+/*
+ * idnlookup - ICMP Domain Name lookup utility for Linux
+ * 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 <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)
+{
+ 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);
+ }
+ printf("%.*s.", (int)*p, p + 1);
+ p += 1 + (int)*p;
+ }
+ p++;
+ printf("\n");
+ }
+}
+
+void cksum(void *hdr, size_t len)
+{
+ struct icmphdr *ih;
+ u_int8_t *cb;
+ int i;
+ u_int8_t 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];
+ cb = (u_int8_t *)&ih->checksum;
+ cb[0] = ~b1;
+ cb[1] = ~b2;
+}
+
+void usage(void)
+{
+ fprintf(stderr, "usage: idnlookup [-h] [-t timeout] host\n");
+}
+
int main(int argc, char **argv)
{
int ret;
- int s;
- struct sockaddr_in host;
- struct icmphdr data;
+ int s, c;
+ int id;
+ int namelen;
+ struct reqhdr req;
+ struct rephdr rep;
+ struct iphdr iphdr;
+ struct addrinfo *ai, *cai, aihint;
+ struct pollfd pfd;
+ struct timeval tvb, tvc;
+ struct sockaddr_storage name;
+ int timeout, elapsed;
- if((s = socket(PF_INET, SOCK_RAW, IPPROTO_ICMP)) < 0) {
- perror("could not create raw socket");
- exit(1);
+ timeout = 3000;
+ while((c = getopt(argc, argv, "ht:")) != -1) {
+ switch(c) {
+ case 't':
+ timeout = atoi(optarg);
+ break;
+ case 'h':
+ case '?':
+ case ':':
+ default:
+ usage();
+ exit((c == 'h')?0:1);
+ }
}
- host.sin_family = AF_INET;
- inet_aton("192.168.1.254", &host.sin_addr);
+ if(argc - optind < 1) {
+ usage();
+ exit(1);
+ }
- memset(&data, 0, sizeof(data));
- data.type = ICMP_NAMEREQ;
+ memset(&aihint, 0, sizeof(aihint));
+ aihint.ai_family = PF_INET; /* Only IPv4 for now. */
+ aihint.ai_socktype = SOCK_RAW;
+ aihint.ai_protocol = IPPROTO_ICMP;
+ ret = getaddrinfo(argv[optind], NULL, &aihint, &ai);
- ret = sendto(s, &data, sizeof(data), 0, (struct sockaddr *)&host, sizeof(host));
- if(ret < 0) {
- perror("sendto");
- } else {
- printf("%i\n", ret);
+ 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);
+ }
+
+ 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) {
+ fprintf(stderr, "idnlookup: timeout\n");
+ exit(1);
+ }
+ 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;
+ } 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;
+ } else {
+ continue;
+ }
+
+ if(ret < sizeof(iphdr) + sizeof(rep))
+ continue;
+ memcpy(&iphdr, buf, sizeof(iphdr));
+ memcpy(&rep, buf + sizeof(iphdr), sizeof(rep));
+ if(iphdr.protocol != IPPROTO_ICMP)
+ continue;
+ if(rep.type != ICMP_NAMEREP)
+ continue;
+ if((ntohs(rep.id) != id) || (ntohs(rep.seq != 0)))
+ continue;
+
+ break;
+ }
+ }
+
+ printdn(stdout, buf + sizeof(iphdr) + sizeof(rep), ret - sizeof(iphdr) - sizeof(rep));
+
+ close(s);
}
- close(s);
+
return(0);
}
Dolda2000 GitWeb / icmp-dn.git / commitdiff