X-Git-Url: http://dolda2000.com/gitweb/?a=blobdiff_plain;f=idnlookup.c;h=e97f62fd51360fca9a19e3955825605833bae081;hb=732b835938a7a80fe3c5ef71b84fa2ce0090bd01;hp=be4809bc934a443aa53a3e17c37b88dcbd6d2de6;hpb=e172b003e179ce9b70459eadbef8a73a4f218e0e;p=icmp-dn.git

diff --git a/idnlookup.c b/idnlookup.c
index be4809b..e97f62f 100644
--- a/idnlookup.c
+++ b/idnlookup.c
@@ -1,5 +1,6 @@
 /*
  *  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
@@ -25,6 +26,7 @@
 #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>
@@ -62,7 +64,7 @@ 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)
+void printdn(FILE *f, unsigned char *dnbuf, size_t size, int onlyfirst)
 {
     unsigned char *p;
     
@@ -80,6 +82,8 @@ void printdn(FILE *f, unsigned char *dnbuf, size_t size)
 	}
 	p++;
 	fprintf(f, "\n");
+	if(onlyfirst)
+	    break;
     }
 }
 
@@ -120,7 +124,7 @@ void cksum(void *hdr, size_t len)
 
 void usage(void)
 {
-    fprintf(stderr, "usage: idnlookup [-h] [-t timeout] host\n");
+    fprintf(stderr, "usage: idnlookup [-hTa] [-t timeout] host\n");
 }
 
 int main(int argc, char **argv)
@@ -132,20 +136,25 @@ int main(int argc, char **argv)
     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;
-    int elapsed;
+    int timeout, dispttl, onlyfirst;
+    int elapsed, timedout, found;
     
     timeout = 3000;
     dispttl = 0;
-    while((c = getopt(argc, argv, "hTt:")) != -1) {
+    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;
@@ -164,7 +173,6 @@ int main(int argc, char **argv)
     }
     
     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);
@@ -190,15 +198,17 @@ int main(int argc, char **argv)
 	    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) {
-		fprintf(stderr, "idnlookup: timeout\n");
-		exit(1);
+	    if(elapsed >= timeout) {
+		timedout = 1;
+		break;
 	    }
 	    ret = poll(&pfd, 1, timeout - elapsed);
 	    if(ret < 0) {
@@ -219,34 +229,53 @@ int main(int argc, char **argv)
 		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;
 		}
 		
-		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;
+		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;
 	    }
 	}
 	
-	if(dispttl)
-	    printf("%i\n", ntohl(rep.ttl));
-	printdn(stdout, buf + sizeof(iphdr) + sizeof(rep), ret - sizeof(iphdr) - sizeof(rep));
-	
 	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:
+ */