Merge branch 'master' of github.com:zmap/zmap

src/Makefile

@@ -68,6 +68,12 @@ install: zmap
 	$(INSTALLDATA) ./zmap.1 $(mandir)
 	@echo "\n**************\nSuccess! ZMap is installed. Try running (as root):\nzmap -p 80 -N 10 -B 1M -o -\n**************"
 
+uninstall:
+	test -f $(oldmanfile) && rm -f $(oldmanfile) && mandb -f $(oldmanfile) || /bin/true # remove old man page if it's there
+	test -f $(mandir)/zmap.1 && rm -f $(mandir)/zmap.1 && mandb -f $(mandir)/zmap.1 || /bin/true # remove current man page if it's there
+	rm -f $(bindir)/zmap
+
+
 clean:
 	-rm -f $(objects) $(redis_objects) $(TARGETS)
 

src/get_gateway.c

@@ -131,11 +131,23 @@ int get_hw_addr(struct in_addr *gw_ip, char *iface, unsigned char *hw_mac)
 		while (RTA_OK(rt_attr, rt_len)) {
 			switch (rt_attr->rta_type) {
 			case NDA_LLADDR:
-				assert(RTA_PAYLOAD(rt_attr) == IFHWADDRLEN);
+				if (RTA_PAYLOAD(rt_attr) != IFHWADDRLEN) {
+					// could be using a VPN
+					log_fatal("get_gateway", "Unexpected hardware address length (%d).\n\n" \
+						"    If you are using a VPN, supply the --vpn flag (and provide an interface via -i)",
+						RTA_PAYLOAD(rt_attr));
+					exit(1);
+				}
 				memcpy(mac, RTA_DATA(rt_attr), IFHWADDRLEN);
 				break;
 			case NDA_DST:
-				assert(RTA_PAYLOAD(rt_attr) == sizeof(dst_ip));
+				if (RTA_PAYLOAD(rt_attr) != sizeof(dst_ip)) {
+					// could be using a VPN
+					log_fatal("get_gateway", "Unexpected IP address length (%d).\n" \
+						"    If you are using a VPN, supply the --vpn flag (and provide an interface via -i)",
+						RTA_PAYLOAD(rt_attr));
+					exit(1);
+				}
 				memcpy(&dst_ip, RTA_DATA(rt_attr), sizeof(dst_ip));
 				if (memcmp(&dst_ip, gw_ip, sizeof(dst_ip)) == 0) {
 					correct_ip = 1;

src/output_modules/module_json.c

@@ -159,7 +159,7 @@ int json_output_file_ip(fieldset_t *fs)
 		} else if (f->type == FS_NULL) {
 			// do nothing
 		} else {
-			log_fatal("csv", "received unknown output type");
+			log_fatal("json", "received unknown output type");
 		}
 	}
 

src/recv.c

@@ -59,6 +59,8 @@ static inline void set_ip(uint32_t ip)
 	ip_seen[ip >> 6] |= (uint64_t)1 << (ip & 0x3F);
 }
 
+static u_char fake_eth_hdr[65535];
+
 void packet_cb(u_char __attribute__((__unused__)) *user,
 		const struct pcap_pkthdr *p, const u_char *bytes)
 {
@@ -74,12 +76,12 @@ void packet_cb(u_char __attribute__((__unused__)) *user,
 	// length of entire packet captured by libpcap
 	uint32_t buflen = (uint32_t) p->caplen;
 
-	if ((sizeof(struct iphdr) + sizeof(struct ethhdr)) > buflen) {
+	if ((sizeof(struct iphdr) + (zconf.send_ip_pkts ? 0 : sizeof(struct ethhdr))) > buflen) {
 		// buffer not large enough to contain ethernet
 		// and ip headers. further action would overrun buf
 		return;
 	}
-	struct iphdr *ip_hdr = (struct iphdr *)&bytes[sizeof(struct ethhdr)];
+	struct iphdr *ip_hdr = (struct iphdr *)&bytes[(zconf.send_ip_pkts ? 0 : sizeof(struct ethhdr))];
 
 	uint32_t src_ip = ip_hdr->saddr;
 
@@ -88,7 +90,7 @@ void packet_cb(u_char __attribute__((__unused__)) *user,
 	// and we must calculate off potential payload message instead
 	validate_gen(ip_hdr->daddr, ip_hdr->saddr, (uint8_t *)validation);
 
-	if (!zconf.probe_module->validate_packet(ip_hdr, buflen - sizeof(struct ethhdr),
+	if (!zconf.probe_module->validate_packet(ip_hdr, buflen - (zconf.send_ip_pkts ? 0 : sizeof(struct ethhdr)),
 				&src_ip, validation)) {
 		return;
 	}
@@ -97,6 +99,18 @@ void packet_cb(u_char __attribute__((__unused__)) *user,
 
 	fieldset_t *fs = fs_new_fieldset();
 	fs_add_ip_fields(fs, ip_hdr);
+	// HACK:
+	// probe modules (for whatever reason) expect the full ethernet frame
+	// in process_packet. For VPN, we only get back an IP frame.
+	// Here, we fake an ethernet frame (which is initialized to
+	// have ETH_P_IP proto and 00s for dest/src).
+	if (zconf.send_ip_pkts) {
+		if (buflen > sizeof(fake_eth_hdr)) {
+			buflen = sizeof(fake_eth_hdr);
+		}
+		memcpy(&fake_eth_hdr[sizeof(struct ethhdr)], bytes, buflen);
+		bytes = fake_eth_hdr;
+	}
 	zconf.probe_module->process_packet(bytes, buflen, fs);
 	fs_add_system_fields(fs, is_repeat, zsend.complete);
 	int success_index = zconf.fsconf.success_index;
@@ -115,7 +129,6 @@ void packet_cb(u_char __attribute__((__unused__)) *user,
 				zrecv.cooldown_unique++;
 			}
 		}
-		
 	} else {
 		zrecv.failure_total++;
 	}
@@ -184,6 +197,11 @@ int recv_run(pthread_mutex_t *recv_ready_mutex)
 			log_fatal("recv", "couldn't install filter");
 		}
 	}
+	if (zconf.send_ip_pkts) {
+		struct ethhdr *eth = (struct ethhdr *)fake_eth_hdr;
+		memset(fake_eth_hdr, 0, sizeof(fake_eth_hdr));
+		eth->h_proto = htons(ETH_P_IP);
+	}
 	log_debug("recv", "receiver ready");
 	if (zconf.filter_duplicates) {
 		log_debug("recv", "duplicate responses will be excluded from output"); 

src/send.c

@@ -288,7 +288,7 @@ int send_run(int sock)
 				zconf.probe_module->print_packet(stdout, buf);
 			} else {
 					int l = zconf.probe_module->packet_length;
-					int rc = sendto(sock, buf, 
+					int rc = sendto(sock, buf + zconf.send_ip_pkts*sizeof(struct ethhdr),
 							l, 0,
 							(struct sockaddr *)&sockaddr,
 							sizeof(struct sockaddr_ll));

src/state.c

@@ -36,6 +36,7 @@ struct state_conf zconf = {
 	.probe_args = NULL,
 	.gw_mac = {0},
 	.gw_mac_set = 0,
+	.send_ip_pkts = 0,
 	.source_ip_first = NULL,
 	.source_ip_last = NULL,
 	.raw_output_fields = NULL,

src/state.h

@@ -71,6 +71,7 @@ struct state_conf {
 	char *output_args;
 	macaddr_t gw_mac[IFHWADDRLEN];
 	int gw_mac_set;
+	int send_ip_pkts;
 	char *source_ip_first;
 	char *source_ip_last;
 	char *output_filename;

src/zmap.1

@@ -84,6 +84,12 @@ Ethernet address.
 .TP
 .B \-i, --interface=name
 Specify network interface to use.
+.TP
+.B \-X, --vpn
+If using ZMap through a VPN, use this option. Instead of sending
+raw Ethernet frames, ZMap will send IP packets. When using this
+option, it is generally also necessary to provide the interface
+(through the -i flag).
 
 .SS "Advanced options"
 .TP

src/zmap.c

@@ -16,10 +16,12 @@
 #include <sched.h>
 #include <errno.h>
 
+#include <pwd.h>
 #include <net/if.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#include <sys/types.h>
 
 #include <pcap/pcap.h>
 
@@ -106,6 +108,17 @@ static void* start_recv(__attribute__((unused)) void *arg)
 	return NULL;
 }
 
+static void drop_privs()
+{
+	struct passwd *pw;
+	if ((pw = getpwnam("nobody")) != NULL) {
+		if (setuid(pw->pw_uid) == 0) {
+			return; // success
+		}
+	}
+	log_fatal("zmap", "Couldn't change UID to 'nobody'");		
+}
+
 static void *start_mon(__attribute__((unused)) void *arg)
 {
 	set_cpu();
@@ -261,6 +274,8 @@ static void start_zmap(void)
 		}
 	}
 
+	drop_privs();
+
 	// wait for completion
 	for (int i=0; i < zconf.senders; i++) {
 		int r = pthread_join(tsend[i], NULL);
@@ -382,6 +397,11 @@ int main(int argc, char *argv[])
 			exit(EXIT_FAILURE);
 		}
 	}
+	if (args.vpn_given) {
+		zconf.send_ip_pkts = 1;
+		zconf.gw_mac_set = 1;
+		memset(zconf.gw_mac, 0, IFHWADDRLEN);
+	}
 	if (cmdline_parser_required(&args, CMDLINE_PARSER_PACKAGE) != 0) {
 		exit(EXIT_FAILURE);
 	}

src/zopt.c

@@ -54,9 +54,10 @@ const char *gengetopt_args_info_help[] = {
   "  -S, --source-ip=ip|range      Source address(es) for scan packets",
   "  -G, --gateway-mac=addr        Specify gateway MAC address",
   "  -i, --interface=name          Specify network interface to use",
+  "  -X, --vpn                     Sends IP packets instead of Ethernet (for VPNs)",
   "\nAdvanced options:",
   "  -M, --probe-module=name       Select probe module  (default=`tcp_synscan')",
-  "  -O, --output-module=name      Select output module  (default=`csv')",
+  "  -O, --output-module=name      Select output module  (default=`simple_file')",
   "      --probe-args=args         Arguments to pass to probe module",
   "      --output-args=args        Arguments to pass to output module",
   "      --list-output-modules     List available output modules",
@@ -137,6 +138,7 @@ void clear_given (struct gengetopt_args_info *args_info)
   args_info->source_ip_given = 0 ;
   args_info->gateway_mac_given = 0 ;
   args_info->interface_given = 0 ;
+  args_info->vpn_given = 0 ;
   args_info->probe_module_given = 0 ;
   args_info->output_module_given = 0 ;
   args_info->probe_args_given = 0 ;
@@ -189,7 +191,7 @@ void clear_args (struct gengetopt_args_info *args_info)
   args_info->interface_orig = NULL;
   args_info->probe_module_arg = gengetopt_strdup ("tcp_synscan");
   args_info->probe_module_orig = NULL;
-  args_info->output_module_arg = gengetopt_strdup ("csv");
+  args_info->output_module_arg = gengetopt_strdup ("simple_file");
   args_info->output_module_orig = NULL;
   args_info->probe_args_arg = NULL;
   args_info->probe_args_orig = NULL;
@@ -226,19 +228,20 @@ void init_args_info(struct gengetopt_args_info *args_info)
   args_info->source_ip_help = gengetopt_args_info_help[19] ;
   args_info->gateway_mac_help = gengetopt_args_info_help[20] ;
   args_info->interface_help = gengetopt_args_info_help[21] ;
-  args_info->probe_module_help = gengetopt_args_info_help[23] ;
+  args_info->vpn_help = gengetopt_args_info_help[22] ;
-  args_info->output_module_help = gengetopt_args_info_help[24] ;
+  args_info->probe_module_help = gengetopt_args_info_help[24] ;
-  args_info->probe_args_help = gengetopt_args_info_help[25] ;
+  args_info->output_module_help = gengetopt_args_info_help[25] ;
-  args_info->output_args_help = gengetopt_args_info_help[26] ;
+  args_info->probe_args_help = gengetopt_args_info_help[26] ;
-  args_info->list_output_modules_help = gengetopt_args_info_help[27] ;
+  args_info->output_args_help = gengetopt_args_info_help[27] ;
-  args_info->list_probe_modules_help = gengetopt_args_info_help[28] ;
+  args_info->list_output_modules_help = gengetopt_args_info_help[28] ;
-  args_info->list_output_fields_help = gengetopt_args_info_help[29] ;
+  args_info->list_probe_modules_help = gengetopt_args_info_help[29] ;
-  args_info->config_help = gengetopt_args_info_help[31] ;
+  args_info->list_output_fields_help = gengetopt_args_info_help[30] ;
-  args_info->quiet_help = gengetopt_args_info_help[32] ;
+  args_info->config_help = gengetopt_args_info_help[32] ;
-  args_info->summary_help = gengetopt_args_info_help[33] ;
+  args_info->quiet_help = gengetopt_args_info_help[33] ;
-  args_info->verbosity_help = gengetopt_args_info_help[34] ;
+  args_info->summary_help = gengetopt_args_info_help[34] ;
-  args_info->help_help = gengetopt_args_info_help[35] ;
+  args_info->verbosity_help = gengetopt_args_info_help[35] ;
-  args_info->version_help = gengetopt_args_info_help[36] ;
+  args_info->help_help = gengetopt_args_info_help[36] ;
+  args_info->version_help = gengetopt_args_info_help[37] ;
   
 }
 
@@ -426,6 +429,8 @@ cmdline_parser_dump(FILE *outfile, struct gengetopt_args_info *args_info)
     write_into_file(outfile, "gateway-mac", args_info->gateway_mac_orig, 0);
   if (args_info->interface_given)
     write_into_file(outfile, "interface", args_info->interface_orig, 0);
+  if (args_info->vpn_given)
+    write_into_file(outfile, "vpn", 0, 0 );
   if (args_info->probe_module_given)
     write_into_file(outfile, "probe-module", args_info->probe_module_orig, 0);
   if (args_info->output_module_given)
@@ -721,6 +726,7 @@ cmdline_parser_internal (
         { "source-ip",	1, NULL, 'S' },
         { "gateway-mac",	1, NULL, 'G' },
         { "interface",	1, NULL, 'i' },
+        { "vpn",	0, NULL, 'X' },
         { "probe-module",	1, NULL, 'M' },
         { "output-module",	1, NULL, 'O' },
         { "probe-args",	1, NULL, 0 },
@@ -737,7 +743,7 @@ cmdline_parser_internal (
         { 0,  0, 0, 0 }
       };
 
-      c = getopt_long (argc, argv, "p:o:b:w:f:n:N:t:r:B:c:e:T:P:ds:S:G:i:M:O:C:qgv:hV", long_options, &option_index);
+      c = getopt_long (argc, argv, "p:o:b:w:f:n:N:t:r:B:c:e:T:P:ds:S:G:i:XM:O:C:qgv:hV", long_options, &option_index);
 
       if (c == -1) break;	/* Exit from `while (1)' loop.  */
 
@@ -970,6 +976,18 @@ cmdline_parser_internal (
               additional_error))
             goto failure;
         
+          break;
+        case 'X':	/* Sends IP packets instead of Ethernet (for VPNs).  */
+        
+        
+          if (update_arg( 0 , 
+               0 , &(args_info->vpn_given),
+              &(local_args_info.vpn_given), optarg, 0, 0, ARG_NO,
+              check_ambiguity, override, 0, 0,
+              "vpn", 'X',
+              additional_error))
+            goto failure;
+        
           break;
         case 'M':	/* Select probe module.  */
         

src/zopt.ggo

@@ -75,6 +75,8 @@ option "gateway-mac"		G "Specify gateway MAC address"
 option "interface"		i "Specify network interface to use"
 	   typestr="name"
 	   optional string
+option "vpn"		X "Sends IP packets instead of Ethernet (for VPNs)"
+	   optional
 
 section "Advanced options"
 

src/zopt.h

@@ -92,6 +92,7 @@ struct gengetopt_args_info
   char * interface_arg;	/**< @brief Specify network interface to use.  */
   char * interface_orig;	/**< @brief Specify network interface to use original value given at command line.  */
   const char *interface_help; /**< @brief Specify network interface to use help description.  */
+  const char *vpn_help; /**< @brief Sends IP packets instead of Ethernet (for VPNs) help description.  */
   char * probe_module_arg;	/**< @brief Select probe module (default='tcp_synscan').  */
   char * probe_module_orig;	/**< @brief Select probe module original value given at command line.  */
   const char *probe_module_help; /**< @brief Select probe module help description.  */
@@ -137,6 +138,7 @@ struct gengetopt_args_info
   unsigned int source_ip_given ;	/**< @brief Whether source-ip was given.  */
   unsigned int gateway_mac_given ;	/**< @brief Whether gateway-mac was given.  */
   unsigned int interface_given ;	/**< @brief Whether interface was given.  */
+  unsigned int vpn_given ;	/**< @brief Whether vpn was given.  */
   unsigned int probe_module_given ;	/**< @brief Whether probe-module was given.  */
   unsigned int output_module_given ;	/**< @brief Whether output-module was given.  */
   unsigned int probe_args_given ;	/**< @brief Whether probe-args was given.  */