = PREFER_LINK;
} else
if (dst[0] == 0xfe)
prefer = PREFER_LINK;
else
prefer = PREFER_GLOBAL;
} else
prefer = PREFER_GLOBAL; // this is the default
}
if (dst != NULL)
tmpdst = thc_ipv62string(dst);
memset(save, 0, sizeof(save));
while (done < 2 && picky < 3) {
if ((f = fopen("/proc/net/if_inet6", "r")) == NULL) {
fprintf(stderr, "Error: /proc/net/if_inet6 does not exist, no IPv6 support on your Linux box!\n");
if (tmpdst != NULL)
free(tmpdst);
return NULL;
}
if (picky == 1 && dst == NULL)
picky = 2;
if (picky == 1) {
dst = NULL;
tmpdst = NULL;
}
if (picky == 2) {
if (prefer == PREFER_GLOBAL)
prefer = PREFER_LINK;
else
prefer = PREFER_GLOBAL;
}
while (done < 2 && fgets(buf, sizeof(buf), f) != NULL) {
if (strncmp(interface, &buf[strlen(buf) - strlen(interface) - 1], strlen(interface)) == 0) {
sscanf(buf, "%s %x %x %x %s", tmpbuf, &a, &b, &c, bla);
if (c == prefer && done != 2) {
ipv6[0] = c; // scope type
ipv6[1] = b; // netmask
memcpy(&ipv6[2], tmpbuf, 32);
ipv6[34] = 0;
//printf("(c scope/prefer is %d) dst %p == NULL && ( prefer %d == %d PREFER_LINK || %c != f )\n", c, dst, prefer, PREFER_LINK, tmpbuf[0]);
if (dst == NULL && (prefer == PREFER_LINK || tmpbuf[0] != 'f'))
done = 2;
else
done = 1;
}
// if a destination was given, we always prefer the local ip which is in the same subnet of the target
if (dst != NULL) {
if (strncmp(tmpbuf, tmpdst, b / 4) == 0) {
if (b % 4 > 0) {
tmpb = tmpbuf[b / 4 + 1] >> (b % 4);
tmpd = tmpdst[b / 4 + 1] >> (b % 4);
if (tmpb == tmpd) {
done = 2;
}
} else
done = 2;
if (done == 2) {
if (debug)
printf("DEBUG: Found local IPv6 address to destination\n");
ipv6[0] = c; // scope type
ipv6[1] = b; // netmask
memcpy(&ipv6[2], tmpbuf, 32);
ipv6[34] = 0;
}
}
}
//printf("done is %d - %s - %s\n", done, tmpbuf, buf);
// ensure that 2000::/3 and fc00::/7 is selected correctly
if (done != 2 && dst != NULL) {
if (
((strncmp(tmpbuf, "fc", 2) == 0 || strncmp(tmpbuf, "fd", 2) == 0) && (strncmp(tmpdst, "fc", 2) == 0 || strncmp(tmpdst, "fd", 2) == 0))
||
((tmpdst[0] == '2' || tmpdst[0] == '3') && (tmpbuf[0] == '2' || tmpbuf[0] == '3')) ) {
/*
printf("SAVE! %s -> %s\n", tmpbuf, tmpdst);
memcpy(save + 2, tmpbuf, 32);
memset(ipv6, 0, sizeof(ipv6));
*/
done = 2;
}
//printf("here! %d => %c%c != %c%c \n", save[2], tmpbuf[0], tmpbuf[1], tmpdst[0], tmpdst[1]);
if ( save[2] == 0
&&
( ((strncmp(tmpbuf, "fc", 2) == 0 || strncmp(tmpbuf, "fd", 2) == 0) && (tmpdst[0] == '2' || tmpdst[0] == '3'))
||
((strncmp(tmpdst, "fc", 2) == 0 || strncmp(tmpdst, "fd", 2) == 0) && (tmpbuf[0] == '2' || tmpbuf[0] == '3')) ) ) {
//printf("RESORT! %c -> %c\n", tmpbuf[1], tmpdst[0]);
memcpy(save + 2, tmpbuf, 32);
memset(ipv6, 0, sizeof(ipv6));
done = 0;
}
}
//printf("final done is %d - %s - %s\n", done, tmpbuf, buf);
}
}
fclose(f);
picky++;
//printf("x %d, %s == 0, %s > 0\n", done, ipv6 + 2, save + 2 );
if (done < 2 && strlen(&ipv6[2]) == 0 && strlen(&save[2]) > 0) {
//printf("RESORT IS TAKEN => %s\n", save + 2);
memcpy(ipv6, save, sizeof(ipv6));
done = 2;
}
}
//printf("%s > 0, %s== fe80\n", save +2, ipv6 +2);
if (strlen(&save[2]) > 0 && prefer == PREFER_GLOBAL && strncmp(ipv6 + 2, "fe80", 2) == 0) {
//printf("z\n");
memcpy(ipv6, save, sizeof(ipv6));
done = 2;
}
if (strlen(&ipv6[2]) == 0) {
if (_thc_ipv6_showerrors)
fprintf(stderr, "Warning: no IPv6 address on interface defined\n");
if (tmpdst != NULL)
free(tmpdst);
return NULL;
}
if (picky == 2 && orig_prefer != ipv6[0])
if (_thc_ipv6_showerrors)
fprintf(stderr, "Warning: unprefered IPv6 address had to be selected\n");
if (tmpdst != NULL)
free(tmpdst);
tmpdst = thc_string2notation(&ipv6[2]);
myipv6 = thc_resolve6(tmpdst);
free(tmpdst);
if (debug)
thc_dump_data(myipv6, 16, "Own IPv6 address");
return myipv6;
}
unsigned char *thc_get_multicast_mac(unsigned char *dst) {
unsigned char *mac;
if (_thc_ipv6_rawmode)
return thc_ipv6_dummymac();
if (dst == NULL || (mac = malloc(6)) == NULL)
return NULL;
mac[0] = 0x33;
mac[1] = 0x33;
memcpy(&mac[2], dst + 12, 4);
return mac;
}
void thc_get_mac_from_sniff(u_char *foo, const struct pcap_pkthdr *header, const unsigned char *data) {
int off = 0, len = header->caplen - 14;
unsigned char *ptr = (unsigned char*)data + 14;
if (do_hdr_size) {
ptr += (do_hdr_size - 14);
len -= (do_hdr_size - 14);
if ((ptr[0] & 240) != 0x60)
return;
}
if (ptr[6] == NXT_FRAG) {
if (ptr[40] == NXT_ICMP6)
off = 8;
else
return;
} else
if (ptr[6] != NXT_ICMP6)
return;
if (ptr[40 + off] != ICMP6_NEIGHBORADV)
return;
if (len < 64 + off)
return;
if (memcmp(ptr + 48 + off, foo + 7, 16) != 0)
return;
foo[0] = 32;
if (len >= 72 && ptr[64 + off] == 2 && ptr[65 + off] == 1)
memcpy(foo + 1, ptr + 66 + off, 6);
else
memcpy(foo + 1, data + 6, 6);
}
unsigned char *thc_lookup_ipv6_mac(char *interface, unsigned char *dst) {
unsigned char *mac = NULL;
time_t curr;
int count = 0, found = 0;
char string[64] = "ip6 and dst ", resolved_mac[23] = "", *p1, *p2, *mysrc;
pcap_t *p;
if (thc_socket < 0)
thc_socket = thc_open_ipv6(interface);
if (_thc_ipv6_rawmode || do_pppoe || do_6in4 || do_hdr_vlan)
return thc_ipv6_dummymac();
if (dst == NULL)
return NULL;
if (interface == NULL)
interface = default_interface;
if ((p1 = thc_get_own_ipv6(interface, dst, PREFER_LINK)) == NULL)
return NULL;
mysrc = p1;
if ((p2 = thc_ipv62notation(p1)) == NULL) {
free(p1);
return NULL;
}
strcat(string, p2);
free(p2);
memcpy(resolved_mac + 7, dst, 16);
if ((p = thc_pcap_init(interface, string)) == NULL) {
free(mysrc);
return NULL;
}
while (found == 0 && count < 3) {
//printf("X %d %p %02x%02x %p %02x%02x\n", count, mysrc, mysrc[14], mysrc[15], dst, dst[14], dst[15]);
thc_neighborsol6(interface, mysrc, NULL, dst, NULL, NULL);
curr = time(NULL);
while (found == 0 && time(NULL) < curr + 2) {
thc_pcap_check(p, (char *) thc_get_mac_from_sniff, resolved_mac);
if (resolved_mac[0] != 0) {
found = 1;
if ((mac = malloc(6)) == NULL) {
free(mysrc);
return NULL;
}
memcpy(mac, resolved_mac + 1, 6);
}
}
count++;
}
thc_pcap_close(p);
free(mysrc);
if (debug)
thc_dump_data(mac, 6, "MAC address for packet target");
return mac;
}
/* If the following looks like shit to you:
This is code submitted by Dan Kaminksy with whom I bet that he is not
able to code a 1 page function which extracts the mac address from the
neighbor cache on linux - which is such a complex and horrible
implementation. Well you get what you ask for - a function which will
break once the interface even slightly changes ... but its 1 page.
*/
unsigned char *thc_look_neighborcache(unsigned char *dst) {
int fd, fromlen, gotsize, rcvbuf = 65535;
struct sockaddr_nl nladdr;
unsigned char buf[32768], *ptr, *found;
// char magic[] = { 0x80, 0x00, 0x00, 0x01, 0x14, 0x00, 0x01, 0x00 };
char blob[] = { 0x14, 0x00, 0x00, 0x00, 0x1e, 0x00, 0x01, 0x03, 0xda,
0x0f, 0xb8, 0x43, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
memset(&nladdr, 0, sizeof(struct sockaddr_nl));
nladdr.nl_family = AF_NETLINK;
setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &rcvbuf, sizeof(rcvbuf));
bind(fd, (struct sockaddr *) &nladdr, sizeof(nladdr));
sendto(fd, blob, sizeof(blob), 0, (struct sockaddr *) &nladdr, sizeof(nladdr));
fromlen = sizeof(nladdr);
gotsize = recvfrom(fd, buf, sizeof(buf), 0, (struct sockaddr *) &nladdr, &fromlen);
shutdown(fd, SHUT_RDWR);
close(fd);
if (debug)
thc_dump_data(buf, gotsize, "Neighbor cache lookup result");
// if ((ptr = thc_memstr(buf, magic, gotsize, sizeof(magic))) == NULL)
// return NULL;
if ((ptr = thc_memstr(buf, dst, gotsize /* - (ptr - buf) */ , 16)) == NULL)
return NULL;
if ((found = malloc(7)) == NULL)
return NULL;
memcpy(found, ptr + 16 + 4, 6);
found[6] = 0;
return found;
}
int thc_is_dst_local(char *interface, unsigned char *dst) {
int local = 0;
FILE *f;
unsigned char tmpbuf[34], buf[1024], *tmpdst = NULL;
int a, b, c /*, found = 0, fd = -1 */ ;
unsigned char tmpd, tmpb;
char bla[32];
if (thc_socket < 0)
thc_socket = thc_open_ipv6(interface);
if (_thc_ipv6_rawmode || dst == NULL || do_pppoe || do_6in4 || do_hdr_vlan)
return 0;
if (interface == NULL)
interface = default_interface;
if (dst[0] == 0xff) // multicast address ?
return 1;
if (dst[0] == 0xfe && dst[1] == 0x80) // link local
return 1;
tmpdst = thc_ipv62string(dst);
if ((f = fopen("/proc/net/if_inet6", "r")) == NULL) {
fprintf(stderr, "Error: /proc/net/if_inet6 does not exist, no IPv6 support on your Linux box!\n");
exit(-1);
}
while (local == 0 && fgets(buf, sizeof(buf), f) != NULL) {
if (strncmp(interface, &buf[strlen(buf) - strlen(interface) - 1], strlen(interface)) == 0) {
sscanf(buf, "%s %x %x %x %s", tmpbuf, &a, &b, &c, bla);
if (strncmp(tmpbuf, tmpdst, b / 4) == 0) {
if (b % 4 > 0) {
tmpb = tmpbuf[b / 4 + 1] >> (b % 4);
tmpd = tmpdst[b / 4 + 1] >> (b % 4);
if (tmpb == tmpd) {
local = 1;
}
} else
local = 1;
}
}
}
fclose(f);
if (debug)
printf("DEBUG: is dst local: %d\n", local);
free(tmpdst);
return local;
}
unsigned char *thc_get_mac(char *interface, unsigned char *src, unsigned char *dst) {
int local = 0;
FILE *f;
unsigned char tmpbuf[34], router1[34], router2[34], defaultgw[34] = "", buf[1024], *tmpdst = NULL;
int a, b, c /*, found = 0, fd = -1 */ ;
unsigned char tmpd, tmpb;
char bla[32], *ret, *p1;
if (thc_socket < 0)
thc_socket = thc_open_ipv6(interface);
if (_thc_ipv6_rawmode || do_pppoe || do_6in4 || do_hdr_vlan)
return thc_ipv6_dummymac();
if (dst == NULL)
return NULL;
if (interface == NULL)
interface = default_interface;
if (dst[0] == 0xff) // then its a multicast target
return thc_get_multicast_mac(dst);
tmpdst = thc_ipv62string(dst);
if ((f = fopen("/proc/net/if_inet6", "r")) == NULL) {
fprintf(stderr, "Error: /proc/net/if_inet6 does not exist, no IPv6 support on your Linux box!\n");
exit(-1);
}
while (local == 0 && fgets(buf, sizeof(buf), f) != NULL) {
if (strncmp(interface, &buf[strlen(buf) - strlen(interface) - 1], strlen(interface)) == 0) {
sscanf(buf, "%s %x %x %x %s", tmpbuf, &a, &b, &c, bla);
if (strncmp(tmpbuf, tmpdst, b / 4) == 0) {
if (b % 4 > 0) {
tmpb = tmpbuf[b / 4 + 1] >> (b % 4);
tmpd = tmpdst[b / 4 + 1] >> (b % 4);
if (tmpb == tmpd) {
local = 1;
}
} else
local = 1;
}
}
}
fclose(f);
if (debug)
printf("DEBUG: is mac local: %d\n", local);
if (!local) {
if ((f = fopen("/proc/net/ipv6_route", "r")) == NULL) {
fprintf(stderr, "Error: /proc/net/ipv6_route does not exist, no IPv6 support on your Linux box!\n");
exit(-1);
}
while (local == 0 && fgets(buf, sizeof(buf), f) != NULL) {
if (strncmp(interface, &buf[strlen(buf) - strlen(interface) - 1], strlen(interface)) == 0) {
sscanf(buf, "%s %x %s %x %s %s", tmpbuf, &b, router1, &a, router2, bla);
if (b > 0) {
if (strncmp(tmpbuf, tmpdst, b / 4) == 0) {
if (b % 4 > 0) {
tmpb = tmpbuf[b / 4 + 1] >> (b % 4);
tmpd = tmpdst[b / 4 + 1] >> (b % 4);
if (tmpb == tmpd)
local = 1;
} else
local = 1;
}
} else
strcpy(defaultgw, router2);
if (local == 1) {
if (debug)
printf("DEBUG: router found for %s: %s\n", tmpdst, router2);
strcpy(tmpdst, router2);
}
}
}
if (local == 0 && strlen(defaultgw) > 0) {
if (debug)
printf("DEBUG: using default router for %s: %s\n", tmpdst, defaultgw);
strcpy(tmpdst, defaultgw);
local = 1;
}
if (local == 0) {
if (_thc_ipv6_showerrors)
fprintf(stderr, "Error: No idea where to route the packet to %s!\n", tmpdst);
fclose(f);
free(tmpdst);
return NULL;
}
fclose(f);
}
p1 = thc_string2ipv6(tmpdst);
if ((ret = thc_look_neighborcache(p1)) != NULL) {
free(p1);
free(tmpdst);
return ret;
}
ret = thc_lookup_ipv6_mac(interface, p1);
free(tmpdst);
free(p1);
return ret;
}
unsigned char *thc_inverse_packet(unsigned char *pkt, int pkt_len) {
unsigned char tmp[16];
int type = -1, iptr = 0, checksum;
char *src = &pkt[8], *dst = &pkt[24];
if (pkt == NULL)
return NULL;
pkt[7] = 255; // ttl
memcpy(tmp, pkt + 8, 16); // reverse IP6 src and dst
memcpy(pkt + 8, pkt + 24, 16);