+++ /dev/null
-/*
- socketkiller a tool to kill off established tcp connections
-
- Copyright (C) Ronnie Sahlberg 2007
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 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 General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
-
-#include "includes.h"
-#include "lib/events/events.h"
-#include "system/filesys.h"
-#include "system/network.h"
-#include "popt.h"
-#include "cmdline.h"
-#include "../include/ctdb.h"
-#include "../include/ctdb_private.h"
-#include <netinet/if_ether.h>
-
-/*
- uint16 checksum for n bytes
- */
-static uint32_t uint16_checksum(uint16_t *data, size_t n)
-{
- uint32_t sum=0;
- while (n>=2) {
- sum += (uint32_t)ntohs(*data);
- data++;
- n -= 2;
- }
- if (n == 1) {
- sum += (uint32_t)ntohs(*(uint8_t *)data);
- }
- return sum;
-}
-
-/*
- simple TCP checksum - assumes data is multiple of 2 bytes long
- */
-static uint16_t tcp_checksum(uint16_t *data, size_t n, struct iphdr *ip)
-{
- uint32_t sum = uint16_checksum(data, n);
- uint16_t sum2;
- sum += uint16_checksum((uint16_t *)&ip->saddr, sizeof(ip->saddr));
- sum += uint16_checksum((uint16_t *)&ip->daddr, sizeof(ip->daddr));
- sum += ip->protocol + n;
- sum = (sum & 0xFFFF) + (sum >> 16);
- sum = (sum & 0xFFFF) + (sum >> 16);
- sum2 = htons(sum);
- sum2 = ~sum2;
- if (sum2 == 0) {
- return 0xFFFF;
- }
- return sum2;
-}
-
-static int send_tcp(const struct sockaddr_in *dest, const struct sockaddr_in *src, uint32_t seq, uint32_t ack, int rst)
-{
- int s, ret;
- uint32_t one = 1;
- struct {
- struct iphdr ip;
- struct tcphdr tcp;
- } pkt;
-
-
- /* for now, we only handle AF_INET addresses */
- if (src->sin_family != AF_INET || dest->sin_family != AF_INET) {
- DEBUG(0,(__location__ " not an ipv4 address\n"));
- return -1;
- }
-
- s = socket(AF_INET, SOCK_RAW, htons(IPPROTO_RAW));
- if (s == -1) {
- DEBUG(0,(__location__ " failed to open raw socket (%s)\n",
- strerror(errno)));
- return -1;
- }
-
- ret = setsockopt(s, SOL_IP, IP_HDRINCL, &one, sizeof(one));
- if (ret != 0) {
- DEBUG(0,(__location__ " failed to setup IP headers (%s)\n",
- strerror(errno)));
- close(s);
- return -1;
- }
-
- ZERO_STRUCT(pkt);
- pkt.ip.version = 4;
- pkt.ip.ihl = sizeof(pkt.ip)/4;
- pkt.ip.tot_len = htons(sizeof(pkt));
- pkt.ip.ttl = 255;
- pkt.ip.protocol = IPPROTO_TCP;
- pkt.ip.saddr = src->sin_addr.s_addr;
- pkt.ip.daddr = dest->sin_addr.s_addr;
- pkt.ip.check = 0;
-
- pkt.tcp.source = src->sin_port;
- pkt.tcp.dest = dest->sin_port;
- pkt.tcp.seq = seq;
- pkt.tcp.ack_seq = ack;
- pkt.tcp.ack = 1;
- if (rst) {
- pkt.tcp.rst = 1;
- }
- pkt.tcp.doff = sizeof(pkt.tcp)/4;
- pkt.tcp.window = htons(1234);
- pkt.tcp.check = tcp_checksum((uint16_t *)&pkt.tcp, sizeof(pkt.tcp), &pkt.ip);
-
- ret = sendto(s, &pkt, sizeof(pkt), 0, dest, sizeof(*dest));
- if (ret != sizeof(pkt)) {
- DEBUG(0,(__location__ " failed sendto (%s)\n", strerror(errno)));
- close(s);
- return -1;
- }
-
- close(s);
- return 0;
-}
-
-
-static void usage(void)
-{
- printf("Usage: socketkiller <SRCIP> <SRCPORT> <DSTIP> <DSTPORT>\n");
-}
-
-int main(int argc, char *argv[])
-{
- struct sockaddr_in src,dst;
-
- if(argc!=5){
- usage();
- _exit(10);
- }
- int s, ret;
-#define RCVPKTSIZE 100
- char pkt[RCVPKTSIZE];
- struct ether_header *eth;
- struct iphdr *ip;
- struct tcphdr *tcp;
-
- src.sin_family=AF_INET;
- src.sin_port=htons(atoi(argv[2]));
- inet_aton(argv[1], &src.sin_addr);
-
- dst.sin_family=AF_INET;
- dst.sin_port=htons(atoi(argv[4]));
- inet_aton(argv[3], &dst.sin_addr);
-
-
- /* wait for up to 5 seconds before giving up */
- alarm(5);
-
- s=socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
-
- send_tcp(&dst, &src, 0, 0, 0);
-
- while (1) {
- ret = recv(s, pkt, RCVPKTSIZE, MSG_TRUNC);
- if (ret<40) {
- continue;
- }
-
- /* Ethernet */
- eth = (struct ether_header *)pkt;
- /* We only want IP packets */
- if (ntohs(eth->ether_type) != ETHERTYPE_IP) {
- continue;
- }
-
- /* IP */
- ip = (struct iphdr *)&pkt[14];
- /* We only want IPv4 packets */
- if (ip->version != 4) {
- continue;
- }
- /* Dont look at fragments */
- if ((ntohs(ip->frag_off)&0x1fff) != 0) {
- continue;
- }
- /* we only want TCP */
- if (ip->protocol != IPPROTO_TCP) {
- continue;
- }
-
- /* We only want packets sent from the guy we tickled */
- if (ip->saddr != dst.sin_addr.s_addr) {
- continue;
- }
- /* We only want packets sent to us */
- if (ip->daddr != src.sin_addr.s_addr) {
- continue;
- }
-
- /* TCP */
- tcp = (struct tcphdr *)&pkt[14+ip->ihl*4];
- /* We only want replies from the port we tickled */
- if (tcp->source != dst.sin_port) {
- continue;
- }
- if (tcp->dest != src.sin_port) {
- continue;
- }
-
- printf("sending a RESET to tear down the connection\n");
- send_tcp(&dst, &src, tcp->ack_seq, tcp->seq, 1);
- close(s);
- _exit(0);
- }
-
- close(s);
- return 1;
-}
projects / thirdparty / samba.git / commitdiff
