From: Miek Gieben <miekg@NLnetLabs.nl>
Date: Thu, 2 Mar 2006 13:38:27 +0000 (+0000)
Subject: okay, when everything fails, do it brute force
X-Git-Tag: release-1.1.0~332
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f70907258d3ae6b5f6920ecfdc23ea29b464b4a2;p=thirdparty%2Fldns.git

okay, when everything fails, do it brute force

is it me, or do all udp dns pkt start at offset 42 ....
---

diff --git a/examples/ldns-pcap-drill.c b/examples/ldns-pcap-drill.c
index b5c92996..259f4ee6 100644
--- a/examples/ldns-pcap-drill.c
+++ b/examples/ldns-pcap-drill.c
@@ -1,9 +1,19 @@
 #include "config.h"
 
 #include <ldns/dns.h>
+#include <pcap.h>
 
-#include <netinet/ip6.h>
-#include <errno.h>
+
+#define ETHER_HDR_SIZE 14
+#define UDP_HDR_SIZE 8
+#define TCP_HDR_SIZE 0
+#define IP6_HDR_SIZE 40
+
+#ifndef ETHERTYPE_IPV6
+#define ETHERTYPE_IPV6 0x86dd
+#endif
+
+#define IP_HL(ip) 	(((ip)->ip_vhl) & 0x0f)
 
 /** 
  * general layout
@@ -17,9 +27,66 @@
  */
 
 int
-main(int argc, char **argv) 
+pcap2ldns_pkt_ip(const u_char *packet, struct pcap_pkthdr *h)
 {
+	uint16_t i;
+	ldns_status s = 0;
 	
-	return 1;
+	ldns_pkt *dns;
+
+	for(i = 0; i < h->caplen; i++) {
+		if ((s = ldns_wire2pkt(&dns, packet + i, (h->caplen - i))) == LDNS_STATUS_OK) {
+			printf("%d \n", i);
+			ldns_pkt_print(stdout, dns);
+		}
+	}
+	return 0;
+}
+
+int
+pcap2ldns_pkt(const u_char *packet, struct pcap_pkthdr *h)
+{
+	struct ether_header *eptr;
 
+	eptr = (struct ether_header *) h;
+	switch(eptr->ether_type) {
+		case ETHERTYPE_IP:
+			return pcap2ldns_pkt_ip(packet, h);
+			break;
+		case ETHERTYPE_IPV6:
+			/*
+			return pcap2ldns_pkt_ip6(packet, h);
+			*/
+			break;
+		case ETHERTYPE_ARP:
+			fprintf(stderr, "ARP pkt, dropping\n");
+			break;
+		default:
+			fprintf(stderr, "Not IP pkt, dropping\n");
+			break;
+	}
+	return 0;
 }
+
+int
+main(int argc, char **argv) 
+{
+	char errbuf[PCAP_ERRBUF_SIZE];
+	pcap_t *p;
+	struct pcap_pkthdr h;
+	const u_char *x;
+	size_t i = 0;
+
+	if (!(p = pcap_open_offline("/tmp/K/20011009-134418-q50000.pkt", errbuf))) {
+		printf("Cannot open pcap lib %s\n", errbuf);
+	}
+
+	while ((x = pcap_next(p, &h))) {
+		 pcap2ldns_pkt_ip(x, &h); 
+		i++;
+	}
+	printf("pkt seen %zd\n", i);
+	pcap_close(p);
+	return 0;
+}
+