Gerard Wagener
parent
2152465c2b
commit
48696b8668
|
|
@ -0,0 +1,8 @@
|
|||
pibs: pibs.o
|
||||
gcc -Wall -o pibs pibs.o -lwiretap `pkg-config --libs glib-2.0` -lpcap -lhiredis -ggdb
|
||||
pibs.o: pibs.c
|
||||
gcc -D HASHDEBUG=0 -Wall -c pibs.c `pkg-config --cflags glib-2.0` -I /usr/include/wireshark/wiretap -I /usr/include/wireshark/wsutil -I /usr/include/wireshark `pkg-config --libs glib-2.0` -I /usr/local/include/hiredis -ggdb
|
||||
|
||||
clean:
|
||||
-rm pibs
|
||||
-rm *.o
|
||||
|
|
@ -0,0 +1,468 @@
|
|||
/*
|
||||
* pibs - Passive Identification of BackScatter
|
||||
*
|
||||
* Copyright (C) 2019 Gerard Wagener
|
||||
* Copyright (C) 2019 CIRCL Computer Incident Response Center Luxembourg
|
||||
* (SMILE gie).
|
||||
*
|
||||
* This program is free software: you can redistribute it and/or modify
|
||||
* it under the terms of the GNU Affero General Public License as published by
|
||||
* the Free Software Foundation, either version 3 of the License, or
|
||||
* (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU Affero General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU Affero General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*/
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <getopt.h>
|
||||
#include <assert.h>
|
||||
#include <string.h>
|
||||
#include <pcap/pcap.h>
|
||||
#include <wtap.h>
|
||||
#include <wtap-int.h>
|
||||
#include <unistd.h>
|
||||
#include <signal.h>
|
||||
#include <netinet/ip.h>
|
||||
#include <netinet/in.h>
|
||||
#include <netinet/tcp.h>
|
||||
#include <arpa/inet.h>
|
||||
#include <sys/socket.h>
|
||||
#include <sys/ipc.h>
|
||||
#include <sys/shm.h>
|
||||
#include <errno.h>
|
||||
|
||||
#include <hiredis/hiredis.h>
|
||||
|
||||
//TODO test other values
|
||||
#define NBINS 1024 //Number of bins
|
||||
#define NBINITEMS 255 //Number of items per bin
|
||||
#define SZBIN 4
|
||||
#define NBINSCALE 2 // Scaling factor of the entire datastructure
|
||||
|
||||
#define HDBG(...) if (HASHDEBUG) fprintf(stderr, __VA_ARGS__)
|
||||
|
||||
#define ERR_ATTACH_NOT_EMPTY 11
|
||||
#define ERR_NO_SHMID_FILE 12
|
||||
|
||||
typedef struct pibs_header_s {
|
||||
uint8_t magic [4];
|
||||
uint8_t version;
|
||||
//Put some useful stuff here
|
||||
uint32_t next_item;
|
||||
uint32_t bin_offset;
|
||||
uint64_t data_size;
|
||||
uint32_t max_item;
|
||||
uint8_t padding [3];
|
||||
} pibs_header_t;
|
||||
|
||||
|
||||
/* TODO This can squezed. Timestamp can be expressed on 8 bits i.e. relative
|
||||
* minutes
|
||||
* IP can be represented with 16 bits ipaddr = ip / bin_size
|
||||
* Not sure if space can be saved in usual cases
|
||||
*/
|
||||
typedef struct item_s {
|
||||
uint32_t timestamp;
|
||||
uint32_t next_item;
|
||||
uint32_t ipaddr;
|
||||
} item_t;
|
||||
|
||||
/* Need to hash source IP addresses and record first seen and flags */
|
||||
typedef struct pibs_s {
|
||||
int errno_copy;
|
||||
int errno_pibs;
|
||||
char *filename;
|
||||
int should_dump_table;
|
||||
int show_backscatter;
|
||||
int show_stats;
|
||||
int should_create_shm;
|
||||
int should_attach;
|
||||
//TODO use self contained data structure that can be easily serialized
|
||||
//Put data structure in an entire block to easier serialize
|
||||
uint8_t *data;
|
||||
uint32_t next_block;
|
||||
uint32_t next_item;
|
||||
uint32_t bin_offset;
|
||||
uint64_t data_size;
|
||||
uint32_t* bin_table;
|
||||
uint32_t max_item;
|
||||
item_t* items;
|
||||
int shmid;
|
||||
char shmid_file [FILENAME_MAX];
|
||||
} pibs_t;
|
||||
|
||||
int load_shmid_file(pibs_t* pibs)
|
||||
{
|
||||
FILE* fp;
|
||||
if (pibs->shmid_file[0]) {
|
||||
fp = fopen(pibs->shmid_file,"r");
|
||||
if (fp) {
|
||||
//FIXME check file
|
||||
fscanf(fp, "%d", &pibs->shmid);
|
||||
return pibs->shmid;
|
||||
}
|
||||
} else {
|
||||
pibs->errno_pibs = ERR_NO_SHMID_FILE;
|
||||
}
|
||||
return -1;
|
||||
}
|
||||
|
||||
//TODO when attaching the next_item must be recovered if results
|
||||
//of previous runs need to be increased
|
||||
int pibs_shmat(pibs_t* pibs)
|
||||
{
|
||||
/* FIXME init function needs to break up in two functions. One that
|
||||
* initializes internal pibs structures as cli options etc
|
||||
* a second one for describing the data itself, size of bin_table
|
||||
* number of items etc.
|
||||
*/
|
||||
if (pibs->data) {
|
||||
free(pibs->data);
|
||||
pibs->data = NULL;
|
||||
}
|
||||
if (pibs->data) {
|
||||
pibs->errno_pibs = ERR_ATTACH_NOT_EMPTY;
|
||||
printf("TEST Data is not null\n");
|
||||
return -1;
|
||||
}
|
||||
if (!pibs->shmid_file[0]) {
|
||||
pibs->errno_pibs = ERR_NO_SHMID_FILE;
|
||||
return -1;
|
||||
}
|
||||
if (load_shmid_file(pibs) > 0) {
|
||||
pibs->data = shmat(pibs->shmid, NULL, SHM_RND);
|
||||
if ( (int) pibs->data == -1) {
|
||||
pibs->errno_copy = errno;
|
||||
} else {
|
||||
return 1;
|
||||
}
|
||||
}
|
||||
// Something did not work
|
||||
return -1;
|
||||
}
|
||||
|
||||
int pibs_shmget(pibs_t* pibs)
|
||||
{
|
||||
FILE* fp;
|
||||
pibs->shmid = shmget(IPC_PRIVATE, pibs->data_size, IPC_CREAT | 0600);
|
||||
if (pibs->shmid < 0) {
|
||||
pibs->errno_copy = errno;
|
||||
}
|
||||
|
||||
if (pibs->shmid_file[0]){
|
||||
fp = fopen(pibs->shmid_file, "w");
|
||||
if (fp) {
|
||||
fprintf(fp,"%d",pibs->shmid);
|
||||
fclose(fp);
|
||||
}
|
||||
//TODO error handling
|
||||
}
|
||||
//TODO attach to it and bzero it
|
||||
//setup the tables
|
||||
return pibs->shmid;
|
||||
}
|
||||
|
||||
/*
|
||||
* Returns -1 if not found
|
||||
* returns last timestamp if found
|
||||
*/
|
||||
int_fast64_t get_last_timestamp(pibs_t* pibs, uint32_t ip)
|
||||
{
|
||||
uint32_t idx;
|
||||
uint32_t i;
|
||||
//TODO explore alternative hashing functions
|
||||
//https://stackoverflow.com/questions/664014/what-integer-hash-function-are-good-that-accepts-an-integer-hash-key/12996028#12996028
|
||||
idx = ip % NBINS;
|
||||
HDBG("[TS] Checking for IP %x at index = %d\n", ip, idx);
|
||||
i = pibs->bin_table[idx];
|
||||
while (i){
|
||||
if (pibs->items[i].ipaddr == ip) {
|
||||
HDBG("[TS] Found item %x at position %d\n", ip , i);
|
||||
return pibs->items[i].timestamp;
|
||||
}
|
||||
i = pibs->items[i].next_item;
|
||||
}
|
||||
HDBG("[TS] IP: %x was not found return -1\n",ip);
|
||||
return -1;
|
||||
}
|
||||
|
||||
void insert_ip(pibs_t* pibs, uint32_t ip, uint32_t ts)
|
||||
{
|
||||
uint32_t idx;
|
||||
uint32_t i;
|
||||
uint32_t parent;
|
||||
|
||||
idx = ip % NBINS;
|
||||
HDBG("[INS] Lookup IP address %x. Hashed value: %d\n", ip, idx);
|
||||
parent = 0;
|
||||
if (pibs->bin_table[idx]){
|
||||
// There is already someone in the bin
|
||||
i = pibs->bin_table[idx];
|
||||
HDBG("[INS] Starting searching at position %d\n", i);
|
||||
do {
|
||||
HDBG("[INS] Iterating items at index %d. Current position: %d.\
|
||||
Next position = %d\n",
|
||||
idx,i,pibs->items[i].next_item);
|
||||
HDBG("[INS] Checking IP at address %p\n",&pibs->items[i]);
|
||||
if (pibs->items[i].ipaddr == ip) {
|
||||
HDBG("[INS] Found item %x at position %d\n", ip , i);
|
||||
HDBG("[INS] New timestamp for ip %x is %d\n",ip,ts);
|
||||
pibs->items[i].timestamp = ts;
|
||||
return;
|
||||
}
|
||||
parent = i;
|
||||
i = pibs->items[i].next_item;
|
||||
} while (i != 0 );
|
||||
HDBG("[INS] The IP %x was not found in the item list, last parent %d\n",
|
||||
ip, parent);
|
||||
}
|
||||
// The IP was not found in an item list or the hashed value wsa not present
|
||||
// in the bin table, so create a new item
|
||||
pibs->next_item++;
|
||||
if (pibs->next_item > pibs->max_item) {
|
||||
printf("FIXME run out of memory. Do something better than abort\n");
|
||||
//Go through old timestamps and keep linked list of stuff that can be
|
||||
//reused or do kind of defragmentation
|
||||
abort();
|
||||
}
|
||||
if (pibs->bin_table[idx] == 0) {
|
||||
pibs->bin_table[idx] = pibs->next_item;
|
||||
}
|
||||
HDBG("[INS] Insert ip %x at position %d, parent = %d\n", ip,
|
||||
pibs->next_item,parent);
|
||||
pibs->items[pibs->next_item].ipaddr = ip;
|
||||
pibs->items[pibs->next_item].timestamp = ts;
|
||||
if (parent) {
|
||||
pibs->items[parent].next_item = pibs->next_item;
|
||||
}
|
||||
}
|
||||
|
||||
void process_frame(pibs_t* pibs, wtap *wth,
|
||||
uint8_t *buf, size_t length)
|
||||
{
|
||||
struct ip* ipv4;
|
||||
uint32_t ip;
|
||||
struct tcphdr* tcp;
|
||||
int_fast64_t lastseen;
|
||||
|
||||
if (length < sizeof(struct ip)) {
|
||||
return;
|
||||
}
|
||||
|
||||
|
||||
ipv4 = (struct ip*)buf;
|
||||
// Focus only on TCP packets
|
||||
if (ipv4->ip_p != 6)
|
||||
return;
|
||||
|
||||
tcp = (struct tcphdr*)(buf+sizeof(struct ip));
|
||||
|
||||
memcpy(&ip, &ipv4->ip_src, 4);
|
||||
// Record only source ips where syn flag is set
|
||||
// TODO check other connection establishment alternatives
|
||||
if (tcp->th_flags == 2 ){
|
||||
insert_ip(pibs, ip, wth->rec.ts.secs);
|
||||
return;
|
||||
}
|
||||
|
||||
lastseen = get_last_timestamp(pibs, ip);
|
||||
|
||||
if (lastseen > 0){
|
||||
HDBG("IP %x %s was already seen before at %ld. Time difference %ld.\n"
|
||||
, ip, inet_ntoa(ipv4->ip_src), lastseen, wth->rec.ts.secs-lastseen);
|
||||
return;
|
||||
}
|
||||
// TODO keep these IPs in a hashtable and rank them
|
||||
if (pibs->show_backscatter) {
|
||||
printf("Potential backscatter. IP. %s. TCP flags: %d. Source port:%d \n",
|
||||
inet_ntoa(ipv4->ip_src), tcp->th_flags, ntohs(tcp->th_sport));
|
||||
}
|
||||
//TODO relative time
|
||||
//Purge old ips?
|
||||
}
|
||||
|
||||
void process_file(pibs_t* pibs)
|
||||
{
|
||||
wtap *wth;
|
||||
int err;
|
||||
char *errinfo;
|
||||
gint64 data_offset;
|
||||
int ethertype;
|
||||
guint8 *buf;
|
||||
|
||||
fprintf(stderr,"Processing %s\n",pibs->filename);
|
||||
wth = wtap_open_offline ( pibs->filename, WTAP_TYPE_AUTO, (int*)&err,
|
||||
(char**)&errinfo, FALSE);
|
||||
if (wth) {
|
||||
/* Loop over the packets and adjust the headers */
|
||||
while (wtap_read(wth, &err, &errinfo, &data_offset)) {
|
||||
if (wth->rec.rec_type == REC_TYPE_PACKET) {
|
||||
if (wth->rec.tsprec == WTAP_TSPREC_USEC){
|
||||
if (wth->rec.rec_header.packet_header.caplen < 14) {
|
||||
fprintf(stderr,"Packet too small, skip\n");
|
||||
continue;
|
||||
}
|
||||
}
|
||||
buf = wth->rec_data->data;
|
||||
ethertype = buf[12] << 8 | buf[13];
|
||||
// TODO Focus on IPv4 only
|
||||
if (ethertype == 0x0800) {
|
||||
process_frame(pibs, wth, buf+14, wth->rec.rec_header.packet_header.caplen -14);
|
||||
}
|
||||
}
|
||||
}
|
||||
wtap_close(wth);
|
||||
fprintf(stderr,"[INFO] Processing of filename %s done\n",pibs->filename);
|
||||
}else{
|
||||
fprintf(stderr, "[ERROR] Could not open filename %s,cause=%s\n",pibs->filename,
|
||||
wtap_strerror(err));
|
||||
}
|
||||
}
|
||||
|
||||
pibs_t* init(void)
|
||||
{
|
||||
pibs_t *pibs;
|
||||
|
||||
wtap_init(FALSE);
|
||||
pibs=calloc(sizeof(pibs_t),1);
|
||||
//TODO check if size is correct
|
||||
pibs->data_size = sizeof(pibs_header_t) + NBINSCALE * NBINS * SZBIN * NBINITEMS * sizeof(item_t);
|
||||
pibs->data = calloc(pibs->data_size,1);
|
||||
pibs->filename = calloc(FILENAME_MAX,1);
|
||||
printf("#Internal look up structure size in bytes: %ld\n", pibs->data_size);
|
||||
// Build header
|
||||
pibs->data[0]='P';
|
||||
pibs->data[1] = 'I';
|
||||
pibs->data[2] = 'B';
|
||||
pibs->data[3] = 'S';
|
||||
pibs->data[4] = 1; //version 1
|
||||
pibs->next_block = sizeof(pibs_header_t);
|
||||
pibs->bin_offset = pibs->next_block;
|
||||
printf("#data address is %p\n",pibs->data);
|
||||
pibs->bin_table = (uint32_t*)(pibs->data+pibs->bin_offset);
|
||||
printf("#bin_table address is %p\n", pibs->bin_table);
|
||||
// Create bins
|
||||
pibs->next_block+=SZBIN * NBINS;
|
||||
printf("#next block %d\n", pibs->next_block);
|
||||
pibs->items = (item_t*)(pibs->data+pibs->next_block);
|
||||
pibs->next_item = 0;
|
||||
printf("#items are address %p\n", pibs->items);
|
||||
pibs->max_item = NBINS * NBINITEMS;
|
||||
printf("#max_item: %d\n", pibs->max_item);
|
||||
return pibs;
|
||||
}
|
||||
|
||||
void pibs_dump_raw(pibs_t* pibs)
|
||||
{
|
||||
int i;
|
||||
printf("#RAW table dump\n");
|
||||
printf("#Index next_item\n");
|
||||
printf("#BINs\n");
|
||||
for (i=0; i< NBINS; i++) {
|
||||
printf("%d %d\n", i, pibs->bin_table[i]);
|
||||
}
|
||||
printf("#ITEMS\n");
|
||||
printf("#Index next_item, timestamp, ipaddr\n");
|
||||
for (i=0; i < NBINITEMS * NBINS; i++) {
|
||||
printf("%d %d %d %x\n", i, pibs->items[i].next_item,
|
||||
pibs->items[i].timestamp,
|
||||
pibs->items[i].ipaddr);
|
||||
}
|
||||
}
|
||||
|
||||
void pibs_dump_stats(pibs_t* pibs)
|
||||
{
|
||||
int i;
|
||||
int j;
|
||||
int cnt;
|
||||
uint64_t sum;
|
||||
sum = 0;
|
||||
printf("#Bin table\n");
|
||||
printf("#Bin number, Item offset, number of items\n");
|
||||
for (i=0; i < NBINS; i++) {
|
||||
j= pibs->bin_table[i];
|
||||
cnt = 0;
|
||||
while (j) {
|
||||
cnt++;
|
||||
j=pibs->items[j].next_item;
|
||||
}
|
||||
sum+=cnt;
|
||||
printf("%d %d %d\n", i, pibs->bin_table[i], cnt);
|
||||
}
|
||||
printf("#Number of unique IP addresses: %ld\n", sum);
|
||||
}
|
||||
|
||||
int main(int argc, char* argv[])
|
||||
{
|
||||
|
||||
int opt;
|
||||
pibs_t* pibs;
|
||||
|
||||
pibs = init();
|
||||
|
||||
fprintf(stderr, "[INFO] pid = %d\n",(int)getpid());
|
||||
|
||||
while ((opt = getopt(argc, argv, "r:dbsni:a")) != -1) {
|
||||
switch (opt) {
|
||||
case 'r':
|
||||
strncpy(pibs->filename, optarg, FILENAME_MAX);
|
||||
break;
|
||||
case 'd':
|
||||
pibs->should_dump_table = 1;
|
||||
break;
|
||||
case 'b':
|
||||
pibs->show_backscatter = 1;
|
||||
break;
|
||||
case 's':
|
||||
pibs->show_stats = 1;
|
||||
break;
|
||||
case 'n':
|
||||
pibs->should_create_shm = 1;
|
||||
break;
|
||||
case 'i':
|
||||
strncpy(pibs->shmid_file, optarg, FILENAME_MAX);
|
||||
break;
|
||||
case 'a':
|
||||
pibs->should_attach = 1;
|
||||
break;
|
||||
|
||||
default: /* '?' */
|
||||
|
||||
fprintf(stderr, "[ERROR] Invalid command line was specified\n");
|
||||
}
|
||||
}
|
||||
if (pibs->should_create_shm) {
|
||||
pibs_shmget(pibs);
|
||||
if (pibs->shmid >0){
|
||||
printf("Create a new shared memory segment %d\n", pibs->shmid);
|
||||
} else {
|
||||
printf("Failed to get shared memory segment. Cause = %s\n",
|
||||
strerror(pibs->errno_copy));
|
||||
}
|
||||
}
|
||||
if (pibs->should_attach) {
|
||||
if (pibs_shmat(pibs) > 0 ) {
|
||||
printf("Attached to shared memory segment %d\n", pibs->shmid);
|
||||
} else {
|
||||
printf("Failed to attach to shared memory segment. System error:%s\n",
|
||||
strerror(pibs->errno_copy));
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
}
|
||||
if (pibs->filename[0]) {
|
||||
process_file(pibs);
|
||||
}
|
||||
if (pibs->should_dump_table){
|
||||
pibs_dump_raw(pibs);
|
||||
}
|
||||
if (pibs->show_stats){
|
||||
pibs_dump_stats(pibs);
|
||||
}
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
Loading…
Reference in New Issue