PenTest/nmap
1
0
Fork 0
mirror of https://github.com/nmap/nmap.git synced 2025-12-07 13:11:28 +00:00
Code Issues Projects Releases Wiki Activity

Use GetAdaptersAddresses, not Registry, for DNS servers

Browse Source 
In addition to being simpler, this approach allows us to limit to
adapters that are up and configured. Fixes #3114
This commit is contained in:
dmiller
2025-05-23 17:13:06 +00:00
parent a55708ba5e
commit d72beec963
1 changed files with 68 additions and 100 deletions
Download Patch File Download Diff File Expand all files Collapse all files

168
nmap_dns.cc
View File

@@ -119,8 +119,8 @@
#ifdef WIN32 #ifdef WIN32
#include "nmap_winconfig.h" #include "nmap_winconfig.h"
/* Need DnetName2PcapName */ #include <winsock2.h>
#include "libnetutil/netutil.h" #include <iphlpapi.h>
#endif #endif
#include "nmap.h" #include "nmap.h"
@@ -932,11 +932,30 @@ static void connect_evt_handler(nsock_pool nsp, nsock_event evt, void *srv_v) {
srv->status = dns_server::status_t::CONNECTED; srv->status = dns_server::status_t::CONNECTED;
} }
static void add_dns_server(const struct sockaddr_storage *addr, size_t addr_len, const char *hostname) {
std::list<dns_server>::iterator servI;
for(servI = servs.begin(); servI != servs.end(); servI++) {
// Already added!
if (memcmp(addr, &servI->addr, addr_len) == 0) break;
}
// If it hasn't already been added, add it!
if (servI == servs.end()) {
dns_server tpserv;
tpserv.hostname = hostname;
memcpy(&tpserv.addr, addr, addr_len);
tpserv.addr_len = addr_len;
servs.push_front(tpserv);
if (o.debugging) log_write(LOG_STDOUT, "mass_dns: Using DNS server %s\n", hostname);
}
}
// Adds DNS servers to the dns_server list. They can be separated by // Adds DNS servers to the dns_server list. They can be separated by
// commas or spaces - NOTE this doesn't actually do any connecting! // commas or spaces - NOTE this doesn't actually do any connecting!
static void add_dns_server(char *ipaddrs) { static void add_dns_server(char *ipaddrs) {
std::list<dns_server>::iterator servI;
const char *hostname; const char *hostname;
struct sockaddr_storage addr; struct sockaddr_storage addr;
size_t addr_len = sizeof(addr); size_t addr_len = sizeof(addr);
@@ -947,24 +966,7 @@ static void add_dns_server(char *ipaddrs) {
o.spoofsource ? o.af() : PF_UNSPEC) != 0) o.spoofsource ? o.af() : PF_UNSPEC) != 0)
continue; continue;
for(servI = servs.begin(); servI != servs.end(); servI++) { add_dns_server(&addr, addr_len, hostname);
// Already added!
if (memcmp(&addr, &servI->addr, sizeof(addr)) == 0) break;
}
// If it hasn't already been added, add it!
if (servI == servs.end()) {
dns_server tpserv;
tpserv.hostname = hostname;
memcpy(&tpserv.addr, &addr, sizeof(addr));
tpserv.addr_len = addr_len;
servs.push_front(tpserv);
if (o.debugging) log_write(LOG_STDOUT, "mass_dns: Using DNS server %s\n", hostname);
}
} }
} }
@@ -991,90 +993,56 @@ static void connect_dns_servers() {
#ifdef WIN32 #ifdef WIN32
static bool interface_is_known_by_guid(const char *guid) { void win32_get_servers() {
const struct interface_info *iflist; ULONG ret = ERROR_SUCCESS;
int i, n; std::vector<IP_ADAPTER_ADDRESSES> advec;
ULONG len = 0;
iflist = getinterfaces(&n, NULL, 0); for (int i=0; i < 3; i++) {
if (iflist == NULL) if (len == 0) {
return false; advec.resize(8);
}
for (i = 0; i < n; i++) { else {
char pcap_name[1024]; size_t count = len / sizeof(IP_ADAPTER_ADDRESSES);
const char *pcap_guid; advec.resize(count);
}
if (!DnetName2PcapName(iflist[i].devname, pcap_name, sizeof(pcap_name))) len = advec.size() * sizeof(IP_ADAPTER_ADDRESSES);
continue; ret = GetAdaptersAddresses(AF_UNSPEC, (
pcap_guid = strchr(pcap_name, '{'); GAA_FLAG_SKIP_UNICAST |
if (pcap_guid == NULL) GAA_FLAG_SKIP_ANYCAST |
continue; GAA_FLAG_SKIP_MULTICAST |
if (strcasecmp(guid, pcap_guid) == 0) GAA_FLAG_SKIP_FRIENDLY_NAME),
return true; NULL, &advec[0], &len);
if (ret != ERROR_BUFFER_OVERFLOW) {
break;
}
} }
if (ret != ERROR_SUCCESS) {
return false; error("Unable to get DNS servers: %08x", ret);
}
// Reads the Windows registry and adds all the nameservers found via the
// add_dns_server() function.
void win32_read_registry() {
HKEY hKey;
HKEY hKey2;
char keybasebuf[2048];
char buf[2048], keyname[2048], *p;
DWORD sz, i;
Snprintf(keybasebuf, sizeof(keybasebuf), "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters");
if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, keybasebuf,
0, KEY_READ, &hKey) != ERROR_SUCCESS) {
if (firstrun) error("mass_dns: warning: Error opening registry to read DNS servers. Try using --system-dns or specify valid servers with --dns-servers");
return; return;
} }
for (IP_ADAPTER_ADDRESSES *a = &advec[0]; a != NULL; a = a->Next) {
sz = sizeof(buf); if (a->OperStatus != IfOperStatusUp)
if (RegQueryValueEx(hKey, "NameServer", NULL, NULL, (LPBYTE) buf, (LPDWORD) &sz) == ERROR_SUCCESS) continue;
add_dns_server(buf); for (IP_ADAPTER_DNS_SERVER_ADDRESS_XP *d = a->FirstDnsServerAddress;
d != NULL; d = d->Next) {
sz = sizeof(buf); const sockaddr_storage* ss = (sockaddr_storage*)d->Address.lpSockaddr;
if (RegQueryValueEx(hKey, "DhcpNameServer", NULL, NULL, (LPBYTE) buf, (LPDWORD) &sz) == ERROR_SUCCESS) size_t sslen = d->Address.iSockaddrLength;
add_dns_server(buf); if (ss->ss_family == AF_INET) {
if (!a->Ipv4Enabled) continue;
RegCloseKey(hKey); }
else if (ss->ss_family == AF_INET6) {
Snprintf(keybasebuf, sizeof(keybasebuf), "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters\\Interfaces"); if (!a->Ipv6Enabled) continue;
if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, keybasebuf, /* Windows default site-local IPv6 DNS servers */
0, KEY_ENUMERATE_SUB_KEYS, &hKey) == ERROR_SUCCESS) { if (0 == memcmp(&((sockaddr_in6*)ss)->sin6_addr,
"\xfe\xc0\x00\x00\x00\x00\xff\xff", 8))
for (i=0; sz = sizeof(buf), RegEnumKeyEx(hKey, i, buf, &sz, NULL, NULL, NULL, NULL) != ERROR_NO_MORE_ITEMS; i++) { continue;
}
// If we don't have pcap, interface_is_known_by_guid will crash. Just use any servers we can find. else {
if (o.have_pcap && !interface_is_known_by_guid(buf)) { continue;
if (o.debugging > 1) }
log_write(LOG_PLAIN, "Interface %s is not known; ignoring its nameservers.\n", buf); add_dns_server(ss, sslen, inet_ntop_ez(ss, sslen));
continue;
}
Snprintf(keyname, sizeof(keyname), "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters\\Interfaces\\%s", buf);
if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, keyname,
0, KEY_READ, &hKey2) == ERROR_SUCCESS) {
sz = sizeof(buf);
if (RegQueryValueEx(hKey2, "DhcpNameServer", NULL, NULL, (LPBYTE) buf, (LPDWORD) &sz) == ERROR_SUCCESS)
add_dns_server(buf);
sz = sizeof(buf);
if (RegQueryValueEx(hKey2, "NameServer", NULL, NULL, (LPBYTE) buf, (LPDWORD) &sz) == ERROR_SUCCESS)
add_dns_server(buf);
RegCloseKey(hKey2);
}
} }
RegCloseKey(hKey);
} }
} }
#endif // WIN32 #endif // WIN32