#include "masscan.h" #include "util-logger.h" #include "rawsock.h" #include "rawsock-adapter.h" #include "stack-arpv4.h" #include "stack-ndpv6.h" #include "stub-pcap-dlt.h" /*************************************************************************** * Initialize the network adapter. * * This requires finding things like our IP address, MAC address, and router * MAC address. The user could configure these things manually instead. * * Note that we don't update the "static" configuration with the discovered * values, but instead return them as the "running" configuration. That's * so if we pause and resume a scan, auto discovered values don't get saved * in the configuration file. ***************************************************************************/ int masscan_initialize_adapter( struct Masscan *masscan, unsigned index, macaddress_t *source_mac, macaddress_t *router_mac_ipv4, macaddress_t *router_mac_ipv6 ) { char *ifname; char ifname2[256]; unsigned adapter_ip = 0; unsigned is_usable_ipv4 = !massip_has_ipv4_targets(&masscan->targets); /* I don't understand this line, seems opposite */ unsigned is_usable_ipv6 = !massip_has_ipv6_targets(&masscan->targets); /* I don't understand this line, seems opposite */ ipaddress_formatted_t fmt; /* * ADAPTER/NETWORK-INTERFACE * * If no network interface was configured, we need to go hunt down * the best Interface to use. We do this by choosing the first * interface with a "default route" (aka. "gateway") defined */ if (masscan->nic[index].ifname[0]) ifname = masscan->nic[index].ifname; else { /* no adapter specified, so find a default one */ int err; ifname2[0] = '\0'; err = rawsock_get_default_interface(ifname2, sizeof(ifname2)); if (err || ifname2[0] == '\0') { LOG(0, "[-] FAIL: could not determine default interface\n"); LOG(0, " [hint] try \"--interface ethX\"\n"); return -1; } ifname = ifname2; } LOG(1, "[+] interface = %s\n", ifname); /* * START ADAPTER * * Once we've figured out which adapter to use, we now need to * turn it on. */ masscan->nic[index].adapter = rawsock_init_adapter( ifname, masscan->is_pfring, masscan->is_sendq, masscan->nmap.packet_trace, masscan->is_offline, (void*)masscan->bpf_filter, masscan->nic[index].is_vlan, masscan->nic[index].vlan_id); if (masscan->nic[index].adapter == 0) { LOG(0, "[-] if:%s:init: failed\n", ifname); return -1; } masscan->nic[index].link_type = masscan->nic[index].adapter->link_type; LOG(1, "[+] interface-type = %u\n", masscan->nic[index].link_type); rawsock_ignore_transmits(masscan->nic[index].adapter, ifname); /* * MAC ADDRESS * * This is the address we send packets from. It actually doesn't really * matter what this address is, but to be a "responsible" citizen we * try to use the hardware address in the network card. */ if (masscan->nic[index].link_type == PCAP_DLT_NULL) { LOG(1, "[+] source-mac = %s\n", "none"); } else if (masscan->nic[index].link_type == PCAP_DLT_RAW) { LOG(1, "[+] source-mac = %s\n", "none"); } else { *source_mac = masscan->nic[index].source_mac; if (masscan->nic[index].my_mac_count == 0) { if (macaddress_is_zero(*source_mac)) { rawsock_get_adapter_mac(ifname, source_mac->addr); } /* If still zero, then print error message */ if (macaddress_is_zero(*source_mac)) { fprintf(stderr, "[-] FAIL: failed to detect MAC address of interface:" " \"%s\"\n", ifname); fprintf(stderr, " [hint] try something like " "\"--source-mac 00-11-22-33-44-55\"\n"); return -1; } } fmt = macaddress_fmt(*source_mac); LOG(1, "[+] source-mac = %s\n", fmt.string); } /* * IPv4 ADDRESS * * We need to figure out that IP address to send packets from. This * is done by querying the adapter (or configured by user). If the * adapter doesn't have one, then the user must configure one. */ if (massip_has_ipv4_targets(&masscan->targets)) { adapter_ip = masscan->nic[index].src.ipv4.first; if (adapter_ip == 0) { adapter_ip = rawsock_get_adapter_ip(ifname); masscan->nic[index].src.ipv4.first = adapter_ip; masscan->nic[index].src.ipv4.last = adapter_ip; masscan->nic[index].src.ipv4.range = 1; } if (adapter_ip == 0) { /* We appear to have IPv4 targets, yet we cannot find an adapter * to use for those targets. We are having trouble querying the * operating system stack. */ LOG(0, "[-] FAIL: failed to detect IP of interface \"%s\"\n", ifname); LOG(0, " [hint] did you spell the name correctly?\n"); LOG(0, " [hint] if it has no IP address, manually set with something like " "\"--source-ip 198.51.100.17\"\n"); if (massip_has_ipv4_targets(&masscan->targets)) { return -1; } } fmt = ipv4address_fmt(adapter_ip); LOG(1, "[+] source-ip = %s\n", fmt.string); if (adapter_ip != 0) is_usable_ipv4 = 1; /* * ROUTER MAC ADDRESS * * NOTE: this is one of the least understood aspects of the code. We must * send packets to the local router, which means the MAC address (not * IP address) of the router. * * Note: in order to ARP the router, we need to first enable the libpcap * code above. */ *router_mac_ipv4 = masscan->nic[index].router_mac_ipv4; if (masscan->is_offline) { /* If we are doing offline benchmarking/testing, then create * a fake MAC address fro the router */ memcpy(router_mac_ipv4->addr, "\x66\x55\x44\x33\x22\x11", 6); } else if (masscan->nic[index].link_type == PCAP_DLT_NULL) { /* If it's a VPN tunnel, then there is no Ethernet MAC address */ LOG(1, "[+] router-mac-ipv4 = %s\n", "implicit"); } else if (masscan->nic[index].link_type == PCAP_DLT_RAW) { /* If it's a VPN tunnel, then there is no Ethernet MAC address */ LOG(1, "[+] router-mac-ipv4 = %s\n", "implicit"); } else if (macaddress_is_zero(*router_mac_ipv4)) { ipv4address_t router_ipv4 = masscan->nic[index].router_ip; int err = 0; LOG(2, "[+] if(%s): looking for default gateway\n", ifname); if (router_ipv4 == 0) err = rawsock_get_default_gateway(ifname, &router_ipv4); if (err == 0) { fmt = ipv4address_fmt(router_ipv4); LOG(1, "[+] router-ip = %s\n", fmt.string); LOG(2, "[+] if(%s):arp: resolving IPv4 address\n", ifname); stack_arp_resolve( masscan->nic[index].adapter, adapter_ip, *source_mac, router_ipv4, router_mac_ipv4); } fmt = macaddress_fmt(*router_mac_ipv4); LOG(1, "[+] router-mac-ipv4 = %s\n", fmt.string); if (macaddress_is_zero(*router_mac_ipv4)) { fmt = ipv4address_fmt(masscan->nic[index].router_ip); LOG(0, "[-] FAIL: ARP timed-out resolving MAC address for router %s: \"%s\"\n", ifname, fmt.string); LOG(0, " [hint] try \"--router-ip 192.0.2.1\" to specify different router\n"); LOG(0, " [hint] try \"--router-mac 66-55-44-33-22-11\" instead to bypass ARP\n"); LOG(0, " [hint] try \"--interface eth0\" to change interface\n"); return -1; } } } /* * IPv6 ADDRESS * * We need to figure out that IPv6 address to send packets from. This * is done by querying the adapter (or configured by user). If the * adapter doesn't have one, then the user must configure one. */ if (massip_has_ipv6_targets(&masscan->targets)) { ipv6address adapter_ipv6 = masscan->nic[index].src.ipv6.first; if (ipv6address_is_zero(adapter_ipv6)) { adapter_ipv6 = rawsock_get_adapter_ipv6(ifname); masscan->nic[index].src.ipv6.first = adapter_ipv6; masscan->nic[index].src.ipv6.last = adapter_ipv6; masscan->nic[index].src.ipv6.range = 1; } if (ipv6address_is_zero(adapter_ipv6)) { fprintf(stderr, "[-] FAIL: failed to detect IPv6 address of interface \"%s\"\n", ifname); fprintf(stderr, " [hint] did you spell the name correctly?\n"); fprintf(stderr, " [hint] if it has no IP address, manually set with something like " "\"--source-ip 2001:3b8::1234\"\n"); return -1; } fmt = ipv6address_fmt(adapter_ipv6); LOG(1, "[+] source-ip = [%s]\n", fmt.string); is_usable_ipv6 = 1; /* * ROUTER MAC ADDRESS */ *router_mac_ipv6 = masscan->nic[index].router_mac_ipv6; if (masscan->is_offline) { memcpy(router_mac_ipv6->addr, "\x66\x55\x44\x33\x22\x11", 6); } if (macaddress_is_zero(*router_mac_ipv6)) { /* [synchronous] * Wait for router neighbor notification. This may take * some time */ stack_ndpv6_resolve( masscan->nic[index].adapter, adapter_ipv6, *source_mac, router_mac_ipv6); } fmt = macaddress_fmt(*router_mac_ipv6); LOG(1, "[+] router-mac-ipv6 = %s\n", fmt.string); if (macaddress_is_zero(*router_mac_ipv6)) { fmt = ipv4address_fmt(masscan->nic[index].router_ip); LOG(0, "[-] FAIL: NDP timed-out resolving MAC address for router %s: \"%s\"\n", ifname, fmt.string); LOG(0, " [hint] try \"--router-mac-ipv6 66-55-44-33-22-11\" instead to bypass ARP\n"); LOG(0, " [hint] try \"--interface eth0\" to change interface\n"); return -1; } } masscan->nic[index].is_usable = (is_usable_ipv4 & is_usable_ipv6); LOG(2, "[+] if(%s): initialization done.\n", ifname); return 0; }