/***************************************************************************
* services.cc -- Various functions relating to reading the nmap-services *
* file and port <-> service mapping *
* *
***********************IMPORTANT NMAP LICENSE TERMS************************
* *
* The Nmap Security Scanner is (C) 1996-2008 Insecure.Com LLC. Nmap is *
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* software; you may redistribute and/or modify it under the terms of the *
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***************************************************************************/
/* $Id$ */
#include "services.h"
#include "NmapOps.h"
#include "charpool.h"
#include "nmap_error.h"
#include "utils.h"
extern NmapOps o;
static int numtcpports = 0;
static int numudpports = 0;
static struct service_list *service_table[SERVICE_TABLE_SIZE];
static struct service_list *sorted_services = NULL;
static int services_initialized = 0;
static int ratio_format = 0; // 0 = /etc/services no-ratio format. 1 = new nmap format
static int nmap_services_init() {
if (services_initialized) return 0;
char filename[512];
FILE *fp;
char servicename[128], proto[16];
u16 portno;
char *p;
char line[1024];
int lineno = 0;
struct service_list *current, *previous, *sp;
int res;
double ratio;
int ratio_n, ratio_d;
if (nmap_fetchfile(filename, sizeof(filename), "nmap-services") != 1) {
#ifndef WIN32
error("Unable to find nmap-services! Resorting to /etc/services");
strcpy(filename, "/etc/services");
#else
int len, wnt = GetVersion() < 0x80000000;
error("Unable to find nmap-services! Resorting to /etc/services");
if(wnt)
len = GetSystemDirectory(filename, 480); // be safe
else
len = GetWindowsDirectory(filename, 480); // be safe
if(!len)
error("Get%sDirectory failed (%d) @#!#@",
wnt ? "System" : "Windows", GetLastError());
else
{
if(wnt)
strcpy(filename + len, "\\drivers\\etc\\services");
else
strcpy(filename + len, "\\services");
}
#endif
}
fp = fopen(filename, "r");
if (!fp) {
fatal("Unable to open %s for reading service information", filename);
}
/* Record where this data file was found. */
o.loaded_data_files["nmap-services"] = filename;
memset(service_table, 0, sizeof(service_table));
while(fgets(line, sizeof(line), fp)) {
lineno++;
p = line;
while(*p && isspace((int) *p))
p++;
if (*p == '#')
continue;
res = sscanf(line, "%127s %hu/%15s %d/%d", servicename, &portno, proto, &ratio_n, &ratio_d);
if (res == 3) {
ratio = 0;
} else if (res == 5) {
if (ratio_n < 0 || ratio_d < 0)
fatal("%s:%d contains an invalid negative value", filename, lineno);
if (ratio_n > ratio_d)
fatal("%s:%d has a ratio %g. All ratios must be < 1", filename, lineno, (double)ratio_n/ratio_d);
if (ratio_d == 0)
fatal("%s:%d has a ratio denominator of 0 causing a division by 0 error", filename, lineno);
ratio = (double)ratio_n / ratio_d;
ratio_format = 1;
} else {
continue;
}
portno = htons(portno);
/* Now we make sure our service table doesn't have duplicates */
for(current = service_table[portno % SERVICE_TABLE_SIZE], previous = NULL;
current; current = current->next) {
if (portno == (u16) current->servent->s_port &&
strcasecmp(proto, current->servent->s_proto) == 0) {
if (o.debugging) {
error("Port %d proto %s is duplicated in services file %s", ntohs(portno), proto, filename);
}
break;
}
previous = current;
}
/* Current service in the file was a duplicate, get another one */
if (current)
continue;
if (strncasecmp(proto, "tcp", 3) == 0) {
numtcpports++;
} else if (strncasecmp(proto, "udp", 3) == 0) {
numudpports++;
} else if (strncasecmp(proto, "ddp", 3) == 0) {
/* ddp is some apple thing...we don't "do" that */
} else if (strncasecmp(proto, "divert", 6) == 0) {
/* divert sockets are for freebsd's natd */
} else if (strncasecmp(proto, "#", 1) == 0) {
/* possibly misplaced comment, but who cares? */
} else {
if (o.debugging)
error("Unknown protocol (%s) on line %d of services file %s.", proto, lineno, filename);
continue;
}
current = (struct service_list *) cp_alloc(sizeof(struct service_list));
current->servent = (struct servent *) cp_alloc(sizeof(struct servent));
current->ratio = ratio;
current->next = NULL;
if (previous == NULL) {
service_table[portno % SERVICE_TABLE_SIZE] = current;
} else {
previous->next = current;
}
current->servent->s_name = cp_strdup(servicename);
current->servent->s_port = portno;
current->servent->s_proto = cp_strdup(proto);
current->servent->s_aliases = NULL;
sp = (struct service_list *) cp_alloc(sizeof(struct service_list));
sp->servent = current->servent;
sp->ratio = current->ratio;
sp->next = NULL;
if (sorted_services == NULL || sorted_services->ratio < sp->ratio) {
sp->next = sorted_services;
sorted_services = sp;
} else
for (current=sorted_services;;current=current->next) {
if (current->next == NULL) {
current->next = sp;
break;
} else if (current->next->ratio < sp->ratio) {
sp->next = current->next;
current->next = sp;
break;
}
}
}
fclose(fp);
services_initialized = 1;
return 0;
}
/* Adds ports whose names match mask and one or more protocols
* specified by range_type to porttbl. Increases the respective
* protocol counts in ports.
* Returns the number of ports added in total.
*/
int addportsfromservmask(char *mask, u8 *porttbl, int range_type) {
struct service_list *current;
int bucket,t=0;
if (!services_initialized && nmap_services_init() == -1)
fatal("%s: Couldn't get port numbers", __func__);
for(bucket = 0; bucket < SERVICE_TABLE_SIZE; bucket++) {
for(current = service_table[bucket % SERVICE_TABLE_SIZE]; current; current = current->next) {
if (wildtest(mask, current->servent->s_name)) {
if ((range_type & SCAN_TCP_PORT) && strcmp(current->servent->s_proto, "tcp") == 0) {
porttbl[ntohs(current->servent->s_port)] |= SCAN_TCP_PORT;
t++;
}
if ((range_type & SCAN_UDP_PORT) && strcmp(current->servent->s_proto, "udp") == 0) {
porttbl[ntohs(current->servent->s_port)] |= SCAN_UDP_PORT;
t++;
}
}
}
}
return t;
}
struct servent *nmap_getservbyport(int port, const char *proto) {
struct service_list *current;
if (nmap_services_init() == -1)
return NULL;
for(current = service_table[port % SERVICE_TABLE_SIZE];
current; current = current->next) {
if (((u16) port == (u16) current->servent->s_port) &&
strcmp(proto, current->servent->s_proto) == 0)
return current->servent;
}
/* Couldn't find it ... oh well. */
return NULL;
}
static int port_compare(const void *a, const void *b) {
unsigned short ua = *((unsigned short *) a), ub = *((unsigned short *) b);
if (ua > ub) return 1;
else return -1;
}
// is_port_member() returns true if serv is an element of ptsdata.
// This could be implemented MUCH more efficiently but it should only be
// called when you use a non-default top-ports or port-ratio value TOGETHER WITH
// a -p portlist.
static int is_port_member(struct scan_lists *ptsdata, struct service_list *serv) {
int i;
if (serv->servent->s_proto[0] == 't') {
for (i=0; i<ptsdata->tcp_count; i++)
if (ntohs(serv->servent->s_port) == ptsdata->tcp_ports[i]) return 1;
} else {
for (i=0; i<ptsdata->udp_count; i++)
if (ntohs(serv->servent->s_port) == ptsdata->udp_ports[i]) return 1;
}
return 0;
}
// gettoppts() returns a scan_list with the most common ports scanned by
// Nmap according to the ratios specified in the nmap-services file.
//
// If level is below 1.0 then we treat it as a minimum ratio and we
// add all ports with ratios above level.
//
// If level is 1 or above, we treat it as a "top ports" directive
// and return the N highest ratio ports (where N==level).
//
// This function doesn't support IP protocol scan so only call this
// function if o.TCPScan() || o.UDPScan()
struct scan_lists *gettoppts(double level, char *portlist) {
int ti=0, ui=0;
struct scan_lists *sl, *ptsdata=NULL;
struct service_list *current;
if (!services_initialized && nmap_services_init() == -1)
fatal("%s: Couldn't get port numbers", __func__);
if (ratio_format == 0) {
if (level != -1)
fatal("Unable to use --top-ports or --port-ratio with an old style (no-ratio) services file");
if (portlist)
return getpts(portlist);
else if (o.fastscan)
return getpts("[-]");
else
return getpts("1-1024,[1025-]");
}
// TOP PORT DEFAULTS
if (level == -1) {
if (portlist)
return getpts(portlist);
if (o.fastscan) level = 100;
else level = 0.01;
}
sl = (struct scan_lists *) safe_zalloc(sizeof(struct scan_lists));
if (portlist) ptsdata = getpts(portlist);
if (level < 1) {
for (current=sorted_services; current; current=current->next) {
if (ptsdata && !is_port_member(ptsdata, current)) continue;
if (current->ratio >= level) {
if (o.TCPScan() && current->servent->s_proto[0] == 't') sl->tcp_count++;
else if (o.UDPScan() && current->servent->s_proto[0] == 'u') sl->udp_count++;
} else break;
}
if (sl->tcp_count)
sl->tcp_ports = (unsigned short *)safe_zalloc(sl->tcp_count * sizeof(unsigned short));
if (sl->udp_count)
sl->udp_ports = (unsigned short *)safe_zalloc(sl->udp_count * sizeof(unsigned short));
sl->prots = NULL;
for (current=sorted_services;current;current=current->next) {
if (ptsdata && !is_port_member(ptsdata, current)) continue;
if (current->ratio >= level) {
if (o.TCPScan() && current->servent->s_proto[0] == 't')
sl->tcp_ports[ti++] = ntohs(current->servent->s_port);
else if (o.UDPScan() && current->servent->s_proto[0] == 'u')
sl->udp_ports[ui++] = ntohs(current->servent->s_port);
} else break;
}
} else if (level >= 1) {
if (level > 65536)
fatal("Level argument to gettoppts (%g) is too large", level);
if (o.TCPScan()) {
sl->tcp_count = MIN((int) level, numtcpports);
sl->tcp_ports = (unsigned short *)safe_zalloc(sl->tcp_count * sizeof(unsigned short));
}
if (o.UDPScan()) {
sl->udp_count = MIN((int) level, numudpports);
sl->udp_ports = (unsigned short *)safe_zalloc(sl->udp_count * sizeof(unsigned short));
}
sl->prots = NULL;
for (current=sorted_services;current && (ti < sl->tcp_count || ui < sl->udp_count);current=current->next) {
if (ptsdata && !is_port_member(ptsdata, current)) continue;
if (o.TCPScan() && current->servent->s_proto[0] == 't' && ti < sl->tcp_count)
sl->tcp_ports[ti++] = ntohs(current->servent->s_port);
else if (o.UDPScan() && current->servent->s_proto[0] == 'u' && ui < sl->udp_count)
sl->udp_ports[ui++] = ntohs(current->servent->s_port);
}
if (ti < sl->tcp_count) sl->tcp_count = ti;
if (ui < sl->udp_count) sl->udp_count = ui;
} else
fatal("Argument to gettoppts (%g) should be a positive ratio below 1 or an integer of 1 or higher", level);
if (ptsdata) free_scan_lists(ptsdata);
if (sl->tcp_count > 1)
qsort(sl->tcp_ports, sl->tcp_count, sizeof(unsigned short), &port_compare);
if (sl->udp_count > 1)
qsort(sl->udp_ports, sl->udp_count, sizeof(unsigned short), &port_compare);
if (o.debugging && level < 1)
log_write(LOG_STDOUT, "PORTS: Using ports open on %g%% or more average hosts (TCP:%d, UDP:%d)\n", level*100, sl->tcp_count, sl->udp_count);
else if (o.debugging && level >= 1)
log_write(LOG_STDOUT, "PORTS: Using top %d ports found open (TCP:%d, UDP:%d)\n", (int) level, sl->tcp_count, sl->udp_count);
return sl;
}