udp scan (286fdf2d) · Commits · nimrod / masscan

src/main.c

+6 −23

Original line number	Diff line number	Diff line
		@@ -28,6 +28,8 @@
		#include "proto-arp.h" /* for responding to ARP requests */
		#include "proto-banner1.h" /* for snatching banners from systems */
		#include "proto-tcp.h" /* for TCP/IP connection table */
		#include "proto-preprocess.h" /* quick parse of packets */
		#include "proto-icmp.h" /* handle ICMP responses */
		#include "syn-cookie.h" /* for SYN-cookies on send */
		#include "output.h" /* for outputing results */
		#include "rte-ring.h" /* producer/consumer ring buffer */
		@@ -35,7 +37,6 @@
		#include "smack.h" /* Aho-corasick state-machine pattern-matcher */
		#include "pixie-timer.h" /* portable time functions */
		#include "pixie-threads.h" /* portable threads */
		#include "proto-preprocess.h" /* quick parse of packets */
		#include "templ-payloads.h" /* UDP packet payloads */

		#include <string.h>
		@@ -475,26 +476,7 @@ receive_thread(struct Masscan *masscan,
		LOG(4, "found udp 0x%08x\n", parsed.ip_dst);
		continue;
		case FOUND_ICMP:
		seqno_me = px[parsed.transport_offset+4]<<24
		\| px[parsed.transport_offset+5]<<16
		\| px[parsed.transport_offset+6]<<8
		\| px[parsed.transport_offset+7]<<0;

		if (syn_hash(ip_them, 65536*3+0) == seqno_me ) {
		LOG(4, "%u.%u.%u.%u - ICMP echo response: 0x%08x\n",
		(ip_them>>24)&0xff, (ip_them>>16)&0xff,
		(ip_them>>8)&0xff, (ip_them>>0)&0xff,
		seqno_me);
		output_report_status(
		out,
		Port_IcmpEchoResponse,
		ip_them,
		0,
		0,
		0);

		}

		handle_icmp(out, px, length, &parsed);
		continue;
		case FOUND_TCP:
		/* fall down to below */
		@@ -730,7 +712,8 @@ main_scan(struct Masscan *masscan)
		/*
		* Reconfigure the packet template according to command-line options
		*/
		if (masscan->adapter_port < 0x10000)
		if (masscan->adapter_port == 0x10000)
		masscan->adapter_port = 40000 + time(0) % 20000;
		template_set_source_port(tmplset, masscan->adapter_port);
		if (masscan->nmap.ttl)
		template_set_ttl(tmplset, masscan->nmap.ttl);

src/proto-preprocess.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -167,6 +167,8 @@ parse_udp:
		parse_icmp:
		{
		VERIFY_REMAINING(4, FOUND_ICMP);
		info->port_src = px[offset+0];
		info->port_dst = px[offset+1];
		return 1;
		}

src/templ-payloads.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -30,7 +30,7 @@ struct NmapPayloads {
		};

		struct Payload2 hard_coded_payloads[] = {
		{161, 65536, 56, 0,
		{161, 65536, 57, 0,
		"\x30" "\x37"
		"\x02\x01\x00" /* version */
		"\x04\x06" "public" /* community = public */
		@@ -51,7 +51,7 @@ struct Payload2 hard_coded_payloads[] = {
		"\x03" "www" "\x05" "yahoo" "\x03" "com" "\x00"
		"\x00\x01\x00\x01" /* A IN */
		},
		{5060, 65536, -1, 0,
		{5060, 65536, 0xFFFFFFFF, 0,
		"OPTIONS sip:carol@chicago.com SIP/2.0\r\n"
		"Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKhjhs8ass877\r\n"
		"Max-Forwards: 70\r\n"
		@@ -184,7 +184,6 @@ is_comment(const char *line)
		return 1;
		else
		return 0;
		return 0;
		}

		/***************************************************************************
		@@ -519,8 +518,8 @@ payloads_create()
		range.end = range.begin;

		length = hard_coded_payloads[i].length;
		if (length == -1)
		length = strlen(hard_coded_payloads[i].buf);
		if (length == 0xFFFFFFFF)
		length = (unsigned)strlen(hard_coded_payloads[i].buf);

		/* Add this to our real payloads. This will get overwritten
		* if the user adds their own with the same port */

src/templ-pkt.c

+58 −37

Original line number	Diff line number	Diff line
		@@ -18,7 +18,7 @@
		#include <assert.h>
		#include <string.h>
		#include <stdlib.h>

		#include <WinSock.h>
		static unsigned char default_tcp_template[] =
		"\0\1\2\3\4\5" /* Ethernet: destination */
		"\6\7\x8\x9\xa\xb" /* Ethernet: source */
		@@ -241,6 +241,8 @@ tcp_checksum(struct TemplatePacket *tmpl)
		return xsum;
		}



		/***************************************************************************
		***************************************************************************/
		unsigned
		@@ -251,7 +253,7 @@ udp_checksum2(const unsigned char *px, unsigned offset_ip,
		unsigned i;

		/* pseudo checksum */
		xsum = 6;
		xsum = 17;
		xsum += tcp_length;
		xsum += px[offset_ip + 12] << 8 \| px[offset_ip + 13];
		xsum += px[offset_ip + 14] << 8 \| px[offset_ip + 15];
		@@ -280,7 +282,7 @@ udp_checksum(struct TemplatePacket *tmpl)
		tmpl->packet,
		tmpl->offset_ip,
		tmpl->offset_tcp,
		tmpl->length - tmpl->offset_app);
		tmpl->length - tmpl->offset_tcp);
		}

		/***************************************************************************
		@@ -406,6 +408,32 @@ tcp_create_packet(
		return new_length;
		}

		/***************************************************************************
		***************************************************************************/
		static void
		udp_payload_fixup(struct TemplatePacket *tmpl, unsigned port, unsigned seqno)
		{
		const unsigned char *px2 = 0;
		unsigned length2 = 0;
		unsigned source_port2 = 0x1000;
		uint64_t xsum2 = 0;
		unsigned char *px = tmpl->packet;

		payloads_lookup(tmpl->payloads,
		port,
		&px2,
		&length2,
		&source_port2,
		&xsum2);

		memcpy( px+tmpl->offset_app,
		px2,
		length2);

		tmpl->length = tmpl->offset_app + length2;
		}


		/***************************************************************************
		* Here we take a packet template, parse it, then make it easier to work
		* with.
		@@ -434,6 +462,7 @@ template_set_target(
		else if (port < 65536*2) {
		tmpl = &tmplset->pkts[Proto_UDP];
		port &= 0xFFFF;
		udp_payload_fixup(tmpl, port, seqno);
		} else if (port < 65536*3) {
		tmpl = &tmplset->pkts[Proto_SCTP];
		port &= 0xFFFF;
		@@ -460,6 +489,11 @@ template_set_target(
		* Fill in the empty fields in the IP header and then re-calculate
		* the checksum.
		*/
		{
		unsigned total_length = tmpl->length - tmpl->offset_ip;
		px[offset_ip+2] = (unsigned char)(total_length>>8);
		px[offset_ip+3] = (unsigned char)(total_length>>0);
		}
		px[offset_ip+4] = (unsigned char)(ip_id >> 8);
		px[offset_ip+5] = (unsigned char)(ip_id & 0xFF);
		px[offset_ip+16] = (unsigned char)((ip >> 24) & 0xFF);
		@@ -468,6 +502,7 @@ template_set_target(
		px[offset_ip+19] = (unsigned char)((ip >> 0) & 0xFF);

		xsum = tmpl->checksum_ip;
		xsum += tmpl->length - tmpl->offset_app;
		xsum += (ip_id&0xFFFF);
		xsum += ip;
		xsum = (xsum >> 16) + (xsum & 0xFFFF);
		@@ -504,39 +539,25 @@ template_set_target(
		px[offset_tcp+17] = (unsigned char)(xsum >> 0);
		break;
		case Proto_UDP:
		{
		const unsigned char *px2;
		unsigned length2 = 0;
		unsigned source_port2;

		payloads_lookup(tmpl->payloads,
		port,
		&px2,
		&length2,
		&source_port2,
		&xsum);

		if (length2) {
		memcpy(&px[tmpl->offset_app], px2, length2);
		} else
		xsum = 0;
		tmpl->length = offset_tcp + length2 + 8;

		px[offset_tcp+ 2] = (unsigned char)(port >> 8);
		px[offset_tcp+ 3] = (unsigned char)(port & 0xFF);
		px[offset_tcp+ 4] = (unsigned char)((length2+8)>>8);
		px[offset_tcp+ 5] = (unsigned char)((length2+8)&0xFF);
		xsum += (uint64_t)tmpl->checksum_tcp
		px[offset_tcp+ 4] = (unsigned char)((tmpl->length - tmpl->offset_app + 8)>>8);
		px[offset_tcp+ 5] = (unsigned char)((tmpl->length - tmpl->offset_app + 8)&0xFF);

		px[offset_tcp+6] = (unsigned char)(0);
		px[offset_tcp+7] = (unsigned char)(0);
		xsum = udp_checksum(tmpl);
		/*xsum += (uint64_t)tmpl->checksum_tcp
		+ (uint64_t)ip
		+ (uint64_t)port
		+ (uint64_t)length2;
		+ (uint64_t)2*(tmpl->length - tmpl->offset_app);
		xsum = (xsum >> 16) + (xsum & 0xFFFF);
		xsum = (xsum >> 16) + (xsum & 0xFFFF);
		xsum = (xsum >> 16) + (xsum & 0xFFFF);
		printf("%04x\n", xsum);*/
		xsum = ~xsum;
		px[offset_tcp+6] = (unsigned char)(xsum >> 8);
		px[offset_tcp+7] = (unsigned char)(xsum >> 0);
		}
		break;
		case Proto_SCTP:
		break;

vs10/masscan.vcxproj

+2 −0

Original line number	Diff line number	Diff line
		@@ -25,6 +25,7 @@
		<ClCompile Include="..\src\out-text.c" />
		<ClCompile Include="..\src\out-xml.c" />
		<ClCompile Include="..\src\proto-banner1.c" />
		<ClCompile Include="..\src\proto-icmp.c" />
		<ClCompile Include="..\src\proto-tcp.c" />
		<ClCompile Include="..\src\logger.c" />
		<ClCompile Include="..\src\main-conf.c" />
		@@ -74,6 +75,7 @@
		<ClInclude Include="..\src\pixie-timer.h" />
		<ClInclude Include="..\src\proto-arp.h" />
		<ClInclude Include="..\src\proto-banner1.h" />
		<ClInclude Include="..\src\proto-icmp.h" />
		<ClInclude Include="..\src\proto-preprocess.h" />
		<ClInclude Include="..\src\proto-tcp.h" />
		<ClInclude Include="..\src\rand-blackrock.h" />