+++ /dev/null
-/*
- * idnlookup - ICMP Domain Name lookup utility for Linux
- * Should be installed SUID root, even though I don't know if it's secure yet. :-)
- * Copyright (C) 2005 Fredrik Tolf <fredrik@dolda2000.com>
- *
- * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-*/
-#include <stdlib.h>
-#include <unistd.h>
-#include <stdio.h>
-#include <string.h>
-#include <errno.h>
-#include <netdb.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <netinet/ip.h>
-#include <netinet/ip6.h>
-#include <arpa/inet.h>
-#include <sys/types.h>
-#include <sys/poll.h>
-#include <sys/time.h>
-
-struct icmphdr {
- u_int8_t type;
- u_int8_t code;
- u_int16_t checksum;
-};
-
-struct reqhdr {
- u_int8_t type;
- u_int8_t code;
- u_int16_t checksum;
- u_int16_t id;
- u_int16_t seq;
-};
-
-struct rephdr {
- u_int8_t type;
- u_int8_t code;
- u_int16_t checksum;
- u_int16_t id;
- u_int16_t seq;
- int32_t ttl;
-
-};
-
-#define ICMP_NAMEREQ 37
-#define ICMP_NAMEREP 38
-
-unsigned char buf[65536];
-
-/* DN decompression not yet implemented, since I don't know where to
- * begin counting the offset from -- the beginning of the ICMP
- * payload, or from the beginning of the DN data buffer? */
-void printdn(FILE *f, unsigned char *dnbuf, size_t size, int onlyfirst)
-{
- unsigned char *p;
-
- p = dnbuf;
- while(p - dnbuf < size) {
- while(*p != 0) {
- if(*p & 0xc0) {
- fprintf(stderr, "domain name decompression not implemented, aborting\n");
- exit(1);
- }
- fprintf(f, "%.*s", (int)*p, p + 1);
- p += 1 + (int)*p;
- if(*p != 0)
- fprintf(f, ".");
- }
- p++;
- fprintf(f, "\n");
- if(onlyfirst)
- break;
- }
-}
-
-void cksum(void *hdr, size_t len)
-{
- struct icmphdr *ih;
- u_int8_t *cb;
- int i;
- int b1, b2;
-
- ih = (struct icmphdr *)hdr;
- cb = (u_int8_t *)hdr;
- ih->checksum = 0;
- b1 = b2 = 0;
- for(i = 0; i < (len & ~1); i += 2) {
- b1 += cb[i];
- b2 += cb[i + 1];
- }
- if(i & 1)
- b1 += cb[len - 1];
- while(1) {
- if(b1 >= 256) {
- b2 += b1 >> 8;
- b1 &= 0xff;
- continue;
- }
- if(b2 >= 256) {
- b1 += b2 >> 8;
- b2 &= 0xff;
- continue;
- }
- break;
- }
- cb = (u_int8_t *)&ih->checksum;
- cb[0] = ~(u_int8_t)b1;
- cb[1] = ~(u_int8_t)b2;
-}
-
-void usage(void)
-{
- fprintf(stderr, "usage: idnlookup [-hTa] [-t timeout] host\n");
-}
-
-int main(int argc, char **argv)
-{
- int ret;
- int s, c;
- int id;
- int namelen;
- struct reqhdr req;
- struct rephdr rep;
- struct iphdr iphdr;
- size_t hdrlen;
- struct addrinfo *ai, *cai, aihint;
- struct pollfd pfd;
- struct timeval tvb, tvc;
- struct sockaddr_storage name;
- int timeout, dispttl, onlyfirst;
- int elapsed, timedout, found;
-
- timeout = 3000;
- dispttl = 0;
- onlyfirst = 1;
- while((c = getopt(argc, argv, "haTt:")) != -1) {
- switch(c) {
- case 't':
- timeout = atoi(optarg);
- break;
- case 'a':
- onlyfirst = 0;
- break;
- case 'T':
- dispttl = 1;
- break;
- case 'h':
- case '?':
- case ':':
- default:
- usage();
- exit((c == 'h')?0:1);
- }
- }
-
- if(argc - optind < 1) {
- usage();
- exit(1);
- }
-
- memset(&aihint, 0, sizeof(aihint));
- aihint.ai_socktype = SOCK_RAW;
- aihint.ai_protocol = IPPROTO_ICMP;
- ret = getaddrinfo(argv[optind], NULL, &aihint, &ai);
-
- for(cai = ai; cai != NULL; cai = cai->ai_next) {
- if((s = socket(cai->ai_family, SOCK_RAW, IPPROTO_ICMP)) < 0) {
- perror("could not create raw socket");
- exit(1);
- }
-
- id = random() % 65536;
- memset(&req, 0, sizeof(req));
- req.type = ICMP_NAMEREQ;
- req.id = htons(id);
- cksum(&req, sizeof(req));
-
- ret = sendto(s, &req, sizeof(req), 0, cai->ai_addr, cai->ai_addrlen);
- if(ret < 0) {
- perror("sendto");
- exit(1);
- } else if(ret != sizeof(req)) {
- fprintf(stderr, "socket would not send entire packet\n");
- exit(1);
- }
-
- timedout = 0;
- found = 0;
- gettimeofday(&tvb, NULL);
- while(1) {
- pfd.fd = s;
- pfd.events = POLLIN;
- gettimeofday(&tvc, NULL);
- elapsed = ((tvc.tv_sec - tvb.tv_sec) * 1000) + ((tvc.tv_usec - tvb.tv_usec) / 1000);
- if(elapsed >= timeout) {
- timedout = 1;
- break;
- }
- ret = poll(&pfd, 1, timeout - elapsed);
- if(ret < 0) {
- perror("idnlookup: reading data");
- exit(1);
- }
-
- if(pfd.revents & POLLIN) {
- namelen = sizeof(name);
- ret = recvfrom(s, buf, sizeof(buf), 0, (struct sockaddr *)&name, &namelen);
- if(ret < 0) {
- perror("idnlookup: receiving data");
- exit(1);
- }
-
- if(name.ss_family != cai->ai_addr->sa_family)
- continue;
- if(name.ss_family == AF_INET) {
- if(memcmp(&(((struct sockaddr_in *)&name)->sin_addr), &(((struct sockaddr_in *)cai->ai_addr)->sin_addr), sizeof(struct in_addr)))
- continue;
- if(ret < sizeof(iphdr) + sizeof(rep))
- continue;
- hdrlen = sizeof(iphdr);
- memcpy(&iphdr, buf, sizeof(iphdr));
- if(iphdr.protocol != IPPROTO_ICMP)
- continue;
- } else if(name.ss_family == AF_INET6) {
- if(memcmp(&(((struct sockaddr_in6 *)&name)->sin6_addr), &(((struct sockaddr_in6 *)cai->ai_addr)->sin6_addr), sizeof(struct in6_addr)))
- continue;
- if(ret < sizeof(rep))
- continue;
- hdrlen = 0;
- } else {
- continue;
- }
-
- memcpy(&rep, buf + hdrlen, sizeof(rep));
- if(rep.type != ICMP_NAMEREP)
- continue;
- if((ntohs(rep.id) != id) || (ntohs(rep.seq != 0)))
- continue;
-
- found = 1;
- break;
- }
- }
-
- close(s);
-
- if(found) {
- if(dispttl)
- printf("%i\n", ntohl(rep.ttl));
- printdn(stdout, buf + hdrlen + sizeof(rep), ret - hdrlen - sizeof(rep), onlyfirst);
- break;
- }
- }
-
- if(timedout) {
- fprintf(stderr, "idnlookup: timeout\n");
- exit(1);
- }
-
- return(0);
-}
-
-/*
- * Local Variables:
- * compile-command: "gcc -Wall -g -o idnlookup idnlookup.c"
- * End:
- */
Dolda2000 GitWeb / icmp-dn.git / blobdiff